基于无人机集群的近场线性稀疏阵列波束形成研究

无人机集群构成的天线阵列常呈现近场、稀疏特性，经典波束形成理论无法适配。为此，该文首先构建了近场均匀线阵信号模型，通过对信号相位差函数进行泰勒展开近似提出基于线性调频脉冲压缩处理的近场波束形成简化实现方法，并以此为基础在空间-频率2维域内对近场波束形成特性进行了分析:从空间频率偏移和带宽失配的角度，分析得到了近场波束的方位向增益变化特性和距离向增益变化特性；从空间欠采样的角度，研究提出了阵元稀疏分布条件下近场波束栅瓣分布的解析表达式。仿真证明了该文结论的有效性，为利用波束形成技术提高无人机集群的通信、电子侦察、干扰能力提供了理论支撑。

Beamforming Research for Near-field Linear Sparse Array Based on Unmanned Aerial Vehicle Swarm

The antenna array composed of UAVs (Unmanned Aerial Vehicle Swarm) often presents near-field and sparse characteristics, which can not be adapted by the classical beamforming theory. Therefore, the near-field uniform linear array signal model is first constructed, and a simplified implementation method of near-field beamforming based on linear frequency modulation pulse compression by Taylor expansion of the signal phase difference function is proposed. Then the characteristics of near-field beamforming are analyzed in the two-dimensional space-frequency domain. From the perspective of spatial under sampling, the analytical expression of near-field beam grating lobe distribution under the condition of sparse array elements is proposed. From the perspective of spatial frequency offset and bandwidth mismatch, the variation characteristics of azimuth gain and range gain of near-field beam are analyzed and obtained. Simulation results show the effectiveness of the conclusions, and provide a theoretical support for using beamforming technology to improve the communication, reconnaissance and jamming capabilities of UAVs.