基于Zadoff-Chu序列的频控阵稳健波束成形方法

A Robust Beamforming Method for Frequency Diverse Array Based on Zadoff-Chu Sequence

不同于传统相控阵,频控阵(Frequency Diverse Array,FDA)在所有阵元间引入频率偏差,可以生成具有精准指向特性的点状辐射方向图,有效克服传统相控阵方位角相关性导致的接收方向射频信号安全性下降的问题。作为与传统相控阵的本质区别,FDA阵元频偏设置直接影响FDA辐射方向图的形状。为了生成理想的点状方向图,提出了一种Zadoff-Chu FDA(ZC-FDA)稳健波束成形方案,利用Zadoff-Chu序列调整阵元频偏,消除FDA辐射方向图周期性,抑制距离-方位角耦合性。与现有FDA系统相比,ZC-FDA方案在理想点状辐射方向图生成和波束旁瓣水平抑制方面具有明显优势。

Different from conventional phased array,frequency diverse array(FDA)leads a small frequency increment into each array element,which results in a dot-shaped beampattern with precisely pointing characteristics.Consequently,FDA can overcome the problem of security degradation in conventional phased array caused by the radiated radio signal at desired transmission direction.The frequency offset of array elements,as the most essential difference between conventional phased array and FDA,significantly affects the shape of propagation beampattern.In order to obtain a concentrated dot-shaped beampattern,a Zadoff-Chu FDA(ZC-FDA)is proposed in which the frequency offset is adjusted on the basis of a Zadoff-Chu sequence to remove the periodicity and range-angle coupling.Numerical results show the superiority of the proposed ZC-FDA in terms of dot-shaped beampattern generation and lower sidelobe level.