超电小尺寸三维加载Metamaterial双向吸波器理论及其在紧凑型圆极化微带天线阵列中的解耦应用研究

Today, satellite navigation and positioning terminals (SNPT) play a quite significant role in many fields, particularly in precision guided weapons. However, they could fail in a complicated electromagnetic environment due to a group of rather weak navigation signals in a level of around -160dBW travelling more than 20000 kilometers from some satellites. For instance, usually there are several strong jammings around the SNPTs in a so-called complicated electromagnetic environment. At present, it is only partially successful to suppress jamming by adopting an adaptive antenna array (AAA) in the SNPTs because there are serious mutual couplings arising between elements in the array, which may lead to serious distortion in the radiation pattern of each element. Thus, how to decouple elements in the AAA becomes our focus to improve the performance of the SNPTs. Fortunately, some new born electromagnetic metamaterial absorbers (MMA) of some advantages, such as wide-bandwidth, wide incident angle, polarization-insensitivity, ultra-thin thickness, and etc., could be potentially applied in decoupling. Although these MMAs cannot be used directly in the AAA due to their relatively large dimensions and bianisotropic property (uni-directivity), we are inspired to research and design a more compact and bi-directional MMA. In the proposal, we are going to complete the following works: 1) to investigate and optimize a super compact L band MMA in theory, numerical simulation, designing method and test technique, which is three-dimensionally loaded by multi lumped elements based on our previous achievements; 2) to discover and demonstrate the impact of the mutual coupling on the radiation performance of each element in the AAA through theory analysis, numerical and physical experiments in order to confirm the optimal position for fixing MMAs; 3) to implement a MMA, fix it into an AAA in a Beidou ground navigation and positioning terminal and make a series tests for evaluating the effect of the novel MMA on the performance of the AAA, even on the performance of the corresponding SNPT.

卫星导航定位终端在高精制导武器以及民用测量领域举足轻重，但因导航卫星远离地面，到达地面终端的导航信号极其微弱（约-160dBW），因此极易受干扰，导致终端在恶劣电磁环境下失效。采用自适应天线阵列能在一定程度上抑制干扰，但因阵元间距过近，存在严重互耦，阵元辐射方向图产生畸变，抑制效果不甚理想。因此降低阵元互耦成为提高卫星导航定位终端性能的重要手段之一。随着超材料研究的兴起，最新出现的超材料吸波器为降低天线阵元互耦，改善阵元辐射特性提供了可能。本项目拟实现：1）基于现有基础，对紧凑型三维加载超材料吸波器展开深入研究，包括基本理论、仿真模型、设计方法和测试方法等；2）针对多阵元圆极化微带天线阵列，通过理论分析、数值仿真和实物测试，探讨互耦对阵元辐射特性的影响，并确定超材料吸波器的最佳安置位置；3）加工超材料吸波器，安置于北斗二代地面终端四阵元抗干扰天线阵列，评估其对天线阵性能的改善效果。

卫星导航定位终端在高精制导武器以及民用测量领域举足轻重，但因导航卫星远离地面，导致到达地面终端的导航信号极其微弱（约-160dBW），因此极易受干扰，在恶劣电磁环境下失效。采用多阵元自适应天线阵列能在一定程度上抑制干扰，但因阵元间距过近，阵元间存在严重互偶，阵元辐射方向图产生畸变，抑制效果不甚理想。因此降低阵元互偶成为提高卫星导航定位终端性能的重要手段之一。随着超材料研究的兴起，最新出现的超材料吸波器为降低天线阵元互偶，改善阵元辐射特性提供了可能。本项目实现了：1）基于现有基础，对紧凑型三维加载超材料吸波器展开深入研究，包括基本理论、仿真模型、设计方法和测试方法等；2）针对多阵元圆极化微带天线阵列，通过理论分析、数值仿真和实物测试，明确了互偶对阵元辐射特性的影响，确定了超材料吸波器的最佳安置位置；3）加工了超材料吸波器，安置于北斗二代地面终端四阵元抗干扰天线阵列，评估了其对天线阵列抗干扰性能的改善效果，实测结果表明超材料吸波器能够有效的改善紧耦合圆极化微带天线阵列的互耦特性，达到-25dB以上，同时构架的实际测试系统表明，对于宽带干扰（单干扰），系统抗干扰能力达到110dB水平。