多模式及多极化频率扫描可重构天线研究

Reconfigurable antenna is one of the very important research directions in the investigation of communication system. It can not only reduce the cost of the RF front-end system and the probability of electromagnetic interference, but also provide important technical support for increaseing the capacity of wireless communication system, expanding the system functionality, and widening system bandwidth. Reconfigurable antenna can be well applied to radar, remote sensing, satellite, terminal tracking, MIMO systems, and software defined radio, which will have a far-reaching impact on the wireless communication technology. This project investigates the multi-pattern, multi-polarization and frequency-scanning substrate integrated waveguide reconfigurable antenna. The main innovations of the project are that the antenna array can achieve the frequency scanning and electronically-controlled pattern reconfigurable functions at the same time, can realize polarization reconfigurability by controlling new feeding network, and can be applied to a variety of communication system applications with multiple reconfigurable functions. The researches include the design of frequency-scanning antenna unit and array structure, the design of two orthogonal linearly polarizated frequency-scanning antenna unit and array structure, the design of multi-pattern frequency-scanning antenna unit and array structure, multi-polarization frequency-scanning antenna array design, and accordingly the fabrication and test of the prototypes to vertify the reconfigurability. Through the research of this project, the characteristics of reconfigurable antenna array can be mastered, which will provide help and guidance for the development of intelligent communication system.

可重构天线技术是通信系统研究的一个很重要的研究方向。它不仅可以降低射频前端系统的成本，减少电磁干扰，而且还可以为提高无线通信系统容量、扩展系统功能、增加系统工作带宽等提供重要的技术保障。可重构天线能够很好地应用于雷达、遥感、卫星、终端探测、MIMO系统、软件无线电，将对无线通信技术带来深远的影响。本项目研究多模式及多极化可频率扫描的基片集成波导可重构天线。主要创新点是：同时实现天线阵的频率扫描和电子调控模式可重构；通过新型馈电网络控制，实现天线阵极化可重构特性；多种天线阵可重构功能，适用于多种通信系统应用。研究内容包括：频率扫描天线阵阵元和阵列结构研究、正交双线极化频率扫描天线阵阵元和阵列结构研究、多模式频率扫描天线阵阵元和阵列结构研究、多极化频率扫描天线阵特性研究及相应的样机设计和特性验证。通过本项目研究工作，可以掌握可重构天线阵特性，为发展智能通信系统提供指导。

现代无线通信技术发展迅速，可重构天线凭借可实时重构特性的优势，在现代通信系统的发展中发挥着重大的作用，特别是其中的复合可重构天线能够同时实现多种工作性能（频段、方向图、极化方向）的调控，已成为天线领域的研究热点。本项目研究了多模式多极化频率扫描的复合可重构天线，此天线为基于半模基片集成波导的复合左右手结构的漏波天线。首先分析了半模基片集成波导的传输特性，并在此基础上设计了复合左右手单元及阵列排布，完成了正交线极化的频率扫描天线的研究；其次分析设计了基于基片集成波导的3dB定向耦合器，并进行正交双线极化天线的排布，完成了频率扫描左右旋圆极化可重构天线的设计；然后分析了加载电调元件的复合左右手单元及阵列排布，完成了多模式（方向图连续可调）多极化的频率扫描天线设计。另外，由于项目中涉及高频段变容二极管的应用，为了评估变容二极管在高频的寄生参数影响，设计了变容二极管射频参数提取平台。本项目所述天线具有半模基片集成波导低剖面、易共形、低损耗、高功率容量、小型化的优点，且因为复合左右手结构具有后向-侧射-前向的波束扫描的能力，兼具漏波结构宽频带性能，具有很大的研究意义与应用价值。