Wideband and Low-Profile Filtering Antenna Based on Metasurface and CRSS

In this article, we introduce a filtering antenna with broadband and a compact design. It leverages metasurface (MTS) technology in conjunction with the complementary split ring resonator (CSRR) topology. The antenna consists of three parts, including the feeding line, the aperture layer, and the MTS layer. The MTS is excited by a coupled aperture cut out of the ground plane. Besides, the CSRR is loaded on the ground plane to utilize the resonant characteristic and obtain a low-frequency radiation null. Furthermore, the MTS is made up of non-uniform rectangle units and a rectangle ring slot is etched in the outer elements. Due to the non-uniformity of the MTS and the rectangle ring slot, the excited current of the MTS at high frequency is neutralized and two high-frequency radiation nulls are obtained. Hence, the filtering function of the antenna is achieved. In the simulation, the antenna shows a wide -10-dB impedance bandwidth of 40.8% and a good out-of-band radiation suppression level of more than 15 dB. Meanwhile, the antenna has a low prolife of 0.06 λ (at the center operating frequency) and a peak gain of 8 dBi.