智能天线波达方向的互耦分析

Mutual Coupling Effects Correction in Smart Antenna Arrays for Direction-of-arrival Estimation

智能天线中阵元间互耦的存在,严重影响了天线的性能。基于分析天线阵列模型中阵元间的相互关联的特征的方法,用网络等效的方法描述天线发射、接收场与输入、输出信号之间的关系,即用一个新的网络来表示互耦情况下的电流分配,于是天线阵列可以表示为一个(K+1)*N端的网络,此网络的每个天线元由一个输入端,K个输出端构成(一个输入端是指天线元的馈电端,K个输出端是指假想的辐射函数),当只考虑一个辐射模式时,就可以得到2N端网络,根据网络构造互耦矩阵C,用C矩阵来修正波达方向估算中的互耦,并在MUSIC算法中实现。该方法理论分析与计算仿真表明该算法切实可行,有效并易于实现。

The presence of mutual coupling severely degrades the performance of an adaptive array.A simple method is based on obtaining an network.This new network takes into account the decomposition of the current distribution in multiple characteristic modes.Then any array antenna can be represented as a（（k＋1）＊N-network.The new network has one input and k output ports corresponding to any of the radiating modes of each antenna（by input ports it means any of the actual probes of the array.while by output ports it means fictitious ports representing any radiating function）.When the radiating elements are resonant antennas,only one radiating mode may be considered,it results in a 2N-port network,obtains coupling matrix C to compensate the coupling characteristic mode in conjunction with an element-by-element analysis of finite arrays.The method significantly reduce the computational effort in calculating the unknowns.Its application to the MUSIC algorithm results in good and efficient performance.