2005, volume 10, № 2

THE STRONG APPROACH FOR ANALYSIS OF TRANSIENTS IN THE AXIALLY-SYMMETRICAL WAVEGUIDE UNITS

Pazynin V. L., Sirenko K. Y.

183-192

The exact ‘absorbing’ conditions for virtual boundaries in the cross-sections of regular circular and coaxial circular waveguides are constructed, which allow one to truncate efficiently the computational domain of finite-difference methods as applied to the simulation of transients in open axially-symmetric waveguide resonators. The ‘open’ problems that describe impulsed - and -waves in the structures of this kind are reduced to the equivalent ‘closed’ ones. The so obtained conditions are embodied in the computer programs for the analysis and model synthesis of functional units of impulse wave radiators.

FREQUENCY-SENSITIVE PROPERTIES OF THE SCREEN WITH RECTANGULAR APPERTURES AND WAVEGUIDE LOADS

Gribovsky A. V., Prosvirnin S. L. 

193-198

The frequency characteristic of the two-periodical perfectly    conducting two-element finite thickness screen consisting of  segments of rectangular waveguides is studied numerically. One of waveguides is short-circuited and is waveguide load. The ability of the full reflection or transmission of electromagnetic energy of the same frequency is shown by applying the p-i-n diode into the short-circuited waveguide.

THE COMPUTATIONAL ALGORITHM CORDIC FOR ELECTROMAGNETIC SCATTERING PROBLEM

Mizrakhy S. V. 

199-202

The CORDIC algorithm capability for numerical solution of some electromagnetic scattering problem is considered. The algorithm allows strictly and fast computing a wide range of trigonometric functions as well as vector rotation for the given angle by shift-add operation. The computation results of Radar Cross Section (RCS) patterns for rectangular cylinder obtained by Geometric Theory of Diffraction using CORDIC are presented.

ON POSSIBILITY OF MONOPULSE PHASE-DIFFERENCE METHOD OF DIRECTION-FINDING USAGE FOR AIR TARGET LOCATION IN THE ACTIVE-PASSIVE SYSTEMS WITH NOISE-LIKE SIGNAL

Belov E. N., Zarichn’ak E. M., Lutsenko V. I., Lutsenko I. V., Yakovlev V. G. 

203-206

Possibility of air target location on basis of signal angle of arrival information, scattered from target, with the external source "illumination" is considered. Monopulse phase-difference direction-finder is developed and produced. Provisional data of over reflecting signal angle of arrival measurement during the airplane flight are obtained.

A STUDY OF SECTORIAL HORN-PARABOLIC ANTENNA FOR WIRELESS COMMUNICATION SYSTEMS

Teplyuk A. L., Khlopov G. I. 

207-211

The paper describes the application of scattering pin in aperture of horn-parabolic antenna for beamwidth expansion up to 200 deg. An influence of the scatterer dimensions and its location on the antenna power pattern is studied for E- and H-plane horns. It is shown that the application of cylindrical scatterer provides    essentially expansion of antenna beamwidth, which can be used in order to shape antenna patterns for broadband communication systems of “point-to-multipoint” type.

ELECTRON DENSITY SEASONAL VARIATIONS MODELING IN F2-REGION IONOSPHERE MAXIMUM FOR LOCAL MIDNIGHT AND NOON

Lyashenko M. V.

212-216

The experimental database over the 1986–2002 period obtained at Kharkov incoherent scatter radar had used for modeling seasonal variations of ionospheric F2-peak electron density N_m. The regression dependencies of the N_m from solar activity (SA) index were obtained. Coefficients of the regression for all seasons were calculated. Seasonal variations of N_m for 00 and 12 LT for all levels of SA had reconstructed. A comparison between calculated and experimental values was carried out. Good agreement between them under any solar activity level was noticed. The features of the seasonal variations of the N_m for the SA different phases are considered. Obtained results are used for improvement of empirical ionospheric Central Europe region model.

THE DOUBLE–FREQUENCY MEASURING CHANNEL FOR IONOSPHERE PARAMETERS DETЕRMINATION BY A METHOD OF INCOHERENT SCATTER

V. N. Lysenko, Y. V. Tcherniak

217-223

The method of incoherent scattering (IS) of radiowaves is considered as the most information technique for ionosphere parameters definition in a wide altitude (h) range: electronic concentration N_e(h), electronic T_e(h) and ionic T_i(h) temperatures, ion composition and others parameters. The method is realized by IS radars and based on remote sensing of ionosphere plasma and correlation (or spectral) processing of a sounding radio signal, that scattered on thermal fluctuations of electronic concentration. The double–frequency measuring channel, which consists of a transmitting two–channel device, antenna–feeder device, radiowaves propagation channel – ionosphere, receiving antenna, receiving device, correlator is considered. The integrated expression, which links parameters of a scattering medium, duration and form of a sounding radiopulse, a pulse response of the receiving channel is obtained. The developed technique of processing IS signal has allowed to obtain the reliable data about electronic concentration distribution in heights interval 100–1000 km in one measurement session. Results of modeling and measurements of time–altitude dependences N_e in undisturbed conditions for two seasons are submitted.

TWO COMPONENT MODEL OF SCHUMANN RESONANCE SIGNAL

Yatsevich E. I., Nickolaenko A. P., Shvets A. V., Rabinowicz L. M. 

224-232

It is shown in this work, that Schumann resonance signal is the sum of two components: a variable part and a constant background. The variable part is described by the model of one mobile source. It is connected with movement of the global thunderstorm activity around the Earth along the equator and depends on the time of a day. The background component remains a constant during a day, which depends on the season. Estimations are received for contributions from two components in the general intensity. It is shown, that intensity of the background is comparable to that of the variable part. The seasonal variations are received for variable and constant parts. It is shown, that both parts of a signal are characterized by similar monthly changes that  allows us to assume that these have similar origin.

AUTOMATED SYSTEM FOR UWB ANTENNAS CHARACTERISTICS MEASUREMENT

Petrechenko V. M., Pochanin O. G., Pochanin G. P., Ruban V. P. 

233-239

The paper is about development of the automated system for UWB antennas characteristics investigation. The set of equipment    including nonstandard, specially developed units and software as well as functional capabilities of the system are described.

USE OF THE GEORADAR FOR GROUNDWATER TABLE DETERMINATION AND MAPPINGS OF THE TERRITORIES POLLUTED WITH OIL

Sugak V. G., Bukin A. V., Ovchinkin O. A., Pedenko Yu. A., Silaev Yu. S. 

240-247

In the article it is brought the outcomes of theoretical and experimental research of opportunities of subsurface radar probing for decision of problems of engineering - geological researches - definitions of depth of a level of subsurface water, definitions of soil lithologic section structure of zones of aeration, and also depth of deposition and thickness of a layer of oil products formed as a result of various sort of man-caused outflow. It is shown, that use of step-by-step radar probing successfully solves the specified problems, providing a number of essential advantages in comparison to traditional methods of geophysical researches, and in comparison with use of radar subsurface probing with pulse signals.

TRANSITION RADIATION BY AN ELECTRON BUNCH THAT CROSSES AN INTERFACE OF A VACUUM-LEFT HANDED MATERIAL

Averkov Yu. O. 

248-255

Transition radiation by 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 Gauss distribution. Both bulk and surface electromagnetic waves can be excited in the frequency region where the refractive index is negative. At the same time the dispersion of the surface waves can be negative or positive. It depends on the relation between the plasma frequency and the resonance frequency of a left-handed material. The energy flows of both surface and bulk electromagnetic waves are calculated.

A BISTABILITY PHENOMENON IN THE RESONATOR WITH NON-LINEAR BOUNDARY SIMILAR TO THE SEMIMAGNETIC SEMICONDUCTOR

Bondarev O. A., Ivanchenko I. V., Karelin S. Yu., Popenko N. O. 

256-260

The computational modelling of characteristics of the three-mirror resonator with non-linear boundary similar to the semimagnetic semiconductor with spin-magnetoplasma wave excited on its surface has been carried out. Moreover, bistability conditions in the electromagnetic structure noted above have been determined. It has been shown that the structure likes that can be considered as a trigger or a limiter prototypes for applications in terahertz wavelength range systems. Here, the characteristics of those should be controlled by external magnetic field changing.

SURFACE MAGNETOPLASMA WAVES ON THE INTERFACE OF TWO SEMICONDUCTOR SUPERLATTICES

Olkhovskiy Y. A., Shramkova O. V. 

261-265

The magnetoplasma waves existent along the contact of two   periodic semiconductor superlattices, placed into external magnetic field, have been discovered in the work. It is assumed that the vector of magnetic field is situated in the plane of structure layers, and waves propagate in the perpendicular plane. It was shown, that three types of surface waves, differing by the phase properties, took place. The dispersion dependencies for the surface waves and distribution of field components are investigated. It was analyzed the distribution of energy flow in a surface wave on the layers of lattices.

EXPERIMENTAL RESEARCH OF SPHERICAL PLASMA CREATIONS

Bulgakov А. А., Yefimov B. P., Kuleshov А. N., Khorunzhiy М. О. 

266-269

Results of experimental research in discharge processes appearing in water medium are given in this paper. We describe our model and measuring method. Conditions of creation the spherical form plasmoid have been made in water-air system. The radiation with hard photons is experimentally obtained from discharge space. We propose the theoretical model of creation and existence of spherical plasma creations. We try to explain stability of spherical creations due to eigen (no homogeneous) electromagnetic waves, which are known from literature as “complex” waves appearing in plasma mediums.

EXPERIMENTAL INVESTIGATION OF INTERACTION BETWEEN ELECTRIC BEAMS AND SEMICONDUCTOR PLASMA

Zamuraev O. A., Lopatin I. V., Rusanov A. F.

270-275

The paper reports the results of realization the experiments on the interaction between non relativistic electron beams and semiconductor structures excited electromagnetic fluctuations of millimeter of a range of waves in an interval of temperatures from +30 up to -196°C. The features of a technique of researches and experimental assembly are considered. A SHF the signals received at frequency of excitation 70 GHz and nitric temperature semi-conductor (InSb) of samples, are interpreted as result of interaction of an electronic beam with surface waves in semiconductor plasma.

MAGNETORESISTANCE AND MAGNETOIMPEDANCE PROPERTIES OF NANOCOMPOSITES WITH SPIN-DEPENDENCE TUNNEL MAGNETORESISTANCE

Bagmut T., Nedukh S., Khodzitskiy M. 

276-280

The expansion of investigation of giant magnetoimpedance (GMI), tunnel magnetoresistive (TMR) effects for magnetic structures (CoFeZr)_ХSiO_1-Х - composite (x% = 34, 40, 43, 47), Co_Х(TiO₂)_1-Х in a millimeter waveband lengths area is the purpose of given paper. With the help of a method of an electronic paramagnetic resonance (EPR) the lines of a ferromagnetic resonance recorded at temperature 300 K in the band of frequencies 38-45 GHz. The dependencies of a resonant frequency on a magnetic field are retrieved and analyzed. On the basis of obtained dates the concentration dependencies of a saturation magnetization М_S of substance for a case are calculated, when the exterior static magnetic field is affixed in a plane of a sample. The concentration dependencies of absorption lines are analyzed.

NUCLEAR MAGNETIC RESONANCE AT THE COAL-METHANE SYSTEM

Degtyar S. E. 

281-284

Desorption of methane from persorption coal have a multistep nature. This is related to different forms of methane in the coal mass.

PREDICTION OF GAS AND ROCK OUTBURST SITES USING 1H NMR SPECTROSCOPY

Zavrazhin V. V., Gladkaya E. V. 

285-289

The prediction method has been developed based on this model and experimental research beginning from measuring intensities of wide and narrow lines in NMR spectrum of the coal samples. Intensities and widths of these lines characterize respectively numbers and energies of weakly or strongly bonded hydrogen nuclei in coal. An integral factor can be further derived from these data determining a gas dynamic condition of the coal massif in time and position. Growth of narrow-to-wide lines intensities ratio indicates approaching a potential outburst site. Implementation of this method in coal mines has revealed high reliability of ¹H NMR spectroscopy techniques in prediction of sudden coal and gas outburst sites.

DIELECTRIC CHARACTERISTICS OF BINARY SOLUTION INVESTIGATION USING SELF-EXCITED OSCILLATOR ON BASIS OF GUNN-EFFECT DIODE THAT STABILIZED OF PARTLY SHIELDED QUASI-OPTICAL DIELECTRIC RESONATOR

Kirichenko A. Y., Krivenko E. V., Lutsenko V. I. 

290-293

Q-factors of natural oscillations of partly shielded half-disk    dielectric resonator are investigated. Dependencies of frequency changing and steepness of self-excited oscillator electron tuning on basis of Gunn-effect diode, that stabilized of partly shielded quasi-optical dielectric resonator are obtained. Correlation between frequency changing of self-excited oscillation and steepness of electron tuning with real and imagine parts’ increase of matter permittivity is demonstrated.

PROPAGATION OF FEMTOSECOND PULSES ALONG LIGHTWAVE COMMUNICATIVE SYSTEMS

Yakushev D. A.

294-297

The influence of higher-order dispersive and nonlinear effects on propagation of pulses along optics fibers is investigated. An approach based on the Fokker-Planck equation using the first-order adiabatic perturbation theory is presented to study the statistical properties of parameters of ultrashort pulse in the presence of amplifier spontaneous emission. This method allows the direct reception of probability density function by solving the Fokker-Planck equation. In particular, the analytical calculation of the dependence of jitter of femtosecond soliton parameters on propagation distance is given. It can be concluded, that the influence of higher-order effects like nonlinear dispersion, third-order dispersion and intrapulse Raman scattering tend to increase the jitter of soliton parameters.

SPACE CHARGE WAVES’ INSTABILITIES AS A RESULT OF INTERACTION OF A NON-RELATIVISTIC ELECTRON BEAM WITH A LAYERED SEMICONDUCTOR CYLINDER

Rusanov A. F., Yakovenko V. M.

298-302

The paper presents a theoretical study of an electron beam interaction with electrostatic oscillations in a cylindrical system, which represents an electron beam surrounded by small-layered semiconductor material, that borders isolator or metal. Dispersion equations for various geometrical configurations are obtained in analytical form. The results of the analysis show, that interaction of a non relativistic electron beam with electrostatic oscillations of the layered medium gives rise to a broad band instability of space charge waves of the electron beam.

FIELD EMISSION PROPERTIES OF OFF-STOICHIOMETRIC SILICON OXIDES

Mazunov D. O.

303-308

The emission characteristics of the SiO_x (x ~ 0,3) thin film flat cathodes, produced by silicon thermal vacuum evaporation, have been investigated. It was shown that high temperature annealing (≥ 1000°C) of these films in inert ambient with further etching in HF solution sufficiently improves the emission properties: emission currents increase whereas threshold voltage is reduced. The explanation of electron field emission peculiarities from SiO_x surface is proposed. It was demonstrated that the limitation process of the current flow under high electric fields is Fowler-Nordheim tunneling. Current peaks in emission I-V characteristics are revealed. Most likely, they are caused by resonance tunneling mechanism.

COMPARATIVE ANALYSIS OF THE SINGLET EXCITED CONDITIONS XANTHENE AND OXAZINE DYES

Dalchenko P. G., Dzjubenko M. I., Pedash V. F., Pedash J. F. 

309-314

In the p-electron approximation calculations of the excited states of ionic forms of xanthene and oxazine dyes are carried out.   Electron transition energies, their polarisation and redistribution of electron density in the excited state are estimated. The use of charge transfer numbers allowed to establish a genetic bond of the singlet excited state of xantene and oxazine compounds. Quantative characteristics of the donor activity of the substituents (amino- and oxygroup) are obtained and their contribution to the formation of excited terms is determined by using of th localization numbers.

RESEARCH OF GAS HCN LASER OF THERAHERTZ FREQUENCY BAND WITH MALTERS EFFECT IN A HOLLOW CATHODE

Kiseliov V. K., Kuleshov Ye. M., Lapty V. K.

315-320

The aluminium oxids filmy hollow graphite cathode with anomalous secondary emission (Malter’s Effect) had complemety HCN laser of terahertz frequency band testing. Laser generation had to stationary regime in span 8 hours to last with current and voltage for dischargeous distance 0,8 m accordingly 0,5 A and 660 V. Temperature of the cathode was + 20°C.

THE SOLID-STATE TRANSMITTING-RECEIVING SYSTEM FOR VECTOR MESUREMENTS IN 2 MILLIMETER WAVE BAND

Ermak G. P., Varavin A. V., Kochergin V. P.

321-325

The results of development and investigation of the 2 mm-wave solid-state transmitting-receiving system for vector network analyzer are presented. The system is based on two active high-order IMPATT diode multiplying sources (master and slave) that are locked with PLL system. The amplitude, phase and spectral characteristics of the system are investigated.

COMPUTER-BASED COMPLEX FOR RESEARCH OF DIFFUSION PROCESSES IN METALS AND ALLOYS WITH RADIOACTIVE METHOD

Borodavka A. Y., Posukhov A. S., Semenenko V. Y., Stervoyedov S. N.

326-330

Development results of parameters of diffusion measurement technique in composite materials are submitted. Opportunities of the developed method are determined and experimental results of measurements of diffusion Ni⁶³ in monocrystal nickel and nickel-based alloys are given.

EFFECT OF COMBINED MGNETIC FIELDS ON PLANTS GRAVITROPIC REACTION AND ELECTROMAGNETIC IRRADIATON SPECTRUM GENERATED BY PLANTS DURING THEIR GROWTH

Sheykina N. V., Bogatina N. I., Kordyum E. L.

331-335

In the work the effect of combined magnetic field (CMF) on the gravitropic reaction (GTR) of 3-days cress roots in the frequency region 1-45 Hz has been investigated. The changes in the sign of GTR, its activation or inhibition and inhibition of roots’ growth were found at some fixed frequencies. The changes are resonance dependent on frequency. The frequencies for which the mentioned above effects were observed coincided formally with the ion  cyclotron frequencies for such ions: Са²⁺, К⁺, IAA^-, gibberillines ions, abscisic acid ions^-, Сu⁺, and with the frequencies for which the electromagnetic irradiation was observed before. The possible mechanisms of CMF effect on GTR are discussed.

PHASE-FREQUENCY METHOD OF HIGH FREQUENCY RESONANT MEASUREMENT OF COMPLEX PERMITTIVITY OF MATERIALS

Vichkan’ A. V., Melyanovsky P. A.

336-340

The phase variant of the resonance measurement method of complex permittivity of different substances on high frequencies is considered.