为实现频率选择表面(FSS)谐振频率的光电可调控特性, 提出一种光电可调控频率选择表面.利用光电导薄膜光照导电特性控制金属FSS结构尺寸变化, 实现FSS的主动可调.理论阐述了光电导及FSS选频特性原理, 采用CST软件分别仿真了“Y”形带通型、“圆”形带通型和“Y”形带阻型三种FSS在光照时的频选特性.结果表明: 随着结构尺寸变化, FSS的中心谐振频率分别从18 GHz、25 GHz、20.5 GHz变为20.5 GHz、29 GHz、16.5 GHz.采用镀膜、刻蚀及电子束蒸发等技术分别制作了单元结构尺寸变化前的金属FSS, 以及变化后的金属与光电导薄膜结合的FSS, 并对样件进行测试, 结果表明: 中心谐振频率分别从18 GHz、24 GHz、20 GHz变为20 GHz、28 GHz、17 GHz, 与仿真变化趋势基本一致.采用该方法既可实现FSS中心谐振频率的可调控, 也可从结构上实现FSS带通型和带阻型的转变.

To achieve the photoelectric controllable characteristics of Frequency Selective Surface (FSS) resonant frequency, a photoelectric controllable FSS is put forward in this paper. The photoconductive thin film is used to control the change of the structure size of FSS, so as to realize the controllability of FSS. This thesis starts from the theory of the photoconductive thin film and the principle of the characteristics that FSS can select frequency. The CST software was used to simulate three kinds of FSS: “tripole” slot-element, “circular” slot-element, “tripole” patch-element, and get the selecting frequency characteristics of different structure sizes. The simulation result shows that, with the changing structure size, the center resonant frequency of the FSS changes from 18 GHz, 25 GHz, and 20.5 GHz to 20.5 GHz, 29 GHz, and 16.5 GHz respectively. Finally, the metallic FSS with the unchanged structure size, and the FSS of the metal and the photoconductive thin film combined, were fabricated by coating, etching, electron beam evaporation and so on. Test the samples and the result shows that the center resonant frequency changes from 18 GHz, 24 GHz, 20 GHz into 20 GHz, 28 GHz, 17 GHz. Compared with the simulation results, the trend is about the same. Ultimately, we can draw the conclusion: in this way, not only can we realize the characteristic of controlling the center resonant frequency, but also we can achieve the conversion of slot-element or patch-element in the structure of FSS.