兼具同频和异频去耦功能的下一代WLAN可重构MIMO天线研究

The channel capacity can be enhanced by using more element antennas in next-generation WLAN MIMO system. With the increase of the element antennas in limited space, the in-band and out-of-band coupling between different elements will become stronger. There will be higher requirement for the miniaturization of reconfigurable element antenna. To solve these problems, the applicant will conduct innovative research on next-generation WLAN reconfigurable MIMO antenna with in-band and out-of-band decoupling functions in this project. The detailed research contents include: 1) Achieve out-of-band decoupling utilizing the out-of-band suppression function of filtering antennas without any additional decoupling structures. 2) Achieve in-band decoupling in dual wide frequency bands based on dual-band metamaterial structures. 3) Integrate reconfigurability and filtering function into a single antenna which can have dynamic reconfigurability and out-of-band decoupling functions simultaneously to simply the system structure. 4) Complete the design of dense dual-band reconfigurable MIMO antenna with in-band and out-of-band decoupling functions based on the aforementioned key techniques. This project aims to make breakthroughs at the research fields of reconfigurability, decoupling, and miniaturization for the MIMO antenna with dense distribution of elements. The applicant has published 3 pieces of papers in the top journal TAP, and the total number of his SCI and EI papers has reached 18.

下一代WLAN MIMO系统拟布局更多天线进一步提升系统容量。随着有限空间内天线数量增多，相同和不同频率的天线单元之间会分别面临更严重的同频和异频耦合问题，对可重构天线单元小型化要求更高。针对这些问题，本项目创新性地开展兼具同频和异频去耦功能的下一代WLAN可重构MIMO天线研究。具体内容包括：①利用滤波天线单元的带外抑制功能，在无需去耦结构的情况下实现异频去耦；②基于双频超材料在两个较宽频带内同时实现同频去耦；③融合可重构和滤波技术到单个天线，使其兼具辐射特性动态切换和异频去耦功能，以简化系统结构；④在上述关键技术基础上实现兼具同频和异频去耦功能的密集双频可重构MIMO天线。本项目预期突破MIMO天线密集分布情况下所面临的可重构、去耦、小型化等关键问题。申请人在与本项目相关领域发表TAP论文3篇， SCI、EI论文总数18篇。

随着移动通信系统天线单元数量的增多，在有限空间内，天线单元之间会产生很强的同频或异频耦合，影响天线的辐射性能。利用滤波天线的带外抑制功能可减小异频耦合。此外，方向图或极化可重构天线可以根据信道条件的变化动态地改变辐射特性，有效提升系统容量。. 基于上述考虑，本项目开展了兼具同频和异频去耦功能的下一代可重构MIMO天线研究。本项目在规划的滤波天线、可重构天线、天线阵列等方向取得了一定的成果。. 天线单元方面，通过充分激励天线辐射体和巴伦的自身内在的固有谐振模式提出了无需任何外加滤波结构的双极化滤波天线，该天线可以覆盖1.7-2.8 GHz频段，带外抑制在20 dB以上。基于人工磁导体和全波长缝隙结构实现了宽带波束可重构天线，该天线可以在4.9-5.5 GHz频段内实现从0°到±36°的波束切换。基于人工磁导体表面和缝隙单元辐射相消效应提出了宽带锥形波束天线，在4.83-6.25 GHz宽带范围内实现了水平方向全向覆盖，并具有低SAR值。. 天线阵列方面，提出了一种基于嵌入式滤波单元的双频双极化天线阵列，兼容790-862 MHz和880-960 MHz两个频段，利用天线单元的滤波特性减小了高低频单元的异频耦合；提出了一种±45°双极化全向辐射天线，三个紧密交叉的偶极子均匀排列成规则的三角形，并由两个“1分3”的等幅同相的功分器激励，该阵列可实现52.3％的宽阻抗带宽；完成了一种紧凑型高隔离双频双极化5G大规模天线阵列，兼容3.4-3.6 GHz和4.8-5 GHz频段，双频段内波束扫描范围可以覆盖±60°，增益达到17 dBi以上，效率在70%以上。. 本项目共计发表SCI/EI论文7篇，其中本领域顶刊IEEE Trans. AP论文4篇，中国工程院院刊综述论文1篇。申请中国发明专利12项，授权实用新型专利4项。