Sergey Shabunin

Ural Federal University | UrFU

The main problem of phased antenna arrays with element-by-element phasing is the complexity of the beamforming network, as well as additional loss at each phase shifter. An increase of the clustering degree leads to a simplification of the beamforming network and to a decrease in loss due to the use of a smaller number of phase shifters. However, a...

The power absorbed by human head tissues in the microwave range is investigated. Calculation of the electric field induced in the head tissues by antenna probe is based on the use of the Green’s functions of the stratified media. Two types of emitters such as a half-wave dipole and a loop antenna are compared in terms of the depth of electromagneti...

When designing the millimeter-wave antennas, for example, for the automotive radars, the problem of choosing the polarization of radiation arises. Polarization does not matter for microstrip antennas radiating along the normal. But for the antennas that form a scanning beam, (for example, phased arrays or active phased arrays) the choice of the typ...

An antenna array for remote determination of the wind direction and speed is considered. The problem of optimal clustering of the antenna array with the triangular grid of radiating elements is solved. The directions of preferred radiation with a minimum level of the side lobes are determined. The number of radar receivers and transmitters is minim...

In this paper, we consider the change in the directional pattern of a microstrip patch antenna located on a perfectly conducting plane and a cylinder covered with a dielectric layer. The mathematical apparatus of the Green’s tensor functions for flat and cylindrical layered metaldielectric structures is used to calculate field characteristics. The...

The development of the Internet of Things and communication systems of the fifth generation leads to the need to place many antenna elements in a limited volume. Therefore, wearable electronics antennas are often located directly on the device body. Such surfaces can often be thought of as a conducting cylinder covered with a dielectric material. T...

Currently, radar and radionavigation systems for aerological sounding of the atmosphere with the help of aerological radiosondes launched into the atmosphere are widely used to provide operational weather and climate forecasts. Meteorological radar systems for various purposes have been developed to obtain operational data on the free atmosphere. T...

Изложены основы теории электромагнитных волн, рассмотрены особенности распространения волн в различных средах и электромагнитных волн на границе раздела сред. Проанализированы основные направляющие системы и их собственные волны, объемные резонаторы на их основе, а также закономерности электромагнитного поля внутри них. Приводятся способы расчета и...

The paper considers application of the Green’s tensor functions to analysis of the multilayer magneto-dielectric structures in relation to photonic crystals of the microwave range. The solution of the problem of electromagnetic wave propagation in rectangular and flat waveguides, as well as in unlimited space is presented. Efficiency of application...

The Green’s functions of layered structures are used for analysis of measurement errors of transmitting losses through solid and sandwich-type dielectric structure. Influence of the spherical waves excited by radiators in the near zone is under investigation. As the simplest antenna, the Huygens element was used for calculations. The model of equiv...

The method of Green’s functions for layered cylindrical magneto-dielectric structures is applied to solution of radiation, propagation and scattering problems. Excitation of an electromagnetic field is provided by arbitrary distribution of impressed electric and magnetic currents. The model of equivalent circuits is used for the description of a la...

Radiation of antennas under electrically large hemispherical and geodetic antenna covers is considered. The Green’s functions for layered structures are used for reflection and transmission electric field calculation. The reflected and transmitted electromagnetic field is calculated as radiation of the equivalent electric and magnetic currents on t...

The parameters of radar antenna systems constructed according to the traditional scheme with phase shifters inserted both in the transmitting and receiving antenna array with the radar in which signal processing is performed only on the receiving side are considered and compared in the paper. In the second case, an additional requirement of orthogo...

The influence of the interaction effects of the transmitting and receiving antennas of a mil-limeter-range radar, as well as the direct transmission of the transmitter signal to the receiver input via the internal circuits of the microwave chip on the level of the decorrelated phase noise is under consideration. It is shown that for a certain amoun...

The use of radars with phased antenna arrays in aerological atmospheric sounding systems significantly increases the technical characteristics of the radio channel, ensures reliable auto-tracking in the near zone at high angular velocities of the aerological probe, and reduces the overall dimensions of the radar station. Modelling and optimization...

Antenna arrays with beam scanning are composed of phase shifters. With a large number of elements, the phase shifter control current can be very large. In particular cases, at fixed angles of beam orientation, the control current can be minimized by introducing an additional phase shift to all elements of the antenna array. The article analyzes the...

Electromagnetic wave scattering by perfect electric conductor convex bodies of revolution is under consideration. Physical optics approach is applied to obtain a numerical solution of a surface integral. A mesh generation method of a body of revolution described by only the equation of a curve is suggested. The surface current density is defined on...

The radiation characteristics of leaky-wave antennas located on the curvilinear cylindrical surfaces are considered. The phase distributions are shown that take into account the propagation of the wave inside the curvilinear guide structure and the spatial path of the rays from the antenna surface to the equivalent wave front. A solution is given f...

Methods of constructing antenna arrays having a narrow beam width while providing a low level of si de lobes are analyzed in the article. The patterns and the geometric dimensions of the antenna arrays based on patch antennas as radiating elements are presented. The method of constructing narrow beam antenna arrays, which solves the problem of too...

Luneburg lens antenna radiation fields are calculated with Green's functions of spherical and cylindrical layered structures. Electric field components of spherical and cylindrical Luneburg lenses excited by linear and circular polarized incident field are analysed. Dipole, slot and aperture antennas are described by electric and magnetic extraneou...

Luneburg lens antenna radiation field is calculated with Green's functions of a layered cylindrical structure. Electric field components of Luneburg lens excited by electric and magnetic dipoles, Huygens source and a circularly polarized antenna formed by two crossed electric dipoles with 90-degree phase shift are considered. Electric field calcula...

A leaky-wave antenna based on two-layer substrate integrated waveguide with transverse slots and protective dielectric cover is investigated. A dispersion equation, that allows finding the complex propagation constant in the structure, is obtained. Velocity factor dependencies on the position of slots, protective cover permittivity and filling fact...

Luneburg lens antenna radiation fields are calculated with Green's functions of spherical and cylindrical layered structures. Electric field components for Luneburg lenses excited by a linear and circular polarized antenna are analyzed. Co-polarized and cross-polarized field radiation patterns are shown. Reflection from the lens, losses in the lens...

A leaky-wave antenna based on a partially filled rectangular waveguide with long slit on narrow wall is investigated. Velocity factor dependencies for different slit widths are presented. Also, dielectric layer thickness variations are considered. The influence of protective cover thickness and the dielectric layer position inside the waveguide on...

A leaky-wave antenna based on a rectangular waveguide with partially dielectric filling and long slit on the narrow wall is investigated. The Green's function method for dispersion equations and antenna radiation analysis is suggested. A protective dielectric cover on the screen with slit is taken into account. A complex propagation constant is def...

Lowering antenna gain, sidelobes growing, boresight errors and depolarization field of aperture antennas and antenna arrays caused by radomes are under consideration. Transmission and reflection of electromagnetic waves by sandwich type antenna radomes are analyzed. The Green's functions of layered structures and equivalent currents are used for el...

A leaky-wave antenna based on a rectangular waveguide with partially dielectric filling and transverse slots is investigated. A velocity factor dependencies for uniform filling and different slot lengths are presented. Also, dielectric layer thickness variations are considered. The influence of the dielectric layer position in the waveguide on the...

A Leaky-wave antenna based on a rectangular waveguide with partially dielectric filling and transverse slots is investigated. The Green's function method for dispersion equations and antenna radiation analysis is suggested. A protective dielectric cover on the screen with slots is taken into account. The complex propagation constant is defined by m...

A leaky-wave antenna based on a rectangular waveguide with partially dielectric filling and transverse slots, is studied. The Green's function method for dispersion equations and antenna radiation analysis is suggested. A protective dielectric cover on the screen with slots is taken into account. The complex propagation constant is defined by match...

The method of Green's functions of layered cylindrical magnetodielectric structures with arbitrary extraneous electric and magnetic currents using an equivalent lines approach is briefly described. Transmitting matrices and different kind of loads are used for a layered structure and space boundaries modelling. Equivalent voltages and currents in a...

J. A. Stratton and L. J. Chu were the first scientists who solved an antenna problem with radiation of a ring slot on a conducting sphere [1]. It was almost seventy years ago. There were some inconveniences in that solution. Firstly, the slot width was not taken into consideration so a reactive part of radiation admittance was not defined. Secondly...

Spectral-domain full-wave approach for cylindrical radially non-uniform structures based on the matrix technique is described. Scattering properties of a circular conducting cylinder coated with a layered material are investigated analytically. The behavior of the scattered field in the far zone is illustrated with numerical results for different c...

The Green's functions of grounded magnetodielectric slab using alternative wave expansion with LE, LM waves are suggested. Radiation patterns of surface waves excited by a patch dipole and a slot covered with double-positive and double-negative permittivity and permeability media are obtained and compared. The space wave radiation efficiency for a...

A new kind of subwavelength antenna as coaxial line open-end embedded in hemispherical core-shell system is analyzed. The opportunity of an efficient directive radiator design theoretically and numerically is proved

The Green's functions of grounded magnetodielectric slabs with LE, LM waves' expansion and layered circular cylinder with E, H waves' expansion are used for surface and space waves analysis. Traditional magnetodielectrics and double negative materials are under consideration. Radiation patterns of surface waves excited by a slot covered with double...

The Green's functions of grounded magnetodielectric slabs using the alternative wave expansion with LE, LM waves are suggested. Radiation patterns of surface waves excited by a patch dipole and a slot covered with double-positive and double- negative permittivity and permeability media are obtained and compared. The space wave radiation efficiency...

Linear and circular polarized waves scattering on spherical homogeneous and layered bodies with negative refraction index are studied. The wave excitation and diffraction analysis is based on a new universal representation of Green's tensors for composite spherical bodies. Scattering waves' behaviour is analyzed.

The Green¿s functions of grounded magnetodielectric slab using alternative wave expansion with LE, LM waves are suggested. Electric components of surface waves excited by patch dipole and a slot covered with double-positive and double-negative permittivity and permeability media are obtained. Space wave radiation efficiency and surface wave radiat...

Two antenna arrays with linear and circular polarization for meteorological radiosonde tracking radar are compared and discussed. The 26 dB gain antenna operates in 1.765-1.795 GHz range. Both arrays consist of four subarrays. Each subarray comprises suspended rectangular patch antennas fed by air filled strip lines. The 4 element array incorporate...

The four-element stacked patch antenna array on conducting cylinder is reported. Multilayered dielectric structure is analyzed using the equivalent transmission line model for two coupled lines with E and H waves. The problem of the patch antenna design with expanded bandwidth is solved. Radiation patterns and VSWR variation are shown.

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The effectiveness of the tensor Green function method is shown by B.A. Panchenko et al for calculation of the characteristics of strip and slot antennas with a dielectric layer. Selection of the Green function representation for an expansion in terms of the LE and LM wave modes made it possible to simplify the computational operations appreciably,...

The approach of Felsen and Markuvitz (1978) is used to obtain expressions making it possible to extend the method of Green tensor functions to media with a relative magnetic permeability not equal to unity. This approach makes it possible to calculate the propagation constants of shielded or unshielded striplines as well as to investigate radiation...

The Green function is used to analyze a ring antenna on a conducting cylinder with a dielectric layer. This approach makes possible a full investigation of all the field, energy, and impedance characteristics of microstrip wraparound antennas. The dependence of the spatial-wave pattern of the antenna on the parameters of the dielectric coating of t...

A method is developed for calculating the radiation efficiency of microstrip antennas with allowance for power losses connected with surface-wave excitation, cross-polarization losses, and heat losses in the dielectric substrate and metal of the radiators and shield. Calculation results are presented for various values of the geometric dimensions o...

An electrodynamically substantiated method, based on Oliner's (1956) approach, is proposed for calculating radiation from the open end of a microstrip line. A Green-function representation for field expansion in LE and LM modes makes possible a simple evaluation of the relationship between the powers of bulk and surfaces waves. A comparison of calc...

Based on expansion of fields in terms of LE and LM waves, expressions are obtained for the transmission of radiation by a narrow rectangular slit in a shield covered with a dielectric layer. The contribution of surface and spatial waves to the conductivity is investigated. The radiation patterns of a slit emitter are determined.

The Green-function representation with the expansion of the field in LE and LM modes is used to derive expressions for calculating the field and impedance characteristics of radiation from a narrow rectangular slot in a screen coated with a dielectric layer. The contributions of surface and bulk waves are analyzed, and the radiation patterns of the...

Using tensor-type Green functions, the expressions are obtained for radiation impedances of a microstrip line with arbitrary nonuniformity. Directional patterns of the LE- and LM-type waves are presented.

Expressions for the radiation resistance of bulk and surface waves in a stripline with arbitrary inhomogeneity are obtained using the Green tensor functions for LE and LM mode expansions. Radiation patterns are presented, and an analysis is presented of the efficiency of a stripline with an HF-power channeling device as the inhomogeneity