ZERO-CUTOFF MODE IN DIELECTRIC-LOADED COAXIAL WAVE GUIDE

摘要

Microwave ferrite isolators and phase shifters use partial dielectric loading to achieve the circular polarization essential to the operation of such devices. In this report an approximate solution is developed for the lowest propagating mode in coaxial waveguide partially filled with dielectric. The solution is obtained by assuming a value for 3, the propagation constant, and treating the problem as a perturbation of the zero-cutoff TEM mode which would generally exist in the guide were it filled homogeneously with dielectric. The points of maximum circular polarization are shown to lie on the dielectric interface roughly mid-way between the inner and outer conductors.