Design of dual-function metasurface based on beam polarization characteristics

Abstract In order to solve the problem of mono-working frequency and monofunction of traditional metasurface, a design approach for realizing dual-band dual-function metasurface based on beam polarization characteristics is proposed. Based on the principle of the dipole that it can only induce the parallel electric field while maintaining unsensitive to vertical electric field, a T shaped unit structure consist of two dipole is designed, which could realize the flexible control on reflecting phase and operating frequency independently. According to the generalized Snell's law and the spiral phase factor required to generate orbital angular momentum (OAM) electromagnetic waves, the two dipoles are respectively coded to construct 3-bit metasurfaces. Numerical simulation and measured results show that the metasurface designed according to the above method has beam deflection function at 18 GHz when the x-polarized wave is incident, and the vortex electromagnetic wave can be generated at 32 GHz when the y-polarized wave is incident, which proves the correctness and effectiveness of the proposed method. The proposed design method can be extended to the terahertz band or even the optical band. The metasurface designed according to this method has potential application value in multiple input multiple output (MIMO) communication systems.