A V-band miniaturized circularly polarized filtering feed horn for reflector antenna

In this paper, a miniaturized circularly polarized filter feed horn working in V-band is proposed. It consists of a third-order Chebyshev bandpass filter (BPF) with multi-layer gap waveguide (GW) structure and a circularly polarized horn antenna. Among them, the horn antenna is designed with an open slotted end structure, and the BPF is designed with a three-layer stacking structure based on GW to achieve circular polarization and miniaturization, respectively. The simulated results show that the filter feed horn has a working frequency of 59 - 64 GHz, a fractional bandwidth of 8.95 %, a gain of 10.5 ± 0.5 dBic, an axial ratio of less than 1 dB, which has a good electrical performance.