Creating directional beams from numerical data

A numerical technique is introduced which allows one to start from moment method type information and compute electric currents that produces a narrow beam of radiation in a given direction. This technique generalizes from the geometrical theory of diffraction (GTD), which is based on solving canonical problems, to a general method applicable to arbitrary surfaces. The difficulty in moment method calculations is in the manipulation of a large impedance matrix containing the effect of different sources on different testing functions. This paper describes a method for localizing physical effects to allow more efficient calculations.