Study of PO analytic methods for serrated CATR quiet zone simulation

A detailed study of several analytic methods for the simulation of a compact antenna test range (CATR) quiet zone field is presented. The focus of the present paper is to develop a fast simulation model suited for an optimization process of the CATR geometry in order to minimize the desired quiet zone parameters, such as amplitude taper and ripple, phase variation and crosspolar level, for a wide range of frequencies. The algorithms introduced are based on Physical Optics (PO) that provides accurate results at high frequencies, when the reflector size is very large in wavelengths. Unlike conventional PO algorithms, where the surface current integration is performed with a finite integral, here the problem is addressed by modeling the reflector surface as a set of equivalent radiating planar triangles. Comparisons between the developed method and the direct integration approach are given to justify the computational savings. A Fast Physical Optics algorithm is implemented for evaluating the quiet zone field to further reduce computational times.