光纤相控阵稀疏排布优化算法对比

光纤相控阵在激光合束、激光雷达等领域具有应用前景.光纤阵列配置方式不同于微波相控阵,光纤天线间距大于波长时存在周期旁瓣问题,影响主瓣能量分布.本文从物理模型出发,建立了基于同心圆环形点阵集合的光学相控阵天线布阵理论模型,提出了利用解析延拓的傅里叶变换方法实现干涉场强度的快速合成理论,讨论了在离散采样时数值仿真需关注的采样带宽和采样数目问题,解决了快速实现多光束干涉场数值仿真的问题.对比研究了两种优化光学相控阵天线配置的优化算法:遗传算法和粒子群算法,分别实现了不同种群数量遗传算法和粒子群算法迭代优化,分析了二者在优化过程中的收敛速度和优化效果,得到了峰值旁瓣比PSR=0.270的配置阵列.所提出的方法有望用于实际的光学相控阵天线配置中,指导天线主瓣能量最大化的优化设计;研究模型对不可微分目标函数优化问题的研究有一定参考价值.

Comparison between optimal configuration algorithms of fiber phased array

Optical fiber phased array can be used in high-power laser beam combination,lidar and other areas.The configuration of the optical fiber array is different from the microwave phased array,which has periodic problems that affect the energy intensity distribution of the main lobe.Starting from the physical model,in this paper we establish a theoretical model of optical phased array antenna array based on a set of concentric circular ring lattices,and propose a theory of the rapid synthesis of randomly configured interference field strengths through using analytical continuation method and Fourier transform method.The problem of sampling bandwidth and sampling number that should be paid attention to in the numerical simulation of discrete sampling are discussed,and the problem of quickly realizing the numerical simulation of multi-beam interference field is solved.Genetic algorithm and particle swarm algorithm for optimizing the configuration of optical phased array antennas are investigated with different populations.The convergence speeds and optimization efficiencies of the two algorithms are compared and analyzed.It is demonstrated that the peak side-lobe ratio PSR can be achieved to be better than 0.270 by the genetic algorithm optimized configuration array under the real fabricate parameter.The proposed method is expected to be used in the actual optical phased array antenna configuration to guide the optimal design of the antenna with low side lobes,and the proposed model is also expected to provide a certain reference value for the study of optimizing the nondifferentiable objective function.