基于超材料的微波双波段吸收器

基于闭合双环单元结构, 设计、仿真、测试了对偏振无依赖性的双波段超材料吸收器. 实验结果表明, 该设计在频率4.06 GHz和6.66 GHz存在两个显著吸收峰, 吸收率分别为99.60%和95.83%, 并且在入射角达到50°时, 吸收率仍然保持在83%以上. 由于单元结构具有旋转对称性, 使得该吸收器对偏振不敏感, 能同时实现横电波和横磁波的双波段吸收. 吸收频率决定于闭合环大小, 调节闭合环尺寸能够灵活实现特定频率的吸收. 这些优点使我们的设计在多频谱成像、热辐射探测等应用中表现出较大的潜力.

Dual band metamaterial absorber in microwave regime

We report on the design, the fabrication and the measurement of a microwave dual band absorber in microwave regime. The single unit cell consists of two closed ring resonators and a metallic ground plane separated by an FR4 layer. Experimental results show that the absorber has two distinctive absorption peaks at frequencies 4.06 GHz and 6.66 GHz with absorptions 99.60% and 95.83%, respectively, and the absorptivity drops in a wide range of incident angle. Fourfold rotational symmetry of the geometry makes the absorber insensitive to transverse electric and transverse magnetic polarization. The dual band absorber is a promising candidate as absorbing elements in multi-frequency imaging and thermal detection, due to its multi-band absorption performance, polarization-insensitivity, and wide angle of incidence.