Compact dual‐polarized filtering antenna with enhanced bandwidth for 5G sub‐6 GHz applications

Abstract

A broadband dual-polarized filtering antenna with a compact size and high skirt selectivity for fifth-generation (5G) sub-6 GHz applications is proposed in this paper. The antenna is composed of two feeding networks and four shorted patches, which is based on a slot-aperture excitation scheme. By employing the novel defected ground LC resonator structures (DGLCRSs) and two different types of open-ended structures, the proposed dual-polarized antenna realizes satisfactory filtering performance as well as an improved operating bandwidth simultaneously. During which, four radiation nulls are generated at the both band edges and can be individually controlled. To further enhance the upper stopband performance, four pairs of meander-shaped slots are inserted on the patches symmetrically, which introduces another controllable radiation null. The working mechanism for achieving the filtering responses is provided. A fabricated prototype and experimental results demonstrate that an impedance bandwidth of 42.9% (3.3–5.1 GHz) is first obtained in a low-profile dual-polarization structure, covering the entire 5G N77/N78/N79 bands. The measured gain is about 8.1 dBi within the passband, while the stopband suppression is better than 16 dB up to 1.85 fc. These merits make the proposed antenna quite potential for the 5G new radio communication systems.