Begell House Inc.
Telecommunications and Radio Engineering
TRE
0040-2508
73
19
2014
ON HISTORY OF OCCURRENCE OF STATISTICAL ANTENNA THEORY (SAT). PECULIARITIES OF SAT COMPARED TO USUAL ANTENNA THEORY
1689-1711
10.1615/TelecomRadEng.v73.i19.10
Ya. S.
Shifrin
Kharkov National University of Radio Engineering and Electronics, Ukraine
Statistical antenna theory
side radiation level
superdirectivity
Factors that stimulated creation of the statistical antenna theory at the beginning of the sixties of the last century, peculiarities of the theory, new concepts and new effects inherent in it are discussed.
ON THE CHOICE OF OPTIMAL TOPOLOGY OF A REFLECTING MODULE BASED UPON THE CIRCULAR-DISK MICROSTRIP STRUCTURE
1713-1726
10.1615/TelecomRadEng.v73.i19.20
D. V.
Mayboroda
V. Karazin National University of Kharkiv, 4 Svobody Sq., Kharkiv 61022, Ukraine
Sergey A.
Pogarsky
V. Karazin National University of Kharkiv, 4 Svobody Sq., Kharkiv 61022, Ukraine
Circular disk-microstrip resonator
slitting
resonant-frequency spectrum
directional pattern
In this paper the constructions of reflecting modules developed around circular-disk-microstrip resonators is discussed. Parametric simulation has been performed in terms of a complex approach using the integral equations and the finite-element method. The impact of segmenting the circular disks with the aid slits upon the key characteristics of the structure in question has been studied.
SIGNAL AND FLUCTUATION CHARACTERISTICS OF AUTODYNE VIBRATION AND DISPLACEMENT METERS
1727-1743
10.1615/TelecomRadEng.v73.i19.30
V. Ya.
Noskov
Ural Federal University (UrFU), 19, Mira St., Ekaterinburg, 620002, Russia
G. P.
Ermak
O.Ya. Usikov Institute for Radio Physics and Electronics, National Academy of Sciences of Ukraine, 12, Academician Proskura St., Kharkiv 61085, Ukraine
Autodyne vibration meter
autodyne
signal characteristics
noise characteristics
The research data and experimental results of particularities of formation of signal and noise characteristics of autodyne vibration and displacement meters functioning under the conditions of strong external feedback are provided for various operation points and methods for autodyne signal registration. The experimental results are obtained using the Tigel-08M hybrid integral module manufactured on the basis of 8-mm planar Gunn diode.
SPECTRA AND WAVEFORMS OF ELF PULSES IN THE EARTH-IONOSPHERE CAVITY HAVING THE SMALL LOSSES
1745-1762
10.1615/TelecomRadEng.v73.i19.40
A. P.
Nickolaenko
O.Ya. Usikov Institute for Radio Physics and Electronics,
National Academy of Sciences of Ukraine
12, Academician Proskura St., Kharkiv 61085, Ukraine
Schumann resonance
exponential conductivity profile
spectra and pulsed waveforms in the cavity with negligible losses
There is kind of gap in the literature on the Schumann resonance. The prediction of the phenomenon was made for the Earth-ionosphere cavity with perfectly conducting walls. However, in the modeling of experimentally observed resonance, the ionosphere has a finite conductivity, while the Earth is always considered as a perfectly conducting sphere. The present investigation fills in the blank mentioned. We demonstrate for the first time the spectra and the waveforms of pulsed radio waves propagating in the cavity with negligible losses. The problem is solved in the framework of the exponential vertical profile of the air conductivity characterized by the single scale height. The spectra and waveforms are computed at a set of the source-observer distances. Deviations are demonstrated in the spectra of the idealistic resonator from the real Earth-ionosphere cavity. Pulses in the time domain were computed showing alterations in the propagation velocity caused by the finite conductivity of the ionosphere. The pulse amplitudes were computed at the source antipode and at the source point itself for the round-the-world wave. We demonstrate the gradual widening of the pulses in the course of propagation combined with the reduction of their amplitude. Amplitude of the round-the-world wave reduces to the extent excluding the "auto-triggering" of lightning strokes even in the idealistic cavity model of negligible losses.
IRREDUNDANT CONFIGURATIONS OF ELEMENTS IN LARGE-APERTURE SQUARE AND HEXAGONAL ARRAYS
1763-1770
10.1615/TelecomRadEng.v73.i19.50
L. E.
Kopilovich
A. Usikov Institute of Radio Physics and Electronics, National Academy of Sciences of Ukraine, 12, Academician Proskura St., Kharkov 61085, Ukraine
Interferometers
irredundant configurations
planar difference sets
square arrays
hexagonal arrays
High-resolution images in radio and optical astronomy are obtained with the use of interferometers which elements form an irredundant configuration. With a given number of elements, interferometers of the kind are capable of measuring the maximum number of spatial frequencies and also make it possible to use methods which allow eliminating phase fluctuations produced by the medium inhomogeneity. The process of developing a mathematical model of an interferometer of the kind with a 2D aperture requires a great many of computations which sharply increases with the number of elements when it is necessary to enlarge the aperture size. The conventional statistical methods prove to be insufficiently efficient in this case. The present paper suggests a regular technique for constructing mathematical models of 2D apertures representing integral arrays with an irredundant configuration of the elements. The method is based on the use of the special combinatorial structures which are planar difference sets. The properties of these sets are briefly described and the practice of their use for solving the assigned problems is described. In the paper, the irredundant configurations with the maximized number of elements in the square and hexagonal arrays, as well as those providing the complete coverage of the central part of the spatial frequency range are constructed. The maximum permissible number of the elements of the irredundant configuration is estimated for the arrays of these kinds. The suggested method makes it possible to construct irredundant configurations with the maximized number of elements in the 2D large-aperture arrays. The technique can be used for solving optimization problems in the course of designing interferometer systems intended for astronomical research. The approach is more efficient as compared with the statistical ones with respect to the amount of calculations and the necessary computation time.
ON THE POSSIBILITY OF THE ATMOSPHERE CONDITION DIAGNOSTICS WITH THE MULTIBEAM INTERFEROMETER
1771-1779
10.1615/TelecomRadEng.v73.i19.60
Y. V.
Kornienko
O.Ya. Usikov Institute for Radio Physics and Electronics, National Academy of Sciences of Ukraine, 12 Academician Proskura St., Kharkiv 61085, Ukraine
V.V.
Pugach
A.Ya. Usikov Institute for Radiophysics and Electronics
Sergey I.
Skuratovskiy
O.Ya. Usikov Institute for Radio Physics and Electronics, National Academy of Sciences of Ukraine, 12 Academician Proskura St., Kharkiv 61085, Ukraine
Astronomic observations
phase distortions
multibeam interferometer
atmosphere condition diagnostics
adaptive optics
The influence of the atmosphere on the results of astronomic observations from the Earth surface dramatically decreases the resolution of obtained images. Many methods of fight against it require the information on atmospheric distortions. Obtaining of such information in practical case is usually carried out by using special wavefront sensors that operate on the basis of the natural or laser reference star. But there is the method that allows obtaining information on phase distortions in the atmosphere directly during the process of the observation of any object with the multibeam interferometer. Averaged over subapertures phases are the side result of image forming with such instrument. By their interpolation the phase distortions distribution over the aperture may be recovered. It was shown that the reconstruction accuracy is acceptable while atmospheric inhomogeneities exceed the distance between subapertures. The dependences of reconstruction accuracy on peculiar inhomogeneities size and mean square deviation of phase distortions are presented. The research results may be useful for atmospheric researches, as well as for fight against its influence, for example, first order adaptive correction.