Planar efficient metasurface for vortex beam generating and converging in microwave region
In this paper, a single-layer transmission-type metasurface is proposed to generate vortex beams and converge the beam in microwave region. Utilizing the abrupt phase changes introduced by the unit cells, the required phase differences accumulated along the propagation path in conventional optical lens can be easily achieved, resulting in a planar structure of the proposed microwave lens. The results show that our design works efficiently at the operation frequency.