口径耦合微带天线阵的互耦研究

针对微带天线阵阵元之间互耦的复杂性,给出了用时域有限差分法对口径耦合微带天线直线阵互耦现象进行分析的方法.该方法以口径耦合微带天线单元构成的7单元直线阵为研究平台,借助仿真软件Empire获取数据,结合直线阵和传输线理论导出相应计算公式,并用Matlab进行数据处理.应用该方法分析了互耦阵列的行为,给出了互耦系数的计算方法及其在天线设计中的应用方法.分析结果表明:由于互耦的存在及影响,使中心位置馈电天线阵的方向图出现旁瓣,边缘位置馈电的方向图出现非对称形状;互耦系数随着与馈电单元距离的增大急剧下降,距离4个阵间距以上的天线单元其模值下降到0.01以下.通过实例将该方法分析结果与仿真曲线进行了对比,其吻合程度验证了该方法的精确性.为在互耦状态下微带天线阵的设计提供了参考.

Research of Mutual Coupling of Aperture-Coupled Microstrip Antenna Arrays

Aiming at the complexity of the mutual coupling among microstrip-antenna-array elements, the analysis of mutual coupling phenomenon on aperture-coupled antenna arrays is carried out by using FDTD(Finite-Different Time-Domain) method. The research platform is on the basis of seven-element linear arrays composed by aperture-coupled antenna element. The software Empire based on FDTD is used to obtain data and the relevant computing formula is educed combined with the theory of linear arrays and strip, and the data are processed with Matlab. The action of mutual coupling arrays is analyzed, the computing and application method of mutual coupling coefficient in the design of antenna arrays are presented. The result shows that a side petal appears in the central position of the feeding antenna arrays direction because of the existence and influence of mutual coupling and a dissymmetry appears in the margin. The mutual coupling coefficient decreases sharply with the increase of the interval between feeding elements, the module value of antenna element with more than four array interval decreases below 0.01.The analysis results on this method are compared with simulation curves through practical example and the accuracy of this analytical method is proved. It provides a reference to design microstrip antenna in the mutual coupling state.