A Wideband SIW Filtering Antenna with Multiple Radiation Nulls

This paper presents a broadband filtering antenna based on substrate integrated waveguide (SIW) technology. The antenna consists of an SIW resonant cavity, a circular patch, and a complementary split-ring resonator (CSRR) on the ground. The antenna is fed diagonally and two slits are opened on the top layer to generate perturbation effects, splitting the cavity radiation mode. Two slots are opened on the patch to split the patch radiation mode. The combined radiation of the cavity and patch achieves a wider impedance bandwidth. Opening a complementary resonant split ring on the ground further expands the bandwidth. Simulation results indicate that the antenna has a wideband and good filtering effect.