Wang Jiayun, Yang Rongcao, Xu Jianping, Tian Jinping, Ma Runbo, Zhang Wenmei
School of Physics and Electronic Engineering, Shanxi University, Taiyuan 030006, China.
Materials (Basel). 2018 Sep 5;11(9):1619. doi: 10.3390/ma11091619.
In this paper, a polarization-controlled and flexible metamaterial absorber made of a set of wires etched on ultrathin teflon dielectric substrate is proposed. The simulation results showed that the proposed absorber achieved single-band absorptivity of 99.8% at 6.64 GHz for the TM (transverse magnetic) polarization wave and penta-band absorptivity of more than 99% at 11.68 GHz, 13.58 GHz, 15.48 GHz, 17.38 GHz, and 19.28 GHz for the TE (transverse electric) polarization waves. Moreover, each absorption peak had very narrow relative bandwidth and the position of penta-band absorption peaks could be adjusted by changing the length of the corresponding wire or selecting suitable substrate material according to actual requirements, because each wire can independently respond to electromagnetic (EM) waves. Furthermore, the surface current distributions corresponding to each absorption peak were studied to demonstrate the absorption mechanism. The absorption properties of the proposed structure with different bending radii and under different incident angles of the EM waves were investigated, showing good flexibility and incident angle-insensitive properties. In addition, the simulation results were confirmed by measuring a fabricated prototype. The proposed absorber may have useful applications in polarizers, sensors, bolometers, polarization detectors, etc.
本文提出了一种由蚀刻在超薄聚四氟乙烯介电基板上的一组金属线制成的偏振控制柔性超材料吸波器。仿真结果表明，所提出的吸波器对于TM（横向磁）偏振波在6.64 GHz处实现了99.8%的单波段吸收率，对于TE（横向电）偏振波在11.68 GHz、13.58 GHz、15.48 GHz、17.38 GHz和19.28 GHz处实现了超过99%的五波段吸收率。此外，每个吸收峰具有非常窄的相对带宽，并且五波段吸收峰的位置可以根据实际需求通过改变相应金属线的长度或选择合适的基板材料来调整，因为每条金属线可以独立地响应电磁波。此外，研究了与每个吸收峰对应的表面电流分布以阐明吸收机制。研究了所提出结构在不同弯曲半径和不同电磁波入射角下的吸收特性，显示出良好的柔韧性和对入射角不敏感的特性。此外，通过测量制作的原型证实了仿真结果。所提出的吸波器可能在偏振器、传感器、测辐射热计、偏振探测器等方面有有用的应用。
