Efficient evaluation of near-field PO scattering from PEC objects illuminated by arbitrary far-field sources

Antennas radiation on electrically large objects is often encountered in computational electromagnetics. In this paper, we present an approximation strategy for the line integral reduction of arbitrary far-field source excitation. By approximating the arbitrary far-field source as different vector point sources for each sub-segment on the contour of the PO integral surface, the PO scattered field is cast in a line integral format. This algorithm permits a fast and accurate evaluation of the PO integral for arbitrary far-field source excitation. Compared with traditional line integral approach by expressing the incident wave as angular spectrum of plane waves, our method is simpler and more explicit. Numerical examples are presented to illustrate the exactness of the line integral representation.