Application of MoL to shielded microstrip lines with bi-anisotropic biaxial substrates and cover layers

The method of lines (MoL) is applied to the analysis of shielded microstrip lines with bi-anisotropic biaxial substrates and superstrates (cover layers). Two coupled differential equations for the tangential electric field components, which govern the field behavior within anisotropic region, are derived using differential matrix operators. The MoL procedure is employed to discretize above equations along the transverse direction of the transmission line. Numerical results emphasize effects of strip-width, thickness of the substrate, and thickness of the superstrate on propagation characteristics of the line. In addition, the propagation constants of higher order modes are calculated for frequencies ranging from 1 to 35 GHz for substrates also exhibiting magnetic anisotropy. It is found that for this structure higher order modes tend to exist in clustered pairs