Fig. 5
RCS reductions via space-time-coding metasurfaces. a, b Metasurfaces with uniform and chessboard-like space-coding distributions, respectively. c 3D space-time-coding matrix obtained by applying the time-coding sequence “10” to the chessboard-like space coding. d Metasurface with an optimized space-coding distribution. e 3D space-time-coding matrix obtained by applying the random time-coding sequence “10011010” to the space coding in panel (d). f, g 2D scattering patterns pertaining to the metasurfaces in panels (a, b), respectively. h 2D scattering patterns pertaining to the space-time-coding digital metasurface in panel (c) at different harmonic frequencies. Note that this time-coding results in the generation of odd harmonics only. i 2D scattering patterns of the metasurface in panel (d). j 2D scattering patterns pertaining to the space-time-coding digital metasurface in panel (e) at different harmonic frequencies
