Design of 3-bit Multibeam Vortex Metasurface Based on Phase Encoding

We design a broadband and efficient vortex beam-generating metasurface by performing 3-bit encoding in the compensation phase. The angle of double beam deflection is calculated through the derivation of generalized Snell's law. The gradient phase and the vortex phase are added to obtain the final compensated phase. The simulation results show that the metasurface proposed achieves beam deflection that meets the matching requirements of the the expectation.