Polarization rotation properties of twisted uniaxial anisotropic medium

Abstract

In certain microwave applications, it is required to rotate the plane of polarization of a linearly polarized wave or beam by some desired angle relative to a fixed antenna or waveguide feed. Hence we study Polarization Rotation properties of one class of Polarization Rotators. Here we use twisted anisotropic medium to achieve desired rotation of the incident plane wave. We model a stack of uniaxial anisotropic layers, with their optic axis gradually rotated. A numerical study is made on this configuration for various structural parameters like thickness of each uniaxial layer, overall length of the structure, refractive indices, and angle of rotation. Prom our study, we arrive at an expression, which has to be satisfied by the overall length of the structure for effective polarization rotation. An approach to fabricate artificial uniaxial anisotropic medium is also presented.