Design of a Filtering Antenna with High Stopband Suppression for Ku-band Satellite Communications

In this paper, a six-slits filtering antenna with high stopband suppression is designed for Ku-band satellite communications. In order to acquire a waveguide transmission line with good filtering characteristic, a set of stepped metal rods are introduced into the rectangular waveguide. The proposed antenna has a 10 dB impedance bandwidth from 11.79 GHz to 13.05 GHz, covering the downlink frequency band (from 12.25 to 12.75 GHz) of Ku-band SATCOM. It also has a stable gain around 15 dBi within downlink band. Meanwhile, this antenna obtains a high outband rejection more than 26.5 dB in uplink band (14 ~ 14.5 GHz) and can be expanded to a planar array easily.