Du Zhiqiang, Liang Jiangang, Cai Tong, Wang Xin, Zhang Qingdong, Deng Taowu, Wu Borui, Mao Ruiqi, Wang Dengpan
Opt Express. 2021 Mar 1;29(5):6434-6444. doi: 10.1364/OE.416245.
Absorbers have high potential application values in the military field, such as electronic screening, radar cross-section reduction and invisible cloaking. However, most methods have the defects of narrow bandwidth, low absorptivity, complex three-dimensional structure and fixed polarizations. In this paper, we realize an ultra-broadband and full-polarization planar metamaterial absorber (PMA) with a three-layer composite structure, which exhibits multi-resonant and impedance matching properties by combining the ultra-light foams and indium tin oxide (ITO) films. The bottom two layers achieve a high-efficiency absorption rate at the low and medium spectrum, while the upper layer realizes a absorption property at a high frequency. Also, an equivalent circuit model is extracted to explain its operating mechanism. The experimental results show that our meta-absorber can achieve great absorber performance of better than 90% within 1-18 GHz for full-polarization incident waves, which is in great agreement with the numerical simulations. Moreover, our device is insensitive to oblique incidences and polarizations and possesses the physical characteristics of an ultralight, weighing 0.6 kg for a square meter, which is only 1/85.0-1/126.7 of the conventional absorbers under the same size. All these excellent performances determine that our research can be a good candidate for military stealth materials.
吸收体在军事领域具有很高的潜在应用价值，如电子屏蔽、雷达散射截面缩减和隐形伪装。然而，大多数方法存在带宽窄、吸收率低、三维结构复杂和极化固定等缺陷。本文中，我们实现了一种具有三层复合结构的超宽带全极化平面超材料吸收体（PMA），通过结合超轻泡沫和氧化铟锡（ITO）薄膜展现出多谐振和阻抗匹配特性。底部两层在低频和中频实现了高效吸收率，而上层在高频实现了吸收特性。此外，提取了等效电路模型来解释其工作机制。实验结果表明，我们的超材料吸收体对于全极化入射波在1-18 GHz范围内可实现优于90%的出色吸收性能，这与数值模拟结果高度吻合。而且，我们的器件对斜入射和极化不敏感，具有超轻的物理特性，每平方米重0.6 kg，在相同尺寸下仅为传统吸收体的1/85.0-1/126.7。所有这些优异性能表明我们的研究可为军事隐身材料提供良好选择。
