Generalized spectral analysis of planar lines on layered media including uniaxial and biaxial dielectric substrates

The spectral-domain analysis is generalized to compute the dispersive properties of a wide variety of planar and quasiplanar transmission lines (microstrips and finlines) printed on a stratified dielectric medium. Uniaxial and biaxial dielectric anisotropy can be easily manipulated due to the definition of a transverse propagation matrix characterizing each dielectric layer. The whole boundary value problem is reduced to two simpler problems involving only one or two dielectrics, and the spectral dyadic Green's function is derived by a recurrence algorithm. The dispersion equation is derived by using the Ritz-Galerkin method. The numerical convergence is substantially improved taking into account the asymptotic behavior of the series. A number of illustrative examples are included to emphasize the power of the method.>