基于紧耦合结构的宽带基站天线设计

随着5G移动通信频段的公布,传统基站天线已不足以覆盖其工作频段。文章以紧耦合阵列天线理论为基础,提出了一种基于紧耦合结构的交叉偶极子宽带基站天线。该天线由两对正交的领结状偶极子天线构成,通过两对交叉偶极子之间的耦合效应,有效地展宽了天线的阻抗带宽。同时,通过在天线和金属反射板之间加载电阻型频率选择表面,吸收由反射板引入的谐振反射波,改善天线高频端辐射性能。仿真及测试结果表明:该天线在1.7-3.6 GHz 频率范围内,可以满足基站天线的设计指标,两端口驻波比均小于1.5,两端口之间隔离度大于55 dB,半功率波束宽度满足65°±5°范围,且整个频段内增益均大于8.5 dBi。

Design of Broadband Base Station Antenna Based on Tightly Coupled Structure

With the announcement of the 5G mobile communication frequency band, the traditional base station antenna is insufficient to cover the frequency band. Based on the theory of tightly coupled array antennas, a cross-dipole wide-band base station antenna is proposed. The antenna is composed of a pair of orthogonal bowtie-shaped dipoles. The impedance bandwidth of the antenna is effectively broadened by the coupling effect between the adjacent dipoles. In addition, by loading a resistive frequency selective surface between the antenna and the metal reflector, the resonant reflected wave introduced by the reflector is absorbed, and the radiation performance at the high frequency end of the antenna is improved. The simulated and measured results show that the antenna can meet the design specifications of the base station antenna in the frequency range of 1.7-3.6 GHz. The two-port VSWR is less than 1.5. The isolation between the two ports is greater than 55 dB, and the half-power beam width satisfies the range from 60° to 70°. And the gain in the entire frequency band is greater than 8.5 dBi.