A Reconfigurable Cassegrain Metasurface for Near-field and Far-field Pattern Manipulation

Reconfigurable metasurfaces have become a research hotspot in electromagnetic manipulation. However, current microwave reconfigurable metasurfaces are mostly reflective and only feature a low 1-bit phase control resolution. To address this issue, a Cassegrain metasurface with 2-bit phase manipulation capability is proposed in this paper. The metasurface consists of a primary reflector for polarization conversion and a secondary reflector for dynamic phase control, with an overall profile of approximately one operating wavelength. The simulation results show that the metasurface can realize real-time near-field focusing of electromagnetic waves as well as real-time manipulation of far-field single and multiple beams, exhibiting potential applications in wireless communication, wireless sensing and wireless power transfer.