移动端MIMO多天线阵列高次模去耦技术研究

MIMO technology has been considered as an indispensable revolutionary technology for 5G system due to its unique advantage of multiplying the channel capacity for wireless communication system. However, in practical 5G MIMO system, MIMO mobile platform only has limited free space for multi-antenna elements, which makes the antennas close to each other and brings strong coupling between antennas. This problem greatly deteriorates the performance of 5G MIMO system. Therefore, a suitable method should be developed to increase the isolation between multi-antenna elements (more than two units). Hence, the applicant plans to conduct a research project on the decoupling method of multi-antenna array based on high-order mode analysis for mobile MIMO platform. The research of our new antenna decoupling method will mainly focus on the ways to decouple complex antenna elements and to increase the number of decoupled antenna elements. The research content is as follows. First, the applicant will study the excitation source characteristic of complex antenna elements and utilize the high-order mode decoupling method to optimize the isolation between two complex antennas. Second, the applicant will take simple basic antenna elements as research objects and explore the way to decouple more antenna elements using the high-order mode decoupling method. Furthermore, based on the effort of the previous two tasks, the applicant will probe the means of applying the high-order mode decoupling method among multi-complex antenna elements in mobile MIMO platform. Finally, an experimental platform is built to test the fabricated prototype antenna. The experimental data is analyzed to validate the decoupling method proposed in this project. Consequently, this project will achieve the theory and technology innovations for the multi-antenna decoupling method. The achievement will provide necessary theoretical and technical support for the design of multi-antenna array on 5G mobile MIMO platform.

MIMO技术能成倍提高无线通信系统的信道容量，被认为是5G不可或缺的革命性技术。然而，移动端有限空间内布置多副天线将导致天线间产生强烈耦合，严重影响MIMO技术优势发挥。如何优化5G移动端MIMO多天线阵列中各单元间隔离度，亟待解决。为此，本项目围绕最新的移动端MIMO多天线阵列高次模去耦技术开展研究，针对该技术在复杂天线单元去耦和多天线单元（两单元以上）去耦方面遇到的困难与挑战，拟开展如下研究：1）研究复杂天线单元激励源特性，在此基础上利用高次模去耦法实现两个复杂天线单元间隔离度优化；2）以简单的基本天线单元为研究对象，探索提升高次模去耦方法适用天线单元数量的途径；3）进一步开展多个复杂天线单元间高次模去耦方法研究；4）搭建实验平台，完成天线加工与测试，分析数据，评估结果。最终本项目将实现MIMO移动端多天线去耦理论和技术的创新，为5G移动端MIMO多天线阵列设计提供必要的理论和技术支撑

本研究以5G移动终端MIMO多天线阵列的去耦技术为出发点，着眼于研究多单元阵列和复杂电磁环境中的天线耦合机理和应用。多输入多输出(Multiple-Input Multiple- Output：MIMO) 技术利用多个发射天线和接收天线实现数据的并行传输，已经成为5G核心技术之一。但在实际5G系统中，MIMO移动端中各天线单元间距离进一步减小，极易产生强烈耦合，严重影响MIMO天线的总体性能，因此需要采用合适去耦方法优化5G移动端MIMO多天线阵列中各天线单元间的隔离度。本研究过程中，负责人集中探索基于高次模去耦技术的移动端高隔离度MIMO多天线阵列的相关理论，并在此基础上设计高隔离度MIMO移动端天线。其核心思想是利用金属地板上电磁场（处于高次模式）的稳定极小值点来实现天线单元隔离度优化，此方法降低移动端的复杂度和成本，同时该方法也是CMA去耦理论在5G移动终端MIMO多天线去耦方面的发展和补充。此后，负责人进一步研究天线之间的激励和耦合机理，探索基于模式分析的MIMO多天线阵列去耦技术，并将研究范围逐步扩展到复杂强电磁耦合环境中的天线耦合机理和应用，取得具有代表性的成果包括但不限于如下：（1）基于贴片电容解耦的5G移动端小型化紧布置MIMO天线研究（2）5G移动终端MIMO芯片集成模块天线研究（3）双端口芯片集成TM10模式MIMO天线研究（4）双频自解耦的MIMO天线对研究（5）基于高次模解耦的三端口MIMO天线研究（6）紧耦合阵列天线单元研究（7）强耦合条件下宽带高增益隐身Fabry-Perot谐振天线研究。