Analytical and numerical techniques for the analysis of microstrip antennas

This paper deals with microstrip patch antennas of arbitrary shape, and techniques available for their analysis. It reviews the various approximate models utilized so far, and presents a rigorous mathematical approach, based on dyadic Green functions for stratified media. Integrals are obtained with integrands possessing both singularities and a divergent behavior at infinity: a numerical technique was set up for their integration. The antenna patch is cut up in rectangles, over which the surface currents are evaluated by a moment method. The antenna's input impedance is computed and compared with measured values.