Efficient implementation of discrete complex images method in spatial domain moment method to analyze microstrip transmission lines

Planar guiding structures are analyzed using a mixed-potential integral-equation (MPIE) formulation solved by the method of moments (MoM). Closed-form two-dimensional Green's functions for the scalar and vector potentials are analytically obtained in the space domain due to the approximation of its spectral domain version with discrete complex images method (DCIM), thus avoiding lengthy numerical evaluations. It will be shown that a suitable choice of the sampling path is key to reducing the number of images and to avoid the necessity of extracting spectral poles. The advantages of this approach will be illustrated by numerical results.