Elimination of false singularities in GTD equivalent edge currents

Abstract

The method of equivalent edge currents (MEC) has extended the applicability of GTD. The equivalent edge currents, however, generally suffer from false singularities outside the Keller cone. These singularities depend upon the co-ordinate for inner integration in the surface to edge integral reduction. The objective of this paper is to eliminate false singularities of the currents. A new co-ordinate for inner integration that maximises the phase variation of the integrand is proposed. Consistent use of this co-ordinate leads us to novel expressions for not only fringe but also PO and GTD equivalent edge currents without any false singularities. These currents are verified for diffraction from a disk and a square plate. It is numerically confirmed that GTD-MEC using new currents predicts uniform patterns and is almost comparable to PTD