1. Identification and localization of radar impulses buried in noise A. G. Tyzhnenko, Y. V. Ryeznik radar, pulse, identification, localization, low SNR Vestnik KhNU ¹806 Pages. 7074
Statistical method identification and localization of radar impulses buried in noise is addressed. To this end, the correlation coefficient between carrier samples measured in the extremal points and analogous set of points of received signal is proposed to implement. Such measurements for receiving signal need to be done at least by one tenth of the half period of the carrier. Because of very simple algorithm proposed, such measurements do not lead to heavy computational burden. To decrease identification and localization errors for given signal to noise ratio (SNR) one needs to increase the number of measurements points, and hence, the pulse width. To prevent this issue, one can increase the carrier frequency. In general, the method accuracy increases with the carrier frequency. The method proposed permits theoretically to identify with fidelity impulses buried in noise for SNR lower than 30 dB.
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2. Impact of random variations of air hole diameters and random variations of the centers position of air holes on operation parameters of a solid core microstructured optical fiber A.I. Filipenko, A.N. Donskov finiteelement method, Gaussian distribution, inclusions diameter, total mode field power, angular positioning, microstructured optical fiber. Vestnik KhNU ¹983 Pages. 2932
We investigated the impact of random variations of air hole diameter and random variations of the centers position of air holes on operation parameters in the case of solid core microstructured optical fiber with a ring of air holes. The found results show that at any of considered defect types mode field will have two pronounced maximums. At practical use an investigated type of the MOF special angular positioning end faces of fibers is necessary. We also have shown that random variations of inclusions diameter can increase total mode field power. In our research we used finiteelement method.
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3. Impedance characteristics of planar diodes with tunnel boundaries based on GaAs Prokhorov E.D., Botsula O.V., Klimenko O.A. : negative differential conductivity, tunnel boundary, a diode, the tunneling. Vestnik KhNU ¹966 Pages. 1318
The impedance characteristics of the diodes are consider, which negative differential conductivity (NDC) is arise under certain voltage, due to tunneling of electrons through the side faces of the diode, which can be used for generation, amplification and multiplication. Depending on the active and reactive components of impedance are determined of the diode with the tunnel boundaries for the real parameters of the diodes. It is shown that the limiting frequency of the diode NDC is in the terahertz range and depends on its parameters.
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4. Impedance of connected in series diodes with difference negative conductivity E.D. Prokhorov tunnel diode, negative conductivity, frequency range Vestnik KhNU ¹712 Pages. 111114
The impedance connected in series negative difference conductivity diodes in wide frequency range are analyses. There are frequency region that diodes combination work have been appeared. The operation frequencies for combination of tunnel diodes are 3540 GHz
5. Increase of free volume 0f the aip abundant in the water by the millimeter waves of low intensity B. G. Yemets electromagnetic waves, air bubbles, field of temperature, convection Vestnik KhNU ¹806 Pages. 103106
Using an NMR technique the volume growth of the free ("bubble") air contained in water caused by lowintense electromagnetic waves is obtained. This change is caused by rectified diffusion of the dissolved air mass into bubbles. The increase in the free air may occure only under those conditions when there is no convection in the liquid, i. e. in the case of irradiating by means of lowintense waves.
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6. Influence of apertureillumination law on nearfield characteristics of aperture antennas E.E. Ovsyannikova, A.V. Shishkova, N.N. Gorobets electromagnetic waves, reactive fields, aperture radiators, Kirchhoff technique, nearfield, farfield, amplitude distributions, phase characteristics, amplitude characteristics, reactive radiation power Vestnik KhNU ¹853 Pages. 2836
On the basis of Hertz potentials the investigation of nearfield reactive region of square aperture antennas with various aperture illumination laws has been carried out. The influence of the field amplitude distribution law in the aperture on the extension of this region has been studied. The calculation and analysis of amplitude, phase and power radiation characteristics, including reactive radiation power density, at the different planes in nearfield region have been carried out. The analysis of the criteria for estimation of nearfield reactive region boundary has been carried out
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7. INFLUENCE of ENVIRONMENT ON the FIELD, SCATTERING ON the LATTICE WITH LAYER, AT ANY FALL of the WAVE A.I. Adonina, V.B. Khokh lattice, environment, dielectric, a stream of capacity, method of RimanHilbert problem Vestnik KhNU ¹756 Pages. 5156
The decision of a task in view is carried out for Å and Í the fields appropriate to two subsystems on which the system of the equations of the Maxwell for environments is divided. Integrated characteristics of a field are determined from the decision of systems of the linear algebraic equations received by a method of method of RimanHilbert problem , for a case when the smallest parameter decreases in inverse proportion to a square n>infinity. Programs (fort) with construction of diagrams are made. The analysis of the diagrams in part given in work, allows to establish influence of parameters of structure and corners of fall of a wave on anomalies in an absentminded field for each concrete case
8. Influence of impact ionization on efficiency of rscadiodes operation on basis of InN, GaN, AIN D.V. Pavlenko, E.D. Prokhorov nitrides, RSCA oscillators, oscillating efficiency, drift velocity Vestnik KhNU ¹756 Pages. 109112
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 %)
9. Influence of shading of the radiating aperture of singlereflector antenna by focal module on directional characteristics Gorobets N.N., Kiyko V.I. microwaves, reflector antennas, reflector shading, directional characteristics Vestnik KhNU ¹966 Pages. 97102
The effect of shading of the radiating aperture singlereflector parabolic antenna on radiation pattern, gain, wide beamwidth and sidelobe levels while changing the focal length of the relationship to the diameter of the reflector in the range of 0.5 to 1.5 takes place was theoretically investigated. Thus, it was shown that the effect of shading on all directional characteristics is the less than the longerfocused is the reflector. The minimum level of side lobes is in the case of shortfocused reflector
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10. Inner partial mutual admittance of two overlopping longitudinal slots in a rectangular waveguide with dielectric layer parallel to narrow walls A.A.Lyakhovsky, L.P.Yatsuk, A.F.Lyakhovsky , layer, dielectric, slot, admittance, scattering parameters Vestnik KhNU ¹853 Pages. 2227
The expression for the partial inner mutual admittance of two longitudinal slots overlapping along waveguide longitudinal axis is obtained. The slots are cut in a broad wall of a rectangular waveguide filled with threelayered dielectric. The excitation problem is solved with the modified eigen waves method. As eigen waves of the LE and LM modes are chosen. The field in the source region includes the potential functions as well. Dependences of inner mutual admittance and scattering parameters on distance between two slots and frequency are investigated. The system scattering parameters calculated are in a good agreement with experimental data
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11. Integral representation of green function in parallelplate and rectangular waveguide, and in resonator as well V.A. Katrich, F.S. Novokhatsky waveguides, Green function, fundamental solution, radial function, elliptical teta function, image method, calculus of residues, integral transformation, grating, formal variative Vestnik KhNU ¹712 Pages. 6770
The known results connected with Green function representation by elliptical thetafunction are generalized. New representations of Green function for some widely used types of waveguides are obtained. Earlier, these Green functions are presented either in form of series with nonuniform convergence or in form of integrals containing Hancel functions, which are reduced to asymptotic expressions in far zone. On this work integral representations of Green functions are obtained for Cases where the quadrature formula exists. The method of analytical continuation with parameter is applied
12. Investigation of different temperature modes of auxilliary cathode work in magnetrons with cold secondaryemission cathode Avtomonov N.I., Vavriv D.M., Sosnytsky S.V. Magnetron, cathode, thermionic cathode, thermo emission, temperature Vestnik KhNU ¹883 Pages. 7382
A theoretical investigation of the emission current temperature dependence of the auxiliary cathode in magnetrons with cold secondaryemission cathodes is performed. Different methods of providing a spatialcharge limited emission from the auxiliary catho
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