Simulation of slow wave mode propagation using the finite element method

A finite element simulation has been implemented to evaluate the slow wave mode propagation characteristics in metal-insulator-semiconductor waveguiding structures. Particular emphasis has been placed on coplanar waveguides compatible with silicon integrated circuit, with an objective of evaluating the effect of inhomogeneous doping on propagation characteristics. The simulator has been benchmarked successfully against a number of cases presented in the literature (usually within five to ten %), including MIS coplanar waveguides. The effect of inhomogeneos doping and finite metallization in maintaining a large slowing factor while reducing the attenuation constant and increasing transmission line Q is presented, and constraints on slow wave mode passive components are discussed.