PWS Scattering computation

Recently, due to the ability of a computer to perform two-dimensional (2D) Fourier transformations via the Fast Fourier Transformation (FFT) algorithm and its capability to perform numerical integrations, Plane Wave Spectrum (PWS) Scattering techniques have become practical. The PWS scattering analysis represents a radiating source by a twodimensional spectrum of plane waves and characterizes a scatterer by its PWS scattering matrix. The scattered field is then obtained by calculating the integral of the inner product of the incident PWS and the scattering matrix. This calculation is, in effect, a 2D integration performed over the set of incident plane waves. It is the objective of this article to demonstrate that this analysis is, in fact, simple and straightforward. Several examples will be presented wherein simple scattering models, such as Physical Optics, have been used to describe the PWS scattering matrix and thus calculate the scattered field with good results. Also, the technique is both straightforward and powerful for the analysis of antenna coupling in the presence of obstacles. These examples demonstrate that the PWS Scattering Matrix method is a practical and cost effective approach to the analysis of many near-field scattering problems.