Analysis of polarization characteristics of cylindrical waveguide containing anisotropic dielectric using spatial network method

Abstract

AbstractRecently, various anisotropic materials have been used in the applications to the microwave and millimeter wave circuits. In such a structure, it is indispensable to analyze systematically the medium conditions, boundary conditions and resultant propagation characteristics of complicated electromagnetic fields. Of the electromagnetic characteristics associated with the anisotropic materials, the polarization characteristic is particularly important. Especially, the circular polarization recently has been used extensively as the fundamental propagation mode in satellite communication due to the stability of its propagation characteristics. The polarization characteristics are expected to be applied to the modulation/demodulation in the optical region and to the erasable optical disk memory.The present analysis considers the generating mechanism of these polarizations and carries out a numerical simulation of the fundamental mechanism by means of the spatial network method as applied to a structure made of an anisotropic dielectric disk or plate inserted in a circular waveguide. By taking advantage of the method, studies in the time domain are carried out so that the variations of the amplitude and phase of the electric field components at each spatial point are presented. From their mutual relationship, as the variation of the electric vector, the analysis determines the process in which the polarization plane characteristics are caused, including the rotation of the polarization plane from the linear polarization through elliptic polarizations and, finally, to the circular polarization depending on the rotation of the principal axis of the anisotropy.