Iteration Path-Length Error Correction Approach to Subreflector Shaping for Distortion Compensation of Large Reflector Antenna

TL;DR: In this article, a method performing an iterative approximation to the geometrical optics and physical optics analysis is proposed to shape a subreflector for antenna distortion compensation, which is very suitable for a large reflector antenna with a small-amplitude deformation and smoothly varying errors.

Abstract: At the stage of structural optimization, the subreflector structure should be designed such that it compensates for the residual error or relaxes the accuracy requirement of the main reflector to a certain extent. However, there is no fast and effective means to shape the subreflector during the structural optimization process. This communication is based on the application of geometrical optics (GO)/physical optics (PO) analysis to shape a subreflector for antenna distortion compensation. Thus, a method performing an iterative approximation to the GO/PO analysis is proposed. Unlike GO shaping or optimization, the proposed method is not formulated by simultaneous nonlinear ordinary differential equations. Therefore, the main contribution of this communication is that the method does not entail computationally intensive calculation and optimization, and thus, it does not require a large amount of time to complete the calculation. The proposed method is very suitable for a large reflector antenna with a small-amplitude deformation and smoothly varying errors such that the shaped subreflector does not have a significant effect on the amplitude of the main reflector’s electric field. An example with regard to the symmetric system is presented. The obtained results demonstrate that the proposed method is effective.