Modeling Local Via Structures Using Innovative PEEC Formulation Based on Cavity Green´s Functions With Wave Port Excitation

Complex via structures such as noncircular antipads are rigorously studied, in the local region close to vias, using an innovative partial-element equivalent-circuit (PEEC) formulation based on the cavity Green´s functions. The problem under study is an essential building block that can be used to model complex multilayer structures. With the usage of the cavity Green´s functions, the number of unknowns is significantly reduced. Further, nonorthogonal quadrilateral mesh is used to better accommodate the complex shape of the antipads in practical designs. A novel wave port excitation method is proposed, which is new for the PEEC formulations. Singularity extraction in self element calculations involving the nonorthogonal cell and the cavity Green´s functions is studied. The impedance parameters of several via structures are obtained using the proposed method, and the results are validated with the finite-element solution from a commercial tool.