Characterization of a Microstrip Line Referenced to a Meshed Return Plane Using 2-D Analysis

Transmission lines with meshed return planes offer enhanced flexibility but can introduce signal integrity challenges. Characterizing such transmission lines using full-wave simulation is accurate but time and resource intensive. In response, an efficient modeling method using 2-D analysis is proposed in this article. First, cross sections of the transmission line are taken at multiple locations to create a sampled representation of the changing geometry. The per-unit-length (PUL) RLGC parameters of each segment are obtained using 2-D analysis. The value of the inductance obtained from the 2-D analysis is then modified to account for the position-dependent current direction on the return plane. Finally, the segments are cascaded together to obtain the $S$ -parameters of the transmission line. The results obtained using this method closely align with those from 3-D full-wave simulations, demonstrating the effectiveness and efficiency of the proposed approach.