CAD model extraction of PCB signal discontinuity using a circuit extraction approach based on mixed-potential integral equation formulation

In high-speed digital design, signal via transitions on printed circuit boards (PCBs) are becoming an important signal integrity issue. Efficient and accurate models for via transitions are necessary to analyze high bit-rate digital circuit system. The circuit extraction approach based on a mixed-potential integral equation formulation (CEMPIE) is an extension of the Partial Element Equivalent Circuit approach (PEEC) to general multi-layered media. CEMPIE was further developed to include the horizontal current components on the vertical surface and extended to model the discontinuities on multilayer PCBs. A procedure of building SPICE models for signal via transitions between printed circuit board layers was developed. The method of extracting SPICE model parameters from full-wave simulation tool was studied. The validity of SPICE models was studied by comparing solutions from SPICE models with solutions from full-wave simulations. This procedure was further used for building SPICE models for via transitions in differential signaling.