Alternative formulation of the electric field in a stratified medium applied with a mixed spectral-spatial coupling calculation for integral equation modelling of vertical current sheets

Integral equation modelling of electromagnetic radiation and interference phenomena in planar circuits and antennas offers exact solutions usually at the cost of excessive computation time, especially when arbitrary 3D conducting surfaces are involved. However, for most of these problems, the geometry can be restricted to the 2.5D case, that is, only horizontal (parallel to layer structure) and vertical conducting surfaces (normal to the dielectric layers) are present. This paper reports progress in the full wave analysis of these structures. An alternative but generally valid form for the electric field in the stratified medium is presented. For the 2.5D geometry, but modelling all current components, the availability of analytical expressions for the Green's functions in the spectral domain is then exploited to perform a mixed spectral and spatial calculation of the matrix elements required to solve the integral equation. An overall reduction of computation time is hereby envisaged. Numerical results of actual 2.5D structures are provided.