A wideband dual-polarized antenna with high-gain and low sidelobe level for 5G communication

In this paper, a wideband (3.29–3.83 GHz) dual-polarized microstrip antenna with stable high gain and low sidelobe level (SLL) is proposed. In the proposed structure, we introduce an air layer, four C-shaped parasitic patches, four pairs of shorting pins (SPs) and four C-shaped slots to improve the antenna's impedance matching, gain flatness, and SLL, simultaneously. More specifically, the air layer and parasitic patches are utilized to adjust the resonant frequency point and extend the antenna's bandwidth. Besides, the four pairs of SPs are employed to concentrate the antenna's surface current. This is beneficial for enhancing radiation directivity and making the proposed antenna have a stable high gain within the operating band. In addition, the four etched C-shaped slots are used to make the antenna have a uniform current distribution and suppress unwanted high-order radiation components, simultaneously. In most cases, the SLL can be reduced (lower than −5 dB) without distorting the main radiation pattern. For demonstration, a prototype is fabricated and measured. The measurement results show that the proposed antenna achieves a relative impedance bandwidth of 15.2% (from 3.29 to 3.83 GHz). Furthermore, the antenna gain varies approximately within 10.3±0.4 dBi over the frequency band of 3.3–3.8 GHz.