Analysis of microstrip lines coupled through an arbitrarily shaped aperture in a thick common ground plane

A flexible spectral domain analysis for characterizing aperture-coupled microstrip lines with a common ground plane of finite conductor thickness is presented. In this approach, the coupling aperture is allowed to have any size, shape, and thickness. The effects of surface wave and radiation are taken into account via the exact Green's function formulation in the spectral domain. Numerical results on the S-parameters generated using this method are presented for different aperture thicknesses and validated against published data for the zero thickness case.<>