Two-Path Cutoff Waveguide Dielectric Resonator Filters

We propose here a new idea to design filters for achieving new levels of performance. This type of filters is made of a rectangular waveguide with a partial H-plane bifurcation. Each bifurcated section finite in length operates as a cutoff waveguide, at the central part of which low permittivity dielectric resonators are loaded. An accurate CAD program is developed which is based on a procedure that takes into account the effect of not only the dominant, but also a large number of higher order modes generated at discontinuities . Experiments for X-band trial filters designed by a new program show good agreements with the theory.