Transparent and Flexible Chessboard Metasurface Based on Optimized Multielement Phase Cancellation for Wideband RCS Reduction

An optically transparent chessboard metasurface is proposed to achieve wideband radar cross section (RCS) reduction in this paper. The metasurface is a single-layer sandwich structure composed of indium-tin-oxide (ITO) square patches with different sizes and surface resistances, polyethylene terephthalate (PET) substrate, and ITO backplane from the top downwards. Based on optimized multielement phase cancellation (OMEPC) to select the sizes and surface resistances of ITO patches, the proposed metasurface can achieve the 10 dB RCS reduction from 10.1 to 26.4 GHz with a relative bandwidth of 89% under normal incidence. The total thickness of the metasurface is 2 mm, which makes it highly flexible. When there is a slight cylindrical curvature on the metasurface and the curvature angle is less than 30 degrees, an approximate 10 dB RCS reduction can still be achieved in the frequency range of 10-25 GHz under normal incidence. When the oblique incidence angle is less than 45(degrees), the proposed metasurface also exhibits nearly 10 dB RCS reduction at the specular direction in the frequency range of 10-25 GHz. Finally, a sample is fabricated and measured, and the experimental results are in good agreement with the simulation results.