一种阵列天线快速波束赋形方法

Synthesis of the Shaped-beam Array Antennas Using a Fast Algorithm

介绍了一种阵列天线快速赋形方法,该方法基于Orchard综合,采用遗传算法对Schelkunoff单位圆零点的位置移动实现波束赋形。波束赋形分为两个步骤:1)根据副瓣电平采用解析法确定初始零点位置;2)以赋形区域内零点径向位移作为自由度,用遗传算法进行赋形区域单目标寻优。相对常见以阵元的幅度相位作为自由度编码的遗传算法赋形,该方法不仅有效避免了副瓣和赋形区的多目标均衡问题,而且算法自由度大幅减少,收敛速度快,能够同时实现较低副瓣电平和赋形区精度要求。通过余割平方赋形和扇形波束两个实例说明该方法的有效性,可以应用于阵列天线快速赋形设计。

A fast algorithm for synthesis of the shaped-beam array antennas is presented. This algorithm is realized by moving thezero point positions on the Schelkunoff^s unit circle using genetic algorithm, based on the Orchard synthesis. The procedure is dividedinto two steps ： 1） analytically calculate the original zero point positions according to the side lobe level; 2） the freedom ofzero point movement in the shaping area is restricted in the radical direction, and find the best result with single-target by geneticalgorithm. Compared to the normal antenna shaping using amplitude-phase coding in the genetic algorithm, this method can avoidthe multi-objective trade-off between the side lobe level and beam shaping accuracy efficiently, and the freedom of variable for thealgorithm is reduced, the convergence velocity is also enhanced dramatically. Besides, low side lobe level and beam shaping withhigh precision can be realized simultaneously. The efficiency for this algorithm is verified by shaped square-cosec and fan beamsample, and it can find wide applications in the area of fast beam shaping for the array antennas.