Fields in anisotropic hard surface waveguide with application to polarisation transformer

Electromagnetic fields inside a circular axially corrugated waveguide, also called a hard surface waveguide, are considered. The waveguide is filled with uniaxial anisotropic material. The eigenfields in this kind of waveguide are TE and TM fields which propagate with different propagation factors. Polarisation properties of reflected and transmitted fields are studied. This kind of waveguide component can be used for changing handedness, as a polarisation transformer, and a mode filter element for hard surface waveguides. As a practical example, the polarisation transforming effect of a sapphire filled hard surface waveguide is considered