Spectral domain analysis of square spiral microstrip antennas

Abstract

A square spiral placed on a dielectric slab which is backed by a ground plane is analyzed. The spectral domain Green's functions for a current element on a grounded dielectric slab are used to develop an integral equation which is solved by the method of moments. In this formulation, the effects of the dielectric material are rigorously modeled. The current density on one arm of the square microstrip spiral at 6.0 GHz is shown as a function of subdomain number and compares favorably to the results found in H. Nakano et al. (1986) for the Archimedean spiral. The gain, axial ratio, and input impedance of the square microstrip spiral are shown as functions of frequency and also compare favorably to the results for the Archimedean spiral.<>