Efficient Finite-Difference Description of 3D Edge Singularities for Coplanar MMICs Including Metalization Thickness

Incorporating the field singularities at metallic corners significantly improves efficiency of the finite-difference method without increasing numerical efforts. In the past, only the 2D case has been investigated. In this paper, we present a general approach to model both 2D and 3D edge singularities, particularly at sharp and re-entrant metallic corners and edges. The benefits are demonstrated for coplanar MMICs, where structure details such as finite metalization thickness play an important role. In order to treat arbitrary dielectrics accurate approximations of electric field singularity factors are given.