基于耦合机理的宽带定向圆极化微带天线研究

Radio systems are moving towards multifunction, and the trend increases the number of loaded information subsystems. As a widely used device for signal reception and emission, the directional circularly polarized microstrip antenna must achieve larger bandwidth. Unfortunately, the existing antenna theory and technology cannot meet the demand and severely hinder the development of radio systems. Multi-feed technology increases the bandwidth of the circularly polarized antenna, and attracts considerable attention in recent years. The project prepares to investigate the wideband directional circularly polarized microstrip antenna based on the electromagnetic coupling mechanisms. First of all, the configuration and theory of the wideband 180° phase shifter will be explored and the four-feed network for power division and phase shift will be designed by adopting coupled line. Secondly, the structure and basic theory of the wideband low-profile hybrid coupling feed structure that combines inductive unit and capacitive unit will be investigated by using the principle of wideband multistage impedance matching. Thirdly, the bandwidth expanding theory and design method of the circularly polarized radiating structure will be researched based on the mutual coupling effect of the multi-patch. At last, the theoretical and applied research of the four-feed wideband directional circularly polarized microstrip antenna will be carried out. The project aims at providing theoretical foundation and technical guidance to the design of wideband directional circularly polarized antenna in multifunction radio systems, and decreases the complexity, cost, and size of the radio-frequency front-end. Therefore, the research results of the project not only have important theoretical significance, but also possess extensive application prospect and great economic benefit.

无线电子系统正朝着多功能射频系统方向发展，使其需要搭载的信息子系统不断增加；定向圆极化微带天线作为广泛使用的信号收发装置就必须具有更大带宽，而目前的天线理论和技术难以满足这一需求，成为制约无线系统发展的“瓶颈”。近年来，圆极化天线多馈点带宽扩展技术倍受关注。本项目拟基于耦合机理开展宽带定向圆极化微带天线研究；首先，采用耦合线及理论进行宽带180°移相器结构和理论探索、以及四馈点功分移相馈电网络设计；然后，利用宽带多级阻抗匹配原理开展宽带低剖面电感和电容混合型耦合馈电结构探索和基础理论研究；其次，基于多贴片耦合效应开展圆极化辐射结构带宽扩展理论和设计方法研究；最后，开展四馈点宽带定向圆极化微带天线理论和应用研究。项目旨在为多功能无线系统中宽带定向圆极化天线设计提供理论基础和技术指导，显著减小射频前端复杂度、成本和体积，研究结果不仅具有重要理论意义，而且具有广泛的应用前景和很好的经济效益。

定向圆极化微带天线作为新型多功能无线通信系统中广泛使用的信号收发装置，必须具有更大带宽以满足应用需求。本项目基于耦合机理开展了定向圆极化微带天线带宽扩展研究；首先，开展了宽带移相器和四馈电功分移相馈电网络技术研究；然后，探索出宽带耦合馈电结构和宽带多贴片弱耦合圆极化辐射结构；最后，开展了紧凑型宽带定向圆极化微带天线应用研究，设计并制作了天线样机。根据仿真和测试结果可知，天线的阻抗带宽大于98%，轴比带宽大于96%，3-dB增益带宽大于82%，天线的峰值增益大于9.5dBic，最大辐射效率为88%，在工作频带内，天线的辐射方向图保持对称和稳定，综合性能指标在领域内处于领先水平，项目研究工作具有重要的科学意义；同时，该天线具有体积小、重量轻、易实现、低成本等诸多优点，对宽带定向圆极化天线在新型多功能无线通信系统中的应用具有很好的指导意义；本项目研究成果将广泛应用于新一代移动通信系统、卫星导航与通信系统、物联网系统，在我国大力培育和发展战略性新兴产业的大背景下，所在课题组已与多家高新技术企业开展了产学研合作，项目研究成果具有很好的应用前景和广阔的市场空间，可以产生良好的经济效益和社会效益。