Design of Highly Selective Filtering Antenna Array

In this paper, a highly selective filtering antenna module based on LTCC process is designed to cascade a single-layer six-cavity dielectric filtering with a microstrip patch antenna array through a one-part-four T-shaped power divider, and a Ferro-A6M sheet with a thickness of 0.47 mm is used as the dielectric. A CQ topology is used to introduce cross-coupling, which generates transmission zeros at both ends of the passband and improves out-of-band rejection. The module as a whole achieves a return loss of less than -10.5 dB in the N257 band from 27 GHz to 29 GHz, a maximum antenna gain of 9.4 dBi at the center frequency, which is suitable for millimeter-wave communications because of its high selectivity and high out-of-band rejection.