基于FFT的大型平面阵列方向图的综合方法

Pattern synthesis method for large planar two-dimensional arrays using FFT

针对大型平面二维阵列,提出了一种快速的综合方法。首先根据单元激励初值,应用二维离散傅里叶逆变换(invert fast Fourier transform,IFFT)得出阵列方向图,然后与期望方向图比较,得出新的方向图,再应用二维快速傅里叶变换(fast Fourier transform,FFT)反算出新的单元激励。如此反复,直到方向图满足设计要求。该算法直接对大型平面二维阵列进行优化而不是针对一维线阵或小型阵列,而且天线单元数大于5 000。最后两个6 400(80×80)单元阵列的仿真结果表明该方法实用、高效。

A pattern synthesis method for large planar two-dimensional arrays is proposed. Firstly, starting with an initial set of element excitations, the array pattern is calculated by using two-dimensional invert fast Fourier transform （IFFT）. Secondly, after matching the array pattern to the desired pattern, a new set of excitations is obtained through two-dimensional fast Fourier transform （FFT） performed on the matched array pattern. Repeat the whole process until the array pattern satisfies the pattern requirements. This method directly optimizes the large planar two-dimensional array rather large planar array exceeds 5 000. Finally, the results of than linear and small planar arrays, and the size of the two 6 400-element （80 × 80） planar arrays are presented to demonstrate the high efficiency and practicality of the method.