Hankel transform domain analysis of an annular-ring microstrip antenna with an air gap

An accurate and efficient method is presented for computing the resonant frequencies of an annular-ring microstrip antenna with an air gap. The formulation of the problem is carried out rigorously using the full wave analysis. The method of analysis is based on Galerkin´s method applied in the Hankel transform domain. The calculated results for the resonant frequencies are presented as a function of the width of the air gap and some are compared with the measured results available in the literature. Excellent agreement between theory and experiment is obtained, and the validity of the present method is confirmed