Begell House
Telecommunications and Radio Engineering
Telecommunications and Radio Engineering
0040-2508
51
2-3
1997
WAVE PROPAGATION AND SCATTERINGExperimental Investigation of Microwave -Frequency Radar Signals Scattered by the Sea Surface
The problem of rejecting the interference of natural origin in high potential radar complexes operating over the sea is of great practical importance. Radar returns from the rough sea account for the major share of the interference, along with meteorological factors, angel clutter and birds. The scattering occurs from various ranges at all grazing angles and can be observed over a wide frequency range. This article presents the results of research of sea clutter carried out in the Institute of Radiophysics and Electronics, National Academy of Sciences of Ukraine for over 20 years. The research concerns the most interesting range of small grazing angles which are characteristic of most of ship and borne coastal radars. The main attention is given to the experimental study of the parameters of radio signals reflected from the sea surface, such as the specific radar cross-section and spectral characteristics. The results obtained are discussed in terms of the known theories and compared with the data of other writers. The measurements were carried out with prototypes of high potential radars at the wavelengths from 3.2 cm to 2 m on the Black Sea coast (towns of Gelendzhik and Sudak). In a number of cases parallel measurements of the sea roughness and wind characteristics were performed, as well as meteorological measurements in the lower layer of the troposphere.
I. D.
Gontar
A. Usikov Institute of Radio Physics and Electronics, National Academy of Sciences of Ukraine, 12, Academician Proskura Str., Kharkiv 61085
F. V.
Kivva
A. Usikov Institute of Radio Physics and Electronics, National Academy of Sciences of Ukraine, 12, Academician Proskura St., Kharkov 61085
V. Yu.
Ryazantsev
V. B.
Sinitski
A. Usikov Institute of Radio Physics and Electronics, National Academy of Sciences of Ukraine
Ivan S.
Turgenev
A. Usikov Institute of Radio Physics and Electronics, National Academy of Sciences of Ukraine 12, Academician Proskura St., Kharkov 61085, Ukraine
Stanislav I.
Khomenko
A. Usikov Institute of Radio Physics and Electronics, National Academy of Sciences of Ukraine
1-24
Microwave Scattering From the Sea Surface
G. P.
Kulemin
A. Usikov Institute of Radio Physics and Electronics, National Academy of Sciences of Ukraine, 12, Academician Proskura St., Kharkov 61085
V. I.
Lutsenko
A. Usikov Institute of Radio Physics and Electronics, National Academy of Sciences of Ukraine, 12, Academician Proskura St., Kharkov 61085
25-45
Multipath Propagation of the Microwave Above Sea Surface
V. B.
Razskazovsky
A. Usikov Institute of Radio Physics and Electronics, National Academy of Sciences of Ukraine
Yu. F.
Logvinov
A. Usikov Institute of Radio Physics and Electronics, National Academy of Sciences of Ukraine
46-65
Sea Ice Microwave Thermal Radiation Characteristics
An increased snow cover influence on the 8 millimeter-band radiation of sea ice (compared with that of centimeter band) was the reason for additional research of sea ice radiothermal properties. Such investigations (that help to study sea ice distributions) are carried out at the Usikov IRE of the NAS of Ukraine by means of «Analog» airborne radiophysical sounding system. Calculations as well as an experiment performed in a point under the flight path of the system, in a perennial ice area of the eastern sector of Arctic basin, have shown the following: 0.5m thick snow-and-firn cover substitutes considerably the ice 8mm-band radiation for its own radiation (a colder one) producing a masking effect; in the case of small snow thicknesses, another possible source of the spatial fluctuations of perennial ice radiation should be taken into account, the source being connected with the presence, on the ice surface, frozen freshwater «puddles» whose radiothermal temperature is higher than that of the ice.
Yu. I.
Malyshenko
A. Usikov Institute of Radio Physics and Electronics, National Academy of Sciences of Ukraine, 12, Academician Proskura St., Kharkov 61085
V. A.
Komyak
A. Usikov Institute of Radio Physics and Electronics, National Academy of Sciences of Ukraine, 12, Academician Proskura St.,61085 Kharkov
66-72
Bistatic HF radar for oceanography applications with the use of both ground and space waves
Ivan S.
Turgenev
A. Usikov Institute of Radio Physics and Electronics, National Academy of Sciences of Ukraine 12, Academician Proskura St., Kharkov 61085, Ukraine
Pavel A.
Melyanovcky
A. Usikov Institute of Radio Physics and Electronics, National Academy of Sciences of Ukraine 12, Academician Proskura St., Kharkov 61085, Ukraine
73-80
Measuring of Millimeter Wavelength Scattering Characteristics of Diffuse Objects
81-84
Radio Meteorological Parameters Determining Microwave Radio Propagation over the Ocean and their Measurement Techniques
The data of refractive index measurements are used to calculate the heights H0 and "M- deficits" of surface ducts over the sea, as well as structure constants CN, and axial ratio α of refractive index inhomogeneities determining the attenuation of microwave signals propagating over the sea surface. The variability of these parameters with the geographic region and year season is estimated.
The possibility of estimating these radio meteorological parameters from the data of standard hydro-meteorological measurements has been tested using the Monin-Obukhov theory for the atmospheric boundary layer. It is shown that the results of such calculations reasonably correlate with the refractometry data, (the axial ratio α except), in the case ωηεν the universal constant αe of the Monin-Obukhov theory is equal to 300.
M. V.
Belobrova
A. Usikov Institute of Radio Physics and Electronics, National Academy of Sciences of Ukraine
V. K.
Ivanov
A. Usikov Institute of Radio Physics and Electronics, National Academy of Sciences of Ukraine, 12, Academician Proskura Str., Kharkiv 61085, Ukraine
A. N.
Koshel
I. E.
Ostrovsky
I. M.
Fuks
University of Colorado/CIRES and NOAA/ERL/ETL 325, Broadway, Boulder, CO 80305-3328, USA
85-92
Waves in Magnetized Dusty and Self-Gravitational Plasmas
Among the external fields acting upon dusty plasmas, magnetic fields stand out. The behavior of dusty and self-gravitational plasmas placed in a magnetic field is given special consideration. The dielectric constant tensor for the self-gravitational magnetized plasma is derived and the eigenwave spectrum analyzed. If the spectrum of grain sizes (masses) is continuous, then anomalous dispersion is observed and the right circular polarized electromagnetic wave is attenuated owing to the dust- cyclotron absorption. In the case of the discrete mass spectrum the bicomponent medium consisting of two grain species, i.e. heavy- and light-weight, is considered. Even this oversimplified model shows quite a number of unusual properties, like an Alfv'en wave with a frequency dependent phase velocity, a new low frequency mode and substantially new conditions for the appearance of hybrid resonances.
Victoria V.
Yaroshenko
93-102
MICROWAVE ELECTRODYNAMICSNumerical Analysis of Surface-Wave Filters Based on a Whispering-Gallery-Mode Dielectric Resonator and a Slitted Metal Cavity
C. V.
Boriskina
V. Karazin National University of Kharkov, 4, Svoboda sq., Kharkov, 61077
Alexander I.
Nosich
A. Usikov Institute of Radio Physics and Electronics, National Academy of Sciences of Ukraine 12, Academician Proskura St., Kharkov 61085
103-111
An Efficient Algorithm for Analizing a WaveguideA Bifurcated by a Thin Semi-Infinite Plate and Its Application to the Design of Millimeter Bandpass Filters
An efficient algorithm is proposed to calculate the generalized scattering matrix in the case of a semi-infinite thin plate placed within the E-plane of a rectangular waveguide. It is based on the moment method for solving the integral Fredholm equation with respect to the electrical field distribution in the plane of the discontinuity. The second-kind Chebyshev polynomials are used as the basis and trial functions. Results of investigating the convergence of the developed algorithm are presented. It is shown that neglecting the plate thickness may result in a significant discrepancy between the expected and actual response functions of the bandpass filters constructed with the use of longitudinal strip diaphragms.
L. A.
Rud'
A. Usikov Institute of Radio Physics and Electronics, National Academy of Sciences of Ukraine 12, Academician Proskura St., Kharkov 61085
112-118
Effective Impedance of a Statistically Rough Surface: Numerical Analysis
The effective impedance of a statistically rough surface is analysed numerically within four theoretical models, over a range of magnitudes of the basic physical parameters. Comparison of the calculated results, as well as analysis of the effect of individual physical parameters on the impedance are carried out.
V. F.
Naumenko
Leonid Aleksandrovich
Pazynin
Institute of Radio Physics and Electronics of the National Academy of Sciences of Ukraine, 12, Academician Proskura St., Kharkov 61085, Ukraine
A. S.
Bryukhovetsky
A. Usikov Institute of Radio Physics and Electronics, National Academy of Sciences of Ukraine
119-132
Interaction of Surface Waves in Superlattice and Beam of Charged Particles
The theory of surface electromagnetic waves at the boundary of a layer-periodical structure and vacuum is developed. The excitation of these waves by charged particle, moving in vacuum along the normal to the interface and specularly reflected by the boundary, is investigated. The radiation field in vacuum is obtained. It is shown, that this field consists of the fields of the electromagnetic waves of a different physical nature: the surface cylindrical wave and the volume spherical wave. The power of the obtained radiation is of the same order as the power of the transition radiation, when the charged particles cross the interface.
S. I.
Khankina
A. Usikov Institute of Radio Physics and Electronics, National Academy of Sciences of Ukraine 12, Academician Proskura St., Kharkov 61085
V. L.
Falko
Vladimir M.
Yakovenko
A. Usikov Institute of Radio Physics and Electronics, National Academy of Sciences of Ukraine 12, Academician Proskura St., Kharkov 61085
133-139
Influence of Depletion Transition Layers on Surface Polaritons in Semiconductor Films
A theory of TM type surface polaritons in semiconductor films possessing depletion transition layer which electron concentration changes according to the law of hyperbolic cosine is built. The influence of dissipative as well as non-dissipative damping caused by plasma resonance in transition layer on dispersion properties of normal and tangential modes of surface polaritons is determined. It is shown that in the absence of dissipative damping two dispersion branches both for normal and tangential modes of surface polaritons exist, parted by a frequency gap. The account of dissipative damping leads to vanishing of the gap and the presence of a single dispersion branch both for normal and tangential modes of surface polaritons, wherein the damping of tangential mode exceeds considerably the damping of normal mode.
N. N.
Beletskii
A. Usikov Institute of Radio Physics and Electronics, National Academy of Sciences of Ukraine 12, Academician Proskura St., Kharkov 61085
E. A.
Gasan
140-148
Electromagnetic Step Signal Propagation in Lossy Waveguide
Propagation of the transient electromagnetic field in a waveguide with the perfectly conducting surface of arbitrary cross-section which is filled with a lossy medium is considered. Time Domain Method of Waveguide Evolutionary Equations has been used, and original initial-boundary value vector problem for Maxwell's equations has been reduced to integration of the one-dimensional Klein-Gordon scalar equation. Its solution is obtained as an expansion in terms of a suitable for Time Domain Method basic set. The expansion coefficients are readily derived through the same decomposition of the input signal. Analytical forms of early- and late- time approximations for propagating electromagnetic signal are presented, and the validity conditions for the exact solution are discussed.
K. M.
Yemelyanov
V. Karazin National University of Kharkov, 4, Svoboda Sq., Kharkov, 61077
Oleg Aleksandrovich
Tretyakov
V. Karazin National University of Kharkov, 4, Svoboda Sq; Kharkov, 61077
S. B.
Nikitskiy
149-159
Resonant Absorption of Electromagnetic Radiation in Matrix Disperse Systems with Metallic Inclusions
The absorption of electromagnetic radiation in low density system of fine metallic particles embedded in dielectric matrix is considered with account of influence of dipole-dipole interaction between particles. It is shown that under account of pair interaction between particles near proper plasma surface mode of a single particle two new neighboring resonant modes appear, their excitation creating the region of continuous spectrum. In a result, the mechanism of collisionless damping occurs leading to widening and doubling of the resonance peaks in absorption. The dependence of absorption on the average distance between particles and on collision frequency is examined.
L. G.
Grechko
Institute of Surface Chemistry, NAS of Ukraine, Pr. Nauki 31, Kyiv
A. Ya.
Blank
O. A.
Panchenko
A. A.
Pinchuk
160-169
The Riemann-Hilbert Method in the Electrodynamics of Unclosed Screens with Tapered Slots
The paper suggests a rigorous theoretical analysis of the distribution of electromagnetic field components in tapered wave guiding elements of antenna systems and slot and strip lines. By generalizing the well-known Riemann-Hilbert method an inverse operator of the static boundary-value problem has been obtained for the Laplace equation in the simplest geometry of a screen with tapered slots, namely, two equal conical cuts disposed symmetrically within a conductive plane. The summation of poorly convergent series for the unknown functions are presented. The results have been brought to analytical formulas for the field components and potential distribution through the whole space, including the cuts themselves.
V. N.
Koshparyonok
A. Usikov Institute of Radio Physics and Electronics, National Academy of Sciences of Ukraine 12, Academician Proskura St., Kharkov 61085
170-174
MATRIX OPERATORS IN DIFFRACTION PROBLEMS THE GENERALIZED MATRIX OF REACTANCES METHOD
As a further development of the of matrix operators method [1,2]and the concept of semi-inversion [3], a regularization technique of the solutions of diffraction theory problems is suggested permitting truncation of the infinite matrices in the numerical algorithms. In this way the treatment of resonant phenomena and inter-modal oscillations [4] in multi-mode structures is simplified so as to allow computerless analysis. The singularities impeding the inversion of the principal singular part of initial operators in the problems involving approaching slotted diaphragms are also avoided.
V. V.
Shcherbak
A. Usikov Institute of Radio Physics and Electronics, National Academy of Sciences of Ukraine 12, Academician Proskura St., Kharkov 61085
175-182
APPLIED RADIOPHYSICSA Hollow Dielectric Waveguide as a Field Former in Quasioptical- Waveguide Modeling of Electromagnetic Scattering
In the present paper, a hollow dielectric waveguide (HDW) is theoretically considered as a field former to be employed in the laboratory investigations of the scattering characteristics of physical objects or their scaled models by the method of quasioptical-waveguide modeling (QWM) in the near-millimetric /submillimetric wave range. The field quality criteria developed for the HDW-enclosed operation volume yield the easy and sufficiently accurate for practical purposes analytical relations which allow the designer to select optimum HDW parameters controlling the desired field characteristics within the operation volume. Applying the minimization criterion to longitudinal variations of the field in the operation volume reveals that a quasioptical forming structure of the HDW type admits a far greater extent of the operation volume as compared with free space. This opens the way to measure very extended scatterers through their scaled models which may be as long as hundreds and even thousands of the wavelengths.
V. K.
Kiseliov
A. Usikov Institute of Radio Physics and Electronics, National Academy of Sciences of Ukraine; V.N.Karazin Kharkiv National University 4, Svobody sq., 61022, Kharkiv, Ukraine
183-190
An Ultra-Broadband Quasioptial Polarization Attenuator for Metal-Dielectric Waveguides
A quasioptical polarization attenuator based on a metal-dielectric 14 mm square waveguide containing polarization gratings is considered. The inserted attenuation is from 0 to 25 dB over the frequency band from 78 to 400 GHz. Compared to the earlier waveguide and quasioptical polarization attenuators, this one is fitted with a more even reading scale.
V. I.
Bezborodov
A. Usikov Institute of Radio Physics and Electronics, National Academy of Sciences of Ukraine
M. S.
Yanovsky
A. Usikov Institute of Radio Physics and Electronics, National Academy of Sciences of Ukraine, Ukraine
V. K.
Kiseliov
A. Usikov Institute of Radio Physics and Electronics, National Academy of Sciences of Ukraine; V.N.Karazin Kharkiv National University 4, Svobody sq., 61022, Kharkiv, Ukraine
B. N.
Knyaz'kov
Ye. M.
Kuleshov
A. Usikov Institute of Radio Physics and Electronics, National Academy of Sciences of Ukraine, Ukraine
191-194
Radiation Resistance of an Electric Dipole Oriented Arbitrarily above a Plane Screen
A highly efficient algorithm and software package have been developed to calculate the radiation resistance of a dipole oriented arbitrarily above a plane screen, with account of secondary diffraction effects. The algorithm is based on an asymptotic solution obtained in the uniform geometrical diffraction theory technique for the 3-D diffraction problem of electromagnetic radiation from an arbitrarily oriented dipole by an infinitesimally thin metallic screen of rectangular form. A detailed numerical analysis has been performed to investigate the dependences of the radiation resistance of dipoles of various orientations as functions of their separation from the screen and the screen size, as well as of the side lengths ratio of the screen, with one of the lengths fixed/ It has been proved that the radiation resistance of a dipole located at a given height above the screen can be maximized by selecting an optimum dipole orientation, screen size and the side lengths ratio.
195-201