基于多阶等离激元谐振的超薄多频带超材料吸波体

本文设计了一种超薄螺旋结构超材料吸波体,其厚度(1.034 mm)约为其工作波长(4.81 GHz,6.59 GHz,9.16 GHz,12.69 GHz和13.71 GHz)的(1/60,1/44,1/32,1/23,1/21).仿真和实验结果表明,该吸波体在4.81 GHz,6.59 GHz,9.16 GHz,12.69 GHz和13.71 GHz处吸收率分别达到94.55%、99.89%、99.73%、99.26%和99.41%,实现了多频带强吸收.从表面电流和功率损耗密度两个方面分析了产生强吸收的原因,理论分析表明,多频带强吸收能在五个相邻频率处产生多阶局域表面等离激元谐振,螺旋结构之间强烈的电谐振使超材料结构单元产生强烈的吸收.该超材料吸波体设计简单、易于制作和应用,在电磁波吸收中具有应用价值.

Ultra-thin multiband metamaterial absorber based on multi-order plasmon resonances

In this paper, an ultra-thinspiral-structured metamaterial absorber is demonstrated both numerically and experimentally, whose thickness (1.034 mm) is about (1/60th, 1/44th, 1/32th, 1/23th, 1/21th) of the respective working wavelengths (4.81, 6.59, 9.16, 12.69 and 13.71 GHz). Simulation results show that the absorber can achieve absorption up to 94.41%, 99.89%, 99.73%, 99.26% and 99.41% at 4.81, 6.59, 9.16, 12.69 and 13.71 GHz respectively. Thus multi-band absorptions are realized. From the two aspects of surface current and power loss density, the mechanism of strong absorption is analyzed. Theoretical analysis shows that the multi-band absorption arises from multi-order plasmon resonances at five neighboring frequencies. Strong absorptions are induced due to strong electric resonances within/between the spiral structures. Design of the metamaterial absorber is simple and is easy to be implemented, so such absorbers may have application values in designing novel electromagnetic absorbers.
Keywords： multi-band metamaterial absorber spiral structure plasmon resonance