Теорія та техніка антен (ICATT 2009). – 2009 р.

Permanent URI for this collectionhttps://ena.lpnu.ua/handle/ntb/3740

Матеріали 7-ої Міжнародної конференції

У книзі зібрано матеріали конференції, присвяченої проблемам у галузі розробки і впровадження антен.

Теорія та техніка антен = Antenna theory and techniques : матеріали 7-ої Міжнародної конференції, 9–12 червня 2009 року, Львів, Україна. – Львів : Видавництво Національного університету "Львівська політехніка", 2009. – 400 с. : іл.

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3-probe microwave measuring instrument of vibration of mechanical objects with non-plane surface 3-probe microwave measuring instrument of vibration of mechanical objects with non-plane surface
(Видавництво Національного університету "Львівська політехніка", 2009) Drobakhin, O. O.; Doronin, A. V.; Grigor’ev, V. V.
Application of processing, which is specific to holographic concept with three reference signals, for complex reflection coefficient measurements by means of three-probe waveguide section is suggested. A mathematical model of diode detector on base of neural net is considered. The model provides a high level of square-law of output signal of detector and complex reflection coefficient measurements. The optimal model of neural net has structure of 1-4-1 neurons. For measurement of movement parameters estimation was done. As object of researches there was a metal concave and convex surface with various curvatures. For a decrease of a noise influence in the data, the Tikhonov’s regularization method was used. Efficiency of the method has been proved experimentally.
A double-reflector antenna of millimeter range with wide-angle scanning
(Видавництво Національного університету "Львівська політехніка", 2009) Naumovich, N.; Muravjev, V.; Yurtsev, O.; Moskaliov, D.; Kizimenko, V.; Baty, C.
It is described the results of numerical simulation and experimental investigation of a double-reflector antenna. The antenna is made according to a certain scheme and it consists of a parabolic reflector (transreflector) horn feed, flat convergent mirror (twistreflector) and a dielectric radome. The transreflector is a thin parabolic radome which has a system of thin wires applied on it. It reflects the waves of linear polarization. The twistreflector turns the plane of polarization around 90.
A low phase noise microstrip push-push oscillator with third harmonic output
(Видавництво Національного університету "Львівська політехніка", 2009) Kotserzhynskyi, B. O.; Omelianenko, M. U.; Tsvelykh, I. S.
The results of the low noise microstrip oscillator design with 11 GHz output are presented in the paper. The oscillator is stabilized by the microstrip resonator and performed in the push-push circuit. In contrast to traditional even harmonics output, the third harmonic output is used, which is obtained by means of proposed 0-180° combiner unit at the oscillator‟s output. The use of third harmonic output signal made it possible to suppress even harmonics in the oscillator branches, which contributed to the phase noise reduction. Phase noise of the designed oscillator is measured to be no more than -92 dBc/Hz, -113 dBc/Hz, and -130 dBc/Hz at 10 kHz, 100 kHz, 1 MHz offsets from carrier, respectively.
A method of measurement of directivity characteristics of antenna’s elements for digital antenna array in conditions of jammers
(Видавництво Національного університету "Львівська політехніка", 2009) Slyusar, V. I.; Voloshko, S. V.
A new two-stage digital processing of OFDM signals for measurement of directivity characteristics (DC) of antenna elements in digital antenna array (DAA) with test sources is described in this report.
A new approach to analysis of curvilinear conducting surface radiators
(Видавництво Національного університету "Львівська політехніка", 2009) Dubrovka, F. F.; Tolkachov, O. V.
We present a new approach to analysis of curvilinear perfect conducting surface radiators. The feature of this approach is a formulation of boundary value problem as a system of integral equations in regard to the complex electrodynamic vector potential and the scalar potential and simultaneous solution of this system for unknown distributions of current density vector and charge density using technique of parametrical mapping for representing curvilinear surface and the Galerkin’s method with boundary elements. Advantages of the approach in comparison with the Harrington integral equation on example of surface current distributions at the third order surface (Ferguson’spatches) are demonstrated.
A novel broadband coaxial orthomode transducer with high port isolation
(Видавництво Національного університету "Львівська політехніка", 2009) Dubrovka, F. F.; Vasylenko, D. O.
A novel compact design of a broadband orthomode transducer with circular coaxial waveguide input and two orthogonal highly isolated rectangular waveguide outputs is presented. A neural-genetic algorithm is used to optimize the inner architecture of the OMT. Within the operational frequency band 3.4–4.2 GHz input return loss is less than –20 dB and isolation between ports is better than 30 dB. The TEM mode in coaxial structure is not excited due to the special design of the OMT.
Accuracy estimation of cross polar radiation prediction of open-ended thin-wall circular waveguide by Approximate methods
(Видавництво Національного університету "Львівська політехніка", 2009) Dubrovka, F. F.; Piltyay, S. I.
Approximate methods and exact factorization method have been used to predict peak crosspolar of radiation levels of open-ended thin-wall circular waveguides. The ranges of minimal discrepancy with factorization method are estimated for each approximate method. Optimal diameters that minimize peak crosspolar levels in front half-space, back half-space and the whole space have been defined.
Adaptive antenna systems of telecommunication networks
(Видавництво Національного університету "Львівська політехніка", 2009) Pelishok, V. O.
In modern wireless telecommunication networks are widely used adaptation to change, for example, communication channel parametres. Adaptive modulation, the coding and so on is thus used, that considerably improves efficiency of systems. Recently adaptation also is used in antenna systems. Substantial increase of efficiency of wireless networks as a whole is thus reached. "Intellectual" antennas (Smart-antennas) which can change the form of the directional pattern depending on concrete circumstances in a communication channel, and ways of increase of their efficiency are investigated.
Adaptive radiointerferometer with microprocessor of a signal in the mobile station of a troposphere communication
(Видавництво Національного університету "Львівська політехніка", 2009) Rudakov, V. I.
In the presentation is decides scientific problem of the application of adaptive radiointerferometer in the mobile station of a troposphere communication by modern realization of digital regimes for two-contours processing of troposphere signals, which is allow to increase signals stability and information reliability of the mobile station.
Adjustment and beam forming in circular antenna array with conformal and phase scanning
(Видавництво Національного університету "Львівська політехніка", 2009) Bobkov, Y.; Yurtsev, O.; Moiseev, A.; Moskalev, D.
The circular antenna array, composed of M linear antenna sub-arrays, is considered in this work. Every linear antenna sub-array includes N active modules. The signals from active antenna array modules in receive mode are processed in digital form. It is described the of the antenna phase adjustment, which is necessary for this type of antenna. It is also considered the influence of different factors to antenna radiation plot.
An effective approach to the fast, GPU-Based, Through-Wall imaging
(Видавництво Національного університету "Львівська політехніка", 2009) Capozzoli, A.; Curcio, C.; D’Elia, G.; Iadarola, G.; Liseno, A.; Vinetti, P.
We present an approach for the Through-Wall-Imaging based on a simple model of the scattering problem involving few unknowns, exploiting effectively the a priori information on the scenario and using a global optimization approach, relying on Legendre- Fenchel Transforms, tailored to fast, parallel implementations on Graphic Processing Units (GPUs). Experimental results are presented against X-band data collected in a realistic scenario made of a wall of Ytong concrete blocks and a metallic cylindrical scatterer.
An excitation of the linear antenna by the relativistic charge in the circular waveguide
(Видавництво Національного університету "Львівська політехніка", 2009) Prijmenko, S. D.; Rjabkova, E. P.
Excitation of a linear impedance antenna is considered in a unlimited circular waveguide. The antenna is located in the waveguide axis and is excited by the relativistic point charge scattered at the antenna end-wall. The electric current distribution and the charge linear density distribution along the antenna are calculated. The delta-shaped representation of a current on one of the antenna ends at the initial instant of time is given. The Green's function of an unlimited circular waveguide, and also the direct and inverse Fourier transform in time domain are used.
An optimized MAS for solving scattering problems
(Видавництво Національного університету "Львівська політехніка", 2009) Capozzoli, A.; Liseno, A.; Vinetti, P.; Curcio, C.; De Bono, G.; D’Elia, G.
A new criterion driving the choice of the locations of the Auxiliary Sourcers (AS) is introduced with the aim to improve the performance of the Method of Auxiliary Sources (MAS) applied to the solution of the integral equations as those encountered in electromagnetic scattering. The approach is based on the optimization of the singular value behavior of the matrix relating the AS excitations and the scattered field values at the matching points on the scatterer boundary. The ill-conditioning of the problem of determining the AS excitations matching the boundary conditions is then significantly reduced and the accuracy of the estimated scattered field is improved. The performance of the method is numerically assessed, in a 2D scalar geometry, by discussing in the details the case of a circular perfectly conducting scatterer.
Analysis and design of plasma monopole antenna
(Видавництво Національного університету "Львівська політехніка", 2009) Wei, Li; Jinghui, Qiu; Ying, Suo
Two kinds of plasma monopole antennas are simulated and analyzed in this paper. For different radius, reflection coefficient, radiation pattern and radiation efficiency of a cylindrical plasma monopole antenna are calculated respectively. According to actual situation, a conical plasma monopole antenna with different cone angle is simulated. Impedance and radiation characteristics of the plasma antenna are similar to the metal monopole antenna.
Analysis of fields reflected from model of human body surface using artificial neural network in time domain
(Видавництво Національного університету "Львівська політехніка", 2009) Shyrokorad, D. V.; Dumin, O. M.; Dumina, O. O.; Katrich, V. O.
The problem of determination of thickness a layer of layered medium by impulse irradiation is considered. The impulse fields reflected from the model of human body surface are analyzed by artificial neural network in time domain directly. The normal incidence of plane wave with Gaussian time form on the layered medium with losses is considered. The reflected electromagnetic field is obtained by FDTD method. Initial data for neural network analysis are the values of amplitude of electrical component of reflected field. As an example, the network is trained to determine the thickness of one of the layers of the medium. The stability of the determination in presence of interferences, experimental errors and instabilities of medium parameters is investigated by numerical simulation.
Antenna array development with non-linear signal processing
(Видавництво Національного університету "Львівська політехніка", 2009) Lobkova, L. M.; Lukjanchikov, A. V.
The method of build-up of antennas arrays with non-linear processing of received signals is offered, i.e. A correlation method which is applied not only to casual stationary processes, but also for the determined signals. Formulas for pattern diagram calculation are output.
Antenna synthesis based on the ant colony optimization algorithm
(Видавництво Національного університету "Львівська політехніка", 2009) Slyusar, V. I.; Ermolaev, S. Y.
This report are described the versions and the synthesis results of new designs of electrically small antenna based on ant colony optimization algorithms. To study the parameters of the frame and non-loopback vibrators MMANA package was used. Geometric forms that were obtained might be used as contour lines of printed, slot antenna or as forming surface of the crystal dielectric resonator antenna. A constructive meta-heuristic search algorithm for optimization of the antennas forms using solutions of travelling salesman problem (TSP).
Architectural solutions of testing network for mobile operators
(Видавництво Національного університету "Львівська політехніка", 2009) Kashtanov, I. V.; Arhelyuk, O. D.
The present paper aims at revealing of the main elements of the GSM network, the relationship between the subsystems of Telco-part and integrated IP-functional, such as billing-platform and additional services. The model of integration of VPN-functional in the operator testing network is proposed and the scheme of the signal exchange for incoming and outgoing calls involving VPN-platform is represented. Research is conducted on the basis of a real GSM-system. As practice shows, the test fragments in the network are an integral part of the functional network. Due to the test fragments it is possible completely to eliminate the risk factors in the integration of any equipment or functionality to the network operator, to reduce financial losses in migratory operations. With a help of the test network it became possible to provide «painless» to the core network training and professional development of specialists, who in future will operate the equipment, which is also one of the main expenditure items of telecommunication operator.
Array signal processing in long-range multimode channels: optimal schemes and effects of the signal coherence and modal noise
(Видавництво Національного університету "Львівська політехніка", 2009) Malekhanov, A. I.
It is well known that long-range signal propagation in random-inhomogeneous channels leads to loss of the signal coherence in space, time and frequency domains. As to large-array signal processing, an intrinsic issue arise if the array size is greater then a signal coherence length (for given distance and frequency band). Such a scenario is typical, for example, for long-range sound propagation in underwater channels. These channels are, in fact, multimode refraction-type waveguides, so the problem is to develop the largearray signal processing techniques under the conditions of coherence-reduced multimode signal against the noise background which contains a rather intensive modal component. In this paper, we consider the problem with emphasis on the optimal processing techniques resulted from the output signal-to-noise ratio criterion. Our focus is interrelated effects of the signal coherence loss and the modal noise (which partially or even completely interferes the modal signal) on the SNR array gain. We give also some results of computer simulation to compare the array processors in long-range underwater environments.
Asymptotic methods on the solution of diffraction problems on the convex impedance cylinders
(Видавництво Національного університету "Львівська політехніка", 2009) Vyunnik, V. I.; Zvyagintsev, A. A.
In work are considered problems of diffraction of electromagnetic waves by the impedance convex cylinder for two cases : the observation point and source point are located on removal from the cylinder and a source point is located in the close vicinity of the convex cilinder. Process of obtaining asymptotic interpolation formulas, suitable for calculations both in shadow and in lighted zones is described.