Dual-channel filter based on dielectric resonator for 5G massive MIMO system

摘要

In this paper, we present a method for designing dual-channel bandpass filters (BPFs) using dielectric resonator (DR). Two BPFs are integrated as one dual-channel filter with two input ports and two output ports. By using a common quad-mode DR shared by two second-order BPFs, only one metallic cavity is needed, which greatly reduces the circuit size. By properly arranging the input and output feeding probes, two of the resonant modes are excited for one channel and other two for the other channel. Since the feeding probes of one channel filter do not excite the resonant modes of the other one, isolation between two filters is achieved. Three transmission zeros are generated near the passband, resulting in high selectivity and good out-of-band rejection. For verification, the dual-channel filter is implemented, which features good bandpass responses and offers a significant size reduction in comparison with conventional two DR filters.