1. GAUSSIAN EXPANSIONS FOR RADIATION PATTERN OF AN OPEN-ENDED LINE WITH IMPEDANCE BORDERS
aperture distribution, impedance border, Orthogonal functions, diffraction integral, feed
Vestnik KhNU ¹756 Pages. 87-90
Near-field and far-field two-parameter expansions in terms of Laguerre-Gaussian orthogonal basis functions are proposed, which take into account the effect of impedance feed borders. The expansions enable the feed characteristics on a base of lines with impedance borders to be calculated in wide frequency region. Radiation intensity distributions for the open-ended two-layer metal-shielded dielectric waveguide in a nonresonance regions of surface impedance varying, relative errors of expansion truncations, comparison with experimental data are presented
2. Al0,3Ga0,7As/GaAs cathode transfer electron diode's efficiency
O.V. Botsula Prokhorov E.D, A.V. Dydchenko
doping, cathode contact, tunnelling, negative differential conductivity, Oscillation efficiency
Vestnik KhNU ¹756 Pages. 97-100
The results of analyse efficiency of GaAs/ Al0,3Ga0,7As/GaAs GaAs/ Al0,3Ga0,7As/GaAs / GaAs cathode transfer electron diode are present. The space charge model are used. There are two region of negative differential conductivity of current - voltage characteristic are shown . The condition lead to oscillation due both region and oscillation efficiency have been determined.
3. Wide range mm-wave GAAS- oscillator with electronic frequency gliding
A.V. Dyadchenko, E.D. Prokhorov
Oscillators, electronic frequency gliding, Oscillating efficiency
Vestnik KhNU ¹756 Pages. 101-104
The wide range mm - wave GaAs oscillators with electronic frequency gliding are considered. The oscillator is operated up 60 to 70 GHz on second harmonic. The electronic gliding is perfomed to obtaine of 9 GHz change of frequency
4. AlN/AlxGa1-xN resonance tunnell diodes
D.V. Pavlenko, E.D. Prokhorov
nitrides, quantum well, NDC, Oscillation efficiency.
Vestnik KhNU ¹756 Pages. 105-108
Double and threefold compounds of nitrides AIN/AIGaN resonance tunnel diodes using height of barriers are concedered. In the quantum well of diodes there are a plenty energy levels. Electron energy levels in quantum well with variable structure of interconnections AlGaN are determined. The current - voltage characteristics of resonance - tunnel diodes with number of levels in a quantum wall up to five has been calculated. The RTD can have up to five sites with negative differential conductance are demonstrated. The possible RTD oscillation efficiency on all sites of negative differential conductivity at difference barriers and quantum well's material are determined.
5. Influence of impact ionization on efficiency of rsca-diodes operation on basis of InN, GaN, AIN
D.V. Pavlenko, E.D. Prokhorov
nitrides, RSCA oscillators, Oscillating efficiency, drift velocity
Vestnik KhNU ¹756 Pages. 109-112
The impact ionisation in RSCA diodes is considered on the basis of nitrides InN, GaN, AIN. Possible overvoltage on diodes and possible efficiency of generation are analyzed. It is shown, that at development of a impact ionisation in RSCA diodes in correspondence with the diffusion theory the considered materials are perspective for RSCA diodes for operation in centimeter and millimeter wavebands (voltage over threshold 3 ... 5 at efficiency up to 11 ... 13 %)
6. RECTANGULAR WAVEGUIDE M.V.
millimeter range, parametric amplifier, Oscillatory system, band of the reinforcement, relative noise temperature
Vestnik KhNU ¹806 Pages. 18-21
Semiconductor two-stage parametric amplifiers have been developed to be used in the input circuits of communication and navigation systems in the short-part of millimeter wave band. In the 60 to 65 GHz range, the gain is no worse than 15 dB at -3 dB level in 1 to 1.6 GHz bandpass. The noise temperature is no higher than 500K when the quasi-optical IMPATT oscillator is in using as the pumping generator.
7. Oscillation efficiency of TED diodes on the basis of nitrides
E. D. Prokhorov, O. V. Botsula, A. N. Zabazhan
AlN, GaN, InN-diodes, drift speed, Oscillation efficiency
Vestnik KhNU ¹853 Pages. 15-21
Oscillation efficiency of intervalley transfer electrons diodes on the basis of nitrides (InN, GaN, AlN) is considered. Electric fields at peak oscillation efficiency are determined. The results have been compared to results for GaAs. The account of floatable potential in connections InGaN improves their power characteristics in comparison with power characteristics of these connections without taking into account floatable potential, maximal efficiency In0.8 Ga 0.2 sub>N and In0.5Ga0.5N diodes to compare to InN diodes on 30 % is higher (22 % to compare to 16,43 %) but at more high tensions of an electric field. The maximal oscillation efficiency is observed at higher electric fields than GaAs ( from 250 êV/sm for InN to 1000 kV/sm for AlN)
8. Algorithms of the processing signal from the trellised receiver for measuring of the laser radiation characteristics
Kokodiy N.G., Pak A.O.
the laser, Optical radiation, intensity, bolometer, direct task, reverse task
Vestnik KhNU ¹853 Pages. 37-44
In this paper has been considered the development of the device for the measurement of the intensity distribution in the beam of optical radiation. The algorithm of processing of a signal from the receiver of radiation is studied. The method of measurement of the intensity distribution of optical radiation by the bolometric grid is offered. The developed algorithms for processing a signal from the measuring converter and programs realizing them are checked up experimentally, their serviceability is confirmed. The comparative characteristic of algorithms based on the transformation of Fourier and transformation of Radon has shown an opportunity of their use in practice
9. Random inhomogeneous liquid medium as a continuous laser of low-intensity modulator for excitating sound in the medium
B. G. Yemets
laser, random inhomogeneous liquid medium, interference, temperature field, Optical acoustical phenomenon, sound, excitation, modulation
Vestnik KhNU ¹853 Pages. 95-100
When a medium is irradiated by laser pulses, sound waves are excited in this medium, i.e., the well-known optical acoustical phenomenon occurs. To excite sound oscillations, the specific laser beam modulator is shown to be unnecessary. The role of the modulator can play the liquid itself, which is a random inhomogeneous medium. The real liquid contains suspended solids and gas bubbles of small dimensions (dust particles and the like) that move irregularly in space (fluctuations). As a result, the electromagnetic wave interference taking place in the liquid undergoes random changes. Consequently, the temperature field changes, and hence variations in the local pressure occurs (thermo-optical mechanism for exciting sound). The excitation of sound due to the laser irradiation of low intensity is observed in an increase in the gas bubbles dimensions in the liquid
10. Construction of mode basis for open dielectric structures by integral equation method
Legenkiy M.N., Butrym A.Yu.
mode basis method, Open waveguide, eigenmode
Vestnik KhNU ¹883 Pages. 50-53
A new method based on integral equation formulation is proposed for construction of mode basis in open dielectric waveguides. Decomposition of the spectrum in such structures into discrete (surface wave) and continuous (volume wave) part is analyzed. Disp
thermal nonlinearity, Optical beam, total reflection, induced inhomogeneity, self-defocusing.
Vestnik KhNU ¹983 Pages. 33-37
The interaction of optical beams in media characterized by a refractive index depending on temperature is examined. The optical pump beam is partially absorbed by the medium induces a region with an inhomogeneous refractive index. As a result complete reflection, refraction or diffraction of the signal beam on the induced optical inhomogeneity may be observed. Experimental results on the research of this phenomenon are presented. Waveguide propagation of light in the region formed by two narrow pump beams is realized.
Optical element of the cylindrical form, light scattering, Monte-Carlo method, indicatrix of scattering, index of refraction
Vestnik KhNU ¹983 Pages. 67-71
Modeling of characteristics of optical spectral-selective elements of the cylindrical form with the increased value of the refraction index, using effect of light scattering is organized. The parameters of the optical element materials, forming its spectral-selective characteristic are determined. As have shown results of researches, application of cylindrical optical element for spectral angular selection is possible in limited range of values of the index of refraction. At increase in value of refraction index before determined level the optical element starts to function in a mode of quasi uniform light scattering.
gravimeter, superconducting suspension, Optical registration, thin films, superconducting ring.
Vestnik KhNU ¹983 Pages. 107-113
This paper considers the problem of designing and developing optical-cryogenic devices using new physical principles, mathematical methods, and new superconducting materials. The sensor element is based on new ñontrolled magnetic levitation phenomenon, high-precision optical registration of mechanical coordinates of levitating body, and the robust signal processing tools. A controlled self-bearing probe dynamics is also analyzed. We have shown how to produce reliable YBCO thin films with controllable surfaces and physical properties and how to integrate them in a ring form into the optical-cryogenic gravimeter so as to reduce its size and render it convenient for future space applications.
laser, Optical radiation, intensity, distribution, receiver, direct problem, inverse problem.
Vestnik KhNU ¹927 Pages. 31-35
In this paper has been considered the method of the measurement of the intensity distribution in the beam of optical radiation and the algorithm of processing of a signal from the receiver. The method is using the knife attenuator of the special shape. The power of the reflected radiation on knife was measured by using detector of photoelectric. The algorithm and program for handling of the signal from receiver are developed. The influence of errors in the measurement signal from the receiver on the results of calculations has been researched. The experiment has confirmed the serviceability of the method and the possible of their use in practice.
founded: 14 result (s)