Spectrum information of the PB metasurface particles under normal incidence of LCP and RCP waves. (a) The reflection magnitude for cross-polarization with different rotation angle β. (b) The reflection phase for cross-polarization with different rotation angle β. (c) The 1-bit, 2-bit, and 3-bit coding metasurface unit cells and their corresponding PB phases.(d) The basic parameters of eight coding elements for the 1-bit, 2-bit, and 3-bit coding metasurfaces.