Design of a Broadband Base Station Antenna Based on Tightly Coupled Structure

In this paper, a dual-polarized cross-dipoles base station antenna based on tightly coupled structure is proposed. The coupling effect between the orthogonal dipoles effectively broadens the impedance bandwidth of the antenna. Meanwhile, a resistive frequency selective surface is added between the antenna radiator and the metal reflector to absorb the resonant reflection wave, resulting in better radiation performance at high frequency. The simulation results show that the antenna can meet the 2G/3G/4G base station antenna criteria, and can operate in the 5G frequency band (3.4 GHz to 3.6GHz). The VSWR of both ports are lower than 1.5, and the isolation between two ports is greater than 49 dB. The half-power beam width varies from 60° to 70°, and the gain across band is greater than 8.5 dBi.