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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Mathematical models of the radiating and waveguide structures with N-fold periodicity
(Видавництво Національного університету "Львівська політехніка", 2009) Hoblyk, V. V.
In present article the results of development of the mathematical models of the wide class of radiating and waveguiding structures of divisible periodicity of constructive parameters are represented.
The electromagnetic waves diffraction by bounded and semi-infinite sequences of plane screens with slot
(Видавництво Національного університету "Львівська політехніка", 2009) Kaliberda, M. E.; Pogarsky, S. A.; Phenichnaya, S. V.
The diffraction problem of electromagnetic waves by the systems of plane screens with slot was considered. The operator approach was used. The possibility of eigenwaves propagation between screens was took into consideration. The dependencies of reflection and transmission coefficients of structure and excitation coefficient of plane waveguides from the distance between screens were investigated.
EM analysis of planar electronically scanned array antennas with radiating element errors
(Видавництво Національного університету "Львівська політехніка", 2009) Wang, C. S.; Liu, M.; Ping, L. H.; Bao, H.
The analysis of electromagnetic performances of active electronically scanned array antennas (AESA) with distorted plane errors is important to the engineering development of high-performance antennas. An coupled influencing model is developed, which describes the effect on the performances of the errors caused by the bent and bowl shape distortion in the plane element positions. The application of the model to a plane array antenna demonstrates the degradation of the sidelobe level and gain of the antenna with different distortion grades. The satisfactory analysis results provide a theoretical guidance for the engineer to determine the structural tolerance.
Modelling of street radio links as Microwave Multiports at work of system WIMAX in the conditions of the city
(Видавництво Національного університету "Львівська політехніка", 2009) Strelnitskiy, A. A.; Tsopa, A. I.; Shokalo, V. M.
The approached method of calculation of attenuation of radio-waves along street wave channels with the help canyon radio waves propagation (RWP) models and the Microwave Office packet of applied programs has been developed. The comparative analysis of the results of calculation and experiment for a case of WiMAX system operating in the central area of Kharkiv has been supplied.
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.
Influence of interference in GSM network and optimum solutions
(Видавництво Національного університету "Львівська політехніка", 2009) Kashtanov, I. V.; Arhelyuk, O. D.
The frequency band used in GSM network is mostly overload. For required network access traffic surface the channels inside the network are repeatedly used. It increases the negative interference processes. As a result the quality of service and the network capacity become lower. The effective optimisation methods decreases the interference influence and guarantees the comfort signal to noise ratio.
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.
Integrated antenna synthesis of the objects monitoring systems in the microwave band
(Видавництво Національного університету "Львівська політехніка", 2009) Prudyus, I. N.; Zubkov, A. M; Zakharia, Y. A.; Mymrikov, D. O.
The paper presents the principle of the integrated antenna synthesis of the objects monitoring systems in the microwave band. The main attention is paid to the selection of allocation and geometrical sizes of feed horns for providing identical beamwidth in mutually perpendicular planes.
Numerical analysis of patch antenna as antenna array element
(Видавництво Національного університету "Львівська політехніка", 2009) Kizimenko, V.; Bobkov, Y.
The patch antennas as antenna array element can be modeling by finite element method (programs Microwave Office, Ansoft HFSS and other). But this method need to use fast computer with memory large size. In this work the authors make an attempt to use thin wire integral equation method for patch antenna analysis. The results of modeling by proposed method are compared with the same of modeling by finite elements method and experimental results.
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.
Metamaterials on antenna solutions
(Видавництво Національного університету "Львівська політехніка", 2009) Slyusar, V. I.
This report describes the theory of metamaterials and its utilization for antenna's techniques. Metamaterials exhibit qualitatively new electromagnetic response functions that can not be found in the nature. The present report reviews basic historical aspects of the meta-environments theory development. Also the role of Veselago, the well-know theorist of negative refraction index metastructures whose 80 anniversary is celebrated in present year is emphasized as well as the role of other scientists.
The linear polarized horn antenna with decreased effective scattering area
(Видавництво Національного університету "Львівська політехніка", 2009) Manoilov, V. P.; Pavluk, V. V.; Sidorchuk, O. L.; Karashchuk, N. N.
The linear polarized rectangular horn antenna with decreased effective scattering area construction is offered. The method of the horn antenna excitation by the longitudinal slot is proposed. Reduction of the effective scattering area is achieved by absorption of the higher wave modes excited by a falling wave.
Thin vibrators with arbitrary excitation and surface impedance
(Видавництво Національного університету "Львівська політехніка", 2009) Nesterenko, M. V.; Katrich, V. A.; Dakhov, V. M.; Berdnik, S. L.
The approximate analytical solution of the integral equation concerning the current in a thin straight vibrator with variable complex surface impedance has been obtained. The vibrator is located in unlimited space and is excited by the arbitrary field of impressed sources. For the case of vibrator’s excitation in the distinct from the centre point along its length the calculations have been carried out and the plots of electrodynamic characteristics of the vibrator, depending on the magnitude and the type of its surface impedance and location of the point of excitation, are presented.
The research of antennas on the cold plasma
(Видавництво Національного університету "Львівська політехніка", 2009) Ovsyanikov, V. V.; Jakimenko, S. V.; Moroz, S. M.
The results of researches internal and external characteristics of loop and rod antennas on the basis of cold plasma gas discharge are presented. The rows of advantages of such antennas above the metallic ones have been pointed.
Development of the radiating part of an ultra-wideband tapered-slot antenna for GPR applications
(Видавництво Національного університету "Львівська політехніка", 2009) Maksimovitch, Ye.; Mikhnev, V.; Vainikainen, P.
This paper presents some techniques of improving characteristics of planar ultrawideband antennas based on the tapered slot line. Different antenna openings based on the elliptical taper with additional metal flares, smooth and corrugated bent blades had been studied. Several planar antennas with dimensions of 23 to 12 centimeters have been simulated using electromagnetic simulation software, and then designed, fabricated and tested. Results of computer simulations and measurements of the ultra-wideband antenna characteristics are presented.
Research of multiantenna systems of telecommunication networks
(Видавництво Національного університету "Львівська політехніка", 2009) Klimash, M. M.; Pelishok, V. O.; Yaremko, O. M.
In the given work different types of multiantenna systems are investigated: with several aerials on transferring or on the reception party, and also on both parties simultaneously (MIMO, Multiple Input Multiple Output). Different kinds of processing of signals, as on transferring (STBC, Space-Time Block Coding) and on reciving to the party (BLAST, Bell Laboratories Layered Space-Time) are considered. Influence of multiantenna systems on the basic indicators of wireless neetworks (probability of occurrence of bit errors, speed of transfer data) is investigated.
The new method of electronic scanning
(Видавництво Національного університету "Львівська політехніка", 2009) Khludneva, A.; Mikhailov, M.; Paslyon, V.
We investigate the possibility of using the reversing mediums in the antenna engineering that gives us the ability to improve characteristics of the antenna systems; particularly we can receive the adjusted form and width of the directional diagram in the microwave range and we can also command the directional diagram while scanning within the adjusted rule.
Computational methods in mathematical and computer modeling of electromagnetic field distribution behind the grate of scatterers
(Видавництво Національного університету "Львівська політехніка", 2009) Otdielnov, V. A.
The paper is devoted to the modeling of electromagnetic field distribution behind the grating of scatterers. The electromagnetic directivity diagram is simulated by hardware. The mathematical and technical design of electromagnetic field distribution in presence of one and a few scatterers, also as with regulations changes of the last ones is realized. The results can be used and allowed for antenna industries, radio station elements and other radio technical facilities manufacturing.
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.
Enhanced transmission through below-cutoff holes and eigenoscillations of waveguide objects and periodical structures
(Видавництво Національного університету "Львівська політехніка", 2009) Kirilenko, Anatoliy A.; Kolmakova (Don), Nataliya G.; Perov, Andrey O.
The spectral theory is used to explain the enhanced transmission phenomenon. Eigenoscillations of corresponding waveguide and periodic open resonators have been studied. Their influence on frequency response is demonstrated for various structures. It has been found that the origin of this recently discovered effect is in the existence of the eigenoscillations of the interface between the free half-space and the metal half-space perforated with double-periodic set of channels or the eigenoscillations of the waveguide plane junction.