Acceleration on the synthesis of shaped reflector antennas for contoured beam applications via Gaussian beam approach

Abstract

Shaped reflector antennas have been widely employed in the application of contoured beam configurations. According to the predefined requirements, the reflector surfaces are continuously synthesized in an iterative procedure until an optimized shape is reached. However, the repeated computation of the scattering from the reflector surfaces in every iteration conventionally using numerical integration of physical optics (PO) approximation or aperture integration (AI) technique usually makes iterative procedures very inefficient for the synthesis of large reflectors. Recently an asymptotic Gaussian beam (GB) technique was developed and has been successfully employed for the fast analysis of various shaped reflector antennas. This GB technique completely avoids the numerical integration, and thus makes the analysis very efficient. In this paper, the GB technique was incorporated into an iterative optimization algorithm based on steepest decent method (SDM) to arrive at an optimum configuration of the reflector surface which produces the desired contoured beam when it is illuminated by a feed source. Numerical results shows that this GB approach has tremendously accelerated the synthesis procedure by an order of magnitude in comparison with the conventional PO approach.