| V.V. Dolzhikov and Y.P. Gorelov
Kharkov National University of Radio Engineering and Electronics, 14, Lenin Ave, Kharkov, 61166, Ukraine Mean Characteristics of a Circular Aperture with a Tapered Amplitude Distribution The effect of phase fluctuations in the exciting field upon parameters of the mean power pattern is analyzed for a circular aperture with a decreasing amplitude distribution and uniformly distributed phase. The parameters in question are the mean radiated power in the main lobe, the mean beam width, and the side lobe level. It is shown that the reduction of the side-lobe level through the use of a decreasing amplitude distribution in the antenna becomes less efficient in the presence of fluctuations, even with small values of its variance. Formulas are derived to evaluate the width of the mean power pattern, and dependences are presented graphically to estimate the level of two first side lobes for a wide range of variances and correlation lengths of phase fluctuations. |
| K.-H. Jeong* and A.S. Petrov**
*Microface company, Korea **Moscow State Institute of Electronics and Mathematics Broad Bandwidth Matching of Rectangular Microstrip Antenna Elements The bandwidth characteristics of rectangular microstrip antenna elements were investigated with the use of the model of an equivalent transmission line resonator and the theory of synthesis of electrical filters on the basis of low-pass prototypes. The compact expressions allowing to calculate relative band-width of microstrip antennas with multi-sectional filter-type matching circuits mounted at their inputs were obtained. The expression for account of theoretically limiting band-width of microstrip antenna elements is presented. The example of synthesis of a matching circuit realized on a basis of the three-section band-pass filter is given. |
| S.D. Andrenko, I.A. Vyazmitinov, and Yu.B. Sidorenko
A. Usikov Institute of Radio Physics and Electronics, National Academy of Sciences of Ukraine 12, Academician Proskura St., Kharkov 61085, Ukraine Antenna System of Continuous-Wave Radar A description is given of the antenna system of an L-band continuous-wave radar. The transmitting and receiving antennas are the cylindrical spirals with the oppositely directed windings, where the spacing between the axes can be compared to a definite wavelength. The basic antenna parameters have been determined experimentally. The receive-transmit channel isolation is 75 to 80dB over the 18% frequency band with respect to the central value. |
| A.N. Roenko, B.D. Zamarayev, V.L. Kostina, and V.F. Timoshenko*
A. Usikov Institute of Radio Physics and Electronics, National Academy of Sciences of Ukraine 12, Academician Proskura St., Kharkov 61085, Ukraine *V. Karazin National University of Kharkov, 4, Svoboda Sq., Kharkov, 61077, Ukraine Radio Wave Scattering in the Millimeter Band by Vegetation Canopies Results are presented of studying in the “water cloud” model, the scatter of electromagnetic power by a surface covered with vegetation. The vegetation considered was lawn grass. One of the possible approaches to solving the inverse problem is analyzed, namely evaluation of weight indices for the canopy from measured magnitudes of conductivity. |
| V.A. Katrich and M.V. Nesterenko
V. Karazin National University of Kharkov, 4, Svoboda Sq., Kharkov, 61077, Ukraine Power Characteristics of Electrically Long Longitudinal Slots in Rectangular Waveguides Analytical equations were obtained for the distribution functions of the magnetic current and power characteristics for longitudinal slots in rectangular waveguide. Solutions are correct for electrical slot length up to 2l in a free space. The comparison between computed results and experimental ones was carried out. |
| V.N. Mizernik* and N.I. Pjatak**
*Scientific physical and technological center, 1, Novgorodskaya St., Kharkov, 61145, Ukraine **V. Karazin National University of Kharkov, 4, Svoboda Sq., Kharkov, 61077, Ukraine Resonance Wave Scattering in a Tee-Junction of Waveguides Loaded with Cross-Magnetized Ferrite The findings of studies on H10-wave scattering on the cross-magnetized ferrite resonator in a T-junction of rectangular waveguides are presented. An analysis has been done in terms of rigorous solving the diffraction problem by the method of partial domains along with isolation of the region of connection and the biorthogonality conditions of eigenfunctions for the gyrotropic-filled transmission lines. |
| A.V. Gritsunov and L.Y. Turenko
Kharkov National University of Radio Engineering and Electronics, 14, Lenin Ave, Kharkov, 61166, Ukraine Harmonic Decomposition of an Exciting Current in Simulation of the Electron Devices The application of parametric method of spectral analysis for an exciting current harmonic decomposition in non-stationary and spectral models of electron devices is suggested. This is known as harmonic interpolation or original Prony method. The expansion in undamped complex exponential series is preferable for required purpose. The frequency resolution of proposed approach is far better comparing with the usual Fourier decomposition, especially for short time series. Some features of the method described are explored. The examples of its implementation and demonstrational code are given. |
| V.V. Danilov
Donetsk National University 24, Universitetskaya St., Donetsk, 83055, Ukraine Testing of Acoustooptical Components of Computing Means The design and development concepts of the time-domain data decompaction acoustooptical device for optical computing means based upon the acoustooptical cell operating a standing acoustic wave are suggested. A mathematical model describing the interaction between the fields of acoustic and light waves in this type of cell is presented. The breadboard construction (special-purpose prototype version) of acoustooptical time-domain data flow decompaction with a 3816 Gbit/s throughput at the two-polarization initial compaction has been investigated. The structures of conceivably realized acoustooptical time-domain data compaction and decompaction devices are proposed. |
| B.M. Bulgakov and M.P. Natarov
A. Usikov Institute of Radio Physics and Electronics, National Academy of Sciences of Ukraine 12, Academician Proskura St., Kharkov 61085, Ukraine Efficiency of Excitation of Open Resonance Systems A simple model of a hemispherical open resonator has been used to consider the process of its excitation by local sources. An effect produced by displacing the source from the resonator axis and the influence of the loaded Q-factor magnitude have been investigated. It is shown that synchronous excitation of the resonator by several local sources results in improved excitation efficiency. The synchronous excitation of the resonator offers a certain advantage in power if it is excited by several local sources. This makes for the mutually synchronized operation of self-excited oscillators located in the common resonator. |
| A.I. Arkhipov, O.I. Belous, A.P. Koretskiy and A.I. Fisun
A. Usikov Institute of Radio Physics and Electronics, National Academy of Sciences of Ukraine 12, Academician Proskura St., Kharkov 61085, Ukraine Millimeter-wave Solid-State Oscillator with Elliptical Open Resonator The paper presents the results of experimental research of quasi-optical solid-state oscillators (SSO) with 8-millimeter (8-mm) band Gunn diodes using a stabilizing ellipsotoric open resonator (ETOR). The prospect of applying such devices for improving the output parameters of solid-state sources of radiation within the millimeter-wave bandwidth has been demonstrated. |
| D.N. Makovetskii
A. Usikov Institute of Radio Physics and Electronics, National Academy of Sciences of Ukraine 12, Academician Proskura St., Kharkov 61085, Ukraine Nonlinear Dynamics of the Phonon Stimulated Emission in Microwave Solid-State Resonator of the Nonautonomous Phaser Generator The microwave phonon stimulated emission (SE) has been investigated in a solid-state resonator of a non-autonomous acoustic quantum generator (phaser). Branching and long-time refractority (absence of the reaction on the external pulses) for deterministic chaotic and regular processes of SE were observed in the experiments with weak and strong electromagnetic pumping. The clearly depined increase of the number of the independently co-existing SE states as the pumping level rise has been observed both in physical and computer experiments. This confirms the analytical estimations of the branching density in the phase space. The nature of the SE pulses refractority is closely connected with such branching and reflects the crises of strange attractors, i.e. their collisions with unstable periodic components of the higher branches. |
| O. V. Gurin, A.V. Degtyarev, V. A. Maslov, V. A. Svich, V. M. Tkachenko, and A. N. Topkov
V. Karazin National University of Kharkov, 4, Svoboda Sq., Kharkov, 61077, Ukraine A Waveguide Submillimeter Laser with Mode Selector An optically pumped submillimeter laser on a basis of the quasioptical waveguide resonator with mode selector is investigated experimentally. It is shown that the proposed method for the selection of transverse modes by an iris diaphragm on the plane mirror of a system of deflecting mirrors allows one to ensure the effective suppression of higher oscillation mode when operating of a laser in a wide spectral range. |
| M. M. Bykov and I. M. Rudchenko
Kharkov National University of Radio Engineering and Electronics, 14, Lenin Ave, Kharkov, 61166, Ukraine Kinetic Process Simulation in Lasers with the Nonlinear Modulators and Static Parameters The results of quantitative and qualitative investigations of one-dimensional mathematical model of the laser with in-cavity nonlinear (phototropic) modulator are presented. Investigation was carried out by calculating of a grid of working points on the diagram of the model stability. The result of modeling is the family of curves describing the development kinetics of radiation intensity, and inversions of the active and passive media. The system is partially analytically solved for the period before the generation. The equations for the equiinterval curves (curves of equivalent intervals between generation pulses) were obtained from the analytical time equations of inversion development. |
| S.N. Savenkov and K.E. Yushtin
Kiev National University Optimization of a Dynamic Polarimeter for the Incomplete Mueller Matrix Measurement The possibilities for using a dynamic polarimeter (PD) intended to measure incomplete Mueller matrices (MM) are analyzed. A variety of these matrices which can be measured by the dynamic polarimeter is found. The accuracy-related characteristics of the specific operating modes of the PD are estimated. |
| V.M. Kuzmichov and S.V. Pogorelov
V. Karazin National University of Kharkov, 4, Svoboda Sq., Kharkov, 61077, Ukraine Calibration of Thin-Wire Platinum Bolometers for Pulsed Laser Power Measurements A technique is justified for calibrating thin-wire platinum bolometers intended for measurements of pulsed radiation power at the wavelength of 10.6 micrometer. The technique is based on the use of known temperature dependences of the specific resistance and specific heat capacity for determining the temperature dependence of the absorption efficiency factor. The heat balance equation with variable coefficients is averaged over the bolometer length and then solved for a non-uniform distribution of the incident power. |
| À.I. Filipenko
Kharkov National University of Radio Engineering and Electronics, 14, Lenin Ave, Kharkov, 61166, Ukraine The Fiber Connector End Monitoring with the Interference Method The free-contact monitoring method of optical connector end face grain based on the interference picture analisis is described. The interference image is formed in the Linnik microinterferometer and directed to the matrix CCD videocamera. The video signal is transformed by analog-to-digital converter to a two-dimensional brightness code array of interference picture points. The control of the system is carried out with the personal computer. The high-frequency noise rejection is performed using a two-dimensional digital filter in the spatial frequencies region. The technique of fringe curvature degree estimation is based on the row analisis of fringe points appropriate to the maximum of intensity. The value of a grain is estimated according to the program displacement with a spatial filter-window moving along the maximum. |
| B.G. Yemets
V. Karazin National University of Kharkov, 4, Svoboda Sq., Kharkov, 61077, Ukraine Effect of Alternating Electric Fields on Liquid Dielectric Dispersed Systems Based on the model considerations it was shown that irradiation of liquids containing dispersed dielectric inclusions with electromagnetic fields of "non-convective" intensity is conducive to the changes in the inclusion size. |