1. THE INFLUENCE OF MUTUAL COUPLING ON RADIATION CHARACTERISTICS OF ANTENNA ARRAY FOR VIDEOPULSE EXCITATION
mutual coupling, finite TSA arrays, Van-Atta array, Videopulse
Vestnik KhNU ¹756 Pages. 57-60
In paper antenna array from finite number of the elements, which are exited by a videopulse is observed. The model for calculation of radiated fields of antenna taking consideration of mutual coupling between elements is proposed. A directed characteristics analysis of the retrodirected systems, Van-Atta array, from finite number of elements and wave form of radiated and reradiated signals are investigated in case of excitation by a videopulse. Recommendations to decrease mutual coupling is proposed. The case of useful influence on characteristics of a radiated pulse signal is considered
2. Application of the digital holographic interference microscope for investigation of thin films
D.N. Tishko, T.V. Tishko, V.P.Titar, Yu. A. Zadneprovskiy, A.S. Kuprin, I.A.Zgoda
digital holographic interference microscope, three-dimensional images, Vacuum-arc method, thin AlN films
Vestnik KhNU ¹806 Pages. 99-102
For the first time the digital holographic interference microscope (DHIM) was used for investigation of thin films on transparent substrates. Three-dimensional images of AlN of thin films, deposited on acryl substrates by the vacuum-arc method have been obtained, their thicknesses have been measured. It has been shown that the DHIM can be successfully used for film surface quality checking, thickness and film damages parameters measurement.
3. Cathode static domen in transfer electron devise
Î. V. Botsula, D.V. Pavlenko, E.D. Prokhorov
static domen, Velocity – field characteristic, electric field strange
Vestnik KhNU ¹834 Pages. 104-107
The diode in which static cathode domen and under certain conditions impact ionization takes place has being considered. Transit time effect and noise oscillations takes place under impact ionization. The volatge to be lead to electric field strange abow 200 êÂ/sm (for gomogenues velosity – field characteristic in ower dides) have been derermened
4. Polarization and energy characteristics X-slots in the waveguide with the complex load and the dielectric inserts
Blinova N.K., Yatsuk N.N., Selyutin A.V.
Õ-slots , ellipse coefficient, VSWR level , circular polarization.
Vestnik KhNU ¹966 Pages. 77-81
The Õ-slots in a rectangular waveguide with the end complex loading and dielectric inhomogeneity at the waveguide input are considered. Calculation and experimental results of power and polarization descriptions are carried out for such systems. The possibilities of polarization and power characteristics of Õ-slot control are investigated. The variation of dielectric inhomogeneity and complex end loading parametors allows to obtain the circular polarization, high radiation coefficient and low VSWR level
earthquakes, VLF emissions, total electron content, equatorial anomaly
Vestnik KhNU ¹966 Pages. 103-110
Observational data about variations in VLF emissions and ionospheric total electron content near and at large distances from earthquake areas have been analyzed. The diurnal and day-to-day VLF variations have been shown to have features that correlate with variations in global seismic activity. The effects in the VLF variations occur both prior to enhancements in seismic activity (with the time lag proportional to the earthquake magnitude) and during first 24 h after the earthquake. The effect of violent earthquakes on latitudinal dependence of the total electron content may differ; specifically, the equatorial anomaly can disappear at distances of more than 6,000 km from the epicenter.
Wigner transform, Cohen’s transform class, space radio physics, signal processing, powerful non-stationary disturbance sources, Volcano explosion, solar eruption.
Vestnik KhNU ¹927 Pages. 89-95
Being a member of Cohen’s class of integral transforms, non-linear integral Wigner transform for analysis of the real signals and processes in geospace radar methods is applied. At samples of the May 18, 1980, explosion of Mount St. Hellens and the December 5, 2006, very strong X-ray solar eruption, the effectiveness of Wigner transform application to the processing of non-stationary, non-linear, fractal and ultrawideband signals and processes in problems of space radio physics, in particular, to the investigations of processes, accompanying the effects of powerful non-stationary disturbance sources was shown.
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