Dielectric waveguide approach for analysis on hybrid mode resonant frequency of a ring DR loaded cavity

An analytic field analysis method is applied to obtain the coupled expressions for calculating the hybrid mode (EH/sub 11/) resonant frequency of a ring dielectric resonator (DR) loaded cavity which is widely used for dual-mode elliptic response filters. The expressions newly derived in this paper are more general compared to those for a cylindrical DR loaded cavity. Since a dielectric waveguide approach has been adopted for analysis, the expressions in this paper can also be used for analyzing the hybrid mode of a dielectric loaded waveguide which has a hole at the center of the dielectric. With the aid of simple expressions, hybrid mode resonant frequency of a DR can be easily predicted without rigorous numerical methods.