ABSTRACT. The induced by the changing magnetic field bending vibration of the microribbon Fe73.5Cu1Nb3Si13.5B9 with the fixed one end at the range of low sound frequencies is experimentally observed. The as-cast and annealed samples are tested for low-frequency resonant vibrations. In the given region of frequencies for an inducing magnetic field, the resonant frequencies of the induced mechanical vibrations are found. The decay coefficient, measured for the mechanical self-vibration of the annealed sample, is derived. When a relatively weak permanent magnet approaches the microribbons in the direction, perpendicular to the bending vibration, the cessation of the mechanical vibration in the direction is sighted for both, as-cast and annealed samples. The spin nature and the corresponding contribution of the Einstein–de Haas effect are discussed to explain the observed.

ABSTRACT. For the first time, the pinning force of domain walls was studied by the NMR method of a two-pulse spin-echo under the action of an additional magnetic video-pulse. It is shown that the pinning value is inversely proportional to the length of the magnetic video-pulse. In addition, the area of the magnetic video-pulse turned out to be the constant for all threshold durations of the magnetic video-pulse. The dependence of the pinning force H0 on the external constant magnetic field He is studied. It is shown that up to  3 kOe, a linear dependence of H0 on He is observed. This indicates that, as He increases, the domain walls are distributed over positions corresponding to the stronger pinning centers.

ABSTRACT. We have developed a method for solving the electrodynamic problem for a perfect electric conducting spherical cavity in which a spherical dielectric inhomogeneity is randomly located with respect to the center of the structure. No limitations on the size or on the relative position of the inner dielectric sphere are imposed. The electromagnetic field is appropriately expanded in terms of Hertz potentials. One of features of the method is the ability to satisfy the boundary conditions at the interface between the two media, as well as on the outer metallic spherical surface, at individual points located on these boundaries. In this case, there is no need to integrate and formulate boundary conditions for each basic mode, as it is usually done by classical methods for solving electrodynamic problems in the frequency domain. In the present contribution, we carry out a numerical study to compute the eigenfrequencies in such eccentric configurations. For this purpose, we extract the eigenfrequencies for quasi-TE and quasi-TM modes, and compare the results with an analytical technique. In addition, we validate the results and compare the computational efficiency of our method with HFSS commercial software. Our method turns out to be efficient in terms of CPU time with minimal memory consumption, as compared to the commercial solver.

ABSTRACT. In present work, a theoretical and computer-aided studies of a waveguide phase shifter for the frequency band 7.5–8.5 GHz were carried out. Frequency dependences of phase differential at the external port of the device, the standing wave coefficient and the voltage were analyzed, respectively, for a phase of 45 and 90 degrees. A theoretical analysis of the basic performances of a phase-shifting device that was created on the basis of a rectangular guide with conductiong diaphragms has been carried out. The design and characteristics of the phase shifter were given to obtain a phase shift of 45 and 90 degrees. It has been shown that designs of such devices that consist of several such sections have sufficiently effective characteristics. The paper demonstrates a comparison of the numerical dependences of the developed phase-shifting device obtained by FEM, FDTD and wave matrix methods. Proposed designs of phase shifters can be used for modern telecommunication systems for transmitting and processing information.

ABSTRACT. We study analytically the effect of charge-neutrality breaking on the spectrum of localized Josephson plasma waves (JPWs) in a plate of layered superconductor of finite thickness for the case of layers parallel to the interface. This effect results in the appearance of additional eigenmodes with anomalous dispersion and an additional forbidden region in the spectrum of localized modes near the Josephson plasma frequency. We consider both the surface and waveguide eigenmodes with symmetric and anti-symmetric field distribution with respect to the middle plane of the superconducting plate.

ABSTRACT. We consider the antenna shaped as a spherical dielectric lens with a conformal graphene disk on its surface, fed with elementary source. The latter is a radial electric dipole placed on the lens rotation axis. The electrical properties of graphene are characterized with the aid of the Kubo formulas, which are based on the quantum-theory description. First, we cast the wave-scattering problem to the dual series equations for the field expansion in terms of the spherical harmonics. Then, using the static part analytical inversion with the aid of the Abel integral transform, we reduce the dual series equations to an infinite matrix equation of the Fredholm type with elements depending on the elementary functions. This procedure guarantees the convergence and enables us to accurately characterize the considered lens antenna performance, in particular, its radiation resistance and directivity, in the THz frequency range.

ABSTRACT. Two different approaches to generalizations of the classical two-dimensional Sierpinski carpet are presented in correct mathematical sense. The first generalization is based on classical principle of fractal carpet creation. It relates to the change of the fractal creator. In the result a series of two-dimensional self similar fractal square sets can be arisen. The second generalization is reworked on the base of one-dimensional self similar fractal sets with a variable fractal dimension. For all generalized classes of self similar fractal square sets have been presented basic elements of their mathematical analyses.

ABSTRACT. This study proposes a dual-band Quasi-Yagi reconfigurable binomial weighed phased array design for the unlicensed Wi-Fi and planned 5G band for European Zone. The analytical calculations, numerical simulations, and experimental analyses are done. The antenna array operates at 2.45 and 3.6 GHz. By analog beamforming and binominal weighting, the antenna has three distinct main lobes for each corresponding phased configuration with reduced sidelobes. The simulations are done on the High-Frequency Structure Simulator (HFSS), and experimental measurements are carried out on the fabricated prototype. The numerical and experimental results are presented.

ABSTRACT. An open ring patch antenna and two versions of the antenna arrays based on it are proposed. Experimental samples of antennas are designed for a frequency of 5.8 GHz for use in video signal transmission systems for radiocontrolled models. Designs of antennas were investigated using automatic design tools and experimentally. It is shown that the gain factor of a single patch antenna can exceed 10 dBi, and the gain factor of a four-element antenna array is 16 dBi.

ABSTRACT. In this contribution, an effective strategy for the synthesis of equal-amplitude (isophoric) sparse arrays is presented. The approach consists of an iterative procedure starting from a non-equal amplitude layout. The method is very effective, and is demonstrated by an in-depth numerical analysis of a synthesis example.

ABSTRACT. The paper is a continuation of the earlier studies of the characteristics of accelerating metal-plate lenses (AMPL) carried out by the authors, intended for use in antenna devices of information systems. Compared to commonly used retardation lenses, they have such advantages as lightness, low weight, and manufacturing availability. A brief analysis of the results obtained earlier is presented. In the example of the frequency parameters of the drone control system, the problematic issues of expanding the range properties of the AMPL are considered. To solve this problem, it is proposed to use: (1) a combined lens consisting of alternating and located one above the other “floors” of lenses with parameters corresponding to two operating frequencies; (2) longitudinally corrugated lens plates. A variant of the method for calculating the distortions of phase distributions in the aperture of such lenses is presented. The options for controlling the maximum radiation pattern orientation are considered.

ABSTRACT. This document proposes a technique for forming the response of two-channel demodulators. At the same time, a string vector is used, the elements of which are the weighting coefficients of the demodulator, which are used to form the quadrature components, as well as a wedge-shaped matrix with an inversely symmetrical sequence of elements. The amplitude-frequency characteristics (frequency response) of new synthesized I/Q-demodulators were studied. The possibility of significant suppression of the frequency response side lobes was confirmed, which confirms the noise immunity.

ABSTRACT. We present the capability of Bessel beams to establish robust wireless links in the near field with error-free, high data-rate transmission at Wband. The self-healing feature of Bessel beams is exploited to create a resilient link to opaque metallic obstructions. Such capability is first validated experimentally by placing a circular metallic obstacle within the non-diffractive region of the Bessel beam. To that end, the near field radiated by a broadband launcher consisting of a spline-profile horn is measured with and without obstacles, and the corresponding profiles compared. It appears that the Bessel-beam profile is preserved after the obstacle over the 75-105 GHz band. The robustness of the link is further validated by measuring the bit error rate (BER) of a near-field link with and without obstructions. A real-time error-free communication is reported for a data stream of 1Gb/s using an on-off keying (OOK) modulation within the non-diffractive range of the generated Bessel beams.

ABSTRACT. This article presents the conception and realization of a Flat Fabry Perot Cavity (FPC) antenna with different polarization at sub-millimeter-wave frequencies. The FPC layout is made of metallic layers and its design relies on the laser-cutting brass technique to simplify fabrication and low cost. The proposed antennas have a compact size, low fabrication cost, high gain, and wide operating bandwidth. The proposed FPC antennas are suitable for 6G Sub-Terahertz wireless communication systems.

ABSTRACT. This paper presents a cost-effective production method for high-precision, complex 3D mm-wave components and antenna prototyping. The selected manufacturing process, Laser Powder bed fusion, has been optimized for high printing resolutions. Two mm-wave (75-110GHz) structures have been designed, prototyped and characterized. These are hollow waveguide sections and an iris-based phase shifters

ABSTRACT. The principles of construction of wide-band self-controlled power limiters mm - wavelength range is proposed in the work. Methods of calculating their characteristics are provided. Ways to optimize the design are considered.

ABSTRACT. This paper presents a theoretical study of two chipless biodegradable tags which potentially can have temperature, humidity and data information. The influence of the substrate material, as well as biodegradable metalized material conductivity, are studied.

ABSTRACT. Body conformal antennas are integrated with wearable devices to sense and/or communicate with nearby devices. Many applications require to scan the surrounding environment by continuously modifying the direction of the main beam. To this end, leaky wave antennas represent an interesting cost-effective alternative to phased array due to the simplicity of feed design. This work explores different leaky-wave antenna designs in the mmWave band and investigate their performance when bent in a conformal manner. Two conformal antennas in the mmWave band are designed based on meandering microstrip line and substrate integrated waveguide. Initial results show a scanning range of -50◦ to 50◦ in the unlicensed V-Band (57-74 GHz) in the elevation direction in the conformal environment.

ABSTRACT. A new type of a semi-transparent reflectivity-based skin phantom in a form of a thin multi-layer all-dielectric structure has been designed, implemented, and tested at 60GHz. Unlike the existing analogs of volumetric human phantoms designed for SAR measurements at frequencies below 6GHz, the proposed skin phantom simultaneously allows to reproduce the complex reflection coefficient from the skin surface in the 5G mmW bands and to directly measure (or retrieve from the thermal measurements) the absorbed power density (APD), which is the main dosimetric quantity defined by ICNIRP for EM dosimetry and user exposure compliance testing of wireless devices operating in the frequency range of 6-300GHz, such as 5G and future 6G mm-wave devices.

ABSTRACT. The development of high-gain off-chip integrated metalized antennas for mmWave frequencies is strongly driven by future wireless communication and sensor applications, which require high power energy efficient array transceivers. The existing high-gain on-chip antenna solutions are too expensive for these applications due to the high cost of the chip area needed to synthesize a large antenna aperture with the desired high gain. On the other hand, metal or metalized high-gain antennas represent a promising alternative. However, they require reliable and low-loss transitions between the radiating metal structures to ICs. In this talk, we will present an off-chip integrated antenna design approach that has been recently developed at Chalmers University of Technology to maximize the overall transmitter performance (e.g. output power, efficiency, and linearity) over a relatively wide frequency band and beamsteering range.

ABSTRACT. Hyperbolic metasurfaces exhibit a lot of unique properties including negative refraction, hyperlensing, surface waves manipulation and optical sensing. In this work, we provide the practical guide of the hyperbolic metasurfaces engineering. First, we retrieve the surface conductivity of a metasurface consisting of gold nanodisks from the reflectance spectrum. Then, we analyze the dependence of the resonant wavelengths and the spectral width of hyperbolic regime on the period of metasurface and size of nanodisks. The results obtained may be used to design a hyperbolic metasurface based on gold nanoparticles for any relevant purpose on demand.

ABSTRACT. Numerical simulation of the electromagnetic field in field-forming system of different configuration and different parameters have been performed. Such a modelling was aimed on reduction of the of the degree of non-homogeneity of the magnetic induction.

ABSTRACT. The goal of this research is to investigate EM exposure on realistic inhomogeneous human models to test mobile phones in terms of electromagnetic (EM) safety. The influence of the human hand (fingers positions) during communication on the mobile phones’ antenna matching to the free space was studied through computer simulations using the Finite-Difference Time-Domain (FDTD) method at the 3700 MHz communication frequency. Dielectric heating effects caused by EMF absorption in human tissues have been considered in this paper. The obtained results are analyzed and presented below.

ABSTRACT. Some theoretical and computational results for energy-stable conformal finite element time-domain discretizations of Maxwell's system of differential equations with a cubic polarization term are presented. The focus is on energy estimates in the full range from the continuous to the semidiscrete to the fully discrete problem. In addition, an optimal estimate of the fully discrete error for the numerical approximation that is free from step size restrictions is given. Finally, some results of computer experiments are demonstrated.

ABSTRACT. The study of radiation properties of a focusing radiating system is conducted by the numerical modeling and obtaining the experimental data. The geometrical and physical parameters of system are chosen in such a way to satisfy the quasioptical conditions. The reflection and transmission coefficients are optimized in order to get the radiation in a far sone as close as possible to a desired one. The total radiation pattern (RP) is calculated as sum of the RPs of separate elements of array. The experimental data at the range of low GHz frequencies testify about the possibility to extend approach proposed for higher frequencies.

ABSTRACT. The paper discusses a numerical method for recovering a three-dimensional surface given by an implicit function, which consists in solving a three-parameter nonlinear spectral problem (NSP) for operator holomorphic function given in a Banach space. The numerical algorithm consists of solving a system of two first order differential equations in partial derivatives with some initial conditions. Numerical examples of surface recovering and solving a related approximation problems of the real positive function are given.

ABSTRACT. Ferrite antenna for receiving UWB (ultra-wide-band) electromagnetic pulses of the nanosecond duration range has been considered. The influences of the loop design, load resistance, and positions of load connection on the sensitivity of the antenna have been studied. The method of finite differences in the time domain has been used for numerical simulation. During the investigation, the loop was transformed into a cylinder with a slot covering a ferrite rod. Analysis was done for such antenna design parameters as the geometry of the loop, load resistance, and position of loads in the slot of the loop. The dispersion properties of ferrite in the form of the Debye condition of the 1st order are taken into account. It obtained regularities leading to an increase in the ferrite antenna sensitivity.

ABSTRACT. The optimal design and efficient operation of UAV detection systems require the ability to adequately predict the expected contrast values of target types of interest and their weather stability in different wavebands. This work is devoted to the experimental and theoretical study of the contrasts of various types of small UAV in the CM and MM wavelength ranges (WR) in relation to systems operating in the passive radiothermal location mode.

ABSTRACT. The paper deals with issues related to the technical possibilities of using modern ultra-wideband georadar for detecting hidden subsurface defects. Some issues related to the use of ground penetrating radars were also considered in earlier works of the authors, however, in this publication, new results obtained by the authors on the roads of Ukraine are discussed, and the development of this topic is also proposed. The corresponding proposals are based both on the achievements of modern radiophysics and on successes in related fields of science, both technical and applied. The relevance of this topic is evidenced by a significant number of publications, both those that have already become classics and modern ones. The introduction contains an overview of remote sensing methods and a brief analysis of the possibilities of using georadar for road surveys. The conclusion contains an analysis of some of the results obtained in the work and related further developments in this direction.

ABSTRACT. The perspective direction for increasing the signal constructions secrecy in radio communication systems is the use of various spectrum-spreading methods of the information signal, such as: frequency hopping spread spectrum (FHSS), direct Sequence Spread Spectrum (DSSS). One of the solutions to the problem of information security increase at the first level of the OSI reference model is possible based on signal spectrum spreading by the FHSS method. This allows to solve problems of ensuring the energy secrecy of signal constructions. Another important indicator for ensuring the information protection from unauthorized access is the strong signal constructions structural secrecy. This indicator should resist measures that are aimed at detection the form of signal structures, if the enemy has solved the problem of detecting the fact of messages transmission and interception. For increasing the structural secrecy, it is proposed to use timer signal constructions (TSC). TSC are non-positional signals. Based on TSC on the given time interval, it is possible to create larger number of signal constructions than for positional signals. In works [2-5] was given an assessment of the structural secrecy of TSC, which made it possible to conclude that it is expedient to use them in noise-protected communication systems. For this reason, it is perspective to develop methods for the formation of broadband signal-code constructions based on various signal spectrum spreading methods.

ABSTRACT. Ultra-wideband (UWB) communication achieves significantly lower power consumption compared to narrow-band technologies. However, the achievable transfer speed is much lower due to the limitations of UWB receivers. The employment of high-order pulse position modulation (PPM) in conjunction with a high-accuracy event timer at the demodulator side allows for radically increased transfer speed without compromising the power consumption. The purpose of the given paper is to present an implementation of a modular software framework and initial testbed for the exploration of high-order PPM communication which employs an event timer-based time-to-digital converter (TDC) at the receiver side. The architecture of the software framework, along with its integration with Eventech A033- ET event timer and Diglent Digital Discovery instruments, are presented. Assessment of the performance of the testbed is provided in terms of stability of the operation and bit error ratio (BER).

ABSTRACT. The problem of the underground object detection by short impulse electromagnetic wave is presented in this work. The plane electromagnetic wave is incident on the boundary between air and model of the ground normally. The electromagnetic problem of the wave propagation and its reflection on subsurface objects is solved numerically by FDTD method. The time dependences of the reflected wave received under the boundary are analyzed to detect subsurface objects. For this purpose the artificial neural network (ANN) uses the signals received in points under the boundary at fixed height. Time dependencies of received electromagnetic field is discretized with a constant time step. Additional information for the ANN is obtained by time-spatial processing that based on discrete tomography approach. The set of points presented the received time dependences is multiplied on pre-calculated time-spatial attenuation matrix. The matrix is formed on ray tracing method, antenna pattern, wave attenuation and time delays of wave in media. Underground spatial points serve as a secondary source of electromagnetic field. The work of the ANN is verified on testing data that correspond to intermediate positions of a hidden object.

ABSTRACT. The 3D vector problem of diffraction of the field of two parallel resonant impedance dipoles on a rectangular screen is solved on the base of uniform geometric diffraction theory. The software for calculating the spatial directive patterns of orthogonal field components and for determining the surface dipoles impedance providing the resonance in the normal to a screen have been developed depending on the geometrical antennas parameters. It is shown that at choosing the optimal parameters get the same width of the main lobes of the directive patterns of the orthogonal components in the main observation planes up to level of -20dB at the maximum gain in the normal to screen, the main lobe of power pattern is close to the axisymmetric one up to the level of -12dB.

ABSTRACT. The directional and polarization 3D patterns of the field of two orthogonal in-phase excited pairs of pairwise parallel impedance dipoles placed parallel to a square screen have been calculated and analyzed based on personally developed software. The radiators are considered at certain values of dipoles surface impedances providing the maximum of the square field modulus or the circularly polarized field in the normal to the screen. It is found that in the case of the circularly polarized radiator with optimal distances between dipoles and screen sizes, the spatial power patterns to relative level of –20dB and distribution of the field ellipticity coefficient have axial symmetry in the range of observation angles up to 70° and ±45°, when ellipticity coefficient is more 0.8. In the main observation planes the main lobes of the orthogonal field components patterns coincide up to 70° to relative level of –20dB and the ellipticity coefficient at the same time is 1…0.9.

ABSTRACT. The generalized method of induced electromotive forces (EMF) is used to find a solution to the problem of excitation of electromag-netic fields by a system of two monopoles with a variable surface impedance in a rectangular waveguide. The distributed surface impedance can vary along the length of the monopoles according to any predetermined law. The results of numerical and experi-mental studies of the electrodynamic characteristics of the structure under consideration are presented.

ABSTRACT. The electromagnetic (EM) wave scattering from a thin inhomogeneous film is studied using the asymptotic approach. This is possible due to small size of particles, which are embedded into inhomogeneous material of a film. The generality of approach proposed allows to investigate the scattering phenomena in the sub-THz range considering the particles of nanosize. Such particles are embedded into thin homogeneous film, and the scattering performances of resulting material are studied. The derived system of linear algebraic equation (SLAE) allows to determine the auxiliary functions, which are used to get the explicit formulas for the scattering problem. The results of numerical computations show that the scattering propertied if the designed inhomogeneous film depends on the character of the embedding nanoparticles considerably.

ABSTRACT. The eigenmodes of spheres made of materials having dispersive permittivity and permeability are calculated. The study of the eigenmodes dispersion characteristics was conducted in the frequency range where the metamaterial permittivity and permeability are negative. The effect of modes coupling was found.

ABSTRACT. In this work, computational studies of directional characteristics in the wavelength range of a waveguide-slot antenna, consisting of transverse slot radiators, having two layers of different dielectrics in the waveguide and an air gap, are carried out. A comparative analysis of the directivity characteristics for the investigated options for filling the waveguide with dielectrics is carried out under the condition of equality of the slow-wave coefficients at the central wavelength. Experimental studies of the angular frequency dependences of such an antenna have been carried out. The conditions for the optimal ratio of the dielectric permittivities of the layers, their width and mutual arrangement in the waveguide to obtain the necessary directional and energy characteristics of the array in the wavelength range are shown.

ABSTRACT. The dependence of the acceleration rate of charged particle bunches with the energy of 300 keV by a surface wave excited by a laser pulse is analyzed using planar and periodic chip structures. It is shown that when using periodic structures with the 2nd operating spatial mode, there is a decrease in the acceleration rate in comparison with the use of periodic structures with the 1st operation mode. It is also demonstrated that the acceleration rate when using a flat dielectric structure is significantly higher in comparison with a periodic chip structure.

ABSTRACT. In the paper the characteristics of electromagnetic waves reflection in samples of liquid foams of various foaming ratio were studied. The value of the foaming ratio of water foams based on water and salt additives 1-6% was in the range of 10-85 units. The measurements were carried out in the frequency range 1 - 1250 MHz in a microstrip cell using a P4-11 standing wave coefficient and attenuation meter, as well as foam structure generator based on a Schott filter. It is possible to change the characteristics of the reflection of electromagnetic waves by changing the ratio of the foam and the salinity of the foaming solution, especially in the low-frequency part of the studied wave range. Based on the foaming agents and salt additives dynamic coatings may be created with a reason to reduce the electromagnetic waves reflection from objects with metal surfaces.

ABSTRACT. The paper discusses applications of the wave analog of the Smith-Purcell effect in microwave energy compressors. It is demonstrated that both energy accumulation stage, and switching and release of accumulated energy could benefit from the realization of this effect. A whole new family of compressors featuring the wave analog of the Smith-Purcell effect is establishing, and a couple of novel compressors’ designs are presented as examples in this paper.

ABSTRACT. The problem of irradiation of the plane interface between two media by impulse electromagnetic wave is considered. The incident wave is radiated by a source in the form of a plane nonstationary electrical current. As an example, the case of uniform distribution of current and steplike time dependence is represented. Using the method of evolutionary equations the incident, reflected, and refracted waves are generated medium modal basis method is presented in form of modal expansion in a cylindrical coordinate set. Applying the boundary conditions for the fields the analytical form of the solution is obtained. The matching of the fields is carried out by the separation of the amplitude of the incident field into two parts with coefficients dependent on the material parameters of the media.

ABSTRACT. In this paper an analysis of the current state of the problem of modeling electromagnetic scattering on objects that can be located on the underlying surface and have masking covering is considered. The main steps of modeling and data processing for the electromagnetic scattering by the complex shape objects are considered. Main problems and their possible solutions are discussed. Material of this paper generalizes the results of the PhD thesis of the author.

ABSTRACT. TBA

ABSTRACT. Prof. Rashaunda Henderson (IEEE MTT-S President)

ABSTRACT. expert in European research initiatives

ABSTRACT. Distinguished Microwave Lecturer and AdCom Secretary

ABSTRACT. IEEE MTT-S – Women in Microwaves Executive Committee Member

ABSTRACT. Dr. Agnieszka Konczykowska, Fellow, Member of Editorial Board of IEEE Proc.

ABSTRACT. Young Professionals: Cerine Mokhtari (IEMN, FR) and Malgorzata Warecka (GUT, PL)

ABSTRACT. Two different modifications of the integral equation technique are presented for correct modeling of the plane electromagnetic wave scattering by flat grating of finite number of impedance strips. The first modification is reworked to examine the plane E-polarized wave scattering problem. The second modification is reworked to studying of the plane H-polarized wave scattering problem. These modifications give the possibility to rework full-wave flat impedance strips gratings theory. Considerable attention is focused on asymptotic models of the plane EM wave scattering by sparsely filled pre-fractal strip grating. In that case corresponding integral equations’ systems have explicit solutions. Scattered electromagnetic field in the far-zone can be successfully analyzed on the base of the asymptotic electrically narrow strip models.

ABSTRACT. The purpose of this paper is to compare thin-wire and surface modeling techniques in MoM solution of radiation and scattering problems on microwave antennas with linear and mixed mesh geometries. This is done for two various feed schemes proposed for surface and wire models. The proposed approach is applied to analyzing canonical antenna geometries with linear elements.

ABSTRACT. In this paper, one of the possible methods for the approximate solution of the plane electromagnetic wave diffraction problem by the perfectly conducting sphere is discussed. The method assumes the representation of the solution by the minimal number of the zero order spherical Hankel functions. Their singularity points, in this case, must be located equidistantly along the axis of incident wave propagation. The presented numerical results confirm the validity of this method

ABSTRACT. The present study investigates electromagnetic plane wave diffraction by a strip with two different surface impedances on both sides. On the strip, the Leontovich boundary conditions are satisfied on each surface. Then, the solution is obtained by the analytical-numerical method called orthogonal polynomials. The numerical results are analyzed with the fractional derivative method. The paper answers how to build up the mathematical background of the problem and provides near electric field distribution for different cases.

ABSTRACT. The resonant phenomena arising from the incidence of electromagnetic radiation on the cylinder are investigated. The case when a plane wave is incident on an infinitely long circular cylinder is considered. Resonances arise at certain ratios between the cylinder diameter D and the radiation wavelength . In thick refractive cylinders with absorption (D >> ) resonances are associated with the appearance of a wave that propagates along the surface of the cylinder, but at some points passes inside it. Scattering and absorption increase at resonance. Fano resonances arise in thin cylinders with a high refractive index. At some values of the cylinder diameter, its interaction with the wave is enhanced (resonance), at other values, the "anti-resonance" is weakened. The distribution of the field in the cylinder and its vicinity and the scattering diagram in these cases are calculated. It is the same as that of a dipole at resonance. With "anti-resonance" the shape of the scattering diagram is close to circular, and the intensity of the scattered radiation is hundreds of times less. The cylinder becomes invisible.

ABSTRACT. The proposed paper aims to investigate the possible harmful effects of EMFs used in 5G systems on the most important insect, a honey bee. The expected hazardous impact will lead to the disturbance of balance in certain bio-systems and also a food crisis. As it is well known, the plants on the planet are mainly pollinated by honeybees and other insects. A significant reduction of pollinators will lead to harvest failure. Therefore, 5G systems might significantly damage the life cycle of insects, and this will lead to the destruction of the food chain. This will have an extremely large negative effect on humans. In the presented study, the dielectric heating effect caused by EMFs was studied on honey bees from 2.5 GHz to 100 GHz by the Finite Difference Time Domain (FDTD) method. A discrete, 3-tissue honey bee model was used for FDTD modeling, and a new approach for the selection of tissues' EM parameters was introduced. The SAR peak values were evaluated for honey bee tissues. The obtained results showed the possible harmful effects at some frequencies, depending on the direction of the incident EM wave and E-field polarization.

ABSTRACT. Numerical simulation of non-uniform profile retrieval of rain intensity was performed for operating wavelengths 0.82 and 3.2 cm and for different values of measurement errors of received powers and total attenuation. Retrieval method uses the Tikhonov regularization for solution of the integral equation of scattering and inverse iteration procedure for taking into account the signal attenuation. It is shown that proposed method provides the acceptable retrieval error (maximum is less than 40 %) for intensity more than 3 mm/h.

ABSTRACT. The possibility and peculiarities of developing a method and creating a device for remote detection of explosive objects are considered. The proposed device is an active-passive radar consisting of active and passive channels operating on common antenna. The features, advantages and drawbacks of the proposed device are noted in comparison with traditional radar.

ABSTRACT. The work substantiates the expediency of developing methods for thematic processing of multispectral images obtained from space or unmanned aerial vehicles. A method of a color combination selecting in the channels of the processed Image for the synthesis of an image with false colors is proposed. This approach based on the combined using of: color contrast method (the method of false colors) as it is, the commercial software "ENVI" and the developed software "Deciphering Atlas". The methodology involves the construction of a deciphering atlas for a specific sensor, installed on spacecraft or unmanned aerial vehicle. The proposed approach makes it possible to speed up the processing of multispectral images.

ABSTRACT. Detection of multiple targets in high dynamic range and noise varying environment is a great challenge of modern radar techniques. Traditional CFAR algorithms cannot provide reliable detection of all targets in such sophisticated environment. To overcome this drawback we propose detector with iterative thresholding of frequency samples relative standard deviation. Applying proposed approach will ensure reliable detection of multiple targets regardless of noise power and dynamic range of signals.

ABSTRACT. We analysed the multiharmonic interactions of space charge waves in the amplification section of the superheterodyne free electron laser in the submillimeter wavelength range within the framework of the cubic nonlinear approximation. We use an undulator with a longitudinal periodic reverse electrostatic field to amplify longitudinal waves. We researched the effect of generating an additional periodic reverse pump electric field by an electron beam. We demonstrate that the device can amplify multiharmonic signals without distorting of their amplitude spectra. With the given input parameters of the considering FEL, we found the feasible in practice values of the saturation length and level of the amplification of a terahertz signal. Also, for the first time, we studied the effect of generating an additional electric pump field due to the electron bunching in a relativistic electron beam in a linear approximation. We show that the resulting pump electric field increases by 33% due to this effect. This leads to an increase in the growth rate of space charge waves and a decrease in the saturation length by ~33%.

ABSTRACT. Spectra of capillary waves of distilled water and NADH solution in distilled water and their dynamics under the influence of electromagnetic radiation in the gigahertz range were studied. An analysis of the relationship between the temporal and spatial frequency of capillary waves on the surface of a low-viscosity liquid was carried out, which made it possible to use the non-destructive method of optical heterodyning to determine the rheological characteristics of the near-surface layers of the samples. Irradiation of distilled water with electromagnetic radiation (specific power 10-4 W/cm2, frequency 60 GHz, exposure time 1 - 20 min.) leads to an increase in the viscosity and surface tension of the NADH solution in the distillate leads to a decrease in its viscosity and surface tension, which indicates changes in conformations of NADH molecules.

ABSTRACT. A long-wave generalization of the effective permittivity and permeability tensors for the Polder-van Santen approximation for a 3-D two-component composite are presented in this study in terms of electric and magnetic polarizabilities. The composite is a cubic array of spherical particles imbedded in homogenous dielectric host medium. A specific representation of the particle polarizabilities allow to take into account the radiation loss. The case of fully magnetized material of particles is considered in the study. The obtained expressions of the Effective Medium Theory for composite under the consideration have shown to agree well with rigorous but complicate analytical theory obtained earlier for subwavelength ranges defined by the dimension of unit cell.