一种提高微带MIMO 天线端口隔离度的新方法

多输入多输出(MIMO) 无线通信系统已经成为提高通信系统可靠性和数据传输速率的有效技术。MIMO 通信系统中,终端天线的性能对系统通信容量的提升至关重要。为了提高天线端口隔离度,提出了一种在微带天线辐射贴片上加载缝隙阵列实现天线极化分集,提高天线隔离度的方法,并且将这种方法应用于两个2 单元微带MIMO 天线设计中,取得了良好的效果。缝隙阵列加载不但抑制了微带MIMO 天线单元间的耦合,而且产生了更多谐振频点,改善了高频谐振频点畸变的天线辐射方向图,并且天线尺寸也得到了很大的减缩。最后对比分析了设计的两个微带MIMO 天线,实测结果与仿真计算比较可知,在工作带宽内,单元天线间耦合得到了非常有效的抑制。这种在平面天线辐射贴片加载缝隙阵列改变天线极化方向的技术可以很好地用来抑制多天线系统中单元天线间的耦合,而且对天线的其他性能不会造成影响。

A Novel Method of Slot-Array Loading to Enhance Port Isolation of the Microstrip MIMO Antenna

Multiple input and multiple output (MIMO) systems have become an effective technique to enhance the capacity and improve reliability of the wireless communication system without additional transmitted power and spectrum, and MIMO system greatly depends on the quality of the MIMO antenna. This paper proposes a novel effective method of slot-array loading on the metal radiator of microstrip MIMO antenna to improve the port isolation between the antenna elements. The slot-array loading is capable to transform the polarization of the microstrip antenna, and two kinds of microstrip MIMO antenna are designed to verify the validity of method aforementioned. Furthermore, the loading brings about more resonance frequencies, modifies the distorted radiation pattern at the higher order mode and miniaturizes the microstrip MIMO antenna.Dual kinds of the microstrip slot-array loaded MIMO antennas have been simulated by HFSS 15. 0, fabricated and tested by the Agilent PNA Series Network Analyzer E8363B. The simulated results and the tested results are greatly agreed to each other, and the slot-array loaded MIMO antennas were also compared with the reference identical unloaded MIMO antennas to confirm the method proposed in this paper. The slot-array loading on the radiator of the microstrip antenna is an effective approach to transform the polarization, improve the port isolation between the microstrip MIMO antenna elements and hardly impact the other characteristics of the antenna.