A circuit approach to model narrow slot structures in a power bus

A coupled transmission line model for narrow slot structures in DC power planes is proposed. This approach, combined with SPICE-based cavity models and a segmentation method, provides an easy and fast way to model relatively complex structures of power planes with narrow slots often used for isolation purposes. This approach is used to achieve isolation using gapping. The cavity model formulations for rectangular and isosceles right triangular segments are reviewed. The rationale of modeling the narrow slot as a three-conductor transmission line is described. The modeling results are shown and compared with the output of a full wave simulation tool, HFSS, and with experimental measurements.