(a–d) The unit cells of coding elements “00”, “01”, “10”, and “11”, (e–h) the simulate 3D far-field scattering pattern at 15 GHz under normal LCP, RCP, x-polarized and y-polarized incident waves, respectively, (i) the sample photograph where the inset is the detailed picture of coding element “00”, (j) the specular reflections under normal x-polarized and y-polarized incident waves. From reference [92]. Reprinted with permission from IOP.