A new formulation of the boundary condition at infinity for a hybrid radiation mode and its application to the analysis of radiation modes of microstrip lines

A new formulation of the boundary condition at infinity for a hybrid radiation model is introduced. It is shown that its application leads to an iterative solution of the problem in the spectral domain. The validity of the condition is proved by its application to the analysis of a laterally shielded dielectric slab. Using this condition, an iterative method in the spectral domain is proposed in order to analyze striplike stratified transmission lines. As a result, two solutions, classified as perturbed longitudinal electric (LSE) and longitudinal section magnetic (LSM) modes, are obtained. Numerical results concerning the convergence of the method as well as the field distribution are presented for the case of a microstrip line.<
>