Fast analysis of dual-reflectors quasi-optical system based on point matching method and Gaussian beam tracing

Gaussian beam tracing (GBT) is proven to be an effective ray tracing method in analyzing quasi-optical system with multi-reflector mirrors. The paper deals with its application in millimeter wave (MMW) band combining with the source pattern expansion using point matching method (PMM) and the beam tracing technique using geometrical optics (GO) method. Far-field pattern of TE10 mode is expanded into bundles of elementary Gaussian beams (GBs) based on the PMM, which is to get each emergent direction and coefficient. Radiation near-field and far-field pattern are obtained by introducing the astigmatic GBs to make a more quick performance evaluation about quasi-optical system, which are consecutively analyzed in dual-parabolic mirrors system based on the GO. Comparing near-field and far-field results with simulation values in the GRASP software is identical to the −50dB that reveals a good correctness of the algorithm design and system model.