A Dual-Mode Dual-Channel Dielectric Waveguide Filter

In this paper, a dual-mode dual-channel filter using dielectric waveguide resonators (DWRs) is proposed. Compared with the filter based on dielectric-loaded metal cavity resonator, the volume can be greatly reduced. Meanwhile, the DWR still has high unloaded quality factor. The orthogonal modes (TM210 and TM120) provide a good isolation for the two channels. The resonant frequencies of these two modes can be selected independently by changing the lengths of the two sides of the rectangular DWR. The two filters share the same DWR in the first order and cascade their own resonators in the second order along the directions of orthogonal modes. The adjustment of the external quality factor and coupling coefficient of one channel does not affect the corresponding parameters of the other channel. That is, the two integrated filters are mutually independent of each other. The simulated results show that the proposed dualchannel filter has the advantages of low insertion loss, compact size and good selectivity.