Numerical comparison of exact and asymptotic methods for Sommerfeld integral evaluation with applications to microstrip antennas

In this paper a new method for evaluating Sommerfeld integrals for arbitrary source and receiver location pairs, for a horizontal electric dipole (HED) located at the air-dielectric interface of a PEC-terminated dielectric media, is described. The proposed method is valid for both large and small lateral separations, and for arbitrary receiver locations. Unlike past investigations, the proposed method avoids location, and associated residue calculation of the poles of the integrand through deforming a part of the real-axis in the upper half plane that is free from any pole singularities of the Sommerfeld integrand. Compared to an earlier investigation reported by the present authors, the present approach includes situations when both the source and receiver are exactly on the interface.