RCS Reduction on Patterned Graphene-Based Transparent Flexible Metasurface Absorber

A metasurface absorber consisting of patterned graphene sandwich structure, transparent flexible polyvinyl chloride (PVC) dielectric layer, and indium tin oxide (ITO) bottom plate is proposed in microwave band. The graphene layer is patterned as periodic strip bands with the same rectangular holes. The radar cross section (RCS) characteristics are studied by simulation and experiment. The results indicate that the proposed transparent flexible metasurface shows more than 10 dB RCS reduction in dual band, wideband, and single band when the sheet resistance (
$R_{s}$
) of graphene is 70, 240, and
$350~\Omega $
/sq, respectively. For
$R_{s} = 240\,\,\Omega $
/sq, RCS reduction in the conformal case is better than 10 dB in 8.52–16.98 GHz, and corresponding relative bandwidth is 66.35%. The regulation characteristics are attributed to the strong interference at the resonant frequency or in the broadband. It effectively captures the incident electromagnetic (EM) waves in the metasurface, and the incident wave energies are dissipated with high ohmic loss. Moreover, the RCS suppression ability of the conformal metasurface becomes better with the increase of curvature radius when the metasurface size is fixed. The proposed metasurface initiates a new way for research and development of multifunctional metasurface devices, which has important application in EM stealth in microwave band.