2002, volume 7, № 3

ABOUT SOME PECULIARITIES OF APPLICATION OF THE FACTORIZATION METHOD TO DIFFRACTION PROBLEMS FOR PLANE TWO-DIMENSIONAL METAL-DIELECTRIC STRUCTURE

A. D. Barkov

437-445

The singularities of the functions due to application of the factorization method to the problem of the plane electromagnetic wave diffraction on a homogeneous dielectric layer with a perfectly conducting half-plane are studied in the paper. The dependence of the amplitude of the principal mode on the problem’s parameters are investigated.

RADIATION CHARACTERISTICS OF ELECTRIC DIPOLE WITH DIFFERENT ORIENTATIONS WHEN CHANGINGTHE POSITION OF A PLANE SCREEN

Gorobets N. N., Yeliseyeva N. P.

446-456

An electromagnetic field has been determined on the basis of the uniform geometrical diffraction theory throughout the observation space of a radiating system in the form of an electric arbitrary oriented dipole and perfectly conducting infinitely thin rectangular screen at arbitrary screen position relative to the emitter. On the basis of the elaborated algorithm, the directed and power characteristics of the radiating system have been calculated and studied under changes of screen position. Directions of the radiation maximum, maximum values of the directed action coefficients and resistances of dipole radiation have been determined depending on the screen position.

ESTIMATION OF THE NEAR-FIELD OF A CURVED DIPOLE IRRADIATOR IN A DISSIPATIVE MEDIUM

Alexeev G. A., Belobrova M. V.

457-461

A comparative analysis of the near-field of the curved and straight-line symmetrical half-wave dipole irradiators in a dissipative dielectric medium such as fat or muscle tissues on the frequencies 50 and 100 MGz for RF hyperthermia conditions is performed. The distributions of currents and fields are calculated as a function of irradiator curvature radius. It is shown that the irradiator curve increases the dissipative energy in the hyperthermia camera center by about 30%.

E- AND H-POLARIZED PLANE WAVE SCATTERING AND ABSORPTION BY AN IMPEDANCE STRIP GRATING

Zinenko T. L.

462-467

The problem of the plane wave scattering by an impedance flat strip grating with one-dimensional periodicity located in free space is considered. The problem formulation involves a set of the generalized boundary conditions relating the fields to the effective electric and magnetic currents. We have developed an accurate numerical solution to this problem by the method of the dual series equations and analytical regularization that guarantees a fast convergence and controlled accuracy. The computations have been carried out for the reflected, transmitted, and absorbed power fractions as a function of the normalized frequency for various impedance value.

WAVE SCATTERING BY A RECTANGULAR DIELECTRIC CYLINDER

Illyashenko L. N.

468-473

The problem of electromagnetic wave scattering by a rectangular dielectric cylinder is considered. To obtain a set of the first-kind Fredholm singular integral equations, single-layer potentials are used. On extracting and analytically inverting asingular part of the integral operator these equations are reduced to the Fredholm second-kind infinite matrix equation, which is solved numerically with an arbitrary pre-established accuracy. A Galerkin method of moments with angular exponents as global basis functions is applied. Sample numerical results are presented for cylinders of arbitrary size of rectangular cross-sections and for different angles of incidence of the H- and E-polarized plane waves.

POWER SPECTRA OF THE RADAR BACKSCATTERING BY THE SEA FOR SMALL GRAZING ANGLES

Gutnik V. G., Kulemin G. P., Sharapov L. I., Gorbach N. V.

474-483

The power spectra of the sea backscattered signals at the frequency band from1 to 150 GHz are analyzed, the dependences of the spectrum parameters on the radar operation frequency, the wind velocity, and the sea wave height are discussed. The experimental spectra of frequency of 140 GHz are obtained. It is shown that at the millimeter band of radiowaves the power spectra are bimodal under the condition of sea wave breaking, the relation between the second mode parameters and heavy sea roughness is considered. The conclusions are made about the 2-nd mode shaping by backscattering on a spray (drop) fraction formed at wave breaking.

ІTATISTICS OF RADIO SIGNAL FLUCTUATION OF A SHORT-WAVE PART OF THE MILLIMETRE RADIOWAVE BAND IN THEIR DISTRIBUTION ABOVE SEA SURFACE

Gutnic V. G., Gorbach N. V., Gorobets V. N., Sharapov L. I.

484-490

The of results investigation of radio signal amplitude fluctuation and entry corners of a short-wave part of the millimetre radiowave band in their distribution above the sea surface are reported. The features of statistical characteristics of these fluctuations are   reported. The model explaining these features is offered. It is shown that these features are related to appearance of a limited number of mirror reflecting sections on the sea surface.

RECONSTRUCTION OF ELECTRICAL CONSTANTS OF SOIL AND DEPTH OF POSITION OF OBJECT’S BOUNDARY BY THE OUTCOMES OF SUBSURFACE PROBING

Sugak V. G.

491-497

The problem of reconstruction of electrical constants of a soil layer and the depth of its lower boundary has been set out and solved. The result is obtained directly from the data of subsurface probing on the basis of the solution of the nonlinear singular integral equation for unknown conductivity with the measured dependence of attenuation factor on frequency.

DETECTION OF SPLITTING OF SHUMANN RESONANCE EIGEN-FREQUENCIES

Nickolaenko A. P., Rabinowicz L. M., Shvets A. V., .Schekotov A. Yu.

498-508

We present the experimental results and theoretical interpretation, which prove that elliptical polarization of the horizontal magnetic field at the extremely low frequencies is indicative of on the lift of еру degeneracy of the resonance oscillations under the influence of the geomagnetic field. The sense of polarization remains unchanged in the vicinity of the resonance peaks, owing to the west-east traveling waves dominating in the radio propagation.

EVALUATION OF THE ATMOSPHERIC AEROSOL PARTICLE SIZE IN THE REFLECTIVE LAYER PRODUCED BY STRONG SOLAR FLARES

Goncharenko Yu. V., Kivva F. V.

509-512

The hypothesis for the influence of aerosol layers produced by strong solar flares on variations of low and middle atmosphere temperature profile is considered. Estimated aerosol particle size does not conflict with water aerosol physics and approximately corresponds the maximum of H-distribution for stratospheric aerosols.

INTERACTION OF ELECTROMAGNETIC PLANE WAVE WITH A SEMICONDUCTOR –DIELECTRIC STRUCTURE WITH А DIFFRACTION GRATING

Abdulkаdyrov V. A., Khutoryan E. M., Tsvyk A. I.

513-517

Interaction of electromagnetic plane wave with a semiconductor-dielectric structure with а diffraction grating has been investigated. The reflection and transmission coefficients have been obtained. Numerous experiment results are given.

AN OPTIMIZED ANTENNA FOR PLASMA PRODUCTION IN THE PR-1 DEVICE

Grekov D. L., Azarenkov N. A., Bizyukov A. A., Olefir V. P.

518-521

The PR-1 device is a wide-aperture source of homogeneous plasma. It is used for processing of large diameter plasma samples. The plasma production by high frequency (HF) fields with the use of a circular antenna was carried out earlier. These calculations have shown that the radial antenna currents provide more efficient HF power as compared to azimuth antenna currents. The paper deals with calculations of a new antenna for plasma production in the PR-1 device. As compared to the previously used one, this antenna has developed surface currents in a radial direction. Their electromagnetic field pattern in the device vessel is investigated too.

A FREQUENCY MULTIPLIER-CONVERTER BASED ON A RETARDED FIELD DIODE

Zorenko A. V., Bludov A. V., Kritskaya T. V.,Chaika V. E.

522-526

The dependences of the output power and conversion ratio for a multiplier-converter based on a controllable avalanche breakdown upon adjustment of the external circuit and operating conditions are given. The possibility is shown to multiply the frequency by 20 times with 18-dB loss of the output frequency in the short-wave part of the millimeter wavelength range.

PECULIARITIES OF A JOINT OPERATION OF RESONANCE TUNNELLING AND GUNN DIODE

Botsula О. V., Prokhorov E. D.

527-531

The operation of a series - connected resonant tunnelling diode and Gunn diode in the resonance circuit is considered. The current - voltage (I-V) characteristics of such combination of diodes have the peculiarities which lead to a current jump at the voltage increase or decrease. The peculiarities of the I-V characteristic and current jump at determined current waveform in the resonance circuit are analysed for the different diode’s lengths. The mm - wave oscillation can occur through the resonance tunnelling or intervalley of electron transfer under certain diode parameter conditions. When diodes are connected in series, there are two oscillation regions through the resonance tunnelling and intervalley electron transfer. The oscillations in this region are possible at multiple frequencies.

BROADENING OF DYE LASER TUNING RANGE BY MATCHING PARAMETERS OF ACTIVE ELEMENT AND CAVITY

Nikolaev S. V., Pozhar V. V.

532-538

The theoretical and experimental investigations have been made of the dependences of the tuning band and generation energy of the rhodamine 6G dye laser on the concentration of dye, active medium length and spectral characteristics of the reflection coefficient of the resonator output mirror. The dependences of the range width of laser tuning on the cell length and mirror spectral characteristic are found and explained. Based on these investigations, a method of the range expansion of the dye laser tuning by using the resonator output mirror with a non-linear spectral characteristic is proposed.

ON THE PHASE ELECTRON SELECTION BY LONGITUDINAL-TRANSVERSAL FIELD COMPONENT

Alexeev G. A.

539-542

The analysis of the phase electron selection in a transversal cross-section of the interaction channel of the resonance O-type oscillator by the transversal (to the drift direction of the electron beam) space field component being in the plane of the periodical structure, is performed. It is shown that the phase electron selection by the longitudinal-transversal component is more effective than the selection by the component being orthogonal to the plane of the periodical structure. But at the small deviation of the focused finite magnetic field direction from the propagation direction of the space field harmonic which causes the longitudinal- transversal component, the influence of the phase selection on the interaction power is weak and no explained the essential (on 25-35%) increasing of the oscillator power.

THE INFLUENCE OF DESIGN PARAMETERS ON ELECTROSTATIC POTENTIAL DISTRIBUTION BETWEEN ELECTRODES WITH COMPLEX CONFIGURATION

Volovenko M. V., Nikitenko O. M.

543-547

An adapted expression for electrostatic potential distribution between electrodes with complex configuration is used. Comparative dependences of the coefficients from the expression for electrostatic potential distribution on the system geometric parameters are shown. The limits of using such approach in description for the electrostatic potential distribution in the systems with a complex configuration of electrodes have been determined.

ESTIMATION OF THE INFLUENCE OF HARDWARE INACCURACY ON THE FEATURES OF A RADAR FOR NEAR TARGET LOCATION

Sytnique O. V., Myroshnychenko Y. I., Kopylov U. A.

548-554

The paper considers the problems of functioning of the near target location radar systems. Heavy jummer situation, in which such systems happen to work, dictates the requirement for the radiated signal. The presence of multiplicative jummers complicates the creation of the optimum radar echo-signal processing algorithms. The use of signals with a big base and a complex type of modulation requires making the hardware, providing high accuracy of signal shaping and processing. The investigation of errors, put into the signal at the stage of its shaping, and their influence upon the resulting features of the system has shown as a whole the possibi-lity of a compromise variant of the equipment design. The classification of errors is given. An efficient mathematical system is offered for creation of the surfaces of the possible errors.

OPTIMIZATION OF THE RADIATING SYSTEM DIELECTRIC WAVEGUIDE – GRATING FOR AN AUTOMOBILE RADAR SCANNING ANTENNA

Yevdokimov A. P., Kryzhanovsky V. V.

555-560

A radiating structure consisting of a linear dielectric waveguide and a diffraction grating is treated. This structure serves as a basis for a scanning antenna designed for automobile radar. The conditions of the radiation pattern forming in vertical plane are investigated, the axis of dielectric waveguide being horizontal. Analysis of diffraction grating width influence on shape and width of radiation pattern is done. Optimal angles of cylindrical lens or parabolic reflector irradiation are determined when focusing in the vertical plane is needed. Radiation pattern of two parallel diffraction gratings is investigated, having in the general case different values of periods. The criterion of a continuous mode of scanning is determined in the system, including comparatively narrow diffraction gratings mounted on the lateral surface of a rotating metal cylinder. Practical recommendations on scanning antennas design are formulated with continuous and step modes of scanning.

AN AUXILIARY UHF GENERATOR INCORPORATED INTO A POWERFUL PULSED AUTOGENERATOR

Beloglazov V. I., Dovbnya А. N., Mos’pan P. I.

561-564

On the basis of the given analysis, a need of introducing an auxiliary, relatively nonpowerful generator incorporated into a powerful klystron autogenerator is motivated. Its output UHF power, brought to the input of a klystron autogenerator, reduces the trasition time of fluctuations to some shares of a microsecond. The requirements are worded to the level of output power of an auxiliary generator and the frequency of fluctuations generated by it are formulated. The conclusion is made on the need of using a pulsed regime for the auxiliary generator. The schemes of auxiliary generators giving to load 100-150 Watt of radio-frequency power are shown. Several such generators are used in NSC KFTI electron accelerators.