Plane wave spectra, test-zone fields and simulation of antenna-pattern measurements

Abstract

It is shown that a useful and vivid illustration of the effects of multipath in antenna ranges can be provided via the plane wave spectrum approach. Transforming from the plane wave spectrum to the test-zone field requires both a two-dimensional Fourier transform and a co-ordinate transform, and the test-zone field in the presence of multipath is then represented by a distorted sphere. Convolution can be used to predict the measured pattern, given the plane wave spectrum and the true pattern of the antenna. Alternatively, multiplication of the test-zone field and the true pattern will yield the same result.