A robust closed-form green’s function technique for method of moments analysis of microstrip antennas embedded in cylindrically stratified media

In this paper, an efficient technique has been proposed to improve the convergence of the summations involved in the Green´s functions for cylindrically stratified media as an improvement to the previous work. The major contribution of this paper is to employ asymptotic forms of generalized reflection matrices to improve the convergence of these summations. Unlike the numerical procedure proposed earlier, these asymptotic forms are obtained analytically by using large order approximations for Bessel and Hankel function rather than numerical extrapolation. The proposed technique is expected to be efficient in computing the spatial domain Green´s functions.