螺旋天线的快速分析及宽带化设计

研究了一种快速计算螺旋天线电特性的新方法，并结合遗传算法对天线进行了宽带、小型化设计。采用直线段对法向模螺旋天线进行划分，应用合成基函数及合成检验函数的矩量法对阻抗矩阵进行了降阶处理，节省了求解矩阵方程所需的时间和存储量。结合遗传算法对加载法向模螺旋天线上的加载集总元件的值、加载位置以及匹配网络参数进行一体化优化设计，并采用Sherman-Morrison-Woodbury公式快速求解加载后的矩阵方程，提高了优化设计的效率。最后，成功设计了一副工作在100～1000MHz的宽带小型化螺旋天线。

Fast analysis and broadband design of the helical antenna

A fast algorithm is investigated for calculating the electric characteristics of a helical antenna, and the broadband miniature helical antenna is designed by Genetic Algorithm (GA). The piecewise-straight segments are used to model the normal mode helical antenna (NMHA), which can be analyzed by method of moments (MoM) with the Composite basis functions and the Composite testing functions. With the reducing of the rank of the impedance matrix, the CPU time and the memory storage will significantly saved. Then the loading circuit parameters, locations of the loads, and matching network parameters are optimized simultaneously by GA. With the application of The Sherman-Morrison-Woodbury formula in the load impedance matrix equation, the optimization efficiency will be improved. Finally, a broadband miniature helical antenna working on 100~1000MHz frequency band is successfully designed.