Scattering control via STC digital metasurfaces. Reproduced from [110
]. (a) An optimized 2D space-coding matrix and a 3D STC matrix for RCS reduction. (b) The corresponding scattering patterns at various frequencies. (c) Maxima of the scattering patterns from the -50th
to the +50th
harmonic frequencies, corresponding to the 3D STC matrix in (a).