Rigorous Design of Truncated Cylindrical Cavity for Dual Mode Dielectric Resonator Filters Applying the Finite Element Method

A novel dielectric resonator filter with truncated cylindrical cavity is proposed in order to realize dual mode narrow band filters without tuning and coupling elements. A full electromagnetic optimization method using the three dimensional finite element method permits rigorous prediction of a two pole filter. A representative prototype of dual mode dielectric resonator filter using truncated metallic cavity is built and tested. The favorable comparison between experimental and theoretical results validates our coupling technique and the accuracy of our computations. At last, the design of an elliptic four pole dual mode DR filter with truncated cavities and original tuning iris is proposed.