基于加载技术的高增益贴片天线的研究

High-gain patch antennas help to improve the communication distance and data rate, and thus will play an important role in future wireless communication systems. In view of the inherent low gain of conventional patch antennas, this project proposes a new technique of gain enhancement based on the shorting and slotting load. To reveal the basic working principle of high-gain radiation, different modes of patch antennas under the two loading schemes will be studied in terms of patch’s resonant size, field distribution, and current distribution. By properly combing qualitative analysis and quantitative calculation together, a general, effective and straightforward design method can be concluded. In this projects, the issues of low gain for fundamental mode and high side-lobes for higher-order modes will be addressed by introducing shorting and slotting load, respectively. Further, stable high gain in multiple and wide bands can be achieved by means of hybrid loading techniques. As compared with the traditional design methods, the high-gain techniques proposed in this project can significantly enhance the radiation gain of patch antennas with no need of increased antenna profile or extra radiators, showing the advantages of simple realization and excellent performance.

高增益贴片天线能提高通信距离和数据传输速率，在未来的无线通信系统中发挥着重要的作用。本项目针对传统贴片天线增益较低的问题，基于短路加载和缝隙加载技术，研究有效提高贴片天线辐射增益的设计方法。项目研究贴片天线不同模式在两种加载的扰动下其谐振尺寸、场分布和电流分布的变化规律，重点揭示其高增益辐射的基本机理，并将定性分析与定量计算有机结合，归纳出系统、高效而直接的设计方法。本项目利用短路加载和缝隙加载分别有效地解决贴片天线主模辐射增益过低和高次模辐射副瓣过高的问题，并进一步利用混合加载，在多频和宽频带内实现稳定的高增益特性。与传统的设计方法相比，本项目所提出的高增益技术，能在维持贴片天线剖面低且不依赖于其他辐射体的情况下，显著地提高贴片天线单元自身的辐射增益，具有结构简单和性能优越的特点。

针对贴片天线单元增益低、不适用于中远距离通信的问题，本项目提出了基于加载技术的高增益贴片天线设计方法，研究主要从几方面展开：1）利用短路加载提升贴片天线主模增益；2）利用缝隙加载重塑高次模的辐射方向图；3）结合多模技术和滤波天线技术，拓展了高增益天线的带宽；4）结合缝隙加载技术和高次模辐射特性，实现极化和方向图的可重构。仿真和实测结果表明，本项目所提出的高增益技术，能使单个贴片天线的增益提高至11-13dBi，高增益辐射条件下的带宽增加至10%以上，带内增益及波宽稳定性得到极大改善。该技术能在维持天线低剖面的前提下，有效增加了贴片天线的增益和带宽，解决了贴片天线应用的痛点问题，在移动终端、卫星通信、毫米波通信等领域有着重要的应用价值。