Yu. K. Sirenko
A. Usikov Institute of Radio Physics and Electronics, National Academy of Sciences of Ukraine
12, Academician Proskura St., Kharkov 61085, Ukraine
Exact 'Absorbing' Conditions in Outer Initial Boundary-Value
Problems of the Electrodynamics of Nonsinusoidal waves.
Part 3: Compact Inhomogeneities in Free Space
The exact 'absorbing' conditions are constructed, which make it possible to replace the 'open' initial boundary-value problems
in the radiation and scattering theory of nonsinusoidal electromagnetic waves by the 'closed' problems.
The coordinate artificial boundaries, on which these conditions are formulated, enclose the region where
all the efficient sources and scatterers are located. In this way the computational domain of the direct numerical
methods used for the analysis of transients in compact inhomogeneities of free space is found properly truncated.
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Ya.S. Shifrin, A.I. Luchaninov, and A.S. Posokhov
Kharkov National University of Radio Engineering and Electronics,
14, Lenin Ave, Kharkov, 61166, Ukraine
Structural Model of Antennas with Nonlinear Elements
A structural model of antennas with nonlinear elements, which is based on the analytical solution
to equations of state using the Volterra matrix series, is proposed. The properties of this model
and relations for calculating the external parameters of receiving antennas with nonlinear elements are considered.
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G.A. Alexeev and M.V. Belobrova
A. Usikov Institute of Radio Physics and Electronics, National Academy of Sciences of Ukraine
12, Academician Proskura St., Kharkov 61085, Ukraine
Convolution-Type Equation of Inverse Refraction Problem
The inverse refraction problem within framework in the geometric optical approximation made impossible
the reconstruction of the refraction index profile of the Earth's atmosphere on the surface measurements
of the wave refraction angle of the radiosource, which is on the moving satellite. In the work the analysis
of the probabilities of the numerical solution of the inverse refraction problem, which is reduced to an integral
Fredholm equation of the first-kind of convolution type has been made. It is shown, that the methodical error
of the equation solution by an integral Fourier transform method, which is predetermined by a hipping of the
time dependence of the refraction angle outside of the measurement interval by the different ways (in particular, zero values),
in the real situations exceeds the errors caused by the regularization and approximated measurements of the refraction angle.
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V.G. Sugak
Usikov Institute of Radio Physics and Electronics National Academy of Sciences of Ukraine
12. Academician Proscura St.. Kharkov 61085. Ukraine
Reconstruction of Electrical
Constants of Soil and Depth of Subsurface Objects Using Data of Subsurface Sounding
The problem of reconstructing the electric constants of a soil layer and the depth of its lower underlying boundary has
been formulated and solved. Its solution is found by means of the nonlinear singular equation for conductivity in terms
of the functional frequency dependence of the wave attenuation factor in the soil layer. This dependence is calculated
directly from the dada of subsurface probing.
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A.I. Omelchenko and A.F. Katasonov
Kharkov Military University, Kharkov, Ukraine
Procedure of Taking into Account the Effect of the Underlying Surface on the Measured Scattering Polarization Matrix of the Object
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V.V. Zhirnov, O.G.Lebedev, and L.Z. Sakhnovskaya
Kharkov National University of Radio Engineering and Electronics,
14, Lenin Ave, Kharkov, 61166, Ukraine
Radar Clutters from Inhomogeneities of the Ground Level Environment. Experimental Performances and Statistical Model
On the basis of theoretical end experimental studies, features of the ground and precipitation clutters
are considered. Such clutters cause sharp decrease of power contrast and the Doppler contrast
of the target signal from low-flying aircraft targets. It is shown that both complexity and high spatial-time l
iveliness of the amplitude distribution of the spectrum of such kind of clutters prohibit yielding a static model
by simple means.
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A.P. Kondratenko and S.V. Shapovalov
Kharkov Military University
Detection Coverage of Air Target in Bistatic Radar System with Television Illumination
Analysis is presented for possibilities of the bistatic radar systems with television illumination for the aerodynamic
target location over a whole altitude range of its flight. The analysis of influence of the transmitter antenna
pattern on an area detection is discussed.
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V.A. Abdulkadyrov, E.M. Khutoryan, and A.I. Tsvyk
A. Usikov Institute of Radio Physics and Electronics, National Academy of Sciences of Ukraine
12, Academician Proskura St., Kharkov 61085, Ukraine
Microwave Amplification Based on the Smith-Purcell Effect in a Distributed Semiconductor Structure
In terms of the small signal theory, we study the microwave amplification based on the Smith-Purcell effect
in a distributed semiconductor structure. The plasma in the semiconductor is considered in the quasi-hydrodynamic approximation.
A characteristic equation is derived and solved numerically.
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Yu.V. Arkusha, E.D. Prokhorov, I.P. Storozhenko
V. Karazin National University of Kharkov,
4, Svoboda Sq., Kharkov, 61077, Ukraine
Operation of Gunn Diode Containing Two
InP0.7As0.3-In0.4Ga0.6As Active Regions
The operation of Gunn diode with series concatenated InP0.7As0.3
and In0.4Ga0.6As active regions was analyzed in terms
of the two-temperature intervalley electron transfer model. The energy and frequency characteristics
of the diodes differing in the type of cathode metallic contact were obtained (barrier height is 0.04 eV).
The output characteristics of the diode with two active regions and a blocking metallic cathode were found
to result from the complex interplay between the physical processes occurring simultaneously in the two regions.
The highest output power flux was estimated to be ~40 kW/cm2 at a frequency of 42 GHz
and a generation efficiency ~20%. The diode with an antiblocking metallic cathode contact operates
as a heterocathode diode, i.e. a generation of current oscillations is provided exclusively
by the In0.4Ga0.6As active region.
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I.P. Storozhenko
V. Karazin National University of Kharkov,
4, Svoboda Sq., Kharkov, 61077, Ukraine
Modelling the Gunn Diodes Based on Variband Semiconductors
A two-temperature model of intervalley electron transfer in the variband semiconductor is developed.
This model was applied to examine the operation of the Gunn diodes based on the variband
Inx(z) Ga1-x(z) As. In the active diode region the semiconductor composition x(z)
is linearly coordinate-dependent. It is shown that operation of the diode with a variband active region is determined
by the coordinate dependency of relaxation frequency of electron concentration in the Ã-valley of
Inx(z) Ga1-x(z) As. If this frequency is a decreasing function of coordinate
(in the Inx(z) Ga1-x(z) As this occurs when x(z) increases) the dipole
domains propagate in the diode, while the opposite case is featured by the propagation of charged layers.
The maximum output power flux ~6.5 kW/cm2 was obtained for the GaAs-In0.4Ga0.6As -
diode at a frequency of 37 GHz with a 12% efficiency.
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O.I. Belous, A.I. Fisun, and O.N. Sukhoruchko
A. Usikov Institute of Radio Physics and Electronics, National Academy of Sciences of Ukraine
12, Academician Proskura St., Kharkov 61085, Ukraine
Synthesis of Basic Components of a Low-Noise Input Circuit for Millimeter Wavelengths
Input solid-state circuit consisting the parametric amplifier at the opposite-directed waveguides
and quasi-optical pumping generator is described.
Module proposed and investigated is meant for millimeter wavelengths.
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V.M. Zinkivsky and O.M. Nikitenko
Kharkov National University of Radio Engineering and Electronics,
14, Lenin Ave, Kharkov, 61166, Ukraine
Vacuum State Investigation of Cross-Field Devices by Discharge Current Techniques
The discharge current method was used to measure pressure into two electrode cross-field devices.
The theoretical and experimental performances were shown to measure vacuum state into such devices.
The boundaries were defined to use this method to measure pressure.
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O.G. Varfolomeeva, N.V. Katasova and A.A.Sinyavin
Kiev Institute of Communications
Minimization of the
Quadratic Integral Estimate of the Transient Process Quality in the Dual-Connected Automatic Phase Control System
A technique is suggested for determining parameters of the adjusting coupler between
the basic and complementary automatic phase control systems, based on the minimum condition
for the quadratic integral estimate. An example of the synthesis is presented.
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D.V. Ohruchak
Kiev Communication Institute
Iterative Phase Look Systems Having a Scaling Adjusting Loop
The problem of an accuracy increase of two-circuit iterative system with phase autotuning
by including of a scaling adjusting loop in the main control circuit is considered.
Parameters of scaling adjusting device are chosen on the condition of increasing in the order of astaticism.
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I. V. Barishev and M. L. Uss
National Aerospace University (Kharkov Aviation Institute),
17, Chkalov St., Kharkov, 61070, Ukraine
Application of Fractal Compression Methods for Image Filtering
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V.A. Chasovsky and M.P. Chernoborodov
Digital System of Asynchronous Pulse Noise Cancellation
An algorithm is considered for the processing of the radar information coming to the input of a coherent pulse radar.
The algorithm allows to detect and to cancel an asynchronous pulse noise (APN) by the processing of one range-bin.
The algorithm is based on the use of the Doppler phase filters formed on the basis of the coefficients
of the discrete Fourier transform. The results are presented of the mathematical simulation of the input signal
processing of a digital system for the APN cancellation, the system being based on the spectral analysis
of the APN characteristics. Several variants of the cancellation system are proposed.
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