针对WlAn的MIMO系统应用要求,并缩小天线所占据的空间,设计具有高端口隔离度的双极化贴片天线。采用共面带状线馈电的环形贴片和微带馈电单极贴片相结合形式,利用环形辐射元与单极子辐射元产生正交线极化的特点,实现双馈双极化天线。实验结果显示,所设计天线的工作频带范围为2.27~2.73gHz,端口隔离度在31db以上。同时,单极结构辐射元主极化要比其交叉极化大25db以上,环形结构辐射元在较大空间范围内其主极化比交叉极化大23db以上。这表明所设计双馈双极化天线具有较高的端口隔离度,且有良好的极化纯度。通过结构参数调整,还可望同时覆盖5.8gHz频段,以满足IEEE802.11n标准要求。A dual-polarized patch antenna with high port isolation is designed to reduce the antenna space in MIMO systems for WLAN.A ring patch of coplanar stripline port and a monopole patch of mirostrip feed line are co-located constructing the dual-port antenna,where the ring radiator and monopole patch can excite the orthogonally linear polarization radiation patterns.The experimental results show that the operating frequency range of the prototype antenna is from 2.27 to2.73GHz and the port isolation is larger than 31dB over the working band.For the monopole radiator the co-polarization electric field level is 25dB larger than the cross-polarization while for the ring radiator this value is larger than 23dB over the working spatial angle.So it can be concluded that the designed antenna has the characteristics of high port isolation and acceptable polarization.By adjusting the structure parameters,it is possible for this antenna to cover the 5.8GHz frequency band as the protocol IEEE802.11n requirement.厦门市科技计划项目(3502Z20123012); 高校博士学科点专项科研基金(20120121120027
