Broadband Filtering Antenna Based on Microstrip Patch and Substrate Integrated Waveguide

A filtering antenna based on microstrip patch and substrate integrated waveguide (SIW) is proposed in this paper. The proposed antenna is mainly composed of three resonators including two half-mode patch resonators and one SIW cavity. To be specific, the rectangular SIW cavity is embedded in the half-mode rectangular patch resonator and the half-mode circular patch resonator is in the rectangular SIW cavity. The wide bandwidth is realized by using the dominant mode of each resonator. In addition, high-selectivity filtering response is achieved with two radiation nulls at both sides of the passband The simulated results indicate that the proposed antenna operates at the center frequency of 3.39 GHz with the fractional bandwidth of 19.15%. Besides, the realized gain within the passband is up to 7.19 dBi. Two radiation nulls locate at 2.73 GHz and 3.83 GHz respectively.