A NOVEL COUPLING METHOD FOR DUAL-MODE DIELECTRIC RESONATORS AND WAVE-GUIDE FILTERS

A new method for coupling dual-mode waveguide or dielectric resonator cavities is described and analyzed. The method has the advantages of providing a practical, flexible, economic means of replacing irises, of offering easy tunability of the coupling over a wide range of coupling values, and of reducing the length of the coupling structure. Calculation of the resonator's coupling parameters using the mode-matching method yields accurate results and is verified by measurements. Experimental four-pole dual-mode elliptic function filters using the new coupling method for empty cavities and dielectric-resonator-loaded cavities were constructed and tested. The test results showed excellent agreement with theoretical analysis.