Deng Taowu, Liang Jiangang, Lou Jing, Zhang Chiben, Du Zhiqiang, Wang Canyu, Cai Tong
Opt Express. 2021 Mar 1;29(5):7558-7567. doi: 10.1364/OE.420063.
Perfect absorbers are highly desired in many engineering and military applications, including radar cross section (RCS) reduction, cloaking devices, and sensor detectors. However, most types of present absorbers can only absorb space propagation waves, yet absorption for the surface wave (SW) has not been researched intensively. In reality, when the space wave illuminates on the metal under large oblique angles, surface waves can be excited on the interface between metal and dielectric and thus would increase the RCS and influence the stealth performance. Here, based on the wave vector and impedance matching theories, we propose a broadband absorber for the surface wave under spoof surface plasmon polariton (SSPP) mode. The former theory ensures that surface waves can enter the absorber efficiently, and the latter guarantees perfect absorption. The experimental results indicate that our absorber can achieve a broadband (9.4-18 GHz) performance with an absorption ratio better than 90%, which is in great agreement with the simulations. Therefore, our device can be applied in RCS reduction for the metal devices, antenna array decoupling and many other applications. Also, this work provides a unique methodology to design new types of broadband surface wave absorbers.
在许多工程和军事应用中，包括雷达散射截面（RCS）缩减、隐身装置和传感器探测器等，完美吸收体备受青睐。然而，目前大多数类型的吸收体只能吸收空间传播波，而对表面波（SW）的吸收尚未得到深入研究。实际上，当空间波以大倾斜角照射到金属上时，金属与电介质界面上会激发表面波，从而增加雷达散射截面并影响隐身性能。在此，基于波矢和阻抗匹配理论，我们提出了一种基于类表面等离激元极化激元（SSPP）模式的表面波宽带吸收体。前一种理论确保表面波能够有效地进入吸收体，而后一种理论保证了完美吸收。实验结果表明，我们的吸收体能够在9.4 - 18 GHz的宽带范围内实现吸收率优于90%的性能，这与模拟结果高度吻合。因此，我们的器件可应用于金属器件的RCS缩减、天线阵列去耦以及许多其他应用。此外，这项工作为设计新型宽带表面波吸收体提供了一种独特的方法。
