S.I. Khomenko, A.Ye. Zatserklyany, and V.I. Lutsenko
A. Usikov Institute of Radio Physics and Electronics,
National Academy of Sciences of Ukraine
12, Academician Proskura St., Kharkov 61085, Ukraine
The Atmospheric Refraction Influence upon the "Clear-Sky" Reflections

The "clear-sky" backscattering characteristics have been experimentally studied. The results obtained by means of high-potential pulse C-, X-, Ka-, and UHF-band radars as well as with a high-potential cw C-band radar are presented. The statistical characteristics of the "clear-sky" returns have been explored and their dependence upon the tropospheric-refraction factor gradient has been found.

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Yu.V. Goncharenko, V.G. Gutnik, and F.V. Kivva
A. Usikov Institute of Radio Physics and Electronics,
National Academy of Sciences of Ukraine
12, Academician Proskura St., Kharkov 61085, Ukraine
Experimental Investigation of SHF Signal Fluctuation During Solar Proton Events

Results of the experiment related to reception of SHF signal from a geostationary satellite visible from the point of reception under the elevation angle of 4.5 are considered. It was shown that the particularity of the received signal lies in a significant increase of fluctuations during a powerful solar proton event. The influence of ionospheric and tropospheric effects related to solar flares upon the parameters of telecommunication channel was estimated on the basis of known models. It was demonstrated that acting independently the considered mechanisms of solar-terrestrial interdependences cannot provide for alterations of the signal intensity registered during the experiment.

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N.G. Don
A. Usikov Institute of Radio Physics and Electronics,
National Academy of Sciences of Ukraine
12, Academician Proskura Str., Kharkov 61085, Ukraine

Scattering Matrix Calculation of Plane Junction of Hollow Uniform Waveguide of Arbitrary Cross-Section

The plan for handling a problem on the plane transverse junction of hollow regular waveguides of arbitrary cross-section with perfectly conducting walls is presented. The contour integration is used to compute mutual-coupling coefficients between the waveguide modes. The method is tested by the example of the coaxial junction of two circular waveguides. The described method is a key element of solving the more general problem of the analysis of complicated waveguide devices.

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R.I. Bilous, I.O. Bilous and A.P. Motornenko
A. Usikov Institute of Radio Physics and Electronics,
National Academy of Sciences of Ukraine
12, Academician Proskura St., Kharkov 61085, Ukraine
Measuring Technique for Dielectric Parameters at the Microwave

In this paper measurement technique of the complex permittivity of the dielectric materials over a wide frequency band using the waveguide-dielectric resonator based on a circular evanescent waveguide has been presented. Permittivity and the loss tangent of a dielectric of the fluoroplast-4 have been measured for the H11p mode in the frequency band 9.5-13.5 HGz. A comparison between of the obtained parameters and data of the reference book and original papers has been made

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Yu.V. Kirichenko
National Research Center ,
Kharkiv Physical & Engineering Institute, Kharkiv, Ukraine
Nonlinear Dynamics of Electrons in the Orbitron Type Systems

The nonlinear analysis has been performed to determine the energy exchange between rotating non-relativistic electrons with the basic rotating wave in the coaxial cavity immersed in crossed radial-electrostatic and axial-magnetic fields. The method is proposed to increase the efficiency of the orbitron type system based on phase selection of electrons, with the help of which the "worked-out" electrons having unfavorable for generation phase are removed from the interaction space. The correlation for optimum electron, wave and cavity parameters allowing to perform the optimal phase selection mode is obtained. If the electrons are inserted from the end-face of cavity then the efficiency of such a system will be more than twice as large as the efficiency of the orbitron-type systems. It is demonstrated that inclusion of the axial magnetic field in addition to the radial electrostatic field allows to increase the efficiency by almost two times.

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V.A. Soshenko and O.V. Sytnik
A. Usikov Institute of Radio Physics and Electronics,
National Academy of Sciences of Ukraine
12, Academician Proskura Str., Kharkiv 61085, Ukraine Simulation of Electric Oscillations in the Helical Explosive Generators

The research of a class of helical radio-frequency explosive-driven magnetic-flux compression generators (MCG) the basic advantages of which are their small size, simple design, off-line operation and high power intensity, is carried out in the paper. The analysis of various designs of helical MCG is executed on the basis of the developed specified equivalent circuits and mathematical models of MCG. In particular, the MCG with a capacitor and two-loop loads as well as with the load of a non-linear connection two-loop system based on the ferrite core are investigated. The models are considering the factors, which exert influence upon the amplitudes of generated currents and voltages and upon the spectral characteristics of electromagnetic fields. Mathematical models are submitted as systems of differential equations with variable factors taking into account the skin-effect, losses of energy due to short circuit in the liner, resistive losses in helical and transitive contacts. The conditions, at which the failure of an oscillatory mode and transition of the generator into a-periodic mode occurs, are obtained. Calculations of time and spectral characteristics of signals are executed. Methods for increasing of the power and the frequency of generated oscillations are investigated. In particular, it is suggested to use nonlinear elements and elements with the distributed parameters in the MCG designs. Original circuit-related and structural solutions of MCG are discussed.

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N.F. Karushkin
Research institute "Orion"
8à, E.Potje Str., Kiev, 01057, Ukraine
Millimeter-Wave Band Modules

The design of millimeter-wave semiconductor modules is considered. These modules are transmitting pulse devices with application of impact avalanche transit-time diodes, high divisible frequency converters, and control devices based of pin-diodes. Power sources with application of ring distributed-type diodes are offered.

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