双层方环可电控FSS吸波屏设计和实验研究

Design and measurement of active absorber using the double layer square loop FSS

提出了基于双层方环FSS结构的可电控吸波屏,通过加载PIN二极管在X波段实现了对FSS吸波屏吸波性能的电流控制。加工制作了可电控吸波屏的实验样品板并进行了实验测试,分别测量了垂直入射与斜入射情况下、电场极化同PIN管极性所趋方向相同时吸波屏的反射率频响曲线,曲线中保证有效吸收的频带区域的动态迁移范围覆盖了整个X波段。实验结果表明:该吸波屏能够有效吸收入射电磁波,其吸波性能经电流的控制可满足不同的带宽要求,且带宽的可电控特性在垂直入射与斜入射时均达到了预期的目标,体现了双层方环型FSS吸波屏对多角度入射波的适应性。

An active microwave absorber based on FSS with double layer square loop patterns is presented for specifically polarized plane waves. The absorption ability of the absorber can be controlled over the entire X band by the bias current applied through PIN diodes. The experimental board is fabricated and the measurement is made to obtain the reflectivity response curves of the absorber responding to both normal and oblique incident plane waves when the electric intensity is in the direction of PIN polarity. The dynamic bandwidths in which the reflectivity curves are lower than the prescribed level can cover the entire X band. The measured re- suits validate the absorption ability of the design and indicate that the bandwidth can be shifted to meet various external requirements by the current control. The double layer square loop geometry achieves the expected tunable reflectivity bandwidth for both the normal incidence and the oblique incidence, confirming its stability of absorption ability with incidence angles.