双屏频率选择表面结构的遗传算法优化

双屏频率选择表面能够更好地实现平顶效应和快速下降的边缘,是一种实现雷达舱对探测带外雷达波隐身的有效手段.本文针对双屏频率选择表面(FSS)在电磁波不同角度入射下的宽带通应用,采用遗传算法对FSS介质厚度、介电常数、单元图形、排列周期进行了整体优化,给出优化后的FSS结构和传输特性曲线;同时采用镀膜和光刻技术制备出相应的实验件,在微波暗室进行了测试.结果表明,优化后的结构在保证2 GHz的工作带宽下,对电磁波的入射角度有良好的传输稳定性,这为实现双屏FSS在曲面大角度下的应用奠定了基础. 关键词： 频率选择表面 遗传算法 优化

Double screen frequency selective surface structure optimized by genetic algorithm

Double screen frequency selective surface(FSS) is a very effective means of realizing the invisibility of radar-cabin from the detection of radar wave since it can well realize the flattened effect and rapid decrease. In this paper, the thickness, the dielectric constant, the element graph and the arrangement periodicity of an FSS medium are investigated by Genetic Algorithm(GA) when electromagnetic waves are incident on the double screen FSS at varying angles, and an optimized FSS structure and transmission characteristics are obtained. Meanwhile, the relevant experimental samples are prepared by means of coating and lithography and are tested in microwave anechoic chamber. The results show that the optimized structure has a better stability with respect to incident angle of electromagnetic wave under the condition of 2GHz operation, thereby laying the foundation for the application of double screen FSS to curved surfaces at wide angles.