NEW BIORTHOGONALITY RELATIONS FOR INHOMOGENEOUS BIISOTROPIC PLANAR WAVE-GUIDES

Using a linear operator formalism this paper presents new biorthogonal ity relations for the hybrid modes supported by planar waveguides inho mogeneously filled with general biisotropic media. In the special case of lossless biisotropic media, the linear operator is self-adjoint, t he original and adjoint waveguides are identical and new orthogonality relations can be derived. As an example of application, the radiation modes of a grounded nonreciprocal and lossless biisotropic slab waveg uide are analyzed in terms of a pair of incident transverse electric ( ITE) and incident transverse magnetic (ITM) continuous modes, which ha ve the advantage of being mutually orthogonal and of having a clear ph ysical interpretation.