双频带多层耦合广义斯涅尔表面建模及其在波束扫描天线中应用的研究

Beam-scanning antennas are an important category of RF components in Radar and Satellite Communication Systems. Limited by their geometric designs as well as hardware requirements, it is difficult for conventional beam-scanning antennas to make further reduction on size, weight, and power consumption. One possible solution for miniaturization and further power reduction for such antennas is through the application of novel microwave metamaterials such as microwave gradient surfaces. This project proposes to resolve the drawbacks of limited scanning angles of conventional active gradient surface by introducing a coupled multi-layer surface architechture based on the generalized Snell's Law. Key research topics will be covered such as the circuit modeling and design of unit cells of multiband generalized Snell's surface, modeling of mechanisms of coupling between multiple surfaces, and model of the coupling of radiation sources and the genralized Snell's surface superstrates. In light of the aforementioned research effort, the project try to establish the design methodology of 2D multiband beam refraction based on generalized Snell's Law, and the near-field coupling model of unit cells between multilayer surfaces, as well as an optimized allocation of beam refraction angles between respective layers. As a validation, a novel dual-band beam scanning antenna with a low profile, high gain, low power consumption, and a large scanning angle will be realized. The proposed project will contribute with an important role in the application of radar systems and satellite communication systems on novel small mobile platforms and wearable platforms.

波束扫描天线是雷达探测与卫星通信系统射频端的重要组成部分。传统波束扫描天线受天线几何构型、硬件架构等限制，在天线尺寸、重量、功耗的缩减方面很难有进一步突破。利用新型微波材料，如微波梯度超表面等方式构建波束扫描天线是实现天线小型化、低功耗的重要途径之一。本项目基于广义斯涅尔定律原理，提出利用多层广义斯涅尔表面耦合解决传统有源梯度表面波束偏转角有限的缺陷，通过解决多频段广义斯涅尔表面单位元结构电路建模、多层广义斯涅尔表面单位元之间互耦物理机制、辐射源与广义斯涅尔表面天线罩的近场耦合建模等关键问题，确立基于广义斯涅尔定律的二维多频段波束偏转设计理论与方法及多层广义斯涅尔表面单元的近场耦合模型，并优化多层广义斯涅尔表面间波束偏转量分配，最终实现双频带，低剖面，高增益，低功耗，大扫描角的新型波束扫描天线。研究项目对于雷达探测系统与卫星通信系统在新型小型移动平台、穿戴式平台中的应用具有重要的推动作用。

波束扫描天线是现代卫星通信系统、雷达探测系统射频端的重要组成部分，其设计目的为产生窄波束、高增益的辐射方向图，且具备跟随卫星、地面基站通信链路方向或雷达扫描方向变化实时调整波束角度指向的能力。针对这一背景，本项目拟对基于广义斯涅尔定律的梯度表面开展研究，确立适合于二维波束偏转的，可工作于双频带的有源梯度表面单元结构，并建立基于广义斯涅尔定律的二维双频带波束偏转设计理论与方法，并建立多层广义斯涅尔表面单元的近场耦合模型，设计工作于多个波段的波束扫描天线阵，对利用上述原理实现小型化、低剖面、低功耗波束扫描进行原理验证与测试。.在本项目的开展过程中，项目组成员针对高增益超材料天线的设计，以及基于梯度超表面的波束扫描方法设计开展了理论研究，并进行了理论推导。基于上述理论推导，设计了超材料高增益天线设计方法与原型，以及波束扫描天线设计方法与原型，并进行了仿真测试与验证。最终研究成果为超材料天线设计原理方法、以及超材料天线设计原型。