Program for The 9th European Conference on Antennas and Propagation (EuCAP 2015)

Time Afonso De Albuquerque (Pav 3B) Bartolomeu Dias (Aud 4) Diogo Cão (Aud 8) Diogo De Silves (Room 1.08) Diogo De Teive (Room 1.07) Diogo Gomes (Room 1.06) Fernão M Pinto (Hall 4) Gil Eanes (Aud 3) Gil Vicente (Hall 5) Gonçalo V Cabral (Pav 5C) Infante D. Henrique (Aud 1) João G Zarco (Pav 3C) Luís De Camões (Hall 3) Museu De Marinha Paulo Da Gama (Pav 5B) Pedro A Cabral (Aud 2) Pêro Escobar (Pav 3A) Restaurant KAIS Tristão V Teixeira (Pav 5A)

Sunday, April 12

09:00-12:30       SC2: Multibeam Antennas and Beamforming Networks Design SC1: THz technology and instrumentation                             
14:00-17:30       SC6: Microwave imaging for medical diagnostics: from theory to implementation SC5: Adaptive Arrays Control: Theory and Techniques SC4: Gap waveguides for mmWve antenna systems and electronic packaging                          

Monday, April 13

09:00-10:00                     Opening Session                
10:00-12:30                     KS: Keynote Speakers                
13:40-15:40 W4 PropSim: Propagation Modelling and Simulation R1 Array: Array Antennas   WS2 RFID: Chipless RFID Future and Challenges       C21 EleSmall: [C] Electrically Small Antennas   HD2 mmWAnt: Millimetre-wave, submillimetre-wave and Terahertz antennas BA1 NumTech: Full Wave Computation and Numerical Techniques W5 IndoorProp: Indoor Propagation     S4 Multibeam: Multi-beam satellites C18 NF_EMC: [C] Deterministic & stochastic coupling analysis for Antennas, Near-Field & EMC applications CC3 AntSystem: Antenna systems and architectures   S1 AlphaSat: Alpha-Sat Experiment
16:10-18:10           C35 ModeBase: [C] Mode-based strategy for antenna analysis and design   DS1 Beamform: Beamforming and signal processing     MA3 PrintElem: Printed elements, baluns and associated circuits C29 BAN: [C] Measurements and Simulations in Channel Modelling in Wireless Body Area Networks C37 Mutual: [C] Mutual Coupling Formulation and its Effects in Antenna Systems   C43 PropSat: [C] Results of Ka and Q band propagation campaigns using Alphasat Aldo Paraboni and other Satellites
19:00-20:00                           Welcome Reception          

Tuesday, April 14

09:00-10:40 W3 ReconfAnt: Adaptive and reconfigurable antennas Bi5 PropBio: Propagation in Biomedical Environments C4 SimTools: [C] Advances in Commercial Electromagnetic Simulation Tools MA15 Multiband: Multiband and wideband antennas       MA13 Scattering: Scattering and Diffraction   C10 60GHz: [C] Antenna technologies for fixed wireless access at 60 GHz and above   MA4 EMI/EMC: EMI/EMC/PIM Chamber design, measurement and instrumentation     WS4 Julien: In Memoriam of Julien Perruisseau-Carrier C30 MiMed1: [C] Methodologies and modelling for EMF in medical diagnostics and therapy (MiMed) CC4 OTA: Over the Air (OTA) Testing in Antennas and Multiple Devices   S5 ArraySpace: Array Antennas for Space
11:10-12:50 MA16 InvScat: Imaging and Inverse Scattering           DS2 PropAeron: Propagation in Aeronautics and Navigation     CC5 UrbanProp: Urban Propagation  
14:00-15:00       WS5 R&S: Antenna Measurements at Rohde & Schwarz: The New Test Antenna Chamber     Poster P1: Propagation Poster Session 1   Poster A2: Antennas Poster Session 2       Poster A1: Antennas Poster Session 1            
15:00-16:20     Inv_1A: Invited Speakers Session 1A                         Inv_1B: Invited Speakers Session 1B      
16:50-18:30 C41 PropBuilt: [C] The IET session on Propagation in the built environment C23 MultiB: [C] Emerging techniques for multiband and wideband antennas C13 Graphene: [C] Applications of Graphene and Novel Materials at Terahertz and Microwaves         MA10 UWBAnt: UWB antennas and time-domain techniques   C8 AMTA2: [C] AMTA/EurAAP Measurements of integrated antennas at mm-wavelengths   MA12 EMTheory: Electromagnetic theory and numerical techniques     C25 Inkjet: [C] Inkjet Printed Antennas for Flexible, Wearable and Large Area Electronics Bi6 InvScat: Imaging and Inverse Scattering for Biomedical Applications C28 MMIMO: [C] Massive MIMO for 5G broadband communication networks   C38 Array: [C] Non-Uniform and Sparse Antenna Arrays - Innovative Concepts and Technological Solutions

Wednesday, April 15

09:00-10:40 C20 RadioC: [C] Dynamic radio channel modelling in mobile-to-mobile heterogeneous networks R2 LeakyAnt: Slotted-, guided- and leaky-wave antennas C26 INTELLE: [C] INTELLECT         C1 VISTA: [C] 2011-2015 early stage research in COST VISTA   C33 mmAnt: [C] Mm-wave Antenna Systems   C47 Security: [C] Wave-based sensing and imaging for security applications     C7 AMTA1: [C] AMTA/EurAAP Diagnostics, imaging, and post-processing in antenna measurements C44 MiMed2: [C] Therapeutic Applications of Electromagnetic Fields (MiMed) C15 Prop5G: [C] Channel measurements and modelling in the higher frequency bands for 5G   S2 SatProp: Satellite Propagation
11:10-12:10 W1 NetPlan: Network Planning, Optimisation and Simulation S8 MetaSpace: Advanced RF materials, metamaterials and EBG for Space Applications WS6 Altair: Application of Numerical Techniques to the Solution of Practical Antenna Problems with FEKO                
14:00-15:00       WS7 CST: CST Workshop: Advanced Antenna System Simulation     Poster P2: Propagation Poster Session 2   Poster A3: Antennas Poster Session 3       Poster A4: Antennas Poster Session 4            
15:00-16:20     Inv_2A: Invited Speakers Session 2A WS1 AMTA: AMTA Workshop: Measurement Techniques for Multi-beam Antennas                       Inv_2B: Invited Speakers Session 2B      
16:50-18:30 C17 DMC: [C] Dense Multipath Component (DMC) characterization for radio channel modeling MA6 MetaSurf: Metamaterial Lens and metasurfaces C26 INTELLE.: [C] INTELLECT.         C12 PowerTr: [C] Antennas and systems for Wireless Power Transmission in space applications   C36 Scatter: [C] Modelling scattering phenomena in wireless links   MA7 FSS: Frequency and polarization selective surfaces     C9 AMTA3: [C] AMTA/EurAAP Satellite and Aerospace Antenna Testing Bi3 Wearable: Wearable Antennas C40 PropGbit: [C] Propagation for multi-gigabit applications   C24 HighNorth: [C] High North Satellite Propagation
20:00-22:00                                   Conference Dinner  

Thursday, April 16

09:00-12:50 C39 PropVeh: [C] Propagation Channels for Wide-Sense Vehicle-to-X Communications MA1 Metamat: Metamaterials C14 Bench: [C] Combined Simulation/Measurement Benchmark For Challenging Antennas         MA11 Prop: Other Propagation Topics   C45 THz: [C] THz Antennas and Applications   MA8 AntMeasur: General Antenna Measurements     S3 TropProp: Tropospheric Propagation Bi1 CancerDet: Microwave Cancer Detection CC2 MIMO: MIMO, diversity, and smart antennas   S10 TransArray: Reflectarrays and transmitarrays
14:00-15:00       WS3 MiMed: Translating Microwave Medical Devices from Research Bench to Patient Bedside     Poster Awards: Awards Finalists Poster Session   Poster M1: Measurement Poster Session       Poster A5: Antennas Poster Session 5            
15:00-16:20     Inv_3A: Invited Speakers Session 3A                       Inv_3B: Invited Speakers Session 3B      
16:50-18:30 C32 OTA: [C] MIMO OTA Test Trade-offs MA5 MetaAnt: Metamaterials Antennas and Components C3 Nano: [C] Advanced computational methods and analysis of optical nanoantennas, resonators, and other photonic circuit components BA2 NearFarMe: Advances in near-field, far-field, compact and RCS test ranges       C48 WirelessTr: [C] Wireless Power Transmission and Energy Harvesting   HD1 Lenses: Lens antennas and radomes   C16 Confor: [C] Conformal Antennas       Bi4 AntCoupl: Antenna interactions and coupling C46 TuneSmall: [C] Tuning and Miniaturization Techniques for Small Device Antennas operating at LTE bands   C22 RFID: [C] Emerging chipless RFID technology trends

Friday, April 17

09:00-10:20 C34 Mobile: [C] Mobile antenna concepts leveraging circuit design techniques C27 Meta: [C] Latest Progress in Metamaterial-Based Antenna Design C19 DomainD: [C] Domain decomposition methods and macro-basis functions for integral equations         MA2 WireAnt: Wire antennas   C42 Pulsed: [C] Pulsed-field radio: theory, applications, implementation   C5 Plasma: [C] Advances in Plasma-based Antennas and Devices     S6 Reflector: Reflector, feed systems and components Bi2 BodyCom: Body-Centric Communications CC1 mmWProp: Propagation for mmW and 5G   C6 mmSpace: [C] Advances in space-fed antennas for millimeter-wave communications
10:50-12:10 W2 VehicProp: Propagation for Vehicle-to-X Communication C11 GeoSci: [C] Antennas and Propagation for Geoscience Applications           C2 3D: [C] 3D Printing / Additive Manufacturing Technology of Electromagnetic Structure   MA14 ActiveAnt: Active and integrated antennas   MA9 ConforAnt: Conformal antennas     S7 NumSpace: Electromagnetic theory and numerical techniques for Space Applications Bi7 SmallAnt: Small antennas and RF sensors C31 Microflu: [C] Microfluidics and Tunable Material Systems for Antenna Reconfiguration and Control   S9 AntSpace: Antennas for Space Applications
12:10-13:10     Closing Session                                

Sunday, April 12

Sunday, April 12 9:00 - 12:30 (Europe/Berlin)

SC1: THz technology and instrumentation 

Short Courses
Diogo de Teive (Room 1.07)
Chair: Miguel Navarro-Cía (University of Birmingham, United Kingdom (Great Britain))

SC2: Multibeam Antennas and Beamforming Networks Design

Short Courses
Diogo de Silves (Room 1.08)
Chairs: Piero Angeletti (European Space Agency, The Netherlands), Giovanni Toso (European Space Agency, ESA ESTEC, The Netherlands)

Sunday, April 12 14:00 - 17:30 (Europe/Berlin)

SC4: Gap waveguides for mmWve antenna systems and electronic packaging

Short Courses
Diogo Gomes (Room 1.06)
Chairs: Per-Simon Kildal (Chalmers University of Technology, Sweden), Ahmed Kishk (Concordia University, Canada), Ashraf Uz Zaman (Chalmers University of Technology, Sweden)

SC5: Adaptive Arrays Control: Theory and Techniques

Short Courses
Diogo de Teive (Room 1.07)
Chairs: Randy L. Haupt (Colorado School of Mines, USA), Paolo Rocca (University of Trento & ELEDIA Research Center, Italy)

SC6: Microwave imaging for medical diagnostics: from theory to implementation

Short Courses
Diogo de Silves (Room 1.08)
Chairs: Lorenzo Crocco (CNR - National Research Council of Italy, Italy), Panagiotis Kosmas (King's College London, United Kingdom (Great Britain))

Monday, April 13

Monday, April 13 9:00 - 10:00 (Europe/Berlin)

Opening Session

Room: Infante D. Henrique (Aud 1)

Monday, April 13 10:00 - 12:30 (Europe/Berlin)

KS: Keynote Speakers

Room: Infante D. Henrique (Aud 1)
Chair: Luis M. Correia (IST/INESC-ID - University of Lisbon & INESC, Portugal)
10:00 Antenna Research, Development and Measurement Facilities in Brazil: a Perspective From the Laboratory of Integration and Testing of the Brazilian Institute for Space Research
Geilson Loureiro (Brazilian Institute for Space Research, INPE & Technological Institute of Aeronautics ITA, Brazil)
This talk aims at presenting the Brazilian efforts for antenna related research and product development in Brazil from the perspective of the Laboratory of Integration and Testing (LIT) of INPE (The Brazilian Institute for Space Research). LIT is the main one of the two laboratories accredited to test antenna in Brazil. The life of an entrepreneur who manufactures and sells antennas in Brazil is not easy, even more if the manufacturing depends on the development of the product in Brazilian lands. Beyond the high taxes and the competition with Chinese products, there is still the process of approval by the Anatel and the lack of laboratory infrastructure. Anatel is the National Agency of Telecommunications; it sets the standards for approval of telecommunications products to be sold in Brazil. Thus, any antenna used to transmit signals must be tested and analyzed in accordance with the standards before being placed on the market. Such tests must be performed on the third party labs, but today the country has only two qualified laboratories. One of these is LIT, which currently has a far-field system, but is working to acquire three new systems, two near-field systems and a huge compact-range system. This fact will allow the country to test large antennas, communications satellites and will increase the capability for development and approval of new antennas.
10:40 Coffee Break
11:10 Wireless Dependable BAN of Things - Reliable Machine Centric Communications for Medicine, Cars, Energy, Smart City
Ryuji Kohno (Yokohama National University & University of Oulu, Japan)
Wireless body area network(BAN) has been researched and developed for ubiquitous and remote medicine and its international standard IEEE802.15.6 was established in February, 2012. Highly reliable and secure, i.e. dependable BAN can be applicable to a body of cars, buildings as well as a human body for dependable machine to machine (M2M) sensing and controlling. Such a M2M network can be called as "BAN of Things" like Internet of Things (IoT). To perform dependability of BAN, antenna and other radio technologies in physical layer must be jointly optimized with MAC, Network, and application layers. Even after BAN has been developed and standardized in global, regulatory science must be keen to guarantee safety, reliability and security to be compliant for regulation. This talk will introduce concept and possible manners of dependability in wireless BAN for medical healthcare, energy follow control, car controlling harness etc, i.e. Dependable BAN of Things.
11:50 The Wireless Big Bang
João Schwarz da Silva (University of Luxembourg, Luxembourg)
Progress in wireless communications in the past 30 years has been staggering. Soon we will emerge from the ICT era to enter into the Nano age where wireless technologies hold the promise of stopping the digital divide and contributing to expand human capabilities. The Internet will fully embrace the wireless technologies to become the nervous system of our society. The talk will review the progress made in wireless technologies and address some of the challenges ahead as we move towards such an all encompassing nervous Internet system. Issues such as spectrum, energy, health and radiation risks, cooperative networks and antenna design are amongst the questions that need being addressed. The promises are mindboggling but the threats are equally numerous. If we want the future wireless world to respond effectively to essential human requirements be it at the service level or at the resource level, more systemic approaches need to be considered. Beyond the technological and governance dimensions of the future network, care must be taken to ensure that ethical principles will drive us to this future where security and privacy of communications is guaranteed.

Monday, April 13 13:40 - 18:10 (Europe/Berlin)

BA1 NumTech: Full Wave Computation and Numerical Techniques

Antennas/Bridging other Areas
Room: Infante D. Henrique (Aud 1)
Chairs: Branko Kolundzija (University of Belgrade, Serbia), Francesca Vipiana (Politecnico di Torino, Italy)
13:40 Domain Decomposition Method for Integral Equations Using Non-Conformal Meshing
Mario Alberto Echeverri Bautista and Francesca Vipiana (Politecnico di Torino, Italy); Matteo Alessandro Francavilla (Istituto Superiore Mario Boella, Italy); Giuseppe Vecchi (Politecnico di Torino, Italy)
In this work a domain decomposition scheme for solving multi-scale perfect electric conductor structures is presented. The proposed strategy deals with non-conformal meshes, therefore decreasing the burden of re-meshing the entire structure for design and optimization analyses. The inner-outer scheme permits to address each sub-domain conditioning issues independently (e.g. using different preconditioning tactics), giving great flexibility respect to a fixed inner preconditioner for the entire structure.
14:00 Eliminating the DC Instability of the Time Domain Electric Field Integral Equation
Yves Beghein (Ghent University, Belgium); Kristof Cools (University of Nottingham, United Kingdom (Great Britain)); Francesco Andriulli (Ecole Nationale Superieure des Telecomunications de Bretagne, France)
Transient scattering of electromagnetic fields by perfect conductors is described by the time domain electric field integral equation (TD-EFIE). Discretizing this equation using a space-time Galerkin method results in a system of equations that can be solved by the marching on in time (MOT) algorithm. Unfortunately, the solution is plagued by spurious static currents (DC instability). In this contribution, a spatial Galerkin discretization is first applied to the TD-EFIE. Then, the discrete loop and star components of both basis and testing functions are separated using projection operators (thus avoiding the construction of a loop-star basis). The loop and star components are then rescaled with respect to each other by differentiating or integrating one of these components. This has the effect of removing the possibility for a DC signal to pollute the solution. A temporal Galerkin method then leads to a system that can be solved by the marching-on-in-time algorithm.
14:20 A Regularised Electric Field Integral Equation for Scattering by Perfectly Conducting Junctions
Kristof Cools (University of Nottingham, United Kingdom (Great Britain)); Francesco Andriulli (Ecole Nationale Superieure des Telecomunications de Bretagne, France)
The electric field integral equations or EFIE can be used to describe the scattering of a time harmonic electromagnetic wave by a perfect electrical conductor. Unfortunately the linear system resulting upon its discretization becomes increasingly ill-conditioned as the mesh parameter decreases. Because of this, the solution time increases faster than the number of degrees of freedom, precluding the design of a truly fast solver. For uncomplicated geometries, Calderon preconditioners have been described that provide a solution to this problem. Unfortunately, it is not easy to extend Calderon preconditioning to structures containing junctions, a case relevant to many applications. In this contribution a Calderon preconditioner for the EFIE in the presence of junctions is described. The preconditioner is based on a generalisation of the dual basis functions introduced by Buffa and Christiansen. Numerical examples ares presented that are evidence of the scheme's efficiency.
14:40 Robust, Efficient Evaluation of EM Green's Tensors in Generally Anisotropic, Planar-Stratified Media Via Complex-Plane Gauss-Laguerre Quadrature
Kamalesh Sainath (Ohio State University & ElectroScience Laboratory, USA); Fernando Teixeira (The Ohio State University, USA)
We outline and address computational challenges concerning the full-wave eigenfunction expansion of electromagnetic fields radiated by electric and (equivalent) magnetic current Hertzian (point) dipole antennas embedded in planar-stratified media of general anisotropy and loss. In particular, to rigorously treat problems where planar media of non-azimuthal-symmetric constitutive properties are present without resorting to analytical approximations, we address the direct numerical integration of the more general two-dimensional (2-D) Fourier (plane wave) integral transform rather than its one-dimensional variants. While arguably slower compared to other more approximate numerical methods, direct numerical integration touts generality of application with regard to problem geometry and rigorous error-control as virtues, justifying its use in myriad applications. Towards addressing many long-standing computational issues concerning the numerical integration, we propose a novel, robust formulation which not only addresses these issues but significantly improves the computational efficiency of the integration.
15:00 Plasmonic Transmission Lines Mode Solver Based on the Method of Moments
Mai Sallam (The American University in Cairo and Katholieke Universiteit Leuven); Guy Vandenbosch (Katholieke Universiteit Leuven (KU Leuven), Belgium); Georges Gielen (Katholieke Universiteit Leuven); Ezzeldin Soliman (The American University in Cairo, Egypt)
In this paper, we apply the integral equation formulation to calculate the mode characteristics of plasmonic transmission lines. These lines can be constructed from any number of arbitrarily shaped metallic strips placed inside a stack of planar dielectric or metallic layers. The number of the metallic strips determines the number of the propagating modes. Each mode is characterized by its attenuation constant, phase constant, and field distribution. The adopted formulation is based on solving Maxwell's equations using the Method of Moments (MoM) technique. This formulation is applied for single and coupled strips of various cross-sections over the frequency range 150-450 THz. Results are compared to Lumerical and CST software for the aim of verification. Good agreement between our solver and these tools can been observed.
15:20 Recovery-Based a Posteriori Error Estimation for the Charge in the Method of Moments
Willem J Strydom (Altair Development S.A. (Pty) Ltd, South Africa); Matthys M. Botha (Stellenbosch University, South Africa)
Error estimation for the method of moments (MoM) is a challenging task, due to the non-local nature of the integral operators involved. In this paper, various local recovery procedures are applied to the solution charge in a Rao-Wilton-Glisson (RWG) basis function-based MoM solution on a triangle element mesh, to obtain a higher-order charge representation. The MoM with RWG basis functions is routinely used for the numerical solution of electromagnetic surface integral equations. These recovered charge distributions are then used for a posteriori error estimation of the charge solution and their performance is compared. Such estimates could be incorporated into an adaptive solver scheme to optimize solution accuracy relative to computational cost. It is found that an RWG-based charge recovery procedure that was recently proposed by the present authors, yields the best performance.
15:40 Coffee Break
16:10 An NG-Based Algorithm for a Combined-Field Integral Formulation
Evgeny Chernokozhin (Tel Aviv University, Israel); Yaniv Brick (The University of Texas at Austin, USA); Amir Boag (Tel Aviv University, Israel)
A fast and stable algorithm for solving external problems of scalar scattering is implemented. The method employs a combined-field formulation, which provides stable convergence of the iterative solver, and a multilevel nonuniform grid (NG) based algorithm for the fast evaluation of field integrals to overcome the O(N2) computational complexity of the direct computation. The method is used for calculating the scattered fields by fairly large scatterers, including non convex bodies with piece-wise smooth surfaces.
16:30 Shaped Pattern Synthesis for Equispaced Linear Arrays with Non-Isotropic Antennas
Tom Bruintjes and Andre Kokkeler (University of Twente, The Netherlands); Georgios Karagiannis (Huawei Technologies, Germany); Gerard Smit (University of Twente, The Netherlands)
This paper explains how the measured directivity of antenna elements can be taken into account during shaped pattern synthesis. The method that is presented is based on the Orchard Elliott synthesis procedure. Important features of this classical way of synthesizing shaped antenna patterns are its high degree of control over the pattern's shape, and the flexible way in which the array excitations can be chosen. However, because it operates on the array factor, the directivity (i.e., element factor) of the antenna elements is neglected. Once synthesis is complete, and the element factor is reintroduced to evaluate the actual beam pattern, one often finds that the overall shape is not as it was specified. In particular when the shaped region of the pattern is placed further away from broadside, the differences become substantial. In those cases it may be necessary to take the element factor into account during synthesis.
16:50 GPU Acceleration of an Iterative Physical Optics Algorithm for the Analysis of Electrically Large Scatterers
Luca Pandolfo, Paolo De Vita and Mauro Bandinelli (IDS Ingegneria Dei Sistemi S. p. A, Italy); Giorgio Carluccio (Delft University of Technology, The Netherlands); Matteo Albani (University of Siena, Italy)
In this paper, a GPU accelerated implementation of an Iterative Physical Optics (IPO) algorithm is presented. The algorithm predicts multiple interactions between the objects comprised in electrically large scenarios under the Physical Optics (PO) approximation. NVIDIA CUDA is used to implement the GPU development. The double precision support offered by the Fermi architecture is used to provide a high level of accuracy. The CUDA implementation of the Jacobi and JMRES iterative methods is able to attain a speedup of 20 times over the 8 cores CPU OpenMP parallel execution.
17:10 Multiple Eigencurrents Expansion for the Solution of Wave Scattering From Anisotropic Bodies
Vito Lancellotti (Eindhoven University of Technology, The Netherlands)
We present the extension of the eigencurrents expansion method applied to the solution of wave scattering from clusters of anisotropic objects with different sizes and shapes and constitutive parameters. The problem is formulated with the linear embedding via Greens' operator (LEGO) approach, and the degrees of freedom are reduced by employing different sets of eigencurrents for representing the unknowns on the surface of the LEGO electromagnetic bricks. The "right" criterion for choosing the numbers of eigencurrents is discussed.
17:30 Hybrid Scattering-Admittance Operators for the Analysis of Finite Antenna Arrays
Salman Mokhlespour and Vito Lancellotti (Eindhoven University of Technology, The Netherlands); Anton G. Tijhuis (TU/e Eindhoven University of Technology, The Netherlands)
We describe the extension of the linear embedding via Green's operators (LEGO) approach to the solution of finite antenna arrays. The ultimate goal is the calculation of the admittance matrix of the array (receive mode) and the radiation pattern (transmit mode). As the basic idea is the inclusion of each array element inside a LEGO electromagnetic brick, the first step consists of the definition and numerical calculation of hybrid scattering-admittance operators which extend the notion of scattering operators of equivalent currents. In contrast, the combination of many LEGO bricks involves the usual transfer operators for the description of the multiple scattering phenomenon.
17:50 Physics-based Parametric Interpolation
Matteo Alessandro Francavilla (Istituto Superiore Mario Boella, Italy); Giorgio Giordanengo (LINKS Foundation & Politecnico di Torino, Italy); Marco Righero (LINKS Foundation, Italy); Giuseppe Vecchi and Francesca Vipiana (Politecnico di Torino, Italy)
A simple interpolation procedure is shown, able approximate the responses of electromagnetic simulations for different values of some parametrs describing the structures geometry. Basis functions are obtained from known family and from a post-process of some actual responses of the system. The fitting, in the least squares sense, can be handled efficiently leveraging on the Kronecker form of the resulting linear system.

Monday, April 13 13:40 - 15:40 (Europe/Berlin)

C18 NF_EMC: [C] Deterministic & stochastic coupling analysis for Antennas, Near-Field & EMC applications

Antennas/Multi Applications
Room: Pedro A Cabral (Aud 2)
Chairs: Sébastien Lalléchère (Université Clermont Auvergne, France), Blaise Ravelo (ESIGELEC, France)
13:40 Use of S-parameter Enclosed in Kron's Method for Electromagnetic Compatibility Computation
Olivier Maurice (AFSCET, France); Chaouki Kasmi (Technology Innovation Institute & Helmut Schmidt University, Faculty of Electrical Engineering, United Arab Emirates)
Kron's method has demonstrated its capability to established the equations of EMC problems on real systems. On another side, it's often easier to measure the S-parameters of equipment to extracted their equivalent electrical model. The purpose of this paper is to show how to include S-parameters measurements into Kron's system equations for EMC.
14:00 Functional Safety and EMC: Monte Carlo Study of the Impact of Function Redundancy on a System Immunity
Emmanuel Amador (EDF & EDF Lab, France); Nicolas Bouyge (EDF Lab & EDF, France)
Functional safety is a growing concern in the electromagnetic compatibility (EMC) community. In this article we propose to study the impact of the function redundancy on the overall system immunity to radiated emissions. An ideal case is presented and simulations of an equipment in a large enclosure show that a well-thought functional redundancy is necessary to decrease significantly the probability of a common mode aggression. Simple design rules can be applied and measurements show the validity of the approach and how functional safety can be tested in a reverberation chamber.
14:20 Statistical Analysis of Average and Maximum Crosstalks in Cable Bundles
Tarek Bdour (OSA Department, XLIM Research Institute, Limoges, France); Alain Reineix (University of Limoges, France)
In this paper, two complementary statistical approaches are suggested for the characterization of average and maximum conducted susceptibility in a non-uniform cable bundle. Response surface methodology (RSM) based on Design of Experiment (DOE) is applied for prediction of average current in victim wire within cable bundle. The effect of loads on current response and adequacy of the developed model have been evaluated successfully by Analysis of variance (ANOVA) test. The phenomenon of the occurrence of extreme crosstalk on victim wire and the quantification of extreme risk are studied by extreme value theory (EVT). We demonstrate that EVT can be successfully applied to predict maximum current corresponding to failure probability. In the present study, Generalized Pareto distribution (GPD) using Peak Over Threshold (POT) method was used to estimate the distribution of maximum current and gave appropriate results.
14:40 RF Exposure Assessment of Children's Organs Using Surrogate Model Built with Electromagnetic Solvers and Statistics
Joe Wiart (Telecom ParisTech, France); Pierric Kersaudy (Orange Labs, France); Amal Ghanmi (Univ MLV, France); Nadège Varsier and Abdelhamid Hadjem (Orange Labs, France); Odile Picon (Université Paris-Est Marne-la-Vallée, France)
The stochastic dosimetry is a novel approach combing numerical electromagnetic solver and statistics to manage the influence of variations of the inputs on the outputs of heavy dosimetric numerical calculations using a combination of deterministic and statistical methods. In this paper a method consisting in building a surrogate model based on a truncation of a Generalized Polynomial Chaos Expansion and characterize the SAR statistical distribution performed with 10,000 SAR estimations carried out with the surrogate substituted to the finite difference in time domain (FDTD) method FDTD. This method is applied to characterize the statistical distribution of SAR over 10g SAR induced in the organs of a child having a mobile phone, with 4 degrees of freedom, in the trouser pocket Equations
15:00 RF and EMC Investigation on CRIP System for the E-Healthcare CareStore Platform
Jorge Cabral (University of Minho & ALGORITMI Centre, Portugal); Blaise Ravelo (ESIGELEC, France); Christian Fischer Pedersen (Aarhus University, Denmark); Sébastien Lalléchère (Université Clermont Auvergne, France)
This paper is aimed to the RF coverage and electromagnetic compatibility (EMC) analyses of e-healthcare CareStore platform. The functioning principle of this innovative platform is described. Its RF hardware part named CRIP platform is composed of 2.4GHz BLE112 Bluetooth and NFC-RFID (ISO/IEC-18092) and biometrics (ISO/IEC-19794) readers as identification functions. The RF coverage of the CRIP Bluetooth antenna system in the indoor wireless communication scenario of multi-wall floor was investigated based on the multipath channel propagation ITU model. Then, the EMC qualification test results were presented with respect to the EU conformity with EN55022 for the emission and EN61000-3-4 for the radiated immunity. It was shown that the first version of CRIP device operates correctly under the EM radiation expected with this standard.
15:20 Statistical Approach of Ambient Electromagnetic Field Assessment with Body-Worn Multi-Axial Sensors
Christophe Roblin (Telecom ParisTech & LTCI - Institut Mines-Télécom, France)
The Electromagnetic Field exposure of the population due to wireless communications originates from both Down-Link and Up-Link emissions. Although the main contribution comes generally from the last, the former must be considered as well, as contributions can be competitive for some cases (e.g. in femtocells). Sensors and exposimeters networks (NW) can be deployed by the operators themselves (to enrich feedback information from the NW) or by independent external stakeholders such as regulatory agencies or local authorities. Electromagnetic simulations of a triaxial sensor – devoted to the evaluation of the field strength – placed at different positions of a set of whole body phantoms are presented. Proximity effects of the body are characterized statistically for polarimetric and non polarimetric measurements in various propagation scenarios.

C21 EleSmall: [C] Electrically Small Antennas

Antennas/Cellular Communications
Room: Gil Eanes (Aud 3)
Chairs: Christophe Fumeaux (The University of Adelaide & School of Electrical and Electronic Engineering, Australia), William Whittow (Loughborough University, United Kingdom (Great Britain))
13:40 Antennas for Mobile Communication Devices: What's Next?
Marta Martínez-Vázquez (IMST GmbH, Germany)
This paper provides an overview of the main challenges that will have to be addressed by antenna engineers, in order to provide innovative solutions for the upcoming 5G systems and services. Aspects like the integration of different applications and platforms, the challenge of multi-band, multi-antenna configurations, the migration towards higher frequencies and the interaction with the human operator are considered.
14:00 Multi-Feed NVIS Realization on Small Aircraft Using Characteristic Modes
Jeffrey Chalas (The Ohio State University & ElectroScience Lab, USA); Kubilay Sertel (The Ohio State University, USA); John L. Volakis (Florida International University, USA)
Characteristic modes (CMs) are used to design an NVIS antenna system on-board an electrically small UAV. Using the CMs of the UAV platform, near-vertical incident skywave (NVIS) are realized using pre-specified locations for antenna mounting. The appropriate excitation level of each monopole feed can be computed in a systematic manner using the CMs of the composite UAV + monopole antenna system. Discussions on pattern and bandwidth of this approach as a function of feeding element number will be presented, as well as discussions on further optimization approaches that can be effectively utilized from a characteristic modes perspective.
14:20 Compact Dual-mode Antenna for Body-centric Wireless Communications
Koichi Ito (Chiba University, Japan)
Body-centric wireless communications (BCWCs) have become an active area of research due to many applications such as medical care systems, identification systems and entertainment. In this paper, a compact dual-mode antenna for on-body and off-body communications is presented. In on-body mode, the antenna acts as an electrode which generates electric field distribution at 10 MHz. Therefore, significant low-power consumption can be realized for on-body communications. In off-body mode, the antenna radiates at the 2.45 GHz ISM band to communicate with an external device.
14:40 Considerations on SAR and Efficiency for W-BAN Antennas
Anja K. Skrivervik and Jovanche Trajkovikj (EPFL, Switzerland); Mohsen Koohestani (Ecole Supérieure d'Electronique de l'Ouest ESEO & Research Associate at IETR - UMR CNRS 6164, France); Nuno Pires (Geosatis SA & Instituto de Telecomunicações/Instituto Superior Técnico, Switzerland)
Wireless Body Area Networks have gained a large interest in the last decade. Antennas are a key component of such systems, as their characteristics and quality are predominant for the quality of the entire link. In this contribution, two major aspects of W-BAN antennas will be investigated: their coupling to the wearer, and their efficiency. The former is best characterized by the Specific Absorption Rate . Two scenarios will be considered, the first being a narrow band link at 380 MHz for security and rescue applications, the second a Ultra-WideBand link.
15:00 4G Cellular Antenna Design for Eyewear Devices
Aykut Cihangir (University of Nice Sophia Antipolis, France); Chinthana J Panagamuwa and William Whittow (Loughborough University, United Kingdom (Great Britain)); Gilles Jacquemod (University of Nice, France); Frédéric Gianesello (STMicroelectronics, France); Romain Pilard (STMicroelectronics, Technology R&D, STD, TPS Lab, France); Cyril Luxey (University Nice Sophia-Antipolis, France)
An antenna structure to cover the 4G LTE-Advanced cellular communication bands in a smart eyewear device is presented in this paper. The antenna consists of a capacitive coupling element printed on FR4 substrate with a three element matching network. A dielectric frame, to represent the smart eyewear device is designed and manufactured using 3-D printing technology. Simulations and measurements of the antenna with the dielectric frame were performed for three use-cases: in free space; with the head of the user; with both head and hand. Reflection coefficient and total efficiency measurements show good agreement with simulations.
15:20 Optimizing Small Wideband Antenna Performance for Both RIMP and Random-LOS
Per-Simon Kildal (Chalmers University of Technology, Sweden); Xiaoming Chen (Xi'an Jiaotong University, China); Andrés Alayón Glazunov (University of Twente, The Netherlands & Chalmers University of Technology, Sweden)
Rich Isotropic Multipath (RIMP) environment like reverberation chamber (RC) has proven to be useful for characterizing mobile LTE devices. The user statistics have larger effect in environments with stronger Line-Of-Sight (LOS), because the angle of arrival (AoA) and the polarization of the LOS contribution become randomized due to the user. Thus, we introduce the term random-LOS. The present paper elaborates on characterization of an example antenna in both RIMP and random-LOS. We show how to characterize the micro BTS by the probability of detection (PoD) of one and more bitstreams in both RIMP and random-LOS, by considering the user randomly located and oriented within the angular coverage sector. We limit the treatment to a wall-mounted BTS antenna, and assume a desired hemi-spherical coverage.

CC3 AntSystem: Antenna systems and architectures

Antennas/Cellular Communications
Room: Pêro Escobar (Pav 3A)
Chairs: Georgia E. Athanasiadou (University of Peloponnese, Greece), Koen Mouthaan (National University of Singapore, Singapore)
13:40 The Effects of Antenna Array Size and Back Lobe Level on Self-Interference and Transmitted Powers for 4G Beamforming Multicell Systems with In-Band Full Duplex Relays
Dimitra Zarbouti, George Tsoulos and Georgia E. Athanasiadou (University of Peloponnese, Greece)
This paper considers a 4G multicell system where base-stations and relays employ typical or large size antenna arrays with beamforming capabilities, as well as in-band full duplex relays. The achieved SIR gain can be exploited either for reducing the major problem of full duplex self-interference, or for reducing the backhaul and access link powers. The analysis and the produced results indicate that using 'small' antenna arrays with 8 elements can lower the requirement of full duplex self-interference cancellation by up to 50/70dB if the back lobe of the produced radiation pattern is kept to -20/-30dB. The same scenario with a large antenna array of 1024 elements gives 90/110dB reduction, respectively. Additionally, both the backhaul and access transmitted powers can be reduced by 30dB and 25dB with 1024 elements, while if the back lobe level is -20dB then the backhaul power reduction increases to 55dB.
14:00 Reconfigurable LTE MIMO Automotive Antenna System Based on the Characteristic Mode Analysis
Eugen Safin (University of Kiel, Germany); Risto Valkonen (Nokia Bell Labs, Finland); Dirk Manteuffel (University of Hannover, Germany)
In this paper we present a frequency reconfigurable LTE MIMO antenna for automotive applications based on the characteristic mode theory. Capacitive coupling elements are used for the excitation of surface wave modes of the given chassis in order to design an uncoupled two port antenna system. A feeding network with a reconfigurable LTCC impedance matching is presented and evaluated.
14:20 High Resolution ESM/ELINT DOA Estimation with Super-Heterodyne Multi-Octave Antenna System
Ivan Russo (Elettronica S.p.A., Italy); Paolo Baldonero and Antonio Manna (Elettronica SpA, Italy); Daniele Marcantoni and Fabrizio Trotta (Elettronica S.p.A., Italy)
This paper describes a compact antenna system architecture for DOA estimation in electronic warfare environments. The single antenna modules are intended to cover a certain frequency range each. This super-heterodyne approach allows covering a bandwidth larger than four octaves. Throughout the document, it is also shown how amplitude/phase mixed DOA algorithms allow better angular accuracy than amplitude-based methods.
14:40 Quad-Polarized Wideband Phased Array with Reduced Sidelobes by Interstitial-Packing
Hongzhao Ray Fang and Ramanan Balakrishnan (National University of Singapore, Singapore); Regis Guinvarc'h (CentraleSupelec, France); Koen Mouthaan (National University of Singapore, Singapore)
A quad-polarized wideband phased array antenna system using wideband sinuous antennas is developed and wideband beamforming is demonstrated. The design of wideband sinuous antenna elements as well as the development of the antenna feed network, comprising of a wideband beamformer and polarizer network, is described. To reduce grating lobe effects at higher frequencies, the interstices of the antenna array are filled with smaller antenna elements. For a frequency band of 0.6 GHz to 2.4 GHz, no grating lobes are observed when the beam points at boresight. In comparison, a linear array of sinuous antennas exhibits grating lobes from 1.6 GHz for the same scan angle.
15:00 Generation of OAM Radio Waves with Three Polarizations Using Circular Horn Antenna Array
Xudong Bai (Shanghai Aerospace Electronics Co., Ltd, China); Xianling Liang (Shanghai Jiaotong University, China); Ronghong Jin (Shanghai Jiao Tong University, China); Junping Geng (Shanghai Jiaotong University, China)
An effective solution of generating OAM-carrying radio beams with three polarizations is provided. Through the reasonable configuration of phased antenna array using elements with three polarizations, the OAM radio waves with three polarizations for different states can be generated. The vectors of electric fields with different OAM states for linear, as well as left or right circular polarizations are presented and analyzed in detail. The superposition of two coaxial OAM states is also carried out, and the general conclusion is provided.
15:20 Impedance Characterization of UHF RFID IC and Tag Performance
Aline Coelho de Souza (IMEP-LAHC, France); Yvan Duroc (University Claude-Bernard Lyon 1, France); Tan Phu Vuong (Grenoble INP, France); Alexandre Luce (LNE, France)
This abstract presents a study about the performance of tags matched to different values of antenna impedance according to received power level. The impedance of a commercial RFID IC was measured in function of power and two values of impedance are selected. Three antenna designs were developed to analyze the prototypes performance. The results of this study provide knowledge for tag antenna design matched to complex impedance different from the complex conjugate given in RFID IC datasheet.

Monday, April 13 13:40 - 18:10 (Europe/Berlin)

HD2 mmWAnt: Millimetre-wave, submillimetre-wave and Terahertz antennas

Antennas/High Data-rate Transfer
Room: Gonçalo V Cabral (Pav 5C)
Chairs: Daniele Cavallo (Delft University of Technology, The Netherlands), Jian Yang (Chalmers University of Technology, Sweden)
13:40 Rectangular to Large Diameter Conical Corrugated Waveguide Converter Based on Stacked Rings
Stephen Doherty (National University of Ireland Maynooth, Ireland); Arndt von Bieren (SWISSto12 SA, Switzerland); Fiachra Cahill (Maynooth University, Ireland); Alessadro Macor and Emile de Rijk (SWISSto12 SA, Switzerland); Neil Trappe (NUI Maynooth, Ireland); Mathieu Billod (SWISSto12 SA, Switzerland); Creidhe O'Sullivan (National University of Ireland Maynooth, Ireland); Mirko Favre (SWISSto12 SA, Switzerland); Marcin Gradziel (National University of Ireland, Maynooth, Ireland); John Anthony Murphy (National University of Ireland Maynooth, Ireland)
This paper presents the design of a high frequency (500 - 750 GHz) converter based on stacked rings technology for the purpose of optimising the coupling to a large diameter (5 mm) conical corrugated waveguide network from a standard WM- 380 rectangular aperture. An in-house piece of mode matching software (SCATTER) is adopted for the design process and the level of HE11 modal purity taken as the most appropriate metric to ensure low transmission loss. The results of a trade off analysis between linear and sine-squared profile designs as a function of the total converter length are presented. A final prototype of a linear model is manufactured using stacked rings and demonstrates promising performance.
14:00 High Gain Flat Sinusoidal Bull's Eye Leaky Millimetre-Wave Antenna
Unai Beaskoetxea (Anteral, Spain); Victor Pacheco-Peña (Universidad Publica de Navarra, Spain); Bakhtiyar Orazbayev (EPFL & The Laboratory of Wave Engineering, Switzerland); Tahsin Akalin (Lille University, France); Stefano Maci (University of Siena, Italy); Miguel Navarro-Cía (University of Birmingham, United Kingdom (Great Britain)); Miguel Beruete (Universidad Publica de Navarra, Spain)
A sinusoidally corrugated periodic Bull's-Eye leaky wave antenna operating at 77 GHz is numerically and experimentally analyzed. Gain enhancement and bandwidth narrowing are observed as the number of periods is increased. Numerical and experimental results are in good agreement for the fabricated 20 period sinusoidal structure, showing a 28.9 dB gain with less than -20 dB side lobe level and a very narrow 1.2deg near broadside beam.
14:20 A 76.5 GHz Microstrip Comb-Line Antenna Array for Automotive Radar System
Dapeng Wu (Chalmers University of Technology, Sweden); Ziqiang Tong (Freescale, Germany); Ralf Reuter (Freescale Semiconductor, Germany); Heiko Gulan (Karlsruhe Institute of Technology, Germany); Jian Yang (Chalmers University of Technology, Sweden)
This paper presents a 45 degree linearly polarized microstrip comb-line antenna array for the 76.5 GHz automotive radar system. The 13-element array is implemented on Rogers RO3003 substrate with a size of 20 × 2 mm2. The measured gain of the antenna is 11.4 dBi and the sidelobe level is below -16.5 dB at 76.5 GHz.
14:40 Modeling and Design of Parallel-Fed Continuous Transverse Stub (CTS) Arrays
Francesco Foglia Manzillo (CEA-LETI, France); Mauro Ettorre (University of Rennes 1 & UMR CNRS 6164, France); Massimiliano Casaletti (Sorbonne Universités UPMC, France); Ronan Sauleau (University of Rennes 1, France); Nicolas Capet (ANYWAVES FRANCE, France)
This work presents a rigorous and efficient framework for the analysis of continuous transverse stub (CTS) arrays, based on a mode-matching technique. The model focuses on an infinite array of long slots fed in parallel by parallel plate waveguides (PPWs). Closed-form expressions are provided for the active impedance of the array. The accuracy and the simplicity of the model are due to an effective decomposition of the equivalent currents over the slots in PPW modes. An excellent agreement with full-wave simulations is achieved. The developed fast code has been used for the design of a flat, broadband 16-elements CTS array in Ka-band. The main beam can be steered mechanically in H-plane. The antenna exhibits in simulations a gain higher than 28 dBi in the band 27.5-31 GHz, within a -30° to 30° scanning range. A prototype has been manufactured and experimental results will be soon available.
15:00 Analysis and Optical Characterisation of Bolometric Integrating Cavities Including a Free Space Gap in the Waveguide Structure
Darragh McCarthy (National University of Ireland Maynooth, Ireland); Neil Trappe (NUI Maynooth, Ireland); Stephen Doherty, John Anthony Murphy and Colm Bracken (National University of Ireland Maynooth, Ireland); Marcin Gradziel (National University of Ireland, Maynooth, Ireland); Creidhe O'Sullivan (National University of Ireland Maynooth, Ireland); Maarten van der Vorst (European Space Agency, The Netherlands); Michael Audley and Gert de Lange (SRON Netherlands Organization for Space Research, The Netherlands)
Bolometric integrating cavities have been used with great success in previous far-infrared space missions, and are planned for extensive use in future missions where ever increasing sensitivity is required. It is critical for the purposes of design and the interpretation of results that these systems are thoroughly understood and optically characterised fully. Such systems, for manufacturing and mechanical reasons, may contain free space gaps between the feed horn antenna and the integrating cavity, and so it is necessary to include the effect of these waveguide openings in simulations. Since these pixels are electrically large, it is more feasible to model them by using the computationally efficient mode-matching approach. In this paper we discuss the elements required to model such pixels within the mode-matching approach and apply it to a typical pixel containing a free space gap, based on an experimental Transition Edge Sensor (TES) cavity waveguide pixel at SRON Groningen.
15:20 Design of Millimeter-Wave Wideband Gap Waveguide Transitions Considering Integration Into the Antenna System
Astrid Algaba Brazález (Ericsson Research, Ericsson AB, Sweden); Eva Rajo-Iglesias (University Carlos III of Madrid, Spain); Per-Simon Kildal (Chalmers University of Technology, Sweden)
Two wideband vertical transitions from inverted microstrip gap waveguide to rectangular waveguide (WR-15) for 60 GHz antenna array applications are proposed. These transitions are aimed to interconnect the WR-15 with the gap waveguide feed-network employed to provide feeding to the radiating elements of slot/horn antenna arrays. The wideband field transformation is achieved without the need of adding a quarter-wavelength cavity backshort on a metal block placed over the transition. First, we replace this backshort by creating a cavity in the radiating layer when this is made in Substrate Integrated Waveguide (SIW) technology, and thereafter we use an air-filled pin cavity in the radiating layer. The simulated Sparameters show that the presented transitions cover the unlicensed 60 GHz band (57-64 GHz) with good margins.
15:40 Coffee Break
16:10 Alternative Optics Design for the ALMA Band 1 Receiver (35-52 GHz)
Alvaro Gonzalez (National Astronomical Observatory of Japan, Japan); Valeria Tapia and Ricardo Finger (University of Chile, Chile); Shin'Ichiro Asayama (National Astronomical Observatory of Japan, Chile); Ted Huang (ASIAA, Taiwan)
The Atacama Millimeter/Sub-millimeter Array (ALMA) is one of the most powerful telescopes built to date. All the receivers that cover the 10 frequency bands (35-950 GHz) in ALMA must comply with stringent requirements in order to perform astronomical observations, in particular, low noise temperature and high aperture efficiency. The ALMA band 1 receiver optics (35-52 GHz) are composed of a corrugated horn antenna and a dielectric lens. They have proved difficult to design because of the large bandwidth to cover and truncation effects in cryostat apertures. This paper presents a design which meets the stringent ALMA requirements.
16:30 60-GHz CMOS On-Chip AMC Bandpass-Filtering Spiral Monopole Antenna
Huey-Ru Chuang, Wen-Yi Ruan, Chien-Chang Chou and Yi Wu (National Cheng Kung University, Taiwan)
This paper presents a 60-GHz CMOS on-chip AMC bandpass-filtering spiral monopole-antenna fabricating using TSMC 90nm CMOS technology. With the AMC structure, the radiation efficiency and power gain of the antenna increase from 6% to 11% and -9 to -6.5 dBi at 60 GHz, respectively. The measured radiation power gain is -8 dBi in the +Z direction. The filtering characteristics can be observed by the distribution of antenna power gains versus frequencies. The transmission zeros in the power gain distribution are at 45 GHz and 74 GHz, respectively. The chip size is 0.573 mm × 1.56 mm.
16:50 Coherent Fourier Optics Representation of Focal Plane Fields
Nuria LLombart (Delft University of Technology, The Netherlands); Erio Gandini (ESA - European Space Agency, The Netherlands); Beatriz Blázquez (Delft University of Technology, The Netherlands); Angelo Freni (University of Florence, Italy); Andrea Neto (Delft University of Technology, The Netherlands)
Fourier Optics is widely used to characterize the fields in the focal plane of apertures (e.g. lenses) that are large in terms of the wavelength. The applicability of this technique to focusing systems operating in the THz band is limited because of their relatively small dimensions in terms of the wavelength. In this paper, we introduce an extension of Fourier Optics that accurately characterizes the amplitude and phase of the focal fields at a large distance from the focus. This technique could be used to efficiently design focal plane arrays with a large number of off-focus elements.
17:10 Implementation of UC-EBG Structure for 60 GHz Gridded Parasitic Patch Stacked Microstrip Antenna
Alexander V Bondarik and Daniel Sjöberg (Lund University, Sweden)
A uniplanar-compact electromagnetic band-gap (UC-EBG) structure is implemented at 60 GHz on a conventional PTFE (polytetrafluoroethylene) substrate. The structure surrounds a stacked microstrip antenna with gridded parasitic patch. The UC-EBG implementation results in about 5 dB decrease in the antenna E-plane normalized radiation pattern for angles along the substrate. The measured antenna gain increase at 60 GHz is 1.5 dB. Measured results are in good agreement with simulation. The design can be used for fifth generation (5G) wireless communication systems to reduce the antenna interference with other components.
17:30 V-band Side-fed Printed Quasi-Parabolic Reflector Antenna with Beam-Steering
Alister Hosseini and Franco De Flaviis (University of California, Irvine, USA)
A design of printed V-band quasi-parabolic reflector antenna is discussed. A novel planar feeding method is proposed for this antenna which later, is used to achieve beam-steering capability. The radiation performance of the designed antenna is studied using full-wave simulations based on finite-element method.
17:50 Single-Layer Differentially-Fed Circularly Polarized Aperture Antenna for 60 GHz Applications
Bisharat J. M. Dia'aAldin (University of California San Diego, USA); Shaowei Liao (City University of Hong Kong, Hong Kong); Quan Xue (South China University of Technology, China)
This paper presents a new differentially-fed aperture antenna for circularly polarized (CP) radiation. The proposed antenna is simple in structure and is constructed on a single layer using standard printed-circuit-board (PCB) technology. Substrate integrated waveguide (SIW) is used for feeding for low transmission loss. Circular polarization is realized using a dual loop-like strips formation with travelling wave distribution as the radiating element. A cavity formed by the SIW metalized vias is adopted to enhance broadside gain. Simulation results of the antenna show a 3-dB axial ratio (AR) bandwidth of 18% (55.5–66.5 GHz), and a -10-dB impedance bandwidth of 19.5% (57–68.7 GHz). Meanwhile, the right-handed CP (RHCP) gain is stable throughout the operating bandwidth with a maximum gain of 12.3 dBi. The proposed antenna is a promising candidate for 60 GHz applications due to its merits of wideband, high efficiency, simple structure, low cost, and easy integration.

R1 Array: Array Antennas

Room: Bartolomeu Dias (Aud 4)
Chairs: Antonio Clemente (CEA-LETI Minatec, France), Giovanni Toso (European Space Agency, ESA ESTEC, The Netherlands)
13:40 On the Use of Beam-Forming Matrices for Building Overlapped Subarrays with Flat-Topped Radiation Patterns
Sergei P. Skobelev (Radiophyzika, Russia)
Comparative analysis of the subarray factor shape and sybarray architecture complexity is carried out for an approach proposed recently to building linear arrays of overlapped subarrays for limited field of view based on using beam-forming matrices. The comparisons are performed with other array architectures including arrays with the known chess board network. The issue of application of the approach to building planar arrays of overlapped subarrays is also briefly addressed.
14:00 Radon Transform: a Different Perspective on Planar Array Synthesis
Stefano Mosca (Leonardo, Italy)
In this paper the Radon transform is used to study planar arrays. It is shown that the Radon transform (in its discrete version) and the associated projection-slice theorem define interesting relations between the array factor and the amplitude coefficients of a planar array. These relations are used to develop a synthesis procedure for 2D arrays that have a pencil beam shaped array factor with the same shape (apart an angular scaling factor) on any plane through the boresight direction. With respect to previously known methods the Radon transform thus provides a different perspective, to the aforementioned planar array synthesis. The various steps of such a procedure are reported. The output of the synthesis procedure is the set of real amplitude coefficients for the array. The limitations on the applicability of the synthesis procedure are explained, and finally two examples are reported to show its application.
14:20 A Balanced-fed 45° Linearly Polarized Slot Array Antenna Using SIW Technology
Hao Zhou (Southeast University & State Key Lab. of Millimeter Waves, China); Wei Hong (Southeast University, China); Ling Tian (University of Southeast, China); Mei Jiang (Southeast University, China)
A 45° linearly polarized slot array antenna with balanced feeding network is proposed in this paper for automotive applications. The radiation element consists of one 45° inclined slot and two reflection cancellation vias. The balanced meandering feeding network proposed in this paper is able to achieve a relatively wide impedance bandwidth resulting from the traveling-wave propagation. In addition, it can obtain a wide gain bandwidth and a stable broadside radiation as the standing-wave array antennas do. A prototype array antenna with 4 radiation elements is designed and fabricated at 24 GHz. The experimental results agree well with simulation predictions. The prototype array antenna can properly work from 23.9 GHz to 25.0 GHz (4.5 %) with |S(1,1)| under -10 dB. Besides, the gain bandwidth is 23.9 GHz- 25 GHz (4.5 %) with the gain dropped by 1 dB. The maximum gain of the prototype array is 10.81 dBi at 24.7 GHz.
14:40 P-Band Antenna Array for Airborne SAR Application and DBF SAR Demonstration
Markus Limbach, Alberto Di Maria and Bernd Gabler (German Aerospace Center (DLR), Germany); Alicja Schreiber (German Aerospace Center, Germany); Ralf Horn and Rolf Scheiber (German Aerospace Center (DLR), Germany)
The Microwaves and Radar Institute at the German Aerospace Center operate an airborne multi-frequency, polarimetric, imaging SAR system. The F-SAR sensor is equipped with a variety of different antennas, based on patch technology. A new antenna is developed for the P-Band frequency range from 400 to 470 MHz, covering the Biomass mission requirements. The size and weight of the antenna array, and therefore of each single element, is reduced to a minimum. A cavity backed, capacitive coupled stacked patch element is basis for the new PII-Band antenna array.
15:00 Frequency Diverse Array with Range-Dependent Transmit Beampattern
Wen-Qin Wang (Department of Electrical and Electronic Engineering, Imperial College London); Zhi Zheng (University of Electronic Science and Technology of China, China)
Frequency diverse array (FDA) is a new antenna array concept. Different from phased-array which offers rangeindependent beampattern, FDA employs a small frequency increment across the antenna elements and yields a range-dependent beampattern. This enables the array beam to scan without the need of phase shifters or mechanical steering and provides potentials to suppress/detect range-dependent interferences/targets. This paper presents several FDA implementation issues from a top-level system description and discusses several technical challenges in transmit waveform optimization, array configuration and optimum array processing, which appeals to the array signal processing and array system engineering communities for more investigations on such a new concept.
15:20 Parallel Plate Mode Suppressed Strip-Line Fed Antenna for CP Phased Array Antenna
Youngsub Kim and Young Joong Yoon (Yonsei University, Korea (South))
A parallel plate mode (PPM) suppressed strip-line fed antenna with a via-wall is proposed for circular polarization phased array antenna system. By conducting a metal cavity using a via-wall around antenna, radiation characteristic perturbation and mutual coupling are improved. To verify the PPM suppression effects, conventional antenna, which does not via-wall, and the proposed antenna are compared in 4x4 array configuration. The reflection coefficient variation is reduced and the mutual coupling is improved about 17 dB. The measured antenna gain is 7.05 dBi, and axial ratio is 1.2 dB at designed frequency 9.5 GHz.
15:40 Coffee Break
16:10 RF MEMS Based Millimeter Wave Phased Array for Short Range Communication
Omer Bayraktar (Middle East Technical University, Turkey); Enis Kobal (University College Dublin, Ireland); Yusuf Sevinc, Çağrı Çetintepe, Ilker Comart, Kaan Demirel and Ebru Sagiroglu Topalli (Middle East Technical University, Turkey); Tayfun Akın (Middle Eastern Technical University, Turkey); Şimşek Demir and Ozlem Aydin Civi (Middle East Technical University, Turkey)
This paper presents millimeter wave phased array antenna for short range communication applications at 35 GHz. The antenna array is formed by 1 x 16 microstrip antipodal tapered slot antennas each connected to RF MEMS phase shifters for beam steering. The simulation and measurement results of the single antenna element are presented and the phase shifter structure to be used in the array is described in the paper. RF MEMS phase shifters are fabricated using an in-house surface micromachining process.
16:30 An Optically Controlled Phase Shifter for Antenna Array Beam Steering
Andre Sarker Andy (Queen Mary University of London, United Kingdom (Great Britain)); Rostyslav Dubrovka, Theo Kreouzis and Robert Donnan (Queen Mary, University of London, United Kingdom (Great Britain))
A novel optically activated phase shifter using an organic semi-conducting polymer has been developed for antenna beam steering. A blend of poly(3-hexylthiophene) (P3HT, 95%) and [6,6]-Phenyl C61 butyric acid methyl ester (PCBM, 5%) was used as a photosensitive agent to control the main beam of a prototype two-patch antenna subjected to differential illumination. The array was fabricated on FR-4 substrate, with P3HT/PCBM spray coated onto the patches to analyse the effect of illumination on the far-field response of the antenna. Return loss (S11) measurements of the antenna verified impedance matching throughout the resonant frequency shift during illumination (45mW to 1.4W). The far-field results showed 8º and 22º shifts on either side of bore-sight under differential illumination conditions. Change in light intensity between the left-illuminated and right-illuminated regions of P3HT/PCBM is the key factor behind the change in permittivity of the organic region, leading to the beam steering.
16:50 Non-uniform Printed Antenna Array for Wireless Communications in Sports Arenas
Tiago Varum and João Matos (Instituto de Telecomunicações, Universidade de Aveiro, Portugal); Pedro Pinho (IT - Instituto de Telecomunicações & ISEL - Instituto Superior de Engenharia de Lisboa, Portugal); Ricardo Abreu (Instituto de Telecomunicações)
Wireless communications had a great development in the last years and nowadays they are present everywhere, public and private, being increasingly used for different applications. Their application in the business of sports events as a means to improve the experience of the fans at the games is becoming essential, such as sharing messages and multimedia material on social networks. In the stadiums, given the high density of people, the wireless networks require very large data capacity. Hence, radio coverage employing many small sized sectors is unavoidable. In this paper, an antenna is designed to operate in the Wi-Fi 5GHz frequency band, with a directive radiation pattern suitable to this kind of applications. Furthermore, despite the large bandwidth and low losses, this antenna has been developed using low cost, off-the-shelf materials without sacrificing quality or performance, essential to mass production.
17:10 Design of High Directivity Compact Parasitic Array for Beam-Steering Applications
Abdul sattar Kaddour (Florida International University, USA); Antonio Clemente (CEA-LETI Minatec, France); Serge Bories (CEA, France); Christophe Delaveaud (CEA-LETI, France)
In this paper, two synthesis methods to design directive and compact parasitic antenna arrays with beamsteering capabilities are compared. The two methods are used to calculate the complex excitation coefficients associated to each array element needed to synthetize the antenna radiation pattern in a given direction. The analysis is principally focused on the antenna directivity and has been validated using a nine-element compact array at 1.75 GHz. The antenna is composed of nine monopoles (length 0.21λ), with only one driven element connected to a transceiver. This element is surrounded by eight parasitic monopoles arranged on a finite circular ground plane with a radius of 0.6λ and forming a circular (radius 0.1λ) array. The antenna has been prototyped and evaluated in a radio anechoic chamber. The measurement results are in excellent agreement with full-wave electromagnetic simulations.
17:30 Comparison of Phased Array Configurations of Spiral Antennas
Hongzhao Ray Fang and Ramanan Balakrishnan (National University of Singapore, Singapore); Regis Guinvarc'h (CentraleSupelec, France); Koen Mouthaan (National University of Singapore, Singapore)
A wideband spiral antenna array configuration with interstitially packed spiral antennas is presented. It is compared with a spiral array in the linear and the Wideband Array of Variable Elements Sizes (WAVES) configuration. All three configurations are realized, measured and compared. By packing smaller spiral elements in the interstices of a linear spiral array, we observe an improvement of more than 14 dB in grating lobe rejection compared to the traditional linear configuration when the main beam is pointing at boresight.
17:50 Broadband Biquad UHF Antenna Array for DOA
Rainer Mueller and Ralf Lorch (Hensoldt Sensors GmbH, Germany)
In this paper a broadband biquad antenna array for DOA applications is investigated. Measurements of the single broadband biquad antenna element and simulation results of antenna array arrangements for vertical polarisation, horizontal polarisation or polarisation independent direction of arrival estimation are shown.

Monday, April 13 13:40 - 15:40 (Europe/Berlin)

S1 AlphaSat: Alpha-Sat Experiment

Room: Tristão V Teixeira (Pav 5A)
Chairs: Antonio Martellucci (European Space Agency, The Netherlands), Armando Rocha (University of Aveiro & Instituto de Telecomunicações, Portugal)
13:40 Alphasat Q/V-band Propagation Campaign Preparation in Aveiro
Armando Rocha and Flávio M. da Silva Jorge (Instituto de Telecomunicações); João Lima and António Soares (Universidade de Aveiro, Portugal)
We briefly describe the developments of a propagation receiver for the Alphasat Q-band copolar beacon that is expected to be operational from March 2015. The receiver link budget and the expected attenuation dynamic range are presented. The receiver RF hardware and a simplified approach to one axis only antenna pointing system solution is described. The already developed Python beacon detector software, based on a Ettus Research Card, is introduced with details about the used copolar detection algorithm and other possible ones.
14:00 The Ka- And Q-band AlphaSat Ground Station in Vigo
This paper presents the ongoing work for developing a Ka- and Q-band satellite beacon receiving station at the University of Vigo. The ground station has been developed in order to join the Alphasat Aldo Paraboni propagation experiment. This new European measurement campaing will be possible thanks to the Alphasat Aldo Paraboni payload, which has been supported by the Italian Space Agency (ASI) as contribution to the Alphasat project that is executed by the European Space Agency (ESA) in the framework of the ARTES 8 Telecom programme. The objective of this campaign is the simultaneous acquisition of Ka- and Q-band propagation measurements in several receiving stations in Europe. This contribution describes the Vigo ground station for the Alphasat Aldo Paraboni propagation experiment, analyzes its specifications and presents the first measurements and results.
14:20 A DVB-S2 Signal Analyzer for the Alphasat TDP5 Communication Experiment
Harald Schlemmer (Joanneum Research, Austria); Eral Tuerkyilmaz (JOANNEUM RESEARCH Forschungsgesellschaft mbH, Austria); Michael Schmidt (Researcher & Joanneum Research, Austria); Wilfried Gappmair (Graz University of Technology, Austria); Juan J. Rivera Castro (European Space Agency, The Netherlands)
During the design phase of the Q/V-band ground station in Graz/Austria for the Alphasat TDP5 adaptive coding and modulation (ACM) communication experiment, which is based on the DVB-S2 standard, a tool for accurate SNR measurements with high time resolution was needed. State of the art DVB-S2 demodulators with built-in SNR estimators did not satisfy the requirements because the algorithms were not available or they could not be changed. On the other hand, the query times were not predictable. These facts lead to the decision to implement a DVB-S2 signal analyzer on a GNU Radio software defined radio (SDR) platform, which is able to provide channel state information on a per frame basis. In the current paper, the detailed architecture of the signal analyzer is presented together with simulation and measurement results for different DA and NDA SNR estimators.
14:40 AlphaSat Ka-band and Q-band Receiving Station in Rome: Development, Status and Measurements
Augusto Marziani (Telespazio S.p.A. & Sapienza University of Rome, Italy); Fernando Consalvi (FUB, Italy); Simone Chicarella (Sapienza University of Rome, Italy); Elio Restuccia (ISCOM, Italy); Luigi Amaduzzi and Frank S. Marzano (Sapienza University of Rome, Italy)
A Ka-band (20 GHz) and Q-band (40 GHz) receiving station, located in Rome (Italy), has been designed and implemented for AlphaSat satellite Technology Demonstrator Payload 5 "Aldo Paraboni". Ka-band station is complete and preliminary measurements are shown. Mechanical tracking has been implemented a will be installed soon. Q-band station is being assembled and should be tested in early 2015. A laboratory characterization of all blocks and subsystems has been carried out and is briefly described. The design and implementation of a W-band microwave radiometer is also on going, whereas Ka- and W-band beacon data will be combined with measurements from a meteorological station, raingauge and disdrometer
15:00 Alphasat Propagation Experiment in Madrid: Quality Assessment of the Measurements
Jose M Riera (Universidad Politécnica de Madrid, Spain); Gustavo Siles (Universidad Privada Boliviana, Bolivia); Pedro Garcia-del-Pino (Universidad Politecnica de Madrid, Spain); Ana Benarroch (Universidad Politécnica de Madrid, Spain)
Universidad Politécnica de Madrid (UPM) is participating in the Alphasat propagation experiment by measuring the copolar level of the Q-Band beacon at 39.4 GHz. Measurements started in test mode in December 2013 and are being carried out continuously since April 2014. In this paper the quality of the measurements is assessed with regards to the receiver performance and several systematic effects. The experiment layout is presented in the first place. Then, different effects are discussed in detail.
15:20 Rain XPD of Alphasat TDP5 Propagation Signals: Preliminary Analyses and Disdrometer Derivations
Karin Plimon, Félix Cuervo, Guenter Lammer, Guenther Obertaxer and Michael Schönhuber (Joanneum Research, Austria); Juan J. Rivera Castro (European Space Agency, The Netherlands)
To assess the possibilities for polarization frequency reuse in SatCom applications, the behavior of the satellite channel is to be understood and studied. An experimental setup in Graz / Austria is used to compare XPD measurements of an Alphasat Ground Propagation Terminal in Q-band with disdrometer-derived values. It is shown, that theoretical expectations for the XPD measurements are basically met. The case of a rain event is discussed with quantitative comparisons. Refined investigations are planned for the future, including wide spread rain cases with atmospheric parameters (rain height) clearly determined. Further measurements are planned for the future with statistical XPD analysis, as an input to polarization frequency reuse considerations.

S4 Multibeam: Multi-beam satellites

Room: Paulo da Gama (Pav 5B)
Chairs: Cecilia Cappellin (TICRA, Denmark), Enrico Reiche (Airbus Defence and Space GmbH, Germany)
13:40 Design of a Push-Broom Multi-Beam Radiometer for Future Ocean Observations
Cecilia Cappellin, Knud Pontoppidan and Per Nielsen (TICRA, Denmark); Niels Skou and Sten Søbjærg (Technical University of Denmark, Denmark); Alexander Ihle (HPS GMBH, Germany); Marianna Ivashina and Oleg Iupikov (Chalmers University of Technology, Sweden); Kees van 't Klooster (Eindhoven University of Technology, The Netherlands)
The design of a push-broom multi-beam radiometer for future ocean observations is described. Such a radiometer has the big advantage of being fully stationary on the platform and provides a sensitivity one order of magnitude higher than a traditional conical scanning radiometer. Thanks to a dense focal plane array and a dedicated optimization procedure, the radiometric performance can be optimized and the instrument can accurately measure in C, X and Ku band and as close as 15 km from the coast line.
14:00 An Optimal Beamforming Algorithm for Phased-Array Antennas Used in Multi-Beam Spaceborne Radiometers
Oleg Iupikov and Marianna Ivashina (Chalmers University of Technology, Sweden); Knud Pontoppidan, Per Nielsen and Cecilia Cappellin (TICRA, Denmark); Niels Skou and Sten Søbjærg (Technical University of Denmark, Denmark); Alexander Ihle (HPS GMBH, Germany); Dennis Hartmann (HPS-GmbH, Germany); Kees van 't Klooster (Eindhoven University of Technology, The Netherlands)
Based on the oceanography requirements for future spaceborne multi-beam radiometers equipped with phased array feed (PAF) systems, we propose an optimal beamforming algorithm which yields high beam efficiency over a wide observation region - while minimizing the side-lobe and cross-polarization power - and leads to a relatively simple array and beamformer design. Such systems hold promise to achieve much higher resolution and sensitivity than that of the present day feed systems, and will be able to operate within as close as 5-15 km from the coast where the brightness temperature of land areas is much higher than the brightness temperature of the sea. The proposed algorithm is demonstrated for a numerical example of the PAF system feeding a torus reflector antenna at Ku-band.
14:20 Wide-Band Compact Antenna Feed for Multi-Beam Satellite Communications
Carlos A. Leal-Sevillano (TRYO Aerospace, Spain); Jorge A Ruiz-Cruz (Universidad Autonoma de Madrid & Escuela Politecnica Superior, Spain); Jose Ramon Montejo-Garai and Jesus Maria Rebollar (Universidad Politecnica de Madrid, Spain)
This paper presents the design of a wide-band compact antenna feed for dual-band single circular polarization. The feed chain system is based on a recently proposed configuration that uses a diplexer and a bi-phase polarizer conveniently joined with a single mode waveguide. This solution leads to compact lowcost feed designs well suited for multi-beam antennas with a single feed per beam in the context of satellite communications. A new design with enhanced performance is presented with simulated results of axial ratio below 0.2 dB across 18.2-20.2 GHz and 28- 30 GHz. Moreover, the impact of the finite return loss of the high efficiency horn is studied and a compensated high-performance feed is presented.
14:40 Dual-band (Tx/Rx) Multiple-Beam Reflector Antenna Using a Frequency Selective Sub-Reflector for Ka-band Applications
Nelson Fonseca (European Space Agency, The Netherlands)
This paper describes a dual-reflector antenna geometry combining multiple-feed-per-beam feed systems and a dichroic sub-reflector to produce a full dual-band (Tx/Rx) multiple beam coverage as typically required for broadband satellite missions. The proposed antenna configuration has several advantages as it requires only one main reflector aperture to produce the full coverage and makes use of two single band (Tx and Rx) multiple-feed-per-beam feed systems that are scaled versions of each other. Preliminary results are presented at antenna level assuming perfect dichroic screen and feed systems. These results confirm the potential of the proposed configuration for missions having strong satellite accommodation constraints and requiring a relatively small number of beams (typically less than 50 beams). This could particularly be of interest on board of small platforms or for secondary payloads. The dichroic sub-reflector being the critical point in this configuration, a preliminary feasibility study is also included, providing promising results.
15:00 Space Qualification of K/Ka-Band Single Feed Per Beam Feed Chains
Enrico Reiche (Airbus Defence and Space GmbH, Germany); Christian Hartwanger, Un Pyo Hong and Ralf Gehring (Airbus DS GmbH); Helmut Wolf (Airbus Defence and Space & Communications Satellites, Germany)
In this paper we report on design and qualification of two types of compact dual circularly polarised K/Ka-band feed chains for multi-spot single feed per beam applications. The presented feed products were developed to engineering qualification model (EQM) standard in the frame of ESA ARTES 3-4 and can be applied for user beam as well as gateway communication. Additionally one type of feed chain provides radio frequency (RF) sensing capability for an automatic tracking system enabling a more accurate antenna pointing. Qualification test results just as a comparison of predicted and measured performance will be shown.
15:20 A Compact Planar Feed Structure for Ka-Band Satcom-on-the-Move Tracking Antennas
Hendrik Bayer, Alexander Krauss and Ralf Stephan (Technische Universität Ilmenau, Germany); Matthias Hein (Ilmenau University of Technology, Germany)
The increasing interest in bi-directional mobile high data rate satellite communications in Ka-band necessitates the development of dedicated antenna tracking systems and feeds. In this paper we describe a compact feed structure for a mobile satellite communications ground terminal with a Cassegrain reflector antenna realised on a printed circuit board. The novel structure provides a dual circular polarisation communication mode as well as the TM01 mode for multimode monopulse tracking. This coupler, based on carefully matched transitions from grounded coplanar lines to circular waveguides, is operational at 20GHz and 30 GHz, to cover the downlink and the uplink frequency ranges in Ka-band. This work contributes to the development of a satellite terminal for land-mobile communications in disaster scenarios.

Monday, April 13 13:40 - 18:10 (Europe/Berlin)

W4 PropSim: Propagation Modelling and Simulation

Propagation/Wireless Networks
Room: Afonso de Albuquerque (Pav 3B)
Chairs: Cesar Briso (Universidad Politecnica de Madrid & ETSIS Telecomunicacion, Spain), Enrico M. Vitucci (University of Bologna, Italy)
13:40 Benefits of Variation of Large Scale Fading Across Large Antenna Arrays
Jocelyn Aulin (Huawei Technologies Sweden AB, Sweden)
Massive MIMO antenna arrays are being studied for 5G due to their ability to focus energy to desired receiver, reducing interference to other users, giving rise to higher spectral and energy efficiencies [1]. Conventional analysis assumes that the large scale fading component of the channel model is constant across the entire Massive MIMO antenna array. However, when the number of Massive MIMO antennas is divided among remote antenna sites, each site experiences independent small and large scale fading. Massive MIMO channel measurements show that large scale fading is not constant but varies across a large antenna array [3]. In this paper, a closed-form expression for the downlink received SIR is derived to evaluate cell spectral efficiency, assuming that large scale fading varies across an antenna array. Higher cell spectral efficiency results for a downlink multi-user MIMO system is obtained for a new channel model compared with the conventional channel model.
14:00 Performance of Receiver Spatial Diversity in Peer to Peer Radio Communications Within Vegetation Media
Iñigo Cuiñas and José Antonio Gay-Fernández (University of Vigo, Spain); Javier López-Pérez and Diego Pascual (Universidade de Vigo, Spain)
Forests are typical scenarios for rescue and emergency actions, in which peer-to-peer radio communication systems emerge as good solutions to maintain the crewmembers connected and to coordinate the complete operation. Implanting spatial diversity at reception improves the connectivity in such situations, as explained along this contribution supported by measurement results at 2.4, 3.5 and 5.8 GHz. The proposal of an extended radio propagation model for peer-to-peer communications in vegetation media is the aim of this contribution, which also evaluates the gain obtained by spatial diversity. The canopy shape seems to have more influence than the species or the season. However, all tested scenarios provide gain in the radio propagation link, which reinforces the idea presented in this contribution.
14:20 Simple Approximation of Power Azimuth Spectrum for Multipath Propagation Environment
Cezary Ziółkowski, Jan M. Kelner, Leszek Nowosielski and Marian Wnuk (Military University of Technology, Poland)
This paper presents simple approximation of the power azimuth spectrum (PAS) that can extend the capabilities of propagation models used in simulation studies for multipath propagation environment. Described angular distribution of power is the first presented analytical form that maps PAS based on the transmission characteristics of the environment. Close-form expression describes three main subset components: delay components, locally scattered components and direct path component. Thus, presented PAS model is called the delayed and local components model (DLCM). The statistical properties of received signals and multi-elliptical propagation model are used to define individual components of analytical form for this model. Results for DLCM are compared with other models as well as with experimental results available for different propagation scenarios. Comparative analysis shows very close agreement of developed model with experimental data and also better fit compared to the existing PAS models.
14:40 Evaluation and Proposal on Modified Model for 3GPP Based Indoor Penetration Loss Model
Kentaro Nishimori and Hayate Kimoto (Niigata University, Japan); Tetsuro Imai and Ngochao Tran (NTT DOCOMO, INC., Japan)
In this paper, experimental evaluation for indoor penetration loss is employed, in order to evaluate the severe interference environment such as the interference between different cells by Heterogeneous networks. The measured results are compared with 3GPP model. It is shown that 3GPP model is not proper when considering the interference near the window inside the room via measurement results. Moreover, we propose a new model for the indoor penetration loss which realizes an accurate estimation even if the interference station is located near the window.
15:00 MIMO Dual Polarized Fixed Satellite Systems Above 10GHz Above: Channel Modeling and Outage Capacity Evaluation
Charilaos Kourogiorgas (Science and Technology Facilities Council\RAL Space, United Kingdom (Great Britain)); Athanasios D. Panagopoulos (National Technical University of Athens, Greece); Pantelis-Daniel Arapoglou (European Space Agency, The Netherlands); Stavros Stavrou (Open University of Cyprus, Cyprus)
In this paper, a channel model for dual polarization satellite systems at Ka-band is proposed using multi-dimensional Stochastic Differential Equations (SDEs). Moreover, this channel model is employed for the calculation of the outage capacity statistics of MIMO dual-polarized fixed satellite systems above 10GHz, using multiplexing technique. Some significant conclusions are drawn.
15:20 Broadband Radio Communications in Subway Stations and Tunnels
Cesar Briso (Universidad Politecnica de Madrid & ETSIS Telecomunicacion, Spain); Ke Guan (Beijing Jiaotong University, China); Lei Zhang (Donghua University, China); Jean Fernandez (Universidad Politecnica de Madrid, Spain)
Broadband communications are very important for train control systems and passengers services. Now 4G LTE is being deployed for commercial use and it is necessary to deploy this system also in a complex subway environment with tunnels, stations and many complex structures that affect propagation. For this reason it has been measured and modeled broadband propagation in railway environment. The paper presents broadband measurements made with a channel sounder at 900 and 2400 in subway tunnels. These measurements have provide detailed information of the propagation and have been used to make a broadband propagation model.
15:40 Coffee Break
16:10 A Monte-Carlo Approach to Modeling Radio Propagation by Ray-Tracing
Jan Barowski, Bastian Meiners and Ilona Rolfes (Ruhr-Universität Bochum, Germany)
In this paper a Monte-Carlo approach to modeling the propagation behavior of electromagnetic waves by ray-tracing is described. Since the approximation of specular reflections does not hold, if the considered wavelength is in the same regime as the surface roughness, more sophisticated reflection and transmission models have to be taken into account. In order to achieve a Monte-Carlo integration over all field contributions, the angle of departure, the complex field amplitude, and the polarization at the point of interaction are stochastically generated using the scattered farfield as a 2D probability density function. The resulting field strength at the receiver is given by the superposition of all scattered waves and can be formulated in terms of an integral equation.
16:30 Joint Ray Launching Method for Outdoor to Indoor Propagation Prediction Based on Interpolation
Bing Xia (University of Sheffield, United Kingdom (Great Britain)); Zhihua Lai (Ranplan Wireless Network Design Ltd, University of Sheffield, United Kingdom (Great Britain)); Guillaume Villemaud (Université de Lyon, INRIA, INSA-Lyon, CITI, France); Jie Zhang (University of Sheffield, Dept. of Electronic and Electrical Engineering, United Kingdom (Great Britain))
This paper proposes a novel model for predicting the outdoor to indoor radio signal coverage. This model is based on a joint ray launching algorithm that adapts different resolutions for outdoor and indoor simulations. The performance of the joint ray launching method is evaluated by a measurement at 3.5 GHz frequency. This model appears to be efficient for a scenario with mixed resolutions, in terms of both accuracy and computational cost.
16:50 WBAN Off-Body Channel Angular Structure Comparison Between SAGE Estimation and Ray Tracing Simulation
Nicolas Amiot (Université Rennes I & Institut d' Electronique et de Télécommunications de Rennes, France); Meriem Mhedhbi (Orange Labs, France); Bernard Uguen (University of Rennes I, France); Raffaele D'Errico (CEA, LETI, Minatec Campus & Univ\. Grenoble-Alpes, France)
In this paper, we present a comparison between Off-Body channel characteristics estimated with Space-Alternating Generalized Expectation-Maximization (SAGE) algorithm from measurement data and those obtained from ray-tracing simulated data. Measurement data were obtained considering a body-worn antenna on a phantom and an external one simulating an access point. The chosen simulation approach relies on taking into account the influence of the body directly into the antenna radiation pattern, and not by including a dedicated body representation into the simulated environment. This simplified approach provides a good agreement between simulation and measurement in terms of received power and Angle of Arrival retrieval.
17:10 Ray Tracing Simulations of Indoor Channel Spatial Correlation for Physical Layer Security
Enrico M. Vitucci (University of Bologna, Italy); Francesco Mani (EURECOM, France); Taghrid Mazloum (Telecom ParisTech, France); Alain Sibille (Telecom Paris, France); Vittorio Degli-Esposti (University of Bologna, Italy)
A 3D Ray-Tracing software, including diffuse scattering, is employed to simulate spatial correlations in an indoor environment at the frequency of 5GHz. Measurements, performed with a Vector Network Analyzer, are used to validate simulated results. The goal is to establish the accuracy of ray-based simulations to model a Physical Layer Security scenario, where two legitimate users try to take advantage of the intrinsic properties of the wireless channel to generate a shared secret key inaccessible to an eavesdropper.
17:30 Propagation Model Based on Building Penetration Loss Measurement for TVWS System
Tomoshige Kan and Hirokazu Sawada (National Institute of Information and Communications Technology, Japan); Jun-ichi Takada (Tokyo Institute of Technology, Japan)
For the coexistence management between primary and secondary users in TV white space, a simple propagation model for short range transmission and low antenna height is needed. This is crucial to define the interference risk area to primary user from secondary user. For estimating the area, measurements of building penetration loss for wooden and small size light-gauge steel houses have been conducted at UHF band. A propagation model based on free space loss with additional building passage losses is proposed. The model is useful to estimate the TVWS secondary user area of short-range transmission and low antenna height in the area that has a mixture of large and small buildings. The models of the building penetration loss for the two types of buildings are compared.
17:50 Incoherent Scattering of Normal Modes in Urban Canyon: Theory and Measurements
Dmitry Chizhik (Nokia Bell Labs, USA); Michael MacDonald (Bell Labs, Lucent Technologies, USA); Reinaldo Valenzuela (Bell Laboratories, Alcatel-Lucent)
Standard theory of normal mode propagation in a LOS street scenario is extended to include incoherent mode scattering. The addition leads to reduced null depth in predicted locally-averaged path gain consistent with measurements. Resulting predictions show close agreement with measured signal strength. Unlike empirical models, the full 3D field model provides such angular effects as the reduction in angle spread with distance, with all orders of reflection implicitly included.

Monday, April 13 13:40 - 15:40 (Europe/Berlin)

W5 IndoorProp: Indoor Propagation

Propagation/Wireless Networks
Room: João G Zarco (Pav 3C)
Chairs: Conor Brennan (Dublin City University, Ireland), Fono Vincent (Université du Québec en Outaouais, Canada)
13:40 Advanced Indoor Localisation Based on the Viterbi Algorithm and Semantic Data
Jens Trogh (Ghent University, Belgium); David Plets (Ghent University); Luc Martens (Ghent University, Belgium); Wout Joseph (Ghent University/IMEC, Belgium)
In this work an indoor localisation system based on the Viterbi algorithm is developed. In addition to this Viterbi principle, two other factors are taken into account: the environment of the object that is being traced and an adjustable maximum speed. This semantic data is used to further improve the accuracy. The developed algorithm was verified by simulations and experimentally using a real-life test case. The results indicate a significant improvement in accuracy and standard deviation.
14:00 Investigation on the Geometric Properties of Multipath Components in Indoor Radio Channels
Bastian Meiners, Jan Barowski, Artur Nalobin and Ilona Rolfes (Ruhr-Universität Bochum, Germany)
This contribution deals with a new approach of a channel impulse response interpolation algorithm. The algorithm is used for simulations of channel impulse responses within a stochastic radio channel simulator. For this purpose, investigations on the behavior of multi path components during a motion of a transmitter and a receiver are shown. The new approach is described and a detailed analysis of the required parameters by using a ray-tracing model is given.
14:20 Power Delay Profile Analysis and Modeling of Industrial Indoor Channels
Yun Ai and Michael Cheffena (Norwegian University of Science and Technology, Norway); Qihao Li (University of Oslo, Norway)
In this paper, power delay profile (PDP) measurements of three different industrial indoor environments are presented. The measurements were performed in the frequency range of 0.8 to 2.7 GHz using a vector network analyzer (VNA) and the virtual antenna array method. Dense multi-path scattering with multi-path components arriving in clusters were observed. This is due to the abundance of highly reflective scatterers present in measured industrial environments. The measurement results revealed two different shapes of the PDP, neither of which fully fit the well known Saleh-Valenzuela (S-V) model or power-law model. Thus, modifications were made on the conventional S-V model and power-law model to better represent the measurements. Furthermore, Weibull distribution was found to fit the measured small-scale fading.
14:40 Electromagnetic Wave Propagation Modeling in a Complex Environment Using Uniform Geometrical Theory of Diffraction
Fono Vincent (Université du Québec en Outaouais, Canada); Larbi Talbi (University of Quebec - Outaouais, Canada); Khelifa Hettak (Communications Research Centre, Canada)
This paper is based on modeling the propagation mechanism in confined complex environment at narrowband frequency. The environment chosen is located at ground floor of one of the university buildings. The narrowband channel measurements are realized at 10GHz and compared to the proposed model developed in Matlab software. The proposed model is based on combination of ray-tracing algorithm with uniform geometric theory of diffraction (UTD). Additionally, using wireless Insite software, the wideband channel parameters are derived and compared to the proposed analytical model.
15:00 Radio Frequency Measurements and Capacity Analysis for Industrial Indoor Environments
Yun Ai and Michael Cheffena (Norwegian University of Science and Technology, Norway); Qihao Li (University of Oslo, Norway)
In this study, path-loss and shadowing measurement results for three different industrial indoor environments at 900, 1600, and 2450 MHz are presented. The results show that the one-slope model fits well the measured path-loss, and the shadow fading samples follow a zero-mean Normal distribution. Low path-loss exponent values were found from our measurements which may suggest the presence of heavy multi-path propagation in the channel. A comprehensive review of reported path-loss and shadowing measurements from various industrial environments is presented and compared with our measurement results. In addition, a channel capacity model with dependence on the measured parameters is investigated, which gives an insight to the effect of the propagation channel on system performance. This may allow service providers in evaluating the technical feasibility of industrial wireless communications.
15:20 A Method of Moments Based Indoor Propagation Model
Ian Kavanagh, Vinh Pham-Xuan, Marissa Condon and Conor Brennan (Dublin City University, Ireland)
This paper presents initial efforts to develop a full-wave propagation model for indoor electromagnetic wave propagation based on the Volume Electric Field Integral Equation (VEFIE). A form of the V-EFIE is chosen which facilitates the use of the FFT to expedite the iterative solution. Although the formulation requires the discretisation of the entire volume, only unknowns placed in the scattering material (walls etc) contribute to the scattered field. Consequently, the unknowns placed in free space can be effectively removed from the updated process in each iteration leading to rapid convergence. Results are presented documenting the computational efficiencies and simple path loss models are created from the full-wave simulations which are in accordance with those reported in the literature.

WS2 RFID: Chipless RFID Future and Challenges

Scientific Workshop
Diogo de Silves (Room 1.08)
Chair: Mohamed El Hadidy (FOM University of Applied Science & CST-Middle East, Germany)
13:40 A Novel Collision Avoidance MAC Protocol for Multi-Tag UWB Chipless RFID Systems Based on Notch Position Modulation
Mohamed El Hadidy (FOM University of Applied Science & CST-Middle East, Germany); Ahmed El-Awamry (University of Duisburg-Essen, Germany); Abdelfattah Fawky (University of Duisburg Essen, Germany); Maher Khaliel and Thomas Kaiser (Universität Duisburg-Essen, Germany)
In this work, a novel Notch Position Modulation (NPM) scheme is presented as the first Medium Access Control (MAC) algorithm for handling the multi-tag identification scenario of the frequency signature based chipless RFID tags. This NPM algorithm reduces the sensing and identification time and accordingly the overall system latency. Furthermore, an advanced UWB signaling scheme based on frequency sweeping criteria is designed for the RFID reader in order to make the best use of FCC UWB regulations for increasing the reading range. This protocol provides MAC identity for each chipless RFID tag, enables determining the number of the existing tags, orthogonal modulated signatures for each tag and the corresponding modulation parameters. Moreover, the mitigation of the interference between the several chipless RFID tags and the undesired environmental reflections is a straightforward result of this new protocol.
14:20 Printable Depolarizing Chipless RFID Tag Based on DGS Resonators for Suppressing the Clutter Effects
Maher Khaliel (Universität Duisburg-Essen, Germany); Mohamed El Hadidy (FOM University of Applied Science & CST-Middle East, Germany); Thomas Kaiser (Universität Duisburg-Essen, Germany)
In this paper, a novel Frequency Coded depolarizing chipless RFID tag is introduced. The uniplanar printable, symmetrical and easily coded tag consists of L-shape Defected Ground Structure (DGS) resonators defining the tag signature and two orthogonally polarized UWB monopole antennas for realizing the cross-polarization retransmission process. The number of notches could be easily increased by adding parallel resonators preserving the same tag size. The polarization diversity is utilized to reduce the mutual coupling, suppress the channel clutter effects and efficiently detecting the tag on metallic platforms. An 8-bits code tag prototype from 3.1 GHz to 6.1 GHz is presented and the maximum readable number of notches will be investigated. The UWB monopole antenna and the DGS resonators simulation, implementation and measurement are separately demonstrated. The manufactured chipless RFID tag operation is verified in indoor real-world environment and will be illustrated in the full paper.
15:00 Smart Notch Detection Techniques for Robust Frequency Coded Chipless RFID Systems
Ahmed El-Awamry (University of Duisburg-Essen, Germany); Abdelfattah Fawky (University of Duisburg Essen, Germany); Mohamed El Hadidy (FOM University of Applied Science & CST-Middle East, Germany); Thomas Kaiser (Universität Duisburg-Essen, Germany)
The main objective of this work is to introduce two adaptive window-based notch detection techniques for UWB Frequency Coded chipless RFID system. The first proposed algorithm is the Window Based Singular Value Decomposition (WBSVD), where various frequency dependent patterns of the notch are used as a training sequence for pre-defined bandwidth (window) to create an orthonormal basis functions. The WBSVD accurately and rapidly detects the notch based on the minimum distant vector criteria. In the second algorithm, Adaptive Energy Detection, an adaptive threshold is estimated for each window depending on the Probability of false alarm considering the frequency selective channel. Simulation results show that both algorithms are immune to environmental effects such as cluttering, fading and multipath components. Moreover, the two algorithms operated efficiently regardless on the type of chipless tags. A comprehensive comparison and the trade-offs between the two techniques would be illustrated at the end.

Monday, April 13 16:10 - 18:10 (Europe/Berlin)

C29 BAN: [C] Measurements and Simulations in Channel Modelling in Wireless Body Area Networks

Room: Pedro A Cabral (Aud 2)
Chairs: Sławomir J. Ambroziak (Gdańsk University of Technology, Poland), Carla Oliveira (University of Lisbon, Instituto Superior Tecnico & INOV - INESC, Portugal)
16:10 Miniaturized UWB Implantable Antenna for Brain-Machine-Interface
Kamya Yekeh Yazdandoost (International Iberian Nanotechnology Laboratory, Portugal & University of Oulu, Finland); Ryu Miura (NICT, Japan)
Brain-Machine-Interface (BMI) will transfer the neural activities of brain to machine for potential actions. Antenna for BMI needs to be very small, due to limited available space in human head. Ultra Wideband technology with their low cost, low power consumption, high data rate and small form factor of antenna is one of the strong candidate for medical implanted devices. Possibility to have a miniature antenna and as a result small implanted device, put the UWB system on the top for the BMI application. This paper presents the design of a very small UWB antenna which is placed in the skull bone and covered with head tissues, i.e. fat and skin. Tissue electrical properties around the implanted antenna has significant effect on the antenna performance, thus, electrical properties of tissues were considered on the time of antenna design.
16:30 Realistic Performance Measurement for Body-Centric Spatial Modulation Links
Patrick Van Torre, Thijs Castel and Hendrik Rogier (Ghent University, Belgium)
Spatial Modulation is a new transmission mode which increases spectral efficiency by employing information-driven transmit antenna selection. This performance is realized at a reduced hardware complexity and cost because only a single radio-frequency transmit chain is necessary. A measurement campaign is performed to assess the characteristics of spatial modulation for body-centric communication, transmitting from a walking person with front and back textile antennas integrated into garment, towards a base-station in realistic conditions. In the transmitted frames, additional spatial multiplexing as well as space-time coded data blocks are included. The off-body communication link is analyzed for line-of-sight as well as non line-of-sight radio propagation, comparing the characteristics of the different transmission modes under equal propagation conditions as well as at an equal channel capacity of 2 bit/s/Hz.
16:50 Angular Characteristics of the UWB On-to-Off-Body Channel in Indoor Scenarios
Oudomsack Pierre Pasquero (Orange Labs, Rennes, France); Raffaele D'Errico (CEA, LETI, Minatec Campus & Univ\. Grenoble-Alpes, France)
In this paper, we present a channel measurement campaign in indoor environment aiming the characterization of the angular properties of the channel in the presence of the human body. Measurements were performed by using isolated UWB antenna and body-mounted antenna on different positions. Multipath components are estimated by means of SAGE algorithm. From these estimations, clusters are detected and characterized in the delay and angular domains.
17:10 Geometric Modeling of Shadowing Rate for Off-body Propagation During Human Walking
Takahiro Aoyagi (Tokyo Institute of Technology, Japan); Minseok Kim (Niigata University, Japan); Jun-ichi Takada (Tokyo Institute of Technology, Japan)
In this paper, shadowings caused by human body during walking in on-off body propagation are geometrically calculated. The calculated shadowing characteristics are given by binary status of shadowings. These shadowing characteristics are modeled by using closed formula to make these information useful for evaluating BAN communication qualities.
17:30 Simplified Human Phantoms for Wireless Body Area Network Modelling
Lukasz Januszkiewicz (Lodz University of Technology, Institute of Electronics, Poland); Slawomir Hausman (Lodz University of Technology, Poland)
In the paper simplified human body phantoms that can be used for modeling of wireless body area networks are presented. Proposed models approximate the human body with PCV pipes filled with tap water. Due to their simplicity, proposed physical models can be easily reproduced in any laboratory with a low cost. These models also have easy to prepare numerical versions. It is shown that simplified model can be successfully used in numerical simulations of wireless body area networks as well as in measurements.
17:50 Scenario-based WBAN Channel Characterization in Various Indoor Premises
Christophe Roblin (LTCI, TELECOM ParisTech and CNRS); Yunfei Wei (TELECOM ParisTech, France)
The influence of the surrounding environment on the characteristics of the UWB WBAN (Wireless Body Area Network) channel is considered in this article, focussing on the contribution of the Dense Multipath Component (DMC).

C35 ModeBase: [C] Mode-based strategy for antenna analysis and design

Antennas/Multi Applications
Room: Gil Eanes (Aud 3)
Chairs: Dirk Manteuffel (University of Hannover, Germany), Qi Wu (Beihang University, China)
16:10 Rigorous Eigenmode Analysis of Conducting Sphere
Qi Wu (Beihang University, China)
this paper presents a rigorous method to obtain the eigenmodes of canonical conducting objects. The inner-product definition is used and the dyadic Green's function is expanded by vector wave functions. The expressions for the eigenvalues and normalized eigencurrents of a circular sphere are revisited and used as a benchmark. Numerical errors due to the high-frequency and low-frequency limitations are briefly discussed.
16:30 Radiation Pattern Adjustment of A Double Notched Antenna by Using Characteristic Modes Analysis
Shen Wang and Hiroyuki Arai (Yokohama National University, Japan)
Radiation pattern adjustment of a double notched antenna is discussed in this paper to show a way of applying characteristic modes analysis for antenna parameter optimization. In this example, radiation pattern of the antenna is adjusted to omni-directional type and bi-directional type, respectively, by changing responses of two different characteristic modes of the antenna.
16:50 Optimal Placement of PCB-integrated Diversity Elements in a Compact Tunable Handset Antenna
Robert Martens (University of Kiel, Germany); Dirk Manteuffel (University of Hannover, Germany)
This paper investigates the optimal placement of diversity elements integrated on the printed circuit board (PCB) of a compact mobile terminal. The main antenna of the terminal is based on a capacitive coupling element (CCE) which is frequency reconfigurable through an adaptive impedance tuning circuit. Characteristic mode analysis is used to find optimal locations for two PCB-integrated diversity elements. The goal is to place the diversity antennas on the PCB in such a way that the mutual coupling between the antenna ports is minimized within the frequency bands. It is found out that those capacitive fed diversity elements at maxima of the PCB current distribution yield favorable performance in terms of electromagnetic (EM) isolation between the antennas. The concept is verified with EM simulated examples in two E-UTRA operation bands 2 and 7 (1.9GHz and 2.6GHz).
17:10 Antenna Design Via Current Control of Antenna Currents Using Theory of Characteristic Modes
Ezdeen Elghannai (The Ohio State University, USA); Roberto G. Rojas (MIT-Lincoln Laboratory & The Ohio State University, USA)
An approach for designing antennas using the concept of current control and reactive loading is presented. This scheme is based on a modal analysis referred to as Characteristic Modes (CM) which is used to obtain physical insight about the antenna's behavior and to modify/improve the antenna's currents to achieve the desired goals. The scheme could be applied to obtain wideband impedance and radiation pattern behavior; however, the reactive loads may exhibit a non-foster behavior which requires active devices. If the wideband condition is relaxed, the technique can be applied to design multiband antennas for various applications where the loads can be foster (lumped elements). The technique was applied to a Universal Serial Bus (USB) and Radio Frequency Identification (RFID) antennas and yielded a much improved antenna perfor
17:30 Isosceles Right Triangular Waveguides with Boundary Conditions of Composite Electric and Magnetic Walls
Jing Yang, Lian Liu and Cheng Jin (Beijing Institute of Technology, China)
Isosceles right triangular waveguides with six kinds of boundary conditions of composite electric and magnetic walls are discussed in this paper. The completed closed-form modal solutions are derived for both transverse electric and transverse magnetic modes. These exact solutions not only serve as accuracy standards for approximate methods, but also solve a fundamental problem. Their corresponding electric field distributions are plotted for the dominant modes of the six kinds of isosceles right triangular waveguides. Finally, electric field distributions excited in the quarter-mode substrate integrated waveguide and eighth-mode substrate integrated waveguide are studied, and they are in good agreement with theoretical predictions.
17:50 Study of Dipole Antennas' Characteristic Modes Through the Antenna Current Green's Function and the Singularity Expansion Method
Francois Sarrazin (University of Paris-Est-Marne-la-Vallée & ESYCOM, France); Said Mikki (University of New Haven, USA); Yahia Antar (Royal Military College of Canada, Canada); Philippe Pouliguen (DGA/Direction de la Stratégie, France); Ala Sharaiha (Université de Rennes 1 & IETR, France)
This paper deals with modelling the Antenna Current Green's Function (ACGF) using the Singularity Expansion Method (SEM). The ACGF is the exact transfer function of an antenna in the spatial domain and is able to deal with both near and far fields. In order to study the spectral content of the ACGF, the authors suggest here applying the SEM on the ACGF to extract its poles (characteristic modes). This work focuses on poles selection and the modeling accuracy.

C37 Mutual: [C] Mutual Coupling Formulation and its Effects in Antenna Systems

Antennas/Cellular Communications
Room: Pêro Escobar (Pav 3A)
Chairs: Yahia Antar (Royal Military College of Canada, Canada), Said Mikki (University of New Haven, USA)
16:10 Aspects of Generalized Electromagnetic Energy Exchange in Antenna Systems: A New Approach to Mutual Coupling
Said Mikki (University of New Haven, USA); Yahia Antar (Royal Military College of Canada, Canada)
We attempt the construction of a general theory of electromagnetic interactions that takes into account the classic problem of mutual coupling encountered in the analysis and design of electromagnetic systems both in theory and practice.
16:30 Study of Mutual Coupling for Patch Antennas with Single-Layer Capacitive Feed and Its Application to Fabry-Pérot Arrays
Adrian Capristan (University Carlos III of Madrid, Spain); Darwin Blanco (Ericsson, Sweden); Eva Rajo-Iglesias (University Carlos III of Madrid, Spain)
The use of Fabry-Perot antennas in thinned phased arrays is more and more common as the simplicity for achieving high directive basic elements is a major advantage. This work proposes the study of Fabry-Perot arrays made using totally planar technology (not even with grounded vias) based on the use of patch antennas with single-layer capacitive feed as feeding elements. This version of patch antennas are known to be wideband and planar. Mutual coupling will be studied both for these patches as regular array elements and also in Fabry-Perot application where the results will be compared to the use of waveguide apertures as feeds in terms of bandwidth (it is expected that the bandwidth limitation comes from the Fabry-Perot structure and not from the feed) and mutual coupling.
16:50 Analysis of Mutual Coupling in Large Arrays of Printed Antennas Using Contour-FFT
Shambhu Nath Jha (Thales Belgium SA, Belgium); Simon Hubert (Université Catholique de Louvain & ICTEAM Institute, Belgium); Christophe Craeye (Université Catholique de Louvain, Belgium)
An efficient mutual coupling analysis method is presented for large arrays of printed antennas. Mutual coupling effects play an important role when one deals with large arrays, as the near-field and far-field characteristics of an individual element get drastically altered in such condition. These effects are characterised through the embedded element patterns and through the port currents when a single element is excited while all the other elements in the array are terminated with matched loads. We demonstrate that, with the help of the Contour-FFT approach combined with the MBF-based-multipole approach for homogeneous medium, the mutual coupling effects can be accurately analyzed with Nlog2N complexity for substrate related interactions. Several results are presented and an excellent comparison is reported between the results obtained with the fast method and with the reference solutions.
17:10 The Simple Truth About Effects of Mutual Coupling in MIMO Arrays for Single and Multiple Bit Streams in Rich Isotropic Multipath
Per-Simon Kildal (Chalmers University of Technology, Sweden); Xiaoming Chen (Xi'an Jiaotong University, China)
In this paper, we demonstrate the effects of mutual coupling on embedded radiation efficiency, correlation, diversity gain, and MIMO efficiency for single and multiple bit streams in rich isotropic multipath (RIMP) environment by using parallel dipoles and a compact wideband four-port antenna as examples.
17:30 Wideband Decoupling and Tunable Matching Networks for Multi-Port Antennas
Montaha Bouezzeddine (Ford & Germany, Germany); Werner L. Schroeder (RheinMain University of Applied Sciences, Germany)
Cognitive radio is a very promising technology but it poses many challenges for the antenna system design. Apart from bandwidth limitations of small antennas, additional requirements emerge from the goal to replace conventional, frequency duplexers by tunable filters and high dynamic range RF front ends. In this paper, we present a systematic design procedure for matching and decoupling multi-port antennas with a focus of achieving the highest possible isolation between antenna ports. An important aspect of the approach is the introduction of pre-matching circuitry between the antenna and the decoupling network. The novelty resides in the wide frequency range over which the decoupling network is applicable in connection with low complexity electrical tuning circuitry.
17:50 On the Constrains to Isolation Improvement in Multi-Antenna Systems
Sathya Narayana Venkatasubramanian (Ericsson AB, Sweden); Anu Lehtovuori (Aalto University, Finland); Clemens Icheln (Aalto University & School of Electrical Engineering, Finland); Katsuyuki Haneda (Aalto University, Finland)
Different techniques are feasible to improve the antenna isolation between closely spaced antennas, especially for compact devices, which includes the use of lumped element networks between the feed points of the antennas. This paper systematically analyzes the achievable isolation between two closely spaced dipole antennas using a lumped element cancellation network. The improvement in antenna isolation is studied using a combination of resistive and reactive elements between the antennas and compared with using only reactive elements with phase shifting transmission lines. Design curves which propose optimal spacing between antennas with lumped element networks for improved isolation are also provided. The results show better wideband isolation improvement than using only reactive elements together with phase shifting transmission lines, at the cost of using a lossy element.

C43 PropSat: [C] Results of Ka and Q band propagation campaigns using Alphasat Aldo Paraboni and other Satellites

Room: Tristão V Teixeira (Pav 5A)
Chairs: Laurent Castanet (ONERA, France), Antonio Martellucci (European Space Agency, The Netherlands)
16:10 The Aldo Paraboni Scientific Experiment: Ka/Q Band Receiver Station in Hungary
László Csurgai-Horváth, István Rieger and József Kertész (Budapest University of Technology and Economics, Hungary)
The Aldo Paraboni payload is the Ka/Q-band propagation experiment of the Alphasat satellite. In this paper we introduce the receiver station in Budapest, Hungary. After the system description the first time series of measured received signal will be shown. For the first months of operation a preliminary attenuation distribution is also presented. Because the receiver operates without a tracking system, we propose a new algorithm to compensate the small-scale diurnal signal level variation caused by the apparent satellite movement.
16:30 Three-Site Ka-Band Diversity Experiment Performed in Slovenia and Austria
Andrej Vilhar, Gorazd Kandus, Arsim Kelmendi and Urban Kuhar (Jozef Stefan Institute, Slovenia); Andrej Hrovat (Jožef Stefan Institute, Slovenia); Michael Schönhuber (Joanneum Research, Austria)
The paper describes an ongoing site-diversity experiment performed in central Slovenia and southern Austria. Three synchronized Ka-band satellite beacon receivers of the same type have been used for this purpose. Two of them are installed in Slovenia, measuring a 20.2 GHz beacon from ASTRA 3B. The third receiver is located in Graz, Austria, measuring a 19.7 GHz beacon signal from Alphasat. The measured attenuation time series are statistically analyzed for each of the three single sites, the three pairs of the sites and the combination of all three sites. The results show the gain obtained as a result of site-diversity and, in case of combinations with Graz station, partially also as a result of satellite-diversity. Finally, the results are compared also to the existing ITU-R models.
16:50 Propagation Experiments At 20 GHz in Southern Europe to Test High Order Propagation Models
Laurent Castanet and Xavier Boulanger (ONERA, France); Carlo Riva (Politecnico di Milano, Italy); Franz Teschl (Joanneum Research, now with Graz University of Technology); Jose M Riera (Universidad Politécnica de Madrid, Spain); Armando Rocha (University of Aveiro & Instituto de Telecomunicações, Portugal)
This paper deals with the prediction of high order and conditional statistics to be used for the design of High Throughput Satellite systems at Ka and Q/V bands. The validation of this type of prediction methods is discussed in terms of the amount of measurements required to get statistical reliability and new propagation experiments carried out at 20 GHz in Portugal, Spain and France with Eutelsat Ka-Sat and Astra-3B beacons are addressed for the test of these high order propagation models.
17:10 Earth-Space Propagation Data Processing for Ka-band Frequencies and Above
Danielle Vanhoenacker-Janvier (Université catholique de Louvain, Belgium); Xavier Boulanger and Laurent Castanet (ONERA, France); Alberto Graziani (European Space Agency, The Netherlands); Carlos Pereira (Spacebel, Belgium)
The purpose of this paper is to propose pre-processing and processing procedures for the calculation of the degradations due to the troposphere on Earth-space links from measured beacon data. The need for accurate measurements, processed in a uniform way by the various experimenters, has increased due to the use of Ka-band and above. This paper presents various pre-processing and processing techniques enabling the extraction of the tropospheric effects from the measured beacon, in the presence of various ancillary ground equipment.
17:30 Use of Microwave Profiler and Ka/Q-band Ground Propagation Terminal for Alphasat ALDO TDP5 Propagation Experiment – First Year of Operation
Félix Cuervo, Karin Plimon and Michael Schönhuber (Joanneum Research, Austria); Vinia Mattioli (He-Space Operations & Sapienza University of Rome, Italy); Antonio Martellucci and Juan J. Rivera Castro (European Space Agency, The Netherlands)
In order to study propagation effects for future satellite communication frequencies, the Alphasat Aldo Paraboni (TDP 5) payload includes two beacon transmitters at Ka-band (19.701 GHz) and Q-band (39.402 GHz). Under ESA contract a Ground Propagation Terminal was developed to measure the co- and the cross polar signals of both frequencies with the same antenna. The measurement site hosts ancillary equipment to measure the weather and atmospheric situation, including a meteorological station, a disdrometer and an Atmospheric Propagation and Profiling System (ATPROP): a highly stable microwave radiometer system to assess radio propagation in the spectral range from 10 to 90 GHz. This paper reports on the brightness temperature and propagation measurements carried out in Graz (Austria) since November 2013, the data validation of the instruments and the prediction of the existing ITU-R propagation models.
17:50 Preliminary Statistics From the NASA Alphasat Beacon Receiver in Milan, Italy
James Nessel and Michael Zemba (NASA, USA); Jacquelynne Houts (NASA Glenn Research Center, USA); Lorenzo Luini and Carlo Riva (Politecnico di Milano, Italy)
NASA Glenn Research Center (GRC) and the Politecnico di Milano (POLIMI) have initiated a joint propagation campaign within the framework of the Alphasat propagation experiment to characterize rain attenuation, scintillation, and gaseous absorption effects of the atmosphere in the 40 GHz band. NASA GRC has developed and installed a K/Q-band (20/40 GHz) beacon receiver at the POLIMI campus in Milan, Italy, which receives the 20/40 GHz signals broadcast from the Alphasat Aldo Paraboni TDP#5 beacon payload. The primary goal of these measurements is to develop a physical model to improve predictions of communications systems performance within the Q-band. Herein, we provide an overview of the design and data calibration procedure, and present preliminary statistics of the NASA propagation terminal, which has been installed and operating in Milan since May 2014. The receiver has demonstrated a dynamic range of 40 dB at an 8-Hz sampling rate.

DS1 Beamform: Beamforming and signal processing

Antennas/Defense and Secutity
Room: João G Zarco (Pav 3C)
Chairs: Michael Jensen (Brigham Young University, USA), Ioannis Kyriakides (University of Nicosia Research Foundation, Cyprus)
16:10 Polarisation-Angle-Delay Estimation for Blind Localisation Approaches Under Multipath Propagation
Stephan Häfner (Technische Universität Ilmenau, Germany); Martin Käske and Reiner S. Thomä (Ilmenau University of Technology, Germany)
A new method to estimate the polarisation, anglesof- arrival and delay of multiple waves impinging at an antenna array is presented. The method is developed for blind localisation approaches of a single transmitter under multipath propagation. Therefore, no knowledge about the transmitter and a SIMO radio channel is assumed. Based on cross relations between the receiver channels, a cost function is derived, which have to be optimised for parameter estimation purposes. A method to estimate the number of impinging waves is also presented. The overall estimator is validated with test measurements.
16:30 Angle of Arrival Estimation for Moving User Equipment with Application to Indoor Terahertz Communications Using Grid Based Bayesian Filter
Bile Peng (TU Braunschweig, Germany); Sebastian Priebe, Sebastian Rey and Thomas Kürner (Technische Universität Braunschweig, Germany)
The phased arrays provide a high antenna gain and can be applied to the future indoor Terahertz (THz) communications to compensate for the high path loss, which, however, requires a precise estimate of the signal arrival direction. This paper presents a method for the signal arrival direction estimate in cases when the user equipment is moving in the wireless network coverage area. The method uses the grid based Bayesian filter to estimate the signal arrival direction recursively from the previous estimate and the current measurement. The simulation result shows that this method achieves a high and stable antenna gain while the user equipment is moving with low computational effort.
16:50 Tracking More Targets with Less Antenna: An Investigation Into the Co-array Concept
Jiachen Wang (KU Leuven, Belgium); Hantao Xu and Xuezhi Zheng (Katholieke Universiteit Leuven, Belgium); Guy Vandenbosch (Katholieke Universiteit Leuven (KU Leuven), Belgium)
In this paper, two multiple compressive DoA estimation algorithms are investigated, namely the sparse ruler, and the coprime sampling array. These algorithms explore the eigen matrix structure of a non-uniform linear array in order to artificially synthesize a larger uniform linear array, in this way boosting the capability of a DoA tracking system beyond the theoretical limit of the number of sources that can be detected with a certain number of antenna elements. In other words, we can detect the Direction of Arrival (DoA) of more sources with less antenna elements. Crucial is that the study is based on real measurements conducted on a real demonstrator platform. The key parameters that affect the DoA estimation are investigated. The results show clearly that the sparse ruler algorithm has a better performance.
17:10 Localization of Multiple Unknown RF Sources by Combining a Power Monitoring Network and a Guided Moving Sensor Under Constraints
Ioannis Kyriakides (University of Nicosia Research Foundation); Konstantinos Gotsis (Aristotle University of Thessaloniki, Greece); John Sahalos (Aristotle University of Thessaloniki, GR, Thessaloniki, Greece & University of Nicosia, CY, Nicosia, Cyprus)
The authors propose a Sequential Monte Carlo (SMC) method for the localization of an unknown number of RF sources with unknown transmit power, using Received Signal Strength (RSS) measurements of a network of static sensors and a guided moving sensor. A constraint is imposed on the number of trips that the moving sensor is allowed to make. The SMC algorithm incorporates an adaptive RSS threshold detection method that improves the detection of sources of varying transmission power. Simulations demonstrate the performance of the proposed algorithm, under the constraints of various numbers of sensor trips and static sensors.
17:30 Compact Beam Forming Network of a Switched Phased Array
Vincent Jaeck (French-German Research Institute of Saint-Louis, France); Loic Bernard (ISL, France); Kouroch Mahdjoubi (Université de Rennes, France); Ronan Sauleau and Sylvain Collardey (University of Rennes 1, France); Philippe Pouliguen (DGA/Direction de la Stratégie, France); Patrick Potier (DGA/Maîtrise de l'Information, France)
We propose here a compact beam forming network developed for a switched beam antenna array printed on a conical projectile fuze. Due to tight space constraints, the beam former is made of multiple stacked PCB layers; it is designed around 5.2GHz to excite a 12-element antenna array printed on a 155mm projectile. The numerical results demonstrate very attractive performance.
17:50 Optimal Array Signaling for Key Establishment in Static Multipath Channels
Rashid Mehmood (Wavetronix LLC, USA); Jon Wallace (Lafayette College, USA); Michael Jensen (Brigham Young University, USA)
The broadcast nature of wireless transmission leaves the communication vulnerable to a wide variety of attacks that can compromise security. Generally, data security is ensured by encrypting the communication between the participating nodes using a secret encryption key. One relatively recent proposal for establishing these keys is to employ common randomness available in the wireless channel. This paper extends prior work on key establishment using adaptive arrays for static LOS channels to the case of static multipath channels. The optimization procedure maximizes the secure key generation rate for the worst-case position of an eavesdropper.

MA3 PrintElem: Printed elements, baluns and associated circuits

Antennas/Multi Applications
Room: Paulo da Gama (Pav 5B)
Chairs: Paola Pirinoli (Politecnico di Torino, Italy), Hao Xin (University of Arizona, USA)
16:10 Square-shape Fully Printed Chipless RFID Tag and Its Applications in Evacuation Procedures
Diego Betancourt (TU Dresden, Germany); Raji Sasidharan Nair (Technische Universität Dresden, Germany); Katherina Haase, Georg Schmidt, Maxi Bellmann, Daniel Höft and Arved Hübler (TU Chemnitz, Germany); Frank Ellinger (Technische Universität Dresden, Germany)
Herein, square-shaped chipless RFID tags are reported. Thereby, the development of the design, the applied fabrication process and the experimental verification are described. The designed tags, which are based on Frequency Selective Surfaces, are produced by screen printing on flexible PET and paper substrates and are considered suitable for the fabrication by means of roll-to-roll printing technologies. The functionality is proved by both, the measurements inside and outside the anechoic chamber. In order to corroborate the tag's independence to the position feature, the tags are further measured for several rotation and tilt angles. During measurements in the anechoic chamber, a reading distance up to 1.8 m could be demonstrated. Furthermore, a new optimized methodology for semi-automatic measurements that reduces the time per measured tag is introduced. Moreover, for the first time a chipless RFID tag to be applied in evacuation procedures under crisis events is proposed.
16:30 A Novel Design of Miniaturized Power Divider and Branch Coupler Using Interdigital Circuit
Bin Li (Chinese Academy of Space Technology, Xi'an, China)
This paper presents a novel design to reduce the size of both power dividers and branch couplers using interdigital circuit. The disadvantage of planer dividers and couplers working at low frequency is their large size. To overcome it, a design method by using interdigital circuit is proposed, which consists of two interdigital capacitors and a high characteristic impedance line. The design theory is explained using an equivalent circuit model, and the equation of the theory is presented in details. One 2.4GHz Wilkinson divider based on FR4 substrate and one 1.4GHz branch coupler based on RO4003C substrate using the interdigital circuit are simulated, fabricated and measured. The results show that a size reduction of about 40% is achieved with good performance.
16:50 Efficient Probe Excitation of Dielectric Image Line Using Substrate Integrated Waveguide Based Matching Network
Chandra Prasad (Indian Institute of Technology, Kanpur, India); Soumava Mukherjee (Indian Institute of Technology Jodhpur, India); Animesh Biswas (IIT Kanpur, India)
In this paper, a novel transition from co-axial probe to substrate integrated waveguide (SIW) and from SIW to dielectric image line (DIL) is proposed in Ku-band (12-18 GHz). The proposed transition is designed on a single substrate and thus eliminates complex multi-layer fabrication process for implementation of dielectric image line. Simulation results obtained using HFSS shows wide relative bandwidth. For probe to SIW back-to-back transition, the relative bandwidth (-20dB) is 38.5% and for back-to-back transition from probe to SIW and from SIW to DIL. The relative bandwidth (-15dB) is 24.5%. The insertion loss is better than 3.2 dB throughout the operating bandwidth.
17:10 New Compact Design for Short Range Wireless Power Transmission At 1GHz Using H-Slot Resonators
Sherif Sayed Ahmed Salah Hekal (Egypt-Japan University of Science and Technology & Faculty of Engineering at Shoubra - Benha University, Egypt); Adel Bedair (Egypt-Japan University of Science and Technology, Egypt)
In this paper, we present a new design for short range wireless power transfer using two compact H-slot resonators. These quasi-lumped element resonators can transfer power through electromagnetic resonant coupling with high efficiency and compact structures. The proposed design enables us to achieve efficiency about 85% for power transmission at distance 5 mm between the two resonators. For verification of the new design theory, we have fabricated and measured the proposed WPT system to operate at 1 GHz. Measured results have shown a close agreement with simulation responses and theoretical studies.
17:30 Hybridization Strategy for Microstrip Antenna Optimization
Linh Ho Manh (Hanoi University of Science and Technology, Vietnam); Marco Mussetta (Politecnico di Milano, Italy); Paola Pirinoli (Politecnico di Torino, Italy); Riccardo Enrico Zich (Politecnico di Milano, Italy)
Thanks to the exploding growth of radio mobile and wireless communication applications, microstrip antenna with its advantages of low cost and flexible fabrications, emerges as the most suitable candidate. However, direct antenna synthesis by full-wave analysis are computationally expensive in time and memory usage. Considering the problem of optimizing antenna as a system of uncertainty, when each set of geometrical parameters returns a totally different response. In order to achieve solutions with practicability, robustness and low cost functions, the recent trends tend to involve evolutionary algorithms and bio-inspired computation. In this article, the hybridization technique between Particle Swarm Optimization (PSO) and Artificial Neural Network (ANN)is implemented to optimize a dual-annular ring proximity coupled feed antenna.
17:50 Miniaturization of Microwave Components and Antennas Using 3D Manufacturing
Jonathon O'Brien, Maria Cordoba Erazo and Eduardo Rojas (University of South Florida, USA); Juan D. Castro (ANSYS, Inc. & University of South Florida, USA); Mohamed M Abdin, Jing Wang and Gokhan Mumcu (University of South Florida, USA); Kenneth Church (nScrypt, Inc & Sciperio, Inc, USA); Paul Deffenabugh (Sciperio, Inc., USA); Thomas Weller (Oregon State University, USA)
3D multi-material additive manufacturing has promising potential to improve the performance and form factor of microwave and electromagnetic components. The ability to design and produce truly 3D form factors can lead to smaller volume and better performing antennas, allow the combining of different materials to optimize and reduce the weight of distributed circuit designs, and cost effectively produce structural electronic systems. Along with these new capabilities come increased needs for material choices, innovative methods for materials characterization, and changes in the CAD tools that are used for design. These challenges, along with examples of 3D RF design with additive manufacturing are given in this paper.

Monday, April 13 19:00 - 20:00 (Europe/Berlin)

Welcome Reception

Room: Museu de Marinha

Tuesday, April 14

Tuesday, April 14 9:00 - 10:40 (Europe/Berlin)

Bi5 PropBio: Propagation in Biomedical Environments

Room: Bartolomeu Dias (Aud 4)
Chairs: Andrea Ruaro (Technical University of Denmark, USA), Alain Sibille (Telecom Paris, France)
9:00 Exposure Assessment of Stray Electromagnetic Fields Generated by a Wireless Power Transfer System
Rosanna Pinto (Technical Unit of Radiation Biology and Human Health, ENEA); Manuele Bertoluzzo (Department of Industrial Engineering, University of Padova); Vanni Lopresto (Technical Unit of Radiation Biology and Human Health, ENEA); Sergio Mancini (Technical Unit of Radiation Biology and Human Health); Caterina Merla (Technical Unit of Radiation Biology and Human Health, ENEA); Giovanni Pede and Antonino Genovese (Technical Unit for Advanced Technologies for Energy and Industry, ENEA); Giuseppe Buja (Department of Industrial Engineering, University of Padova)
The wireless power transfer technology represents a promising application in contactless electric vehicle battery charging systems. A bench prototype, delivering a power of 560 W at 85 kHz, suitable for charging the batteries of a city car, was designed and realized. Equal transmitting and receiving resonant coils, equipped with ferrite cores, were realized in a spiral configuration. The single coil and the coupled system were experimentally characterized in terms of inductance and mutual inductance for dimensioning the resonance capacitor of the circuit. Moreover, measurements of the stray electromagnetic fields (EMFs) emitted by the prototype were performed, in order to assess the exposure levels at which workers, operating in proximity of the bench prototype, will be subjected. Results evidenced that both measured electric (E) and induction magnetic (B) fields were compliant with the European Directive 2013/35/EU, in which minimum health and safety requirements regarding the EMFs exposure of workers are established.
9:20 Simulation of Microwave Transmission Measurements of the Human Heart
Marcel Seguin, Jeremie Bourqui and Elise Fear (University of Calgary, Canada); Michal Okoniewski (University of Calgary & Acceleware Ltd, Canada)
An alternative hemodynamic monitoring technology based on ultrawideband (UWB) microwave transmission measurements using a state-of-the-art near field sensor is explored. Simulations were performed from 1.5 GHz to 3.5 GHz to assess the system sensitivity and attenuation in anatomically accurate human phantoms. Results show a correlation between changes in the dielectric properties (DPs) of the heart and the transmission signal. Multipath and leakage effects are observed in measurements. High attenuation is a limitation of the proposed technology.
9:40 Analysis of Dependence of Signal Propagation Loss on Poses in Intra-Body Communication
Ibuki Yokota (Kyoto Institute of Technology, Japan); Yuichi Kado (Kyoto Institute of Technology & Graduate School of Science and Technology, Japan); Masaki Ishida (Kyoto Institute of Technology, Japan)
Near-field coupling communication (NFCC) is a technology that uses the surface area of the human body as a communication path using the megahertz band. We have already evaluated the basic mechanism connected with NFCC on a phantom that was electrically regarded as a human body. The shape of the human body was not considered in the evaluation since the shape of the phantom was simply rectangular and parallel piped. However, it is important to evaluate what effects the body shape has on the signal loss to enable practical use. We evaluated signal loss characteristics according to positions and poses of the human body. The experimental results revealed that signal loss on the human body was dependent on these positions and poses. We propose appropriate positions for where the wearable transceiver is worn on the body to ensure reliable communication with any poses.
10:00 On the Applicability of Pathloss Model to Predict RF Human Exposure
Sandra Gomez (Télécom Bretagne, France); Patrice Pajusco (IMT Atlantique, France); Christian Person (Télécom Bretagne)
An experimental setup for measuring the electric field distribution in indoor environment is presented. Measurements are performed with an isotropic electric field probe and compared with a classical dipole antenna. Results are used to evaluate performances and applicability of usual engineering pathloss models in the prediction of human exposure to electromagnetic fields.
10:20 Analysis of Electric Field Spatial Variability in Simulations of Electromagnetic Waves Exposure to Mobile Telephony Base Stations
Mame Lo-Ndiaye (Centre Scientifique et Technique du Bâtiment); Nicolas Noé (Centre Scientifique et Technique du Bâtiment, France); Pierre Combeau (XLIM University of Poitiers, France); Yannis Pousset (Université de Poitiers & XLIM, France); François Gaudaire (Centre Scientifique et Technique du Bâtiment, France)
This paper focuses on the study of electric field spatial variability in the context of mobile telephony base stations exposure. Electric field is computed using a UTD simulation technique suitable for large urban areas. Two complementary approaches of spatial variability are proposed here. One based upon spatial autocorrelation and the other one on statistical laws identification to account for electric field distribution in an urban area. The first approach allows us to quantify the spatial dependency of electric field in three representative areas of exposure. The second one demonstrates that statistical laws depending of the area type and urban typology can represent the electric field behavior.

Tuesday, April 14 9:00 - 12:50 (Europe/Berlin)

C10 60GHz: [C] Antenna technologies for fixed wireless access at 60 GHz and above

Antennas/High Data-rate Transfer
Room: Gonçalo V Cabral (Pav 5C)
Chairs: Jiro Hirokawa (Tokyo Institute of Technology, Japan), Per-Simon Kildal (Chalmers University of Technology, Sweden)
9:00 60 GHz Slot Antenna Array Based on Ridge Gap Waveguide Technology Enhanced with Dielectric Superstrate
Hussein Attia (King Fahd University of Petroleum and Minerals (KFUPM), Saudi Arabia); Milad Sharifi Sorkherizi and Ahmed Kishk (Concordia University, Canada)
A 2 × 2 planar slot antenna array is design at 60 GHz. The slots are excited by a printed a corporative feeding network based on the ridge gap waveguide (RGW). Such a network, requires more than a full wavelength spacing between the slots, which cause excitation of undesired grating lobes. In order to reduce the grating lobes level, a low-cost dielectric superstrate at a distance of half wavelength in the air above the slot antenna array is used. The presence of the superstrate is acting as a planar lens that increased the slot array gain by 6 dB along the broadside direction as well as greatly reduced the grating lobes level. The single element and the array characteristics are provided.
9:20 A Self-Supported Hat-Fed Reflector Antenna for 60 GHz Frequency Band
Alireza Motevasselian (LEAX Arkivator Telecom, Sweden); Tomas Östling (Arkivator AB, Sweden)
A compact hat-fed self supported reflector antenna for V band operation is presented. The antenna exhibits a high gain with low reflection coefficient. A semi-spherical shell radome of Polycarbonate material has been used. The simulation results show that radiation patterns comply ETSI class 2 standard.
9:40 60-GHz Multi-layer Multi-beam Slotted Waveguide Array Made by Diffusion Bonding Technique
Karim Tekkouk (Tokyo Institute of Technology, Japan); Ronan Sauleau (University of Rennes 1, France); Mauro Ettorre (University of Rennes 1 & UMR CNRS 6164, France); Makoto Sano (Toshiba Corporation, Japan); Makoto Ando (Tokyo Institute of Technology, Japan)
A novel multi-beam antenna based on a 4-way Butler matrix with side lobe level control is proposed in the 60-GHz band. The side lobe level is controlled using a dedicated circuit. This dual-layer antenna is made by hollow waveguides and is assembled using diffusion bonding technique. The radiating part is a compact array of ridged waveguides designed to avoid appearance of grating lobes in the visible range for large scanning angles. The antenna field of view is ± 43° with side lobes lower than -17.5dB over the entire scanning range. The reflection bandwidth for VSWR <2 is larger than 7%. At the design frequency, the measured conductor losses of the antenna are estimated lower than 0.64 dB for all ports.
10:00 Designs of Plate-laminated Waveguide Slot Array Antennas for 60GHz and Above
Jiro Hirokawa (Tokyo Institute of Technology, Japan); Satoshi Ito (KDDI Research, Inc., Japan); Tatsuya Yamamoto (Tokyo Institute of Technology, Japan); Miao Zhang (Xiamen University, China); Makoto Ando (Tokyo Institute of Technology, Japan)
This paper presents two designs of the plate-laminated waveguide slot array antenna. One is a design for 12x16 elements. It is for the number of elements other than a power of two, by introducing a crossing junction and an asymmetric T-junction in the feed waveguide. The other is a wideband design of a circularly-polarized antenna to cover 57-66GHz fully. The radiating part is designed by genetic algorithm together with fast analysis by the method of moments.
10:20 Analysis of Large Planar 60 GHz Array Including Microstrip-Ridge Gap Waveguide Distribution Network Using Modular Approach
Esperanza Alfonso (Gapwaves AB, Gothenburg, Sweden); Seyed Ali Razavi (Graduate University of Advanced Technology, Kerman, Iran); Liangliang Xiang (Huawei, Shanghai, China); Haiguang Chen (Huawei Technologies Sweden AB, Gothenburg, Sweden)
A planar 32x32 element array antenna at 60 GHz including microstrip-ridge gap waveguide distribution network is analyzed using modular approach. This approach gives a fast estimation of the return loss of a large array including the corporate distribution network, and allows for an improvement of the return loss by tuning the length of the branches of the power dividers in the corporate network.
10:40 Coffee Break
11:10 120-GHz-band Wireless Link Antenna Technologies for Polarization Multiplexing
Akihiko Hirata (Chiba Institute of Technology, Japan); Jun Takeuchi (NTT Corporation, Japan)
Polarization multiplexing is an effective way to double the data rate of a 120-GHz-band wireless link. This paper presents 120-GHz-band antenna technologies for polarization multiplexing and describes a 120-GHz-band wireless link system that can transmit over-20-Gbit/s data, such as uncompressed 8K videos.
11:30 A New 2x2 Microstrip Patch Sub-array for 60GHz Wideband Planar Antenna with Ridge Gap Waveguide Distribution Layer
Ashraf Uz Zaman and Per-Simon Kildal (Chalmers University of Technology, Sweden)
We propose a two layer planar antenna where a ridge gap waveguide corporate distribution network feeds a subarray of 2×2 radiating microstrip patch elements. There exists a coupling slot in the ground plane of the substrate layer which allows the excitation of the microstrip patch elements from the ridge gap waveguide layer. The ground plane of the substrate also serves the purpose of top metal layer for the ridge gap waveguide section. The proposed antenna is operating over 15% relative bandwidth covering 56-66 GHz frequency range with -12 dB reflection coefficient. The simulated directivity of the 2×2 slot array is 11.5dbi at the center of the band.
11:50 Active Reconfigurable Luneburg Lens At 60GHz
Olivier Lafond (IETR, France); Mohamed Himdi (Université de Rennes 1, France); Jonathan Bor (IETR - University of Rennes 1, France); Hervé Merlet and Philippe Le Bars (Canon CRF, France)
An active receiver antenna with beam scanning and beam shaping capability is described. This antenna is based on a plate inhomogeneous Luneburg lens fed by several waveguide sources. Firstly, a plate Luneburg lens is manufactured thru a new technological process allowing to change the refractive index of a single foam layer. The measured radiation patterns of this lens are compared with simulated ones at 60GHz. Secondly, the active antenna is detailed and measured radiation patterns demonstrate the beam reconfigurability of this antenna system.
12:10 Deployment Considerations for 60 GHz Backhaul Using Smart Street Furniture
Lars Manholm (Ericsson Research, Sweden); Jonas Fridén and Bengt-Erik Olsson (Ericsson AB, Sweden)
Deploying backhaul in smart street furniture, such as light poles, billboards or information kiosks, sets new requirements and constraints as compared to traditional line of sight deployment. The problems of antenna alignment in non-line-of-sight conditions, suitable antennas for automatic alignment and the added complexity of an outer enclosure are discussed.
12:30 A Study of Interference Canceller for DDD System on Millimeter-Wave Band Fixed Wireless Access System
Kazuya Kojima, Toru Taniguchi, Masatoshi Nagayasu and Yasuhiro Toriyama (Japan Radio Co., Ltd., Japan); Miao Zhang (Xiamen University, China)
Our efforts are being made to implement a high speed and high frequency utilization efficiency mm-wave band backhaul system for the purpose of applying it to the 5G mobile networks. We propose a fixed wireless access (FWA) system of full duplex radio communication (called the Directional Division Duplex (DDD) system) capable of simultaneous bidirectional communication of the same radio frequency channel and same polarization, which has been achieved by a combination between dual antenna with high spatial isolation and interference canceller for suppressing the interference signals back-flowing from transmission to its own reception.

C30 MiMed1: [C] Methodologies and modelling for EMF in medical diagnostics and therapy (MiMed)

Room: Pedro A Cabral (Aud 2)
Chairs: Lorenzo Crocco (CNR - National Research Council of Italy, Italy), Panagiotis Kosmas (King's College London, United Kingdom (Great Britain))
9:00 Volume Integral Equation Formulation for Medical Applications
Mina Bjelogrlic (HUG, Switzerland); Michael Mattes (Technical University of Denmark, Denmark); Ioannis D Koufogiannis (Huber+Suhner AG, Switzerland); Santiago Capdevila (SWISSto12, Switzerland); Juan R Mosig (Ecole Polytechnique Federale de Lausanne, Switzerland)
In recent years, there is a considerable and growing interest in developing fast integral equation methods for solving Maxwell's equations. Volume integral equations are a versatile technique to model inhomogeneous scattering objects. Numerical tests show excellent convergence properties of the technique for strongly inhomogeneous media with high dielectric contrast.
9:20 A Unidirectional Wideband Printed Quasi-Yagi Antenna for Microwave Breast Imaging
Constantine G. Kakoyiannis (Institute of Communication and Computer Systems, National Technical University of Athens); Irene Karanasiou (Hellenic Military University, Greece); Maria Koutsoupidou (Institute of Communication and Computer Systems, National Technical University of Athens); Nikolaos Uzunoglu (School of Electrical and Computer Engineering, National Technical University of Athens)
Active microwave imaging is a promising medical modality for breast cancer detection, and is mainly implemented via ultra-wideband (UWB) microwave imaging and microwave tomography. Regardless of technique, the spearhead of any microwave imaging system is an array of antennas, which illuminate the target and collect the scattered energy. The antenna element is expected to be compact, wideband, efficient and high-gain, ideally focusing all radiated energy inside the target. This paper describes a printed quasi-Yagi antenna, which features a unidirectional driver-reflector pair and two closely-spaced directors. The directors increase the operating bandwidth (BW) significantly while maintaining a broadband front-to-back ratio (FBR) above 10 dB. The antenna operates in the 2.0-3.3 GHz range (55% fractional BW), and exhibits a maximum gain of 5 +/- 0.5 dBi and high efficiency. The architecture of the antenna is inherently simple and its impedance BW is practically unaffected by the presence of the breast phantom.
9:40 Non-Invasive Microwave Lung Water Monitoring: Feasibility Study
Jochen Moll (Goethe University Frankfurt am Main, Germany); Jan Vrba (Faculty of Biomedical Engineering, Czech Technical University in Prague, Czech Republic); Ilja Merunka (Czech Technical University in Prague & Faculty of Electrical Engineering, Czech Republic); Ondrej Fiser, Jr. (Czech Technical University in Prague & Faculty of Biomedical Engineering, Czech Republic); Viktor Krozer (Goethe University of Frankfurt am Main, Germany)
In this paper, a numerical feasibility study is performed for the non-invasive microwave monitoring of lung water by patients with pulmonary edema. The microwave sensor considered here is the balanced antipodal Vivaldi antenna working in the frequency range from 1,5 to 6,5 GHz. A numerical phantom is a MRI-based high-resolution anatomical model of a patient. In the numerical phantom lung water volume has been successively varied form 0 to 900 ml and the phantom has been virtually exposed to an electromagnetic Gaussian pulse. Reflected signals were subsequently used for estimation of the lung water level and the obtained estimated values have shown a relative error of less than 6%.
10:00 Initial Study for Detection of Multiple Lymph Nodes in the Axillary Region Using Microwave Imaging
Raquel C. Conceição (Instituto de Biofísica e Engenharia Biomédica, Faculdade de Ciências, Universidade de Lisboa, Portugal); Ricardo Eleutério (Instituto Biofisica e Engenharia Biomedica Fac Ciencias Univ Lisboa, Portugal)
Breast cancer staging largely depends on the evaluation of whether there are cancer cells in the axillary lymph nodes. This work proposes a non-invasive method of detecting metastases in the lymph nodes using an Ultra-Wideband Microwave Imaging radar system. Energy profiles of the axilla are created with this system in which high energy regions may indicate the presence of cancer cells in the nodes.
10:20 Microwave Breast Imaging Based on an Optimized Two-step Iterative Shrinkage/Thresholding Method
Zhenzhuang Miao (KING'S COLLEGE LONDON, United Kingdom (Great Britain)); Panagiotis Kosmas (King's College London, United Kingdom (Great Britain))
We propose the application of a two-step iterative shrinkage/thresholding method (TwIST) to improve the resolution in microwave imaging applications. The TwIST algorithm is combined with the distorted born iterative method (DBIM) to reconstruct the complex permittivity of two-dimensional (2-D) anatomically realistic numerical breast phantoms. The paper discusses how to optimize the algorithm parameters in order to improve the quality of reconstructions and the robustness of the algorithm. Our results demonstrate the ability of this method to produce images with enhanced resolution in two-dimensional (2-D) microwave breast imaging.
10:40 Coffee Break
11:10 Design and Modeling of a Microwave Imaging System for Breast Cancer Detection
Jorge A. Tobon Vasquez (Politecnico di Torino, Italy); Elia Attardo (Altair Engineering GmbH, Germany); Gianluca Dassano, Francesca Vipiana, Mario Roberto Casu, Marco Vacca, Azzurra Pulimeno and Giuseppe Vecchi (Politecnico di Torino, Italy)
We report on the design and modeling of a microwave-imaging system prototype to be used in research towards early breast cancer detection. A finite element method (FEM) approach is used to model the wideband antenna that acts as transmitter/receiver, and then for modeling and optimizing the geometry of the system. For signals generation and acquisition, low-cost yet high-precision off-the-shelf components replace a costly and bulky vector network analyzer. Comparison between simulations and data measured on the prototype will be presented at the conference. Finally, further validation with a commercial solver (FEKO) is accomplished.
11:30 A Comparative Study of Coherent Time Reversal Minimum Variance Beamformers for Breast Cancer Detection
Md Delwar Hossain (Faculty of Engineering and IT, University of Technology Sydney (UTS), Australia); Ananda Sanagavarapu Mohan (University of Technology Sydney (UTS), Australia)
In this study we consider coherent processing for time reversal microwave imaging for breast cancer detection. We derive coherent time reversal standard Capon beamformer (C-TR-SCB) and coherent time reversal robust Capon beamformer (C-TR-RCB) and compare their imaging performances for breast cancer detection in anatomically realistic heterogeneous 3-D breast phantoms.
11:50 Super-resolution Microwave Imaging: Time-domain Tomography Using Highly Accurate Evolutionary Optimization Method
Fan Yang (Shenzhen ET Medical Technology Co., Ltd., China); Yifan Chen (University of Waikato & University of Electronic Science and Technology of China, New Zealand); Rui Wang and Qingfeng Zhang (Southern University of Science and Technology, China)
This paper presents a novel inverse scattering method for imaging human tissues. The method is established based on an evolutionary algorithm-particle swarm optimization method which can achieve accurate results for high dimensional problems. The use of time domain data allows multiple frequency selectivity. 2D FDTD simulations have shown that the method attains super-resolution that offers 0.1 wavelength with dielectric contrast as low as about 1:1.1. Thus, this method is promising for imaging early stage breast cancer where only small dielectric contrast of 10% could exist between breast tumor and glandular tissues.
12:10 Numerical Heterogeneous Breast Phantoms with Different Resolutions
Nemanja Milosevic (University of Belgrade, France); Marija Nikolic and Branko Kolundzija (University of Belgrade, Serbia); Jasmin Music (WIPL-D, Serbia)
We compare numerical breast phantoms derived from the magnetic resonance imaging with different resolutions. We investigate how the electromagnetic parameter averaging influences the model accuracy. The heterogeneous breast phantoms are in the form of piece-wise homogeneous domains.
12:30 Criterion for the Optimal Choice of the Treatment Conditions in Magnetic Nanoparticle Hyperthermia: Assesment in 3D Realistic Numerical Head Model
Gennaro Bellizzi (University of Naples Federico II, Italy); Ovidio Mario Bucci (University of Naples, Italy)
The paper deals with Magnetic NanoParticle Hyperthermia and aims at presenting some results of an extensive numerical study assessing the effectiveness of a recently proposed optimization criterion, for the choice of the magnetic field and nanoparticle features, in the case of brain tumors located in 3D realistic models of human head.

C4 SimTools: [C] Advances in Commercial Electromagnetic Simulation Tools

Antennas/Bridging other Areas
Room: Diogo Cão (Aud 8)
Chairs: Marc Rütschlin (Dassault Systèmes, Germany), Winfried Simon (IMST GmbH, Germany)
9:00 Making Better Antenna Design Choices with Antenna Magus
Konrad Brand, Brian K Woods, Thomas Sickel and Daniel Barnard (Magus (Pty) Ltd, South Africa)
Antenna design choices are influenced by many factors, including prior exposure to particular topologies, material and manufacturing limitations and space constraints. During the design process, engineers need to make trade-offs between competing requirements. Being able to process information and use CEM tools efficiently can be critical in making intelligent choices. In order to help identify and navigate design choices, Antenna Magus has introduced a Specification-based design workflow. Design requirements may be used to identify candidate antennas which can be researched and explored efficiently, both inside Antenna Magus and through links to various CEM tools. This paper will step through a practical design and highlight how Antenna Magus, in conjunction with traditional CEM tools, may be used to avoid pitfalls, make better design choices and accelerate the process.
9:20 The XPU Technology for Fast and Efficient FDTD Simulations Using Modern CPUs Cache Memory Bandwidth
Winfried Simon and Andreas Lauer (IMST GmbH, Germany); Andreas Wien (IMST, Germany)
EM Simulations play a key role in the design of antennas and RF components. Due to increasing complexity, higher package density or taking into account environmental aspects the simulation effort is steadily rising so simulation acceleration techniques become more and more important. Solutions based on graphic cards (GPU) are expensive and limited in usable memory. This paper presents the XPU technology which is a smart implementation of the Finite Difference Time Domain (FDTD) algorithm on modern CPU architectures. It can drastically reduce simulation times while maintaining full access to the available RAM.
9:40 The Antenna Toolbox for Matlab (AToM)
Pavel Hazdra, Miloslav Capek and Milos Mazanek (Czech Technical University in Prague, Czech Republic); Zbynek Raida (Brno University of Technology, Czech Republic); Jaroslav Rymus (MECAS ESI, Czech Republic)
This contribution presents recent development of the Antenna Toolbox for Matlab (AToM). The toolbox utilize novel theoretical findings related to characteristic mode decomposition and the so-called source concept, by which all antenna characteristics are represented solely by means of currents.
10:00 Overview of Recent Advances in the Electromagnetic Field Solver FEKO
Andrés G. Aguilar (Altair Engineering GmbH, Germany); Johann van Tonder and Ulrich Jakobus (Altair Development S.A. (Pty) Ltd); Frank Illenseer (Altair Engineering GmbH, Germany)
In this paper, an overview of the most recent advances for two high frequency solvers and their hybrid combinations with full wave solvers in the computational electromagnetics code FEKO is given. These are improvements to the Ray-Launching Geometrical Optics (RL-GO) method, and the hybridisation between the Multilevel Fast Multipole Method (MLFMM) and Physical Optics (PO) and its large element version LE-PO. The ray-tracing has been accelerated for RL-GO by using a kd-tree based ray-intersection algorithm and an adaptive ray-launching scheme, where the latter also reduces the memory consumption. Moreover, it is shown that curvilinear meshing for RL-GO leads to more accurate results when objects with a curved surface are involved. An iterative MLFMM/PO or MLFMM/LE-PO hybrid scheme with bi-directional coupling between the two methods is also introduced for extremely large structures, drastically reducing the memory and run-times used. Both methods are validated and compared with other numerical methods.
10:20 State of the Art Antenna Simulation with CST STUDIO SUITE
Marc Rütschlin (Dassault Systèmes, Germany); Tilmann Wittig (CST AG, Germany)
The System Assembly and Modelling framework in CST STUDIO SUITE allows the construction of an entire system consisting of antenna (or multiple antennas), matching or feed networks, and the environment at a schematic and three-dimensional level. From this system level description studies can be derived which allow the user to focus on individual stages of the design, e.g. the antenna on feed network on its own, but also allows these designs be performed in the context of the system. Antenna array designs can be performed at a unit cell and full 3D model level, and the integrated performance of antennas in electrically large environments can be studied. Using an integrated design environment, which enables simulation of antennas across multiple physical domains in multi-scale environments, allows the engineer to work in a flexible and efficient way, and gives opportunities for antenna design which a multiple-tool solution is not able to provide.
10:40 Coffee Break
11:10 SEMCAD X Matterhorn: A Novel Approach to Achieve Realism in Highly Complex Environments
Nicolas Chavannes (Schmid and Partner Engineering AG)
In the ever expanding field of electromagnetics research, a computational platform which is capable of solving multidisciplinary electromagnetic-related problems is crucial for the success of product development and scientific research. To conduct an in-depth electromagnetic analysis, numerical simulation has proven to greatly enhance R&D processes, allowing to provide insightful information which is not always accessible through current measurement techniques. In particular virtual prototyping and optimization within industrial processes are pushing the limits towards more realism and thus are calling for increasingly enhanced numerical tools. On the basis of a state-of-the-art simulation platform, this paper outlines selected applications of recent numerical techniques in various EM-related fields to reveal the distinct advantages of employing cutting-edge computational approaches.
11:30 Mesh Assembly Framework for Hybrid 3D FEM/FEBI/MoM Electromagnetic Simulations
In this paper we will introduce a powerful 3D electromagnetic simulation framework for meshing and solving multi-scale 3D high frequency systems including rapid parametric studies. The fundamental aspect of this framework is to break up a complex model into 3D components which can be meshed independently and then assembled. This method, called assembly meshing, provides several benefits: more robust meshing, reuse of component meshes, accelerated system meshing by creation of the 3D component meshes in parallel, and accelerated parametric studies. In addition, the most appropriate meshing and solver algorithms can be used for each component. All the aforementioned benefits are essential for a robust and efficient 3D system simulator.
11:50 WIPL-D: Advances in EM Simulation
Branko Kolundzija and Miodrag Tasic (University of Belgrade, Serbia); Milos Pavlovic (WIPL-D DOO, Serbia)
Standard WIPL-D Pro 3D EM solver is based on higher order Method of Moment (MoM) solution of Surface Integral Equations (SIEs). Using patches of maximum size of 2λ the number of unknowns needed per λ2 is reduced down to 25 (50) for metallic (dielectric structures. Owing to parallelization and usage of GPU cards the maximum solvable problem in one day is limited to 20,000 λ2. Using up to 3 symmetry planes and "smart reduction" option for expansion orders, the limit for electrical area can be increased for an order of magnitude. Limits of standard WIPL-D Pro 3D EM solver are extended using 1) advanced matrix equilibration to balance source/field quantities in SIEs and basis/test functions in MoM solution, 2) new generation of integral methods for highly accurate MoM matrix elements, and 3) modified Physical optics driven MoM.
12:10 New Fast and Robust Modelling Algorithms for Electrically Large Antennas and Platforms
This paper presents two new modelling algorithms that was recently added to the commercially available GRASP software package for electrically large antenna and scattering problems. In particular, a new higher-order multilevel fast multipole solver (HO-MLFMM) provides very high simulation accuracy while requiring significantly less memory and CPU time than the commonly available low-order MLFMM. At the same time, the solver incorporates a generalised form of the underlying surface integral equations, which allows the use of non-connected meshes and enhances the robustness in real-life applications. As a further addition to GRASP, we outline a new Fast-PO algorithm which provide accelerated integration of Physical Optics currents as well as surface currents in general. The algorithm eliminates some of the limitations of previously published methods, e.g., by allowing observation points located well within the near-field region of the antenna without resorting to a much slower direct surface integration.
12:30 GPU Advancements Reduce Simulation Times for 25 GHz Automotive Radar Models
Jeff Barney (Remcom, Inc., USA)
The high frequencies utilized by automotive radar sensors, coupled with the electrically large fascia in front of the sensors, have posed a challenge for simulation software in the form of long simulation times. Advances in NVIDIA graphics processing units (GPUs) have alleviated this problem, increasing the productivity of RF engineers who need high fidelity simulations of a sensor behind fascia. Using a 25 GHz short-range radar (SRR) model, this paper compares multiple GPU architectures released in 2007 through 2013 to look at the downward trend in simulation times. A larger than 65% decrease in simulation times is observed, which allows a fully detailed sensor simulation to run in less than 4 hours on modern GPUs.

Tuesday, April 14 9:00 - 10:40 (Europe/Berlin)

CC4 OTA: Over the Air (OTA) Testing in Antennas and Multiple Devices

Measurements/Cellular Communications
Room: Pêro Escobar (Pav 3A)
Chairs: Jan Carlsson (Provinn AB, Sweden), Anton Skårbratt (Bluetest AB, Sweden)
9:00 Measuring User-Induced-Randomness to Evaluate Smart Phone Performance in Real Environments
Per H. Lehne (Telenor Research, Norway); Kashif Mahmood (Telenor, Norway); Andrés Alayón Glazunov (University of Twente, The Netherlands & Chalmers University of Technology, Sweden); Pål R. Grønsund (Telenor & University of Oslo, Norway); Per-Simon Kildal (Chalmers University of Technology, Sweden)
The radiated performance of a wireless device depends on its orientation and position relative to the user. Secondly, antenna performance is different on different devices and it depends on the device model. Hence, to understand the impact of the users' behaviour on the device antenna and the resulting network performance an investigation of the device usage and signal quality is of high importance. This paper presents an analysis based on initial data gathered from smart phones over a period of almost 2 months. The data was obtained from the built-in sensors in the phone, and includes angles of orientation, information about signal quality and the connected network. Some interesting trends regarding typical rotations of the phone are presented. We believe that data of this type has a huge potential for optimizing the device and the network performance, in particular, when the data is correlated with the experienced channel quality.
9:20 802.11p Measurements in Reverberation Chamber
Anton Skårbratt (Bluetest AB, Sweden); Robert Rehammar (Qamcom Research and Technology, Sweden)
This paper presents a reverberation chamber based measurement method for 802.11p devices. Focus lies on analyzing impact of different test scenarios and changes in packet length. A modified version of the vehicle to vehicle channel model UIC is presented, and performance is compared to well-known cellular models.
9:40 Investigation of Mode Stirring with Plates on Platform in a Reverberation Chamber
Madeleine Schilliger Kildal (RanLOS AB & Chalmers University of Technology, Sweden); Xiaoming Chen (Xi'an Jiaotong University, China); Per-Simon Kildal (Chalmers University of Technology, Sweden); Jan Carlsson (Provinn AB, Sweden)
The accuracy of the reverberation chamber has been investigated when mode stirring is performed with plates placed on a rotatable platform, i.e., plate-on-platform stirring. The accuracy and scanning volume of the platform plate are then compared to the regular mode stirring plates that are moving alongside two walls. The results are also compared to physical theoretical models. The mode stirring with plates on platform provides STD of the measurements that are a factor 2 worse than with the original plate and platform stirring of the chamber. Still, this is good enough for accurate measurements above 2 GHz, provided the AUT is also located on the platform, and the STD will be better with larger plates on the platform.
10:00 An Experimental Reconfigurable OTA Chamber
Rashid Mehmood (Wavetronix LLC, USA); Jon Wallace (Lafayette College, USA); Michael Jensen (Brigham Young University, USA)
Over-the-air testing (OTA) testing is a proposed method for characterizing the complete end-to-end performance of wireless devices in a controlled and repeatable propagation environment. While reverberation chambers can be used for OTA testing at relatively low cost, their ability to specify parameters of the propagation environment is limited. We have explored a new type of OTA testing chamber that consists of a dense array of planar antennas placed on the chamber walls. The chamber operates by feeding relatively few of the antennas with the RF test signal while terminating the remaining antennas with reconfigurable impedances. This paper reports on the design of a prototype of this chamber and experimentally confirms that the ROTAC has the potential to provide flexible, low-cost OTA testing.
10:20 Testing of LTE Devices in Transmit Diversity Enabled System Using Reverberation Chamber
There has been a high focus latest years to investigate possible methods for Over-The-Air tests facilitating multi-antenna technologies. This paper presents a method of testing mobile device receive performance when the base station utilise transmit diversity (TM2) in the downlink. The method uses a reverberation chamber combined with a channel emulator, and results for three commercially available LTE devices are shown.

Tuesday, April 14 9:00 - 12:50 (Europe/Berlin)

MA13 Scattering: Scattering and Diffraction

Propagation/Multi Applications
Room: Gil Eanes (Aud 3)
Chairs: Thomas Dallmann (Fraunhofer Institute for High Frequency Physics and Radar Techniques FHR, Germany), Vinh Pham-Xuan (Dublin City University, Ireland)
9:00 Cloaking a Bump Inside a Single Isotropic Lossless Dielectric
Constantinos Valagiannopoulos (Nazarbayev University, Kazakhstan); Nikolaos L. Tsitsas (Aristotle University of Thessaloniki, Greece); Ari Sihvola (Aalto University, Finland)
In this work, we determine the suitable parameters (permittivity and thickness) of a lossless dielectric superstrate slab layer, covering an infinite perfect electric conducting (PEC) plane on which lies a two-dimensional PEC bump, such that, simultaneously: (i) the plane wave reflection by the overall configuration in the absence of the bump resembles closely that by the infinite PEC plane, and (ii) the bump's contribution on the scattered far-field radiated over all directions becomes as small as possible. The scattered field is determined by a semi-analytic integral equation methodology. Optimal superstrate's parameters, achieving both objectives (i) and (ii) within significant numerical accuracy, are computed.
9:20 Thin Diffraction Grating Technology
Andrew Thain (Airbus Defence and Space, France); Anass Jaber (Serma Ingénierie, France); Yannick Platon, Alexandre Hervé and Gilles Peres (Airbus Group Innovations, France); Bruno Pasquier (Airbus Group Innovation, France); Laurent Evain (Airbus SAS, France); Guillaume Cambon (Airbus - SAS, France); François Harly (Airbus, France); Hervé Lenquette and Bertrand Sinigaglia (DGAC, France); Bertrand Spitz (ENAC, France)
Reflective diffraction gratings employ periodic arrays of a given three dimensional structure to produce appropriate constructive and destructive interference to redirect an incident wave. Depending upon the angle of incidence, the thickness required for this structure can range from a fraction of a wavelength to several wavelengths. Whilst such a thickness does not present a problem for optical applications it can make the diffraction grating very bulky for radio applications, notably in the lower frequency bands. This paper presents a new thin diffraction grating employing resonant structures, whose thickness is only 1/34th of a wavelength.
9:40 Influence of the Lightning Protection of Blades on the Field Scattered by a Windturbine
This paper investigates the influence of the lightning protection in windturbine blades for their electromagnetic modelling. Two realistic models of blade with lightning protection are compared with two homogeneous models: metallic and dielectric.
10:00 The Poynting Vector Behavior During the Resonance Scattering of an Obliquely Incident Plane Electromagnetic Wave by a Gyrotropic Cylinder
Vasiliy Es'kin, Alexander Ivoninsky and Alexander Kudrin (University of Nizhny Novgorod, Russia)
The scattering of an H-polarized plane electromagnetic wave by a gyrotropic cylinder in the case of oblique incidence is studied. The emphasis is placed on the behavior of the time-averaged Poynting vector field. The detailed analysis of the spatial structure of the energy flow shows that under certain conditions, a significant increase in the magnitude of the Poynting vector near the cylinder surface takes place compared with that for an isotropic cylinder. The sign reversal of the cylinder-aligned component of the energy flow as a function of the transverse radial coordinate is found to occur when passing from the outer region of the cylinder to its inner region.
10:20 Analysis of Wind Turbines Radar Cross Section for Analyzing the Potential Impact on Weather Radars
Olatz Grande (University of the Basque Country, Spain); Itziar Angulo (University of the Basque Country UPV/EHU & Bilbao School of Engineering, Spain); David Jenn (Naval Postgraduate School, USA); Fernando Aguado (AEMET, Spain); David Guerra (University of the Basque Country, Spain); David de la Vega (University of the Basque Country (UPV/EHU), Spain)
A comprehensive characterization of the radar cross section (RCS) patterns of wind turbines is conducted, by applying Physical Optics approximation and considering specific conditions applicable to the potential impact on weather radars. Results show that monostatic RCS patterns of wind turbines present a significant main lobe generated by the mast of the turbine, perpendicular to the mast surface, extremely directive in the vertical plane, with symmetry with respect to the vertical axis of the mast. Secondary lobes caused by other parts of the turbine are identified, all of them of lower amplitude (at least 10 dB lower). Outcomes of the analysis allow the development of simplified calculation methods of the scattered signals and the potential impact of wind turbines.
10:40 Coffee Break
11:10 Efficient Full-Wave Computation of Radar Cross Section for Multiple Source Locations
Vinh Pham-Xuan, Marissa Condon and Conor Brennan (Dublin City University, Ireland)
A novel technique is presented to solve the problem of computing the radar cross section for multiple source locations. The method uses the interpolative decomposition method to reduce the overall number of linear systems to be solved. In addition, the overlapping domain decomposition method is used to reduce the number of iterations required to solve each individual linear system. A modified MLFMA is applied to reduce the cost of each iteration of the ODDM. Results show very good agreement with measured data and suggest that the error incurred in using interpolative decomposition is negligible. However, a significant computational speed up is achieved with a saving of almost 92%.
11:30 Absorption and Scattering Properties of a Receiving Patch Antenna
Constant M. A. Niamien (Normandie Univ, UNIROUEN, ESIGELEC/IRSEEM, Rouen, France); Sylvain Collardey (University of Rennes 1, France); Kouroch Mahdjoubi (Université de Rennes, France)
This paper deals with the scattering behavior of a resonant 6GHz-square patch antenna printed over lossy FR4 substrate. It is seen that the 50-matched patch only absorbs less than 3% and scatters more than 97% of the total absorbed plus scattered power.
11:50 A Semi-Analytical Expression for the RCS of a Frustum-Shaped Foam Target Support Structure
Thomas Dallmann (Fraunhofer Institute for High Frequency Physics and Radar Techniques FHR, Germany); Dirk Heberling (RWTH Aachen University, Germany)
Within radar cross-section measurement ranges polymeric foam columns are often used for the positioning of radar targets since they have a low radar cross-section. Although the shape of such dielectric structures can be optimized using electromagnetic simulation software, an analytical expression for their radar cross-section is useful for general design rules. Therefore an expression for the monostatic radar cross-section of a dielectric frustum is derived throughout this paper. This expression is discussed in detail and compared to results from an electromagnetic simulation software. The comparison shows that the expression is a useful low-frequency approximation for the estimation of the radar cross-section of dielectric frusta.
12:10 Solution of Volume Integral Equations with Novel Treatment to Strongly Singular Integrals
Gokhun Selcuk (Middle East Technical University & Aselsan Inc, Turkey); Sinan Kurt (TOBB ETU University, Turkey); Seyit Koc (Middle East Technical University, Turkey)
Locally corrected Nyström (LCN) method is applied for the solution of volume integral equations (VIEs). Unlike the conventional method of moments (MoM) procedure, LCN method does not use divergence conforming basis and testing functions to reduce the order of singularity of the integrand. Therefore LCN method needs to handle kernels with higher order singularities. For VIEs, worst singularity is due to the double derivative operator acting on free space Green's function and resulting integrals are referred to strongly singular integrals. Using finite part interpretation we converted strongly singular integrals to regular integrals, for the solution of which conventional numerical methods can be applied. We have solved a three-dimensional scattering problem from a dielectric cube and showed the validity of the method
12:30 Electromagnetic Scattering From a Buried Cylinder Using T-Matrix and Signal-Flow-Graph Approach
Ayman Negm (McMaster University, Canada); Islam Eshrah and Ragia Badr (Cairo University, Egypt)
A fast analytical technique based on T-matrix approach is formulated to solve the problem of direct electromagnetic scattering by an infinite circular cylinder buried in dielectric half-space and illuminated by a normally incident transverse magnetic (TM) plane wave. The technique employs the Signal-Flow-Graph (SFG) model to include all multiple reflections that take place during the scattering process. The selection of the size of the obtained T-matrix is also discussed.

MA15 Multiband: Multiband and wideband antennas

Antennas/Multi Applications
Diogo de Silves (Room 1.08)
Chairs: Giuseppe Di Massa (University of Calabria, Italy), María García-Vigueras (IETR-INSA Rennes, France), Rodolfo Ravanelli (Thales Alenia Space Italy SpA, Italy)
9:00 Wide Band, Low Profile and Circular Polarized K/Ka Band Antenna
Przemyslaw Gorski (Laboratory of Electromagnetics and Acoustics / École Polytechnique Fédérale de Lausanne &amp; LEMA); Joana Silva (Huber+Suhner, Switzerland); Juan R Mosig (Ecole Polytechnique Federale de Lausanne, Switzerland)
This paper presents a wideband circular polarized planar antenna element for both K and Ka band. The proposed solution is composed by several thin layers of dielectric substrate that allocate two circular stacked patches, a crossed-slot and two fork-shaped feedings. This antenna element is a good candidate for developing high-gain antenna array for the next generation of multimedia services in Ka-band.
9:20 A Wideband Strip-Helical Antenna with a Parasitic Patch
Xihui Tang (Shenzhen University, China); Yunliang Long (Sun Yat-Sen University, China)
This paper presents a new wideband and low-profile strip-helical antenna with a parasitic patch for circular polarization (CP). A helix with 2.5-turns and pitch angle of 5 degree, made of wide metallic strip, excites a circularly polarized wave with an axial ratio bandwidth of 17%. With the aim of improving AR bandwidth, a circular patch is capacitive coupled to the open end of the strip-helix. The parasitic patch not only reduces the reflection at the open end of the strip-helix, but also excites another nearby circularly polarized resonance. Simulated results show that the proposed antenna has an impedance bandwidth of 56%, and an AR bandwidth of 41% in its low axial height of 0.25 lamda, where lamda is the wavelength in free space at center operation frequency.
9:40 A K/Ka/EHF Feed Chain for Dual-Use Telecom
Rodolfo Ravanelli (Thales Alenia Space Italy SpA, Italy); Pierluigi Cecchini (Thales Alenia Space Italia S.p.A., Italy); Roberto Mizzoni (Thales Alenia Space Italia, Italy); Giuseppe Addamo (Istituto di Elettr. e di Ingegneria dell'Inform. e delle Telecom. (IEIIT-CNR), Italy); Oscar A. Peverini (Istituto di Elettr. e di Ingegneria dell'Inform. e delle Telecom. ( IEIIT- CNR ), Italy); Riccardo Tascone (Istituto di Elettr. e di Ingegneria dell'Inform. e delle Telecom. (IEIIT- CNR), Italy); Giuseppe Virone (Consiglio Nazionale delle Ricerche, Italy)
A novel triple band, self-diplexing feed system operating in K/Ka/EHF bands is presented. The feed system is particularly suitable in space telecom reflector antennas for dual-use applications. Two different RF chain architectures have been traded-off, designed and optimized through full wave modelling, in order to support the optimal choice solution. An EQM of the selected configuration has been realized and subjected to a full qualification test campaign. Very good correlation of the RF performance to the theoretical design has been achieved.
10:00 Dielectric Wedge Antenna for Pavement Void Detection by Scattering
Stephen Pennock and Hugo Jenks (University of Bath, United Kingdom (Great Britain))
The dielectric wedge antenna is studied here as a wideband antenna that is can be sensitive to signals propagating along or just out of a dielectric surface. This is of particular interest in using GPR techniques to identify the condition of a road and may well find broader applications. Measured and theoretical results agree well and show the wideband characteristics that are sought. The feed point appears to be the major factor determining the input match, and work is continuing on better excitation arrangements.
10:20 A Compact Hybrid Dielectric Resonator Antenna with a Meandered Slot Ring and Cavity Backing Offering Wideband Operation
Symon K. Podilchak (Heriot-Watt University, United Kingdom (Great Britain)); Jonathan Jonstone (Queen's University & Royal Military College of Canada, Canada); Michel Clénet (Defence Research and Development Canada, Canada); Yahia Antar (Royal Military College of Canada, Canada)
This summary article proposes a new and compact cavity-backed antenna structure offering circular polarization where a dielectric resonator (DR) element is surrounded by a meandered circular slot ring etched in the antenna ground plane (90mm by 90mm) to improve gain and radiation performance values. In particular, antenna gain values are greater than 3dBic from 1.10GHz to 1.72GHz defining a bandwidth of more than 35%. The DR for the antenna is cylindrical in shape with Er = 30 and excites four radiating HE11d modes which are driven by four, quadrature fed aperture coupled slots. Such a compact implementation hybridizes operation of the DR with its meandered circular slot ring as well as the four aperture coupled slots. Measurements and simulations are in agreement and the proposed design technique to employ such a secondary meandered slot ring may also be useful to improve antenna gain and efficiency for other compact antenna implementations.
10:40 Coffee Break
11:10 A Design Strategy of Active Matched Small-Antennas with Non-Foster Elements
Fernando Albarracín-Vargas (Directed Energy Research Center, TII, United Arab Emirates); Eduardo Ugarte-Muñoz (Universitiy Carlos III in Madrid, Spain); Daniel Segovia-Vargas (Universidad Carlos III de Madrid, Spain); Vicente Gonzalez-Posadas (Universidad Politecnica de Madrid, Spain)
In this paper, a new strategy for the design of active matched antennas with non-Foster elements is presented. The aim of this work is to complement the design process through considerations of sensitivity to circuitry location, Non-Foster elements stability, radiation efficiency and currents distribution in order to enhance the antenna performance. A design example using an electrically small antenna (ESA) and its realization are presented for describing the proposed strategy.
11:30 Wideband Matching of Handset Antenna Ports At Noncontiguous Frequency Bands
Anu Lehtovuori (Aalto University, Finland); Janne Ilvonen (Aalto University School of Electrical Engineering, Finland); Risto Valkonen (Nokia Bell Labs, Finland)
Due to the mutual coupling between the different excited ports, designing multiple wideband matching circuits for handset antennas is not straightforward. This paper presents design principles for wideband matching circuits of two-ports and analyzes their significance in the case of multiple noncontiguous frequency bands. The proposed optimization procedure helps to design matching circuits, which may enlarge passbands, improve isolation between antenna elements, and most important, improve efficiency in the antenna design. General principles have been illustrated with examples, and also measurement results are given.
11:50 Rotational Design Space Reduction for Cost-Efficient Multi-Objective Antenna Optimization
Slawomir Koziel and Adrian Bekasiewicz (Gdansk University of Technology, Poland)
Cost-efficient multi-objective design of antenna structures is presented. Our approach is based on design space reduction algorithm using auxiliary single-objective optimization runs and coordinate system rotation. The initial set of Pareto-optimal solutions is obtained by optimizing a response surface approximation model established in the reduced space using coarse-discretization EM simulation data. The optimization engine is multi-objective evolutionary algorithm (MOEA). The designs obtained by MOEA are subsequently refined by means of response correction techniques. Our approach is demonstrated using a planar UWB dipole antenna.
12:10 Dual-Polarized Patch Antenna for Virtual Antenna Array Based Radio Channel Measurements At 10 GHz
Marko Sonkki, Veikko Hovinen and Nuutti Tervo (University of Oulu, Finland); Cláudio Dias (Universidade Estadual de Campinas, Brazil); Juha Meinilä (Elektrobit Corporation, Finland); Antti Roivainen (Keysight Technologies Finland Oy, Finland)
This paper presents a dual-polarized patch antenna structure operating at 10.10 GHz center frequency. The antenna structure is designed for a virtual antenna array which is part of a vector network analyzer based radio channel measurement system. The antenna shows 700 MHz -10 dB impedance bandwidth. The isolation between the antenna ports is better than 24 dB across the aforementioned bandwidth. The total efficiency is between -0.75 and -0.2 dB, the maximum gain between 3.8 and 4.9 dB, and the XPD approximately 25 dB over the operating bandwidth.
12:30 Wideband and Compact Fabry-Perot Cavity Antenna Using a Dual-Layer Periodic Planar Structure
Antonio Costanzo (Inria Lille - Nord Europe, France); Sandra Costanzo and Giuseppe Di Massa (University of Calabria, Italy)
A wideband Fabry-Perot cavity antenna, powered by a rectangular waveguide and characterized by an extremely compact size (60 mm x 60mm x 20mm), is designed at the central frequency of 14 GHz. Using both parabolic approximation of the wave equation and the infinite array analysis, a secondary cavity composed by two metal-dielectric layers is designed to enlarge the cavity bandwidth, by performing an anomalous phase inversion in a wide range. A simple transition is used to couple a standard WR-75 waveguide to the cavity. A peak gain of about 20 dB and a 13.5% bandwidth (according to a -3dB gain) is numerically demonstrated.

Tuesday, April 14 9:00 - 10:40 (Europe/Berlin)

MA4 EMI/EMC: EMI/EMC/PIM Chamber design, measurement and instrumentation

Measurements/Multi Applications
Room: João G Zarco (Pav 3C)
Chairs: Sébastien Lalléchère (Université Clermont Auvergne, France), Vince Rodriguez (NSI-MI Technologies, LLC. & University of Mississippi, USA)
9:00 An Ultra-thin Dual-Band Polarization-Independent Metamaterial Absorber for EMI/EMC Applications
Praneeth Munaga (Indian Institute of Technology Kanpur, India); Saptarshi Ghosh (Indian Institute of Technology Indore, India); Somak Bhattacharyya (Indian Institute of Technology, BHU, India); Devkinandan Chaurasiya (IITK, India); Kumar Vaibhav Srivastava (Indian Institute of Technology Kanpur, India)
In this paper, an ultra-thin polarization- independent dual-band metamaterial absorber has been presented in microwave frequency regime. The unit cell structure is composed of tetra-arrow cave structure in the top layer imprinted on a grounded dielectric substrate. The geometrical parameters have been optimized in such a way that near-unity absorption takes place at two different frequency bands (C and X-band). The proposed structure is polarization-insensitive as well as wide-angle absorptive (upto 60 degree) for both TE and TM polarizations. The designed absorber is ultra-thin, compact and appears to be potentially instructive for various EMI/EMC applications.
9:20 Improvement on Radiation Characteristics of Bow-Tie Antenna for EMI Measurement
Kazuki Kanai, Masaki Nagasawa and Ryosuke Suga (Aoyama Gakuin University, Japan); Takenori Yasuzumi (Toshiba Corporation, Japan); Tomoki Uwano and Osamu Hashimoto (Aoyama Gakuin University, Japan); Yukihisa Hasegawa (Toshiba Corporation, Japan)
In this paper, a directional bow-tie antenna for EMI measurements was proposed. For obtaining the directionality, two backward edges of each half element were directly-aliened, and two slits were placed on the elements to suppress the sidelobe level. The reflection coefficient less than -4 dB between 300 and 870 MHz and front to sidelobe ratio of 8.5 dB were measured at 870 MHz.
9:40 A New Measurement Technique and Experimental Validations in Determination SAR of N-Antenna Transmitters Using Scalar E-Field Probes
Dinh Thanh Le (Toyota Motor Corporation (TMC), Japan); Lira Hamada and Soichi Watanabe (National Institute of Information and Communications Technology, Japan)
This paper presents a measurement technique to evaluate the Specific Absorption Rate (SAR) for multi-antenna transmitters such as a mobile phone or the like. Fundamental analysis of SAR formula for the general case of N antennas and experimental validations for the case of three antennas are presented. The key point of the proposed technique is to measure SAR for some different relative phase combinations of the antennas and estimate SAR for any other relative phase combinations. To determine the maximum SAR value of two-antenna devices, only three measurements are necessary while for three-antenna cases, seven measurements are required. The proposed technique suites well for SAR measurement systems using scalar electric field probes, and experimental validations show that estimated SARs and measured SARs are in very good agreement.
10:00 Experimental S-parameters Statistics Under Uncertain Loads Constraints
Sébastien Lalléchère (Université Clermont Auvergne, France); Sébastien Girard (Blaise Pascal University, France)
This contribution addresses the statistical assessment of cables performance via the precise computation of S-parameters statistics. These data are derived by Lagrange interpolation of a given set of measurements assuming uncertainties around terminal load. The proposed philosophy provides useful information to characterize systems under uncertain constraints.
10:20 Utilizing Gain Interpolation for the Removal of Near-field Coupling Effects During EMC Antenna Calibrations
Dennis Lewis (Boeing, USA); Vince Rodriguez (NSI-MI Technologies, LLC. & University of Mississippi, USA); Sandra Fermiñán Rodríguez (ETS-Lindgren, Germany)
Antenna calibrations for EMC emissions and immunity measurement require gain characterization at reduced distances. The current standards for EMC antenna calibrations do not address the near-field antenna-to–antenna interactions that are present during calibration at these reduced distances. These interactions are not present when using these antennas to measure a device and can result in large measurement errors. Extrapolation measurements have been used for many years to measure the far field gain of antennas at reduced distances. This paper uses both computations and measurements to show how the use of interpolation results in a more accurate assessment of antenna gain at distances required for EMC antenna calibrations.

Tuesday, April 14 9:00 - 12:50 (Europe/Berlin)

S5 ArraySpace: Array Antennas for Space

Room: Tristão V Teixeira (Pav 5A)
Chairs: Cyril Mangenot (Api-Space, France), Robert Shaw (CSIRO, Australia)
9:00 Design of Wideband, Wide-Scan Planar Arrays by Combining Connected Arrays and Artificial Dielectrics
Waqas Hassan Syed, Daniele Cavallo, Harshitha Thippur Shivamurthy and Andrea Neto (Delft University of Technology, The Netherlands)
Wideband, wide-scan connected arrays are typically implemented resorting to vertical arrangements of printed circuit boards (PCBs). Here we propose a planar solution realized with a single multi-layer PCB, with consequent reduction of cost and complexity. Artificial dielectric layers (ADLs) are used in place of real dielectric superstrates, as they are characterized by much higher surface-wave efficiency. For the design of the total structure (array loaded with ADL) we used an in-house developed analysis tool, which requires very small computational resources. Both single- and dual-polarized designs are presented, achieving about an octave bandwidth, within a scanning volume of 50 degrees in all azimuthal planes. The total efficiency is higher than 85% and the cross-polarization level lower than -10 dB, within the entire scanning volume.
9:20 Compact Dual-Band Dual-Polarized Antenna Array for Robust Satellite Navigation Receivers
Maysam Ibraheam and Safwat Irteza Butt (Ilmenau University of Technology, Germany); Stefano Caizzone and Achim Dreher (German Aerospace Center (DLR), Germany); Ralf Stephan (Technische Universität Ilmenau, Germany); Matthias Hein (Ilmenau University of Technology, Germany)
Multi-antenna satellite navigation receivers provide precision and robustness against multipath propagation and in-band interferers. However, with the prerequisite of compactness, the radiation efficiency of the array is limited by the strong mutual coupling between its elements. Decoupling and matching networks (DMN) are used to mitigate the coupling and thus enhance the high-order eigenmode radiation efficiencies of the array. Nevertheless, this limitation of efficiency motivates to exploit further sources of diversity and therefore a dual-band dual-polarized compact antenna array with a decoupling and matching network is proposed. The compactness and integration of the receiver are improved by designing the network on a multilayer printed circuit board attached directly to the antenna. The decoupling elements are designed in stripline technology and the matching circuits are designed using lumped elements.
9:40 Prototype 32 Elements Beam Forming Network for 21-GHz Band Broadcasting Satellite
Susumu Nakazawa, Masafumi Nagasaka and Masashi Kamei (NHK, Japan); Shoji Tanaka (NHK Science and Technical Research Laboratories, Japan); Tomohiro Saito (NHK, Japan)
The satellite broadcasting in the 21-GHz band is expected to transmit multi-program services of Super Hi-vision (SHV) and other advanced services. For the implementation of SHV, we assume to allocate two 300-MHz class wideband channels in the band 21.4 - 22.0 GHz. To supply enough power for such a wide band transponder, we proposed array-fed Imaging Reflector Antenna (array-fed IRA). It enables to combine enough power for large capacity signal transmission while the power from each feed horn is keeping small to avoid electrical discharges. We are on a process to fabricate a prototype of 32 elements beam forming network (BFN) for engineering test. Assuming the fabricating BFN, we evaluate the radiation pattern affected by the control error in the BFN for the 21-GHz band broadcasting satellite.
10:00 2 x 2 Stacked Patch Array with Corporate SIW Feeding Network
Eduardo Garcia-Marin and Jose Luis Masa-Campos (Universidad Autonoma de Madrid, Spain); Pablo Sanchez-Olivares (Universidad Politecnica de Madrid, Spain)
A linearly polarized 2x2 patch array uniformly fed by a corporate Substrate Integrated Waveguide (SIW) network for Ku band is presented. The utilization of a SIW corporate topology in the feeding network prevents the antenna from suffering unintended main lobe tilt dispersion. Nevertheless, the inter-element spacing increase, as well as the SLL. Reducing this spacing implies closer discontinuities, such as bends and T-junctions. This degrades the reflection coefficient. Hence, a tradeoff solution has been designed and manufactured, achieving a SLL better than -11 dB and a measured bandwidth similar to the expected in the simulation stage, being 4.4 % at -10 dB. The measured gain reaches 13.1 dB, which corresponds to a 84% radiation efficiency
10:20 Irregular Quad-Mode Antenna Array: Field-of-View Comparison with the Swedish LOFAR Station
David S Prinsloo (ASTRON & Netherlands Institute for Radio Astronomy, The Netherlands); Petrie Meyer (Stellenbosch University, South Africa); Rob Maaskant (CHALMERS, Sweden); Marianna Ivashina (Chalmers University of Technology, Sweden)
The response of a 96 element quad-mode antenna (QMA) array, configured in the layout of a Low Frequency Array (LOFAR) Low Band Antenna (LBA) station, is assessed. Mutual coupling between the four fundamental excitation modes of each QMA is investigated and the maximum gain achieved by the QMA array is compared with the maximum gain of the LBA array. It is shown that the QMA array results in a 5 dB increase in gain toward the horizon with a variation in gain less than 5 dB over a hemispherical Field-of-View (FoV) coverage.
10:40 Coffee Break
11:10 Compact Satellite Navigation Antenna Array Using Off-the-Shelf Ceramic Patch Antennas
Safwat Irteza Butt, Matthias Hein and Maysam Ibraheam (Ilmenau University of Technology, Germany); Ralf Stephan (Technische Universität Ilmenau, Germany); Thomas Harz (PTB Braunschweig, Germany); Yury Bulbin (AntennenTechnnik Badblankenburg, Germany)
We aim at developing a miniaturized four-element satellite navigation receiver to achieve robustness, precision and accuracy in the challenging environments, suitable for economical industry-scale fabrication and assembly. In this paper, we present a four-element compact antenna array for public L1/E1-bands, i.e., 1575.42±2 MHz, based on commercially available ceramic antenna elements. It is observed that due to the compactness of the antenna array the mutual coupling degrades the radiation properties particularly the axial-ratio. We propose a modification in the ground-plane to reduce the axial-ratio below 3 dB in the main-lobe directions necessary for the navigation receivers. Moreover, to mitigate mutual coupling a decoupling and matching network using off-the-shelf directional couplers is presented.
11:30 Transistor Noise Characterization for an SKA Low- Noise Amplifier
Stuart G Hay (CSIRO ICT Centre, Australia); Robert Shaw (CSIRO, Australia)
Noise parameter measurements of six candidate transistors for a Square Kilometer Array (SKA) low-noise amplifier (LNA) are presented. They provide reliable data in the frequency range where some low-noise transistors are inadequately characterized. The results of these measurements inform the design of a prototype SKA LNA with measured minimum noise temperature of 21 K.
11:50 Simultaneous Radiation of Narrow and Wide Beams Exploiting Two Concentric Isophoric Sparse Arrays
Ovidio Mario Bucci (University of Naples, Italy); Stefano Perna (Università degi Studi di Napoli Parthenope, Italy); Daniele Pinchera (University of Cassino, Italy)
In this contribution we investigate the possibility to synthesize two concentric circular sparse array layouts, capable of radiating two different patterns characterized by different beamwidths.
12:10 Shaped Beam Synthesis of Arrays of Real Antennas Via Phase Retrieval and Convex Programming
Jose Ignacio Echeveste (Airbus Defence and Space, Spain); Miguel A. González de Aza (Universidad Politecnica de Madrid, Spain); Jesús Rubio and Rafael Gómez Alcalá (University of Extremadura, Spain)
This work proposes the application of the phase retrieval algorithm to antenna array pattern synthesis problems through convex optimization. Near optimal solutions are obtained that do not yield in local minimums and do not need initial points to converge. The optimization method takes into account the real radiation patterns of the array elements that compose the array and the mutual coupling betweem them with a matrix formulation based on the spherical wave expansion and a finite element analysis of the radiating elements.
12:30 Density-Tapered Planar Arrays for Multibeam and Shaped Beam Coverage in Satellite Communications
Javier Fondevila-Gómez (University of Santiago de Compostela, Spain); Aaron A Salas-Sanchez (University of Trento, Italy & University of Santiago de Compostela, Spain); Juan Rodríguez-González and Francisco Ares-Pena (University of Santiago de Compostela, Spain)
Interest in uniformly illuminated density-tapered planar antenna arrays has recently revived. For arrays consisting of concentric rings of elements, we present a non-stochastic algorithm that calculates ring radii for generation of pencil beams without the need for prior specification of the number of rings. If element phases are allowed to differ, the algorithm also synthesizes density-tapered arrays generating axially symmetric shaped footprint beams (to which the usual distortion methods can be applied to obtain beams with other contour shapes.

W3 ReconfAnt: Adaptive and reconfigurable antennas

Antennas/Wireless Networks
Room: Afonso de Albuquerque (Pav 3B)
Chairs: Adam Narbudowicz (Trinity College Dublin, Ireland & Wroclaw University of Science and Technology, Poland), Alexandru Tatomirescu (Polytechnic University of Bucharest, Romania)
9:00 On Pattern Reconfigurable Antennas Steered by Modulation Scheme
Adam Narbudowicz (Trinity College Dublin, Ireland & Wroclaw University of Science and Technology, Poland); Max James Ammann (Dublin Institute of Technology, Ireland); Dirk Heberling (RWTH Aachen University, Germany)
The paper demonstrates how a modulation constellation can be used to steer the radiation pattern of a reconfigurable omnidirectional circularly polarized antenna. The proposed approach offers the benefit of digital beamforming while using a single antenna: the steering can be executed by low frequency electronics and independently for each frequency channel. In the proposed study, the antenna is excited by a signal generated by two I/Q modulators. By appropriately changing the I and Q components, a phase shift is generated which effectively steers the radiation pattern. The results were achieved using co-simulation between CST Microwave Studio and CST Design Studio.
9:20 A Mono, Dual and Triple Band Switchable Metamaterial-based Antenna
Ali Mansoul and Farid Ghanem (Centre de Developpement des Technologies Avancees, Algeria); Mohamed Trabelsi (Ecole Nationale Polytechnique d'Alger, Algeria)
This paper presents a multiband frequency reconfigurable antenna based on metamaterials. It is composed of a CPW fed straight-line monopole with three Double Split-Ring Resonators (DSRRs) of different size, disposed at its proximity in the upper and bottom sides. Each cell exhibits a negative permeability over a narrow frequency band over which a magnetic coupling with the monopole is produced. Consequently, three new frequency bands proportional to the electrical length of the three DSRR's are created. By inserting a single switch at each metamaterial cell, it is possible to activate/deactivate them. The activation/deactivation of the different DSSR's can then be used not only to enable/disable the new bands, but also to control the operating band of the monopole. In total, the proposed antenna can be operated in eight (8) different modes corresponding to mono, dual and triple band operations.
9:40 Reconfigurable Patch Antenna for Wireless Applications
Noman Aftab (UET Lahore, Pakistan); Hassan Tariq Tariq Chattha (Islamic University of Madinah, Madinah, Saudi Arab, Saudi Arabia & Islamic University in Madinah, Pakistan); Yasir Jamal (University of Engineering & Technology Lahore Faisalabad Campus, Pakistan); Abubakar Sharif (GC University Faisalabad, Pakistan); Yi Huang (University of Liverpool, United Kingdom (Great Britain))
This paper presents a new reconfigurable microstrip patch antenna. The reconfigurability allows the antenna to carry communications over different WLAN band frequencies (2.4 GHz, 3.6 GHz, 4.9 GHz, 5 GHz, and 5.9 GHz). It mainly consists of microstrip and a circular radiating element that is divided into three patches, which are being reconfigured/switched, by the use of silicon PIN diodes. PIN diodes are chosen for achieving reconfigurability as being more practical due to their high switching capabilities. A dc bias tee is used to apply dc biasing to the PIN diodes. A prototype of the antenna was manufactured and tested to verify the results.
10:00 Additively Manufactured Shape Reconfigurable Loop Antennas
Daniel L Revier (Texas Instruments, USA); Christy Saintsing, Manos M. Tentzeris, Kai Yu and H. Jerry Qi (Georgia Institute of Technology, USA)
Additive Manufacturing (AM) is an exciting new technology that has vastly altered both the industrial and consumer technological landscape. The unique capabilities offered by AM enable designers of all sorts to realize previously unmanufacturable shapes and material combinations in order to enhance current applications. While these advancements offered by AM have been studied and utilized extensively in a more mechanically inclined environment, they are just now being envisioned for use with antennas and other radio frequency devices. This paper investigates the use of shape memory polymer geometries that can be easily manufactured in an Objet material jetting printer for use as a "backbone" for wire antennas.
10:20 Optically Controlled Reconfigurable Antenna Array Based on a Slotted Circular Waveguide
Igor da Costa and Arismar Cerqueira S. Jr. (INATEL, Brazil); Edson Reis (BRADAR, Brazil); Danilo Spadoti (Universidade Federal de Itajubá - UNIFEI, Brazil); João Moreira (BRADAR, Brazil)
This paper describes the development of an optically controlled reconfigurable antenna array based on a slotted circular waveguide for distributed antenna system applications. Four slots, each one optically controlled by a photoconductive switch, composes this novel antenna for enabling radiation pattern reconfiguration. Experimental results have been shown in excellent agreement with numerical simulations carried out using ANSYS HFSS. The proposed antenna provides a bandwidth of approximately 10% from 5.8 to 6.4GHz and a reconfigurable radiation pattern with five different configurations depending on photoconductive switches' states. The antenna gain at 5.8 GHz varies from 4.91 to 7.97dBi.
10:40 Coffee Break
11:10 Alternative Duplexing for LTE FDD Using the Theory of Characteristic Modes
Alexandru Tatomirescu (Polytechnic University of Bucharest, Romania); Gert Pedersen (Aalborg University, Denmark)
In this work, the duplex filter is replaced by equipping the Rx and Tx branch of the front-end with dedicated antennas. Duplexing is achieved by less demanding tunable filters and electromagnetic isolation between the two antennas. In order to satisfy the requirements for antenna isolation, the theory of characteristic modes has been used to obtain wideband antenna isolation. In order to excite different characteristic modes tunable antenna elements are used. Tunability is introduced to compensate for the narrow band Tx antenna. Both antennas are extremely compact in order to keep the overall antenna volume small. The proposed antenna system has been evaluated through simulations and measurements and it was confirmed that the required isolation can be achieved even when the two antennas are matched at the same frequency.
11:30 Reactively Matched Long Slot Linear Connected Array Antenna
Hernán V. Barba Molina (Escuela Politécnica Nacional & IEEE, Ecuador); Jan Hesselbarth (University of Stuttgart & IHF -- Institute of Radio Frequency Technology, Germany)
A linear three-element slot antenna array with intentionally strong mutual coupling between the elements, a so-called connected array, is presented. By simultaneously feeding all three ports of the array, at different frequencies over an octave bandwidth and with different phases, feed-port reflection coefficients with magnitude larger than one, or negative active feed impedances, can occur. A reactive pre-match is proposed to avoid these particular cases and entirely passive impedance transformation to 50 Ohm feed impedance becomes possible. This concept is illustrated by experiments with a radiating slot of a length of 40% of a wavelength at 1.7 GHz, with three equidistant feeds, operating with in-phase feed signals at 1.7 GHz, 2.55 GHz and 3.4 GHz, respectively, as well as with phase-increment feed for beam steering at 1.7 GHz. Beam steering towards 30 degrees off broadside at 1.7 GHz is demonstrated from this slot.
11:50 Design and Performance Evaluation of a Switched-Beam Antenna Array for 60 GHz WPAN Applications
Marc Imbert (Universitat Politècnica de Catalunya, Spain); Anna Papio Toda (Energous Corporation, USA); Franco De Flaviis (University of California, Irvine, USA); Luis Jofre (Universitat Politecnica de Catalunya, Spain); Jordi Romeu (Universitat Politècnica de Catalunya, Spain)
In this paper, the design and performance evaluation of a switched-beam antenna array to operate in the 60 GHz band for short-range WPAN applications is presented. In order to achieve high throughput wireless communications, highly directive antennas are required. In addition, beam-steering capabilities are also needed to deal with the high user random mobility of indoor environments. For these reasons, we propose a design based on a 5x5 slot antenna array and a dielectric inhomogeneous gradient-index flat lens to steer and enhance the radiation in a particular direction. A total of 25 high-gain beams can be selected individually to scan in both theta and phi directions. Our measurement results show that we can achieve 17.25dB of broadside gain, beam-steering capabilities from +20º to -20º with more than 15dB of gain, and up to ±52º with around 12.8dB, with low side-lobe levels, in the entire frequency band from 57 to 64GHz.
12:10 Three Dimensional Microfabricated Broadband Patch and Multifunction Reconfigurable Antennae for 60 GHz Applications
Volkan Hunerli (Middle East Technical University, Turkey); Hema Mopidevi (Utah State University, USA); Engin Cagatay (Institute for Nanoelectronics, Technische Universität München, Germany); Marc Imbert and Jordi Romeu (Universitat Politècnica de Catalunya, Spain); Luis Jofre (Universitat Politecnica de Catalunya, Spain); Bedri Cetiner (Utah State University, USA); Necmi Biyikli (Bilkent University & UNAM, National Nanotechnology Research Center, Turkey)
In this paper we present two antenna designs capable of covering the IEEE 802.11ad frequency band. We report the design, microfabrication and characterization of a broadband patch and multifunction reconfigurable antennae. For the patch antenna, the energy is coupled with a CB CPW-fed loop slot, resulting in a broad bandwidth. The feed circuitry along with the loop is formed on a quartz substrate, on top of which an SU-8-based 3D structure with air cavities is microfabricated. The patch metallization is deposited on top of this structure. The second design is a CB CPW-fed loop slot coupled patch antenna with a parasitic layer on top. The feed circuitry and the loop is formed on a quartz substrate. On top, the patch metallization is patterned on another quartz substrate. The parasitic pixels are deposited on top of these two quartz layers on top of an SU-8 based 3D structure with air cavities.
12:30 Numerical Analysis of Reconfigurable Plasma Antenna Arrays
Anuar Fernandez Olvera (Eindhoven University of Technology, The Netherlands); Davide Melazzi (University of Padova, Italy); Vito Lancellotti (Eindhoven University of Technology, The Netherlands)
We report on the numerical analysis of a reconfigurable plasma antenna array (PAA) comprised of a metallic half-wavelength dipole and plasma tubes. Our simulations indicate that beam-forming and beam-steering can be realized and controlled by selectively switching the plasma tubes on and off.

WS4 Julien: In Memoriam of Julien Perruisseau-Carrier

Scientific Workshop
Room: Paulo da Gama (Pav 5B)
Chairs: Sean V Hum (University of Toronto, Canada), Juan R Mosig (Ecole Polytechnique Federale de Lausanne, Switzerland)
9:00 Advances in reconfigurable antennas and space-fed arrays: Contributions by Julien Perruisseau-Carrier
Sean V Hum (University of Toronto, Canada)
Advances in reconfigurable antennas and space-fed arrays: Contributions by Julien Perruisseau-Carrier
9:20 In the memory of Julien Perruisseau-Carrier: His contributions to reconfigurable reflectarrays and COST Actions on Antennas
Ozlem Aydin Civi (Middle East Technical University, Turkey)
In the memory of Julien Perruisseau-Carrier: His contributions to reconfigurable reflectarrays and COST Actions on Antennas
9:40 Reconfigurable antennas and arrays for cognitive radio: polarization and frequency agility and beamforming
Apostolos Georgiadis (Heriot-Watt University, United Kingdom (Great Britain))
Reconfigurable antennas and arrays for cognitive radio: polarization and frequency agility and beamforming
10:00 The contribution of Julien Perruisseau-Carrier to reconfigurable reflectarray antennas
Jose A. Encinar, Eduardo Carrasco and Mariano Barba (Universidad Politecnica de Madrid, Spain)
The contribution of Julien Perruisseau-Carrier to reconfigurable reflectarray antennas
10:20 Dynamic reconfiguration of plasmonic reflectarrays using graphene: a review of the research led by Prof. Perruisseau-Carrier
Eduardo Carrasco (Universidad Politecnica de Madrid, Spain); Michele Tamagnone (Ecole Polytechnique Fédérale de Lausanne, Switzerland); Juan R Mosig (Ecole Polytechnique Federale de Lausanne, Switzerland)
Dynamic reconfiguration of plasmonic reflectarrays using graphene: a review of the research led by Prof. Perruisseau-Carrier
10:40 The Orbital Angular Momentum (OAM) Multiplexing Controversy: OAM as a Subset of MIMO
Michele Tamagnone (Ecole Polytechnique Fédérale de Lausanne, Switzerland); Joana Silva (Huber+Suhner, Switzerland); Santiago Capdevila (SWISSto12, Switzerland); Juan R Mosig (Ecole Polytechnique Federale de Lausanne, Switzerland); Julien Perruisseau-Carrier (Ecole Polytechnique Fédérale de Lausanne & EPFL, Switzerland)
Recently the orbital angular momentum (OAM) multiplexing scheme has been proposed to increase supposedly without limit the channel capacity between a transmitter and a receiver nodes communicating in line of sight. A controversy arose about the far-field effectiveness of this method and about it being or not a subset of MIMO communication schemes. In this contribution we first illustrate that OAM multiplexing can be completely understood as line of sight MIMO, and hence that the technique cannot bring additional advantages in far field communications. Secondly, we show that it is possible to build similar line of sight near field MIMO systems based on lenses which perform better than their OAM counterparts.
11:00 MEMS-based tunable true-time delay and composite right/left handed transmission lines
Kagan Topalli (TUBITAK Space Technologies Research Institute, Turkey)
MEMS-based tunable true-time delay and composite right/left handed transmission lines
11:20 Pros and cons of patterning graphene layers
Arya Fallahi (IT'IS Foundation, Switzerland)
Pros and cons of patterning graphene layers
11:40 Closing remarks
Juan R Mosig (Ecole Polytechnique Federale de Lausanne, Switzerland); Sean V Hum (University of Toronto, Canada)
Closing remarks

Tuesday, April 14 11:10 - 12:50 (Europe/Berlin)

CC5 UrbanProp: Urban Propagation

Propagation/Cellular Communications
Room: Pêro Escobar (Pav 3A)
Chairs: Lúcio Studer Ferreira (ISTEC / ULHT COPELABS / INESC-ID, Portugal), Claude Oestges (Université Catholique de Louvain, Belgium)
11:10 Investigation of Ray-Tracing Accuracy in Street Cell Environment for High-SHF and EHF Bands
Nobutaka Omaki (NTT DOCOMO INC., Japan); Ngochao Tran, Koshiro Kitao, Tetsuro Imai and Yukihiko Okumura (NTT DOCOMO, INC., Japan); Motoharu Sasaki and Wataru Yamada (NTT, Japan)
Recently, mobile networks employing high-speed high-capacity communications have been investigated extensively to satisfy the strong demand for the faster and larger data communication beyond 2020 as the 5th generation (5G) mobile communication system. As one of the approaches, High-SHF (6  30 GHz) and EHF (mainly 30 - 60 GHz) bands are the candidates to utilize the relatively wide frequency band widths. Accordingly, the characteristics of radio propagation loss in the frequency bands must be characterized. We investigate the characteristics of radio propagation loss in a street cell environment for High-SHF and EHF bands using Ray-Tracing (RT) based on measurement results. We evaluate the accuracy of RT calculation by comparing with measurement result. The trends of the accuracy are different between Line-of-Site (LOS) and Non Line-of-Site (NLOS) situations and between different routes. For further investigation, the number of rays in RT simulation is studied to improve the accuracy.
11:30 Path Loss Characteristics At 800 MHz to 37 GHz in Urban Street Microcell Environment
Motoharu Sasaki and Wataru Yamada (NTT, Japan); Takatoshi Sugiyama (Kogakuin University, Japan); Masato Mizoguchi (NTT, Japan); Tetsuro Imai (NTT DOCOMO, INC., Japan)
A model for predicting path loss from the microwave band to the millimeter wave band for street microcell environments is presented. Developed on the basis of measurement results, the model uses visibility to predict path loss characteristics. It reduces the root mean square errors of prediction results by more than 2.5 dB at bands above 26 GHz, demonstrating its ability to predict measurement results accurately.
11:50 Mixed Path Loss Model for Urban Environments
Sajjad Hussain (National University of Sciences and Technology, Pakistan); Dung Trinh and Conor Brennan (Dublin City University, Ireland)
In this paper a hybrid method is proposed for computing electromagnetic wave propagation in urban areas. The Block Forward Backward Method (BFBM) is with the Fast Fourier Transform to predict fields far away from the transmitting antenna where 2D propagation in the vertical plane dominates. Nearer the transmitter where lateral propagation effects are more important a 3D ray tracing tool is used. Good agreement is achieved when compared to measured data in both regions.
12:10 Joint Ray Launching Method for Indoor to Outdoor Propagation Prediction Based on Ray Aggregation
Bing Xia (University of Sheffield, United Kingdom (Great Britain)); Zhihua Lai (Ranplan Wireless Network Design Ltd, University of Sheffield, United Kingdom (Great Britain)); Jie Zhang (University of Sheffield, Dept. of Electronic and Electrical Engineering, United Kingdom (Great Britain))
A joint indoor to outdoor ray launching algorithm is proposed in this paper. Different resolutions are consider for indoor and outdoor simulations. Instead of using conventional sampling technique to extract rays from a finer resolution, a novel method, named Ray Aggregation, is applied to minimise the loss of accuracy while benefiting from the computational cost of a coarse resolution. Moreover, this model will be presented with two simulations based on the general 2.4 GHz 802.11n wireless local area network.
12:30 Path Loss Model and Root Mean Square Delay Spread Characterization of Near-Ground Outdoor UWB Channel
Ahmed M. Al-Samman (Universiti Teknologi Malaysia, Malaysia); Tharek Abdul Rahman (Wireless Communication Centre, Malaysia); Jamal Nasir (Wireless CommunicationCentre, Universiti tTechnologi Malaysia, Malaysia); Mohd Haizal Jamaluddin (Universiti Teknologi Malaysia, Malaysia); Mohsen Khalily (University of Surrey & 5G Innovation Centre, Institute for Communication Systems (ICS), United Kingdom (Great Britain)); Muhammad Ramlee Kamarudin (Cranfield University, United Kingdom (Great Britain))
The large bandwidth of ultra wideband (UWB) makes it attractive in high speed transmission applications. However, the possibility of frequency selectivity of the channel is high due to this bandwidth. Channel characterization is important to study the behavior of the channel. The ground reflection effects are important parameters affecting the ultra wideband channel. In this paper, based on outdoor time domain measurements, path loss model and root mean square (RMS) delay spread characteristics for near-ground (NG) UWB channel have been presented. Moreover, the interdependencies of these characteristics of the multipath channel are also investigated. The NG UWB channel characteristics are compared to the UWB channel above the ground. From the results it has been found that the path loss in NG UWB channel is less as compared to the above ground case. Also, the values of RMS delay spread are low.

DS2 PropAeron: Propagation in Aeronautics and Navigation

Propagation/Defense and Secutity
Room: João G Zarco (Pav 3C)
Chairs: Uwe-Carsten G. Fiebig (German Aerospace Center (DLR), Germany), Andrew Thain (Airbus Defence and Space, France)
11:10 Radio-Channel Characterization of an Over-Sea Communication
Ismail Ben Mabrouk (Loughborough University, United Kingdom (Great Britain)); José Carlos Reyes (University of Bergen, Bergen, Norway)
This paper presents comprehensive experimental results obtained from narrowband and wideband radio-channel measurements in a maritime environment at 5.8 GHz. From continuous-wave (CW) measurement data, large scale distance-power curves and path-loss exponents of a practical scenario are determined. Other relevant parameters, such as the mean excess delay, and the coherence bandwidth are extracted from the wideband-measurement data. Results show a propagation behavior that is specific for these environments.
11:30 Prediction by Simulation of Performances of RFID Systems in Aeronautic Environments
Alexandre Piche and Richard Perraud (Airbus Group Innovations); Gilles Peres (Airbus Group Innovations, France)
Wireless networks are widely used in urban or office environments and are increasingly considered as an attractive solution for various aeronautic applications. Current investigations focus in particular on RFID technologies because of their low cost, ease of installation and technical background. The question of the optimal positioning of transmitters and receivers checking all industrial constraints arises during the design phase. Numerical modelling appears as a powerful way to assess this optimization step. The objective of this paper is thus to present a methodology to predict performances of RFID systems in complex aeronautic environments.
11:50 Measured Doppler Power Profiles for Air to Ground Radio Links
Nicolas Schneckenburger, Dmitriy Shutin, Thomas Jost and Uwe-Carsten G. Fiebig (German Aerospace Center (DLR), Germany)
The paper presents results from flight trials conducted to investigate the characteristics of the L-band air to ground radio channel. Hereby, the transmitter is located on ground and the receiver in a flying aircraft. Within the paper the setup of the measurements is described. As results, we present Doppler power profiles. The results indicate that strong multipaths are present in the air to ground radio channel. It is shown, that the characteristics of the multipaths strongly depend on the distance between the receiver and transmitter.
12:10 Comparison of Metrics for Clutter Data Comparison
Rémi Douvenot (ENAC, France); Vincent Fabbro (ONERA, France); Kevin Elis (CNES, France); Yvonick Hurtaud (DGA/MI, France)
Some radar applications require to measure a distance between different sets of clutter data. For instance, refractivity from clutter (RFC) is a technique to retrieve the atmospheric conditions from the measured clutter in the absence of target. The clutter measurements are compared to simulations to infer the refractive index along the pathway. When a distance between two clutter data is required, the L2 norm between data in dB is usually chosen. This paper investigates other metrics and claims that the L2 norm is not the most appropriate.
12:30 Stealthy Buildings for Radio Navigation Applications
Andrew Thain (Airbus Defence and Space, France); Anass Jaber (Serma Ingénierie, France); Jerome Robert, Yannick Platon, Alexandre Hervé and Gilles Peres (Airbus Group Innovations, France); Bruno Pasquier (Airbus Group Innovation, France); Laurent Evain (Airbus SAS, France); Guillaume Cambon (Airbus - SAS, France); François Harly (Airbus, France); Hervé Lenquette and Bertrand Sinigaglia (DGAC, France); Bertrand Spitz (ENAC, France)
It is sometimes necessary to reduce the electromagnetic signature of buildings because of their undesirable effect on aircraft navigation systems. Indeed, planning permission is not granted to buildings close to airport runways unless their electromagnetic signature can be reduced to less than specified regulatory thresholds. This paper presents two solutions for doing this: A thick, conventional, diffraction grating which has been mounted on a real building facade at Toulouse International Airport and a new thin resonant diffraction grating that has been successfully demonstrated on a full scale test base.

MA16 InvScat: Imaging and Inverse Scattering

Propagation/Multi Applications
Room: Bartolomeu Dias (Aud 4)
Chairs: Oleksandr Malyuskin (Ulster University, United Kingdom (Great Britain)), Okan Yurduseven (Queen's University Belfast & Duke University, United Kingdom (Great Britain))
11:10 Sparse Electromagnetic Imaging Using Nonlinear Iterative Shrinkage Thresholding
Abdulla Desmal (Higher Colleges of Technology, United Arab Emirates); Hakan Bagci (King Abdullah University of Science and Technology (KAUST), Saudi Arabia)
A sparse nonlinear electromagnetic imaging scheme is proposed for reconstructing dielectric contrast of investigation domains from measured fields. The proposed approach constructs the optimization problem by introducing the sparsity constraint to the data misfit between the scattered fields expressed as a nonlinear function of the contrast and the measured fields and solves it using the nonlinear iterative shrinkage thresholding algorithm. The thresholding is applied to the result of every nonlinear Landweber iteration to enforce the sparsity constraint. Numerical results demonstrate the accuracy and efficiency of the proposed method in reconstructing sparse dielectric profiles.
11:30 Comparison of Different Reconstruction Algorithms for Image Reconstruction in Metamaterial Aperture Based Imaging System
Okan Yurduseven (Queen's University Belfast & Duke University, United Kingdom (Great Britain)); Jonah Gollub (Duke University, USA); Hayrettin Odabasi (Eskisehir Osmangazi University, Turkey); Mohammadreza Imani (University of Michigan, USA); Guy Lipworth (Duke University, USA); Alec Rose (Evolv Technology, USA); Parker Trofetter and David Smith (Duke University, USA)
We investigate the performance of various image reconstruction algorithms for the design of metamaterial aperture based imaging system. The metamaterial imaging system consists of a transmitting metamaterial aperture panel and a receiving low-gain probe antenna. The imaging of a 3 cm resolution target is performed using a number of reconstruction algorithms, including matched filter (MF), generalized minimal residual method (GMRES), conjugate gradient squares (CGS), and two-step iterative shrinkage/thresholding (TWIST) methods. The differing quality of the resulting reconstructed images is shown.
11:50 Microwave Imaging and Material Characterization Using Resonantly Loaded Apertures
Oleksandr Malyuskin (Ulster University, United Kingdom (Great Britain)); Vincent Fusco (Queen's University Belfast, United Kingdom (Great Britain))
A novel microwave imaging technique based on resonantly loaded apertures is described in this paper. Microwave transmission through the loaded apertures leads to significant near field enhancement and localization in the near field zone which in turn enables subwavelength imaging with very high amplitude and phase resolution contrast (typically more than 10dB and 40 degrees respectively). Additionally, accurate microwave spectroscopic material characterization is possible. Experimental data illustrate the application of the proposed technique to high-resolution microwave imaging of conductive printed elements, dielectric structures, surface defects and biomaterials characterization.
12:10 Polarimetric Target Discrimination for Ultrawideband Radar Imaging
Matthias Röding (Ilmenau University of Technology, Germany); Rudolf Zetik (Fraunhofer Institute for Integrated Circuits IIS, Germany); Reiner S. Thomä (Ilmenau University of Technology, Germany)
A method for characterization of short range radar targets is proposed, that uses information hold by the polarimetric covariance matrix of a range cell. With regard to UWB imaging, a reduction of artefacts in image domain is achieved by filtering radar data with the aim to suppress undesired interferers. The performance is shown with real measurement data and compared to conventional techniques.
12:30 Probe Configuration Study for the Metamaterial Aperture Imager
Okan Yurduseven (Queen's University Belfast & Duke University, United Kingdom (Great Britain)); Jonah Gollub (Duke University, USA); Hayrettin Odabasi (Eskisehir Osmangazi University, Turkey); Mohammadreza Imani (University of Michigan, USA); Guy Lipworth (Duke University, USA); Alec Rose (Evolv Technology, USA); Parker Trofetter and David Smith (Duke University, USA)
A metamaterial imager consists of one transmitting metaimager panel and a collection of broadband receiving probes. Image reconstruction is performed by interrogating a scene with a set of radiative measurement modes encoded in the frequency response of the metamaterial panel. The image quality is a function of the ability of the receiving probes to capture the reflected energy. Here, the number and configuration of the receiving probe antennas is investigated. It is demonstrated that increasing the number of probe antennas and distributing their placement in space increases the number of measurement modes, enhances the image reconstruction for the metamaterial imager. The imaging of a smiley face target is performed using one probe and five probe metaimager configurations and successfully reconstructed images are demonstrated.

Tuesday, April 14 14:00 - 15:00 (Europe/Berlin)

Poster A1: Antennas Poster Session 1

Room: Luís de Camões (Hall 3)
Chairs: David Fernandes (University of Coimbra - Instituto de Telecomunicações, Portugal), Filipa Prudencio (Instituto de Telecomunicacoes, Portugal)
On the Stored and Radiated Energy Density
Lukas Jelinek and Miloslav Capek (Czech Technical University in Prague, Czech Republic)
This contribution reviews and discusses several concepts of stored and radiated energy density of an electromagnetic field. The contribution exposes the most important differences between the up to date definitions and discusses consequences in terms of the energy density of the dominant spherical TE mode.
FDTD-Compatible Green's Function Based on Scalar Discrete Green's Function and Multidimensional Z-Transform
Tomasz P Stefanski (Gdansk University of Technology, Poland)
In this contribution, a new formulation of the FDTD-compatible Green's function based on the scalar discrete Green's function (DGF) is proposed. Recently, the closed-form expression for scalar DGF was derived with the use of the multidimensional Z-transform. Hence, dyadic FDTD-compatible DGF can be computed in the standard 64-bit arithmetic from scalar DGF implemented in the multiple-precision arithmetic. Using the developed formulation, dyadic DGF can be computed efficiently for DGF-FDTD simulations.
A Fast Algorithm for the Analysis of Electrically Large Arrays of Plasmonic Nanoparticles with Aperiodic Spiral Order
Muhammad Zubair (Information Technology University of the Punjab, Pakistan & Singapore University of Technology and Design, Singapore); Matteo Alessandro Francavilla (Istituto Superiore Mario Boella, Italy); Marco Righero (LINKS Foundation, Italy); Giuseppe Vecchi (Politecnico di Torino, Italy); Luca Dal Negro (Boston University, USA)
This work presents a fast solver for analysis of electromagnetic scattering from plasmonic arrays of metallic nanoparticles with aperiodic spiral order. The reported method extends the integral equation fast Fourier transform (IE-FFT) algorithm to the method of moments solution of PMCHWT integral equation for aperiodic homogenous dielectric arrays. The algorithm relies on the interpolation of Greens function by Lagrangian polynomials on a uniform Cartesian grid. Hence, the matrix-vector product in the iterative solver can be computed via the fast Fourier transform. The memory requirement and the computational complexity of the algorithm tend to stay close to O(N) and O(NlogN), respectively, where N is the number of unknowns. Some numerical examples are included, which illustrate the accuracy and capability of the present method.
Investigation and Comparison Between Radiation Center and Phase Center for Canonical Antennas
Casimir Ehrenborg (KU Leuven, Belgium); Jonas Fridén (Ericsson AB, Sweden); Gerhard Kristensson (Lund University, Sweden)
Radiation center, corresponding to minimized angular momentum, and traditional phase center calculations are compared for a set of canonical antenna elements. By using simulation results, the exact phase reference position of the complex-valued far-field pattern is considered exactly known. Influence of user inputs, e.g. angular truncation, on traditional phase center results are investigated. In addition, an analytic method by Muehldorf is used. Adherence of radiation center to traditional phase center behavior is discussed. For the first time the ability of the radiation center algorithm to minimize the phase variations in the main lobe is demonstrated.
Spherical Model for Efficient Parametric Analysis of Implanted Antennas in WBAN Applications
Marko Bosiljevac (University of Zagreb, Croatia); Anja K. Skrivervik (EPFL, Switzerland); Zvonimir Sipus (University of Zagreb, Croatia)
Implanted antennas are an important part of a growing family of various Wireless Body Area Networks (WBAN). Understanding the radiation characteristics of these antennas when they are placed inside a finite lossy host medium is crucial for further development and optimized design of these networks. In this paper we focus on a simplified spherical multi-shell model of the lossy body. Using separate spherical mode decomposition of the fields for the implanted antenna and the body problems we have developed an efficient technique that allows us to study radiation for various positions and orientations of the source. The results of this analysis will give better insight into potential problems and benefits of placing implanted antennas into certain layers of the body.
Method of Moments Analysis of Modulated Metasurface Antennas
David González-Ovejero (Centre National de la Recherche Scientifique - CNRS, France); Enrica Martini, Francesco Caminita, Maddalena Violetti and Stefano Maci (University of Siena, Italy)
This paper shows that the method of moments (MoM) analysis of metasurface (MTS) antennas may be carried out by introducing the effect of the MTS as a jump impedance boundary condition (IBC) in the integral equation. Moreover, the use of a novel class of entire-domain basis functions with analytical spectrum allows for a closed-form evaluation of the MoM impedance matrix's entries. The proposed set of basis functions also represent the surface current density on the MTS in an efficient manner, leading to a significant reduction in the number of unknowns which enables a direct solution. These features allow one to carry out a direct solution for problems with a diameter of up to $15$ wavelengths in less than one minute using a conventional laptop.
Performance of a Novel Miniature Antenna Implanted Into the Human Trunk for Medical Telemetry Applications
Sofia Bakogianni and Stavros Koulouridis (University of Patras, Greece)
In this study, the performance of an implantable miniature planar dipole antenna designed for integration into wireless biomedical devices is investigated. The proposed antenna, exhibiting dimensions of 19.4 * 2 * 0.254 mm3, operates in the Medical Implant Communication Service (MICS) frequency band (402-405 MHz). Numerical analysis with regard to antenna resonance and radiation characteristics is, initially, conducted inside a homogeneous 2/3 muscle-equivalent phantom. Based on the initial computational results, the dipole antenna is, subsequently, embedded into the trunk of a high-resolution anatomical model in order to assess antenna functionality under specific implantation scenario. Specific Absorption Rate (SAR) and communication link estimation within the realistic complex tissue environment is, also, carried out.
An Overview of Stored Electromagnetic Energy
Mats Gustafsson (Lund University, Sweden)
Evaluation of the stored energy is instrumental for estimation of antenna Q-factors. Here, we present an overview of methods to define and evaluate the stored energy and the associated Q-factor. The stored energy can be evaluated using either the; electromagnetic fields, current densities, impedance matrices, or circuit models. Evaluation of the stored energy is also essential for current optimization with the associated physical bounds.
Application of the Hybrid Projective Methods for Determining Effective Permittivity of Artificial 1D- And 2D-Periodic Dielectric Layers
Olga Smolnikova (Company Radiophyzika, Russia); Sergei P. Skobelev (Radiophyzika, Russia)
The effective permittivity of a planar dielectric layer formed by 1D- and 2D-periodic structures with dielectric cylindrical elements of rectangular cross section is determined by hybrid projective methods with using the concept of a layer of half-wavelength thickness. Some numerical results are presented and compared to the results based on analytical expressions corresponding to the quasi-static approximation.
Computational Electromagnetic Modeling is Key in Objective Control of Hyperthermia
Gerard C. van Rhoon (Erasmus MC Cancer Institute, The Netherlands); Margarethus M. Paulides (Eindhoven University of Technology, The Netherlands); Tomas Drizdal (Czech Technical University in Prague, Czech Republic)
Confining treatment to the tumor to improve therapeutic outcome and reduce toxicity, is a hot issue in cancer research. Hyperthermia is recognized as a strong sensitizer for radiotherapy and chemotherapy enhancing tumor control without increasing toxicity. Today's electromagnetic hyperthermia systems heat large tissue volumes with limited ability to selectively heat the tumor. Fortunately, tremendous improvements in 3-dimensional electromagnetic & temperature modelling provide an exciting opportunity to design advanced multi-element electromagnetic applicator systems. Together with feedback control using MR non-invasive thermometry and smart E-field sensors, this paves the way for selective tumor heating and potentially prescription of a thermal dose.
Modal Analysis of Non-Separable Outer-Boundary Cavities Via Spherical Vector Wave Functions
Theodoros Kaifas (Aristotle University of Thessaloniki, Greece); Elias E Vafiadis (Aristotle University of Thessaloniki & Physics Department, Greece); Xenofon Mitsalas (Democritus University of Thrace, Greece); John Sahalos (Aristotle University of Thessaloniki, GR, Thessaloniki, Greece & University of Nicosia, CY, Nicosia, Cyprus); George A. Kyriacou (Kimmeria Campus, Greece & Democritus University of Thrace, unknown)
A three dimensional Mode Matching/ Collocation technique is proposed in the current work for the analysis of a general cavity loaded with a spherical in-homogeneity. Analytical electromagnetic field eigen-solutions expressed in terms of spherical wave functions are utilized for the field expansions. The boundary conditions on the outer surface are enforced through the collocation method. Analytical results are obtained for both the source driven problem and the corresponding eigen-problem, i.e. the eigenfunctions of the whole inhomogeneous geometry are obtained. The proposed theory will be utilized modelling biomedical structures and especially in microwave ablation. The contribution of the current work is the use of entire domain basis functions that provide performance improvements especially for electrically medium to large domains. Results, including finite domains, following coordinate or non-separable surfaces, inside spheroids, paraboloids and elliptic cones, have been extracted and the performance of the method with respect to computational resources will be reported.
Verification & Validation Benchmarks for Assessing and Demonstrating the Credibility of Computational Medical Device Evaluation
Esra Neufeld (IT'IS Foundation, ETH Zurich, Switzerland); Niels Kuster (IT'IS Foundation, ETH Zurich)
Computational modeling is a powerful tool in the development, the safety and efficacy assessment of medical devices, and medical treatments. However, computational models must be properly verified and validated before they can be applied. Verification and validation approaches stemming from the engineering community are not readily applicable to problems involving the human body and in vivo effects. The issues, current methodology, needs for adequate benchmarks (analytical, computational, and experimental), and uncertainty assessment will be discussed using examples from MRI safety and neuroprosthetics.
Optimal Aperture Distribution for Maximum Power Transfer in Planar Lossy Multilayered Matters
Aidin Razavi (Ericsson Research, Sweden); Rob Maaskant (CHALMERS, Sweden); Jian Yang (Chalmers University of Technology, Sweden); Zvonimir Sipus (University of Zagreb, Croatia); Mats Viberg (Blekinge Institute of Technology, Sweden)
We combine array-signal-processing and spectral domain techniques to determine the optimal aperture current distribution that maximizes the power coupling between two antenna apertures which are located on opposing sides of a multilayered lossy structure in near-field. The resulting optimal distribution can be used as reference in the design of antennas for near-field applications such as detection of foreign objects in lossy media, wireless charging of implant batteries or near-field communications with the implant.
On an Indirect Boundary Element Method for the Anisotropic EEG Forward Problem
Axelle Pillain, Lyes Rahmouni and Francesco Andriulli (Ecole Nationale Superieure des Telecomunications de Bretagne, France)
This paper introduces a boundary element methodfor the electroencephalography forward problem that can handlethe anisotropic conductivities of the cerebral medium. Here, theharmonic part of the solution is added piecewise to enforce theboundary conditions. Indeed, for the multilayer anisotropic EEGforward problem, the harmonicity cannot be defined in a globalway. An indirect approach enables to achieve the goal and toavoid the pitfall of a possible misconception in the generalisationof the existing isotropic formulations. The solution presented hereis based on a Single Layer representation of a piecewise harmonicfunction and gives promising numerical results.
Modeling an Extremely Thin Material Sheet Using the Finite-Difference Time-Domain Method
Yaxin Yu (Chang'an University & College of Electronic and Control Engineering, China); Ching Eng Png (A*STAR Institute of High Performance Computing, Singapore)
We report in this paper a finite-difference time-domain algorithm to efficiently simulate a super thin material sheet to avoid the usage of an extremely fine mesh required by traditional electromagnetic solvers. As such, the computational cost can then be dramatically reduced. In this algorithm, the dispersion and non-dispersion characteristics of the layer are both included in simulations. The technical details of the model, as well as some numerical results, are to be discussed during the presentation.
Stability and Accuracy Analysis of Several FDTD Schemes for Modeling Tellegen Media
Ana Grande (University of Valladolid, Spain); José Pereda (University of Cantabria, Spain); Ismael Barba, Ana C. Lopez-Cabeceira and José Represa (University of Valladolid, Spain)
The magnetoelectric coupling that appears in the constitutive relations of Tellegen media makes formulating unconditionally stable finite-difference time-domain (FDTD) extensions a challenging problem. In this letter, we present an alternating direction implicit (ADI)-FDTD approach for modeling transient wave propagation in Tellegen media. In the proposed formulation, the discretization of the governing equations is performed introducing weighted average parameters. The numerical features are then carefully examined and the weighted discretization parameters conveniently chosen to yield an unconditionally stable scheme. Moreover, the resulting approach presents second order accuracy and preserves the tridiagonal structure of the data matrices. Finally, the numerical dispersion relation is given in a closed-form. The new method has been validated by means of numerical experiments and has shown good agreement.
Full-Wave Modeling of Stochastic Trees for Radar Cross Section Calculation
Branko Mrdakovic (WIPL-D, Serbia); Dragan I. Olcan and Branko Kolundzija (University of Belgrade, Serbia)
We outline an approach for full 3 D electromagnetic analysis of stochastically generated trees. The approach starts from the stochastic model of trees and import them into CAD tool, which is coded to do the specifically tailored quad meshing. The final dielectric model is simulated using a desktop computer equipped with three graphical processing units. We a code based on method of moments with surface integral equations, higher order basis functions and Galerkin testing procedure to illustrate the approach and its efficiency.
A Tilted Subgrid for Two Dimensional FDTD
Chris Railton (University of Bristol & Communications Systems and Networks group, United Kingdom (Great Britain))
Although the Finite Difference Time Domain (FDTD) method is well established for addressing a wide variety problems including the characterization of antenna arrays, a long standing challenge is to reduce discretization errors while avoiding the use of impractically large numbers of cells, particularly when the structure is large and contains regions of fine detail. One solution is to use subgrids. In most published work, Cartesian subgrids are proposed which are in the same orientation as the main grid. However there is considerable benefit to allowing for the subgrid to be tilted. In this work, a method for introducing a tilted subgrid into the 2D FDTD mesh is presented and its effectiveness, accuracy and stability is demonstrated using examples. The method is readily extendable to a full 3D implementation.
Field-Circuit Co-Simulation of the Marx Generator
Qian Xu, He Jiang, Yi Huang, Jiafeng Zhou and Chaoyun Song (University of Liverpool, United Kingdom (Great Britain)); Lei Xing (Nanjing University of Aeronautics and Astronautics, China)
A full wave field-circuit co-simulation method is employed to characterise the time domain behaviour of the Marx generator. Radiation and conduction effects are fully considered. Results from the co-simulation and the circuit simulation are compared; it can be found that the field-circuit co-simulation provides complete information of the system which includes the radiation effect and the mutual coupling in space. The radiated field strength is important when designing the shielding room which is used to protect the measurement instruments in practice.
Acceleration of the DGF-FDTD Method on GPU Using the CUDA Technology
Tomasz Dziubak (Gdansk University of Technology, Poland); Michal Wiktor (Medical University of Gdansk, Poland); Slawomir Orlowski and Tomasz P Stefanski (Gdansk University of Technology, Poland)
We present a parallel implementation of the discrete Green's function formulation of the finite-difference time-domain (DGF-FDTD) method on a graphics processing unit (GPU). The compute unified device architecture (CUDA) parallel computing platform is applied in the developed implementation. For the sake of example, arrays of Yagi-Uda antennas are simulated with the use of DGF-FDTD on GPU. The efficiency of parallel computations is presented as a function of the number of current elements in such wire antennas. The speedup of the developed implementation approaches maximally 10 relative to the code executed on a multicore central processing unit (CPU). Furthermore, the hybrid solver combining FDTD and its convolution formulation based on DGF was implemented on a heterogeneous CPU-GPU system, facilitating our research on the DGF-FDTD method.
Field Computations Through the ACA Algorithm
Rob Maaskant (CHALMERS, Sweden); Vito Lancellotti (Eindhoven University of Technology, The Netherlands)
The adaptive cross approximation algorithm is invoked for the fast construction of the MoM coupling matrix between the basis functions for the currents and a set of auxiliary ones that test the field in the near or far field of the radiating structure. Once the ACA coupling matrix is constructed, the far and near fields from currents are obtained directly through matrix-vector products. The method is particularly fast when the fields are smoothly varying over their sampling domain and when they need to be computed for many current distributions, e.g., for sets of macro basis functions arising in several domain decomposition methods.
Evaluation of Near-Singularity Cancellation Quadrature Schemes for the Green Function Gradient on Higher-Order Triangles
Matthys M. Botha (Stellenbosch University, South Africa)
Efficient evaluation of near-singular surface integrals is important to the efficient implementation of the MoM. The focus here is on the Green function gradient kernel. A recently-proposed near-singularity cancellation quadrature scheme (AD-R1-L-AS2) is compared to other three-subdomain splitting methods available in the literature. The main benefit of the simple three sub-triangle splitting approach is that it allows accuracy control via a single parameter. The effect of a flat versus curvilinear integration domain is investigated as well as the effect of switching between the static and dynamic versions of the Green function gradient. The paper shows that the ADR1-L-AS2 scheme is suitable for the cases considered and that it performs better it the tests conducted, than the other schemes considered.
Novel Source-to-Source Compiler Approach for the Automatic Parallelization of Codes Based on the Method of Moments
Hipólito Gómez-Sousa (Northeastern University, USA); Manuel Arenaz (University of A Coruña, Appentra Solutions S. L., Spain); Oscar Rubiños-López (University of Vigo, Spain); Jose Martinez Lorenzo (Northeastern University, USA)
In computational electromagnetics, surface integral equation (SIE) formulations are widely used to predict the electromagnetic scattering from arbitrary structures. These SIE formulations are discretized into a matrix form by the well-known method of moments (MoM). Up to now, the lack of proper compilers made it necessary for the MoM codes to be parallelized by hand in order to obtain reasonable performance on present computers. Since MoM codes are very complex, this manual parallelization is always a tedious error-prone task. In this paper we present a new parallelizing compiler, called Parallware, based on a novel disruptive technology for the automatic parallelization of sequential codes written in the C programming language. We show through simulation performance results that, starting from real sequential MoM codes for penetrable scatterers, this new compiler provides efficient parallel MoM codes automatically.
Numerical Analysis of Avionic Grounding Structures with Surface PEEC Formulation
Mauro Bandinelli and Alessandro Mori (IDS Ingegneria Dei Sistemi S. p. A, Italy); Giulio Antonini (Università degli Studi dell'Aquila, Italy); Daniele Romano (University of L'Aquila, Italy); Gian Marco Sammarone (IDS Ingegneria dei Sistemi S.p.A., Italy)
The numerical simulation of complicated grounding structures at low frequency – from about a hundred Hertz to some MHz – is required in several cases, for instance for the modelling of direct and indirect effects of lightning on aircraft. The Partial Element Equivalent Circuit (PEEC) methodology allows the mitigation of the low frequency ill conditioning problems of the canonical Method of Moments, and also allows the excitation of the structure under analysis by direct injection of an external electrical current. This paper describes the use of a surface formulation of the PEEC methodology, including the use of an accelerated iterative solver to allow the analysis of large models.
Study of Annular Ring Patch Antennas on Anisotropic Substrates by WCIP Method
Valdemir Neto (Universidade Federal Rural do Semi-Árido, Brazil); Cristhianne Vasconcelos and Maria Albuquerque (Federal University of Rio Grande do Norte, Brazil); Adaildo G D'Assunção (Federal University of Rio Grande do Norte & UFRN - CT - DCO, Brazil)
A Wave Concept Iterative Procedure (WCIP) based on transverse waves formulation is presented. This method is applied to analyze annular microstrip patch antennas on anisotropic substrates. The use of FFT algorithm to define a fast modal Fourier transform results in accurate solutions with significant savings in computation time and memory requirements. WCIP results are compared with the HFSS simulation data and a good agreement is verified.
The Finite Difference Frequency Domain Method for the Eigenanalysis of Open Periodic Structures
Christos S Lavranos (Democritus University of Thrace, Greece); Panagiotis Theofanopoulos (Arizona State University, USA); Kyriakos Zoiros (Democritus University of Thrace, Greece); Gérard Granet (Blaise Pascal University, France); George A. Kyriacou (Kimmeria Campus, Greece & Democritus University of Thrace, unknown)
The eigenanalysis of periodic stuctures is presented herein by extending our previous two – dimensional curvilinear frequency domain finite difference domain (FDFD) toward the eigenanalysis of open/radiating periodic structures. Initially, the open/radiating structures are simulated using the Perfectly Matched Layer (PML), while later Mur's Absorbing Boundary Conditions (ABC) will be introduced within the FDFD formulation. In parallel, the periodicity of the structure is accounted through the enforcement of Periodic Boundary conditions (PBC) within the FDFD formulation. The periodicity can be either in one or in two dimensions, while out of plane propagation is assumed along the third dimension with propagation constant different from zero.
Comparison of a Fast Probabilistic Propagation Model Against an Analytical Computational-EM Model and Measurements for the Evaluation of Passive RFID Systems
Antonis G Dimitriou and Achilles D. Boursianis (Aristotle University of Thessaloniki, Greece); Ioannis Markakis (Aristotle Uniersity of Thessaloniki, Greece); Stavroula Siachalou and Theodoros Samaras (Aristotle University of Thessaloniki, Greece); John Sahalos (Aristotle University of Thessaloniki, GR, Thessaloniki, Greece & University of Nicosia, CY, Nicosia, Cyprus)
This paper presents the comparison of a fast probabilistic propagation model against an analytical computational EM model and measurements performed for the evaluation of passive RFID systems. The results of the probabilistic model compared to the ones of the analytical model, as well as to the measurements, are in fairly good agreement.
Rigorous Analysis of Deformed Nanowires Using the Multilevel Fast Multipole Algorithm
Bariscan Karaosmanoglu, Akif Yilmaz and Ozgur Ergul (Middle East Technical University, Turkey)
We present accurate full-wave analysis of deformed nanowires using a rigorous simulation environment based on the multilevel fast multipole algorithm. Single nanowires as well as their arrays are deformed randomly in order to understand the effects of deformations to scattering characteristics of these structures. Results of hundreds of simulations are considered for statistically meaningful analysis of deformation effects. We show that deformations significantly enhance the forward-scattering abilities of single and arrays of nanowires, where the enhancement factor of an array depends on the number of elements.
Comparison of 3D and 2D Method to Study the Propagation in a U-shaped Valley
Pierrick Hamel (IEEA, France); Jean-Pierre Adam (CEA, France); Yannick Béniguel (IEEA, France); Jean-Christophe Joly (CEA, France)
This paper presents 5 different electromagnetic methods, asymptotic and exact, in 3 dimensions and in 2 dimensions, to simulate the radiation of an antenna in a U-shaped valley. The precision of the result and the calculation time are compared for each methods.
Accelerating Frequency Selective Surface Simulations: An Equivalent Circuit Method Versus Computational Electromagnetics Software - Limits and Further Developments
Mélusine Pigeon (Queen Mary, University of London); Rostyslav Dubrovka, Robert Donnan and Theo Kreouzis (Queen Mary, University of London, United Kingdom (Great Britain))
This paper outlines improvements required in the modal decomposition equivalent circuit modelling (MDECM) method to simulate complex periodic structures at high frequencies as THz. It discusses initial approximations used by the method and whether they should be retained. Finally, in comparing the results of Modal Decomposition Equivalent Circuit Method (MDECM) to commercial computational electromagnetic (CEM) software, a measure is made of simulation speeds and match of results for both a free and capacitively-loaded slot-ring.
Comments on the Phase Center Computation for Ka-band Planar Lens-Antenna Feeders
Pedro Robustillo (École Polytechnique Fédérale de Lausanne, Switzerland); Joana Silva (Huber+Suhner, Switzerland); Jorge R. Costa (Instituto de Telecomunicações / ISCTE-IUL, Portugal); Carlos A. Fernandes (Instituto de Telecomunicacoes, Instituto Superior Tecnico, Portugal); Juan R Mosig (Ecole Polytechnique Federale de Lausanne, Switzerland)
This paper presents a modified methodology to compute the phase center of planar antennas. It is especially well suited for low-profile geometries without axial symmetry that are currently being proposed as feeder systems for Ka-band lens antennas. By taking into account new features, such as large spherical surface consideration and dual electric field components, this modified algorithm results in improved designs for complete Ka-band, lens-based systems showing consistently an enhanced gain.
Spatiotemporal Slabs in Order to Improve Performance in 2D FDTD
Juan Giraldo and Néstor M. Peña (Universidad de los Andes, Colombia); Michel Ney (IMT Atlantique, France)
Among the techniques widely used in CEM (Computational Electromagnetics), the FDTD method (Finite-Difference Time Domain) is one of the most demanding in computational resources. Despite the computing power available today on a personal computer, industry demands the analysis of large and complex models to be used in several electromagnetics applications. The algorithm of the FDTD method is based on the Yee cell. The Yee cell is a space-time discretization of Maxwell's equations. The performance of the FDTD method is limited by the bandwidth of the traditional algorithm. When describing the dynamics of Maxwell equations through slabs or spatiotemporal macro-cells larger than the Yee cell, the re-use of calculated fields is increased. In consequence, the performance of traditional FDTD algorithm is also increased.
Statistical Modeling of Antennas Via a Generalized Stochastic-FDTD Method
Athanasios N. Papadimopoulos, Georgios G. Pyrialakos and Antonios X. Lalas (Aristotle University of Thessaloniki, Greece); Theodoros T. Zygiridis (University of Western Macedonia, Greece); Nikolaos V. Kantartzis (Aristotle University of Thessaloniki, Greece); Christos S. Antonopoulos (Aristotle University of Thessaloniki & ELKE AUTH, Greece); Thomas F. Eibert (Technical University of Munich (TUM) & Chair of High-Frequency Engineering (HFT), Germany); Theodoros D. Tsiboukis (Aristotle University of Thessaloniki, Greece)
The consistent analysis of complex antenna setups with statistically varying media attributes is performed in this paper through a 3-D curvilinear stochastic finite-difference time-domain technique. The new method generalizes the concept of covariant/contravariant metrics for curved structures and derives the mean value and standard deviation of field components in a single run. Also, for the acceleration of the resulting simulations, all codes are developed in terms of graphics processor units and parallel programming. The profits of the proposed algorithm over multiple-realization Monte-Carlo schemes are certified via comparisons from circular- and trapezoidal-toothed log-periodic antennas with various realistic uncertainties in their materials.
Detuning Effect Study of High-Q Mobile Phone Antennas
Pevand Bahramzy (Aalborg University & Intel Mobile Communications, Denmark); Gert Pedersen (Aalborg University, Denmark)
This study investigates high-Q antennas performance when placed in proximity of the user. The investigations are done through experimental measurements using standardized head phantom and hand. The study shows that low-Q antennas detune more than high-Q antennas. However, the drop in efficiency, when placed next to the user, is similar for both antennas.
Frequency Tunable and Circular Polarization Switchable Antenna Using Dual Polarized Active Artificial Ground Structure
Bin Liang and Benito Sanz-Izquierdo (University of Kent, United Kingdom (Great Britain)); Edward Parker (The University of Kent, United Kingdom (Great Britain)); John Batchelor (University of Kent, United Kingdom (Great Britain)); Jungang Miao and Ming Bai (Beihang University, China)
This paper presents a frequency and polarization reconfigurable circular polarized (CP) antenna using active artificial ground (AG) structure. The active AG structure offers independent and symmetrical tuning capability of the reflection phases for dual polarized incident waves. By combining the AG structure with a wideband coplanar waveguide fed monopole antenna, and tuning the capacitances of the varactor diodes on the AG structure, CP wave is dynamically realized at any desired frequency over a wide band between 1.15-1.60GHz. At each frequency, the CP state is switchable between left hand CP and right hand CP, by simply swapping the capacitances of varactors controlling the reflection phases of the two orthogonal polarized waves. The antenna covers the frequencies of all operational and in-preparation satellite navigation systems, including GPS, GLONASS, Beidou and Galileo.
On the Design of Generic Matching Networks in Reflective-Type Phase Shifters for Antennas
Pablo Alcon (Universidad de Oviedo, Spain); Nuria Esparza, Luis Fernando Herran and Fernando Las-Heras (University of Oviedo, Spain)
In this paper, an analysis of improvement in the performance of a reflective–type phase shifter through the addition of a matching network is presented, taking into account both the phase range and the insertion loss variation. By reducing the complexity of the matching network's analysis and narrowing it down to two parameters, an easier to read set of solutions is obtained for any given reflective load. Finally, a prototype was manufactured and measured using one of the matching points procured with the described method, increasing the phase shifter range at 9GHz from 56◦ to 242◦, with an insertion loss variation of 6.18dB.
Influence of Complementary Split Ring Resonator Dimensions in Ultra Wideband Microstrip Patch Antenna
Isaac B. T. da Silva (Federal Rural University of Semi-Arid); Humberto Andrade (Federal University of Semiarid Region & DCAT, UFERSA, Brazil); José Lucas da Silva Paiva (Universidade Federal Rural do Semi Árido, Brazil); Humberto C. C. Fernandes (Federal University of Rio Grande do Norte, Brazil)
This paper has the objective of study the influence of complementary split ring resonator dimensions in an UWB microstrip patch antenna. A good agreement between capacitive effect and the different dimensions used could be observed and an antenna with an effective frequency range filter could be achieved to prevent 802.11a and 802.11n interference, as part of X band frequency.
Application of Transformation Electromagnetics Concept to Delocalize Emissions
Paul-Henri Tichit (IEF - Université Paris Sud, France); Jianjia Yi (Key Laboratory of Integrated Services Networks, Xidian University, China); Shah Nawaz Burokur (LEME, France); André de Lustrac (Institut d'Electronique Fondamentale - Université Paris-Sud, France)
The emission of a radiating source is virtually delocalized through the use of transformation electromagnetics concept. The electromagnetic device able to perform such a transformation is obtained by a space compressing followed by a space expansion. Theoretical formulations are presented and full wave numerical simulations are performed to present the approach.
Design of Modulated Metasurface Antennas Based on Elliptical Patches
Marco Faenzi (University of Siena, Italy); Mario Junior Mencagli (University of North Carolina at Charlotte, USA); Enrica Martini (University of Siena, Italy); David González-Ovejero (Centre National de la Recherche Scientifique - CNRS, France); Stefano Maci (University of Siena, Italy)
This paper presents the design of modulated metasurface (MTS) antennas based on elliptical patches. An effective analysis procedure is employed to accurately and efficiently generate multiparametric databases for elliptical patches MTS, in order to exploit all the available degrees of freedom and to obtain the maximum flexibility in the design.
A Triple-Slot Active Reflectarray Cell Using a Ferroelectric Capacitor
Kevin Nadaud (IETR/University of Nantes, France); Raphael Gillard (IETR & INSA, France); Erwan Fourn (INSA of Rennes & IETR, France); Caroline Borderon (IETR/University of Nantes, France); Hartmut Gundel (IREENA, France)
A tunable reflectarray phase-shifting cell, designed for a resonance frequency of 5.5 GHz, is presented. The cell is based on a triple-slot topology and loaded by a ferroelectric thin film capacitor with 60% tunability under 400 kV/cm bias electric field. The use of three slots allows reducing the losses and increasing the bandwidth of the cell. The cell provides 270 degrees of phase range with a maximum of 6 dB loss in the band.
Magnetic Near-Field Imaging with a Racemic Array of Helical-Shaped Metallic Wires
Tiago Morgado (Instituto de Telecomunicações and University of Coimbra, Portugal); Mario Silveirinha (Universidade de Lisboa - Instituto de Telecomunicações, Portugal)
We demonstrate that a racemic array of helical-shaped metallic wires may behave as the magnetic analog of the conventional wire medium formed by parallel straight metallic wires. It is shown that under transverse electric (TE) excitations, such metamaterial supports a quasi-TEM dispersionless mode with respect to the transverse wave vector component. Exploiting this property, we show that this metamaterial may enable the channeling of the near-field details of TE polarized waves.
Half-massive Ceramics for Antenna Downsizing: Improvement of a Smart Magneto-Dielectric Material with Matching Permeability and Permittivity, and with Enhanced Low-Loss Frequency Range
Emmanuel Le guen (LabSTICC/IETR, France); Jean-Luc Mattei (LabSTICC); Anne-Claude Tarot (University of Rennes1, IETR, France)
Complex permeability and permittivity of Ni0.5Zn0.3Co0.2Fe1.98O4-x half-ceramic ferrites (porosity ~50%), got from various annealing temperature TA (500°C, 800°C, 900°C), are measured and compared. Their characteristic impedance Z, magnetic and dielectric loss tangents are presented. Bandwidth BW and radiation efficiency η values of patch antennas are got through numerical simulations and compact formulations. The value of the annealing temperature used for the substrates determines those of BW and η. BW and η are themselves used as criteria to decide which one among the substrate is proper to be used at given frequency. It is concluded that whereas the sample annealed at 500°C is far to meet the required properties in reason of detrimental magnetic losses, the half massive ceramics got after annealing at TA=800°C and 900°C show appropriate performances for further applications. The electromagnetic properties of half ceramics materials sound to be very competitive at frequencies up to 0.8GHz.
Composite Defect-Mode Superstructures and Wideband EBG Resonator Antennas
Raheel M Hashmi (Macquarie University & IEEE, Australia); Basit Ali Zeb (Macquarie University, Australia); Karu Esselle (University of Technology Sydney, Australia)
We propose two EBG structures made out of multi-layer dielectric slabs to enhance the bandwidth of EBG resonator Antennas (ERAs). These multi-layer structures are designed to achieve wide defect-mode bandwidths. Wide defect-modes are created by optimizing the permittivity and thickness of the individual slabs, as well as the inter-slab separations. Using these EBG structures as ERA superstrates and truncating them appropriately to a finite size, two ERAs were designed. They exhibit pattern bandwidths nearly twice as wide as the classical ERAs. 3dB directivity bandwidths of 14.1% and 19.3% with a maximum directivity of 17.5 dBi and 18.7 dBi, respectively, were measured for the two ERA prototypes. The lateral dimensions of the ERA superstrates are 1.5 x 1.5 sq. wavelengths which represent more than 90% reduction in superstrate area when compared with classical ERAs. Small size and simple configuration make these ERAs very suitable for high gain millimeter wave applications.
RF Sensor Based on Gap Waveguide Technology in LTCC for Liquid Sensing
Cristina Arenas-Buendia (Télécom Bretagne & Universidad Politécnica de Valencia, France); Francois Gallée (Télécom Bretagne, France); Alejandro Valero-Nogueira (Universidad Politécnica de Valencia, Spain); Christian Person (Lab-STICC/MOM UMR CNRS, France)
This paper presents a new concept based on the Gap Waveguide topology realized in LTCC (Low Temperature Co-fired Ceramic) technique for microfluidic applications. The proposed structure consists on a Gap Waveguide structure acting as a resonator. The interaction between the electric field and the liquid under test translates into predictable relationship between the characteristics of the resonator (resonant frequency, Q factor) and the complex permittivity of the fluid. This work provides new applications on the Gap Waveguide concept relative to the detection and the exploration of microfluidic applications. Moreover, an improvement in the detection of the sensibility compared to other topologies like Substrate Integrated Cavity has been done.
Wideband High-Impedance Surface Reflector for Low-profile High-Gain UHF Antenna
Nora Mohamed Mohamed-Hicho (Universidad Politécnica de Valencia, Spain); Eva Antonino-Daviu (Universitat Politècnica de València, Spain); Marta Cabedo-Fabrés (Universidad Politécnica de Valencia, Spain); Miguel Ferrando-Bataller and Daniel Sánchez-Escuderos (Universitat Politècnica de València, Spain)
A novel low-profile high-gain UHF antenna for Digital Television (DTV) is presented using an appropriately designed wideband High-Impedance Surface (HIS) reflector. The proposed design is an improvement of the structure presented in previous work. The effect of an air gap between the HIS substrate and its back ground plane is investigated in an effort to produce high-gain, low-profile and lightweight structure. Low-cost substrates are employed in the design, rigid PVC for the antenna and foamed PVC for the artificial ground plane. PVC substrate is ecologic, recyclable, long lasting and cheap. A microstrip-fed monopole mounted on the proposed HIS reflects effectively in phase over a bandwidth of about 56%. Hence, significant enhancement in antenna gain has been achieved, around 7 dBi peak gain with respect to the simple monopole. The composite structure is very compact (total height is 0.098λ). Details of the proposed antenna design and simulation results are described.
Reconfigurable High-Impedance Metasurfaces with Interwoven Conductor Unit Cell Layouts
Andrea I Vallecchi (University of Oxford, United Kingdom (Great Britain)); Richard Langley (University of Sheffield, United Kingdom (Great Britain)); Alex Schuchinsky (University of Liverpool, United Kingdom (Great Britain))
Switchable and tunable high impedance metasurfaces (HIMSs) formed by frequency selective arrays with periodic patterns of interwoven planar conductors backed by a grounded dielectric slab are developed. Reconfigurability of the HIMSs is achieved by incorporation into the frequency selective surfaces (FSSs) of either pin or varactor diodes. A distinctive feature of the presented architectures is that the biasing circuitry is fully integrated into the FSS elements. This results in much simpler HIMS topologies without additional bias wiring that usually cause parasitic scattering and deteriorate the HIMS response at oblique incidence. Similarly to their passive counterparts, these reconfigurable HIMSs exhibit bandwidth similar to that of square patch HISs but with an order of magnitude smaller unit cells that enables dramatic enhancement of the polarisation and angular stability. Furthermore, the proposed active HIMSs feature switchable high and low impedance reflection characteristics and capability for independent switching or phase tuning of the two orthogonally polarized reflected waves with potential for polarization control and rotation.
Broadband Circular-polarization Through Optically Active V-shape Chiral Metamaterial
Rajkumar Jaiswar (Université Catholique de Louvain, Belgium); Isabelle Huynen (Université catholique de Louvain, Belgium)
Optically active cross polarization converter formed by V-shaped metallic resonator (VSR) shows high rate of polarization conversion efficiency in multiple frequency bands as demonstrated numerically. Importantly, VSR chiral metamaterial has shown broadband frequency regime for circularly polarized wave and near-zero ellipticity for linear EM-wave propagation. The giant optical activity in metal-dielectric composite structure arises due to the strong cross-coupling between the electric and magnetic dipoles resulting in strong rotatory power. The mechanism of cross coupling is understood based on surface current distribution on the patterned metallic inclusions.
C-band Parallel Coupled Bandpass Filter with Harmonic Suppression Using Open Stub and CSRRs
Azzeddin Naghar (department of Teoría de la Señal y Comunicaciones, University of Vigo, Spain); Ana Alejos (Universidade de Vigo, Spain); Francisco Falcone (Universidad Publica de Navarra, Spain); Manuel García Sánchez (Universidade de Vigo, Spain); Otman Aghzout (ENSA Tetouan - UAE, Morocco)
Design and implementation of broadband microwave parallel coupled microstrip bandpass filter PCMBPF for C-band applications with suppression of second harmonic frequencies is demonstrated in this paper. This suppression is achieved by separately embedding open stubs and complementary split ring resonators, allocated in and below the 50 Ω transmission line, respectively. Good performance is obtained and comparisons are shown in terms of rejection level and insertion losses of the filter response. Both proposed techniques were numerically analysed and easily integrated without increasing the filter size. The filters were simulated using CST MWs and fabricated on Roger RT/Duroid RO6010 substrate with relative permittivity of 10.2 and dielectric thickness of 1.27 mm.
Novel 3D Printed Synthetic Dielectric Materials for Antenna Applications
Shiyu Zhang, Chinwe C Njoku, William Whittow and J (Yiannis) Vardaxoglou (Loughborough University, United Kingdom (Great Britain))
This paper presents different dielectric properties of air filled synthetic substrates fabricated using 3D printing. Non-solid dielectric substrates with air void inclusions are printed in one-step process. Mechanical machining and assembly are not required to fabricate these non-solid substrates with customised internal voids. The permittivity and loss tangent of a given sized substrate can be changed by the control of printed infill patterns and air volume fractions.
A Partially Complementary Chiral Metamaterial Based on a Four-Cranks Resonator
Ismael Barba, Ana Grande and Ana C. Lopez-Cabeceira (University of Valladolid, Spain); Gregorio Molina-Cuberos (University of Murcia, Spain); José Represa (University of Valladolid, Spain)
A partially complementary bilayer chiral metamaterial (CMM) is proposed and numerically studied. It exhibits a strong optical activity and a small circular dichroism. The retrieval results reveal that a negative refractive index is realized in a narrow band around the resonance of the chirality parameter.
All-dielectric Metasurface for Optical Focusing
Elvira Pisano (University of Sannio, Italy); Fabrizio Silvestri (Eindhoven University of Technology & Nederlandse Organisatie voor Toegepast- Natuurwetenschappelijk Onderzoek TNO, The Netherlands); Giampiero Gerini (TNO - Defence, Security and Safety, The Netherlands); Vito Lancellotti (Eindhoven University of Technology, The Netherlands); Vincenzo Galdi (University of Sannio, Italy)
In this paper we propose a design of a dielectric flat lens for visible wavelengths, capable of efficiently focus the incident field at a given distance. Our approach relies on the recently proposed exploitation of high-index dielectric resonators with spectrally overlapping electric and magnetic dipole resonances of equal strength, to design "metasurfaces" characterized by a nearly-full transmission and phase coverage of 360°. Our numerical results confirm that this technological platform, directly integrable into a nanophotonic system, is potentially capable to manipulate and efficiently focus light with low absorption losses.
Design of Metamaterial Based Wide Angle Impedance Matching Layers for Active Phased Arrays
Fabrizio Silvestri (Eindhoven University of Technology & Nederlandse Organisatie voor Toegepast- Natuurwetenschappelijk Onderzoek TNO, The Netherlands); Pierluigi Chiusolo (Universitá del Sannio, The Netherlands); Lorenzo Cifola (Thales Nederland, The Netherlands); Roland Bolt and Giampiero Gerini (TNO - Defence, Security and Safety, The Netherlands)
This paper presents the design methodology and realization of an artificially engineered anisotropic metamaterial to improve the scanning performances of active phased arrays. The optimization procedure and the design of the structures are discussed. The proposed structures show an improvement of the array performances up to 70 degrees. Different designs are presented taking into account the performance requirements and manufacture constraints.
Design Aspects of Finite Periodic Transmission Lines Based on Planar Structures
Tomas Zvolensky (Aalto University); Antti V. Räisänen, Juha Ala-Laurinaho and Constantin Simovski (Aalto University, Finland)
The focus of this manuscript is an analysis of various design aspects of composite right-left handed transmission lines (TLs) with emphasis on practical implementation to periodic structures. The design procedures used nowadays consider the influence of a period to guided wavelength ratio, coupling of parasitic fields, or fabrication inaccuracies to a limited degree. These factors become especially important for composite right/left handed (CRLH) TLs design increasing the frequency of operation. A result of this work is a thorough analysis of finite periodic transmission lines design with regard on the factors mentioned. The optimal value of the period to guided wavelength ratio was found to be 0.1–0.25 for the best trade-off between easy balancing of the unit cell and maintaining the applicability of the Bloch analysis.
Efficient Radome Optimization Through the System-by-Design Methodology
Matteo Carlin (University of Trento, Italy); Marco Salucci (ELEDIA Research Center, Italy); Lorenza Tenuti (ELEDIA Research Center, University of Trento, Italy); Paolo Rocca (University of Trento & ELEDIA Research Center, Italy); Andrea Massa (University of Trento, Italy)
An innovative approach based on the System-by-Design (SbD) paradigm is presented for radome design. The method is based on the integration of a Synthesis Block with an efficient Analysis Block based on a surrogate model for the emulation of the cost function. Some preliminary numerical results are reported in order to show the effectiveness of the proposed design methodology.
A 60GHz Passive Repeater Array with Endfire Radiation Based on Metal Groove Unit-Cells
Duo Wang (IETR, INSA de Rennes, France); Raphael Gillard and Renaud Loison (IETR & INSA, France)
A 60GHz planar reflector with endfire radiation is studied as a possible solution for passive repeaters in T-shaped corridor configurations. It uses grooves with appropriate depths in a ground plane and enjoys low cost and great convenience in fabrication. The design of the unit-cell and array for endfire radiation is discussed. A preliminary prototype is optimized.
Spectral Domain Analysis of Double Sided Open Periodic Structures
Sakineh Tooni (Technical University of Munich, Germany); Thomas F. Eibert (Technical University of Munich (TUM) & Chair of High-Frequency Engineering (HFT), Germany); Larissa Vietzorreck (Technische Universitaet Muenchen, Germany)
An analysis of open periodic stratified media is performed using external excitation of a single unit cell. The poles of the reflection and transmission coefficients are obtained from the scattering of inhomogeneous plane waves to extract the eigenmodes and corresponding eigenvalues. Surface and complex leaky modes of metamaterial structures are obtained efficiently by this method. To show the accuracy of the method the leaky and surface modes of a slab waveguide in free space are computed. Afterwards, the method is generalized to inhomogeneous periodic structures. A periodic arrangement of metallic plates is excited in its surface mode and the resulting eigenvalues and the dispersion diagram are computed. A good agreement between the results from different methods is observed.

Poster A2: Antennas Poster Session 2

Room: Gil Vicente (Hall 5)
Chairs: María García-Vigueras (IETR-INSA Rennes, France), Ozan Yurduseven (Huawei Technologies Duesseldorf GmbH, Germany)
Resonance Frequency Calculation of Spherical Microstrip Structure Using Hybrid Technique
Adam Kusiek, Rafal Lech, Piotr Kowalczyk and Wojciech Marynowski (Gdansk University of Technology, Poland)
In this paper the spherical microstrip structure is considered. The structure is composed of a metallic patch with arbitrary shape placed on a surface of dielectric material coating metallic sphere. In the analysis the hybrid technique is utilized. In this approach the finite difference technique is applied in a cavity model to determine the current basis functions on the patch. Next, using method of moments the resonance frequency of the structure is calculated. The results of proposed approach are compared with the ones obtained from commercial software and the ones published in literature.
Compact Internal Antenna (FICA) for Mobile Handset and WLAN
Reza Najafi (Tehran, Iran)
Two novels compact antenna for covering the GSM900, GSM1800, WLAN (2400MHz to 2484MHz), Bluetooth (2402MHz to 2483.5MHz) and ISM (2450MHz) bands presented that two structures-called Folded Inverted Conformal Antenna (FICA). Two proposed antenna consist of C-shaped elongated flat conductor featuring a closed slot, ground plane, shorting wall and shorting pin, and probe feed. The foam substrate applied in both antennas is chipper and better of other substrates. One antenna designed for resonate in 900MHz, 1800MHz, and other antenna has a wide impedance bandwidth measured at about 1.85GHz (2.38GHz to 4.23GHz) with low VSWR level and good radiation characteristic. The simulated values of the 1g and 10g local and averaged peak SAR on human head and hand caused by the dual band FICA mounted on handset were analysed and discussed. In both antennas good agreement is achieved between measurement and simulation.
The Design and Analysis of Pyramidal Microstrip Antenna for GPS Application
Deok Kyu Kong (ADD & Yonsei University, Korea (South)); Wan-Lai Roh (MTG, Korea (South)); Young Joong Yoon (Yonsei University, Korea (South))
In this paper, the design of a microstrip antenna array on a pyramidal surface is presented. The proposed antenna array can be used for GPS application. The antenna element is arranged on the inclined surface to reduce the mutual coupling between element antennas and to make the gain difference higher depending on a signal arrival direction. Additively, it can reduce the diameter of the array because of the inclined angle. The mutual coupling between element antennas can be reduced effectively by changing an inclined angle. The measured isolations between antenna elements were more than 30dB within the bandwidth. The gain at the boresight of the array antenna was measured to be 3.2dBi successfully within the operating frequency. And the auxiliary antenna using monopole to distribute power equally to element antennas for compensating channel unbalances are presented. Coupling balance between auxiliary antenna and element antennas was measured to be ±1.2dB
A Circularly Polarized Stacked Patch Antenna Array for Tracking Applications in S-Band
Farooq A. Tahir (National University of Sciences and Technology, Pakistan); Muhammad Saad Khan (RheinMain University of Applied Sciences, Germany)
Design of a high gain and broadband circularly polarized array antenna is presented in this paper. Basic radiating element of the proposed array consists of a driven patch and parasitic patch. Driven patch is fed through a microstrip line whereas the parasitic patch is electromagnetically coupled to the lower patch. Using this antenna element, a probefed 2x2 array antenna has been designed and tested. VSWR of the array antenna is less than 2 from 2.02 to 2.38 GHz. Axial ratio is less than 3dB from 2.15 to 2.40 GHz with peak gain of 17 dBi.
A Flexible Low Cost Fractal-Slot Multiband Antenna for Wireless Applications
Sana Ahmed and Farooq A. Tahir (National University of Sciences and Technology, Pakistan); Hammad M. Cheema (National University of Sciences and Technology (NUST), Pakistan)
A Koch fractal slot multiband antenna designed on polyimide-based flexible substrate is proposed in this paper. By cutting a Koch snowflake slot on the circular monopole, multiband characteristics are achieved. The impedance bandwidths of proposed antenna are 55.39 % for first band (0.77 - 1.36 GHz), 29.50 % for second band (1.85 - 2.49 GHz) and 35.3 % for third band (2.80 – 4.00 GHz) with the gain of 1.25 dBi, 1.54 dBi and 2.23 dBi respectively. The size of antenna is 115 x 90 mm2. The proposed flexible antenna is suitable for flexible mobile devices for omnidirectional coverage of GSM 850, GSM 900, PCS 1990, UMTS, 2.4 GHz WLAN, ISM & Bluetooth, LTE 2300 and WiMAX bands.
Antenna Arrays for Unmanned Aerial Vehicle
Diana Navarro-Méndez (Universidad Politécnica de Valencia & Escuela Politécnica Nacional, Spain); Hon Ching Moy-Li (Universidad Politécnica de Valencia, Spain); Fernando Carrera-Suárez (Universidad Politécnica de Valencia & Escuela Politécnica Nacional, Spain); Miguel Ferrando-Bataller (Universitat Politècnica de València, Spain); Mariano Baquero-Escudero (Universidad Politécnica de Valencia, Spain)
This paper presents two antenna solutions for an Unmanned Aerial Vehicle (UAV), where the available space for the antenna in the UAV has a cylindrical form. The antennas will operate at 2.45GHz in the Wi-Fi frequency band. The designed antennas are composed by a circular array of four elements conformed to cylindrical shape. A rectangular microstrip patch antenna and a PIFA antenna have been selected as basic the radiating elements of each array. Simulation results show a good matching level at the operating frequency and radiation patterns with a quite omnidirectional behavior for both antenna arrays.
An Analysis of Elliptical-Rectangular Patch Structure on Multilayer Non-Confocal Elliptic Cylinders
Rafal Lech and Adam Kusiek (Gdansk University of Technology, Poland)
The resonance frequency problem of an elliptical-rectangular patch mounted on multilayered dielectric coated elliptic conducting cylinder, is investigated in this paper. A full-wave analysis and a moment-method calculation are employed. The analysis is carried out considering the expansion of the field as a series of Mathieu functions. An additional theorem for Mathieu functions is utilized to investigate the non-confocal ellipse case. The complex resonance frequencies for the structures with double layer substrate and structure with superstrate layer are calculated.
Simulation-Driven Size Reduction of Antenna Structures Using Adjoint Sensitivities and Trust Regions
Adrian Bekasiewicz and Slawomir Koziel (Gdansk University of Technology, Poland); J. Pieter Jacobs (University of Pretoria, South Africa)
Explicit size reduction of antenna structures using cost efficient EM-simulation-driven optimization is discussed. The proposed approach directly handles the antenna size (as the main design objective) while ensuring satisfaction of electrical performance parameters by means of suitably defined penalty functions. For the sake of computational efficiency, optimization is carried out using cheap adjoint sensitivities and trust region framework utilized as convergence safeguard. Our technique is illustrated through a design of a compact quasi-isotropic dielectric resonator antenna.
Self-Aligned Microstrip-fed Spherical Dielectric Resonator Antenna
Daniel López Cuenca (University of Stuttgart &amp; IHF -- Institute of Radio Frequency Technology); Jan Hesselbarth (University of Stuttgart & IHF -- Institute of Radio Frequency Technology, Germany)
A new concept for a microstrip-fed spherical dielectric resonator antenna is presented. A microstrip resonating structure on thin substrate is used to feed a spherical dielectric resonator. Precise alignment of the spherical dielectric resonator with respect to the microstrip feed is ensured by a shallow hole in the microstrip substrate placed close to the feed structure. Use of a higher-order resonance mode of the dielectric sphere eases excitation and increases directivity of radiation. Simulations and measurements of prototypes operating at 6 GHz are disclosed.
Miniaturized DRA Array for GNSS Applications
Stefano Caizzone and Achim Dreher (German Aerospace Center (DLR), Germany)
The increase in GNSS satellites and services is fostering a new wave of applications related to satellite navigation. Such increase is also followed by more and more threats, aiming at signal disruption. In order to fully exploit the potentialities, being able at the same time to counteract threats such as interference and jamming, smart antenna systems are being developed worldwide, with the requirements of multi-band operation and compactness. In order to answer such need, the present work proposes a miniaturized 2x2 array able to operate at E5, L2, E6 bands, with an overall footprint of only 3.5" (89 mm), by means of dielectric resonator antenna (DRA) technology
High Profile Rectangular Dielectric Resonator Antenna Sequentially-fed for Improved Quality Dual Circular Polarization
Baptiste Hornecker (EPFL - LEMA & Dassault Aviation, Switzerland); Juan R Mosig (Ecole Polytechnique Federale de Lausanne, Switzerland)
This paper presents a new excitation scheme producing dual circular polarisation in a class of Dielectric Resonator Antennas characterized by their high profile. The excitation uses a sequential feeding, which produces high quality dual circular polarization over a wide range of angles and results in a polarisation bandwidth of 20% to 30% in the Ku-Band. A similar impedance bandwidth can be achieved. The excitation fabrication involves only standard PCB methods and the resulting antenna element is robust, compact and well adapted to array integration.
A 60-GHz Coplanar-Waveguide-Fed Slot-Coupled Rectangular DRA Design Using the Theory of Characteristic Modes
Tomás Bernabeu-Jiménez (Universitat Politècnica de València & Instituto de Telecomunicaciones y Aplicaciones Multimedia (ITEAM), Spain); Alejandro Valero-Nogueira and Felipe Vico (Universidad Politécnica de Valencia, Spain); Antonio Vila-Jiménez and Daniel Sánchez-Escuderos (Universitat Politècnica de València, Spain); Francois Gallée (Télécom Bretagne, France)
A novel method to design a coplanar-waveguide-fed slot-coupled rectangular dielectric resonator antenna is presented in this paper. A new concept of characteristic modes to design a slot-coupled rectangular dielectric resonator antenna is applied here for the first time. This study permits to optimize the radiation bandwidth in the same analysis process for both the dielectric and the slot. The complete antenna is designed for low-temperature co-fired ceramic fabrication. The goals are to fabricate all the antenna for low permittivity in the same process, to match the dielectric resonator to the coplanar-waveguide-fed line for the frequency range of ISM at 60-GHz. The obtained results show that the proposed antenna radiation bandwidth determined by -10dB return loss can be as large as 14-GHz more than 23%, centered at about 60-GHz.
An Improved Simulation Method of Multipactor in High Power Antennas
Yun Li (China Academy of Space Technology Xi an, China)
An improved method for multipactor simulation in antennas has been proposed. Based on the Particle-In-Cell technology and the Finite-Difference Time-Domain method, the interaction between fields and electrons is properly modeled. A newly established boundary has been proposed for the absorbing of particles. Thus, the diffusion of the particles in the radiation space has been cut off and the simulation efficiency improved. In addition to the classic secondary electron emission model, the measured practical secondary electron yield is used, which increases the accuracy of the algorithm.Simulation results of a helix antenna show that the generation of multipactor can be visualized. It is demonstrated that the main mechanism that rules multipactor in the helix antenna is the single surface impacting and emission.Furthermore, the discharge threshold of the radiation element is estimated from the temporal evolution of the particles, which make this method promising in high-power space applications.
Extended Low-Profile Planar Lens Antenna with Multilayer Metallic-Hole Array
Daniel Sánchez-Escuderos (Universitat Politècnica de València, Spain); Marta Cabedo-Fabrés (Universidad Politécnica de Valencia, Spain); Eva Antonino-Daviu and Miguel Ferrando-Bataller (Universitat Politècnica de València, Spain)
This paper presents a low-profile antenna based on the use of a multilevel metallic hole array (MHA). The antenna is fed by an open rectangular waveguide placed at a short distance from the MHA. The array operates as a frequency selective surface (FSS) to enhance the directivity of the rectangular aperture within the frequency band of operation of the FSS. The small distance between layers gives the MHA a low-profile shape. In addition, the fabrication of the MHA is straightforward, what facilitates the implementation at any frequency band. A symmetric design with two circles of holes surrounding a central element is presented. The frequency band of operation of the proposed antenna is 19.7-21.2 GHz. Results show an increment of 8 dBi in the maximum directivity with respect to the isolated rectangular aperture.
Implementation of Optically Transformed Devices with a Bed of Nails
Oscar Quevedo-Teruel (KTH Royal Institute of Technology, Sweden); Rhiannon C Mitchell-Thomas (University of Exeter, United Kingdom (Great Britain)); Jose-Luis Vazquez-Roy, Luis Inclan-Sanchez and Eva Rajo-Iglesias (University Carlos III of Madrid, Spain)
Transformation optics has recently brought new design opportunities for antennas, with a special emphasis on lenses [1]. The named non-Euclidean transformations [2] permits the combination of graded-index structures and sculpted surfaces to eliminate singularities in conventional lenses [3]. Here, we demonstrate how these structures can be implemented by the use of bed of nails surfaces.
Nonlinear Optical Gap Antenna, an Optoelectronic Interface At the Nanoscale
Marie-Maxime Mennemanteuil (Laboratoire Interdisciplinaire Carnot de Bourgogne); Mickaël Buret (Laboratoire Interdisciplinaire Carnot de Bourgogne, France); Alexandre Bouhelier (University of Burgundy, France)
We introduce strongly coupled optical gap antennas to interface optical radiation with current-carrying electrons at the nanoscale. The transducer relies on the nonlinear optical and electrical properties of an optical gap antenna operating in the tunneling regime. We discuss the underlying physical mechanisms controlling the conversion and demonstrate that a simple two wire optical antenna can provide advanced functionalities in an optoelectronic information processing platform.
Harvesting Thermal Infrared Emission Using Nanodipole Terminated by Traveling Wave Rectifier
Islam Hashem Sayed (North Carolina State University, USA); Nadia Rafat (Cairo University, Egypt); Ezzeldin Soliman (The American University in Cairo, Egypt)
A rectenna formed from nano-dipole antenna terminated by plasmonic metal-insulator-metal travelling wave transmission line rectifier is introduced. The proposed rectenna is suitable for thermal energy harvesting at 30 THz. The vertical spacing between the two metal layers is kept at 2 nm in order to maximize the rectifier's responsivity. Such small spacing can be realized using Atomic Layer Deposition (ALD) technique. If compared with rectennas with localized rectifiers, the proposed rectenna has an enhanced system efficiency due to the efficient matching between the nantenna and rectifier.
Wideband Printed Tapering Quadrifilar Helical Antenna for GNSS
Juan Lei and Guang Fu (Xidian University, China); Yang Hao (Queen Mary University, United Kingdom (Great Britain))
A wideband conical printed tapering quadrifilar helical antenna for Global Navigation Satellite System (GNSS) is presented. By wrapping four printed tapering helical strips on the surface of modified hollow conical dielectric rod and using wideband network with stable amplitude and phase distribution to feed, the proposed antenna are effectively designed to achieve wide bandwidth, desired gain and wide angle axial ratio characteristics, which are mainly required for GNSS receiver, especially for measured receiver with high precision.
Wideband Crossover Structure with Double Ring Resonators
Rafal Lech, Wojciech Marynowski and Adam Kusiek (Gdansk University of Technology, Poland); Jerzy Mazur (Gdansk University of Technology,)
The structure of a four-port microstrip crossover is presented. The device is composed of two ring resonators, one circular and one built from meander lines, connected by four straight lines. The equivalent circuit model of the crossover is derived. The structure is designed on thin and flexible substrate to allow it to bend. The possibility of applying the device on curved surfaces is tested experimentally.
Integrated Filtering-Antenna with Controllable Frequency Bandwidth
Chun-Xu Mao (University of Surrey, United Kingdom (Great Britain)); Steven Gao and Zhengpeng Wang (University of Kent, United Kingdom (Great Britain)); Yi Wang (University of Birmingham, United Kingdom (Great Britain)); Fan Qin (School of Electronics and Information, Northwestern Polytechnical University, China); Benito Sanz-Izquierdo (University of Kent, United Kingdom (Great Britain)); Qing-Xin Chu (South China University of Technology, China)
An integrated design of a band-pass filter and a patch antenna is proposed in this paper by using an aperture coupled structure. Traditionally, the microwave filter and antenna are designed separately using 50 Ohm interface and then connected by transmission lines, which lead to a large size and more loss. Here, the antenna and microwave filter are directly integrated without a 50 Ohm interface between them. Compared with the traditional cascade designing, the co-design of filter and antenna has a more compact size, simpler configuration, improved frequency selectivity and higher system efficiency. The frequency bandwidth also can be controlled by adjusting the dimension of the coupling aperture in the ground. The measured results agree very well with the simulations, showing the filtering-antenna has good performance in impedance matching, radiation pattern and antenna gain.
Optimum Design of a Miniaturized Onchip Wide Band Power Divider-Combiner Combined with Impedance Transformer
Alireza Shamsafar (University of Calabria, Italy); Elnaz Abaei (Universita Della Calabria, Italy); Hugo Oswaldo Moreno Aviles (Escuela Superior Politecnica de Chimborazo & Universita della Calabria, Ecuador)
In this paper a design procedure for Monolithic Microwave Integrated Circuit (MMIC) power divider based on lumped components is proposed. Its circuit model is used to present a design procedure based on the Method of Least Squares (MLS) which has been developed to include the appropriate dispersion models and the dissipation effects. The conversions among the impedance and scattering matrices based on circuit analysis are used to find expressions for outputs, reflection and transmission coefficients (as scattering parameters) for the construction of an error function whose minimization is performed by the combination of genetic algorithm and conjugate gradient method (to benefit from their advantages and avoid their shortcoming)which gives the value of each component of the optimum design of the on chip power divider. The proposed design method has been applied to design two examples of the lumped component power divider, one of which has been fabricated on SiGe BiCMOS.
Integrated Suspended Stripline Structure (SSS) with J-shape Defected Stripline Structure (DSS) to Remove Undesired Signals in Wideband Applications
Zahriladha Zakaria (Universiti Teknikal Malaysia Melaka, Malaysia); Mohamad Ariffin Mutalib (Universiti Teknikal Malaysia Melaka & Hang Tuah Jaya, Malaysia); Sam Weng Yik (UTEM, Malaysia)
This paper presents a novel design of integrated bandpass filter (BPF) based on Suspended Stripline Structure (SSS) with Defected Stripline Structure (DSS) to produce bandpass and band reject characteristics. The bandpass filter produces a wideband frequency from 3.1 GHz to 6 GHz with a return loss, S11 better than -15 dB and insertion loss, S21 of around 0.1 dB. While, the DSS exhibits a band reject response, better than -30 dB at a frequency of 5.2 GHz with a narrow bandwidth. Thus, the integrated BPF and DSS will produce wideband bandpass and band reject response simultaneously in the same structure. The design is simulated on a Roger Duroid RO4350 with a dielectric constant, εr of 3.48 and a thickness of 0.508 mm. This new class of generalized Chebyshev bandpass filter with DSS is useful to remove any undesired signals in wideband communication system particularly in civilian and military radar applications.
Analytical Treatment of Microstrip Monopole Antenna with Finite Ground Plane
Anushruti Jaiswal (CARE, IIT Delhi, India); Mahesh P Abegaonkar (IIT Delhi, India); Shiban K Koul (Indian Institute of Technology Delhi, India); Srinivasa Rao Zinka (DAIICT, Gandhinagar, India)
The effect of finite ground plane on resonant frequency of microstrip monopole antenna is studied. Electric field corresponding to a microstrip monopole antenna follows an elliptic path between the monopole and the finite ground plane, and is analogous to TEc01 mode of an elliptic waveguide with PMC walls. The authors have used this elliptic waveguide model to understand the effect of size of the finite ground plane on resonant frequency. A prototype of microstrip monopole antenna resonating at 2.03 GHz on a substrate having er = 4.3 is fabricated. Good agreement between the theoretical and the measured results showed the validity of the proposed cavity model and the related analysis.
Characteristic Basis Function Patterns Method for Reflector Antenna Calibration: An Extension to Multiple Frequencies
Ngoy Mutonkole (University of Stellenbosch, South Africa); Dirk de Villiers (Stellenbosch University, South Africa)
A simple and effective method to extend the characteristic basis function pattern (CBFP) method to multiple frequencies is presented herein. Transformation matrices are generated from simulated basis functions at each frequency of interest. By computing model coefficients, using a few directional measurements of any given pattern at a single frequency, linear algebra is applied to extract expansion coefficients at any other frequency within the model's range by utilising the transformation matrix. The full radiation pattern at all frequencies is then recovered from a single frequency measurement using the extracted expansion coefficients.
Geometrical Synthesis of Offset Reflector Antennas Using Local Axis-Displaced Quadric Surfaces
Rafael Abrantes Penchel (São Paulo State University (UNESP), Brazil); Jose R Bergmann (PUC-Rio, Brazil); Fernando Moreira (Federal University of Minas Gerais, Brazil)
This work investigates an alternative numerical procedure for the geometrical synthesis of offset reflector antennas with an arbitrary radiation pattern in the far-field region according to geometrical optics. The method uses local axis-displaced quadric surfaces to describe the shaped reflector. In this approach, a nonlinear operator must be solved as a boundary value problem. To illustrate the method, we have chosen an offset configuration with a circular contour coverage and Gaussian power density. The results were validated by the physical optics approximation.
Equivalent Circuit of a Quadraxial Feed for Ultra-Wide Bandwidth Quadruple-Ridged Flared Horn Antennas
Theunis S Beukman (Dassault Systèmes Deutschland GmbH, Germany); Petrie Meyer (Stellenbosch University, South Africa); Rob Maaskant (CHALMERS, Sweden); Marianna Ivashina (Chalmers University of Technology, Sweden)
An equivalent circuit model of a quadraxial feed for a 6:1 bandwidth quadruple-ridged flared horn (QRFH) antenna is presented. The circuit is synthesised by only 3 unknowns and achieves high accuracy for a wide range of dimensions. This model allows fast synthesis of optimal feeding designs which are applicable for QRFHs.
An All-Metal K-Band Reflector Antenna for a Mechanically Steerable Data Downlink System
Joakim F Johansson, Mattias Viberg and Johan Petersson (RUAG Space AB, Sweden); Per Magnusson (Ruag Space Sweden, Sweden)
An all-metal K-band reflector antenna for use in space-based mechanically steerable data downlink systems has been designed. The antenna comprises a deep dish with a splash-plate type feed. The design provides a compact low-mass antenna for space use.
Transparent Microwave Crossover for Transparent Butler Matrix Using Micro-metal Mesh Conductive Film
Bashir Muhammad Saad (Universiti Teknologi Malaysia & Faculty of Electrical Engineering, Malaysia); Sharul Kamal A. Rahim and Thomas Peter (Universiti Teknologi Malaysia, Malaysia); Mohammad Abediankasgari (University of Surrey, United Kingdom (Great Britain)); Shadi Danesh ((WCC) UniversitiTeknologi Malaysia, UTM, Malaysia)
This paper presents the design of a novel transparent microwave crossover (MC) for transparent Butler matrix (BM) using a proprietary self-assembling nano-particle technology based Micro-metal Mesh (MM) conductive film. The transparent MM conductive film has a sheet resistance of 0.7 ohms/sq and a visible-light transmission of 75 %, resulting in high transparency and good conductivity, respectively. The proposed transparent crossover is placed on a 2 mm-thick glass substrate of dielectric 5.7 and designed to operate at 2.45 GHz. A layer of MM film placed at the back of the glass serves as a ground. The transparent MC delivered measured crossing coupling of 1.5 dB. The transparent MC can be used as a building block for realizing a transparent Butler Matrix (BM) Beam Forming Network (BFN) for inter/intra-vehicle wireless communication (IIVWC) in Intelligent Transport System (ITS). Besides being transparent, the proposed MC has a 0.25 mm profile excluding the glass substrate.
An Investigation of Offset-Fed Beams on the Proposed SKA Dishes with Various Degrees of Shaping
Robert Lehmensiek (EMSS Antennas, South Africa); Isak Theron (EMSS Antennas (Pty) Ltd, South Africa); Dirk de Villiers (Stellenbosch University, South Africa)
A limited set of possible optics candidates for the Square Kilometre Array (SKA) was recently proposed. This paper investigates the electromagnetic performance of centre-fed and offset-fed feeds on a subset of these classical conic section dual reflector systems and also on shaped versions of these reflectors with various degrees of shaping.
Phyllotactic Arrangements of Reflector Mesh Facets to Decrease Grating Lobes
Jean-Christophe Angevain (ESA, The Netherlands); Gonçalo Rodrigues (European Space Agency, The Netherlands); Julian Santiago-Prowald (European Space Agency (ESTEC), The Netherlands); Cyril Mangenot (Api-Space, France); Leri Datashvili (LLB-TUM, Germany)
For manufacturing reasons, reflector antennas using mesh exhibit multiple quasi-flat facets arranged with a regular lattice on the Radio-frequency reflective surface. Under certain conditions, this is prone to generate high level sidelobes, called faceting lobes. This paper investigates some deterministic ways to reduce the faceting sidelobes of mesh reflector antenna by applying phyllotactic arrangements to the supporting net of the mesh reflector surface. This nature-inspired arrangement is derived from a spiral pattern with a Fibonacci sequence and is known to be irregular.
Focal Plane Array Size Reduction for Terahertz Transceivers in Integrated Technology
Erio Gandini (ESA - European Space Agency, The Netherlands); Nuria LLombart and Andrea Neto (Delft University of Technology, The Netherlands)
Focal plane arrays in integrated technology represent a promising solution to improve the image acquisition speed of imaging system at submillimeter frequencies for security applications. The aim of this work is the size reduction of these arrays while maintaining a large field of view. A standard fly's eye solution is compared to two novel solutions indicated here as virtual focal plane array and aperture plane array. In both cases, a single lens is fed by several antennas constituting the array. This allows a more efficient wafer usage. Moreover, for comparable size of the focal plane array, both virtual focal plane array and aperture plane array show larger field of view than the fly's eye architecture.
Axially Slotted Antenna on Elliptic Cylinder Coated with Biaxial Anisotropic Material
Abdul-Kadir Hamid (University of Sharjah, United Arab Emirates)
Radiation properties of an axially slotted circular or elliptical antenna coated with biaxial anisotropic material are investigated. The fields inside and outside the dielectric layer are expressed in terms of appropriate Mathieu functions with unknown coefficients. The boundary conditions at various surfaces are applied to obtain the unknown field expansion coefficients. Numerical results are presented graphically for the radiation pattern, aperture conductance and antenna gain.
Generation of a Cosecant-Squared Radiation Pattern with a Superstrate-Like Leaky-Wave Antenna
Francesco Scattone (Microwave Vision Group (MVG), Italy); Mauro Ettorre (University of Rennes 1 & UMR CNRS 6164, France); Ronan Sauleau (University of Rennes 1, France); Nelson Fonseca (European Space Agency, The Netherlands)
In this paper a planar leaky-wave antenna in a superstrate-like configuration is used to generate a cosecant-squared radiation pattern. As a difference with previous designs based on such configurations, the superstrate here is truncated. In this way an asymmetric illumination of the radiating aperture is achieved, thereby generating the required pattern. The antenna is fed by a waveguide aperture etched in the ground plane of the structure. A dispersion analysis is adopted for designing the antenna. Full-wave numerical results validate the proposed approach and structure. The proposed antenna may find application in mobile communication and radar systems.
Scalar Metasurface Antennas with Tilted Beam
Maciej Smierzchalski (CEA, France); Massimiliano Casaletti (Sorbonne Universités UPMC, France); Mauro Ettorre (University of Rennes 1 & UMR CNRS 6164, France); Ronan Sauleau (University of Rennes 1, France); Nicolas Capet (ANYWAVES FRANCE, France)
The paper deals with the design of scalar metasurface antennas pointing to a predefined tilted direction. The equivalent electric current over the metasurface is used to derive design equations for the generation of a desired far field pattern based on the scalar impedance condition associated to the metasurface. In particular, it is shown that scalar metasurfaces can be used to generate linear and circular polarizations for a fixed pointing direction by properly changing locally the scalar impedance boundary condition. Two solutions are presented at 20 GHz, one for each polarization. Full-wave results validate the proposed approach.
Dual Band Isoflux Ultraflat Meta Antennas
Amagoia Tellechea (Public University of Navarra, Spain); Enrica Martini (University of Siena, Italy); David González-Ovejero (Centre National de la Recherche Scientifique - CNRS, France); Marco Faenzi (University of Siena, Italy); Gabriele Minatti (Wave Up S. r. l., Italy); Stefano Maci (University of Siena, Italy)
This paper presents preliminary results of a study that aims at designing a dual band modulated metasurface antenna radiating an isoflux shaped beam suitable for earth observation missions.
Low-Profile Dual-band Circularly Polarized Microstrip Antenna for GNSS Applications
Faycel Fezai (University of Limoges-XLIM - UMR CNRS N°7252, France); Amro A. Nour (American University of Kuwait, Kuwait); Thierry Monediere (XLIM-UMR 6172-CNRS, University of Limoges, France); François Torres (University of Limoges-XLIM - UMR CNRS N°7252, France); Regis Chantalat (Center Technology Transfer CISTEME, France)
This article presents a design of a micro-strip circularly polarized antenna intended for the Global Navigation Satellite Systems (GNSS). The presented device is composed of a micro-strip slotted patch antenna printed on a Rogers RO3006 substrate, a foam layer of 2 mm thick and a wideband commercial 3-dB SMT coupler. The combined fullwave antenna results with the measured S-Parameters of the coupler shows very good performances in terms of antenna matching and axial ratio on larger bandwidths
A Single Ka-Band Antenna Aperture for TX and RX Operation Applying a Dual-Layer Partially Reflective Surface
Alexander Krauss, Hendrik Bayer and Ralf Stephan (Technische Universität Ilmenau, Germany); Matthias Hein (Ilmenau University of Technology, Germany)
This publication presents a leaky-wave antenna panel comprised of a dual-layer partially reflective surface (PRS) intended for transmit and receive operation in Ka-band. Several of these panels are installed on the outdoor-unit of a low-profile user-terminal intended for satellite communication on the move during emergency scenarios. Due to widely separated up- and downlink-frequencies in Ka-band the antenna panel provides a dual-band behaviour and offers circular polarisation. This paper presents the design of the antenna in detail and discusses simulation and measurement results.
Role of Symmetries in Periodic Leaky-Wave Antennas, with Emphasis on the Double-Asymmetry Case
Amar Al-Bassam (RWTH Aachen University, Germany); Simon Otto (IMST, Germany); Christophe Caloz (Ecole Polytechnique de Montreal, Canada)
Symmetries play a major role in the properties of periodic leaky-wave antennas (LWAs). it was shown that symmetric LWAs have limitations when operating at the broadside frequency and that the key point to mitigate these limitations is to introduce asymmetry into the unit cell of the antenna structure, i.e. transversal or longitudinal asymmetries. This paper exploits a third type of asymmetry that combines the transversal and longitudinal asymmetries to further enhance the performance of LWAs.
Dual-polarized One-Dimensional Leaky Wave Antenna
María García-Vigueras (IETR-INSA Rennes, France); Marc Esquius Morote (Ecole Polytechnique Fédérale de Lausanne, Switzerland); Juan R Mosig (Ecole Polytechnique Federale de Lausanne, Switzerland)
In this abstract we present a one-dimensional leaky-wave antenna fed from two ports that provides a dual-polarized radiation pattern. It is the first time that dual-polarized radiation is achieved from a single one-dimensional leaky-wave radiating aperture. This simple and robust antenna provides high gain in both horizontal and vertical linear polarization with low cross-polarization levels (below -40dB) which makes it potentially suitable for applications such as polarimetric radars.
Low-Profile High-Gain Tilted-Beam Fabry-Perot Antenna
Fan Qin (School of Electronics and Information, Northwestern Polytechnical University, China); Steven Gao (University of Kent, United Kingdom (Great Britain)); Chun-Xu Mao (University of Surrey, United Kingdom (Great Britain)); Gao Wei, Jiadong Xu and Jianzhou Li (Northwestern Polytechnical University, China)
A low-profile high-gain Fabry-Perot (FP) antenna with tilted-beams is proposed in this paper. A novel partially reflective surface (PRS), consisting of square patches and mesh grids etched on both sides of dielectric substrate, is designed to operate at 10 GHz. In the proposed design, the sizes of square patches and mesh grids can be adjusted separately, which provides two methods to achieve the tilted-beam: one is to vary the sizes of square patches to change the E-field phase distribution on the surface of PRS, and the other is to change the dimensions of mesh grids to obtain beam tilted characteristics. Simulation results show that it can obtain a gain of 13.7 dBi for a 23 degree beam tilting using the first method and a gain of 13.4 dBi for a 27 degree beam tilting by varying the mesh grids, respectively.
Periodic and Periodic Phase-Reversal Leaky Wave Antennas in Reduced Permittivity Substrate Integrated Waveguide
Robert Henry (University of Calgary, Canada); Michal Okoniewski (University of Calgary & Acceleware Ltd, Canada)
Recently proposed half-mode substrate integrated waveguide periodic and periodic phase-reversal leaky wave antennas (LWAs) are investigated using a reduced substrate permittivity. Both antennas offer broadside scanning radiation. The periodic phase-reversal LWA is able to maintain full space scanning while the periodic LWA suffers from grating lobes due to the larger radiating element spacing.
Smart Notch Detection Techniques for Robust Frequency Coded Chipless RFID Systems
Ahmed El-Awamry (University of Duisburg-Essen, Germany); Abdelfattah Fawky (University of Duisburg Essen, Germany); Mohamed El Hadidy (FOM University of Applied Science & CST-Middle East, Germany); Thomas Kaiser (Universität Duisburg-Essen, Germany)
The main objective of this work is to introduce two adaptive window-based notch detection techniques for UWB Frequency Coded chipless RFID system. The first proposed algorithm is the Window Based Singular Value Decomposition (WBSVD), where various frequency dependent patterns of the notch are used as a training sequence for pre-defined bandwidth (window) to create an orthonormal basis functions. The WBSVD accurately and rapidly detects the notch based on the minimum distant vector criteria. In the second algorithm, Adaptive Energy Detection, an adaptive threshold is estimated for each window depending on the Probability of false alarm considering the frequency selective channel. Simulation results show that both algorithms are immune to environmental effects such as cluttering, fading and multipath components. Moreover, the two algorithms operated efficiently regardless on the type of chipless tags. A comprehensive comparison and the trade-offs between the two techniques would be illustrated at the end.
Printable Depolarizing Chipless RFID Tag Based on DGS Resonators for Suppressing the Clutter Effects
Maher Khaliel (Universität Duisburg-Essen, Germany); Mohamed El Hadidy (FOM University of Applied Science & CST-Middle East, Germany); Thomas Kaiser (Universität Duisburg-Essen, Germany)
In this paper, a novel Frequency Coded depolarizing chipless RFID tag is introduced. The uniplanar printable, symmetrical and easily coded tag consists of L-shape Defected Ground Structure (DGS) resonators defining the tag signature and two orthogonally polarized UWB monopole antennas for realizing the cross-polarization retransmission process. The number of notches could be easily increased by adding parallel resonators preserving the same tag size. The polarization diversity is utilized to reduce the mutual coupling, suppress the channel clutter effects and efficiently detecting the tag on metallic platforms. An 8-bits code tag prototype from 3.1 GHz to 6.1 GHz is presented and the maximum readable number of notches will be investigated. The UWB monopole antenna and the DGS resonators simulation, implementation and measurement are separately demonstrated. The manufactured chipless RFID tag operation is verified in indoor real-world environment and will be illustrated in the full paper.
A Printed Planar Helix Antenna
Aneesh Kommalapati (Nanyang Technological University, Singapore); Chen Zhao (Nanjing University of Information Science and Technology, China); Sheel Aditya (Singapore)
This paper presents design, fabrication and measurement results of a novel broadband, circularly polarized, planar helix antenna operating at X-band that is fabricated using printed circuit techniques. The conventional circular helix antenna is modified into a planar helix antenna, and the effect of various parameters like pitch angle, dimensions, feed and substrate, etc. on the impedance and radiation characteristics is studied. The performance parameters under investigation are S11, directivity, side lobe level, and axial ratio. These parameters are obtained using CST Microwave Studio. For a design with 5 turns of the planar helix, the results of the simulations are as follows: over a frequency range of 8.3-11.7 GHz, S11 is less than -10 dB, directivity ranges from 11.7-12.6 dBi, and the axial ratio ranges from 0.68-3.3 dB. The corresponding design is fabricated using RO4003C dielectric substrates. The measurement results match the simulation results reasonably well.
Suspended-strip Gap Waveguide Coupled-Line Properties for Ka-band Component Design
Antonio Berenguer (Universitat Politecnica de Valencia & Instituto de Telecomunicaciones y Aplicaciones Multimedia, Spain); Mariano Baquero-Escudero (Universidad Politécnica de Valencia, Spain); Daniel Sánchez-Escuderos and Felipe Vico (Universitat Politècnica de València, Spain)
Gap waveguides have been shown in the last years as a possible waveguiding solution in mm-wave band. These waveguides do not require neither metal contact nor dielectrics. In particular, quasi-TEM transmission lines avoiding the high dielectric losses of materials at mm-wave frequencies can be designed with such structures. An interesting case is the Suspended-Strip Gap Waveguide (SSGW) which allows a fixed design of the pin lattice with possible re-utilization. Nevertheless, characterization of this transmission line is still far from the well-known design expressions and charts available for classical transmission lines. This work addresses this problem, presenting a study of the SSGW impedance in the Ka-band which includes odd and even impedances of SSGW coupled lines. Final paper will include the design of a component based on coupled-lines.
Characteristic Mode Based Pattern Reconfigurable Antenna for Mobile Handset
Hui Li (Dalian University of Technology, China); Rui Ma and John Chountalas (Lund University, Czech Republic); Buon Kiong Lau (Lund University, Sweden)
In this work, a dual-band (824-894 MHz and 2110-2155 MHz) handset antenna with pattern reconfigurability at both bands is designed by loading the periphery of the chassis with a metal bezel. The bezel loading adds a new resonant characteristic mode to the chassis, on top of the fundamental resonant mode. These two modes are selectively excited for pattern reconfigurability using a suitable feed and two PIN diodes, which yield an envelope correlation of below 0.3 in the low band (0.08 at 860 MHz) and around 0.1 in the high band. Moreover, since the proposed antenna is fully integrated into the bezel structure, it does not occupy any extra space on the chassis, which also allows more antennas to be implemented, e.g., for MIMO applications.

Poster P1: Propagation Poster Session 1

Room: Fernão M Pinto (Hall 4)
Chairs: Corentin Friedrich (IRCCyN - Ecole Centrale de Nantes, France), Flávio M. da Silva Jorge (European Space Agency, The Netherlands)
Faster Resolution of the 3-D Forward Problems in Microwave Imaging by a Partial-Block BiCGStab Algorithm
Corentin Friedrich (IRCCyN - Ecole Centrale de Nantes, France); Sébastien Bourguignon (Ecole Centrale de Nantes, IRCCyN, France); Jérôme Idier (LS2N, France); Yves Goussard (Ecole Polytechnique de Montréal, Canada)
In microwave image reconstruction, the biconjugate gradient stabilized (BiCGStab) algorithm is generally used to solve the 3-D forward problem. In practice, the number of forward problems that must be solved simultaneously is equal to the number of available illuminations. Here, we propose the use of a block version of the BiCGStab algorithm that can take advantage of the fact that all forward problems share the same linear operator, thereby significantly reducing the amount of computation. In order to make the technique faster and more robust, an implementation based on a partition of the incident fields is introduced. Simulations are carried out on a realistic setup for image reconstruction and reveal the superiority of the proposed algorithm over the BiCGStab method, mainly for high contrasted objects.
Multiple Signal Classification (MUSIC) Method Approach to the Intensity-Only Inverse Reconstruction Based on the Microscopy System
Rui Chen and Xudong Chen (National University of Singapore, Singapore)
This paper investigates multiple signal classification(MUSIC) imaging method approach to solve the inverse scattering problem based on microscopy system using intensity-only data. The location of a collection of small scatterers embedded in the focal region can be determined. Due to the specific characteristic of the microscopy system, the relationship between the rank of the multistatic matrix and the number of the small scatterers is different from that in traditional inverse scattering. Multiple scattering between scatterers is considered. Numerical simulations show that the inverse construction using MUSIC method dramatically improves the resolution of microscopy systems.
Stored Grain Spoilage Monitoring Via 3D Microwave Imaging
Mohammad Asefi and Joe LoVetri (University of Manitoba, Canada); Ian Jeffrey (151 Research Inc, Canada); Majid Ostadrahimi (University of Manitoba Winnipeg, Manitoba, Canada); Amer Zakaria (American University of Sharjah, United Arab Emirates); Colin Gilmore (University of Manitoba & 151 Research Inc, Canada); Paul Card (151 Research Inc., Canada)
Preliminary results on using microwave imaging for early detection of spoilage and the monitoring of stored grain are presented. A full vectorial 3D microwave imaging system to detect grain spoilage inside a silo is being developed. The generic configuration of this system is described, and results based on synthetically generated data are presented.
A Forward Approach to Establish Parametric Scattering Center Models for Complex Targets
Yang He (School of Electronic Information, Wuhan University, China); Guo-Qiang Zhu (Wuhan University, China); Si-yuan He and Yun-hua Zhang (School of Electronic Information, Wuhan University, China)
We present a forward approach to establish parametric scattering center models for complex targets. In this approach, an automatic technique based on ray tracing and clustering is first developed to extract scattering centers directly from the computer-aided design (CAD) model of the targets. Following this, a set of forward methods is developed to determine the physically relevant parameters of two-dimension (2-D) attributed scatterers. Finally, this approach is validated through the parametric model establishment of a tank target and good agreement has been demonstrated between the reconstructed and actual radar characteristics. The proposed approach provides a forward way of constructing radar targets' feature database based on 2-D parametric scattering center model.
Physical-information Exploitation in Inverse Scattering Approaches for GPR Survey
Lorenza Tenuti (ELEDIA Research Center, University of Trento, Italy); Marco Salucci (ELEDIA Research Center, Italy); Lorenzo Poli (ELEDIA Research Center, University of Trento, Italy); Giacomo Oliveri (University of Trento & ELEDIA Research Center, Italy); Andrea Massa (University of Trento, Italy)
An imaging technique is proposed for the retrieval of sparse dielectric targets buried in a lossy half-space. To achieve this goal, the contrast source formulation of the inverse problem is solved through a customized implementation of the multi-task (MT) Bayesian Compressive Sensing. Some preliminary results are shown in the in order to demonstrate the effectiveness of the proposed approach when solving time- harmonic subsurface prospecting problems in different noise conditions.
Differential Time-Reversal Tracking Using Independent Component Analysis
Mojtaba Razavian (UCLouvain, Belgium); Mohammad Zoofaghari (University of Amirkabir, Iran); Reza Safian (Isfahan University of Technology, Iran)
This paper discusses imaging and tracking of moving targets in presence of stationary clutters using only one transmitting antenna by independent component analysis(ICA) algorithm and using differential time-reversal technique. This method is done in two case background medium, first in homogeneous background medium and then in three layer medium, i.e. through the wall. There are also other works in through the wall target localization by MUSIC and DORT methods. In these techniques the number of transmitting antenna must be equal or more than the moving and stationary targets. But here by using ICA algorithm only one transmitting antenna and an array of receiving antenna has been used which needs less time for imaging and tracking of targets than MUSIC and DORT methods.
Ground Penetrating Radar Based on Ultrawideband Time-Reversal Method
Sirous Bahramidashtaki (Salman Farsi University, Iran); Javad Ghalibafan (University of Shahrood, Iran)
a new imaging method based on utilization of ultrawideband (UWB) frequency data is proposed for underground target detection. A monostatic antenna is moved over ground surface to acquire the scattering data. The frequency samples of the scattering information are used to form the monostatic data matrix. The singular value decomposition (SVD) of the proposed monostatic scattering matrix is used in DORT (French acronym for decomposition of the time reversal operator) method. The performance of the proposed method is investigated numerically by applying it to discrete scatterers embedded in homogeneous and continuously random inhomogeneous media. The effect of synthetic aperture size on image resolution is studied. It is observed that wider aperture size yields to better focusing resolution.
Comparison of Heuristic UTD Coefficients in an Outdoor Scenario
Diego Tami and Cássio Rego (Federal University of Minas Gerais, Brazil); Dinael Guevara (Francisco de Paula Santander University, Colombia); Andres Navarro (Universidad Icesi, Colombia); Fernando Moreira (Federal University of Minas Gerais, Brazil); Narcis Cardona (The Polytechnic University of Valencia, Spain); Jordi Joan Giménez (Universitat Politècnica de València, Spain)
This paper presents a comparison of three heuristic coefficients for the Uniform Theory of Diffraction (UTD), used to characterize the radiowave scattering in typical urban scenarios. The coefficients were implemented in a propagation model based on 3D ray-tracing techniques for a Digital Video Broadcasting (DVB) service. In order to evaluate each coefficient we analyze the statistical behavior of the mean and standard deviation of the absolute errors between the estimated values and the measured data of path loss in a large number of receptor points in an outdoor scenario.
Assessment of the Shadowing Effect Between Windturbines
The field scattered by a windturbine illuminated by at VOR or radar frequency can affect nearby windturbines depending on the distance between the two windturbines and the frequency. This paper proposes an assessment of the shadowing effects between two windturbines illuminated by a VHF source and at radar frequencies at typical distances. The interactions between the windturbines is shown to be negligible.
Electromagnetic Scattering From Impedance-Matched Bodies
Andrey Osipov (German Aerospace Center (DLR), Germany)
Electromagnetic scattering from impedance bodies with the surface impedance equal to the wave impedance of the surrounding medium shows a number of extremal features, including vanishing axial backscattering cross section in the case of bodies of revolution. This paper examines various scattering cross sections (mono- and bistatic, total scattering, absorption and extinction) of electrically large arbitrarily shaped impedance-matched bodies, and it is shown that the backscattering cross section of arbitrarily shaped convex impedance-matched bodies vanishes in the optical limit. Furthermore, it is conjectured that considered as functions of the surface impedance and for a randomly polarized incident field, the mean total scattering cross section has a global minimum and the mean absorption cross section a global maximum when the surface impedance is matched with the surrounding medium. Similar statements, in terms of corresponding scattering widths, hold for cylindrical impedance bodies.
3D Dielectric Cuboids: An Alternative for High-Resolution Terajets At THz Frequencies
Victor Pacheco-Peña and Miguel Beruete (Universidad Publica de Navarra, Spain); Igor Vladilenovich Minin (Siberian State Academy of Geodesy, Russia); Oleg Vladilenovich Minin (National Research Tomsk State University, Russia)
A mechanism to produce terajets at terahertz frequencies (THz) is numerically and experimentally demonstrated by simply using 3D dielectric cuboids. After evaluating the focusing performance, it is demonstrated that a quasi-symmetric focus is produced just at the output of the 3D cuboid when the refractive index is n=1.41. Moreover, the terajet performance is evaluated experimentally, demonstrating a good agreement with simulation results. Also, by using spherical metallic particles with different diameters, the capability to enhance the backscattering is demonstrated with an enhancement of ~1.53dB and ~10dB for metal particles with diameters d1=0.10 and d1=0.250, respectively.
Electromagnetic Characterization of Inhomogeneous Media Using the State Space Method
Davood Zarifi (University of Kashan, Iran); Homayoon Oraizi and Mohammad Soleimani (Iran University of Science and Technology, Iran)
This paper presents an analytical approach for the electromagnetic characterization of one-dimensional inhomogeneous media. The proposed approach provides the permittivity profile of the medium in terms of the reflection and transmission coefficients. The inverse solution of the permittivity profile is obtained with the help of state transition matrix (STM) and its properties. The advantage of using this analytic reconstruction technique is its ability to remove complexity and nonlinearity of the inverse problem.
Indoor RCS Measurement Facility ARCHE 3D: RCS Multi-Calibration Under Spherical Wave
Pierre Massaloux (CESTA, France)
This experimental layout is composed of a 4 meters radius motorized rotating arch (horizontal axis) holding the measurement antennas while the target is located on a mast (polystyrene or Plexiglas) mounted on a rotating positioning system (vertical axis). The combination of the two rotation capabilities allows full 3D Near-Field monostatic RCS characterization. To correct the gain of instrumentation a calibration method is used; a standard object (like a sphere) is placed at the intersection of the measurement layout axes. But especially in Near-Field, it remains an important error out of the calibration area due to the decrease and sphericity of the electromagnetic waves. This paper compares a new method of calibration based on an experimental correction with the Huygens Lens method. Thanks to many measurements of standard, we are able to perform a multi-calibration method in space domain to reconstruct a RCS measurement in frequency domain.
Time-Variant Scattering Properties of Wind Turbines
Frank Weinmann and Josef Worms (Fraunhofer FHR, Germany)
This paper focuses on the electromagnetic modeling of time-variant scattering effects of wind turbines using a ray tracing approach. The results clearly demonstrate that a static model, as used in many previous reports, is not enough to capture possible interference effects. The simulation results are also supported by measurement data, which have been taken in a real wind turbine environment of a radar system.
Radiation of a Source on a Convex NURBS Surface
Manushanker Balasubramanian (Fraunhofer Institute for High Frequency Physics and Radar Techniques, Germany); Alberto Toccafondi and Stefano Maci (University of Siena, Italy)
In this paper we propose a technique for computing the ray caustic distance parameter on an arbitrary convex surface described by Non-Uniform Rational B-splines (NURBS) surface representation. The ray caustic distance parameter is essential for evaluating the UTD surface diffracted fields that are diffracted from a convex surface. Examples validating the accuracy of the numerical approach proposed are presented.
Impact of the Target Supporting Mast in an Indoor RCS Measurement Facility: Computation and Measurement
Pierre Massaloux (CESTA, France); Genevieve Maze-Merceur (CEA, France)
This experimental layout is composed of a 4 meters radius motorized rotating arch (horizontal axis) holding the measurement antennas while the target is located on a mast (polystyrene or Plexiglas) mounted on a rotating positioning system (vertical axis). The combination of the two rotation capabilities allows full 3D Near-Field monostatic RCS characterization. The main measurement errors are due to the near field illumination, and the influence of the mast on the measured RCS. The first one has been addressed in a previous paper [4]. This paper investigates the influence of the material of the mast supporting the target under test. RCS measurements results of a canonical target are compared to the simulation of its RCS taking account both the near-field illumination and the presence of the supporting mast.
Assessment of Rain Fade Mitigation Techniques for High Throughput Satellites by a Time Series Synthesizer
Roberto Nebuloni (Ieiit - Cnr, Italy); Carlo Capsoni, Marco Luccini and Lorenzo Luini (Politecnico di Milano, Italy)
We assess here the effectiveness of fade mitigation techniques on the user link side of a TLC satellite system by a simulation tool able to generate correlated time series of rain attenuation in multiple sites. A preliminary analysis on two case studies shows that on-board dynamic power allocation coupled with ACM reduces the impact of heavy fades, permits a larger exploitation of efficient MODCODs and equalizes the performance of the user links. However, in the presence of convective cells, co-channel interference can be dominant, hence reducing the benefits of the above techniques.
Low-Cost System Design for Tracking Satellites in Geosynchronous Orbit
Sebastijan Mrak, Urban Kuhar and Andrej Vilhar (Jozef Stefan Institute, Slovenia)
Geosynchronous satellites do not hold a fixed position in the sky like geostationary satellites, but trace out a certain path over the course of a day. This paper presents a design of a low-cost tracking system for keeping track of such satellites. More specifically, the work was inspired by the goal to track relatively small orbital inclinations of the Alphasat. Without such an system, the received signal strength oscillates, especially if a narrow beam antenna is used. The presented design is based on an of-the-shelf camera control unit - a PAN/TILT positioner. While the mechanical characteristics of the system are satisfactory, its control protocol suffers from certain limitations, leading to inaccurate positioning. To compensate this effect, an iterative closed-loop tracking algorithm has been developed. We show experimentally that the proposed system presents an efficient solution.
Wide-Band Characterization of Antennae Plus Aircraft Platform Patterns in L- And Ka-Band
Martin Schwinzerl (Joanneum Research, Austria); Thomas Jost (German Aerospace Center (DLR), Germany); Fernando Pérez-Fontán (University of Vigo, Spain); Michael Schönhuber (Joanneum Research, Austria); Wei Wang (Chang'an University, China); Michael Walter (German Aerospace Center (DLR), Germany); Tanja Pelzmann and Guenther Obertaxer (Joanneum Research, Austria); Nicolas Floury (ESA, The Netherlands); Roberto Prieto-Cerdeira (European Space Agency, The Netherlands)
The aim of the herein presented activities is to improve the quality and reliability of aircraft bound wide-band satellite transmissions for current and up-coming communication- and air-traffic management applications by means of developing simulation tools based upon an improved model for the transmission channel. Among other influences, the effects of the airborne platform itself onto the electromagnetic pattern of airborne antennae for both fixed- and rotary-winged aircrafts have to be assessed and quantified towards the end of inclusion into an updated channel model. Within this paper, the motivation, design and the experimental execution of a series of campaigns involving commercially available, off-the-shelf (COTS) antennae and four different aircrafts (two fixed wing planes and two helicopters) are outlined. Moreover, the experimental execution is described and first results from these measurements are presented.
Slant Path Attenuation At 72.5 and 82.5 GHz
George Brost (Air Force Research Laboratory, USA); Kevin Magde (AFRL, USA)
Slant path brightness temperatures were measured at 72.5 and 82.5 GHz with a multi-channel radiometer. One year of measurements collected at 36° elevation angle in Rome, NY. were examined in terms of the attenuation statistics. A model-based attenuation retrieval algorithm was developed to determine the slant path attenuation cumulative distribution function to over 20 dB of attenuation and to less than 1% exceedance probability. Slant path attenuation was also measured with the radiometer using the sun as a source of radiation. Over 30 dB of attenuation dynamic range was possible with this technique. Sun-beacon measurements were used to test model predictions.
Phase Fluctuations of GPS Signals Associated with Aurora
Irk Shagimuratov (WD IZMIRAN, Russia); Sergey Chernous (PGI, Russia); Iurii Cherniak and Irina Zakharenkova (WD IZMIRAN, Russia); Ivan Efishov (WD IZMIRAN & IKBFU, Russia)
We present the results of investigations of GNSS signal phase fluctuations occurrence during the geomagnetic storm on October 2, 2013. During this space weather event the intense phase fluctuations have been registered at the permanent GNSS stations located not only in auroral and subauroral regions but even over midlatitude stations. In combination with optical and geomagnetic measurements this fact confirms the expansion of the auroral oval towards the equator.
Investigation of Electromagnetic Wave Propagation Through One-Dimensional Plasma Array
Teruki Naito, Kazuo Yamamoto, Shingo Yamaura, Tai Tanaka and Hayato Ogino (Mitsubishi Electric Corporation, Japan); Osamu Sakai (Kyoto University, Japan)
The characteristics of electromagnetic wave propagation through a one-dimensional plasma array were investigated experimentally and by a numerical simulation. Electromagnetic wave was incident normally on the plasma array at the wave frequency from 2 to 18 GHz. Electromagnetic wave was reflected by the plasma array regardless of the polarization when the wave frequency was sufficiently lower than the plasma frequency. Increasing the wave frequency, the reflection of the electromagnetic wave was getting smaller and electromagnetic wave was absorbed only when the electric field was perpendicular to the plasma axis. These results were caused by different schemes of interaction with electric field and electrons in plasma.
Diffraction-induced Early-Time Diffusion of Pulses Propagating Through Scattering Random Media
Elizabeth Bleszynski (Monopole Resesarch, USA); Marek Bleszynski, Dr (Monopole Resaearch, USA); Thomas Jaroszewicz (Monopole Research, USA)
We discuss propagation of short electromagnetic pulses through dilute particulate random media in situations where wave attenuation is dominated by scattering, rather than absorption and scatterers are large compared to the wavelength. Examples of such phenomena include propagation of laser pulses through atmospheric clouds or through sprays in combustion processes. In both cases the medium effects cause serious deterioration of image quality in pulse-based imaging and bandwidth in communication. We propose an approach for alleviating these difficulties. We find that the intensity of a propagating pulse, in addition to the coherent (ballistic) contribution and a long late-time diffusive tail, also exhibits a sharply rising early-time component (attributable to small-angle diffractive part of the scattering cross-section on medium particles) which is attenuated proportionally to the non-diffractive rather than total cross-section, and can be extracted by high-pass filtering of the received pulse, thus facilitating high-resolution range imaging and communication through obscuring media.
Measurements of Horizontal Variations of Radio Refractivity – First Results
Pavel Valtr (Faculty of Electrical Engineering, Czech Technical University in Prague, Czech Republic); Pavel Pechac (Czech Technical University in Prague, Czech Republic); Martin Grabner (Institute of Photonics and Electronics, Czech Republic)
Horizontal variation of radio refractivity is addressed. A measurement campaign was performed by means of a remote controlled airship carrying sensors of temperature, pressure and humidity. The measurement was done over a 13 km long horizontal path at various heights. The path was partly over land and partly over water. The measurements show change of refractivity along the path caused mainly by change of relative humidity of air. Horizontal refractivity gradients calculated range between 0.75 N/km and 2 N/km.
Spatial Correlation of Vertical Gradient of Refractivity on Large Scales
Martin Grabner (Institute of Photonics and Electronics, Czech Republic); Pavel Pechac (Czech Technical University in Prague, Czech Republic); Pavel Valtr (Faculty of Electrical Engineering, Czech Technical University in Prague, Czech Republic)
Spatial distribution maps of the vertical gradient of atmospheric refractivity are derived from a global dataset of meteorological quantities as given by ERA-Interim reanalysis. Spatial correlation of the gradient on large scales is analyzed using data from the European region. The examples of time evolution of the gradient fields are presented and spatial correlation characteristics obtained are discussed.
An Explicit FDTD Scheme for Simulation of Electromagnetic Propagation in Magnetized Cold Plasmas
Yaxin Yu (Chang'an University & College of Electronic and Control Engineering, China); Dongying Li (Shanghai Jiaotong University, China); Qian Li and Ching Eng Png (A*STAR Institute of High Performance Computing, Singapore)
We report in this paper an explicit finite-difference time-domain algorithm for simulating electromagnetic wave propagation in magnetized anisotropic plasmas consisting of electrons, positive, and negative ions. By applying an E-J semi-collocation scheme instead of the full-collocation scheme adopted previously in the implicit model, the tightly coupled governing equations are sufficiently loosened, resulting in a much easier implementation process. The technical details, as well as some numerical results, are to be discussed during the presentation.
Heating Properties of the Resonant Cavity Applicator with Ultrasound Monitoring System for Effective Hyperthermia Treatments
Keito Nakamura (Graduate School of Meiji University, Japan); Yasuhiro Shindo (Toyo University, Japan); Kazuo Kato (Meiji University, Japan)
In this study, we discuss the effectiveness of a resonant cavity applicator with an ultrasound monitoring system. We already proposed a non-invasive heating method using the resonant cavity applicator for hyperthermia treatments, and confirmed the possibility of controlling the heated area and a location of a hotspot. However, this applicator did not have a monitoring system to detect the location and size of the target. In the present paper, to overcome this problem, we propose a monitoring system using a commercial diagnostic ultrasound imaging system. In order to show the validity of the proposed resonant cavity applicator with the ultrasound monitoring system, we reconstructed a 3-D model from 2-D ultrasound images to detect the location and size of the target and to calculate temperature distributions inside a heated object. From these results, we found that the proposed system is useful for effective hyperthermia treatments.
Sensitivity of Tropospheric Scintillation Models to the Accuracy of Radiosonde Data
Carlos Pereira (Spacebel, Belgium); Danielle Vanhoenacker-Janvier (Université catholique de Louvain, Belgium); Chiara Ghiringhelli (Polimi, Italy)
The increase of the frequency of Earth-Low Earth Orbit satellite links leads to the development of new propagation models in order to accurately characterize the propagation channel. Space-time models are developed for tropospheric attenuation and scintillation but their validation is difficult in the absence of measured data. The verification of scintillation models can be performed worldwide against models using radiosonde data. The sensitivity of the propagation model to measurement errors in radiosonde data is critical. This paper shows an analysis of the effect of radiosonde measurement errors on the refractive index structure constant which is the main parameter used in the scintillation models. The next step will be the evaluation of the effect on the scintillation variance cumulative distribution.
UHF Antenna Design for the Estimation of Fiber Density of Steel Fiber Reinforced Concrete
Marta Sanchez, Iván Peña, Amaia Arrinda, David Guerra and Unai Gil (University of the Basque Country, Spain)
Steel Fiber Reinforced Concrete arises when steel fibers are included during the mixture process of the conventional concrete, improving some characteristics of the material as the resistance capacity against heavy efforts. Since this feature of the material depends on the quantity and distribution of fibers inside it, an accurate characterization of these parameters is needed. This paper describes an UHF antenna design for carrying out an estimation of the SFRC fiber density. Details of its characteristics as well as the results obtained from its use in a non-destructive measurement system of the SFRC fiber density are given in the following sections.
High Resolution DOA Estimation for the Air, Marine, and Land Platforms
Ömer Faruk Kip (Gate Electronic Industry and Trade Inc., Turkey); Ozgur Sutcuoglu (GATE Elektronik A. S., Turkey); Okyanus Tulgar and Kadir Durgut (Gebze Technical University & Gate Electronic Industry and Trade Inc., Turkey)
In the radar systems used for the direction of arrival detection, it is required to minimize the spectral estimation errors. In order to achieve this, a large data length or a high sampling frequency is required for the Fast Fourier Transform based spectral estimation techniques. This issue causes important problems in terms of the measurement time, processor, and memory resources. Especially, this problem arises in the applications for air platforms due to the fast movement. By using the introduced algorithm, the direction of arrival estimation is achieved with much better accuracy compared to the traditional technique without increasing the measurement time, processor, or memory resources. This is an important convenience to setup radar systems.
A Novel Collision Avoidance MAC Protocol for Multi-Tag UWB Chipless RFID Systems Based on Notch Position Modulation
Mohamed El Hadidy (FOM University of Applied Science & CST-Middle East, Germany); Ahmed El-Awamry (University of Duisburg-Essen, Germany); Abdelfattah Fawky (University of Duisburg Essen, Germany); Maher Khaliel and Thomas Kaiser (Universität Duisburg-Essen, Germany)
In this work, a novel Notch Position Modulation (NPM) scheme is presented as the first Medium Access Control (MAC) algorithm for handling the multi-tag identification scenario of the frequency signature based chipless RFID tags. This NPM algorithm reduces the sensing and identification time and accordingly the overall system latency. Furthermore, an advanced UWB signaling scheme based on frequency sweeping criteria is designed for the RFID reader in order to make the best use of FCC UWB regulations for increasing the reading range. This protocol provides MAC identity for each chipless RFID tag, enables determining the number of the existing tags, orthogonal modulated signatures for each tag and the corresponding modulation parameters. Moreover, the mitigation of the interference between the several chipless RFID tags and the undesired environmental reflections is a straightforward result of this new protocol.

WS5 R&S: Antenna Measurements at Rohde & Schwarz: The New Test Antenna Chamber

Industrial Workshop
Diogo de Silves (Room 1.08)

Tuesday, April 14 15:00 - 16:20 (Europe/Berlin)

Inv_1A: Invited Speakers Session 1A

Room: Diogo Cão (Aud 8)
Chair: Luca Salghetti Drioli (European Space Agency-ESTEC, The Netherlands)
15:00 Holographic Principles in Antenna Metrology At Millimeter and Submillimeter Wavelengths
Antti V. Räisänen and Juha Ala-Laurinaho (Aalto University, Finland)
Holographic principles used in antenna metrology at millimeter and submillimeter wavelengths are discussed. Holographic principles may be applied either in measurement data acquisition and analysis or in producing the plane wave conditions for the measurement.
15:40 Factors Limiting the Upper Frequency of mm-Wave Spherical Near-field Test Systems
Daniël J Janse van Rensburg (NSI-MI Technologies & Nearfield Systems Inc, USA)
Ongoing development of on-chip antennas operating at mm-Wave frequencies have led to the development of spherical near-field test systems operational at much higher frequencies than before. A natural progression is to apply these systems at even higher frequencies. This paper addresses some of the factors limiting this frequency bound. These include mechanical positioning repeatability, absolute position fidelity, RF sub-system stability, spherical near-field sampling requirements and required far-field distances. Correction techniques that can be employed to enhance the performance of such measurement systems are also considered and evaluated.

Inv_1B: Invited Speakers Session 1B

Room: Pedro A Cabral (Aud 2)
Chair: Danielle Vanhoenacker-Janvier (Université catholique de Louvain, Belgium)
15:00 Combination of Free Space Optics (FSO) and RF for Different Wireless Application Scenarios
Erich Leitgeb and Thomas Plank (Graz University of Technology, Austria)
In this contribution Free Space Optics (FSO) in combination with other wireless technologies (including WLAN and satellite communications) is presented. Modular communication systems are considered, which allows worldwide access to the Internet or other networks by combining satellite communications, FSO, Wireless LAN, Local Multipoint Distribution System (LMDS) and DVB-T (terrestrial digital video broadcast). Wireless LAN offers connectivity to mobile users in a network cell, Free Space Optics allows quick installation of broadband fixed wireless links instead of cables and satellite communications provides a backbone between distant locations in the world. DVB-T is the current video broadcast standard (instead of former analogue TV) and will also be used for Internet-access (see project SEE TV-WEB). Different scenarios (and results) using modular wireless technologies are shown. A brief introduction at the begin shows the advantages and disadvantages of Optical Wireless (also called Free Space Optics, FSO) compared to Fibre and RF technologies.
15:40 Channel Characterization for Unmanned Aircraft Systems
David W Matolak (University of South Carolina, USA)
Unmanned aircraft systems (UAS), also known as unmanned aerial vehicles, or by the misnomer "drones," are seeing explosive growth, and this growth is expected to continue for the foreseeable future. Hence numerous entities are involved with research, design, and testing to ensure safe and reliable UAS operation in the worldwide airspace. Since many UAS will be small and highly maneuverable, air-ground channel conditions will differ from—and often be more challenging than—those of traditional piloted aircraft, where ground sites are in open areas with tall antenna towers. Thus new research is required to accurately characterize the air-ground channel. We provide motivation for accurate air-ground channel characterization and modeling, and briefly define the main characteristics of the air-ground channel. Various channel modeling options are described. We provide example air-ground channel measurement results from our work with NASA, discuss initial air-ground channel models, and future work.

Tuesday, April 14 16:50 - 18:30 (Europe/Berlin)

Bi6 InvScat: Imaging and Inverse Scattering for Biomedical Applications

Room: Pedro A Cabral (Aud 2)
Chairs: Ovidio Mario Bucci (University of Naples, Italy), Oleksandr Malyuskin (Ulster University, United Kingdom (Great Britain))
16:50 The Virtual Experiments: An Emerging Framework for the Effective Solution of Inverse Scattering Problems
Martina Teresa Bevacqua (Università Mediterranea di Reggio Calabria, Italy); Lorenzo Crocco (CNR - National Research Council of Italy, Italy); Loreto Di Donato (University of Catania, Italy); Tommaso Isernia (University of Reggio Calabria, Italy)
In this communication, we discuss the potential and the perspectives of a new and effective framework to tackle the solution of inverse scattering problems. Starting from the statement that (due to the linearity of Maxwell equations) scattering phenomena can be recombined in many different ways, it is possible to design suitable experiments where peculiar properties of the induced fields or sources hold true. These virtual experiments, synthetically built by properly post-processing the available data, provide a convenient framework to recast the inverse problem, wherein the enforced properties can be exploited throughout the solution procedure. Accordingly, this concept is a powerful tool to derive new inversion approaches capable to overcome some of the typical limitations of inverse scattering procedures.
17:10 Resonance Microwave Reflectometry for Early Stage Skin Cancer Identification
Oleksandr Malyuskin (Ulster University, United Kingdom (Great Britain)); Vincent Fusco (Queen's University Belfast, United Kingdom (Great Britain))
A novel contactless, non-invasive early stage skin cancer diagnostic technique based on resonance microwave near field probing is proposed and experimentally evaluated using artificial dielectric skin model. Two types of near field probes - a small helix antenna and a loaded subwavelength aperture are studied in this paper. These near field probes enable very efficient, resonance, electromagnetic coupling to lossy dielectric which results in significant change of reflected off the inhomogeneity (e.g. tumor) signal as compared with the signal scattered off the background (healthy skin). It is shown that the typical resolution of a malignant tumor with a characteristic size of one tenth of the radiation wavelength can be discriminated with at least 6dB amplitude and 50 degrees phase contrast from healthy skin and with more than 3dB contrast from benign lesion of the same size.
17:30 Clinical Microwave Tomography with a Lossy Coupling Bath – Insights Into Challenging Reconstruction Cases
We have rigorously analyzed the computed amplitude and phase projections as they evolve during the progression of the iterative, log transformed image reconstruction process especially in breast imaging. In cases where the overall tissue permittivity is less than that for the surrounding background, the phase and amplitude projections are always well-behaved with the phase components tending less than zero, and the reconstruction process proceeds in a predictable and efficient manner. However, in situations where the tissue properties exceed those of the background, the phase and amplitude projections appear more uneven with the permittivity portion exhibiting mostly positive phase values often with sharp jumps immediately on either side of the principle feature. For these targets, the recovery process is more uneven. In this report we examine the nature of these challenging cases and propose a set of strategies to deal with them systematically while not arbitrarily biasing the final solution.
17:50 On the Design of Exposure Systems for Medical Applications of Microwaves
Ovidio Mario Bucci (University of Naples, Italy); Lorenzo Crocco (CNR - National Research Council of Italy, Italy); Rosa Scapaticci (CNR-National Research Council of Italy, Italy)
Microwave exposure devices based on conformal array configurations are exploited in biomedical applications for both diagnostic and therapeutic purposes. In this framework, one important aspect worth to be addressed is the minimization of the number of the adopted probes, in order to minimize costs and dimensions of the system, as well as time of exposure. In this communication, we generalize a methodology recently proposed by the authors to design optimal devices for magnetic nanoparticles enhanced microwave imaging of breast cancer and show how exploit it to optimize exposure systems in several cases, such as follow-up, therapy monitoring and hyperthermia.
18:10 Imaging of Intracranial Tissues with Radio Waves
Yoshihiko Kuwahara (Shizuoka University, Japan)
This report presents the possibility of visualizing the organizational structures of the complex human body by solving the inverse scattering problem. A two-dimensional model was used to simplify analysis. The scattered strength distribution cannot be used to reconstruct the intracranial organizational structures despite the use of a coupling liquid, but the dielectric constant and conductivity distribution of the organs can be reconstructed exactly with the inverse scattering problem without a coupling liquid.

C13 Graphene: [C] Applications of Graphene and Novel Materials at Terahertz and Microwaves

Antennas/Bridging other Areas
Room: Diogo Cão (Aud 8)
Chairs: Yang Hao (Queen Mary University, United Kingdom (Great Britain)), Raj Mittra (Penn State University, USA)
16:50 Graphene Magnetoplasmonic Principles, Structures and Devices
Nima Chamanara and Christophe Caloz (Ecole Polytechnique de Montreal, Canada)
This paper recalls fundamentals of magnetoplasmons in magnetically biased graphene structures, describes their non-reciprocity and demonstrates their utilization as devices such as isolators and couplers. A multi-scale multi-physics structure, using a magnetic nanowire membrane as integrable magnetic bias, with applications to Faraday rotators and integrable nonreciprocal plasmonic components, is presented.
17:10 Entanglement of Two-Level Atoms Above Graphene
Andrei Nemilentsau (University of Wisconsin-Milwaukee, USA); Seyyed Ali Hassani Gangaraj (University of Wisconsin-Milwaukee); George Hanson (University of Wisconsin-Milwaukee, USA); Stephen Hughes (Queen's University, Canada)
Using the quantum master equation, we demonstrate entanglement of two-level atoms (TLAs) over graphene. Graphene, acting as a structured photonic reservoir, significantly modifies the spontaneous decay rate of a TLA, and is rigorously incorporated into the formalism through the classical electromagnetic Green dyadic. Moreover, entanglement between the TLAs can be improved compared to the vacuum case, due to coupling of the TLAs to TM surface plasmons on graphene. Dynamics of TLAs can be further controlled by graphene biasing.
17:30 Theoretical Limits of Graphene Terahertz Non-Reciprocal Devices
Michele Tamagnone (Ecole Polytechnique Fédérale de Lausanne, Switzerland); Arya Fallahi (IT'IS Foundation, Switzerland); Juan R Mosig (Ecole Polytechnique Federale de Lausanne, Switzerland); Julien Perruisseau-Carrier (Ecole Polytechnique Fédérale de Lausanne & EPFL, Switzerland)
The potential of graphene for use in non-reciprocal terahertz applications was evidenced by recent demonstrations of the Faraday rotators and microwave isolators. These promising yet preliminary results raise crucial questions: what is the optimal performance achievable by more complex designs using multilayer structures, graphene patterning, metal additions, or a combination of these approaches, and can this optimum design be achieved in practice? We provide an answer to these questions by showing the existence of an upper bound on the performances of passive graphene non reciprocal devices, and we show optimal designs able to reach these performances. The bound depends uniquely on the conductivity of graphene under magnetic bias, and hence enables an estimation of the best possible performances prior to any design. We believe that these results constitute an important roadmap for future devices based on graphene's non-reciprocity
17:50 Techniques for Reducing the SAR in Mobile Devices by Using Graphene-Type Absorbing Materials
Chiara Pelletti (The Pennsylvania State University, USA); Long Li (Xidian University, China); Mohammed Abdel-Mageed (Pennsylvania State University, USA); Giacomo Bianconi and Raj Mittra (Penn State University, USA)
Given the well documented health effects of electromagnetic radiation on humans, the SAR reduction techniques are becoming increasingly relevant to the industry. However, satisfying the bandwidth, efficiency, size and cost requirements of a low SAR solution for the new mobile terminals remains elusive to-date. This paper presents a method for designing an SAR shield, based on combined use of graphene-type absorbing cards and metal sheets, to reduce the SAR below the allowable limits. Illustrative results for several test examples are presented in order to show how the size and position of the card influences the SAR reduction level, and how we manage to reduce the SAR levels without sacrificing the antenna efficiency significantly.
18:10 Linear and Nonlinear Microwave Characterization of CVD-Grown Graphene Using CPW Structure
Mingguang Tuo (University of Arizona, USA); Si Li (University of Science and Technology of China, China); Dongchao Xu and Min Liang (University of Arizona, USA); Qi Zhu (University of Science and Technology of China, China); Qing Hao and Hao Xin (University of Arizona, USA)
The linear and nonlinear microwave properties of chemical vapor deposition (CVD) grown graphene are characterized in this work by using a co-planar waveguide (CPW) structure. The intrinsic properties of the graphene are extracted and fitted with an equivalent circuit model. The nonlinear properties of the graphene are also measured and will be used for determining the thermal properties of graphene.

C23 MultiB: [C] Emerging techniques for multiband and wideband antennas

Room: Bartolomeu Dias (Aud 4)
Chairs: Toru Kawano (National Defense Academy, Japan), Hisamatsu Nakano (Hosei University, Japan)
16:50 A Bent-Ends Spiral Antenna Above a Fan-Shaped Electromagnetic Band-Gap Structure
Masahiro Tanabe (Toshiba Infrastructure Systems & Solutions Corporation, Japan)
This paper describes radiation characteristics of a bent-ends two-arm Archimedean spiral antenna above a fan-shaped electromagnetic band-gap (EBG) structure. The EBG structure consists of fan-shaped EBG patch cells. The fan-shaped EBG patches are set to be homogeneous in the circumferential direction but are set to be inhomogeneous in the radial direction. The analysis is performed using the method of moment. It is revealed that wideband radiation characteristics, including input impedance and axial ratio, are mitigated when the fan-shaped EBG structure is adopted.
17:10 Development of Reconfigurable Multiple Wideband Antenna for Radar and Monitoring Applications
Cristina Borda Fortuny and Amin Amiri (UCL, United Kingdom (Great Britain)); Kin-Fai Tong (University College London, United Kingdom (Great Britain))
Two ultra-wideband frequency agile antennas are proposed for radar and wireless spectrum monitoring applications. The first one is based on an ultra-wideband antenna that reduces its bandwidth using frequency-dependant components to get a four-band switchable antenna, while the second one uses a shared antenna aperture and achieves three bands, both antennas maintaining the radiation characteristics in all their bands.
17:30 Numerical Analysis of a Grid Array Antenna Radiating a Linearly Polarized Dual-Beam
Toru Kawano (National Defense Academy, Japan); Hisamatsu Nakano (Hosei University, Japan)
The radiation characteristics of a grid array antenna for one-line excitation are investigated using the method of moments. This grid radiates a dual-beam. It is revealed that the co-polarized electric field components are the same in the two principal planes. The direction of maximum radiation and the gain are discussed.
17:50 A Wide-Band Wide-angle Scanning Phased Array with Pattern Reconfigurable Square Loop Antennas
Amit Mehta (Swanse University, United Kingdom (Great Britain)); Rob Lewis (BAE Systems Applied Intelligence Laboratories, United Kingdom (Great Britain)); Nathan Clow (Dstl, United Kingdom (Great Britain)); Arpan Pal (Swansea University, United Kingdom (Great Britain))
In this paper we present a 2×2 phased array system consisting of beam reconfigurable Square Loop Antenna (SLA) as its unit element. Each SLA has four feeding ports and can provide four off bore-sight tilted beams (8.6dBi at θmax=32°) in four quadrants of space. It is demonstrated that these four tilted beams can be combined together to offer a reconfigurable phased array system. In comparison with a resonant antenna based approach the proposed system has the potential to offer a wider bandwidth, wider angular scanning, lower grating lobes and a deeper null steering.
18:10 Metamaterial-Based Wideband Shorting-Wall Loaded Mushroom Array Antenna
Wei E. I. Liu (National University of Singapore, Singapore); Xianming Qing (Institute for Infocomm Research, Singapore); Zhi Ning Chen (National University of Singapore, Singapore)
A shorting-wall loaded metamaterial mushroom antenna is proposed for bandwidth enhancement and compact design. Owing to the shorting-wall loading, the lower frequency region of the right-handed branch of the composite right/left-handed (CRLH) mushroom structure is exploited. The operating modes of the antenna are investigated. The antenna prototype at 5-GHz band exhibits 26% impedance bandwidth (|S11|<−10 dB) with a compact size of 0.65λ0 x 0.61λ0 x 0.06λ0 (λ0 is the center operating wavelength in free space).

C25 Inkjet: [C] Inkjet Printed Antennas for Flexible, Wearable and Large Area Electronics

Antennas/Multi Applications
Room: Paulo da Gama (Pav 5B)
Chairs: Benito Sanz-Izquierdo (University of Kent, United Kingdom (Great Britain)), Atif Shamim (King Abdullah University of Science and Technology, Saudi Arabia)
16:50 Inkjet Printing for the Fabrication of CPW Antennas and Frequency Selective Surfaces
Thierry Monediere (University of Limoges & CNRS, France); Eric Arnaud (University of LIMOGES, France); Dominique Baillargeat, Nicolas Delhote and Marc Thevenot (XLIM, UMR CNRS n°7252, University of Limoges); Eloi Beaudrouet, Chrystelle Dossou-yovo and Rémi Noguéra (CERADROP, France)
This paper presents a solution to bypass the cost and flatness problems for low-cost electronic devices which is the inkjet printing. This process allows the use of flexible substrate materials, such as paper or plastics, suitable for a reel-to-reel process. More precisely, the procedure to design an Electromagnetic Band Gap (EBG) antenna using Frequency Selective Surfaces (FSS) and Coplanar Wire-Patch (CWP) antenna for 2.5 GHz applications is detailed. This kind of antenna has been designed before, but the used substrate is expensive and thin. These antennas were fabricated using inkjet-printing technology on a flexible, low-cost paper substrate using a simple, fast and cheap process compared to the photolithography technology. The design characteristics of the antennas were verified and the experimental measurements were successfully compared to the simulated ones.
17:10 A 3D Printed Microstrip Patch Antenna
Garret McKerricher (Three D Systems & King Abdullah University of Science and Tech, Saudi Arabia); Don Titterington (Three D Systems (3DSystems), USA)
In this work a circular patch antenna is demonstrated using inkjet printing. The antenna is printed using a commercial 3DSystems Projet 5500 printer with acrylate based ultraviolet curable polymer. The antenna is metallized using silver nanoparticle ink with a Dimatix 2831 inkjet printer and 10pl disposable cartridges. Compared with other commonly used 3D printing technologies such as fused deposition modeling we are able to achieve smooth dielectric surfaces with root mean square roughness of ~100 nm. Complex internal patterns can be created with MJP and a honeycomb inspired substrate has been fabricated. Not only does this concept reduce the weight and loss of the antenna it can also be used to control and engineer the dielectric constant of the material. Simulations show that the radiation efficiency can be improved by more than 10% by using the honeycomb structure.
17:30 Parametric Optimization of Inkjet Printing and Optical Sintering of Nanoparticle Inks
Erja Sipilä and Yanan Ren (Tampere University of Technology, Finland); Johanna Virkki (Tampere University, Finland); Lauri Sydänheimo (Tampere University of Technology, Finland); Manos M. Tentzeris (Georgia Institute of Technology, USA); Leena Ukkonen (Tampere University of Technology, Finland)
In this paper, the parameters for inkjet-printing and photonic sintering of silver and copper nanoparticle inks on flexible polyimide substrate were studied by manufacturing simple line patterns. The results were then utilized to manufacture passive ultra high frequency (UHF) radio frequency identification (RFID) tag antennas on polyimide substrate. The tag's performance was evaluated by wireless measurements. Tags achieved peak read ranges of 3.6-5.5 meters, which can be considered suitable for practical applications.
17:50 Tunable Inkjet-Printed Slotted Waveguide Antenna on a Ferrite Substrate
Ahmed Nafe (King Abdullah University of Science and Technology (KAUST), Saudi Arabia); Muhammad Fahad Farooqui (Concordia University, Canada); Atif Shamim (King Abdullah University of Science and Technology, Saudi Arabia)
In this work an inkjet-printed frequency-tunable slotted waveguide antenna on a ferrite substrate is reported. Unlike the typical substrate integrated waveguide approach with via holes, a true 3D rectangular waveguide is realized by inkjet printing of nano-particle based conductive ink on the broad faces as well as on sides of the substrate. The operating frequency of the antenna can be tuned by applying a variable static bias magnetic field that controls the permeability of the host ferrite substrate. The antenna operates about a center frequency of approximately 14.75 GHz with an instantaneous impedance bandwidth of 75 MHz. Simulations show that a tuning range of 10% (1.5 GHz) is achievable with this antenna using a bias magnetic field of 2 kOe yielding it especially attractive for tunable and reconfigurable yet low cost microwave systems.
18:10 A Low-cost Inkjet-printed Microfluidics-based Tunable Loop Antenna Feed by Microfluidics-based Tunable Balun
Wenjing Su (Georgia Institution of Technology, USA); Benjamin Cook and Manos M. Tentzeris (Georgia Institute of Technology, USA)
A low-cost and disposable loop antenna is proposed, which consists of a microfluidic tunable square loop and a microfluidic tunable balun to guarantee same radiation pattern with reconfigurable frequency. By embedding partial loop and balun under different fluids, the proposed antenna can achieve a frequency range of 2.28 GHz for water filled channel to 2.42 GHz for empty channel with the help of inductive sensing. The proposed antenna is fabricated in low-cost and non-cleanroom process by integrating inkjet-printing with laser-etching techniques. This antenna can be used as a fluid sensor as well as a tunable antenna. The microfluidics balun embedded can be applied independently as a wideband balun.

C28 MMIMO: [C] Massive MIMO for 5G broadband communication networks

Antennas/Cellular Communications
Room: Pêro Escobar (Pav 3A)
Chair: Vanja Plicanic Samuelsson (Sony Mobile Communications, Sweden)
16:50 On the Antenna Array Gain in Geometrical Ray Based Stochastic Channel Models
Mattias Gustafsson (Huawei Technologies Sweden AB, Sweden); Martin Alm (Huawei Technologies, Sweden)
Geometrical ray based stochastic channel models are popular and efficient tools to predict and estimate the potential of wireless systems given some system inputs, such as baseband precoding and decoding capabilities, bandwidths, antenna element designs and antenna array configurations. It has been identified though that the electromagnetic effects of antenna array gain may lead to inaccurate results of the channel matrix coefficients. In this article we introduce array gain normalization of the H-matrix link and analyze the results with the channel model.
17:10 Analysis of Massive MIMO with Hardware Impairments and Different Channel Models
Fredrik Athley (Ericsson AB, Sweden); Giuseppe Durisi (Chalmers University of Technology, Sweden); Ulf Gustavsson (Ericsson AB, Sweden)
Massive Multiple-Input Multiple-Output (MIMO) is foreseen to be one of the main technology components in the next generation of cellular communications (5G). In this paper, fundamental limits on the performance of downlink massive MIMO systems are investigated by means of simulations and analytical analysis. Multi-user MIMO signal-to-noise-and-interference ratio (SINR) and sum rate for a single-cell scenario are analyzed for different array sizes, channel models, and precoding schemes. The impact of hardware impairments on performance is also investigated. Simple approximations are derived that show explicitly how the number of antennas, number of served users, transmit power, and size of hardware impairments affect massive MIMO performance.
17:30 Dual-polarized Turning Torso Antenna Array for Massive MIMO Systems
Runbo Ma (MPI-QMUL Information System Research Centre, China); Yue Gao (University of Surrey, United Kingdom (Great Britain)); Clive Parini (QMUL, United Kingdom (Great Britain)); Laurie Cuthbert (Macao Polytechnic Institute, Macao)
A compact dual-polarized antenna with four radiating square patches is presented and arranged to establish an array for massive MIMO systems operating at 3.6GHz. There are three stack levels of orthohexagonal rings in the array and each ring contains six sub-arrays with a gain of 16.6dBi and half-power beam width of 12.5° in azimuth. Within a volume of 8λ×8λ×3λ, the maximum mutual coupling level between any two ports in the array is lower than -29.8dB. With the steerable feature of each beam formed by sub-array, the proposed array can generate 18 beams covering around a whole circumference.
17:50 UE Antenna Properties and Their Influence on Massive MIMO System Performance
Erik L Bengtsson (Sony Mobile, Sweden); Fredrik Tufvesson and Ove Edfors (Lund University, Sweden)
The use of large-scale antenna arrays can bring substantial improvements both in energy and spectral efficiency. This paper presents an initial study of user equipment (UE) antenna performance based on prototypes for a massive MIMO test bed. Most publications in the massive MIMO area have assumed isotropic or dipole antenna behavior at the UE side. It is, however, of greatest interest to evaluate the impact of realistic antenna implementations and user loading on such systems. Antennas are integrated into realistic UE form factors. Simulations are carried out to evaluate system performance using the UE antenna behavior measured in a Satimo StarGate 64. Comparisons are made with ideal isotropic un-correlated antennas. The presented UEs are designed for the 3.7 GHz band used by the LuMaMi massive MIMO test bed at Lund University.
18:10 28 GHz Propagation Analysis for Passive Repeaters in NLOS Channel Environment
Byungchul Kim, Hyunjin Kim, Dongkyu Choi, Youngju Lee, Wonbin Hong and Jeongho Park (Samsung Electronics, Korea (South))
This paper presents an extensive indoor radio propagation characteristics at 28 GHz office environment. A full 3D ray tracing simulation results are compared with measurement results and features high correlation. Means of differences between simulation and measurement are 5.13 dB for antenna 1 and 4.51 dB for antenna 2, and standard deviations are 4.03 dB and 3.11 dB. Furthermore novel passive repeaters in both indoor and outdoor environments are presented and compared. The ray tracing simulation procedures for repeaters are introduced.

C38 Array: [C] Non-Uniform and Sparse Antenna Arrays - Innovative Concepts and Technological Solutions

Room: Tristão V Teixeira (Pav 5A)
Chairs: Ioan E. Lager (Delft University of Technology, The Netherlands), Giacomo Oliveri (University of Trento & ELEDIA Research Center, Italy)
16:50 An Innovative Strategy for the Fast Design of Maximally-Sparse Arrays with Sum and Difference Phase-Only Reconfigurable Fields
Andrea Francesco Morabito (University Mediterranea of Reggio Calabria, Italy)
We present a new and flexible strategy for the synthesis of one-dimensional reconfigurable arrays generating sum and difference power patterns. Aiming at minimizing the related beam forming network's complexity, the design procedure has been conceived in such a way that just a π phase shift (over half antenna aperture) is required to switch from the sum to the difference radiation modality and vice versa. Moreover, in order to minimize the number of active elements, a Compressive-Sensing-inspired engine has been inserted in the design algorithm. The overall synthesis has been formulated as a Linear Programming problem, with the inherent advantages in terms of both computational burden and solution optimality. The given theory is supported by a numerical example concerning a couple of reconfigurable fields with wide scanning capabilities for radar applications.
17:10 Beamforming in Sparse, Random, 3D Array Antennas with Fluctuating Element Locations
Mark J. Bentum (University of Twente, The Netherlands); Ioan E. Lager, Sjoerd Bosma, Wessel Bruinsma and Robin Hes (Delft University of Technology, The Netherlands)
The impact of the fluctuations in the locations of elementary radiators on the radiation properties of three-dimensional (3D) array antennas is studied. The principal radiation features (beamwidth, side-lobes level) are examined based on illustrative examples. Some atypical behaviours, that are specific to 3D arrays, are highlighted. The effect of fluctuations is also demonstrated via examples. This study is important, among others, for designing beamforming strategies in case of constellations of (nano) satellites for space-bound remote sensing of the Earth and the Universe.
17:30 Array Tracing: a Graphical-Deterministic Procedure for the Synthesis of Linear Sparse Arrays
Giovanni Toso (European Space Agency, ESA ESTEC, The Netherlands); Piero Angeletti (European Space Agency, The Netherlands)
A graphical-deterministic procedure for the synthesis of linear sparse arrays is presented. The procedure is based on a quasi-analytical null-matching strategy allowing designing linear arrays with an arbitrary number of elements. The elements of a linear array may be graphically traced using, as a supporting frame, a continuous curve representing the complex cumulative signature of a reference pattern visualized in a null direction
17:50 Compressive Sensing Technique for Multi-Frequency Sparse Linear Array Design
Lorenzo Poli (ELEDIA Research Center, University of Trento, Italy); Nicola Anselmi and Matteo Carlin (University of Trento, Italy); Paolo Rocca (University of Trento & ELEDIA Research Center, Italy)
The synthesis of multi-frequency sparse linear antenna arrays is addressed through the use of an innovative technique based on the multi-task Bayesian Compressive Sensing (MT-BCS). The definition of the array element locations as well as the values of the excitation weights are optimized such to generate the same reference beam pattern at all the desired frequencies. Preliminary results are reported and discussed in order to validate the proposed approach and to show its effectiveness in dealing with the synthesis problem at hand.
18:10 Mutual Coupling Analysis of Large Irregular Arrays: From Multipole to Interpolatory Methods
Quentin Gueuning, Eloy de Lera Acedo and Edgar Colin-Beltran (University of Cambridge, United Kingdom (Great Britain)); Christophe Craeye (Université Catholique de Louvain, Belgium)
A novel formulation is proposed for the multipole expansion, called Laurent series formulation. It finds applications to the fast calculations of integral reactions between Macro Basis Functions in large planar irregular arrays of identical elements. Indeed, it automatically provides the coefficients of the harmonic-polynomial model of the reactions. A better understanding is also achieved for the minimized impact of the so-called low-frequency breakdown when computing interactions at small distances with the interpolatory method.

C41 PropBuilt: [C] The IET session on Propagation in the built environment

Propagation/Wireless Networks
Room: Afonso de Albuquerque (Pav 3B)
Chairs: Clare Allen (Ofcom, United Kingdom (Great Britain)), Pavel Pechac (Czech Technical University in Prague, Czech Republic)
16:50 Investigation of the Use of Absorbing Materials for Indoor Co-Channel Applications
Kenneth Lee Ford (University of Sheffield, United Kingdom (Great Britain))
This paper presents an investigation of the use of absorbing materials for indoor communications applications. Full field simulations of a floor of a building including a conductive obstruction (lift shaft) are given and Signal to Interference/Noise calculations are provided for 2.45GHz. The results show that absorbing materials that can offer a reflection coefficient of -20dB can provide SINR>25dB for over 80% of the Non-Line of Sight area in the structure considered.
17:10 Engineering Indoor Wireless Communication Systems with High Capacity
Michael J Neve and Kevin W Sowerby (The University of Auckland, New Zealand)
The effect of wall attenuation on the uplink per- formance of an interference limited indoor wireless communi- cation system is investigated. An indoor environment containing multiple co-channel access points is investigated for connections made on the basis of strongest signal and for varying intervening wall attenuations. Power balancing is used to equalize signal- to-interference ratios (SIRs), and performance assessed by the reuse probability which quantifies the probability that two or more mobiles at randomly chosen locations can successfully share the channel. Results obtained show that even moderate wall attenuations (10–15 dB) can produce practically useful performance gains.
17:30 The Impact of Thermally Insulating Products on Building Penetration Loss Between 100 MHz and 6 GHz
Richard Rudd (Plum Consulting Ltd, United Kingdom (Great Britain)); Ken Craig (Signal Science Ltd, United Kingdom (Great Britain)); Martin Ganley (BRE, United Kingdom (Great Britain))
There is an increasing use of thermally-insulating materials in the built environment. The impact of these materials on building entry loss at radio wavelengths is of importance to system planners. This paper describes measurements recently made UK to quantify the impact of such materials at frequencies between 0.1 and 6 GHz, in two buildings of traditional construction.
17:50 Indoor Collaborative Localization Method Based on Ultra-Wideband Ranging
Cai Haofan and Guang Wu (South University of Science and Technology of China, China); Yifan Chen (University of Waikato & University of Electronic Science and Technology of China, New Zealand); Jiang Linshan (South University of Science and Technology of China, China)
The Ultra-Wideband (UWB) technology has been proved as a promising indoor localization technique due to its sub-nanosecond (ns) narrow pulse feature offering high timing resolution. However, the accuracy of UWB localization in Non-Line-of-Sight (NLOS) environments, which most commonly exist in indoor constructions, is much lower than that in Line-of-Sight (LOS) environments. In this paper, we propose a collaborative localization algorithm to improve the localization accuracy in NLOS environments by maximally utilizing the LOS links among nodes with unknown locations, and evaluate the localization performance of our proposed algorithm by deploying UWB devices in a typical indoor office environment. The experiment results show that our proposed collaborative method has a better localization performance as compared to other indoor localization methods.
18:10 Analysis of the Propagation Attenuation From Large Buildings in Broadcasting Services
Mario Orefice (Politecnico di Torino, Italy)
The effects of large buildings on the propagation of radio waves are considered, in particular at the most commonly used terrestrial broadcasting frequencies (VHF or lower UHF). A numerical full wave analysis of the transmissions and scattering of complete buildings has been carried out and results are presented, showing is some cases a reduced attenuation and a considerable transparency.

C8 AMTA2: [C] AMTA/EurAAP Measurements of integrated antennas at mm-wavelengths

Measurements/High Data-rate Transfer
Room: Gonçalo V Cabral (Pav 5C)
Chairs: Zhi Ning Chen (National University of Singapore, Singapore), Antti V. Räisänen (Aalto University, Finland)
16:50 77-GHz Integrated Antenna with Plano-Convex Lens: Design and Measurement
Siew Bee Yeap and Xianming Qing (Institute for Infocomm Research, Singapore); Zhi Ning Chen (National University of Singapore, Singapore)
A 77-GHz four-beam plano-convex lens antenna with SIW slot feed for automotive radar is presented. The primary feed consists of four substrate integrated waveguide (SIW) slots which are designed with complete routing and SIW to grounded co-planar waveguide (GCPW) transition. The transition is designed for the integration with a 3D embedded wafer level ball grid array (eWLB) module as well as for onwafer probing measurements, respectively. The antenna prototype at 77 GHz achieves the gain of 24 dBi and a combined beam coverage of ±12o. The simulated and measured results agree quite well
17:10 Design and Measurement of Integrated Antenna with a Plastic Lens for 60 GHz Wi-Gig Applications
Bisognin Aimeric (University Nice-Sophia Antipolis); Aykut Cihangir (University of Nice Sophia Antipolis, France); Cyril Luxey (University Nice Sophia-Antipolis, France); Gilles Jacquemod (University of Nice, France); Romain Pilard (STMicroelectronics, Technology R&D, STD, TPS Lab, France); Frédéric Gianesello (STMicroelectronics, France); Jorge R. Costa (Instituto de Telecomunicações / ISCTE-IUL, Portugal); Carlos A. Fernandes (Instituto de Telecomunicacoes, Instituto Superior Tecnico, Portugal); Eduardo B. Lima (Instituto de Telecomunicações & Instituto Superior Técnico, Portugal); Chinthana J Panagamuwa and William Whittow (Loughborough University, United Kingdom (Great Britain))
An antenna integrated with a dielectric lens for Wi-Gig applications at 60GHz is proposed in this paper. A low-cost lens, manufactured with 3-D printing technology, is used to shape the 3-D radiation pattern of the antenna accordingly to the requirements for typical indoor high-frequency communications. The antenna-lens combination has a measured return loss above 11.5dB between 57-66GHz. The antenna has a maximum gain of 11dBi. If we consider higher gains than 5dBi, we have respectively a 24° and 96° beamwidth in the elevation and azimuth planes.
17:30 Wide Band Electrical Parameter Measurement by Absorber Pasted Ridged Horn Antenna
Hiroyuki Arai (Yokohama National University, Japan)
Wide band electrical parameter measurement for thin material samples is presented by two identical ridged waveguide horn antennas facing each other to propagate quasi-TEM mode between ridges. To suppress multi-reflection inside horns, absorber sheets put on the walls are designed to minimize standing wave in the waveguide. We demonstrate wide band shielding effectiveness measurements and show the method to find electrical parameters of the materials by proposed system.
17:50 A Complete Measurement System for Integrated Antennas At Millimeter Wavelengths
Mohammad Mosalanejad (KU Leuven & IMEC, Belgium); Steven Brebels (IMEC, Belgium); Ilja Ocket (IMEC & ESAT-TELEMIC, KU Leuven, Belgium); Vladimir Volski (KU Leuven, Belgium); Charlotte Soens (Imec, Belgium); Guy Vandenbosch (Katholieke Universiteit Leuven (KU Leuven), Belgium)
An integrated high dynamic range approach is presented to accurately measure the radiation pattern, the scattering parameters, and the gain of integrated on-wafer antennas operating in the millimeter-wave frequency band. RF probes are used to connect to the antenna. This measurement system is specially designed to avoid scattering and parasitic radiation of RF probes in order to increase the dynamic range of the measurements. The mm-wave frequency band is split into two with each band having its own conceptual solution, and a special gain measurement technique is foreseen. The proposed system shows at least a 20 dB increment in the measurement dynamic range. The setup is intended to work between 30-90 GHz.
18:10 Reflection Coefficient Method for Characterizing Antennas on Probe Stations
Ville Viikari (Aalto University & School of Electrical Engineering, Finland); Zhou Du (Nokia Bell Labs, Finland); Vasilii Semkin (VTT Technical Research Centre of Finland, Finland); Juha Ala-Laurinaho and Antti V. Räisänen (Aalto University, Finland)
This paper studies the recently introduced reflection coefficient-based method for antenna characterization. The method necessitates repeating the reflection coefficient measurement under different reflective loads in the near-field of the antenna under test. In this paper, we study the suitability of the method to characterize an antenna on a probe station. We show the measurement results performed at 60 GHz and discuss the further development needs to the method.

MA10 UWBAnt: UWB antennas and time-domain techniques

Antennas/Multi Applications
Room: Gil Eanes (Aud 3)
Chairs: Antonio Lazaro (Universitat Rovira i Virgili, Spain), Pedram Mousavi (University of Alberta, Canada)
16:50 Radar Target Discrimination with Extinction Pulses Using Exponential Β-Splines
Manuel Morante and David Blanco (University of Granada, Spain); María C. Carrion (Dpto Fisica Aplicada, Facultad de Ciencias, University of Granada, Spain)
In this paper, a new contribution to radar-target identification via extinction-pulse method (E-pulse) is developed. The aim of this work consists in the study of a new type of E- pulses in order to improve their discrimination capability for different noisy conditions. This new E-pulses are built using exponential-splines, which are a new type of base functions that has not been used before. The exponential-splines include by definition some free parameters which can be adjusted, for this reason these are good candidates to improve the discrimination capability respect to other type of E-pulses studied in the bibliography.
17:10 UWB Antenna Array for Level and Permittivity Measurement with Calibrated Layer Stripping
Adam Maunder, Omid Taheri, Mohhamad Reza and Pedram Mousavi (University of Alberta, Canada)
The measurement of liquid level and material identification using ultra-wideband radar is an active area of research. A calibrated layer stripping technique for multilayer height and permittivity identification is outlined in this paper. The use and design of an array that improves the detection accuracy and the layer stripping algorithm with an array is detailed. The use of an ultra-wideband array to reduce the signal correlation and fidelity for off-broadside angles and the use of a computationally simple algorithm that characterizes path-loss and near field antenna characteristic for accurate amplitude-distance prediction are unique aspects of this work. The designed Vivaldi antenna and array are characterized in terms of gain. The measurement of a multilayer set-up consisting of canola oil on marble demonstrating the prediction accuracy is given proving the validity of the method.
17:30 UWB Body-Implantable Antenna for Short Range Communication
Joao M. Felicio (Instituto de Telecomunicações, Portugal); Carlos A. Fernandes (Instituto de Telecomunicacoes, Instituto Superior Tecnico, Portugal); Jorge R. Costa (Instituto de Telecomunicações / ISCTE-IUL, Portugal)
An new ultrawideband body-implantable antenna is proposed for low-power, very high data-rate short-range communication with an external near-field device. It is a single layer slot-based printed antenna with 15 mm diameter. The antenna is intended for impulse radio using the 1.4 GHz to 4.2 GHz frequency range. The antenna design and experimental tests considered that it was immersed in a liquid phantom with electrical properties similar to the muscle. Simulated and measured input reflection results were compared with good matching. The time domain analysis shows low pulse distortion, suitable for high data rate communications up to about 1.43 Gbps gross bit rate.
17:50 Polarization Performance of Log-Periodic Antennas on Top of Different Types of Ground Plane; the SKA-low Instrument Case
Eloy de Lera Acedo (University of Cambridge, United Kingdom (Great Britain)); Benedetta Fiorelli (European Space Agency, The Netherlands); Michel Arts (ASTRON, the Netherlands Institute for Radio Astronomy, The Netherlands)
In this paper we discuss the polarimetric performance of log-periodic antennas for low frequency radio astronomy applications. We do this in the framework of the SKA-low instrument, the largest aperture array at m and cm wavelengths to be built by the end of this decade. When a log-periodic antenna, such as the ones to be used in SKA-low are sitting on top of a large ground plane, their polarimetric performance changes with respect to case of the antenna in free space. We discus therefore this effects and their dependency on the ground plane conductivity (ie. metallic ground plane versus lossy ground).
18:10 Forward/backward Coupled Ring Based Phasers for Real-Time Signal Processing
Shulabh Gupta (Carleton University, Canada); Bakhtiar Khan and Christophe Caloz (Ecole Polytechnique de Montreal, Canada)
A backward and forward coupled ring transmission line all-pass phasers are presented, and their general characteristics, operation principles and typical group characteristics are discussed using ideal circuit simulations. The first configuration is based on contra-directional (backward) coupling, which is perfectly TEM, while the second configuration is based on non-TEM co-directional (forward) coupling, which is the radio frequency counterpart of the optical ring resonator coupling. Compared to conventional end-connected coupled-line phasers, the group delay swings of the proposed phasers are inversely proportional to the involved coupling coefficients. They thus represent practically promising devices for high-resolution-real-time radio.

MA12 EMTheory: Electromagnetic theory and numerical techniques

Antennas/Multi Applications
Room: João G Zarco (Pav 3C)
Chairs: Yahia Antar (Royal Military College of Canada, Canada), Michael J Havrilla (Air Force Institute of Technology, USA)
16:50 Multilevel Fast Multipole Algorithm with Multiple Octrees for the Solution of Large-Scale Plasmonic Problems with Junctions
Hipólito Gómez-Sousa (Northeastern University, USA); Oscar Rubiños-López (University of Vigo, Spain); Jose Martinez Lorenzo (Northeastern University, USA)
This paper presents an implementation of the multilevel fast multipole method (MLFMA), which is used to solve large scattering problems formulated in terms of surface integral equations (SIE). The method is capable of handling multiple composite scatterers with multiple material junctions. Each scatterer defines an electromagnetic region in which a customized octree is created. In particular, for a fixed block size in each octree, the number of levels is always minimized; and, therefore, the number of operations in terms of interpolations, anterpolations and translations is minimized. Furthermore, Kirchhoff's law, relating the current flow across a junction edge, is imposed to ensure high accuracy on the electric field calculation. As a practical application example, the MLFMA with multiple octrees is discussed in this paper in order to design a composite dielectric substrate, which ultimately enhances the directivity of a plasmonic nanoantenna.
17:10 A Four-Vector Formalism for Anisotropic Media
Michael J Havrilla (Air Force Institute of Technology, USA)
An electromagnetic four-vector formalism for anisotropic media is presented and compared to the six-vector formalism. It is shown that, if the material property tensors have a certain form, the four-vector approach significantly reduces mathematical complexity and enhances physical insight due to the more compact formulation and reduced dimensionality. The Green's function for an electric current immersed in a uniaxial media is presented to show the effectiveness of the four-vector formalism and thus demonstrate its usefulness in the radiation and scattering analysis of antennas embedded in complex media environments.
17:30 Diffraction of a Plane Wave by a Rectangular Hole in a Thick Conducting Screen
Hirohide Serizawa (National Institute of Technology, Numazu College, Japan)
The method of the Kobayashi potential (KP) is applied to evaluate an electromagnetic field diffracted by a rectangular hole in an infinite conducting screen with a finite thickness. Since the KP method yields an eigenfunction expansion of the present geometry, the solution satisfies the proper edge condition and we obtain a highly accurate and fast convergent result. Numerical results are obtained for various physical quantities, such as the transmission coefficient, magnitudes of waveguide modes excited in the hole, and aperture field distributions, as well as the far-field patterns. The results of the transmission coefficient and waveguide modes are presented as functions of the thickness to illustrate the effects of the screen thickness on the transmission property.
17:50 On Electromagnetic Radiation in Nonlocal Environments—Steps Toward a Theory of Near Field Engineering
Said Mikki (University of New Haven, USA); Yahia Antar (Royal Military College of Canada, Canada)
We study the antenna radiation field when the surrounding medium is spatially responsive. The Greens function of such nonlocal or spatially dispersive media is derived and a spectral expansion is obtained. It is shown that the antenna can launch both backward and forward wave modes into the far zone, and that this occurs also in a natural way in the near zone. We also demonstrate that the medium can localize the field around the antenna, giving rise to a wide range of potentials for future near field engineering.
18:10 Ultrawideband Inverse Scattering Method for Resonance Region Target Recognition: Application to Small-Scale Airplane Targets with Measured Data
Mustafa Secmen (Yasar University, Turkey)
This paper develops an inverse scattering method to determine the characteristics of resonance region targets by using ultrawideband scattering signals. The method mainly uses multiple time-domain signals for each target, and they are processed to give feature vectors in frequency domain. These vectors contain target-specific information related with characteristics (dimensions of substructures, material properties, etc.) of the known targets. The target recognition is employed by using test (unknown) target's scattering signal. This time-domain signal is processed in an inverse way to get a frequency-domain test vector. Then, the characteristics of test target are assigned as these of one of the known targets with a basic template-matching approach between test vector and feature vectors of these targets. The method is demonstrated for three realistic small-scale airplane. For an ultrawideband system of 0.7-18 GHz, more than 85 percent accuracy has been obtained even under moderate signal-to-noise (SNR) ratio of about 10 dB.

Wednesday, April 15

Wednesday, April 15 9:00 - 12:50 (Europe/Berlin)

C1 VISTA: [C] 2011-2015 early stage research in COST VISTA

Antennas/Multi Applications
Room: Gil Eanes (Aud 3)
Chairs: Nuno Pires (Geosatis SA & Instituto de Telecomunicações/Instituto Superior Técnico, Switzerland), Oscar Quevedo-Teruel (KTH Royal Institute of Technology, Sweden)
9:00 Versatile Measurement System for Imaging Setups Prototyping
Ana Arboleya (Universidad Rey Juan Carlos, Spain); Jaime Laviada, Yuri Álvarez and Cebrián García (Universidad de Oviedo, Spain); Fernando Las-Heras (University of Oviedo, Spain)
An XYZ scanner and its potential capabilities for different types of electromagnetic imaging setups is described in this contribution. To illustrate the operation of the system, two different imaging techniques and setups are presented as examples. A phaseless measurement setup implemented at the Ku band, and a measurement setup based on amplitude and phase acquisitions for the W band.
9:20 Lens-based Ka-band Antenna System Using Planar Feed
Joana Silva (Huber+Suhner, Switzerland); María García-Vigueras (IETR-INSA Rennes, France); Marc Esquius Morote (Ecole Polytechnique Fédérale de Lausanne, Switzerland); Jorge R. Costa (Instituto de Telecomunicações / ISCTE-IUL, Portugal); Carlos A. Fernandes (Instituto de Telecomunicacoes, Instituto Superior Tecnico, Portugal); Juan R Mosig (Ecole Polytechnique Federale de Lausanne, Switzerland)
This paper presents a simple, low-cost and compact mobile ground terminal antenna for Ka-band satellite communications that operates in the downlink band (19.7-20.2 GHz). The antenna is composed by a shaped dielectric lens which tilts in front of a planar feed to direct the beam. The planar feed is a circularly polarized patch antenna placed inside a cavity. The lens allows a mechanical beam steering from 0° to 57° in relation to zenith with a scan loss of 4.5 dB. In order to show the potential of a planar antenna as a feeder for this application, the proposed system is compared with a previous solution composed by the same dielectric lens and a horn antenna as feeder.
9:40 Altering Antenna Radiation Properties with Transformation Optics
Rhiannon C Mitchell-Thomas (University of Exeter, United Kingdom (Great Britain)); Mahsa Ebrahimpouri and Oscar Quevedo-Teruel (KTH Royal Institute of Technology, Sweden)
In this paper, the technique of quasi-conformal transformation optics is utilized to design lenses that can alter the radiation properties of common antennas. The performance of these lenses is simulated using numerical software and analysis shows that the directivity can be increased significantly, or the radiation patterns can be changed as desired. Therefore, using this technique, bespoke lenses can be designed that create complex radiation from simple antenna feed types, for a number of high-frequency applications.
10:00 Pseudo Localization Principle for RFID-Based Smart Blood Stock System
Andela Zaric (IT/IST - University of Lisbon, Portugal); Catarina Cruz (Instituto de Telecomunicações & Instituto Universitário de Lisboa ISCTE-IUL, Portugal); Antonio Matos and Marta Silva (ISCTE-IUL, Portugal); Jorge R. Costa (Instituto de Telecomunicações / ISCTE-IUL, Portugal); Carlos A. Fernandes (Instituto de Telecomunicacoes, Instituto Superior Tecnico, Portugal)
Pseudo localization principle is applied to a RFID-based Smart Blood Stock System in order to automatize and improve the blood management in hospitals and other storage units. The principle is based on using redundant tags both on the blood bags and on the drawer surface to identify and localize each blood bag inside the cabinet and inside the drawer. A prototype system is described and its performance is demonstrated.
10:20 UHF W-BAN Antennas Operating in Indoor and Outdoor Environment
Jovanche Trajkovikj (EPFL, Switzerland); Tomislav Debogovic (SWISSto12 SA, Switzerland); Anja K. Skrivervik (EPFL, Switzerland)
This work presents the performance of wearable PIFA antennas when operating in a real environment conditions, both indoor and outdoor. The proposed PIFA antennas are built out of flexible conductive sheets encapsulated inside a silicone based elastomer, Polydimethylsiloxane (PDMS). A comparison of the PIFA antennas and commercially available wearable flexible dipole antennas is done. The comparison is performed through the set of measurements done with the conventional measurement instruments in the identical indoor/outdoor circumstances. The measurements are performed inside the laboratory corridor, inside the campus buildings, outdoor within the university campus and outdoor in the field (long distance communication). An additional outdoor rotating scenario is made in order to show the importance of the antenna directivity when operating in a real environment. In all the measured cases, PIFA antennas have provided 2-3 dB higher received power compared to the dipoles for the same transmitted power.
10:40 Coffee Break
11:10 Reconfigurable Beams From Millimetre-Wave Leaky-Wave Antennas
Marina Mavridou, Konstantinos Konstantinidis, Alexandros Feresidis and Peter Gardner (University of Birmingham, United Kingdom (Great Britain))
A novel technique for continuous electro-mechanical beam steering is proposed based on Fabry-Perot Leaky-Wave Antennas (LWA). The proposed structure is formed by a Partially Reflective Surface (PRS) placed on top of an Artificial Magnetic Conductor (AMC) ground plane. The reconfiguration is achieved by means of piezoelectric actuators that tune the reflection phase response of the AMC, controlling thus the pointing angle of the antenna's radiation beam for a fixed frequency. The actuators are placed below the ground plane, producing a change in the cavity distance between the ground and the AMC array. The antenna is designed to operate at around 55GHz. Full-wave simulations have been carried out in 3D electromagnetic simulation software (CST Microwave StudioTM) demonstrating beam configuration with continuous scanning from 15o to 50o.
11:30 Synthesis Procedure for Thinned Leaky-Wave Phased Array Antennas
Francesco Scattone (Microwave Vision Group (MVG), Italy); Mauro Ettorre (University of Rennes 1 & UMR CNRS 6164, France); Benjamin Fuchs (University of Rennes 1 - IETR, France); Ronan Sauleau (University of Rennes 1, France); Nelson Fonseca (European Space Agency, The Netherlands)
In this work we propose a synthesis method to design thinned leaky-wave-based phased arrays. The radiators are apertures on a ground plane in a superstrate configuration. A leaky-wave mode is excited by the radiating apertures between the ground plane and the superstrate. A convex l1 optimization procedure is used to reduce the number of elements of the array, keeping the radiation pattern within a predefined mask. The mutual coupling among the elements in the superstrate configuration is taken into account during the optimization procedure. The final results provide array structures with a reduced number of elements and an enhanced aperture efficiency with respect to the configuration without superstrate.
11:50 Insightful Circuit Modeling of FSS with Arbitrary Scatterers
María García-Vigueras (IETR-INSA Rennes, France); Francisco Mesa (University of Seville, Spain); Raúl Rodríguez-Berral (Universidad de Sevilla, Spain); Francisco Medina (University of Sevilla, Spain); Juan R Mosig (Ecole Polytechnique Federale de Lausanne, Switzerland)
A physical insightful and quasi-analytical circuit model is here proposed in order to characterize frequency selective surfaces composed by scatterers/apertures of arbitrary geometry. The present work is an extension of the approach previously proposed by some of the authors that dealt only with simple dipole-based periodic surfaces. In order to account for scatterers of more complex shape, their current profile is extracted from a full-wave tool at a single frequency. Our numerical results are validated through comparison with commercial simulators as well as with previously proposed circuit-model approaches.
12:10 Magnetic Nanoparticles Enhanced Breast Cancer Microwave Imaging Via Compressive Sensing
Martina Teresa Bevacqua (Università Mediterranea di Reggio Calabria, Italy); Rosa Scapaticci (CNR-National Research Council of Italy, Italy)
Magnetic nanoparticles have been recently proposed as contrast agent in microwave breast cancer imaging. As a matter of fact, being human tissues non-magnetic, their use would allow achieving a reliable and specific diagnosis of breast cancer, by pursuing the reconstruction of a magnetic contrast into a totally electric scenario. In this communication, we investigate the adoption of compressive sensing as imaging strategy, which has been recently considered to solve linear problems in which the unknown is sparse. In this respect, the low amount of nanoparticles actually targetable assures that the problem to be faced in MNP enhance MWI is linear. In addition, being the magnetic contrast associated to the targeted tumour small and localized, the sought unknown function is also intrinsically sparse.
12:30 Evolution of Pin-Flange Adapters for High Frequency Measurements
Sofia Rahiminejad (Chalmers University of Technology, Sweden); Elena Pucci (Ericsson AB, Sweden); Sjoerd Haasl (Royal Institute of Technology, Sweden); Peter Enoksson (Chalmers University of Technology, Sweden)
Measurements with waveguide flanges at high frequencies have a considerable issue with leakage due to problems with achieving good electrical contact between the opposite flange parts. The higher the frequency, the lower the tolerance is to gaps. However, by using gap waveguide technology in the form of a pin flange adapter between the two flange parts, measurements can be performed without requiring electric contact to the flange of the measurement object. This paper describes the development of the pin-flange adapter from simulation to the latest polymer version.

C15 Prop5G: [C] Channel measurements and modelling in the higher frequency bands for 5G

Propagation/Cellular Communications
Room: Pêro Escobar (Pav 3A)
Chairs: Thomas Kuerner (Braunschweig Technical University, Germany), Sana Salous (Durham University, United Kingdom (Great Britain))
9:00 Large Scale Characteristics of Urban Cellular Wideband Channels At 11 GHz
Minseok Kim (Niigata University, Japan); Jun-ichi Takada and Yuyuan Chang (Tokyo Institute of Technology, Japan); Jiyun Shen (NTT DOCOMO, INC., Japan); Yasuhiro Oda (NTT DoCoMo, Japan)
High frequency spectrum is expected to offer a wide bandwidth for future broadband cellular networks. This paper presents the measurement results of the outdoor urban cellular wideband channels at $11$ GHz. The measurements at various urban cellular environments that are classified into macrocell, microcell and street-cell were conducted. A wideband 24x24 MIMO channel sounder having 400 MHz signal bandwidth and dual-polarized 12-element uniform circular arrays were used. This paper presents the large scale characteristics including path losses, shadowing, cell coverage, polarization properties and delay spread, which were calculated by the polarimetric beamforming both at transmitter and receiver. Large shadowing loss of approximately 20 dB was observed in NLoS condition, and from the outage calculation it was seen that the cell coverage is limited to less than 100 m for 30 dB SNR. In addition, Small RMS delay spreads with the mean value of less than 20 ns were observed.
9:20 Phase Noise Effects on the Precision of Wideband Mobile Radio Channel Sounding Methods
Carlos E Salles Ferreira (Universidade Federal Fluminense, Brazil); Gláucio Lima Siqueira (Pontifícia Universidade Católica do Rio de Janeiro, Brazil); Raimundo Sampaio-Neto (Cetuc-Puc-Rio, Brazil)
In this work three wideband mobile radio channel sounding methods are simulated and compared using computational tools. The sounders are based on OFDM, Matched Filter and STDCC methods, and different values for the level of the phase noise introduced by the receiver local oscillator are compared. The impact of this oscillator imperfection is analyzed by comparing the estimated channel results with the simulated reference channel. Other impairments factors like thermal noise or nonlinear distortion affecting the system are not considered..
9:40 Vectorial Channel Sounding of MISO Propagation Channels Without Synchronization
Georg Zimmer (Technische Universität Braunschweig, Germany); Robert Geise (Technische Universität Braunschweig & University of Applied Science for Telecommunication Engineering Leipzig, Germany); Björn Neubauer (Technische Universität Braunschweig, Germany)
A vectorial channel sounder with multiple transmitting antennas and one receiving antenna is presented. It characterizes time variant propagation channels providing a measure of how wave propagation deviates from ideal free space propagation. In particular, it quantifies amplitude modulation characteristics in a multipath environment as well as a frequency modulation due to moving scatterers in the propagation path. Moreover, this vectorial channel sounder distinguishes properties of a propagation that depend on emitting antennas with different characteristics, such as polarization, location and emitting directions. This paper focusses on coding and detection algorithms of individual timing schemes applied to emitting antennas allowing a vectorial channel sounding without any synchronization. A reduction of the required sample rate is achieved by downconversion of the channel RF to an intermediate frequency. A typical application is the measurement of narrowband multipath propagation channels of navigation systems, e.g. a multipath environment with a miniaturized rotating wind turbine.
10:00 Review of Millimeter-wave Propagation Characterization and Modelling Towards 5G Systems
Sana Salous (Durham University, United Kingdom (Great Britain)); Maziar Nekovee (Samsung Electronics, United Kingdom (Great Britain)); Vittorio Degli-Esposti (University of Bologna, Italy); Sooyoung Hur (Samsung Electronics Co., Korea (South))
The paper discusses the various propagation and modelling issues surrounding the use of mm Waves in future wireless systems. State of the art radio channel sounders are presented and desirable channel measurements to identify the multipath components are identified. Challenges of radio propagation measurements in such frequency bands are highlighted. Current and future standardization issues are outlined with recommendations for future research.
10:20 Simultaneous Millimeter-Wave Multi-Band Channel Sounding in an Urban Access Scenario
Richard J. Weiler (Fraunhofer HHI, Germany); Michael Peter (Fraunhofer Institute for Telecommunications, Heinrich Hertz Institute, Germany); Thomas Kühne (Technische Universität Berlin, Germany); Mike Wisotzki and Wilhelm Keusgen (Fraunhofer Heinrich Hertz Institute, Germany)
The frequency bands above 6 GHz up to millimeter-waves are a promising candidate to mitigate the scarcity of available spectrum in future mobile radio network deployments. The knowledge of the radio channel in these bands and a comprehensive channel model is vital for the design of such future systems. In this paper we present channel measurements that have been simultaneously performed at 10 GHz and 60 GHz in an urban access scenario. These measurement results could serve as a starting point for the development of a frequency independent above 6 GHz channel model.
10:40 Coffee Break
11:10 Polarimetric Analysis of Mm-Wave Propagation for Advanced Beamforming Applications
Vittorio Degli-Esposti, Franco Fuschini, Enrico M. Vitucci and Marina Barbiroli (University of Bologna, Italy); Marco Zoli (Barkhausen Institut gGmbH, Germany); Diego Dupleich (Ilmenau University of Technology, Germany); Robert Müller (TU Ilmenau, Germany); Christian Schneider and Reiner S. Thomä (Ilmenau University of Technology, Germany)
Pencil-beam forming techniques based on large antenna arrays is becoming a crucial asset to cope with the very high throughput density requirements and high path-loss of future millimeter-wave gigabit-wireless applications. 60 GHz directional, polarimetric indoor measurements are used in the present work to modify and calibrate a 3D ray tracing model and in particular to tune the embedded effective-roughness diffuse scattering model. The potential of polarimetric beamforming is then evaluated through system simulation in simple, reference cases using the 3D ray tracing model as a propagation-prediction engine.
11:30 28 GHz Indoor Channel Measurements and Modelling in Laboratory Environment Using Directional Antennas
Xianyue Wu (Heriot-Watt University, United Kingdom (Great Britain)); Yan Zhang (Beijing Institute of Technology, China); Cheng-Xiang Wang (Southeast University & Heriot-Watt University, China); George Goussetis (Heriot-Watt University, United Kingdom (Great Britain)); el-Hadi M. Aggoune (University of Tabuk & Director of Sensor Networks and Cellular System (SNCS) Research Center, Saudi Arabia); Mohammed Alwakeel (University of Tabuk, Saudi Arabia)
The millimeter-wave band will be one of the key components for the fifth generation (5G) wireless communication systems. A radio channel measurement was conducted at 28 GHz in a laboratory environment. Two horn antennas were used with a vector network analyzer. The transmitter antenna was fixed in one direction while the receiver antenna was rotated 360 degrees in azimuth in the measurement. The space-alternating generalized expectation maximization algorithm was utilized for the rotated directional antenna scenario to estimate channel parameters of multipath components. Power delay profile, power angle profile and root mean square delay spread were obtained from the measured results. The Saleh-Valenzuela model was used to characterize the measured channel and the intra-cluster parameters were extracted.
11:50 Wideband Spatial Channel Model in an Urban Cellular Environments At 28 GHz
Sooyoung Hur (Samsung Electronics Co., Korea (South)); Yeon-Jea Cho and Taehwan Kim (KAIST, Korea (South)); Jeongho Park (Samsung Electronics, Korea (South)); Andreas Molisch (University of Southern California, USA); Katsuyuki Haneda (Aalto University, Finland); Michael Peter (Fraunhofer Institute for Telecommunications, Heinrich Hertz Institute, Germany)
This paper presents channel propagation measurements and analysis to investigate the channel characteristics of millimeter wave (mmWave) transmission for urban cellular communication systems, in particular at the promising frequency 28 GHz band. For channel propagation analysis, the urban measurement campaign was conducted with a synchronously spherical scanning 28 GHz channel sounder system, then omni-like channel measurements are obtained for channel modeling work. From the measurements, we analyze the spatio-temporal channel characteristics such as multipath delay, angular statistics, and pathloss. The clustering analysis has been done including its power distribution. Then, a set of millimeter wave radio propagation parameters are presented, and the corresponding channel models based on the spatial channel model (SCM) are also described. This paper propose the initial channel model to construct the channel propagation models based on urban measurement campaign in millimeter wave 28 GHz band.
12:10 On Path Loss Measurement and Modeling for Millimeter-wave 5G
Michael Peter (Fraunhofer Institute for Telecommunications, Heinrich Hertz Institute, Germany); Wilhelm Keusgen (Fraunhofer Heinrich Hertz Institute, Germany); Richard J. Weiler (Fraunhofer HHI, Germany)
This paper addresses the derivation of path loss models and appropriate model parameters based on measurement data, in particular with a view to current modeling work for 5G millimeter-wave systems. In order to ensure reliable and comparable results, which are independent from the measurement hardware, it is of utmost importance to incorporate a sufficiently large data set and use a coherent data processing including spatial averaging.

Wednesday, April 15 9:00 - 10:40 (Europe/Berlin)

C20 RadioC: [C] Dynamic radio channel modelling in mobile-to-mobile heterogeneous networks

Propagation/Wireless Networks
Room: Afonso de Albuquerque (Pav 3B)
Chairs: Raffaele D'Errico (CEA, LETI, Minatec Campus & Univ\. Grenoble-Alpes, France), Claude Oestges (Université Catholique de Louvain, Belgium)
9:00 Doppler Analysis of an Indoor University-Hall
Brecht Hanssens, Emmeric Tanghe and Luc Martens (Ghent University, Belgium); Claude Oestges (Université Catholique de Louvain, Belgium); Wout Joseph (Ghent University/IMEC, Belgium)
An analysis of delay-Doppler characteristics in the presence of moving people is presented for short-range communications in an indoor environment. Channel sounding measurements have been carried out at 3.6 GHz in a crowded university-hall during short and long breaks between courses. The measurements reveal a difference between the RMS Doppler spread of both breaks, indicating a distinctive power distribution of their Doppler spectra. In addition, there is a significant contrast between the Doppler characteristics of the co- and cross-polarizations. Looking at the behavior of both the Doppler- and RMS Doppler spread, we also highlight the importance of characterizing multipaths in the environment.
9:20 Channel Measurements of Device-to-Device Communications At 2.45 GHz
Simon Cotton (Queen's University, Belfast, United Kingdom (Great Britain)); Nidhi Bhargav (Queen's University Belfast, United Kingdom (Great Britain))
In the future, device-to-device communications will become a fundamental part of cellular communications. Interoperability between handsets will be facilitated using frequencies located in a number of bands including those found in the Industrial, Scientific and Medical (ISM) band at 2.45 GHz. In this paper, we present the results of channel measurements made between two hypothetical cellular handsets operating at 2.45 GHz in an outdoor environment. We consider a range of typical usage scenarios such as both user equipment being held at the head while imitating a voice call, placed in user's pocket for both stationary and dynamic links. A range of parameter estimates obtained using the shadowed κ–μ fading model are also presented.
9:40 A Non-Stationary Mobile-to-Mobile Multipath Fading Channel Model Taking Account of Velocity Variations of the Mobile Stations
Wiem Dahech (Ecole Superieure des Communications de Tunis, Sup'com, Tunisia); Matthias Pätzold (University of Agder, Norway); Neji Youssef (Ecole superieure des communications de Tunis, Tunisia)
In mobile-to-mobile (M2M) communication systems, both the transmitter and the receiver mobile stations are moving with a certain velocity which is usually assumed to be constant over time. However, in realistic propagation scenarios, the mobile velocity changes continuously resulting in a non-stationary fading process. In this paper, we focus on the analysis of a non-stationary M2M multipath fading channel model, where the transmitter and the receiver may experience changes in their velocities. For the proposed model, we derive expressions for the local autocorrelation function (ACF) and the local power spectral density (PSD). By relaxing the assumption of constant velocity, our study shows that the correlation properties of the M2M fading channel are significantly affected.
10:00 Modeling Impact of Moving Scatterers on Doppler Spectrum in Vehicle-to-Vehicle Channels
Alenka Zajic (Georgia Institute of Technology, USA)
A three-dimensional (3-D) geometrical propagation model that includes both stationary and moving scatterers around the transmitter and receiver for wideband multiple-input multiple-output (MIMO) vehicle-to-vehicle (V-to-V) communications is proposed. The modeled Doppler spectrum agrees well with the empirically obtained Doppler spectrum and shows the importance of including moving scatterers into propagation models.
10:20 Geometry-Based Path Interpolation for Rapid Ray-Optical Modeling of Vehicular Channels
Jörg Nuckelt and Thomas Kürner (Technische Universität Braunschweig, Germany); Moritz Schack (TU Braunschweig, Germany)
Ray-optical algorithms are an excellent choice to model the radio channel in a deterministic manner. Especially, in vehicular environments where the channel is time-variant and system designer potentially need to consider the non-stationarity of the channel, ray-tracing tools are a welcome solution to evaluate the achievable system performance in specific scenarios. The main drawback of ray-optical models is the high complexity resulting in time consuming simulations - especially when a high time resolution of the channel is required and the considered scenario is complex. In this paper, we present an approach to reduce the utilization rate of ray-optical models. A geometry-based interpolation algorithm is employed to efficiently obtain information about the propagation paths between two consecutive scenario snapshots. The presented approach has been verified against high-resolution results of a ray-optical channel model.

Wednesday, April 15 9:00 - 12:50 (Europe/Berlin)


Antennas/Bridging other Areas
Room: Diogo Cão (Aud 8)
Chairs: Lale Alatan (METU, Turkey), Juan R Mosig (Ecole Polytechnique Federale de Lausanne, Switzerland)
9:00 The SIE-MoM Analysis of Dielectric Bodies Embedded in a Shielded Stratified Medium
Bartosz Bieda, Robert Borowiec and Andrzej A. Kucharski (Wroclaw University of Technology, Poland); Piotr Słobodzian (Wroclaw University of Technology & Faculty of Electronics, Poland)
This paper describes formulation and application of the surface integral equation (SIE) approach to the problem of scattering by material bodies inside waveguides and cavities filled with a stratified medium. The formulation in based on the full dyadic electric and magnetic waveguide Green functions both for the external and internal equivalent problems. To the best authors knowledge such an approach has never been presented in the open literature. In this paper we show numerical and experimental validation of the proposed formulation and a comparison of its performance with the Finite Integration Technique (FIT) implemented in commercial software
9:20 A High Order Locally Corrected Nystrom Implementation of the Decoupled Potential Integral Equation
Felipe Vico (Universidad Politécnica de Valencia, Spain); Miguel Ferrando-Bataller (Universitat Politècnica de València, Spain); Tomás Bernabeu-Jiménez (Universitat Politècnica de València & Instituto de Telecomunicaciones y Aplicaciones Multimedia (ITEAM), Spain); Antonio Berenguer (Universitat Politecnica de Valencia & Instituto de Telecomunicaciones y Aplicaciones Multimedia, Spain)
In this paper we present a numerical implementation of the Decoupled Potential Integral Equation DPIE based on a high order locally corrected Nystrom method. The DPIE formulation allows to describe the scattering electromagnetic field by a perfect electric conductor in a decoupled way. The scattered scalar potential $\phi^{\Sc}$ is obtained entirely from the incoming scalar potential $\phi^{\In}$, and the scattered vector potential $\bA^{\Sc}$ is computed from the incoming vector potential $\bA^{\In}$. This formulation is exact for any frequency $\omega\ge 0$. We recover the time harmonic scattered potentials in the Lorenz gauge that allow us to compute the scattered electric and magnetic fields $\bE^{\Sc}, \bH^{\Sc}$.
9:40 Improvements in the MoM Analysis of 3-D Planar Multilayered Periodic Structures Used in the Design of Wideband Reflectarray Antennas
Rafael Florencio (Universidad de Sevilla, Spain); Rafael R. Boix (University of Seville, Spain); Jose A. Encinar (Universidad Politecnica de Madrid, Spain)
The design of reflectarray antennas made of cells with stacked rectangular patches requires to analyze many times the scattering of plane waves by periodic arrays of stacked rectangular patches in multilayered substrates. Since the application of the Method of Moments (MoM) in the spectral domain to this problem leads to the determination of slowly convergent double infinite summations, in this paper we present a hybrid spectral domain-spatial domain approach where these summations are transformed into singular finite double integrals. The multilayered periodic Green's functions involved in these double integrals are interpolated in terms of 2-D Chebyshev polynomials. Also, Ma-Rokhlin-Wandzura quadrature rules are used to handle the logarithmic singularities of the double integrals. Thanks to these two strategies, the novel hybrid MoM approach turns out to be between one and two orders of magnitude faster than the standard spectral domain MoM approach for an accuracy of two significant figures.
10:00 Power Computations in VIE Formulations
Athanasios Polimeridis (Skolkovo Institute of Science and Technology, Russia); M. T. Homer Reid (MIT, USA); Steven G. Johnson and Jacob White (Massachusetts Institute of Technology, USA); Alejandro Rodriguez (Princeton University, USA)
We report a collection of simple and stable formulas for computing power (including absorbed/radiated, scattered and extinction power) in current-based volume integral equation formulations. The proposed formulas are given in terms of vector-matrix-vector products of quantities found solely in the associated linear system.
10:20 Hierarchical Bases Preconditioners for a Conformingly Discretized Combined Field Integral Equation Operator
Simon B Adrian (Technische Universität München & Institut Mines-Télécom / Télécom Bretagne, Germany); Francesco Andriulli (Ecole Nationale Superieure des Telecomunications de Bretagne, France); Thomas F. Eibert (Technical University of Munich (TUM) & Chair of High-Frequency Engineering (HFT), Germany)
In this work, we show how hierarchical bases preconditioners constructed for stabilizing the electric field integral equation (EFIE) operator can be used for stabilizing the combined field integral equation (CFIE) operator. Since the CFIE operator consists of the EFIE and magnetic field integral equation (MFIE) operator, also the CFIE operator is affect by the low-frequency and the dense-discretization breakdown of the EFIE operator. We show that the hierarchical basis preconditioner for the EFIE operator must not directly be applied to the CFIE operator, since this would introduce a new ill-conditioning. Instead, Helmholtz projectors are used in a left-preconditioning scheme for implicitly regularizing the solenoidal Helmholtz subspace of the CFIE operator, while the hierarchical stars are used for the regularization of the non-solenoidal Helmholtz subspace. Numerical results corroborate the presented theory.
10:40 Coffee Break
11:10 Volumetric Testing for the Nonconforming Discretization of Integral Equations in Scattering Problems
Eduard Ubeda and Ivan Sekulic (Universitat Politècnica de Catalunya (UPC), Spain); Juan M. Rius (Universitat Politècnica de Catalunya, Spain); Alexander Heldring (Polytechnical University of Catalunya, Spain)
Traditional discretizations of the electric-field integral equation (EFIE) impose the continuity of the normal component current across the edges in the meshing. These edge-oriented schemes become awkward in the analysis of composite objects or of closed conductors meshed with nonconformal meshes. In this context, the nonconforming expansion of the current with facet-oriented schemes, like the monopolar-RWG set, with no imposed interelement continuity, leads to EFIE-implementations with enhanced versatility. However, the traditional Galerkin method-of-moment implementation gives rise to hypersingular Kernel contributions, which cannot be evaluated numerically. Recently, we have proposed a nonconforming monopolar-RWG discretization of the EFIE where the testing is carried out over volumetric elements attached to the surface triangulation inside the object under analysis. In this paper, we review the so-called volumetric monopolar-RWG discretization of the EFIE with testing over tetrahedral or wedge elements and show the observed improved accuracy in the scattering analysis when compared with the RWG-discretization.
11:30 MLFMA for Large-Scale Nanoplasmonics Modeling
Diego M. Solís (University of Vigo, Spain); Jose M. Taboada (University of Extremadura, Spain); Fernando Obelleiro (University of Vigo, Spain); F. Javier García de Abajo (ICFO (The Institute of Photonic Sciences), Spain); Luis M. Liz-Marzán (CIC BIOMAGUNE, Spain)
The advance in nanoplasmonics is oftentimes limited by the availability of electromagnetic analysis tools capable of addressing large, complex realistic systems that encompass multiple wavelength scales. The present work shows that surface integral equation (SIE) method of moments (MoM) formulations, expedited via the multilevel fast multipole algorithm (MLFMA), can effectively model the interaction of light with large nanoplasmonic assemblies. We illustrate this by simulating realistic gold-nanostar dimers and analyzing the application of their plasmons for sensing, thanks to spatial confinement and field enhancement. We further simulate surface-enhanced Raman scattering (SERS) intensity maps from a thin film containing ∼1500 of these nanostars. The proposed methodology raises the bar of full-wave simulations in the field of nanoplasmonics to an unprecedented level of complexity.
11:50 Fully Numerical Evaluation of 4-D Reaction Integrals in the Method of Moments
Donald Wilton (University of Houston, USA); Francesca Vipiana (Politecnico di Torino, Italy); William Johnson (Private Consultant, USA)
We present a novel strategy for the fully numerical evaluation of 4-D reaction integrals in the Method of Moments. The proposed scheme is based on applying the divergence theorem to both the source and testing surface integrals, together with appropriate changes in the integration order. The resulting 4-D surface integral is expressed as two radial integrals plus two contour integrals over source and observation domain boundaries. The radial integrals significantly smooth the kernel, and the resulting contour integrals are further regularized for efficient numerical evaluation. Numerical examples will show the accuracy of the proposed numerical integration scheme in the case of singular and near singular kernels that arise in the Electric Field Integral Equation (EFIE) formulation. For simplicity, emphasis is on the case of co-planar source and testing domains.
12:10 An Iterative Solution Approach of the Magnetic Field Integral Equation for Scattering Computations
Robert Brem (Technische Universität München, Germany); Simon B Adrian (Technische Universität München & Institut Mines-Télécom / Télécom Bretagne, Germany); Thomas F. Eibert (Technical University of Munich (TUM) & Chair of High-Frequency Engineering (HFT), Germany)
A simple iterative solution of the magnetic field integral equation (MFIE) for scattering computations at perfect electrically conducting (PEC) objects is investigated. The proposed method uses pulse basis functions and point-matching for integral evaluation together with several concepts as utilized in the iterative physical optics (IPO) approach. Furthermore, a special correction scheme for the stabilization of the solution is introduced and tested. It is found that good approximate solutions can be obtained, which are considerably more accurate than asymptotic solutions and less computer intensive than full wave numerical methods.
12:30 Numerical Solution of Diffraction Problems Using Large Matrix Compression
Gleb Ryzhakov and Alexander Mikhalev (Skolkovo Institute of Science and Technology, Russia); Daria Sushnikova (Institute of Numerical Mathematics of Russian Academy of Sciences, Russia); Ivan Oseledets (Skolkovo Institute of Science and Technology & Institute of Numerical Mathematics of Russian Academy of Sciences, Russia)
We present an application of $\mathcal H^2$-matrix compression to the problem of diffraction of electromagnetic wave on ideal-conductive bodies in the 3D case. Numerical examples are given. In the case, when the body is electrically large, a fine grid on the body is needed to approximate the unknown function with good accuracy. Thus, the matrix dimension of the corresponding system of linear equations is large (about $10^5$ and more) and the system cannot be solved directly due to insufficient of memory.

C33 mmAnt: [C] Mm-wave Antenna Systems

Antennas/High Data-rate Transfer
Room: Gonçalo V Cabral (Pav 5C)
Chairs: Cyril Luxey (University Nice Sophia-Antipolis, France), Marta Martínez-Vázquez (IMST GmbH, Germany)
9:00 Millimeter-Wave Antennas for Radio Access and Backhaul in 5G Heterogeneous Mobile Networks
Laurent Dussopt (CEA, LETI, Minatec, France); Ossama El Bouayadi (CEA, France); Jose Alberto Zevallos Luna (CEA, LETI, Minatec, France); Cedric Dehos (CEA, France); Yann Lamy (CEA, LETI, Minatec, France)
Millimeter-wave communications are expected to play a key role in future 5G mobile networks to overcome the dramatic traffic growth expected over the next decade. Such systems will severely challenge antenna technologies used at mobile terminal, access point or backhaul/fronthaul levels. This paper provides an overview of the authors' recent achievements in the design of integrated antennas, antenna arrays and high-directivity quasi-optical antennas for high data-rate 60-GHz communications.
9:20 Rotman Lens with Ridge-Gap Waveguide, Implemented in LTCC Technology, for 60 GHz Applications
Fernando Carrera-Suárez and Diana Navarro-Méndez (Universidad Politécnica de Valencia & Escuela Politécnica Nacional, Spain); Mariano Baquero-Escudero and Alejandro Valero-Nogueira (Universidad Politécnica de Valencia, Spain)
This paper presents the design and simulations of a Rotman lens for use at 60 GHz frequency band. This lens will be used as a feeding network for a multi-beam antenna. Both the lens and the antenna array will be made in LTCC technology. To avoid the losses produced by the ceramic material used in LTCC, the lens has been designed based in Ridge-Gap Waveguides for the input and output ports. Since wave propagation in ridge-gap waveguides takes place in air, loss is significantly reduced. This is an important advantage when comparing with other common technologies such as microstrip lenses in LTCC.
9:40 Broadband Circularly Polarized Aperture-Coupled Microstrip Antenna in HDI Technology for WiGig Applications
Aimeric Bisognin (University Nice Sophia-Antipolis & STMicroelectronics, France); Diane Titz (University Nice Sophia Antipolis, France); Gilles Jacquemod (University of Nice, France); Romain Pilard (STMicroelectronics, Technology R&D, STD, TPS Lab, France); Frédéric Gianesello and Daniel Gloria (STMicroelectronics, France); Frédéric Devillers (Orange Labs-CREMANT, France); Cyril Luxey (University Nice Sophia-Antipolis, France)
In this paper, we present a single feed cross-slot aperture coupled microstrip patch antenna for WiGig applications. This circularly polarized antenna is integrated in a ball-grid-array organic module designed in a low cost High Density Interconnect technology. The shape of the aperture is carefully optimized in order to achieve a broadband axial ratio. This aperture consists of two orthogoal rectangular slots augmented with circular slots at each end. The packaged antenna has dimensions of 4.6x4.6x0.5 mm3. In the boresight direction, simulation results exhibit a 3dB axial ratio over a 23% relative bandwidth at 60GHz and a realized gain higher than 6dBi from 57GHz to 69GHz.
10:00 Intersymbol Interference Analysis of a 60 GHz-Band Compact Range Wireless Access System
Miao Zhang (Xiamen University, China); Kiyomichi Araki, Jiro Hirokawa and Makoto Ando (Tokyo Institute of Technology, Japan)
A compact range wireless access system in the 60 GHz-band has been proposed for muti-Gb/s data transfer. A prototype Gigabit Access Transponder Equipment was made to evaluate the system performance of bit-error rate (BER) and signal-to-noise ratio. An error-free communication zone up to 11 m is available by adopting the 32×32 and 64×64-element waveguide slot arrays in the transmitter. However, the BER degrades especially for the propagation distance less than 1 m. In this study, the concept of intersymbol interference (ISI) is introduced in the antenna and propagation field for the first time. An equivalent baseband communication system is newly proposed to evaluate the wireless channel including antennas. The ISI as well as BER for the circular aperture antenna is theoretically analyzed as a function of propagation distance.
10:20 On-chip and In-package Antennas for mm-Wave CMOS Circuits
This paper discusses challenges, design issues and possible solutions to get mm-Wave signals off-chip. Simulation- and measurement results are discussed for three mm-Wave designs at different frequencies in bulk CMOS technology. (1) The design of a back-to-back IC-to-board interconnect using wire-bonding and microstrip lines is described to package and measure the chips without the need for a mm-Wave probe. (2) An on-chip antenna implementation at 540GHz in a 40nm CMOS technology with metal reflector is discussed. And (3) an on-chip collinear broadside array at 120GHz, also designed in a 40nm CMOS technology and flip-chipped on an alumina substrate is proposed as a possible solution.
10:40 Coffee Break
11:10 Compact 28 GHz Antenna Array with Full Polarization Flexibility Under Yaw, Pitch, Roll Motions
Wonbin Hong, Kwanghyun Baek, Youngju Lee and Seungtae Ko (Samsung Electronics, Korea (South))
Novel antenna design technologies are devised at 28 GHz to realize vertical and horizontal polarizations and its combined radiation characteristics using ultra-thin printed circuit board (PCB) substrates. Details of the design methodologies, simulation and measurement results are presented and discussed in relation to the targeted mmWave 5G mobile application.
11:30 On-Chip Antenna Integration for Single-Chip Millimeter-Wave FMCW Radars
Bedilu Adela (Eindhoven University of Technology, The Netherlands); Paul Zeijl (Omniradar, The Netherlands); A. B. (Bart) Smolders (Eindhoven University of Technology, The Netherlands)
On-chip antennas for single-chip millimeter-wave radar have been designed. The chip is configured to have one transmitting and two receiving antennas of which the performance (matching, gain and surface wave suppression) was optimized during the design process, including the PCB packaging substrate. Simulation results show that the on-chip antenna integrated on 200 micro-meter thick, 20 Ohm-cm silicon and placed on an optimized PCB environment has more than 30% impedance bandwidth. The concept suppresses surface waves, resulting in a relative high gain of 5 dBi with an overall efficiency of 33%. Furthermore, it meets the specific FMCW-radar requirements such as high isolation (more than 25 dB) between transmitting and receiving antennas and a ripple-free broadside radiation pattern.
11:50 Compact Terahertz Instruments for Planetary Missions
Goutam Chattopadhyay (NASA-JPL/Caltech, USA); Theodore Reck, Adrian Tang and Cecile Jung-Kubiak (NASA-JPL, Caltech, USA); Choonsup Lee (JPL, USA); Jose V Siles (NASA Jet Propulsion Laboratory, USA); Erich Schlecht (NASA-JPL, Caltech, USA); Yanghyo Kim and M-c Chang (UCLA, USA); Imran Mehdi (JPL, USA)
Using newly developed silicon micromachining technology that enables low-mass and highly integrated receivers, we are developing a state-of-the-art terahertz radiometer/spectrometer instrument for planetary orbiter missions to Mars, Venus, Titan, and the Galilean moons. Our flexible receiver architecture provides a powerful instrument capability in a light-weight, low-power consuming compact package which offer unprecedented sensitivity performance, spectral coverage, and scalability to meet the scientific requirements of multiple missions.
12:10 A Lens-Coupled All-Silicon Integrated 2x2 Array of Harmonic Receivers for THz Multi-Color Active Imaging
Janusz Grzyb, Konstantin Statnikov and Ullrich Pfeiffer (University of Wuppertal, Germany)
This abstract reports on an innovative lens-coupled 2x2 array of broadband on-chip antenna integrated harmonic receivers in 0.25µm SiGe BiCMOS technology for multi-color imaging in the 0.16-1THz frequency band. Multiple antenna-circuit co-design aspects will be studied resulting in the receiver performance appropriately equalized for ultra wideband operation under simultaneous illumination by multiple harmonic signals across a frequency range of interest.
12:30 Gain Enhancement of Low Profile On-Chip Dipole Antenna Via Artificial Magnetic Conductor At 94 GHz
Mahmoud Nafe (King Abdullah University for Science and Technology, Saudi Arabia); Atif Shamim (King Abdullah University of Science and Technology, Saudi Arabia); Ahad Syed (King Abdullah University for Science and Technology, Saudi Arabia)
The bottleneck for realizing high efficiency System-on-Chip is integrating the antenna on the lossy silicon substrate. To shield the antenna from the silicon, a ground plane can be used. However, the ultra-thin oxide does not provide enough separation between the antenna and the ground plane. In this work, we demonstrate one of the highest reported gains to date for low profile 94 GHz on-chip dipole antenna while the ground plane is in the lowest metal in the oxide (M1). This is achieved by optimizing an Artificial Magnetic Conductor (AMC) structure midway the antenna and M1. The dipole antenna without the AMC has a gain of – 11 dBi while with the AMC structure a gain of + 4.8 dBi and hence achieving a gain enhancement of + 15.8 dBi

C44 MiMed2: [C] Therapeutic Applications of Electromagnetic Fields (MiMed)

Room: Pedro A Cabral (Aud 2)
Chairs: Margarethus M. Paulides (Eindhoven University of Technology, The Netherlands), Desmond Teck Beng Yeo (GE Global Research, USA)
9:00 Focusing and Steering for Medical Applications with Magnetic Near-Field Arrays and Metasurfaces
Alon Ludwig (MathWorks, USA); Joseph Wong (University of Toronto, Canada); Ariel Epstein (Technion - Israel Institute of Technology, Israel); George V. Eleftheriades and Costas D Sarris (University of Toronto, Canada)
Two recently suggested 2D structures for control of electromagnetic beams are presented; the magnetic near-field antenna array and the Huygens metasurface. Opportunities and challenges in the context of medical applications are discussed.
9:20 Optimization of Chest Wall Hyperthermia Treatment Using a Virtual Human Chest Model
Dario Rodrigues (University of Maryland School of Medicine, USA); Mark Hurwitz (Thomas Jefferson University, USA); Paolo Maccarini (Duke University); Paul Stauffer (Thomas Jefferson University, USA)
This work explores different coupling configurations (direct contact, air and water coupling) between a single 915 MHz waveguide applicator and human tissue in the setting of chest wall recurrence (CWR) of breast cancer. The objective is to treat chest wall tumours with microwave hyperthermia, while avoiding hot spots in critical areas such as scars and ribs. The best coupling configuration was a customized 24×29 cm water bolus developed by our team. It helps the applicator deliver an effective field size of 268 cm2 at 1 cm depth and a penetration depth of 2-3 cm. Water bolus thickness can be adjusted during treatment (0.5-4 cm) to shift hot spot locations and thus homogenize thermal dose delivered over a 60 min hyperthermia treatment. The virtual human chest model is easily customized so it can be used as a tool for treatment planning and quality assurance testing of microwave applicator configurations.
9:40 Design and Characterization of on-Head Antenna Systems for Neural Motor Prosthesis
Terence S.P. See and Xianming Qing (Institute for Infocomm Research, Singapore); Zhi Ning Chen (National University of Singapore, Singapore)
This paper presents two antennas at 434 MHz for neuro motor prosthesis. The implanted antenna consists of a meandered dipole that can be positioned on the head. The external antenna is a high permittivity periodic structure loaded planar dipole antenna which is of low profile and has high directivity. Both the antennas are optimized with the head tissues that are approximated by three homogeneous layers consisting of skin, fat, and muscle. The antenna system exhibits a link loss of about 14 dB when the antennas are placed 8 cm away from each other, which has been successfully applied in a neural motor prosthetic system.
10:00 A Directive Antenna Array Applicator for Focused Electromagnetic Hyperthermia Treatment of Breast Cancer
Erdal Korkmaz, Omer Isik and Huseyin Sagkol (Fatih University, Turkey)
A hyperthermia applicator is designed for the treatment of breast cancer with 24 directive microstrip spiral antennas forming a hemispherical array operating at 434 MHz. All individual antennas are directed towards a target region and its phases are adapted to focus all the fields at the targeted region. The measurements are performed by submerging the in-house developed muscle, skin and fat tissue mimicking materials inside the applicator which completely stand inside distilled water. By exposing the tissue mimicking materials to focused waves the temperature distribution with respect to time is observed and presented.
10:20 The Importance of Source Polarization in Transverse Electric Time Reversal Focusing
Domenica A. M. Iero (Tesco GO, Italy); Lorenzo Crocco (CNR - National Research Council of Italy, Italy); Tommaso Isernia (University of Reggio Calabria, Italy)
Time Reversal (TR) is a well known spatial/temporal re-focusing process based on the time invariance of the wave equation in lossless media. This communication deals with an aspect of Time Reversal as applied to vector fields that has never been discussed before, that is, the polarization of the point source physically or synthetically located into the target point during the "sensing" phase of TR process. It will be shown its huge impact on TR focusing performances.
10:40 Coffee Break
11:10 A New Approach to High-Quality Patient-Specific Hyperthermia Treatment
Myles Capstick (IT'IS Foundation, Switzerland); Esra Neufeld (IT'IS Foundation, ETH Zurich, Switzerland); Marie-Christine Gosselin (IT'IS Foundation, ETHZ, Switzerland); Dimce Iliev (IT'IS Foundation, Switzerland); Julien Renggli (ZMT ZurichMedTech AG, Switzerland); Danilo Selic, Bruno Rivara and Steffen Deubler (SPEAG Schmid and Partner Engineering AG, Switzerland); Manuel Guidon (ZMT ZurichMedTech AG, Switzerland); Niels Kuster (IT'IS Foundation, ETH Zurich)
Achieving good quality hyperthermia treatments places extremely high demands on both the applicator hardware and the treatment planning software and further requires an interface between the two modalities that guarantees precise steering and treatment delivery. We propose a paradigm that addresses all these challenges with a flexible and light applicator placed on the patient using an innovative mask concept and validated software optimized for patient-specific treatment, which together allow for high-fidelity and reproducible targeted tumor heating.
11:30 Monitoring Breast Cancer Treatment Progress with Microwave Tomography and Radar-based Tissue-regions Estimation
Anastasia Baran (University of Manitoba, Canada); Douglas Kurrant and Elise Fear (University of Calgary, Canada); Joe LoVetri (University of Manitoba, Canada)
An algorithm combining microwave tomography (MWT) and a radar-based tissue region estimation technique is investigated for the purpose of monitoring tumor size changes during breast cancer treatment. The region estimation technique is used to create a spatial map of the breast anatomy that includes skin, adipose and fibroglandular regions and their average properties. This map is incorporated as a numerical inhomogeneous background into a finite element contrast source inversion (FEM-CSI) MWT algorithm. Numerical results, based on synthetically generated breast phantoms, show the combined approach reconstructs variations in the fibroglandular region that are consistent with the known structure of the tissue, and recovers the properties of the different tissue types more accurately than the radar-based or MWT techniques used alone. The enhanced resolution of the reconstructed images using the combined method allows incremental changes in tumor region to be observed.
11:50 Clinical Introduction of Novel Microwave Hyperthermia Technology: The HYPERcollar3D Applicator for Head and Neck Hyperthermia
Margarethus M. Paulides (Eindhoven University of Technology, The Netherlands); Z Rijnen, P Togni and René Verhaart (Erasmus University Medical Center, The Netherlands); Tomas Drizdal (Czech Technical University in Prague, Czech Republic); Daniel de Jong, Martine Franckena and Gerda Verduijn (Erasmus University Medical Center, The Netherlands); Gerard C. van Rhoon (Erasmus MC Cancer Institute, The Netherlands)
Clinical studies have established a strong benefit from adjuvant mild hyperthermia to radio- and chemotherapy for many tumor sites, including the head and neck. Based on simulation studies we developed the HYPERcollar applicator that allows applying focused microwave hyperthermia at 434MHz to tumors in the head and neck region. In addition, we developed a simulation based strategy using a combination of electromagnetic and temperature simulators, which is present during the treatment providing online control at applied 3D heating distribution. In this paper we describe the simulation guided development of, and early clinical experience with, a novel applicator for head and neck region, e.g. the HYPERcollar3D.
12:10 Exploiting Electromagnetic Fields to Enhance the Delivery of Therapeutics to Tumors
Sylvain Martel (Ecole Polytechnique Montreal, Canada)
Electromagnetic fields can be exploited in various ways to navigate appropriate therapeutic vectors to tumor sites using the most direct vascular routes. Such delivery approach minimizes systemic toxicity that negatively impacts healthy organs and tissues, and results in a larger ratio of therapeutics at the target site that needs treatment. Depending mostly upon the type and the characteristics of the navigable agents being used and the various physiological conditions, different approaches exploiting in various manners the control of electromagnetic fields have been developed by our research group. Here, a summary of these different approaches is provided with their appropriateness in transiting through the main potential physiological routes.
12:30 Measurement of Electrical Properties of Biological Tissue At Radio Frequencies Using Magnetic Resonance Imaging
Seung-Kyun Lee, Bulumulla Selaka, Peter Lamb and Ileana Hancu (GE Global Research, USA)
Image shading in high-field magnetic resonance imaging (MRI) due to radio-frequency (RF) wave propagation effects in biological tissue can be used to measure the electrical conductivity and relative permittivity of tissue in vivo. We describe a method to extract electrical properties of biological tissue from RF-shaded MR images without an explicit RF field mapping. The method is demonstrated on a meat sample and in the brain of a normal volunteer.

C47 Security: [C] Wave-based sensing and imaging for security applications

Propagation/Defense and Secutity
Room: João G Zarco (Pav 3C)
Chairs: Jose Martinez Lorenzo (Northeastern University, USA), Carey Rappaport (Northeastern University, USA)
9:00 A 300 GHz Imaging Radar for Standoff Anomaly Detection
Alejandro Badolato and Gorka Rubio-Cidre (Technical University of Madrid, Spain); Luis Úbeda-Medina (Universidad Politécnica de Madrid & Microwave and Radar group, Spain); Jesús Grajal (Universidad Politécnica de Madrid, Spain); Beatriz Mencia-Oliva (Universidad Politecnica de Madrid & ETSI Telecomunicacion, Spain); Antonio Pino, Borja Gonzalez-Valdes and Oscar Rubiños-López (University of Vigo, Spain)
We have developed a 3D high-resolution radar at 300 GHz with a cell resolution of 1.01x1.6x1.6 cm3 at a standoff distance of 8 m for security applications. The radar's antenna design allows single-pixel imaging with a frame rate of less than 1 Hz. Reduction of cost and power consumption are additional requirements.
9:20 A New Approach for Measuring Electromagnetic Side-Channel Energy Available to the Attacker in Modern Processor-Memory Systems
Robert Callan and Nina Popovic (Georgia Tech, USA); Alenka Zajic and Milos Prvulovic (Georgia Institute of Technology, USA)
This paper presents a new approach for measuring the EM side-channel energy (ESE) created in the EM side channel by executing different processor instructions. To illustrate the usefulness of the proposed method, we have measured EM side-channel energy among 11 different instructions from three different laptops and one desktop. The results show that ESE measurements are highly repeatable ( < 0.05). We also show that two systems with the same design result in nearly identical measured ESE values, which implies that ESE measurements are representative of an entire manufacturing run, or possibly an entire family, of systems.
9:40 Multistatic Fourier-based Technique for Radar Systems
Yuri Álvarez (Universidad de Oviedo, Spain); Yolanda Rodriguez-Vaqueiro and Borja Gonzalez-Valdes (University of Vigo, Spain); Spiros Mantzavinos and Carey Rappaport (Northeastern University, USA); Fernando Las-Heras (University of Oviedo, Spain); Jose Martinez Lorenzo (Northeastern University, USA)
Fast and accurate radar imaging techniques are mostly based on Fourier-based processing. While for monostatic setup these methodologies are widely used, multistatic systems make Fourier-based imaging more challenging: i) k-space is not uniform, requiring multidimensional interpolation methods, and ii) image is distorted when the incident spherical wave is approximated by a plane wave. This work overcomes these limitations proposing fully parallelizable solutions: i) k-space partitioning, applying interpolation in each domain, and ii) spherical wave is approximated by multiple plane waves. Benchmarking with standard SAR imaging algorithm has been performed through 3D simulation-based examples.
10:00 Multistatic Nearfield Imaging Radar for Portal Security Systems Using a High Gain Toroidal Reflector Antenna
Carey Rappaport (Northeastern University, USA); Borja Gonzalez-Valdes (University of Vigo, Spain)
A Toroidal reflector, consisting of a tilted ellipse rotated about the vertical axis, provides for multiple, overlapping high-resolution nearfield beams that form multi-view, true multistatic mm-wave imaging for security applications. Modeled results indicate the PSF on a torso target is wide and short, allowing for quickly computed 2D images which can be stacked to reconstruct detailed 3D surfaces.
10:20 Focal Plane and Synthetic Aperture Array Alternatives in a 340 GHz Imaging Radar
Ken Cooper, Theodore Reck and Robert Dengler (Jet Propulsion Laboratory, California Institute of Technology); Nuria LLombart (Delft University of Technology, The Netherlands)
We have developed a compact eight-element 340 GHz transceiver array to accelerate the frame rate of standoff imaging radars for personnel screening applications. The clothing penetration of the 340 GHz radar is found to be far better than a comparable system operating at 680 GHz, with the tradeoff being a higher antenna-diameter-to-standoff-range ratio. However, the field of view (FOV) for any high-resolution imaging radar can be impractically narrow when using a fixed-focus aperture because of beam defocusing at high deflection angles. To investigate ways of overcoming this limitation, we have analyzed a novel synthetic aperture technique that uses an off-axis fast-rotating reflector to generate virtual circular arrays of receiver elements, resulting in far wider FOVs than is currently achieved.
10:40 Coffee Break
11:10 On-the-Move Millimeter Wave Imaging System Using Multiple Transmitters and Receivers
Borja Gonzalez-Valdes (University of Vigo, Spain); Yuri Álvarez and Javier Gutiérrez-Meana (Universidad de Oviedo, Spain); Carey Rappaport (Northeastern University, USA); Fernando Las-Heras (University of Oviedo, Spain); Antonio Pino (University of Vigo, Spain); Jose Martinez Lorenzo (Northeastern University, USA)
A novel imaging system able to create real time radar images for personnel security screening is presented. The system uses multiple mm-wave transmitters and receivers placed along a hallway in a multistatic configuration. The layout consists of two flat panels of receivers placed on opposite walls. Transmitters are located around the hallway to provide multiple illumination angles. The main novelty is the fact of whole body imaging taking advantage of the person's movement to increase the number of observation angles. The imaging is performed as the person being screened continuously moves through the hallway, then combining the recovered image for every position as the different frames of a video. 3D simulation results showing the feasibility of the proposed system are presented.
11:30 Single-Transceiver Compressive Antenna for High-Capacity Sensing and Imaging Applications
Jose Martinez Lorenzo and Juan Heredia-Juesas (Northeastern University, USA); William Blackwell (MIT Lincoln Laboratory, USA)
This paper presents a novel singletransceiver compressive reflector antenna for highcapacity sensing and imaging applications. The compressive antenna generates a spatial code in the imaging region, which is dynamically changed by using a mechanical rotation of the reflector. The scattered data measured by the single transceiver is processed using compressive sensing techniques in order to perform a 3D reconstruction of the object under test. Preliminary results show that a compressive reflector antenna outperforms a traditional reflector antenna in terms of sensing channel capacity and image reconstruction accuracy.
11:50 Advanced Fully-Electronic Personnel Security Screening Technology
Sherif Sayed Ahmed (Rohde & Schwarz GmbH & Co. KG, Germany)
The screening of personnel at airports or critical infrastructure building is a challenging task, where a balance between the demanded security level and the concern of infringing their privacy is needed. This accordingly requires advanced fast scanning methods delivering the needed comfort with an efficient operation. This paper presents modern screening systems based on an established millimeter-wave imaging technology. Additionally, a discussion on the various deployment possibilities is made showing the capabilities of a flexible and modular utilization.
12:10 Passive Imaging Strategies for Real-time Wireless Localization of Non-cooperative Targets in Security Applications
Federico Viani (ELEDIA@UniTN - University of Trento & ELEDIA Research Center, Italy); Fabrizio Robol and Enrico Giarola (ELEDIA Research Center, Italy); Paolo Rocca and Giacomo Oliveri (University of Trento & ELEDIA Research Center, Italy); Andrea Massa (University of Trento, Italy)
The localization of passive targets has been widely investigated in the field of security applications. In such a context, the target is non-cooperative, i.e. transceiver-free and not actively associated to any monitoring system. These constraints make the detection and localization process challenging from the sensing technology viewpoint. Standard solutions adopt dedicated and complex sensors (e.g., video, audio, infrared sensors) that require accurate installation, calibration, and maintenance. Alternative passive imaging strategies based on the exploitation of wireless signals transmitted by low-cost devices have been also proposed in the state-of-the-art. In this paper, the advantages and limitations of such solutions are investigated and the concept of opportunistic exploitation of standard wireless architectures is introduced in order to show and discuss the applicability to security-related applications.
12:30 Wave-based Sensing and Imaging for Security Applications
Kristofer Roe (Smiths Detection Inc., USA)
This paper will describe a people screening system based on active mm-wave reflect array technology. Technical details of the Smiths Detection eqoTM system, imaging capability and the use of the system for security screening are detailed.

C7 AMTA1: [C] AMTA/EurAAP Diagnostics, imaging, and post-processing in antenna measurements

Measurements/Bridging other Areas
Room: Paulo da Gama (Pav 5B)
Chairs: Daniël J Janse van Rensburg (NSI-MI Technologies & Nearfield Systems Inc, USA), Sergiy Pivnenko (Antenna Systems Solutions, Denmark)
9:00 Extending the Plane Wave Based Fast Irregular Antenna Field Transformation Algorithm for Amplitude-Only Data
Carlos Lopez (Technische Universität München, Germany); Raimund A. M. Mauermayer (Independent Researcher, Germany); Thomas F. Eibert (Technical University of Munich (TUM) & Chair of High-Frequency Engineering (HFT), Germany)
The Fast Irregular Antenna Field Transformation Algorithm (FIAFTA) is extended and employed to construct a near-field far-field transformation algorithm using amplitude-only data. The problem is posed as a minimization of a quadratic functional and it is solved in an iterative fashion using FIAFTA and the nonlinear conjugate gradient method. Since the linear radiation operator inside the nonlinear formulation is evaluated with FIAFTA, its characteristics are inherited and have a beneficial effect when solving the nonlinear problem. Numerical results show the usefulness of the method.
9:20 Characterizing the Near Field Strength of ISS-RapidScat Reflector Antenna From Measurement Data Using Spectral Back Projection Method
Yahya Rahmat-Samii (University of California, Los Angeles (UCLA), USA); Luis Amaro (Jet Propulsion Laboratory, USA); Joshua M Kovitz (Georgia Tech Research Institute, USA)
A newly developed instrument, known as the Rapid Scatterometer (ISS-RapidScat), has been designed to replace QuickScat and SeaWinds in measuring ocean surface winds. The new design utilizes much of the engineering model hardware from SeaWinds. ISS RF safety requirements necessitated a blanker circuit that was designed to manage ISS-RapidScat interference on sensitive nearby objects such as spacecraft and humans. This required a detailed knowledge of the antenna near-field distribution and absolute strength, which can be challenging to obtain experimentally. This paper outlines a procedure to determine the near-field values with the knowledge of the measured far-field patterns and the radiated power. The accuracy of the method has been validated through many simulations.
9:40 Configurable Robotic Millimeter-Wave Antenna Facility
Jeffrey Guerrieri and Joshua Gordon (National Institute of Standards and Technology, USA); David Novotny (US National Institute of Standards and Technology, USA); Mike Francis (NIST, USA)
This paper presents the development of the Configurable Robotic Millimeter-Wave Antenna (CROMMA) facility by the Antenna Metrology Lab at the National Institute of Standards and Technology (NIST). NIST set out to develop an antenna measurement facility that would be reconfigurable to different near-field antenna measurement geometries and perform antenna measurements from 100 to 500 GHz. An industrial robotic arm, hexapod and precision rotator were integrated to make a unique antenna measurement facility. A laser tracker with the ability to monitor and record the six degrees of freedom of a target was employed to measure and provide feedback used to correct the actual path of the robotic arm and position of the hexapod and rotator.
10:00 Study of Daily Tissue Changes Through Breast Monitoring with Time-Domain Microwave Radar
Emily Porter (University of Texas at Austin, USA); Riza Kazemi (University of British Columbia, Canada); Adam Santorelli (National University of Ireland, Galway & Translational Medical Device Lab, Ireland); Milica Popović (McGill University, Canada)
The aim of this study is to monitor daily breast tissue content change, as perceived by our time-domain microwave radar system. We here present results obtained by tracking a healthy patient volunteer through daily breast scans over the 28-day timeframe corresponding to one menstrual cycle. Our system uses a multistatic radar approach, contains 16 wideband antennas, and is integrated into a clinical interface. The resulting data confirm that small variations in the breast tissue are evident over the 28-day period, and that, unlike malignant growths, the changes fluctuate (appear and disappear) over several days.
10:20 Phase Retrieval Procedure for Microwave Linear Arrays
Benjamin Fuchs (University of Rennes 1 - IETR, France); Laurent Le Coq (University of Rennes 1 & IETR, France)
A methodology to solve the phase retrieval problem arising in microwave linear array is proposed. The goal is to recover the complex array excitations from phaseless measurements of the far field. An approach combining convex optimization (to solve the phase retrieval problem) and two measurement runs (to mitigate the ambiguity problem) has been developed and numerically assessed in various representative examples. These results show that under appropriate conditions of noise and sampling, it is possible to uniquely retrieve the complex excitations of linear arrays from phaseless measurements.
10:40 Coffee Break
11:10 Source Reconstruction Technique for Planar Arrays of Wide Slots
Makoto Sano (Toshiba Corporation, Japan); Manuel Sierra-Castañer (Universidad Politécnica de Madrid, Spain); Jiro Hirokawa and Makoto Ando (Tokyo Institute of Technology, Japan)
A source reconstruction technique for wide-slot arrays is presented. The excitation coefficients are reconstructed from the plane wave spectrum (PWS). The shape of the field distribution on a wide slot is considered in the calculation of the PWS. The proposed algorithm is applied to the simulated near-field data of a wide-slot array with element failures, and the excitation coefficients are reconstructed. It is shown that the element failures are clearly located.
11:30 Investigation of Spherical Higher Order Modes Sources in Antenna Measurement Probe Design
Lars Foged, Andrea Giacomini, Francesco Saccardi and Lucia Scialacqua (Microwave Vision Italy, Italy)
Classical probe corrected Spherical Near Field (SNF) measurement assumes a |μ| = 1 probe [1]-[3]. This requirements is needed to fully compensate the effect of the probe during the NF/FF transformation [3]. If the probe has an higher order mode content, a residual error will affect the measured pattern (probe modal truncation). This requirement leads to challenging probe designs especially if the required bandwidth is wide and/or there is a limitation on the acceptable dimension. As a consequence, in many practical cases, higher order spherical modes could be radiated. In this paper, the source of higher order spherical modes of the MVI SP1100 probe is investigated using MV-INSIGHT software [6] which reconstructs equivalent currents starting from the measured NF. The equivalent currents associated to higher order modes have been computed on a conformal geometry encompassing the probe. In this way, the origin of such higher order modes has been deduced.
11:50 Comparison of Different Antenna Diagnostics Techniques with Limited Far Field Data Input
Sergiy Pivnenko (Antenna Systems Solutions, Denmark); Cecilia Cappellin (TICRA, Denmark)
In this paper, three different antenna diagnostics techniques are compared for the case when the input data represent only few complete cuts or a two-dimensional grid with a limited angular sector. The techniques are applied to several different antennas: a high-gain offset reflector antenna, a large slotted waveguide array, and a small slotted waveguide array with an error. Systematic investigation is carried out on providing a relation between the number of the input antenna cuts or the size of the angular sector and quality of the obtained distribution of the equivalent currents and extreme near fields.
12:10 Imaging-based Classification Algorithms on Clinical Trial Data with Injected Tumour Responses
Yunpeng Li (McGill University, Canada); Emily Porter (University of Texas at Austin, USA); Mark Coates (McGill University, Canada)
Current microwave breast cancer imaging algorithms focus primarily on generating an image, and provide little machinery for interpretation of the image. Within-image contrast is commonly used as a performance metric, but a better reflection of the tumour detection capability of an algorithm is the difference between the maximum voxel intensities observed in images from scans of tumour-free and tumour-bearing breasts. This paper extends existing imaging algorithms by incorporating an automatic tumour detection technique that involves classification based on maximum voxel intensities. We compare results obtained from different algorithms on the data collected from healthy breast scans performed during clinical trials of a microwave radar system. We artificially inject tumour signals that are constructed based on the transmission properties of the radar system and the estimated breast tissue properties. The results provide insights into which algorithms are sufficiently robust to handle discrepancies between the real measurement data and the modeling assumptions.
12:30 Study of the Influence of Mechanical Errors in Diagnostics Applications by Means of Statistical Analysis
Ana Arboleya (Universidad Rey Juan Carlos, Spain); Jaime Laviada and Yuri Álvarez (Universidad de Oviedo, Spain); Fernando Las-Heras (University of Oviedo, Spain)
Mechanical errors introduced by a planar measurement range and their effect on diagnostics applications have been analyzed. The study is based on Montecarlo statistical analysis by means of an error simulation tool for antenna measurements and diagnostics applications. The effect of each type of error and its contribution to the final uncertainty of the system can be used to establish the error bounds and tolerance of the measurement system to mechanical inaccuracies for the implemented setups. An example on how different types of errors, regarding the positioning system, influence the determination of the size of a horn antenna aperture in the W band is evaluated.

Wednesday, April 15 9:00 - 10:40 (Europe/Berlin)

R2 LeakyAnt: Slotted-, guided- and leaky-wave antennas

Room: Bartolomeu Dias (Aud 4)
Chairs: Miguel Ferrando-Rocher (Universidad de Alicante & Universitat Politècnica de València, Spain), Lei Wang (Heriot-Watt University, United Kingdom (Great Britain))
9:00 Gain Enhanced H-plane Gap SIW Horn Antenna with Phase Correction
Lei Wang (Heriot-Watt University, United Kingdom (Great Britain)); Marc Esquius Morote (Ecole Polytechnique Fédérale de Lausanne, Switzerland); Xiaoxing Yin (Southeast University, China); Juan R Mosig (Ecole Polytechnique Federale de Lausanne, Switzerland)
The electromagnetic field phase distribution in horns' apertures is affected by the horn flaring and is usually not uniform, resulting in a lower antenna gain. This paper presents an H-plane SIW horn antenna with the aperture phase corrected by some gaps on the H-plane metallic walls, to enhance the antenna gain. To achieve a better radiation and impedance matching, some planar tapered-ladder transitions are printed just after the horn aperture. Simulations in HFSS software, including a probe excitation, have shown good phase correction and hence increased gain, while also providing good impedance matching. The designed compact Ka-band antenna achieves an enhanced gain of 10.1 dBi at 34 GHz, and an impedance bandwidth of 4.33 GHz.
9:20 Low Cost Switchable RHCP/LHCP Antenna for SOTM Applications in Ka-band
José Ignacio Herranz-Herruzo and Alejandro Valero-Nogueira (Universidad Politécnica de Valencia, Spain); Miguel Ferrando-Rocher (Universidad de Alicante & Universitat Politècnica de València, Spain); Bernardo Bernardo-Clemente (Universitat Politècnica de València, Spain); Régis Lenormand, Antonin Hirsch, Jean-Luc Almeida, Mathieu Arnaud and Lyonel Barthe (Thales Alenia Space, France)
This paper describes the main features of TX and RX antenna panels for low cost Ka-band SOTM (SATCOM on-the-move) terminal. In addition, enhanced DVB-S2 waveform modem developed by Thales Alenia Space is also described. This modem has led to significant cost reduction. The terminal will be compliant with all capacities associated with communication on-the-move supplying higher quality, better performance and faster speed services than the current available solutions in Ku-band.
9:40 A Sectorial Fabry – Perot Antenna for Radar Application
Marco Degiorgi, Filippo Costa and Simone Genovesi (University of Pisa, Italy); Agostino Monorchio (University of Pisa & CNIT, Italy)
A Fabry – Perot (FP) antenna for radar systems application is proposed. The investigated design allows to fulfill all the radar application requirements with a simple and robust layout and it is preferable to conventional linear arrays for a number of reasons. The required asymmetric far – field pattern has led to the design of a sectorial FP with a lateral shielded cavity. In order to avoid the need of multiple sources to achieve the requested antenna gain performance, a high reflective FSS (Frequency Selective Surface) has been employed as a partially reflective screen (PRS). A prototype of this antenna was realized and the comparison between measurements and simulations is reported.
10:00 RLSA Bessel Beam Launchers Using Hankel Waves
Santi Concetto Pavone (Università degli Studi di Catania, Italy); Mauro Ettorre (University of Rennes 1 & UMR CNRS 6164, France); Matteo Albani (University of Siena, Italy)
In this paper the focusing capabilities of a radiating aperture taking on an Hankel-like distribution are demonstrated. In the case of an infinite aperture distribution, an analytical approach is followed. In the case of an inward Hankel wave, the ideal non-diffractive Bessel beam shape is observed for the longitudinal z-component of the electric field in a conical region close to the axis of symmetry of the aperture. In the finite case, an asymptotic approximation is used to evaluate the diffractive contributions due to the aperture truncation and to verify the conclusions of the infinite case. A radial waveguide loaded with annular slots is therefore designed and optimized as a practical implementation of the proposed Bessel beam launcher validating the theoretical results.
10:20 SIW Pillbox Antenna Integrating Monopulse Phase Comparison Technique
Karim Tekkouk (Tokyo Institute of Technology, Japan); Mauro Ettorre (University of Rennes 1 & UMR CNRS 6164, France); Laurent Le Coq (University of Rennes 1 & IETR, France); Ronan Sauleau (University of Rennes 1, France)
A multi-beam pillbox antenna system incorporating monopulse phase comparison technique is proposed in the 24-GHz band. The antenna architecture combines the scanning capabilities of pillbox configurations and enhanced resolution of two-quadrant monopulse technique. This approach avoids mechanical orientation of the antenna system for tracking applications. The beam is scanned in E-plane over a field of view of ±40°, and sum/difference patterns are generated in H-plane. Around the design frequency, f=24.15 GHz, the measured null depth is better than -16dB for all difference beam patterns. The measured reflection bandwidth for VSWR<2 equals 4.5%, and the isolation between the sum and difference input ports is better than 17dB over the [23.5-24.6] GHz band.

Wednesday, April 15 9:00 - 12:50 (Europe/Berlin)

S2 SatProp: Satellite Propagation

Room: Tristão V Teixeira (Pav 5A)
Chairs: Bertram Arbesser-Rastburg (Spacetec Partners, Austria), Laurent Castanet (ONERA, France)
9:00 Fading and Scattering Due to Trees in L to Ka Band Propagation Simulations
Jonathan Israel (ONERA - The French Aerospace Lab, France); Anthony Pajot (OKTAL-SE, France)
Vegetation effects on electromagnetic wave propagation can have a strong impact on many localization or communication systems. This situation explains an increasing interest in the development of tree attenuation and scattering models which could help in the characterization of complex propagation environments. In this paper, we propose a general methodology to compute propagation effects due to a set of trees based on a point scattering model and the multiple scattering theory. We show its capacity to generate realistic simulations in good accordance with S band measurements.
9:20 Initial Results From a Measurement Campaign for Low Elevation Angle Links in Different Environments
Jan Zeleny (Czech Technical University, Czech Republic); Fernando Pérez-Fontán (University of Vigo, Spain); Pavel Pechac (Czech Technical University in Prague, Czech Republic)
Unmanned aerial vehicles (UAV) are being used more widely in civil applications nowadays and photomaps, or aerial monitoring, demand an enormous amount of transmitted data in high frequency links. In the new generation of wireless communication standards, different propagation channel models are recommended for system simulations to develop new hardware. Every channel model needs to be validated by experimental measurement data, from pre-defined scenarios such as urban, suburban, sparse housing estate, open field and vegetation covered area. A reliable data harvesting is a key issue. Hence a low cost measurement campaign is being developed.
9:40 Land Mobile Satellite Propagation Characteristics From Knife-Edge Diffraction Modeling and Hemispheric Images
Marie Rieche and Alexander Ihlow (Ilmenau University of Technology, Germany); Thomas Heyn (Fraunhofer IIS, Germany); Fernando Pérez-Fontán (University of Vigo, Spain); Giovanni Del Galdo (Fraunhofer Institute for Integrated Circuits IIS & Technische Universität Ilmenau, Germany)
This contribution investigates the characterization of the Land Mobile Satellite (LMS) channel by estimating the path gain from Knife-Edge Diffraction (KED) modeling and hemispheric images. The geometric parameters for the KED model are derived from images of the upper hemisphere. This enables the prediction of the signal attenuation for arbitrary satellite positions. The impact of the unknown path distance between the top of the obstacle and the mobile terminal is investigated. Moreover, we compare the results with measured power levels.
10:00 Measurement of Instantaneous Frequency Scaling for Q/V-Band
Johannes Ebert and Karin Plimon (Joanneum Research, Austria); Michael Schmidt (Researcher & Joanneum Research, Austria); Juan J. Rivera Castro (European Space Agency, The Netherlands)
The Aldo Paraboni Payload on the Alphasat satellite consists of two Q/V-band transponders and two beacons at Ka- and Q-band. During the first period of experimentation the satellite transponders were set up in loopback mode. By comparison of the Q-band beacon with the Q/V-band transponder loop, the instantaneous frequency scaling between Q and V band can be determined. In the present short paper, the setup of the experiment and processing of the data is illustrated along with first results. In the full paper, this experiment will be extended with detailed statistical distributions and a comparison with the ITU-R P.618-11 recommendations.
10:20 Evaluation of Inter-Annual Variability of Rainfall Rate and Rain Attenuation Based on the ITU Rec P.678
Flávio M. da Silva Jorge (European Space Agency, The Netherlands); Armando Rocha (University of Aveiro & Instituto de Telecomunicações, Portugal); Susana Mota (University of Aveiro & Institute of Telecommunications, Portugal)
The inter-annual variability of rainfall rate and rain attenuation statistics is an important subject, since it defines the confidence intervals that an operator must consider in order to guarantee a certain QoS. This variability can now be assessed through the ITU recommendation P.678-2. The present work perform a critical assessment to the suitability of this recommendation based on 8 years of database collected in Aveiro, Portugal, with the former HotBird-6 satellite.
10:40 Coffee Break
11:10 Performance of Site-Diversity Satellite Communication Systems in Equatorial Malaysia Investigated Through Weather Radar Data
Hong Yin Lam (Universiti Tun Hussein Onn Malaysia, Malaysia); Lorenzo Luini (Politecnico di Milano, Italy); Jafri Din (Universiti Teknologi Malaysia, Malaysia); Carlo Capsoni (Politecnico di Milano, Italy); Athanasios D. Panagopoulos (National Technical University of Athens, Greece)
In this work, we exploit two years of weather radar data collected at Johor (Malaysia) to simulate a site diversity SatCom system operating at 18.9 GHz with two links point to the WINDS satellite (elevation angle equal to 44.03°). The effectiveness of the dual-link diversity scheme is assessed by calculating the single- and joint-site probability distributions of attenuation, as well as the diversity gain. Both results, calculated as a function of separation distance, indicate a definite reduction of the rain attenuation affecting the overall communication system, hence a clear improvement in the Quality of Service (QoS) that can be provided to the users in this heavy rain region. In addition, the radar derived diversity gain values have been compared with those obtained from the latest version of the ITU-R Recommendation P.618 model to design site diversity systems: results indicate quite a significant discrepancy, especially at high attenuation levels
11:30 Joint Effects of Clouds and Rain on Ka-Band Earth Observation Data Downlink Systems
Lorenzo Luini and Carlo Capsoni (Politecnico di Milano, Italy)
This contribution addresses the evaluation of the simultaneous impact of clouds and rain on a Ka-band Data Downlink System involving a Low Earth Orbit (LEO) satellite for Earth Observation. To this aim, MultiEXCELL (Multi EXponential CELL) and SMOC (Stochastic MOdels of Clouds), two physically-based models recently developed to synthesize realistic rain and cloud fields as large as 10 km×200 km×200 km (height×width×depth), are employed. Taking advantage of their physical soundness, the two models are combined to derive the simultaneous attenuation due to rain and clouds on a Earth-LEO link operating at 26 GHz. Results obtained for Rome, NY, USA indicate that the data downlink system is affected by clouds for approximately 72% of the visibility time and that a 30-dB margin would be required to counteract the attenuation due to rain and clouds for 99.9% of the visibility time.
11:50 Weather Effects Mitigation At Ka Band by Using Radiometeorological Model Forecast in Deep Space Downlinks
Marianna Biscarini and Frank S. Marzano (Sapienza University of Rome, Italy); Luciano Iess (Univerity of Rome La Sapienza, Italy); Mario Montopoli (CETEMPS - University of L'Aquila, Italy); Klaide De Sanctis (HIMET, Italy); Saverio Di Fabio (CETEMPS, Italy); Maria Montagna (SciSys @ ESA, Germany); Mattia Mercolino and Marco Lanucara (European Space Agency, Germany)
Deep space exploration missions are aimed at acquiring information about the solar system and a significant communication capacity has to be planned to transfer data for such very large distances. Terrestrial atmospheric impairments on the space-to-Earth propagating signal are the most responsible for the signal degradation thus reducing the channel temporal availability. In this work weather forecast models, coupled with microphysically-oriented radio-propagation models, are described in order to evaluate atmospheric effects at Ka-band. Estimation data return techniques are summarized and numerical results in a simulated operational scenario are illustrated in terms of received data volume using the BepiColombo mission as a baseline example.
12:10 Mobile and Nomadic Measurements of the LMS Propagation Channel At Ku and Ka Bands
Joel Lemorton and Xavier Boulanger (ONERA, France); Mehdi Ait-Ighil (ONERA - The French Aerospace Lab, France); Fernando Pérez-Fontán (University of Vigo, Spain); Sebastien Rougerie and Frederic Lacoste (CNES, France)
The purpose of the paper is to present a series of measurements of the mobile and nomadic satellite propagation channels in Ku and Ka bands, covering mainly the environments encountered by vehicles of public transportation. The first campaign "without leaves" conducted in April 2014 provided a good dataset of Ku and Ka-band attenuation caused by four different kinds of trees. Mobile Ku-band measurements gave acquisitions on much longer path sections including railway or tramway sections and sections with evenly spaced trees. A second campaign was conducted "with leaves" in June and July 2014.
12:30 Statistical Significance of Specific Rain Attenuation Dependence on Geographic and Climatic Conditions
Michael Schönhuber and Karin Plimon (Joanneum Research, Austria); Merhala Thurai (Colorado State University, USA)
In satellite communications, among all atmospheric effects, rain has the biggest impact on signal transmission, causing attenuation, polarization rotation and phase shift. Precise knowledge of statistical expectations for rain attenuation thus is of high practical relevance. Whereas often a unique relationship between rain rate and specific attenuation is used, it is well known that the variability of drop size distributions (DSDs) is big and induces variability also in the specific attenuation vs. rain rate relationship. In this study evaluations of DSD measurements for two geographically and climatically different locations are evaluated and compared against the relevant ITU-R model, confirming the known geographic dependence of DSD shapes. To open such knowledge for practical applications, a proposal is made, to illustrate how statistical key parameters of DSD characteristics may be included into the ITU-R DBSG3 database.

Wednesday, April 15 11:10 - 12:50 (Europe/Berlin)

S8 MetaSpace: Advanced RF materials, metamaterials and EBG for Space Applications

Room: Bartolomeu Dias (Aud 4)
Chairs: Mauro Ettorre (University of Rennes 1 & UMR CNRS 6164, France), Tiago Morgado (Instituto de Telecomunicações and University of Coimbra, Portugal)
11:10 Transformation Optics SW-Based Devices
Mario Junior Mencagli (University of North Carolina at Charlotte, USA); Enrica Martini (University of Siena, Italy); David González-Ovejero (Centre National de la Recherche Scientifique - CNRS, France); Stefano Maci (University of Siena, Italy)
Transformation optics (TO) is exploited to design devices able to control the propagation path of surface waves (SWs). The proposed methodology consists in simple formulas which link the parameters of the transformation to the local SW wavevector. The space-dependent wavevector distribution is eventually implemented by sub-wavelength patches printed on a grounded slab. Two TO SW-based devices are presented.
11:30 Optically Reconfigurable Metacheckerboard
Mario Junior Mencagli (University of North Carolina at Charlotte, USA); David González-Ovejero (Centre National de la Recherche Scientifique - CNRS, France); Enrica Martini (University of Siena, Italy); Brigitte Loiseaux (Thales Research & Technology, France); Charlotte Tripon-Canseliet (Université Pierre et Marie Curie, France); Jean-Maurice Chazelas (Thales Aerospace Division, France); Stefano Maci (University of Siena, Italy)
This paper presents a new type of metasurface (MTS) particularly suited for the integration of optically controlled switches. It consists of a checkerboard-type layout, made of electrically small complementary metallic patches and apertures. The characteristics of the supported electromagnetic field depend on whether the patches' vertexes are interconnected or not. In particular, in a structure containing both connected and disconnected patches, the field is confined in the region where patches are connected. This feature offers the possibility of designing arbitrary transmission line paths (and therefore beam forming networks) on the checkerboard MTS (CBMS) by dynamically changing the vertex connections with an optical control. Preliminary experimental results are presented.
11:50 Broadband Fabry-Perot Type Sub–Wavelength Profile Antenna
Konstantinos Konstantinidis, Alexandros Feresidis and Peter S Hall (University of Birmingham, United Kingdom (Great Britain))
In this paper a new concept for designing subwavelength-profile and broadband high-gain leaky-wave antennas is presented. It is based on novel multi-layer periodic arrays for sub-wavelength Fabry-Perot leaky-wave antennas with enhanced bandwidth performance. Two double-layer periodic arrays of dissimilar dimensions are designed and optimized, each double-layer array consisting of an Artificial Magnetic Conductor (AMC) and a Partially Reflective Surface (PRS) printed on either side of a dielectric substrate. They are separated by quarter wavelength from a ground plane and from each other, creating two air cavities with a total profile of λ/2. A broadband feeding mechanism is employed. The proposed antenna has been simulated in CST Microwave StudioTM, achieving 16.3dBi realized gain with 8% bandwidth.
12:10 Efficient Characterization of a CPW Series Capacitor in Ku Band
Juan Duran and Cedric Martel (ONERA, France); Gaëtan Prigent (LAAS-CNRS, France); Olivier Pascal (Université de Toulouse - UPS INPT CNRS, France)
The symmetric series gap in the central strip of a Coplanar Waveguide (CPW) is described and characterized for Ku Band applications. The method, based on curve fitting techniques, is proved very efficient for its application domain. The mechanical dimensions of the cell are bounded in order to reduce the cost of production of the line while keeping small transverse dimensions to allow the presence of neighboring lines even in relatively constrained spaces.
12:30 Circularly Polarized Ultra-Thin Antennas for Space: Examples of Realizations
Marco Faenzi, Francesco Caminita and Enrica Martini (University of Siena, Italy); Paolo De Vita (IDS Ingegneria Dei Sistemi S. p. A, Italy); Marco Sabbadini (Esa Estec, The Netherlands); Stefano Maci (University of Siena, Italy)
This paper is intended to outline the theoretical basis and the design procedure for ultraflat, low mass, low envelope and extremely cost effective metasurface antennas. The two proposed prototypes operate at the X-band (at an RX center frequency of 7.165GHz and at a TX center frequency of 8.425GHz) and are suitable for ESA deep space missions. Devices showing these characteristics have in fact an implicit appeal for applications in space environment, which typically imposes strict constraints in terms of structure bulkiness. Metasurface antennas perfectly comply with these requisites. Despite the extreme low profile characteristics, it can be shown that an extremely precise control of the polarization and gain performance is possible by controlling the interaction between the exciting surface wave and the metasurface. Simplicity of the feeding structure is another key point that renders this kind of radiators extremely appealing for the space environment.

W1 NetPlan: Network Planning, Optimisation and Simulation

Propagation/Wireless Networks
Room: Afonso de Albuquerque (Pav 3B)
Chairs: Rausley Adriano Amaral de Souza (National Institute of Telecommunications (INATEL), Brazil), Christian Schneider (Ilmenau University of Technology, Germany)
11:10 A Multi-objective Approach to Indoor Wireless Heterogeneous Networks Planning
Sotirios Goudos (Aristotle University of Thessaloniki, Greece); David Plets (Ghent University - imec, Belgium); Ning Liu and Luc Martens (Ghent University, Belgium); Wout Joseph (Ghent University/IMEC, Belgium)
We present a multi-objective optimization approach for indoor wireless network planning subject to constraints for exposure minimization, coverage maximization and power consumption minimization. We consider heterogeneous networks consisting of WiFi Access Points (APs) and Long Term Evolution (LTE) femtocells. We propose a design framework based on Multi-objective Biogeography-based Optimization (MOBBO). The results of the proposed method indicate the advantages and applicability of the multi-objective approach.
11:30 Indoor-to-Outdoor Channel Characterization for Modeling and Prediction of Interference in Next Generation Wireless Networks
Sanaa Hamid Mohamed (Khalifa University, Abu Dhabi); Arafat Al-Dweik (Khalifa University, United Arab Emirates); Maysam Mirahmadi (The University of Western Ontario, Canada); Khalid Mubarak (Khalifa University, Abu Dhabi); Abdallah Shami (Western University, Canada)
This paper presents an indoor-to-outdoor signal propagation model based on exhaustive measurements campaign. The conducted measurements considered an indoor transmitter and an outdoor receiver to analyze the interference in future 5G networks with femtocells overlaying macrocells. To propose a practical model, architectural details of the buildings and the exact position of the transmitter, which are not typically known to the network designers are considered random in the proposed model, which resulted in a stochastic non-site-specific model for application in 5G networks.
11:50 Mobile Networks Optimization Using Open-Source GRASS-RaPlaT Tool and Evolutionary Algorithm
Darko Šekuljica, Andrej Vilhar and Matjaž Depolli (Jozef Stefan Institute, Slovenia); Andrej Hrovat (Jožef Stefan Institute, Slovenia); Igor Ozimek and Tomaz Javornik (Jozef Stefan Institute, Slovenia)
The process of LTE and LTE-A mobile networks optimization for 900MHz radio signal using the open-source GRASS-RaPlaT tool and evolutionary algorithm is described. The motivation for such optimization is to reduce operational costs and to maximize network efficiency. The tool takes into account terrain profile maps and calculates path loss by applying state-of-the-art statistical models. The optimization has been tested on a selected area in Ljubljana, Slovenia. Criteria functions are defined and maximized in the process. The obtained results show that the key network characteristics such as signal coverage, carrier-to-interference ratio and network capacity can be increased by tuning base station parameters like transmission power, antenna direction and location.
12:10 Required Number of Propagation Scenarios for Acceptable Reproduction of Spectral Efficiency Distribution in (heterogeneous) Network Simulations
Milan Narandžić (University of Novi Sad, Serbia); Christian Schneider (Ilmenau University of Technology, Germany); Wim A. Th. Kotterman (Ilmenau University of Technology); Reiner S. Thomä (Ilmenau University of Technology, Germany)
The necessary number of propagation scenarios in a generic channel model can be argued from different perspectives. When ensuring proper reproduction of channel sounding experiments, the model should reproduce the statistics of the measurements. In this context, the quantification of the distance between reference scenarios of WINNER/ITU-R model enables the controlled reduction of the number of scenarios, and consequently, of the simulation complexity. However, if different environmental characteristics map onto similar system performance we should reconsider further model approximation or reduction of the number of scenarios. In this paper we evaluate the similarity of spectral efficiency distributions between WIM propagation scenarios. The obtained results are related to previously calculated inter-scenario distances based on mean Kullback-Leibler divergence, and correlations are discussed.
12:30 Simultaneous Sensing-Transmission in Cognitive Radio Networks Under Spatiotemporally Collaborative Techniques
Mário Henrique Pereira Alves (Instituto Nacional de Telecomunicações, Brazil); Rausley Adriano Amaral de Souza (National Institute of Telecommunications (INATEL), Brazil); Adoniran Judson Braga (Universidade de Brasília, Brazil)
A main concern in recent research is to maximize the throughput of the secondary cognitive radio network under the restriction of avoiding interference to the primary network. Traditionally, a specific interval is devised to the task of spectrum sensing, which penalizes the secondary network throughput. Nowadays, the continuous sensing mode has been extensively studied. In this approach, secondary receiving nodes continuously sense the spectrum while other secondary users simultaneously transmit in the same frequency band. We compare, under the continuous sensing approach, the performances of centralized spatiotemporally cooperative spectrum sensing techniques. The altered versions of well-established generalized likelihood ratio test and maximum-minimum eigenvalue detection techniques are considered. We consider the sample fusion, the decision fusion and the eigenvalue fusion technique. It is shown that, in spite of the intrinsic interference present in the continuous mode, this approach is flexible in terms of the sensing time, allowing for better sensing performance.

Wednesday, April 15 11:10 - 12:10 (Europe/Berlin)

WS6 Altair: Application of Numerical Techniques to the Solution of Practical Antenna Problems with FEKO

Industrial Workshop
Diogo de Silves (Room 1.08)

Wednesday, April 15 14:00 - 15:00 (Europe/Berlin)

Poster A3: Antennas Poster Session 3

Room: Gil Vicente (Hall 5)
Chairs: Duarte de Sousa Fonseca (Loughborough University, United Kingdom (Great Britain)), Asimina Kiourti (The Ohio State University, USA)
Simultaneous Two-port Injection Matched Antenna
Yasin Kabiri (The University of Birmingham, United Kingdom (Great Britain)); Peter Gardner and Costas Constantinou (University of Birmingham, United Kingdom (Great Britain))
Earlier, based on the injection matching theory, an electrically small antenna was produced in which one of the ports was exploited to match the other port. In this paper it is demonstrated that by using the injection matching theory, simultaneous matching at both ports can also be achieved which improves the overall efficiency of the two-port injection matched antenna. Based on this a two port electrically small chassis antenna is produced which benefits from a wide bandwidth as well as high efficiency.
Electrically Small Modified Planar Inverted-F Antenna
Saad Mufti, Alan Tennant and Luke Seed (University of Sheffield, United Kingdom (Great Britain))
A novel modified planar inverted-F antenna (PIFA) is designed on a cylindrical FR4 substrate with dimensions 50 mm (diameter) x 4 mm (thickness). The optimized design is extremely electrically small, with a measured voltage standing wave ratio (VSWR) 3:1 bandwidth of 49 MHz at 530 MHz, and can be scaled down in physical size to operate in the 2.45 GHz band.
Implementation and Wireless Readout of Passive UHF RFID Strain Sensor Tags Based on Electro-Textile Antennas
Feiyuan Long and Xiao Dong Zhang (City University of Hong Kong, Hong Kong); Toni Björninen and Johanna Virkki (Tampere University, Finland); Lauri Sydänheimo (Tampere University of Technology, Finland); Chan Yan-Cheong (City University of Hong Kong, Hong Kong); Leena Ukkonen (Tampere University of Technology, Finland)
Sensing capabilities embedded in a passive UHF RFID tag provide a battery-free wireless sensor equipped with a digital identifier. We present an RFID strain sensor tag based on a stretchable antenna made of conductive fabrics. To create an efficient antenna for the sensor tag, we use non-stretchable and highly conductive copper-coated fabric to form the main antenna body and join a section of stretchable conductive fabric by means of sewing with conductive thread. We test wirelessly two different sensors with 1 cm and 3 cm stretchable sections and characterize them in terms of the maximal sensor readout distance and the response of its backscatter strength to the antenna elongation. Our results show that the percentage change in the backscatter strength is in approximately linear relation with the antenna elongation.
Influence of Phantom Models on Implantable Antenna Performance for Biomedical Applications
Neus Vidal, Aleix Garcia-Miquel, Josep Maria Lopez-Villegas and Javier Sieiro (University of Barcelona, Spain); Francisco Ramos (Francisco Albero S.A., Spain)
The performance variations of implantable antennas due to the influence of the phantom model dimensions, shape or the implant depth is reported in this paper. Three 2D-square spiral PIFA prototypes operating in the Medical Device Radiocommunications Service frequency band and in the Industrial Scientific and Medical bands are presented and characterized to assess the influence of the surrounding tissues in the radiation features. The electromagnetic modeling is based on the finite-difference time-domain method. The dielectric properties of the skin have been taken as a reference for the parameters of phantom models while the Low-Temperature Co-fired Ceramic technology has been chosen for the substrate. The results show that some antenna features such as the gain, the efficiency or the radiation pattern are substantially modified when changing phantom dimensions or implant depth. Finally, the standardization of implantable antenna characterization is suggested in order to improve the comparison between prototypes.
Miniaturization Effects on Implantable Antennas for Biomedical Applications
Aleix Garcia-Miquel, Neus Vidal, Josep Maria Lopez-Villegas and Javier Sieiro (University of Barcelona, Spain); Francisco Ramos (Francisco Albero S.A., Spain)
The study of the antenna performance for a square spiral PIFA miniaturization is presented in this report. The prototypes analyzed operate in the Medical Device Radiocommunications Service (MedRadio) frequency band (401-406 MHz). Three miniaturization techniques are compared to come out with the more suitable method in terms of efficiency and volume. The electromagnetic modeling is based on the finite-difference time-domain method. Low-Temperature Co-fired Ceramic technology is used for the substrate. Results indicate that the 3D structure with the radiator facing the ground plane achieves the best performance in a volume of 200 mm3 for a square spiral PIFA antenna.
Humidity Passive Sensors Based on UHF RFID Using Cork Dielectric Slabs
Ricardo Gonçalves (Instituto de Telecomunicações - Aveiro & Evoleo Technologies, Portugal); Pedro Pinho (IT - Instituto de Telecomunicações & ISEL - Instituto Superior de Engenharia de Lisboa, Portugal); Nuno Borges Carvalho (University of Aveiro/IT Aveiro, Portugal); Manos M. Tentzeris (Georgia Institute of Technology, USA)
In this paper we show the design of passive UHF RFID tag antenna on cork substrate. Due to the cork sensitivity to humidity changes, we can use the developed sensor to sense changes in the relative humidity of the environment, without the need for batteries. The antenna is built using inkjet printing technology, which allows a good accuracy of the design manufacturing. The sensor proved usable for humidity changes detection with a variation of threshold power from 11 to 15 dB between 60 and near 100% humidity levels. Presenting, therefore, reading ranges between 3 to 5 meters.
Antenna Q for Small Antennas with Radiation Constraints and Perturbations
Lars Jonsson (KTH Royal Institute of Technology, Sweden); Mats Gustafsson (Lund University, Sweden)
Lower bounds on antenna Q for small antennas have recently been formulated as an optimization problem. The approach includes antennas modeled with electric and magnetic currents. We show here that constraints on the direction of radiation can increase antenna Q. We also investigate what happens to antenna Q lower bounds for electric dipole antennas when the maximal radiation increases in the presence of a small superimposed magnetic dipole. Such radiation perturbations can be caused by feeding and in coupling between currents. Magnetic-dipole perturbation yields a new lower antenna Q bound, that is lower than the pure electric dipole bound on antenna Q.
Reducing and Controlling the Beamwidth of Electrically Small Antenna Arrays
Jingni Zhong (Ohio State University & ElectroScience Laboratary, USA); Asimina Kiourti (The Ohio State University, USA); John L. Volakis (Florida International University, USA)
As the size of wireless devices becomes smaller, there is a need for miniature arrays with narrow beamwidth. However these miniature arrays always have: (a) high reactive impedance, (b) strong inter-element coupling, and (c) wide beamwidth. In this work, we present an electrically small antenna array (λ/10 at 400MHz) that overcomes these challenges and achieves a half power beamwidth (HPBW) of 28o. Our approach uses a reactive line for matching, and employs a parasitic element to reduce coupling between the array radiators. Concurrently, a biomimetic circuit is used to amplify the phase difference between adjacent elements (as close as λ/20 apart) to reduce beamwidth. Beamwidth control is also demonstrated by tuning the phase amplification circuit.
Small UHF RFID Tag Antenna for Metallic Objects
Sergio López-Soriano and Josep Parrón (Universitat Autònoma de Barcelona, Spain)
Nowadays, the labeling of metal objects faces the challenge of getting a large read range while maintaining a reduced antenna size. This contribution presents a tag antenna design for identifying metal objects in the European UHF band (865-868 MHz). The antenna consists of a dipole mounted on a thin dielectric which is coupled to two shorted patches mounted on FR4 substrate. The overall dimensions of the tag are 73 mm x 25 mm x 3.2 mm. Full wave simulations show that this tag could attain a read range of 9.5 m when attached to a metal.
Use of the Characteristic Modes Theory for the Design of an Antenna in a Harsh Environment From a Generic Antenna Topology
Francois Gallée and Jean Philippe Coupez (Télécom Bretagne, France); Eva Antonino-Daviu (Universitat Politècnica de València, Spain); Marta Cabedo-Fabrés (Universidad Politécnica de Valencia, Spain); Thomas Bernabeu (Iteam Institute - Universitat Politècnica de Valencia, Spain); Alejandro Valero-Nogueira (Universidad Politécnica de Valencia, Spain)
In new applications: internet of thing, machine to machine wireless communication, wireless sensors network, the energy efficiency is important to move towards the energy autonomy. In sensor nodes, the main power consumption is the wireless communication system. The antenna performances (efficiency) will impact directly on it. That why, the antenna design is crucial. Furthermore, for many applications, the antenna environment is complex and the dimension and the distance of metallic (metallic box) or dielectric structure could be equal or inferior to the wavelength. To answer to this problematic, we propose a generic antenna topology and the use of a methodology based on the characteristic mode theory to adjust the resonant frequency in taking into account the closed metallic and dielectric environment
An Electrically Small Three-Band Multi-polarization Cross Spiral Antenna
Mayumi Matsunaga (Tokyo University Technology, Japan); Masataka Suzuki (Ehime University, Japan)
Electrically small three-band antennas that can simultaneously radiate circularly and linearly polarized waves are presented in this paper. The authors have invented Loop/Spiral antennas named Cross Spiral Antenna (CSA), which can radiate multi-polarized waves at multi-frequency with only one port feed. Reducing the size of CSA, while maintaining their performance, has been our highest aim in recent research. In this paper, adding fork-shape elements as one of the ways to shrink our CSA is suggested. This research focus successfully yielded an electrically small three-band multi-polarization CSA where the size is one tenth of a lowest utilizing wavelength square. The experimental antenna shown in this paper is tuned for RFID, GPS and a mobile phone band.
On the Extending Bandwidth of Electrically Small Antenna Using Negative Impedance Converter
Katarzyna Jagodzińska (Koszalin University of Technology, Poland)
This paper deals with extending bandwidth of electrically small antenna using negative impedance converter that acts as a negative reactance. Using the idea of negative impedance converter an active reactance circuit is proposed to cancel the imaginary part of electrically small antenna impedance and thus matched antenna to the transmitter over a wide band. Furthermore, design and measurement results of active reactance circuit are presented and discussed in details.
About Radiation Efficiency Optimizing of A Miniaturized Antennas
Yaakoub Dia (University of Limoges, France); Laure Huitema (Xlim Laboratory, France); Christophe Delaveaud (CEA-LETI, France); Stéphane Bila (XLIM UMR 7252 Université de Limoges/CNRS, France); Marc Thevenot (XLIM-UMR CNRS 7252, University of Limoges, France)
the miniaturization of a compact omnidirectional antenna while keeping a high radiation efficiency. More accurately, the structure of a monopolar wirepatch antenna is modified to optimize its radiation efficiency with a constant global dimension constraint. It is then shown that a lower operating frequency (1.8 GHz versus 2.5 GHz) can be obtained with very similar radiation efficiency but under different impedance locus. This means that the monopolar wire patch antenna developed on the optimal impedance presents the same radiation efficiency while having lower dimensions (compared to the free space operating wavelength). This technique studied by 3D electromagnetic simulation is then validated by the results obtained with a set of prototypes.
Modified Minkowski Fractal Patch Antenna for Multiband GPS Receiver
Wojciech Krzysztofik (Wroclaw University of Technology, Poland); Lukasz Nartowski (NOKIA Wroclaw, Poland)
The object of the study was the antenna of fractal geometry for GPS portable terminal. To make an objective assessment of the results obtained specified electrical network and field parameters of designed antennas. The focus was directed toward tuning the resonant GPS frequency position by means of modification of Minkowski curve geometry. The theoretical analysis, design procedures, as well as the experimental results confirms each other in good agreement.
A Preliminary Study on a Reduced Size Planar Grid Array for Automotive Radars
Emilio Arnieri (University of Calabria, Italy); Amedeo Michelin Salomon (STMicroelectronics, Catania, Italy); G. Amendola (Universita della Calabria, Italy); Luigi Boccia (University of Calabria, Italy); Mario Paparo (STMicroelectronics, Catania- Italy, Italy); Salvo Scaccianoce (STMicroelectronics, Catania, Italy)
A reduced size planar grid array antenna for automotive radar sensor applications operating in the 77-81 GHz frequency band is introduced. Antennas for this type of application must be low in cost to manufacture and as small as possible. Proposed antenna consists of reduced size loop elements. Planar differential microstrip line is used to feed the central element. The single row offers a narrow beam in elevation and a wide beam in azimuth. Compared to other automotive radar configurations, this antenna design is a completely planar antenna based on a low-cost fabrication technology. A size reduction of 55% has been achieved.
Human Effect on Twin Antenna On-body for Three Diversity Techniques At 2.4 GHz
Dina Al-Saffar, Robert Michael Edwards, Oluwaseun A Ojerinde, Chinthana J Panagamuwa and Rob Seager (Loughborough University, United Kingdom (Great Britain))
Since the user is generally in the near field On-body antennas are accepted as more complex to optimise than their free space counterparts. Use of the body as a platform for wearable electronics is a topical subject. Omnidirectional antennas are thought to be useful for antennas in body area networks. However, the desirable properties of omnidirectional radiation patterns close to humans are severely diminished due to the lossy load nature of biological matter and high levels of scattering due to shadowing and mismatch. To alleviate these problems two or more antennas can be used on the body. In this paper, two on body antennas are used with different combination techniques in order to evaluate the diversity performance and then compared with their free space equivalents. Three diversity techniques are used – Selective, maximal ratio and equal gain. The frequency of operation was 2.4GHz.
Performance on the Human Body of a Dual-Band Textile Antenna Loaded with Metamaterials
Sen Yan (Xi'an Jiaotong University, China); Ping Jack Soh (Universiti Malaysia Perlis); Guy Vandenbosch (Katholieke Universiteit Leuven (KU Leuven), Belgium)
A dual-band textile antenna loaded with metamaterials is proposed and analyzed. By introducing a composite right/left-handed transmission line, similar field distributions and radiation patterns are obtained in the two operation bands. The antenna is calculated on a human tissue model for both planar and bending situations. The antenna performance, e.g. resonant frequency, impedance matching bandwidth, directivity, gain, radiation efficiency, and specific absorption ratio (SAR), are compared. This verifies the antenna robustness and safety for use on a human body.
Knitted Textile Waveguide Bending
Xiaobin Jia (The University of Sheffield, United Kingdom (Great Britain)); Alan Tennant and Richard Langley (University of Sheffield, United Kingdom (Great Britain)); Tilak Dias and William Hurley (Nottingham Trent University, United Kingdom (Great Britain))
This paper presents the performance of a knitted textile waveguide under different bending conditions. The waveguide is designed to operate at X-band and consists of a textile sleeve and knitted polyester inside. S21 of the bent knitted waveguide is compared to that of the straight knitted waveguide in both simulation and measurement.
Dually Polarized Tunable Printed Antennas for Medical Applications
Albert Sabban (Kinneret and ORT BRAUDE COLLEGE, Israel)
Biomedical industry is in continuous growth in the last decade. Low profile compact tunable antennas are crucial in the development of wearable human biomedical systems. The antenna resonant frequency may be tuned by using a varactor to compensate variations in antenna resonant frequency at different locations on the body. Design considerations, computed and measured results on the human body of wideband printed antennas with high efficiency at 434MHz are presented in this paper. The proposed antenna may be used in Medicare systems.
Sensitivity of a Wearable Printed Antenna with a Full Ground Plane in Close Proximity to Human Arm
Syed Muzahir Abbas and Yogesh Ranga (Macquarie University, Australia); Karu Esselle (University of Technology Sydney, Australia)
This paper presents sensitivity analysis of a printed antenna with a full ground plane, suitable for wearable armbands and other such body area network devices operating in the industrial, scientific, and medical (ISM) band (2.45 GHz). Antenna input impedance and radiation characteristics are presented along with the parametric analyses. Antenna performance is investigated in free space and in close proximity to various human arm models (i.e. flat, rectangular and elliptical). The full ground plane makes the antenna highly insensitive to the gap between the antenna and the arm in addition to reducing electromagnetic radiation absorption in the arm. Small width (14mm) of the antenna makes it feasible to position along the length of a human arm without bending, which causes shift in resonant frequency.
Design and Analysis of a Wearable Antenna System for Wireless Safety Applications
Mahmoud Ali (University of Siena, Italy); Guido Biffi Gentili (University of Florence, Italy); Claudio Salvador (Advanced Microwave Engineering, Italy); Alberto Toccafondi (University of Siena, Italy); Filippo Zani (Advanced Microwave Engineering, Italy)
In this paper, a wearable antenna system is designed and integrated into cloths and shoes for communication purposes such as safety and tracking activities. The radiating characteristics are evaluated for different positions on a sample shoe using a detailed simulation model with a homogeneous foot phantom. The performance of the communication link between transmitting and receiving antenna is analyzed by investigating the antenna pattern in far field at 2.45 GHz.
Performance of Embroidered Conductive Yarn in Textile Antennas and Microstrip Lines
Branimir Ivšić (Ericsson Nikola Tesla d. d. & University of Zagreb, Faculty of Electrical Engineering and Computing, Croatia); Davor Bonefačić (University of Zagreb, Faculty of Electrical Engineering and Computing, Croatia); Juraj Bartolić (University of Zagreb, Croatia)
The influence of mechanical factors onto conductivity of the conductive yarn is studied. Several microstrip lines with various thread tensions are manufactured and compared in performance, to propose the strategy for efficient design and implementation of conductive textiles.
Investigation of Textile Striplines Connectivity for Feeding and Connecting Wearable Antennas
Aris Tsolis and Antonis A Alexandridis (NCSR Demokritos, Greece); William Whittow and J (Yiannis) Vardaxoglou (Loughborough University, United Kingdom (Great Britain))
This paper presents alternative methods for connecting parts of textile stripline transmission lines. The proposed scenarios for striplines connection exclude completely the use of coaxial connector (e.g. SMA). This makes them more appropriate for wearable applications requiring flexible interconnections between wearable antennas and electronics.
Microwave Interconnects Between Textile and Rigid Substrates Using Permanent Magnets
Duarte de Sousa Fonseca, Rob Seager and James A. Flint (Loughborough University, United Kingdom (Great Britain))
This paper presents a new approach to the problem of the transition between a textile microwave system and a regular microwave system. A simulated model of a transition between copper conductive line and textile conductive line is presented, with a comparison between simulated and measured results of the same model showing close proximity. The work aims to create a full textile remountable and flexible microwave connector.
Effect of Ink Usage Conservation Techniques on the Read Range of Inkjet Printed Epidermal RFID Tags
Dumtoochukwu Oyeka (University of Kent., United Kingdom (Great Britain)); John Batchelor (University of Kent, United Kingdom (Great Britain))
The effect of reducing the volume of conductive ink used in the fabrication of Epidermal RFID tags on the read range of the tag is investigated in this paper. The ink usage reduction is achieved by trimming the conductive parts of the designed tag.
The Analysis of Influence of Textile Antenna Location on Its Performance
Lukasz Januszkiewicz (Lodz University of Technology, Institute of Electronics, Poland)
In the paper the analysis of the influence of textile antenna location on its radiation pattern is presented. The analysis is based on a textile vee- type antenna proposed by the author. The antenna radiation pattern for on body location is examined with computer simulations in XFdtd program. The computer simulation results are then verified with measurements. Performance of the textile antenna is compared with performance of a standard dipole antenna.
Vertically Polarized Omnidirectional Printed Slot Loop Antenna
Nikolaj P. B. Kammersgaard and Søren H Kvist (Technical University of Denmark & GN ReSound A/S, Denmark); Jesper Thaysen (GN ReSound A/S, Denmark); Kaj Bjarne Jakobsen (Technical University of Denmark, Denmark)
A novel vertically polarized omnidirectional printed slot loop antenna has been designed and simulated. The slot loop works as a magnetic loop. The loop is loaded with inductors to insure uniform and in-phase fields in the slot which gives the omnidirectional radiation pattern. The antenna could have many applications, but because of the polarization it is ideal for launching on-body creeping waves.
Investigation of Candidate Antennas for Body Area Networks: Characterization in the Proximity of Human Tissues
Jian Wang and Milica Popović (McGill University, Canada)
In this work, we focus on ceramic antenna properties in the vicinity of the human tissues, motivated by their potential usage in body area network (BAN) applications. We first investigate a commercially-available ceramic antenna in controlled experiments using tissue-mimicking phantoms. Second, we propose an alternative ceramic antenna deign for the 3-10 GHz range, and show the preliminary results of its properties near body tissues obtained through simulation. We find that the antenna performance will vary significantly with relatively small increase of distance from the tissue surface (skin); hence, careful consideration needs to be given to proper placement and robustness of antennas intended for BANs.
Wireless Power Transfer Using Self-resonant Spiral Antenna Through Reinforced Plasterboard Wall
Feasibility of wireless power transfer via a wall made of a steel-reinforced plasterboard is demonstrated by MoM simulation and experiment. We have found that the transmission efficiency is improved by adjusting the space between the antenna and the wall because influence of permittivity of the wall is reduced.
Circular-Polarization Reconfigurable Monopole Antenna with Enhanced Boresight Gain for GNSS Applications
Yunfei Cao (South China University of Technology, China); William S. W. Cheung and Ti Yuk (The University of Hong Kong, Hong Kong)
A circular-polarization (CP) reconfigurable monopole antenna with enhanced boresight-gain for GNSS applications is presented. The antenna consists of two meandered monopoles placed perpendicular to each other, a feeding network using the Wilkinson power divider, two switchable 900-phase-shifters, a defected ground structure (DGS) and a metallic reflector. The input signal is divided into two signals with equal amplitude and phase by the power divider and fed to the meandered monopoles via the phase-shifters. The two signals arrived at the two monopoles have a phase difference of 900 or -900, depending on the phase-shifters controlled by six PIN-diode-switches, hence generating a right- or left-handed CP signal. The metallic reflector is placed at the back of the antenna to improve the efficiency and boresight gain. Simulation results show that the reflector can substantially increase the boresight-gain and efficiency of the antenna in the operating band, yet retaining the impedance-bandwidth and axial-ratio-bandwidth.
Antenna with Patterns and Polarizations Dual Controlling Freedom
Haitao Liu (China Academy of Space Technology, China); Tian Hong Loh (UK, National Physical Laboratory, United Kingdom (Great Britain)); Steven Gao (University of Kent, United Kingdom (Great Britain))
This paper presents a polarization reconfigurable smart antenna with electronically switchable radiation patterns. The smart antenna can be dynamically altered to achieve vertical linear, horizontal linear or diagonally linear polarization. The radiation pattern switching is achieved by the electronically reconfigurable parasitic radiators, which are closely placed around the patch antenna. In this configuration, the polarization-reconfigurable patch antenna is used as the driven element. The parasitic radiator is composed of a printed dipole with a PIN diode in the middle soldered in series. By switching the bias voltage over the PIN diode, the parasitic element can be electronically reconfigured as a reflector or a director. Thus the radiation pattern can be switched. With its reconfigurable polarization and switchable radiation pattern, this antenna is suitable for conquering the multipath fading effects encountered in modern wireless communication systems. Further, this antenna suggests a low cost solution for generating the electromagnetic vortex
Experimental Validation of an Agile Electromagnetic Band Gap Matrix Antenna
Hussein Abou Taam (University of Limoges & XLIM, France); Georges Zakka El Nashef and Eric Arnaud (XLIM, France); Thierry Monediere (University of Limoges & CNRS, France); Bernard Jecko (XLIM, France); Mohamed Rammal (Lebanese University, Lebanon)
This paper presents an experimental validation of a novel antenna system called "electromagnetic band gap matrix antenna". The theoretical concept is based on the equivalent radiating surface approach and the antenna design is inspired from the electromagnetic band gap antennas. In this paper, an experimental validation is demonstrated to validate the theoretical concept of the antenna and several electromagnetic performances such as the low mutual coupling and the beam steering.
A Developed Excitation Law for Beam Forming and Steering Applied to A Novel Electromagnetic Band Gap Antenna
Hussein Abou Taam (University of Limoges & XLIM, France); Georges Zakka El Nashef and Eric Arnaud (XLIM, France); Thierry Monediere (University of Limoges & CNRS, France); Bernard Jecko (XLIM, France); Mohamed Rammal (Lebanese University, Lebanon)
This paper presents an experimental validation of a developed feeding technique applied to a novel antenna system called electromagnetic band gap matrix antenna. The experimental validation will not only demonstrate the theoretical concept of the antenna, but it will also show the efficiency of applying a developed excitation law which enables us to obtain a sectorial radiation pattern presenting a quasi-constant gain over an angular range of 18° with low side lobes level less than -20 dB. The feeding technique process is described in this paper and some experimental results are presented to demonstrate the beam forming and steering capabilities of the matrix antenna.
Comparison Between Pneumatically-Controlled and PIN-Diode-Based Aperture-Coupled Patch Antennas
Billy Wu (University of Calgary, Canada); Michal Okoniewski (University of Calgary & Acceleware Ltd, Canada); Chris Hayden (University of Calgary, Canada)
The operation of a frequency-switchable aperture-coupled patch antenna is described. The selection of one of two orthogonal slots on the ground plane dictates which dimension of the rectangular patch is excited and hence the resonant frequency of the antenna. The slot selection can be controlled by either a pneumatically-operated copper-backed swinging arm or DC-biased PIN diodes. The simulated RF performance of both designs was compared.
A Reconfigurable Patch Antenna with Symmetrical Structure for Polarization Diversity
Sung Woo Lee and Young Je Sung (Kyonggi University, Korea (South)); Seung jae Lee, Ho sang Yoon and Hong joon Park (HCT, Korea (South))
A reconfigurable patch antenna with symmetrical structure for polarization diversity is proposed in this article. The proposed antenna mainly consists of a rhombus-shaped patch with single feed, two conductive pads with via hole and two PIN diodes. The antenna can produce right-hand circular polarization (RHCP) and left-hand circular polarization (LHCP) by adjusting bias state of two PIN diodes. The fabricated antenna satisfies a 10-dB bandwidth of 100 MHz in the RHCP and LHCP as well as it has -3dB axial ratio bandwidth of 55 MHz.
A Reconfigurable Beam-Scanning Partially Reflective Surface (PRS) Antenna
Lu-Yang Ji (Northwestern Polytechnical University, China); Y. Jay Guo (University of Technology Sydney, Australia); Peiyuan Qin (University of Technology, Sydney, Australia); Guang Fu (Xidian University, China)
A novel reconfigurable partially reflective surface (PRS) antenna is presented in this paper. The beam scanning ability is realized by employing a reconfigurable PRS structure and a phased array as the source. The design achieves a beam switching between-15°, 0°, to 15° with respect to the broadside direction from 5.5 GHz to 5.7 GHz with the realized gains over 12 dBi. Good agreement between the simulated and measured results is achieved.
Antenna System for Temperature Sensing
Mathieu Cosker (Université côte d'Azur, CNRS, LEAT, France); Robert Staraj (University Cote d'Azur, CNRS, LEAT, France); Jean-Marc Ribero (Université de Nice Sophia Antipolis, France)
This paper presents an antenna with sensing capabilities using shift frequency to determine the temperature. This antenna is made up of a dipole operating at 1.5 GHz and a mercury thermometer operating between 10 and 53 degree Celsius. The dipole is used to excite the thermometer as an equivalent metallic dipole by coupling. The changes in physical dimensions of the mercury dipole due to temperature changing involve a frequency shift of the resonant frequency. The measured results show this frequency variation as a function of the temperature.
Reconfigurable THz Metamaterial Antenna Based on Graphene
Ahmed Radwan (Politecnico di Milano, Italy)
The adoption of metamaterials in the development of terahertz (THz) antennas has led to tremendous progresses in the THz field. In this paper, a reconfigurable THz patch antenna based on graphene is presented, whose resonance frequency can be changed depending on the applied voltage. By using an array of split ring resonators (SRR) also made of graphene, both bandwidth and radiation properties are enhanced; it is found that both the resonance frequency and bandwidth change with the applied voltage.
Low-Profile Compact-Size Electronically Beam-Switching Antenna for Wireless Communications
Long Zhang and Steven Gao (University of Kent, United Kingdom (Great Britain)); Qi Luo (University of Herfordshire, United Kingdom (Great Britain))
This paper proposes a novel compact-size low-profile low-cost smart antenna which could electronically switch the beam. Through DC control of the on/off status of four embedded PIN diodes sequentially, the proposed antenna can switch its beam in sequence covering the full range of 360 degree in the azimuth plane. It is shown that a minimum 22% bandwidth and 3 dBi peak gain can be achieved whatever the states of the four PIN diodes are. Meanwhile, over 15 dB front to back ratio (FBR) can be obtained as well, which indicates that this antenna is suitable for anti-interference application in multi-path fading environments such as the wireless communication scenario. Compared to other low-cost smart antennas reported, the height of this antenna is much reduced and its advantages include low profile, compact size, planar structure, low cost and the capability of covering the full range of 360 degree in the azimuth plane.
Pattern Reconfigurable Wideband Circularly-Polarized Quadrifilar Helix with Broadside and Backfire Radiation Patterns
Wei Lin (University of Technology Sydney, Australia); Hang Wong (City University of Hong Kong, Hong Kong)
This paper introduces a pattern reconfigurable wideband circularly-polarized (CP) quadrifilar helical antenna (QHA) with both broadside and backfire radiation modes. A compact 1:4 power divider network is proposed to feed the QHA for obtaining the wide bandwidth. To realize pattern diversity, PIN diodes on the power divider are to reconfigure the phase outputs such that the direction of radiation pattern can be controlled alternatively for the broadside or the backfire radiation. The pattern reconfigurable QHA has the wide impedance bandwidth of 35% and the wide 3-dB AR bandwidth of 41%. Both broadside and backfire radiations have similar pattern shape with the 3-dB beamwidth of 130 degree. The proposed antenna can be used in many applications as subway and railway communications, base station for narrow street coverage, RFID or satellite systems.
Mutual Coupling Control in a Multiple Antenna System Using Ferrimagnetic Substrate
Evmorfili Andreou (NCSR Demokritos & National Technical University of Athens, Greece); Theodore Zervos (NCSR "Demokritos", Institute of Informatics & Telecommunications, Greece); Antonis A Alexandridis (NCSR Demokritos, Greece); Fotis Lazarakis (NCSR Demokritos, Institute of Informatics & Telecommunications, Greece); George Fikioris (National Technical University of Athens, Greece)
In this paper, we present the design of a printed multiple antenna system that uses a ferrimagnetic compound (YIG) as part of the substrate. We investigate the influence of this material on the mutual coupling between the antenna elements when an external magnetic field is applied. It is proved that the proper application of the magnetic field changes the polarization of the elements from linear to circular and additionally reduces their mutual coupling.
Reconfigurable PIFA Antenna Using RF MEMS Switches
Ghassen Chaabane (XLIM Université de Limoges, France); Pierre Blondy (XLIM – University of Limoges, France); Matthieu Chatras (XLIM - Université de Limoges, UMR CNRS, France); Cyril Guines and Valerie Madrangeas (XLIM – Université de Limoges, UMR CNRS, France)
This paper presents the simulations, fabrication and measurement of a tunable planar inverted-F antenna (PIFA). The antenna is made with three patches, connected and disconnected with RF-MEMS switches. Measurements show a tuning range from 1.4 GHz to 1.1 GHz depending on the switch state. The tunable antenna has a good matching better than 9.5 dB.
A Tunable Filtenna for Cognitive Radio Applications
Ali Ramadan (Fahad Bin Sultan University, Saudi Arabia); Karim Youssef Kabalan, Joseph Costantine and Youssef Tawk (American University of Beirut, Lebanon); Christos Christodoulou (University of New Mexico, USA)
In this paper, a varactor-tuned filter-antenna (filtenna), for cognitive radio applications is proposed. The presented technique is based on electronically tuning the resonant frequency of a compact tunable band-pass filter, which is integrated into a wideband antenna. The change in the loading capacitance of the installed varactor results in frequency tuning of the whole filtenna system, while preserving its radiation characteristics.
Reconfigurable Square Patch Antenna Using Capacitive Loading and Varactor Diode
Ines Rouissi (FACULTE DES SCIENCES DE TUNIS, Tunisia); Jean-marie Floch (IETR-INSA Rennes, France); Hatem Rmili (King Abdulaziz University & Faculty of Engineering, Saudi Arabia); Hichem Trabelsi (Faculte des Sciences de Tunis, Tunisia)
This paper presents a frequency reconfigurable antenna with varactor diode. The antenna adapted to operate at 2.45 GHz consists of square patch excited by a coaxial probe. The frequency agility was achieved by integrating a varactor diode between the patch and the ground plane, which reduces the size of the antenna. A high tuning range of 2.43 to 0.5 GHz is realized for a varactor biasing voltage varying from 0 to 20 V. The experiments was performed, for both cases; using a chip capacitor then using a varactor diode.
A New High-Gain and Low-Complexity Pattern-Reconfigurable Antenna
Stylianos D. Assimonis (Queen's University Belfast, United Kingdom (Great Britain)); Argiris Theopoulos and Theodoros Samaras (Aristotle University of Thessaloniki, Greece)
A new pattern-reconfigurable antenna, which operates from 2.36 GHz to 2.55 GHz and has maximum gain 7 dB at horizontal plane, is presented in this work. In contrast to prior art designs, there is no ground plane, which usually displaces the gain main lobe from the horizontal plane. In this paper, the mainlobe elevation angle is zero. Analytically, it is an Electronically Steerable Parasitic Array Radiator (ESPAR) antenna, based on Yagi-Uda antenna concept, and utilizes printed elements on low-cost FR-4: a bow-tie dipole (driven-element) was surrounded by eight bow-tie parasitic-elements. The latter, which can be open or short -circuited using voltage-control switchers, act as directors or reflectors and hence accurately control the radiation pattern. The antenna was analyzed in terms of reflection coefficient and realized gain and finally was fabricated and measured. Measurements agree well with simulations.
Compact Frequency Reconfigurable Slot Antenna with Continuous Tuning Range for Cognitive Radios
William S. W. Cheung (The University of Hong Kong, Hong Kong); Yunfei Cao (South China University of Technology, China); Ti Yuk (The University of Hong Kong, Hong Kong)
The design of a compact frequency-reconfigurable slot antenna for cognitive radios is proposed in this paper. The antenna consists of a rectangular-ring slot, a T-shaped feed line, an inverted T-shaped stub and two varactors. The length of the rectangular-ring slot is designed to resonate at about 2.4 GHz. The inverted T-shaped stub is used to extend the current path, making the total size of the antenna smaller for low frequency operation. The two varactors are used to achieve continuous tuning. The proposed antenna is studied and designed using computer simulation. The simulated return loss, radiation pattern, realized peak gain and efficiency of the antenna are presented. Results show that the antenna has a wide tuning range from 2.14 to 3.33 GHz (43.51%) and is a potential candidate for use in cognitive radios.

Poster A4: Antennas Poster Session 4

Room: Luís de Camões (Hall 3)
Chairs: Enrique González-Plaza (Universidad de Oviedo, Spain), Hamed Hasani (Ecole Polytechnique Fédérale de Lausanne, Switzerland)
Synthesis of Timed Antenna Arrays for Arbitrary Shaped-Beam Energy Patterns
Alberto Reyna (Autonomous University of Tamaulipas, Mexico); Marco Panduro (Autonomous University of Tamaulipas); Carlos del-Río (Universidad Publica de Navarra & Institute of Smart Cities, Spain)
this paper presents a new research in the field of timed antenna arrays. The study proposes the synthesis of timed antenna array for arbitrary shaped beam energy patterns. The synthesis is formulated as an optimization of the true-time delays and amplitude coefficients in order to obtain a desired mask and low side lobes. The optimization is by using the well-known particle swarm optimization. The simulation results show the performance of timed antenna arrays to provide accurate arbitrary shaped beam energy patterns.
Development of Odd Orientation Array Antenna (OOAA) by Using Leucaena Leucocephala Substrate
Ahmad Azlan Ab Aziz (Politeknik Sultan Salahuddin Abdul Aziz Shah, Malaysia); Mohd Tarmizi Ali (Universiti Teknologi Mara, Malaysia); Faizal Jamlos (Universiti Malaysia Perlis, Malaysia); Zaiki Awang (Universiti Teknologi MARA, Malaysia)
The research paper covered the 3 by 3 odd orientation array antenna (OOAA) design and fabrication by using Leucaena leucochephala bio-composite substrate material. The objective of the paper was to utilize and design off centred orientation feed array antenna onto the bio-composite substrate with the mixture of 70% stem wood Leucaena leucochephala at 40 mesh and 30% of polypropylene polymer act as laminator and noted as PB7030 substrate. The PB7030 reported constant on all it dielectric constant (εr = 3.02) and loss Tangent (Tan δ = 0.082) value with target frequency of 2.45GHz (antenna design frequency). All result obtained will be analysed and displayed in the form of data and graph.
An Electronically Controlled 8-Element Switched Beam Planar Array
Sameir Deif (Donadeo Innovation Centre for Engineering & University of Ablerta, Canada); Saeed Dweik (KFUPM, Saudi Arabia); Mohammad S. Sharawi (Polytechnique Montreal, Canada)
An 8-element planar antenna array with electronically controlled switchable-beam pattern is proposed. The planar antenna array consists of patch elements and operates in the 2.45 GHz. The array is integrated with a digitally controlled feed network that provides the required phases to generate 8-fixed beams covering most of the upper hemisphere of the array. Only a 3-bit digital word is required for the generation of the 8-different beams. The integrated array is designed on a 3-layer PCB on a Taconic substrate (RF60A). The total dimensions of the fabricated array are 187.1 x 261.3 x 1.3 mm3.
A Planar Ku Band Antenna for Satellite Communications
Mesut Gokten, Ahmet F Yagli and Lokman Kuzu (Turksat International Satellite and Cable Operator, Turkey); Senol Gulgonul (Turksat International Satellite and Cable Operator & Turksat Satellite Communication and Cable TV AS, Turkey)
In this study a planar Ku band antenna is designed and built for satellite communications especially to receive TV signals in Turkey. This paper summarizes the design, manufacturing and test phases of the study and demonstrates the measurement results of the prototype antenna.
Broadband Focusing Using Aperture-Coupled Microstrip Patch Antenna Arrays
Randy L. Haupt, Atef Elsherbeni and Payam Nayeri (Colorado School of Mines, USA)
A new design for a broadband focused planar array using aperture-coupled stacked patches is presented. The array has a Dolph-Tschebyscheff amplitude taper. Mutual coupling is compensated by using the active scattering matrix. A 4×4 focused planar array antenna having a bandwidth of 26.5% is demonstrated.
Two- And Three- Dimensional Near Field Beam Steering Loop Arrays
Bo-Hee Choi, Byung-Chul Park and Jeong Hae Lee (Hongik University, Korea (South))
This paper presents near field beam steering arrays for wireless power transfer. Two types of near field beam steering arrays are introduced. One is two-dimensional array; the near field power is steered to a specific position of a receiver whose separation is 50 cm from the array at the frequency of 6.78MHz. The other is three-dimensional array which is composed of mode reconfigurable resonators insensitive to its alignment; the WPT efficiency in the azimuthal plane is measured at the transmitting distance of 20 cm at the frequency of 13.56MHz. Near field beam steering is achieved by controlling each capacitance of array resonator in both cases. The experimental results agree with the theoretical results.
An Air-filled Cavity-backed 2×2 Slot Sub-array Fed by Inverted Microstrip Gap Waveguide
Seyed Ali Razavi (Graduate University of Advanced Technology, Kerman, Iran); Per-Simon Kildal (Chalmers University of Technology, Sweden)
A wideband 2×2-slot element for a 60 GHz antenna array is designed by making use of air filled cavity fed by inverted microstrip gap waveguide. The designed element is a triple layer structure in which the upper layer contains four radiating slots backed by an air-filled cavity. The cavity is excited by a coupling slot fed by an inverted microstrip gap waveguide formed in the air-gap between the middle and lower layers. The designed 2×2-slot element is considered in an infinite array environment. A sample 32×32 slot array aperture is simulated using infinite array approach. The results show that the mismatch is better than -15 dB and the directivity larger than 38 dBi over 56.3-67.9GHz frequency range, i.e. 20.7 % bandwidth.
Extremely Low-Profile Planar Antenna Array for Satellite Communications in the Ku-Band
Ignacio Montesinos-Ortego, Ana Rosa Ruiz and Manuel J Gonzalez (TTI, Spain); Erika Méndez, Andrés Peñafiel, Alberto Chico and Iván Cayón (TTI Norte, Spain); Alberto Pellón (Celestia Technology Group UK, United Kingdom (Great Britain))
A really low-profile antenna system with excellent efficiency figures working in the Ku-band has been designed, manufactured and tested. Measurements of the prototype reveal excellent behavior in terms of radiation pattern and return loss. This paper presents a general overview of the array structure and its electrical performance with real measurements
Low Profile Array With Integrated High Impedance Surfaces For High Performance Adaptive GNSS
Cedric Martel (ONERA, France)
A compact and low profile array with integrated high impedance surfaces (HIS) is proposed in this paper. The array is comprised of 4 radiating cavities spaced 0.6 wavelength apart (center to center) and filled with dielectric material and two stacked patches. The HIS, which is made of a cavity and a FSS layer, is integrated between the radiating elements and minimizes the inter-element coupling. The presence of the HIS provides inter-element coupling levels below -30 dB. The coupling levels are -16 dB without HIS. The low inter-element coupling and low profile features of the antenna make the array an attractive solution for anti-jam adaptive GNSS applications.
A Parasitic Three-Element Superdirective Electrically Small Antenna Array
Abdullah Haskou (InterDigital, Inc., France); Antonio Clemente (CEA-LETI Minatec, France); Ala Sharaiha (Université de Rennes 1 & IETR, France); Christophe Delaveaud (CEA-LETI, France); Sylvain Collardey (University of Rennes 1, France); Lionel Rudant (CEA-Leti, France)
This paper presents a parasitic three-element superdirective electrically small antenna array based on very small printed loop antenna (unit-element). The unit-element dimensions are 24*20mm2 corresponding to λ/14*λ/17 relative to its resonance frequency of 900MHz. The array has been designed for an inter-element distance of 21.5mm. Its total dimensions are 63*24mm2, and it presents a simulated directivity of 9dBi. The array optimization has been performed using an ad-hoc procedure based on spherical wave expansion.
On the Simultaneous Mutual-Coupling Compensation for All the Space Directions
Jesús Rubio (University of Extremadura, Spain); Juan F. Izquierdo (Universidad de Extremadura, Spain); Juan Córcoles (Universidad Autónoma de Madrid, Spain)
A general method to obtain a matrix which allows the compensation of mutual coupling effects in transmitting arrays for the total field in all directions is introduced. This method is independent of the numerical method used in the analysis. The starting point can be the active element patterns or the spherical mode expansion from spherical near-field antenna measurements. Thus, active element patterns and isolated element patterns are used to find the mutual coupling compensation matrix. This way, it can be used with any kind of array and it can include the antenna platform. An advantage of this method is that it does not require an specific full-wave analysis method and any commercial software can be used. Through this method, which is completely general, it can be shown the limitation of the compensation capabilities as far as the array element is no longer a monomode antenna.
Interleaved Dual-band Circularly Polarized Active Array Antenna for Satellite Communications
Qi Luo (University of Herfordshire, United Kingdom (Great Britain)); Long Zhang and Steven Gao (University of Kent, United Kingdom (Great Britain)); Sergio Pires (Ampleon Netherlands BV, The Netherlands); Pedro Cruz (CONTROLAR SA, Portugal); Nuno Borges Carvalho (University of Aveiro/IT Aveiro, Portugal)
This paper describes a novel interleaved circularly polarized active array antenna for satellite communication applications at X-band. The array consists of two equilateral triangular patch arrays with hexagonal lattice, and each of them operates at different frequency bands. This presented interleaved array antenna can operate at dual frequency bands with independently beam steering capability when incorporated with phase shifters and MMICs, thus suitable for simultaneously transmitting or receiving in both user and feeder links for satellite on-board applications. The incorporation of MMIC GaN based high power amplifier in each radiating element is planned, to obtain high radiated power level by the multi-pixel active array antenna. Preliminary results on the X-band GaN power amplifier are also presented in this paper.
Fundamental Challenges for Wideband Antenna Elements in Focal-Plane Arrays