Design of K-Band SIW H-Plane Horn Antenna with Filtering Response

In this paper, a K-band SIW filtering horn antenna is proposed. Cross-coupling of the resonant modes occurs in the filtering structure, which can introduce two radiation nulls to achieve frequency selectivity. The phase correction structure modifies the phase distribution of the radiation field to improve the radiation gain. The gradual transition structure acts as the impedance converter, which can improve the impedance matching and the front-to-back ratio. The antenna gain at the two radiation nulls (19.8/26.6 GHz) drops below -25 dB, which has good frequency selectivity. In addition, the antenna has the advantages of low profile, high realized gain (9.15 dBi), and the 10-dB relative bandwidth reaches about 10%. The filtering structure and phase correction structure would not increase the size of the antenna, and the design could meet the requirements of miniaturization and integration.