ItemS-band planar strip array antennas without dielectric substrate(Видавництво Національного університету "Львівська політехніка", 2009) Martynyuk, S. Y.; Nazarenko, S. B.Novel designs of two S-band 4-elemnt (2×2) planar strip array antennas for wireless local area networks (WLAN) exploring the standard IEEE802.11b)g) are presented. The radiating elements of the proposed arrays are metal strip stacked patches, that allow to achieve frequency bandwidth more than 10%. The distinguishing feature of the designs is that strip arrays are air filled and completely free from using any dielectric substrates for holding the radiating patch elements. Manufactured prototypes of the arrays demonstrate good mechanical stability of proposed approach. Measured radiation patterns and frequency characteristic of VSWR are well agreed with theoretical models. ItemEnhanced 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. ItemControl of directional diagram of the inphase array for radiators of supershort radio impulses(Видавництво Національного університету "Львівська політехніка", 2009) Shostko, I. S.The method simultaneous excitation is considered of microwave oscillations in linear arrays of spark radiators. It is based on the voltage multiplication circuit’s usage. The influence is studied of the growing voltage along of antenna array and the switching time of dischargers in the array on performances of the directional diagram. The method of control directional diagram array is based on short-duration pulse shape properties. The beam direction depends on pulse radiators excitation parameters. The parameters experimental probing results are given for linear antenna array of spark radiators. ItemControl of the radiation characteristics of a leaky-wave antenna by manipulation of the grating profile(Видавництво Національного університету "Львівська політехніка", 2009) Steshenko, S. O.; Kirilenko, A. A.A leaky-wave antenna consisting of a lamellar grating of finite extent fed by a planar dielectric waveguide is considered. The mathematical model of the antenna is improved for calculating of the apertures with large size. The possibilities of the radiation characteristics control by choosing of grating profile with linear variation of the groove depths are investigated. ItemNew method of graphic representation of electromagnetic fields structure(Видавництво Національного університету "Львівська політехніка", 2009) Gribanov, A. N.A method of visual graphic representation of an electromagnetic field structure, which consists in rectangular grid mapping of data calculated in a polar coordinate system, is proposed herein. As a result of the Maxwell differential equation solution, a formula is determined which allows mapping force lines of electrical component of the field radiated by a linear array in any space domain. ItemResonance near-field microwave diagnostics in dermatology(Видавництво Національного університету "Львівська політехніка", 2009) Kostrov, A. V.; Strikovskiy, A. V.; Yanin, D. V.; Smirnov, A. I.; Pantileeva, G. A.; Davoyan, Z. V.Resonance sensors for noninvasive express diagnostics of biological tissues are developed. The sensor operation is based on the method of near-field microwave sounding. The state of a tissue is estimated by its electrodynamic parameters (dielectric permittivity and conductivity). The capabilities (sensitivity, resolution, etc.) of the measuring systems employed for investigation of skin and differential diagnostics of various dermatoses. ItemDirection of arrival estimation with sensor arrays(Видавництво Національного університету "Львівська політехніка", 2009) Czapska, J. M.; Yashchyshyn, Y.With recent increase of hardware capabilities, the application of sensor arrays in the Direction-Of-Arrival estimation is gaining more and more popularity. The behaviour of the array is the complex function of the geometry, sensor characteristic, signal and noise properties and other different factors. Before building the array it is essential to simulate its performance in different conditions with different algorithms. Most of the time the simulations are performed using custom ad-hoc created code. This code is error prone and difficult to maintain. Our goal was to create a reusable and extensible library that would provide the components used in the simulation process. In this paper we present the initial version of the library along with several illustrative examples. ItemAn 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. ItemThe 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. ItemIntegrated 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. ItemScattering properties of carbon nanotube antennas(Видавництво Національного університету "Львівська політехніка", 2009) Lerer, A. M.; Makhno, V. V.; Makhno, P. V.; Labunko, O. S.The boundary problem of diffraction and excitation of system of nanotubes-vibrators was reduced to solution of the integral equation (IE) with logarithmic kernel. After regularization the IEs were solved by means of collocation method considering th current’s behaviour at the vibrator's endings. The existence of resonances in the frequency range 0,1-1,0 THz was shown. ItemBlack body as an antenna and transmitter combination(Видавництво Національного університету "Львівська політехніка", 2009) Titov, A. N.In the presented report energy balance characteristics of the black body radiation is reviewed on the basis of the antenna technology concept. It shows that electromagnetic energy may be traced to energy performance of an equivalent link line. The report introduces such concepts as equivalent virtual transmitter power defined by the Black Body temperature and size, as well as the virtual antenna characterized with constant gain equal 4 and chaotic polarization. The presented review results in determination of passive radar range equations. ItemEstimation of positions of local narrow-band sources on a ship hull usinga vertical antenna array(Видавництво Національного університету "Львівська політехніка", 2009) Orlov, D. A.; Rodionov, A. A.; Turchin, V. I.A method for estimation of positions of local narrow-band sources on a moving ship, allowing one to identify the mechanisms making the greatest contribution to its sound pressure level, is proposed in the paper. The actuality of this problem is related to strengthening the requirements imposed on the sound pressure level of ships because of ecological and other requirements. The method is based on space-time filtering of the signal received by the elements of a vertical antenna array. The ship is supposed to move straightly and uniformly at a short distance from the array; the track parameters are supposed to be known. The results of the method testing with the use of the data obtained in sea experiment are presented in the paper. The testing has shown that the source localizing precision is close to the theoretically achievable one. An analysis of the method error is performed in a wide frequency range using numerical modeling. ItemThe 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. ItemNumerical 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. ItemThe broadband multichannel UHF transmitting TV antenna(Видавництво Національного університету "Львівська політехніка", 2009) Kudzin, V. P.; Sannikov, N. J.The broadband multichannel UHF transmitting TV antenna consisting of shunt dipoles is offered. The antenna works on several frequency channels simultaneously. The detailed numerical and experimental research is carried out and the geometry of the antenna is optimized. The structure of the antenna includes two orthogonal planes of radiators, the power divider and matching device. The industrial sample of the aerial is created. ItemDevelopment 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. ItemAntenna 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). ItemThe view of cable connection line as a form of antennas for assesment of its protectability from external noise during videoinformation transmission(Видавництво Національного університету "Львівська політехніка", 2009) Dudka, O. O.; Tsopa, O. I.; Shokalo, V. M.