Broadband absorbing active metasurface for continuously and dynamically manipulate the absorptivity of...

As two-dimensional metamaterials, metasurfaces have attracted considerable research interest owing to their advantages of small volume and simple fabrication. By integrating the metasurfaces with active components controlled by electric bias, active metasurfaces are able to dynamically manipulate electromagnetic (EM) waves and realize innovative applications across diverse fields. However, conventional active metasurfaces are difficult to achieve continuous and dynamic control of absorptivity and reflectivity over a wide frequency band, which immensely restricts their application in weapon stealth and camouflage. This study presents what we believe to be a novel design that employs an absorbing active metasurface (AAM) to continuously and dynamically control the reflection amplitude, which is achieved by flexibly controlling the external voltage of PIN diodes across multiple layers. The experimental results demonstrate that the proposed AAM can achieve continuous and dynamic amplitude modulation within the frequency range of 2.0-15.5 GHz at normal incidence, and maintain angular insensitivity within the incidence angle range of 0°-50°. This inspiring design not only has excellent dynamic control capabilities for EM waves absorption and reflection, but also possesses the advantages of simple design, small thickness and easy fabrication, which has tremendous application potential in stealth weapons and other smart metadevices.