ALGORITHM FOR GENERATING AN EXTENDED DIRECTIVITY PATTERN OF A PHASED ARRAY ANTENNA

Abstract

An analysis of existing methods for synthesizing antennas according to a given radiation pattern, in which the generated radiation pattern is the sum of partial rays, is carried out. It has been established that in these methods an iterative process is organized, at each step of which a new additional beam is added to the already formed beam. In this case, search optimization algorithms are used to determine the parameters of the additional beam. The existence of these methods allows us to separately consider algorithms for determining the parameters of additional rays at each step of the iterative process, as processes for solving independent problems. A variation of such a problem is the search for parameters of additional rays to form a one-dimensionally extended radiation pattern. An analytical algorithm for the formation of a one-dimensionally expanded beam of a linear antenna is proposed and justified, represented as a sum of three narrower partial beams after determining two unknown parameters: the angle of separation of additional beams and the complex amplitude of these beams. Relationships have been obtained that make it possible to reduce the problem of forming an extended beam of a linear antenna to the problem of optimizing the expression for one parameter - the angle of separation of additional beams relative to the central one. It is shown that the second required parameter, the complex amplitude of the additional beam, is determined analytically. It was established that the choice of the required parameters of the optimization problem should be based on the requirements for maximizing the directional coefficient. After solving the optimization problem, the amplitude-phase distribution in the aperture of a linear antenna is represented as a superposition of three amplitude-phase distributions to form the corresponding partial rays. It is shown that the algorithm has limitations associated with the expansion of rays, since the feasibility of the requirements is related to the width of the used partial rays. In this regard, it is indicated that the proposed algorithm should be considered as an integral part of an iterative process, at each step of which additional beam expansion occurs. The results of the implementation of the proposed algorithm when forming several extended beams are presented, which confirm the performance of the proposed algorithm.