What's next in aeronautic connectivity and sensing?

Since the graphene discovery, its applications to electronic and optoelectronic devices have been intensively and thoroughly researched. The extraordinary and unusual electronic and optical properties allow graphene and other two-dimensional (2D) materials to be promising candidates for infrared (IR) and terahertz (THz) photodetectors. Quantity of published papers devoted 2D materials as sensors is huge. However, authors of these papers address them mainly to researches involved in investigations of 2D materials. Up till now, the first test to estimate their place in wide infrared detector family was given in Advances in Optics and Photonics 11(2), 314 379, 2019. In the present paper this topic is treated comprehensively with including both theoretical estimations and many experimental data. In the paper, at the beginning we describe shortly fundamental properties of graphene-based materials and alternative 2D materials, and performance of detectors fabricated with them. Next, the position of 2D material detectors is considered in confrontation with the present stage of infrared and terahertz detectors offered on global market. A new benchmark, so-called "Rule 19", used for prediction of background limited HgCdTe photodiodes operated near room temperature, is introduced. This rule is next treated as the reference for alternative 2D material technologies. The performance comparison concerns the detector responsivty, detectivity and response time. Final conclusions predicts place of 2D material-based detectors in the near future, in wide IR detector family.

PL612, one of the three Polish LOFAR stations is fully operational in the International LOFAR Telescope (ILT) since beginning of 2016. In second half of 2016 we have also started a pulsar observational projects in the local mode using the bałdy LOFAR station. In this paper we shortly describe a new project which focuses on the simultaneous observation of pulsars and the TEC parameter towards them in the sky.

We present a few examples of the type III solar radio bursts observed on 25th August 2017 with LOFAR (LOw-Frequency Array) station in Baldy, Poland. This station recorded the solar dynamic spectra in the frequency range from 10 MHz up to 250 MHz. The time and frequency resolution of the spectra were 1 s and 0.39 MHz respectively. The preliminary analysis of these radio events indicate that observations with use of the Baldy LOFAR station, in single mode, can give a lot of interesting results.

The development and the current state of the LOFAR-Latvia station is described. The proposed research is presented in the context of both the surrounding infrastructure of Ventspils International Radio Astronomy Centre (VIRAC) and of the established research directions with the focus on the field of solar and heliospheric physics.

In this paper we present the current status of the pulsar observations conduct by Polish LOFAR stations. In particular we show that the single LOFAR station can provide observations that are of sufficient quality to provide useful scientific data. These can help us to better understand some of the phenomena related to the pulsar emission and the influence of the interstellar matter.

In this work, the authors focused on assessing the reliability of the dense wireless network that draws inspiration from the human nervous system. The concept of such a network was created using the action of a glial cell, i.e. microglia, which is involved in the damaged nerve connections repair process. To assess reliability, the authors used the percolation theory, in particular the percolation threshold. This approach makes the results of simulations independent of the specific network topology. In the simulations carried out, the reliability level of the analyzed systems were also appointed.

The problem of waveforms constructing for mobile ad hoc networks with cognitive radio (MANET-CR) is discussed. This is one of the main questions limiting widely use this very attractive technique, that not need deployment of expensive communication infrastructure. The paper presents the structure of CR nodes with complex management procedures, using advanced Dynamic Spectrum Management together with the concept of policy-based radio. Here, the basic policy is to avoid interference generated by other users or interfering devices. The experiments were performed in a real environment, using the elaborated testbed. The results show that the use of sensing and cognitive management mechanisms enables more efficient use of the spectrum while maintaining reasonable overhead values related to the management procedures

This paper presents an efficient method of cooperative spectrum sensing for mobile radio networks with the hierarchical management structure. The network is divided into clusters controlled by cluster heads. All cluster members perform spectrum sensing using energy detectors. Sensing results are then transmitted to fusion centers in cluster heads, where they are combined using evidence theory based on Dempster-Shafer theory. The achieved simulation results show that the proposed method outperforms commonly used rules and gives a high probability of proper signal detection and low probability of false alarms.

This paper presents advantages of the machine learning used for estimation of specific radio channel usefulness, necessary for dynamic spectrum access. This method enables more efficient use of spectral resources, that are temporarily not used by licensed users. It indicates which channels are the most useful, i.e. give the highest probability of successful transmission and avoidance of interferences. Profile of Q-learning algorithm operation may be controlled by adaptation of the learning rate and greedy parameter

The purpose of this work was to create a wireless Internet-of-Things (IoT) communication module for a device for measuring soil parameters in a field environment. The module uses the Low Power Wide Area Network (LPWAN) technology to exchange data with an external database. This paper contains information about design assumptions, research on the existing long-range communication technology solutions and description of the design process.

This paper presents a method for determining a six-port reflectometer's response to a matched load with the use of partially known calibration loads. It utilizes nine calibration loads which can be of unknown magnitude and phase, however, three of them must exhibit magnitudes possibly close to each other with a reasonable phase separation. The algorithm was tested with the use of an exemplary broadband six-port reflectometer operating over the frequency range from 2.5 GHz to 3.5 GHz. The power values obtained using the proposed method are very close to those directly measured by the six-port reflectometer with a broadband matched load from precision calibration kit connected as DUT.

In this paper authors presents very important problem of estimation capacitance structures used in MEMS sensors. The importance comes from fact that during operation, inertial sensors which are build of solid materials deform because of external forces acting on them. Therefore typical capacitor consists of some electrodes changes its value because electrode changes its orientation. Here authors use analytical and FEM results to compare capacitance results and impact on accuracy of measurement.

In the paper authors take into considerations results of analysis both MEMS accelerometers and gyroscopes under performance that can be changed by some geometry details modifications. Authors considers different types of shapes of springs to show, how they influence on total device operations.

The instantaneous frequency measurement (IFM) devices are very useful for very fast measurement of current frequency value of microwave signals even if their duration is extremely short. A fast measurement of temporary value of frequency is based on evaluation of a phase difference of signals propagating through the microwave transmission lines having unequal but known lengths. This phase difference is provided by so-called proportional phase shift forming network (PPhSFN), and the phase difference measurement is performed by the microwave phase discriminator (MPhD). The main segment of MPhD is a microwave six-port made of several microwave splitters and combiners. The paper presents integrated version of microwave correlator containing PPhFS and six-port on a single printed circuit board (PCB). The developed device was designed to work over WiFi frequency range. The frequency bandwidth of the made correlator reaches nearly one octave.

The paper presents the attempt of finding optimal solutions regarding the emission type, basic emission parameters and channel capacity for the trans-ice longwave communication channel, as deployed in June 2019 during the first edition of the IGLUNA programme - a simulated lunar habitat in the Klein Matterhorn glacier in Switzerland. The experimental system is compared to lowland high-power longwave systems, the optimal emission type for different conditions (modulation index, demanded presence of carrier) is presented and the maximum possible channel capacity in relation to the achieved signal readability is calculated.

High power electromagnetic pulse weapon (EMP) is a new kind of weapon which can directly transmit high power microwave to damage the target electronic equipment. This paper introduces the damage mechanism of high power microwave, describes the working principle of the marine navigation radar and the front-end structure of receiver. The damage ability of high power microwave to marine navigation radar receiver is calculated and analyzed, at the same time, the damage range of high power microwave to marine navigation radar is given under the different states of power center and power edge.

3D printing offers a very innovative opportunity for creating cheap or special rf-components like waveguides, couplers or antennas. However, these components require electrical conductive materials to be built of. Therefore, selective laser melting of metal powder is also an attractive production technology. In this paper, horn antennas and a directional coupler at 24 GHz are shown and their production technologies are compared. By presenting a K-band branchline coupler it is shown that selective laser melting has some advantages over 3D printing.

The proposed radar system is characterized by cheap equipment (omnidirectional microphones, a computer for signal processing, and peripherals) and by the special algorithm of signal processing, which has been developed and tested during full-scale experiments with real targets: aircrafts and UAVs. A key feature of the developed algorithm is a fast method of estimation of wideband ambiguity function. In addition, the algorithm provides visualization of the target location process using the projection of the ambiguity function onto a coordinate plane. The developed radar system is proposed to use for aircraft noise management in the vicinity of an airport and for localization of small-sized flying vehicles. The results of the experiments are presented in the paper

the Weightless(-P) is a narrowband communication system designed for the Internet of Things, along with some other counterparts such as Lora and SigFox. As a system dedicated specifically for long-range operations, it possesses a considerable processing gain for the energetic link budget improvement and a remarkable immunity to multipath and interference. The paper describes outcomes of measurement campaign during which the Weightless(-P) performance was tested against variable interference, generated in an anechoic chamber. Results allow to quantitatively appraise the system behavior under these harsh conditions with respect to the modulation and the resultant bandwidth. The outcomes allowed to propose recommendations regarding the use of particular system settings to optimally fit environmental conditions. Finally, the paper provides an analysis in which CNIR is converted to the Interference Margin and its value is checked against an intentional jammer approaching the base station to verify how different Weightless operational modes respond to electromagnetic jamming.

This paper deals with a model-order reduction method, applied to speed-up the simulations of MIMO antenna arrays, performed by means of finite element method. The obtained results of the numerical tests show that the described technique is reliable and considerably increases the efficiency of the standard finite element method.

Radar technology in the mm-wave frequency band is a promising approach for the detection of birds and bats at wind turbine installations in order to reduce fatalities either by direct collision of the animals with the rotor blades or through barotrauma. In this paper we present an FMCW radar system with 1 Tx and 9 Rx operating in the Ka-band from 33.4 GHz to 36.0 GHz. The radar system is installed at the tower of a 2MW wind energy plant about 95m above ground. The data acquisition is described in this paper including the real-time processing pipeline, followed by exemplary bird detections. Also the detection of drones, serving here as an artificial flying object with a defined flight path, will be presented and discussed. Validation is performed by concurrent camera recordings.

The specially calculated reflecting surfaces with Stealth invisible quality designed for to avoid vertical ones for ra-dar beam and to reflect beam "to the milk". Stealth coatings with the full absorption of the micro-wave radar radiation on his surfaces are blackbody and reasonable to consider it as the matched loading with the corresponding physical outside temperature. A lot of news and minding has place about the Stealth application especially in the contest of an airplanes. Possi-bility to avoid the disclosing of an airplane on the big dis-tances is main advantage of this Stealth "addition" against of the radars. But in much cases for the microwave radi-ometers this Stealth coating can be good for the real deter-mination by the passive devices because their job based on the measuring the radio-brightness contrast between Stealth objects and the background of the environment/s (sky is cold, Earth is warm). The aim of this short report - to present some under-standing about to use radiometer about Stealth objects

In this paper, influence of dielectric overlay permittivity on miniaturized ESPAR antenna parameters is presented. ESPAR antenna is a low-cost and energy-efficient way to implement beam steering capability to a node and improve network performance. The antenna size reduction is obtained by embedding its active and passive elements in ABS based materials of relative permittivity equal to 4, 5.5 and 7.5 in order to achieve network node compact size. Simulation results of three optimized for particular dielectric constant designs are presented and tradeoff between dimensions reduction and performance is discussed. Selected materials and antenna design are dedicated to be fabricated in 3D print technology, so can be easily prototyped.

Microwave propagation in the atmosphere is affected by air temperature, humidity, attitude, and other factors, there are many related researches on the above influencing factors, but relatively few researches are attached on the microwave propagation characteristics under the condition of sea salt mist. It is of great significance to clarify the law of microwave propagation attenuation under the condition of salt mist for the microwave applications such as maritime communication and radar detection. Firstly, the parameters of the salt mist environment are analyzed and modeled in this paper, and it is driven that the relationship between the concentration of the salt mist and the dielectric constant of the atmosphere. Then, based on the FDTD numerical analysis, the microwave propagation law under different concentration of the salt mist is calculated and compared with the theoretical analysis results.

This paper describes an experimental setup that was built to imitate the performance of the new microwave personnel screening system, in which synthetic aperture is formed due to relative motion of the subject in the vicinity of a sparse antenna array. The RGB-D sensor captures a color image and a depth map of a still scene with a mannequin, while the compact network analyzer, which is moved by a two-dimensional scanner, acquires the samples of the radar signal reflected from the same scene. The mannequin is moved by the third linear drive module to another position, creating the next still scene to be scanned and captured similarly during a single experiment. The collected data is stored for the following joint processing. Preliminary radar images of concealed objects on mannequin are obtained and demonstrated. The use cases of the experimental setup are described toward designing a sparse electronically switched antenna array: finding the required number of the channels, choosing proper frequency band and bandwidth, antenna type, and others.

The paper presents an algorithm for positioning of a handheld ground-penetrating radar antenna. The algorithm has been elaborated for processing range measurements in a currently developed positioning system based on ultrawideband radio modules. Such a system is planned to be used as a support for a handheld ground-penetrating radar as continuous and accurate positioning of its antenna can facilitate creation of high-quality subsurface images. The paper contains a short description of the developed system and focuses on its Kalman filter used for positioning. Here, we consider using a novel dynamics model, based on a pendulum motion model, which provides a more adequate description of the antenna's dynamics than abstract position-velocity or position-velocity-acceleration models, commonly used in navigation systems. Chosen simulation results which support this claim are presented.

The paper presents an implementation of analog front-end designed for use in an X-band Frequency Modulated Continuous Wave (FMCW) radar system. Fine range resolution is achieved because of using more than 1 GHz of bandwidth, which is achieved through application of frequency multipliers. The system has been tested in laboratory as well as in a real environment using a USRP (Universal Software Radio Peripheral) device for both, waveform generation and beat signal digitization.

Background subtraction is usual step in impulse radar applications. It is used to not only remove clutter - reflections of all the stationary, mostly irrelevant objects, but also crosstalk. Various techniques are used for clutter/crosstalk removal. These are briefly over-viewed. Focus of this paper, however, is on proposed method of adaptive background subtraction, which is statistical real time method based on developments of entirely different field (Computer Vision)

This paper explores the possibility of using a synthetic aperture radar to detect surface defects of rails and measure parameters of rail junctions. Experimental data were obtained with a setup consisting of a two-coordinate electromechanical scanner and a radar emitting continuous stepped-frequency signal in the range of 22.2 - 26.2 GHz. As an object of study, fragments of narrow-gauge rails were used, in which surface defects of various sizes and depths were created. A phase method for radar signal processing based on the backward propagation of its wavefront was developed, with which radar images of rails with defects were obtained. Experimental studies have shown that the developed rail surface imaging method allows detecting the presence and measuring characteristics of cracks on the tread, cleavages of the railhead, the width of the joint gap and the magnitude of the vertical step at the rails joint. High accuracy and sensitivity of the radar method, confirmed with the contact measurements matching, allow using it for fast noncontact diagnostics of the rails condition.

For polarimetric synthetic aperture radar (PolSAR) images, building extraction has been a challenging topic for long time in applications of land-use and land-cover analysis. Due to similar structures of buildings and such vegetation as forest, they often exhibit similar PolSAR scattering characteristics that are often difficult to distinguishing. Recently, deep Convolutional Neural Network (CNN) has been widely investigated for image processing with many promising results. This paper proposes a method that combines polarimetric features with the CNN network to realize the comprehensive utilization of polarimetric and contextual information of PolSAR data for the extraction of building areas in PolSAR images. Comparison experiments on both ESAR and EMISAR L-band PolSAR datasets show that the proposed method can generate better results for building extraction.

Recently, Interest on circular SAR (CSAR) has been increased in researchers. The sub-aperture division and trajectory reconstruction of ground moving target are important parts of the CSAR research. Firstly, the CSAR sub-aperture is fitted by a second-order curve, which achieves better focusing quality than the traditional fitting method. Next, parameter estimation accuracy is improved of each CSAR sub-aperture. Finally, the trajectory of ground moving target is reconstructed. Simulated data are used to prove the effectiveness and correctness of the proposed method.

This paper introduce an approach for detecting bridges when the difference in radar echo energy is not obvious. It consists of two steps: extracting targets with high anisotropy and detecting bridge. Firstly, by image segmentation based on the feature of multi-aperture polarimetric entropy, we get targets with high certainty. And then we utilize edge detection to extract straight line segmentations. Finally, the parallel straight line segmentations which meet the bridges' geometric properties are selected as bridges. The proposed approach has been test with polarimetric CSAR data, and the experimental results show that our method can detect bridges effectively.

A novel global range alignment technique for inverse synthetic aperture radar (ISAR) imaging is presented in this paper. Instead of requiring the parametric model for the relative offset amongst the range profiles, the alignment is investigated from the viewpoint of optimization, where the minimization of the entropy of the sum range profile (SRP) is employed as the optimization criterion. The precise range alignment within a range cell can be achieved by implementing the proposed algorithm. With respect to the existing global method, the proposed one does not require any interpolation operation and multidimensional search operation. Experimental results based on real measured data of maritime non-cooperative target validate the effectiveness and the efficiency of the proposed algorithm.

In this paper, a general iterative thresholding algorithm (ITA) for solving Lq-norm regularization problem is proposed to achieve the synthetic aperture radar (SAR) image feature enhancement. Compared with the reconstructed images by matched filtering (MF) based method, the proposed method recovered images have lower sidelobes, reduced noise and clutter, which improves the image quality effectively. Experiments basedon Gaofen-3 (GF-3) SAR complex image data are used to validate the proposed method.

A real-time imaging right side-looking synthetic aperture radar (SAR) motion error model is established in this paper, and a center beam motion compensation algorithm based on inertial navigation and phase gradient autofocus (PGA) motion error estimation is adopted. The algorithm compensates the echo envelope and phase separately, and uses the inertial navigation data to straighten the echo envelope with motion error, and then uses the phase gradient autofocus algorithm to estimate and compensate the phase error of the echo. In view of the characteristics of real-time imaging, such as short time, large amount of computation and limited computing resources, the algorithm cancels the steps of range migration correction, projects the motion error vector on the slant plane, and completes envelope correction and phase error estimation. The method has a small amount of calculation and can meet the resolution requirement. The simulation results show that it can obtain high quality SAR images.

Surveillance radars form the first line of defense in border areas. But due to highly uneven terrains, there are pockets of vulnerability for the enemy to move undetected till they are in the blind range of the radar. This class of targets are termed the 'pop up' targets. They pose a serious threat as they can inflict severe damage to life and property. Blind ranges occur by way of design in pulsed radars. To minimize the blind range problem, multistatic radar configuration or dual pulse trans- mission methods were proposed. Multistatic radar configuration is highly hardware intensive and dual pulse transmission could only reduce the blind range, not eliminate it. In this work we propose, elimination of blind range using deep learning based video tracking for mono static surveillance radars. Since radars operate in deploy and forget mode, visual system must also operate in a similar way for added advantage. Deep Learning paved way for automatic target detection and classification. However, a deep learning architecture is inherently not capable of tracking because of frame to frame independence in processing. To overcome this limitation, we use prior information from past detections to establish frame to frame correlation and predict future positions of target using a method inspired from CFAR in a parallel channel for target tracking.

Space-Time Adaptive Processing (STAP) enables detection of a moving object against the background of strong interference by radar. The fundamental principles of the STAP technique for radar signal processing in particular, detecting slow moving objects against interference. are presented in this paper. The parameter (improvement factor), determining the performance of any linear processor was analysed. A disturbance model has been proposed, for which the dependence determining the performance of any STAP processor has been derived. The results of simulation of the optimal processor performance against the suboptimal processor for three different values of noise to interference ratios in reference channels were presented in the paper.

This paper concerns the problem of maximum likelihood (ML) estimation in the case of impulsive observations modeled by heavy-tailed α-stable distributions. To describe analytically the cost function in ML estimation criterion the Fox function representation of α-stable distributions is used.

The paper presents the results of experimental studies on evaluation of employing digital predistortion based on simple feedforward neural network for linearization of microwave power amplifiers. The influence of the number of neurons in the hidden layer, the number of delayed input samples at the input of neural network, as well as the number of samples taken for learning a neural network were studied and discussed in the paper. The main goal of this work was to establish the minimal configuration of the neural network which can be used for linearization of power amplifiers excited by wideband and high PAPR signals, e.g. LTE. The results obtained for neural networks were compared with the results obtained for the conventional predistortion method based on memory polynomial.

In some applications such as radio transmitters with loop antennas, h.f. drivers for RFID transmitting coils, wireless h.f. power supplies for biomedical implants and endoscope capsules etc. resonant power amplifiers operate with high-reactance and low-resistance load. The paper analyses an off-nominal Class E ZVS amplifier to identify conditions for its high-efficiency operation with low-resistance load. Power loss of the transistor switch in Class E amplifiers with normalized transistor turn-on time D= 0.5 operating in nominal and off-nominal conditions are compared. Analytical closed-form estimations for power losses in the transistor switch in the off-nominal amplifier are given. Theoretical results experimentally validated have demonstrated that by designing the off-nominal Class E amplifier for a high enough dc supply voltage the power losses in the transistor switch can be significantly reduced. This makes the circuit useful in those applications that require the amplifier to operate with high output current and/or low-resistance load. A laboratory model of the off-nominal amplifier was designed and built to operate at the frequency 140 kHz with output power 50 W, dc supply voltage 24 V, load resistance 2Ohm and D= 0.5. Its measured efficiency was 96 %.

Practical realization of gain-switched Dy3+-doped ZBLAN fiber laser operating at 2.94 µm is reported. The laser is pumped by a 1.1 µm Q-switched ytterbium (III) fiber laser, which was constructed in-house. The ZBLAN fiber laser generates a stable pulse train with repetition rates spanning the range from 25 to 100 kHz. At the repetition rate of 50 kHz, the pulse width is 183 ns while energy and peak power are 0.76 µJ and 4 W, respectively.

In the paper a ballistocardiographic sensor for remote monitoring of activity and vital parameters is presented. The sensor is mainly intended for use in monitoring systems supporting care of elderly persons. It allows to detect occupancy of the piece of furniture, to which it is attached and for estimation of basic vital parameters (heart rate and respiration rate) of the monitored person. The presented device includes three inertial sensors: two accelerometers of different parameters and price and one reference BCG module. The device sends the measurement results to the external server over WiFi. The vital parameters are estimated based on the Continous Wavelet Transform of the registered acceleration signals. The occupancy of the piece of furniture is detected through analysis of current standard deviation of the measured acceleration.

In high-efficiency Class E amplifiers matching circuits are commonly used to transform usually constant load resistance to nominal or off-nominal resistance of the amplifier to ensure its ZVS operation. In some applications such as: wireless power transfer systems, plasma generators, dc-dc power converters as well as in some transmitters Class E amplifiers operate with load resistance or impedance varied in a wide range. This requires that the matching circuit transform the whole range of load resistance into the range of nominal and off-nominal resistance of the amplifier. The paper presents theoretical results for Class E ZVS amplifier with basic parallel π1a and π2a matching circuits loaded with variable resistance. Conditions for ZVS operation of the amplifier with transistor duty cycle D=0.5 and the matching circuits loaded with any load resistance are discussed. Analytical expressions setting the boundaries for ZVS operation of the Class E amplifier with the analyzed matching circuits are given as well. Examples of normalized characteristics of output voltage and output power vs. load resistance for the amplifier are also presented. A design example for the Class E amplifier with π1a matching circuit able to operate with any load resistance is described and verified by simulation with LTSpice.

In a presentation, we shall recall about Fano resonance phenomena, make a brief review on Fano resonances found in metasurfaces, and present recently found Fano resonance in a mirrored array of split-ring resonators. It appears due to the direct interaction of lattice and plasmonic modes. The resonance frequency can be changed by changing the period of the array. The high-quality factor of Fano resonance, around 100, has been evidenced experimentally. Possible applications of the Fano resonance will be considered.

The ability to make accurate and repeatable measurements, rapidly and over wide bandwidths, is essential to more widespread use of the sub-millimeter and THz spectrum. This talk gives an overview of the last two decades of advances in this area. We trace the progression from development and construction of the extremely sensitive superconducting heterodyne receivers in the Atacama Large Millimeter Array (ALMA) to the commercial availability of general frequency extension modules for common microwave test equipment up to 1 THz and beyond. We also describe emerging moderate-volume applications for submillimeter-wave and THz sources and receivers, including small satellite constellations for atmospheric modeling and weather forecasting.

The existence of thermal noise in the channel of a MOS field effect transistor was postulated in early work by Klassen and Prinz [1] and since has been wholeheartedly adopted by the CMOS community as a relatively recent review paper clearly indicates [2]. A very similar approach has been adopted by the authors of BSIM series of compact models (for example [3]). However, this approach is not consistent with universally accepted noise models of III-V FETs and HEMT (see for example [4], [5]). In the latter approach, the gate noise behaves as thermal noise while the drain noise reveals behavior consistent with suppressed shot noise [6]. The drain noise is highly suppressed for long gates by a factor of almost 10 while for very short gates the drain noise approaches a pure shot noise [6], [7]. In fact, almost pure short noise has been experimentally observed in 10 nm gate length CMOS devices [8]. A reduction in gate length improves cut-off frequency but also increases drain noise. These two counter-balancing effects explain why for short gate devices expected improvements in MOSFET noise temperatures upon further gate scaling have not materialized. This paper will explore inconsistencies in noise modeling of noise in III-V FETs and MOSFET and it will explain why the noise performance of RF CMOS has reached its natural limits.

The main goal of the conducted research was to estimate the errors of the radio distance measurements (RDMs) performed by using the DWM1000 modules. Measurement campaigns were carried out in indoor environment, for static cases in four different places, i.e. wide corridor, narrow corridor, sitting room, and building's hall for LOS (Line-Of-Sight) and NLOS (Non-Line-Of-Sight) conditions. Additionally, dynamic measurements in typical classroom were made. For the static scenarios, analysis of RDMs errors were presented. In dynamic case, dependencies between changing LOS/NLOS conditions and simultaneous RDMs increase was noticed.

In the article the concept of the radiolocalization subsystem of VHF communication for aviation VCS-MLAT (Voice Communication System - Multilateration) is presented. The distributed localization system will estimate the position of the aircrafts by the audio signals transmitted in aircraft band (118-136 MHz). This paper presents the measurements to check if voice airband communication can be used to estimate the position. Also main assumptions of the project and describes the structure and scheme of the localization modules are presented. At the end of the article the preparation for the final test in the real environment is concluded.

The article discusses the suitability of the multiwall radio wave propagation model for RSSI reference data preparation for fingerprinting-based indoor positioning applications. Localization system employs Bluetooth Low Energy beacons and mobile device to determine position of the user within the test area. The proposed system uses particle filter algorithm to estimate the user's current position from RSSI measurements and knowledge of reference electromagnetic field distribution computed for each beacon located in the building. The results of the comparison between the use of multiwall and ray tracing propagation models for indoor localization purposes has been shown. The relation between the time needed to prepare mentioned reference data was also demonstrated. Presented results show that for some cases it is possible to use less complex propagation models without losing sufficient localization accuracy but for the benefit of the time and complexity of calculations needed to prepare reference data for presented indoor localization application.

Due to confined spaces and various obstacles e.g. walls, furniture, indoor environment may be considered as a harsh and disturbing in terms of indoor radiocommunication services. The given paper presents FNN (Feedforward Neural Network) method for LOS (Line-Of-Sight) and NLOS (Non-Line-Of-Sight) identification which may support mitigation of such a negative influence. Described FNN architecture was evaluated based on a real indoor measurements collected with the use of the UWB (Ultra Wideband) radio modules.

A hybrid technique combining finite-element and mode-matching methods for the analysis of scattering problems in open space is presented here. The main idea is based on impedance matrix descriptions of the boundary surrounding the discrete computational domain and combine it with external field described analytically. The discrete analysis, which is the most time- and memory-consuming, is limited here only to the close proximity of the posts or fragments of post which geometry is complex. All the obtained results have been verified by comparison with simulations performed using alternative methods or commercial software.

The electromagnetic modeling principle aided with artificial neural network to designing the microwave wideband elements/networks prepared in microstrip technology is proposed in the paper. It is assumed that the complete information is known for the prototype design which is prepared on certain substrate with certain thickness and electric permittivity. The longitudinal and transversal dimensions of new design are calculated separately using the scale coefficients which are determined from transmission line equation. Next the artificial neural network can be used for final tuning which should take into account the dispersion of microstrip line. The verification of proposed procedure is shown for exemplary planar UWB balun.

A fully automated reliable greedy multipoint model-order reduction (RGM- MOR) approach is presented. The subsequent block moments added to the projection bases are orthogonalised by means of the Modified Gram-Schmidt method. Although the orthogonalization process slightly increases the computational time, a significant improvement in performance can be observed in projection basis size, the accuracy of the error estimator, and reliability of the whole reduction process, compared to the GM-MOR technique. The improved quality of the error estimator has a significant effect on the size and accuracy of the reduced-order models. Compared to GM-MOR, the new algorithm yields more compact and more accurate models, allowing wideband reduced-order models to be constructed automatically with an accuracy a few orders of magnitude higher than was previously possible. Moreover, the efficiency of the orthogonalization process is increased, by utilizing the parallel computations using the graphic processing units (GPUs).

This talk focuses on electromagnetic waves in connection with boundaries and surfaces, in particular in the case when the material contrast over the boundary is non-conventional, like often in connection with the analysis metasurfaces. The problem will be approached from the point of view of general electromagnetic boundary conditions: conditions that dictate two relations for (a combination of) the normal and tangential components of the electric and magnetic vector fields at the surface.

In particular, the concept of a matched wave (a wave with such a polarization and incidence state that it itself satisfies the boundary condition, and as such can exist without causing a reflection) will be discussed and illustrated through examples. The talk draws some material from a recent book, coauthored by the speaker (I.V. Lindell and A. Sihvola: Boundary Conditions in Electromagnetics. IEEE Press, Wiley, Hoboken, NJ, USA, 258 pages. ISBN: 978-1-119-63236-8).

The international union of radio science URSI (Union Radio-Scientifique Internationale) is a non-governmental and non-profit organization with mission to stimulate and coordinate research, applications, and international co-operation in the field of radio science. During the present times, URSI celebrates its centenary. Within its technical activities, URSI is divided into ten scientific commissions, and member commissions operate in 44 countries.

This talk takes a look at the history and present state of URSI, in particular from the Finnish, Scandinavian, and Baltic sea region perspective. The potential of the contributions of Baltic countries into URSI activities will be highlighted.

In order to develop safety-reliable standards for IoT (Internet of Things) networks, appropriate tools for their verification are needed. Among them there is a group of tools based on automated symbolic analysis. Such a tool is Tamarin software. Its usage for creating formal proofs of security protocols correctness has been presented in this paper using the simple example of an exchange of messages with asynchronous encryption between two agents. This model can be used in sensor networks or IoT e.g. in TLS protocol to provide a mechanism for secure cryptographic key exchange.

In this study, the new architecture of the optical switching fabric is proposed. The banyan-type switching networks, well known in switching theory, are composed of symmetrical dxd switches. The new architecture considered in this study is built from mostly asymmetrical optical switching elements. It is shown that the new proposed structure requires a fewer number of passive as well as active optical elements than the banyan-type switching fabric of the same capacity and functionality. It also contains one stage fewer, which, from the optical switching point of view, is an important feature as well.

One of the recent approaches for improving capacity of future wireless network is to increase the density of nodes by deployment of short-range base stations called small cells. When the number of such nodes is high, one may think of so-called ultra or extreme dense networks. In such a case, the efficient management of consumed energy is crucial. In this paper, we discuss the concept of transmit profile selection applied in dense wireless networks. Each profile is defined by the tuple of certain parameters which specify the transmit characteristics of each node, and in consequence allows for assessing total power consumption. Two power profiles has been defined, where one considers transmission using advanced channel coding algorithms and the other utilizes simple modulation schemes with no channel coding. Computer simulation has been performed to compare the performance of the network operating in one of these modes.

Deployment of small cells in heterogeneous network is directly related to the problem of right user association between macro- and small-cell base station. In order to force just selection of appropriate base station, additional component is added to the measured path loss (signal strength) in order to modify, i.e. virtually extend or squeeze, the cell radius. In this short paper, the authors present the concept of using the Cell Range Extension parameter in coordinated LTE-A networks. Within the coordination area that covers numerous base stations, the values of CRE are tuned in such a way that the achieved network throughout is improved. It is to improve network throughput by proper user assignment to the BS.

Monitoring volumetric water content (VWC) at several depths in the soil profile can be performed using either a few soil moisture sensors placed at various depths or a profile probe. The use of a profile probe is less disturbing to the soil, less laborious more convenient, and more cost-effective. The objective of the paper is to estimate the dependence of the depth of the sensitivity zone of a single section of a profile probe working in the time-domain transmission mode (P-TDT probe) on the probe's diameters. This issue was assessed with the use of the finite element method (FEM) simulations in the frequency domain. The scattering parameters matrices obtained in the simulations were transformed to the time domain. Based on the results, the depth of the sensitivity zone was estimated for different probe diameters. It was concluded that the effective soil volume measured by the profile probe of a given geometries is in range 14.3 to 30.9 mm around the tested probe.

Describes a method for measuring the equivalent reflection coefficient of feedthrough power standards. The analysis of measurement error and comparisons of results against other methods is done. The proposed method is universal and does not depend from design of feedthrough power meter.

We present a method for temperature-dependent calibration of a multichannel measurement system for 0.05-3 GHz characterization of material complex dielectric-spectrum. This system, described elsewhere, is based on one-port vector-network-analyzer measurements of a two-port coaxial-cell terminated with a variable load. The nominal system calibration uses multiple coaxial transmission-line sections terminated with a variable termination, and due to a large number of calibration standards is difficult to implement in a multichannel system at multiple temperatures. Therefore, we devised a new variable-temperature calibration approach. In this approach we assume that the temperature variation causes only small changes of the system calibration coefficients, and determine those changes with approximate calibration techniques requiring a lower number of calibration standards. We verify our approach based on measurements of PTFE samples at temperatures from 0 to 40 degrees Celsius.

A commonly used strategy for removing clutter from weather radar echoes is to employ Fourier processing to eliminate the zero-velocity Doppler moment and subsequently re-transforming the residual frequency domain signal back into time domain. This method, though in common use, increases the computational load and it also tends to reduce the signal-to-noise ratio of the processed signal. In this contribution, a new method that employs the target properties will be suggested for removing clutter from weather radar echoes using a computationally economic algorithm. This method for filtering weather radar echoes will exploit the temporal properties of the clutter signal and the useful ‚target signal'. The suggested processing algorithm lends itself to easy implementation provided simple 'a priori' knowledge of the temporal characteristics of the signals involved is either known or readily obtained from the radar measurements themselves.

We would like to invite all the participants of the conference to join the presentation about emotions in our life, and how to deal with them and as a result manage stress.

Emotions are states connected with pleasure or unpleasantness. They are also reactions to the positive or negative stress. We can describe emotions of human beings and animals, and perhaps - also plants.

In general, it is common to believe negative emotions are bad, but we shouldn't forget that they have also positive energy. If our different needs are not fulfilled from the early childhood we don't have the mechanism to develop many emotions at certain level. That could lead us to various psychical and physical illnesses and as a consequence to shorter life expectancy. Therefore it is very important to form our psychological resiliency to stres. That is why special Ego Resiliency Scale was created by Block and Kremen in 1996. Moreover the mechanism of the positive desintegration described by Kazimierz Dąbrowski enriches all human life and broadens horizons of thinking and feeling and can become the inspiration to the creativity in different domains.

The research on Mirror Neurons by Giacomo Rizzolatti is vital in the process of emotion's "contamination". Nowadays, due to the technical progress, many various experiments in this area are carried out with the help of optogenetics e.g. by Phd. Ewelina Knapska from Nencki Institute.

Emotions can cause psychosomatic illnesses, addictions and anyone can be object of manipulations because of emotions. We would like emphasize that the appropriate diet and exercises help us to deal with emotions and influence our behavior in a positive way.

Time Domain Transmissometry (TDT) is one of the methods of electromagnetic metrology. This method, similarly to TDR, is mainly used to measure parameters of transmission lines and connectors. It is also suitable for determining the dielectric properties of materials from which the transmission line is built. It is known that water has a high dielectric permittivity of about 80. This means that the volumetric water content of the soil has a decisive influence on its dielectric properties. A transmission line placed in the soil can be a detector of dielectric properties and then soil moisture. For these reasons, the TDR and TDT methods are commonly used to measure and monitor soil moisture. The selection of materials shape and construction of the transmission line are a constant challenge for the sensor designers. The probe's construction should be watertight and materials used for construction should not absorb water. The paper presents selected research results concerning the design of soil moisture sensor and signal analysis to determine bulk dielectric permittivity.

Dielectric sensors operating in time and frequency domain can be used to determine soil moisture content. There is still a need for developing new sensors for determination of soil water content, in order to further improve measurement accuracy, lower the price or adapt the equipment for special applications. For example, many of the existing soil moisture probes do not allow precise measurement of dielectric properties in a small volume because of their construction. The paper presents the evaluation of a seven-rod probe for an accurate determination of soil water content in a small sample volume. Firstly, digital simulations for sensitivity zone of the tested probe were performed. Next, the prototype probe was tested for two soils with various texture and moisture content in the range from air dry to near saturation. The values of dielectric permittivity (frequency domain) and apparent dielectric permittivity (time domain) were calculated from the measured S11 parameters. The obtained data was compared with the reference Topp's equation. It was concluded that the tested probe is able to accurately measure soil moisture in a small volume in the range of frequencies from 20 MHz to 200 MHz.

The work presents test results of an open-ended probe with an antenna (OE-A) as a tool for the measurement of soil water content. The measurement volume of OE-A is larger compared to a classical coaxial open-ended (OE) probe, making the considered probe applicable in agrophysics. To correctly assess the reliability of the probe, both numerical simulations and measurements were done. Two types of the mineral soils with different moisture were analyzed in the frequency range 1 MHz - 6 GHz using vector network analyzer (VNA) one port (reflective) measurements.

We present a wideband characterization of soil complex dielectric permittivity spectra in the frequency range from 40 Hz to 500 MHz. Soil samples of various moisture content were measured with the use of a seven-rod probe, which was connected to an impedance analyzer and a vector-network-analyzer through a switch controlled by a PC. The use of a single probe in connection with both analyzers ensured that the same samples were examined in the whole frequency range, without the density changes nor significant moisture variations between the consecutive measurements by the analyzers. The spectra obtained from both instruments were merged and analyzed with the use of a combined permittivity and conductivity model.

Water as the precious resource necessary to sustain life on the Earth should be used in the sustainable way. This is especially important to that part of water that directly affects living organisms, that is soil water. Its total volume is about 0.001% of total water on the Earth but its importance in the habitat of all living creatures is priceless especially for food production and climate regulation. Therefore, soil water amount and quality should be monitored in automatic and non-invasive way. The paper presents electromagnetic methods and sensors for monitoring soil water content. Special attention is put of the respective microwave tools, their advantages and prospects for the future of soil moisture metrology.

Detection and localization of physical radiating sources allows to allocate hotspots with substantial emitting power on the surface of the printed circuit board (PCB) of the electronic device. Electromagnetic emissions caused by data transferring signals can be mathematically described by cyclostationary stochastic processes. The optimal detection of cyclostationary stochastic process with known two-dimensional autocorrelation function (ACF) assumes two-dimensional cross-correlation between the shifted product of the stochastic process and relevant ACF. The proposed detection algorithm is based on the degree of cyclostationarity (DCS), defining by comparison of evaluated ACFs obtained from the measured realizations of stochastic process. Experimental verification of the proposed algorithm was implemented by near-field scanning of two spatially distributed sources with different cyclic frequencies on the surface of the PCB.

Estimation of statistical characteristics for radiated electromagnetic emissions caused by PCB can be implemented by statistical signal processing of time domain signals measured by near-field scanning system. The relation between the source signal and the signals measured by the near-field probe at each scanning point can be modelled by linear transformation of the source signal. In this paper modeling procedure for near-field to far-field propagator based on Jefimenko's equations is presented. Radial component of instantaneous power density represented by Poyting's vector was derived from the modelled electric and magnetic far fields components. Synchronized impulse responses can be used for computer aid prediction of the spatial-time evolution of the cyclostationary characteristics in the environment surrounding the PCB. The 2D periodic ACF of the far-field shows the cyclostationary properties similar to the properties of initial random bit sequence.

Antennas belong to the key components of wireless communication devices. Strict design specifications imposed on modern systems can be fulfilled only by complex antenna structures. Their computational models have to be of high fidelity to ensure reliability, i.e., sufficient agreement between simulations and physical measurements of the fabricated prototypes. A prerequisite for that is utilization of full-wave EM analysis but also incorporation of the peripheral components. EM-driven design of high-fidelity models using conventional optimization algorithms is often impractical due to high computational cost entailed by a large number of simulations required to find a desired solution. In this work, a low-cost optimization of antenna structure with peripheral components is discussed. The performance of the presented approach is demonstrated using a bandwidth-enhanced quasi-patch antenna optimized to maximize the gain while maintaining acceptable in-band reflection. The results indicate a fifty-percent reduction of the design cost compared to a benchmark algorithm.

Wireless Body Area Networks operate in the proximity of human body. This is complex environment that affects the operation of wearable antennas changing their input impedance. This effect can be simulated with numerical models of human body. For the sake of prototype antenna measurements the physical model is used that should correspond to the numerical one as well as to the body of human subject. In this paper a simplified numerical and physical model of human body for antenna input impedance analysis is presented. It is suitable for computer simulation because it has reduced size and complexity. At the same time, its physical equivalent is easy in fabrication due to the selection of available materials. The results of numerical simulations and measurements of antenna impedance mismatch performed with this model are in good correspondence to the results of measurements obtained with human subject.

Modern linear particle accelerators are large-scale facilities utilizing normal and superconducting microwave resonator cavities to increase energy of physical particles such as electrons or protons. Particles travel at velocities comparable to the speed of light through the cavities and high-gradient Electro-Magnetic fields must be extremely precisely amplitude and phase controlled in order to assure proper acceleration of the particle beam. Sophisticated accelerating field controllers and beam diagnostic systems require synchronization reaching tens of femtoseconds in time domain or 0.001 degree in phase at RF frequencies. In larger accelerators like the E-XFEL in Hamburg, there are several thousands of synchronized devices distributed along 3,4 km long machine. This talk will cover challenges and solutions used to distribute RF synchronization signals in large scientific machines, including control of phase noise and phase drift in components of the synchronization system.