Modeling of a Microstrip Line Referenced to a Meshed Return Plane

Transmission lines referenced to meshed return planes are widely used because of the physical flexibility imparted by the meshed plane. Poor accounting for the meshed ground, however, can lead to severe signal integrity and radio frequency interference issues. Full-wave simulation can characterize the electrical performance at an early design stage, but it is both time and computational resource consuming. To make the simulation more efficient, a method is proposed in this study to model transmission lines with a meshed reference ground using 2D analysis. The 2D analysis is performed at several locations along the length of the trace above the meshed return to determine per-unit-length RLGC parameters and partial self - and mutual-inductances of the trace and meshed return. The partial self-inductance of the return is then corrected to account for the current direction along the mesh. Cascading the corrected S-parameters for each segment is then used to estimate the overall characteristics of the transmission line. Results found using this approach closely match those found with 3D full-wave simulation.