V.I. Lutsenko, S.I. Khomenko, A.Ye. Zatserklyany, and I.V. Lutsenko
A. Usikov Institute of Radio Physics and Electronics,
National Academy of Sciences of Ukraine
12, Academician Proskura St., Kharkov 61085, Ukraine
Simulation Statistical Model of Reflection from the "Clear-Sky"
In terms of the results from using the half-Markov process theory a simulation statistical model of the "clear-sky" reflection has been developed. The experimental data have provided the basis for estimating the model parameters. The results thus obtained enable one to simulate the "clear-sky"-scattered signal.
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N.V. Gorbach, L.I. Sharapov, and V.G. Gutnik
Institute of Radio Astronomy, National Academy of Sciences of Ukraine
4, Krasnoznamennaya St., Kharkov 61002, Ukraine
Specific Statistical Characteristics of Three Millimeter Waves Propagating over Rough Sea
The paper presents some experimental data on three-millimeter radio signal fluctuations while propagating over sea surface. The amplitude fluctuations and arrival angles of the direct and reflected signals have been statistically analyzed. The matching between the experimentally obtained amplitude fading probabilities and theoretical laws has been examined. The dependences between certain surface characteristics and signal fluctuation nature have been investigated. The correlations between signals in the amplitude and the corner channels of the direction finder for point targetd have been explored. Experimental results on the amplitude and angular fluctuation spectra at sea and on land have been analyzed. A record of the average and fluctuation errors of the finders is presented.
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D. Djebouri, A. Djebbari, and M. Djebbouri
National Centre of Space Techniques, Space Instrumentation Division.
Djillali Liabes University, BP. 89, Sidi Bel Abb?s, 22000, ALGERIA.
A New Robust GPS Satellite Signal Acquisition Using Lifting Wavelet
A design for robust and less complex GPS satellite signal acquisition system using fast lifting wavelet decomposition is proposed. Acquisition in GPS system is used to calculate the code phase (or shift) and find the pseudo-range, which is used to calculate the position. The level of GPS receiving equipment system noise determines in part how precisely pseudo-range can be measured.
A substitute algorithm for calculating the convolution by using fast lifting wavelet decomposition is proposed in order to carry out a robust less complex GPS signals acquisition system and to facilitate its implementation with maximum of accuracy in the presence of noise.
Simulation is used for verifying the performance which shows that the proposed scheme based fast lifting wavelet transform outperforms the FFT search scheme in the presence of an hostile environment.
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N.N. Beletskii and Y.V. Bludov
A. Usikov Institute of Radio Physics and Electronics,
National Academy of Sciences of Ukraine
12, Academician Proskura St., Kharkov 61085, Ukraine
Edge Magnetoplasmons in a Finite Array of Two-Dimensional Electron Gas Strips
The paper deals with the theoretical investigation of edge magnetoplasmons in an array of two-dimensional gas strips, consisting of a finite number of strips, arranged at an equal distance from each other and placed into an external magnetic field. Two types of arrays of two-dimensional gas strips are under consideration: an ordered array of two-dimensional gas strips with equal electron concentrations in all strips and a weakly disordered array of two-dimensional gas strips, which is characterized by the fact that the electron concentration of one defect strip differs from that of other strips. It is shown, that the edge magnetoplasmon spectrum contains an infinite number of modes, which differ from each other by the distribution of the electromagnetic field applied across the strips. The anomalous dispersion of the edge magnetoplasmons of higher modes in a long-wavelength region is predicted. The existence of edge magnetoplasmon local modes of each kind, properties of which differ from properties of other modes of edge magnetoplasmons, is shown for the case of the weakly disordered array of two-dimensional electron gas strips. In the case where the defect strip is arranged inside the array of strips, the existence of edge magnetoplasmon modes, the frequencies of which do not depend upon the parameters of the defect strip, is predicted.
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Yu.O. Averkov
A. Usikov Institute of Radio Physics and Electronics,
National Academy of Sciences of Ukraine
12, Academician Proskura St., Kharkov 61085, Ukraine
Transition Radiation by an Electron Bunch That Crosses the Vacuum/Left-Handed Material Interface
ransition radiation by a non-relativistic electron bunch that crosses an interface of a vacuum/left-handed material has been theoretically investigated. The electron density of the bunch is described by the Gauss distribution. It is shown that as a result of the transition radiation both bulk and surface electromagnetic waves can be excited in the frequency region where the refractive index of the left-handed medium is negative. At the same time the dispersion of the surface electromagnetic waves can be negative as well as positive, depending on the relation between the plasma frequency and the resonance frequency of a left-handed material. The energy flows of the surface and bulk electromagnetic waves have been calculated.
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Î.I. Belous, A.I. Fisun, and Î.N. Sukhoruchko
A. Usikov Institute of Radio Physics and Electronics,
National Academy of Sciences of Ukraine
12, Academician Proskura St., Kharkov 61085, Ukraine
M-Band Low-Noise Semiconductor Amplifier
Problems of decrease of loss in a parametric two-circuit amplifier trough the use of dielectric inserts with the inclined edges as a resonant circuit of no-load frequency are considered in the study. Results of electrodynamic simulation of oscillatory processes in a dielectric insert in a rectangular waveguide are represented. Experimental amplitude and noise characteristics of the breadboard model of the parametric amplifier realized on the basis of the considered filter are given. Within the range of 60 GHz the amplification factor has been obtained no less than 12 dB over a half-power bandwidth of 1.2 GHz with a noise temperature of 550 K.
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D.M. Vavriv and S.V. Sosnytskiy
Institute of Radio Astronomy, National Academy of Sciences of Ukraine
4, Krasnoznamennaya St., Kharkov 61002, Ukraine
Non-Stationary Theory of Spatial Harmonic Magnetrons with Cold Cathode
Non-stationary theory of spatial harmonic magnetrons with cold cathode has been suggested. The principal idea at derivation of the magnetron mathematical model is use of equivalent circuit of a magnetron oscillating system in the form of a closed chain of connected nonlinear oscillators. The representation of the magnetron oscillating system in the form of the equivalent circuit describes all the TEn1-modes taking into account of formation of doublets as well as allows studying of non-stationary processes.
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V.M. Kuzmichev, S.V. Pogorelov, and P. Kohns
V. Karazin National University of Kharkov,
4, Svoboda Sq., Kharkov, 61077, Ukraine
Transformation of the Continuous Laser Power on the Wave Length 10.6 Microns by the Thin-Wire Platinum Bolometer
Using the temperature dependence of a specific resistance of platinum, relation of a complex index of refraction with a specific conductivity in the long-wave approach, temperature dependence of coefficient of heat exchange of the bolometer with an environment and the solution of a heat-balance equation averaged along the bolometer length, we derive a transformation coefficient of a thin-wire bolometer within a wide range of the continuous laser power at a wavelength of 10.6 microns.
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