变形螺旋天线的自动设计

 利用优化算法进行天线的自动设计是现代天线研究的一个重要趋势。采用NEC(Numerical Electromagnetics Code)天线数值计算程序和遗传算法，结合并行计算技术，实现了对螺旋天线的自动设计。在轴向模辐射，螺旋轴长80cm内和频率为600MHz的条件下，设计了增益高达12.68dB的均匀螺旋天线，比传统设计方法高3.28dB；在400～800MHz的频带内，对变形螺旋天线之一的锥削螺旋天线做了高增益设计，平均增益达12.28dB；对锥削螺旋-圆锥喇叭天线进行了优化设计，得到了比普通螺旋天线更佳的辐射性能。这些设计结果都是传统天线设计方法难以完成的，表明自动设计具有比传统天线设计方法更大的灵活性和更强的设计能力。

Automated design of modified helical antennas

Automated antenna design has already become the latest trend of antenna design. An approach, which is based on the genetic algorithm (GA) and the NEC2 (numerical electromagnetics code, version 2) in conjunction with the parallel computation technique, is explored in this paper to design and optimize helical antennas. Three kinds of antennas have been optimized by the approach: a uniform helical antenna with a gain of 12.68dB, which is 3.38dB higher than that created by traditional design methods;a tapered helical antenna with average gain 12.28dB in frequency band 400～800MHz;and a tapered helix-conical horn antenna. Results show the approach is more efficient than traditional design methods and can solve different antema design problems of widely varying complexity, including those too difficult to attempt with traditional design methods.