Asymmetric coupled transmission lines with anisotropic coupling

The characteristics of asymmetric coupled transmission lines are derived for the case of general anisotropic coupling, special cases of which are certain geometries of anisotropic materials or from distributed active devices. In addition to deriving the terminal characteristics for the uniform coupled-line, four-port case with anisotropic coupling, it is shown that simplified alternate equivalent expressions for the mode impedances and admittances can be derived. These simplified expressions are useful when examining special cases where a good approximation can be achieved by considering either a generalized anisotropic mutual admittance.<>