Effect of substrate dielectric anisotropy on the frequency behavior of microstrip circuits

In this paper, we carry out a full-wave analysis of shielded two-port micro strip circuits, in which the metallizations are embedded in a multilayered substrate that may contain isotropic dielectrics and/or anisotropic dielect rics, The Galerkin's method in the spectral domain is applied for determini ng the current density on the metallizations of the circuits when their fee ding lines are excited by means of delta-gap generators, and the matrix pen cil technique is subsequently used for deembedding the scattering parameter s from the computed current densities, Results are presented for the scatte ring parameters of some microstrip discontinuities and tilters printed on b oth isotropic dielectric substrates and anisotropic dielectric substrates, These results show that when substrate dielectric anisotropy is ignored, er rors arise when computing the scattering parameters of microstrip discontin uities and when predicting the operating frequency band of microstrip filte rs.