2002, volume 7, special issue

TO THE HISTORY OF LINEAR ACCELERATORS IN KHARKOV

Khizhnyak A. N., Ranyuk Y. N., Dovbnya A. N., Egorov A. M.

175-177

Reviewed is the history of the first USSR program of development of linear accelerators of protons in 1940-50’s. These accelerators were proposed as a non-conventional air-defense weapon. Kharkov Institute of Physics and Technology played important role in this early research program.

A FINE STRUCTURE OF THE ELECTROMAGNETIC WAVE RESONANCE IN A DIELECTRIC SPHERE

Bryzgalov G. A., Khizhnyak N. A

178-182

In the last few years, the works appeared in which the models of artificial dielectrics were discussed having in the frequency band negative values of both dielectric permittivity and magnetic permeability. As shown in [3], electromagnetic wave propagation in such media was characterized by the peculiarities important to understand the electromagnetic radiation interaction with tissues in vivo. The aim of this work is to show that such media in organic nature occurs very often, and the mechanism of formation of simultaneous negative values of  and  is already contained in their physical structures. Moreover, experimental results are known that confirm the existence of positive and negative values of  and  in a narrow frequency band. This fact is not totally clear until recent times.

THE SCATTERING OF ELECTROMAGNETIC WAVES IN A WAVEGUIDE WITH THE HOMOGENEOUS MAGNITODIELECTRIC SPHERES

Kozar A. I.

183-189

Solution of the problem about the scattering of electromagnetic waves on the arbitrary little number of small resonant spheres in A rectangular waveguide is considered. The expressions for the scattered waves are derived.

THE PROBLEM OF DIFRACTION IN . THE PERIODIC SOLUTIONS

V. A. Shcherbina

190-195

A boundary pseudo-differential equation has been constructed for natural electromagnetic waves in periodic corrugated waveguides in the 2-dimensional space.

NEW NUMERICAL-ANALYTICAL METHOD FOR THE WAVE ANALYSIS OF COAXIAL GYROTRON

Gandel Y. V., Zaginaylov G. I., Steshenko S. A.

196-203

A new approach to the solution of spectral problem for gyrotron with longitudinal corrugations is developed. This approach is based on strict statement of boundary value problem for Maxwell  equations, its reducing to singular integral equation, which is numerically analysed with use of interpolational quadrature formulas. The offered method is applicable in any frequency band for arbitrary size corrugations.

A DIELEKTRIC RESONANT ELLIPSOID IN A HORN RADIATOR

Ukrainets N. I.

204-207

The results of experimental investigation of the electromagnetic waves scattering by a dielectric resonant ellipsoid placed in a horn radiator are presented. The twin resonances of reflection and passage are discovered. Their properties are analyzed.

LOW-FREQUENCY APPROXIMATION FOR THE PROBLEM OF ELECTROMAGNETIC WAVE PROPAGATION IN A DOUBLY- PERIODIC MAGNETODIELECTRIC LAYER

Sidorchuk N. V., Yachin V. V, Prosvirnin S. L.

208-212

The scattering problem is solved for a plane electromagnetic wave incident obliquely on a doubly-periodic magnetodielectric layer bounded by two homogeneous media. The problem of determination of layer eigenmodes is investigated in the low-frequency range. The Galerkin technique is used to obtain the boundary problem for the set of linear differential equations with constant coefficients and, consequently, to determine amplitudes of scattered waves.

FRESNEL’S FORMULAE IN TIME DOMAIN

Nerukh A. G

213-217

Time-spatial representation of Fresnel’s formulae is obtained. It allows describing an interaction of complex time-spatial electromagnetic signals with a plane interface of dielectric media and contains a case when the interface itself is non-stationary, for example, it is created at some moment of time. Such a description is made by virtue of integral equations.

ON PROBLEM OF WAVE PROPAGATION AND TRANSFORMATION IN MHD MEDIUM

Alexandrova A. A., Alexandrov Y. N.

218-223

On the basis of the fundamental solution of system of the linear differential equations of magnetic hydrodynamics in motion medium and the extinction theorem of MHD interpretation the linear transformation of MHD waves on the discontinuities surface is analyzed.

ON SOLVING THE PROBLEMS OF ELECTROMAGNETICS IN TRANSIENT MEDIA: DIFFERENT APPROACHES BASED ON INTEGRAL EQUATION

Vorgul I. Yu, Vorgul A. V.

224-228

Different approaches to solving the problems on electromagnetic field transformation in media with time-dependent parameters are proposed. They are based on rigorous or approximate solutions of integral equation for field in such media, being illustrated by the sample cases of different temporal variations of medium conductivity.

EXCITATION OF A SYSTEM OF MUTUALLY PERPENDICULAR WIRE ANTENNAS

Yatsenko E. A., Yatsenko N. M.

229-233

A problem on excitation of currents and definition of fields of radiation in a far zone far a system which consists of two PEC linear wire antennas located mutually perpendicularly in one plane without being crossed was solved by method of the integral equations. The formulas for currents in each wire antenna are obtained in view of their mutual influence, the fields and power of radiation in a distant zone are determined.

A MODEL OF COUPLED OSCILLATORS IN THE THEORY OF LAYERED DIELECTRIC

Ayzatsky M. I., Kramarenko K. Yu.

234-239

The possibility to use a model of coupled oscillators for description of the dispersion characteristics of layered dielectric structures is shown. The model gives an opportunity to make an approximate analysis of various multi-layered structures. Here the possibility of making physical analysis of the results still exists.

A SCATTERING FROM THE SLOTS IN A WAVEGUIDE FILLED WITH A LOSSY DIELECTRIC

Yatsuk L. P., Nazarenko T. G.

240-246

The problems of theory of narrow slots in walls of a waveguide filled with lossy dielectric are under consideration. The power balance equation has been formulated. For the longitudinal and transverse slots in a rectangular waveguide the reflection, transfer, radiation coefficients and the part of power consumed for  dielectric heating have been investigated. It is shown that the higher-mode waves make a considerable contribution into Ohm's losses which are much greater for a longitudinal slot then for a transverse one.

TWO-DIMENSIONAL SCATTERING OF H-WAVE BY A DIELECTRIC LOADED SEMI-CIRCULAR TROUGH IN A GROUND PLANE

Tyzhnenko O. G.

247-253

Two-dimensional problem for an H-polarized plane wave scattering by a dielectric loaded semi-circular groove in a ground plane is solved in the full-wave formulation. The Reyleigh series and the partial orthogonality of trigonometric functions were used while solution. As a result, a Fredholm infinite set of algebraic equations for Fourier coefficients is obtained. The uniqueness of the solution of this set is proved. The convergence rate is estimated. The obtained solution is compared with the known solution, which was obtained by another method. A good agreement of solutions gives an evidence of adequacy of proposed method. A lossy dielectric is considered and an effect of significant backscattering reduction is reviealed for oblique incidence even.

NUMERICAL MODELING OF A 2-D ELLIPTIC DIELECTRIC LENS USED FOR IMPROVEMENT OF DIRECTIONALITY OF AN APERTURE SOURCE

Boriskin A. V.

254-258

The effect of a localized light source directivity improvement due to an elliptic shaped dielectric cylinder taken as a 2-d model of a dielectric lens is studied. the source is simulated by the field of a complex source-point (csp). an efficient algorithm for the solution of 2d problem of wave scattering by a smooth dielectric cylinder is developed, based on the concept of analytical regularization. basic properties of the algorithm are studied. numerical results for the accuracy of the algorithm and sample far-field characteristics such as, directivity and radiation patterns for various lens parameters are presented.

RADIATION OF A SPHERICAL DISK MICROSTRIP ANTENNA EXCITED BY A SLOT

Radchenko V. V.

259-267

In this paper, the problem of radiation of antenna excited by a slot on the surface of partially screened dielectric-coated metal sphere is considered. The slot is simulated by an elementary tangential magnetic dipole. The presented approach enables one to analyze the basic antenna characteristics in full-wave manner. The analytical regularization method can be considered as numerically exact one because, within the formulated model: 1) the accessible accuracy is limited only by the computer precision, and 2) the accuracy is uniform with respect to parameters, even in the resonances. Due to analytical inversion of the singular part of the problem, the resulting algorithm is very efficient. Numerical results for all basic antenna characteristics are demonstrated.

SOME PROPERTIES OF A VIDEOPULSE SCATTERING BY GROUND SLABS WITH CONTINUOUS SPATIAL VARIATION OF FREQUENCY-DEPENDENT ELECTRIC CHARACTERISTICS

Puzanov O. O.

268-276

The properties of nonsinusoidal radio waves scattering by natural ground slabs with a complex law of spatial variation of frequency-dependent electric characteristics has been considered, transients for aeration zones with typical laws of humidity variation are analyzed. Insufficiency of some experimental data (measured in a wide frequency band) describing electrical properties of natural media for numerical modeling the geo-radar outgoing signal scattering by ground slabs has been established.

TEM‑FIELD CALCULATION FOR WAVEGUIDES WITH COMPLICATED CROSS-SECTIONS.

Kulik D. Yu, Tkachenko V. I., Senkevich S. L.

277-284

The main goal of the paper is to present a mode-matching based algorithm of TEM-wave field calculation for waveguides with arbitrary piecewise-linear Cartesian boundary cross-section.

ANALYSIS AND OPTIMIZATION OF THE BIFREQUENCY TURNSTILE OF RADIATORS WITH IMPEDANCE ELEMENTS

Ovsyanikov V. V., Reuta A. V., Beznosova E. R.

285-287

The results of calculation of radiation characteristics and input resistances the bifrequency dipole turnstile antenna by methods of an equivalent long line and integral equations are presented. The example turnstile array antenna from four vibrators with impedance elements is shown.

THE NONSPECULAR WAVE REFLECTION FROM A SCREENED CHIRAL LAYER WITH A DIFFRACTION GRATING

Panin S. B.

289-293

In the paper, wave polarization conversion is studied when a plane electromagnetic wave is nonspecularly reflected from the structure as a succession of layers in the order: strip grating, dielectric layer, chiral layer, and screen. The corresponding diffraction vector problem has been solved using the analytical regularization procedure, and the so obtained solution allows effective numerical treatment of the process. The autocollimation reflection and the nonspecular reflection with lager telescopicity coefficient have been found, when they proceed at the quasi total conversion of the plane-polarized incident wave into the space harmonic, whose polarization plane is normal to the incident wave polarization.