Feed array synthesis for reflector antennas in contoured beam applications via an efficient and novel Gaussian beam technique

Abstract

A relatively rapid procedure is developed, which combines a novel Gaussian beam approach for the fast analysis of reflector antenna radiation patterns with an iterative optimization method, to synthesize feed array distributions for parabolic reflectors in contoured beam applications. Here, relatively few Gaussian beams are employed as electromagnetic basis functions to represent the field radiated by the feed array in a highly efficient manner. Closed form expressions are used to find the reflection and diffraction of each of these Gaussian beams when they are incident on the parabolic reflector after they are launched from appropriate locations on the feed array plane. The coefficients (or initial launching amplitudes) of the Gaussian beams used in this expansion for the radiation from the feed array are found via an efficient iterative optimization procedure based on the method of successive projections. These coefficients are then directly related to the strengths of the array element source distributions (or array weights). Numerical examples of practical interest are presented to illustrate the utility and the speed of the present approach, which is found to be substantially faster than conventional approaches for these cases.