Dispersion Characteristics Analysis of Multilayer Microstrip Lines with Finite Ground Plane

A full-wave analysis of microstrip with a finite ground plane is developed using the Green´s functions of a multilayer geometry not backed by a ground plane. A two-dimensional Method of Moment (MoM) is used to derive the current distribution on each metallization including the finite ground plane. The calculated dispersion characteristics for coplanar strips are compared to the available experimental data where good a agreement is obtained. Then, the effect of the finite ground plane on the microstrip propagation characteristics is rigorously analysed. Finally, some experimental measurements of microstrip resonator with a limited ground plane are achieved and compared with the theoretical results.