Efficient Analytical Description of Metal Loss in Finite-Difference Waveguide Analysis

This paper treats the finite-difference (FD) analysis of planar transmission lines including metallic loss. From the quasi-static field behavior in the vicinity and inside of non-ideal metallic layers, analytical approximations are obtained and incorporated into the algorithm. Preprocessing can be automated. This approach leads to considerable savings in computational efforts, since the same mesh size as in the lossless case can be used and skin-depth does not need to be resolved. The benefits of the new method are demonstrated for two MMIC coplanar waveguides.