Theory of bianisotropic cladded rectangular waveguide and directional coupler

In this study we extended the theory of isotropic rectangular waveguides to analyze the wave propagation in structures incorporating a rectangular isotropic core transversely enclosed in bianisotropic materials. The fruit of this work is the formulation of the characteristic equations for both E x and Ey cases. Our major achievement is our success in decoupling the TE and TM solutions.;Another important finding is the derivation of two separate characteristic equations for each Ex and Ey cases. It appears that the solution to each of these two equations approaches the propagation constant of the propagating waves of opposite directions.;We later extended the theory of isotropic directional coupler to the bianisotropic case considering structures which could be fabricated on bianisotropic substrates.