基于子阵激励能量匹配的多子阵交错阵列设计

多子阵稀疏交错共享孔径阵列天线是实现多功能阵列天线设计的有效途径。提出了一种基于子阵激励能量匹配的多子阵稀疏交错优化方法。根据均匀线阵激励与其方向图之间存在的傅里叶变换关系，该方法首先通过快速傅里叶变换（FFT）获得特定方向图的激励频谱能量分布，然后分析均匀线阵目标方向图频谱能量的分布特征，采用交叉选取子阵激励的方法，确定各子阵单元位置，使得阵列天线单元激励能量均匀分配，从而确保各子阵方向图近似一致。在此基础上通过迭代FFT的方法降低各子阵天线方向图旁瓣峰值（PSL），实现低旁瓣，同性能的多子阵交错共享孔径阵列天线设计。仿真研究与实验表明，通过本文提出多子阵交错方法设计的共享孔径多稀疏交错子阵具有运算量小、孔径利用率高、各子阵峰值旁瓣电平低且拥有相似方向图的优点。利用子阵交错的方法，通过控制各子阵主波瓣指向，能轻松实现多波束指向的多功能阵列天线设计。 

Design of array with multiple interleaved subarrays based on subarray excitation energy-matching

The shared aperture array antennas with multiple interleaved subarrays is an effective solution of the design of multi-functional array antennas. A new method for interleaving multiple subarrays based on excitation energy-matching is proposed in this paper. In light of the Fourier transform mapping between the element excitations and array factor of uniform linear array, the spectrum of the array factor is first obtained by fast Fourier transform (FFT) and its excitation energy distributions are analyzed thoroughly. The element positions are then selected carefully in a staggered way which ensures that the uniform distribution of the excitation energy of the array antenna elements and the similar patterns can be obtained. Then the peak sidelobe levels (PSL) of the subarrays are reduced with the iterative FFT algorithm. Futhermore, the design of shared aperture antenna array with low sidelobe levels and same performance is achieved. Some numerical simulations and experiments demonstrate that the interleaved subarrays generated from the proposed method possess many favorable characteristics, such as, reduced computational burden, high aperture efficiency, lower PSL than the random thinned array, and perfect matched patterns. By controlling the mainbeam direction, the multi-functional array antenna can be easily designed with multiple beam lobes.