A Low-Profile Broadband Dual-Polarized Antenna with Coupled Feed Structure and AMC for 5G Base Station Application

In this article, a low-profile broadband dual-polarized antenna with a bilateral coupled feed and artificial magnetic conductor(AMC) is proposed. The antenna is composed of a radiating patch at the top, parasitic strips around it, a coupling feed structure under the radiating patch, a balun, an AMC structure and a slotted reflector at the bottom. The operating frequency band of the antenna is 0.69 ~ 0.96 GHz, and the overall size is small with low profile characteristics. It is 260 mm x260mm x 34.5 mm (approximately <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$0.718\lambda_{0}\times 0.718\lambda_{0}\times 0.096\lambda_{0}), S_{11}$</tex> and <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$S_{22}$</tex> are below -10 dB in the operating band, and the isolation between the two ports is lower than -24 dB. At the same time, it has a stable realization gain (8.16±1.01 dBi) and maintains excellent cross-polarization discrimination (XPD). Finally, the antenna's front-to-back ratio (FTBR) is higher than 22 dB, which has low backward radiation characteristics. The half-power beamwidth (HPBW) in the XOZ plane is (67.34°±6.13°), which meets the performance requirements for 5G base station antenna covering low frequency band.