FORMATION OF THE RADIATION PATTERN OF PANEL ANTENNAS ON MASTS AND TOWERS

Abstract

The development of a national radio and television broadcasting network requires optimizing the coverage area for the frequency band used in various terrain conditions and density of the network receivers. This leads to solving the actual problem of designing broadcasting centers, whose antenna systems form radiation patterns with specified properties, such as attenuation zones in mountainous terrain or water area. For this purpose panel antennas mounted on masts and towers are often used. The purpose of the study. Consideration of rigorous electrodynamics formulations for mathematical models of panel antennas since the widely used concepts of infinite perfectly conductive screens do not consider the effects of mutual influence in an antenna system that consists of panel antennas and structural elements of masts and towers. Development of methods for designing optimal amplitude-phase distributions of antenna systems that meet the specified requirements for the radiation pattern. Materials and methods. A rigorous electrodynamics model of a panel antenna dipole is introduced as the Pocklyngton integral equation of the II kind. The complete mathematical model of a panel antenna is formulated as a system of integral equations. For the numerical solution the method of moments is used. Results. Estimates of the panel antenna radiation fields in the back area were obtained for various panel-reflector sizes. Changes in the antenna system radiation pattern caused by the influence of the structural elements of masts and towers were investigated. The use of optimization procedures for nonlinear problems of designing amplitude-phase distributions with reference to the geometry of the panel antenna layout leads to the possibility of forming a coverage area that is closest to the specified requirements for the selected criteria. Conclusion. The study results show the degree of compliance of the rigorous modeling results of panel antennas with approximate mirror image methods. The proposed mathematical model of the panel antenna can determine the frequency band of the antenna system input impedance for effective matching. Examples of modeling radiation patterns with a given coverage area for various objects are given.