V.F. Kravchenko and V.A. Rvachev

AWavelet Systems and Their Applications in Signal Processing

Since the study of wavelets is a relatively new area with much of the research coming from mathematicians, most of the literature uses terminology, concepts, and proofs that may, at times, be difficult and intimidating for an engineer. In this review, we suggest a new mathematical method for the wide class of problems in signal processing.

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V.M. Bezruk
Kharkov National University of Radio Engineering and Electronics,
14, Lenin Ave, Kharkov, 61166, Ukraine
Recognition Methods Based on Autoregression Model of Signals

Some practical features of methods of recognition of random signals based on signal description by an autoregression model are considered. The algorithms presented in the article are characterized by smaller computing temporal cost as compared with the Bayessian classifier that is practically unrealizable at the considerable dimension of the initial description and at the finite volume of the learning samples of signals. A comparative analysis of signal recognition quality is made for various recognition algorithms by a statistical simulation method.

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M.A. Basarab and V.F. Kravchenko

The Use of Atomic Functions in the Filtered Backprojection Algorithm for Reconstructing Tomographic Images

The use of the new class of weighting functions (windows) based on atomic functions in the filtered backprojection algorithm for reconstructing tomographic images is considered in the article. Atomic interpolation and quasi-interpolation procedures are used at the intermediate stage of the algorithm.

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A.V. Kobzev and A.N. Bovkun
Kharkov Military University
The Statistical Characteristics of Fast Signal Fluctuations and Their Analysis Based on the Simulation Model of Long-Distance Tropospheric Wave Propagation

The simulation model for a long-distance tropospheric wave propagation (LTP) is discussed. The input data for the model are as follows: a carrier frequency, type of modulation, distance of communication, etc. The model is intended to estimate the statistical characteristics of signals traveling through the LTP channel, i.e. an autocorrelation function of the signal envelope, the wavelength-dependent radius of the envelope correlation, power pulse response, frequency correlation function, instantaneous patterns. The simulation results are compared to the characteristics that were obtained experimentally and cited in the literature.

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S.B. Panin and A.Ye.Poyedinchuk
A. Usikov Institute for Radiophisics and Electronics Natonal Academy of Sciences of Ukraine
12, Academiccian Proskura St., Kharkov, 61085, Ukraine
Polarization Properties of a Screened Chiral Layer with a Diffraction Grating

The paper concerns with polarization characteristics of the reflecting structure which represents a dielectric layer and chiral layer between a diffraction grating and screen. Owing to the analytical regularization procedure, the diffraction vector problem is solved in the form admitting effective numerical investigation. It is shown that in particular cases the incident plane-polarized field may be fully converted to the specular reflection field of cross-polarization. The effects which the grating and the grating-screen resonant space exert on the polarization conversion character are recognized. The mechanism of polarization conversion is understood, and possibilities for enhancing conversion efficiency and broadbandness are demonstrated.

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V.A. Doroshenko and E.K. Semenova
Kharkov National University of Radio Engineering and Electronics,
14, Lenin Ave, Kharkov, 61166, Ukraine
Electromagnetic Wave Diffraction by a Longitudinally Slotted Cone

A semi-infinite, perfectly conducting circular cone with slots cut periodically in the lateral surface along the generatrix is analyzed for the case of excitation by a radial magnetic dipole. The solution algorithm for the electrodynamic, boundary-value problem is based on application the Kontorovich-Lebedev integral transformation which reduces the problem to a singular integral equation with a Cauchy type kernel. A numerical experiment has been performed to analyze the Fourier coefficients of the field components in dependence on the angular size of the conic structure.

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S.L. Berdnik, V.A. Katrich, N.A. Lyashchenko, and N.A. Polyanov
V. Karazin Kharkov National University,
4, Svoboda Sq., Kharkov, 61077, Ukraine
Energy Characteristics and Directed Properties of Electrically Long Longitudinal Slots in a Rectangular Waveguide

A study has been made into the long extended slots cut through in the wide wall of a rectangular waveguide by using the magnetomotive force (MMF) method. As part of the numerical calculations being performed, the waveguide wall thickness has been taken into account. A computer-aided analysis suggested that in terms of using the extended slots the energy characteristics of the leaky-wave antennas could be optimized.

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S.I. Khankina, V.M. Yakovenko, and I.V. Yakovenko
A. Usikov Institute of Radio Physics and Electronics, National Academy of Sciences of Ukraine
12, Academician Proskura St., Kharkov 61085, Ukraine
Energy Losses of a Charged Particle Due to Exitation of Helicons in Solid-State Plasma

The energy losses of a particle moving along the spiral relative to the direction of the constant magnetic field, due to the Vavilov-Cherenkov radiation of helicons, have been studied. It has been found that these losses are equivalent to the energy losses of the magnetic moment produced by rotation of a charge. In this case the magnetic moment is moving at a constant velocity along the magnetic field. It has been shown that the Vavilov-Cherenkov radiation of the magnetic moment forms the basis of the collisionless damping of helicons.

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N.N. Beletskii and Yu.V. Bludov
A. Usikov Institute of Radio Physics and Electronics, National Academy of Sciences of Ukraine
12, Academician Proskura St., Kharkov 61085, Ukraine
Nonlinear Surface Polaritons in a Two-Dimension Electron System Plased in an External Quantizing Magnetic Field

Nonlinear surface polaritons (NSP) have been investigated theoretically in an isolated two-dimension electron system located at the boundary between two nonlinear media and placed in an external quantizing magnetic field directed transversely to the two-dimension electron system. It has been assumed that the dielectric permittivity of nonlinear media is a quadratic function of the electric field tangential component. We have shown that under conditions of the integer quantum Hall effect, all characteristics of the NSPs are represented by quantized values. It has been found that NSPs can exist only in the case when the value of the electric field tangential component at the boundary is less than a certain critical value. We have ascertained that in the case of the presence of a two-dimension electron system at the boundary, there are four modes in the spectrum of the NSPs. Two of them are characterized by a normal dispersion and two others possess an anomalous one. It has been shown that the modes of the NSPs with an anomalous dispersion exist only at small values of the wave number. We have found that in the case of symmetrical surrounding of the two-dimension electron system, there are only two modes in the spectrum of the NSPs.

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L.I. Sviderskaya
Kharkov National University of Radio Engineering and Electronics,
14, Lenin Ave, Kharkov, 61166, Ukraine
Theory of Semi-Conducting Structure--Microwave Field Interaction in a Resonant Cavity

A mathematical model is developed of the impact of inhomogeneously doped semiconductor structures on the electromagnetic field of microwave resonant measuring transducers. The model allows for the effect of losses in the sample on the field perturbation. The algorithms developed after the mathematical model permit studying variations in characteristic parameters of the measuring cavity, practically with any law of admixture distribution over the specimen thickness.

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S.P. Martynyuk, A.P. Motornenko, K. Schunemann, and I.G. Skuratovskiy
A. Usikov Institute of Radio Physics and Electronics, National Academy of Sciences of Ukraine
12, Academician Proskura St., Kharkov 61085, Ukraine
Performance of a Microwave Plazmatron with Nonequilibrium Plasma

The energy characteristics of a microwave coaxial plazmatron with nonequilibrium plasma excited by CW microwave power on 10 GHz (tree-centimetric waves) have been investigated. Argon has been used as plasma forming gas flowing out into the ambient space. It is seen that the power transfer coefficient into the plasma load increases with increasing the generator power. Depending on the consumption of argon the minimal powers for the maintenance of a steady torch discharge have been obtained for two ways of argon supply in the discharge region.

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À.Ya. Kirichenko, A.P. Motornenko, and O.A. Suvorova
A. Usikov Institute of Radio Physics and Electronics, National Academy of Sciences of Ukraine
12, Academician Proskura St., Kharkov 61085, Ukraine
Influence of a Plasma Forming Gas Jet on the Discharge Structure in a Microwave Plasmatron

The dynamics of structural changes of a discharge in a microwave plasmatron at its transition from a filament to a torch, occurring due to change the parameter of a plasma forming gas jet has been studied in the paper. The behavior of the maximal electrical field magnitude in a discharge cross section has been found.

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V.A. Antonova, V.N. Borshchov, V.A. Zolotarjov, A.M. Listratenko, and N.I. Slipchenko
Kharkov National University of Radio Engineering and Electronics,
14, Lenin Ave, Kharkov, 61166, Ukraine
Optimization of Silicon Solar Cells Based on the n+-p-p+ Structures

Methods and results of calculation of optimal conditions for diffusion of phosphorus into silicon from glassy films, ensuring a specific doping profile in the frontal junction, are presented. The n+-p frontal contact net parameters are optimized. The obtained results allow photo-transformation optimal conditions to be provided.

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A.V. Vichkan and P.A. Melyanovcky
A. Usikov Institute of Radio Physics and Electronics, National Academy of Sciences of Ukraine
12, Academician Proskura St., Kharkov 61085, Ukraine
Measurement of Complex Dielectric Permittivity of Water Solutions in High-Frequency Band

The impedance method has been considered for the measurement of a dielectric permittivity and losses of water solutions of salts in the high-frequency band. The complex dielectric permittivity of solutions with different concentrations has been measured. The usefulness of the method for measuring dielectric parameters of well-conducting water-containing media has been demonstrated.

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