Reconfigurable metasurface with flexible transmission-reflection switching for full-space beam shaping

Abstract

Beam shaping is essential for improving the performance of wireless communication, radar detection, and electromagnetic sensing systems, yet existing phased-array and lens architectures remain bulky, costly, and power-hungry due to densely integrated active components. Metasurfaces provide a compact and design-flexible alternative; however, most reported implementations operate solely in either transmission or reflection mode, limiting their electromagnetic manipulation capabilities. This work proposes a reconfigurable metasurface incorporating PIN diodes that can flexibly and dynamically switch between transmission and reflection modes. Under 12.47 GHz excitation, when the PIN diodes are in the ON–ON or OFF–OFF state, the unit cells exhibit high transmission with a phase difference of approximately 180°, enabling a 1-bit transmissive digital coding metasurface. Conversely, when the diodes are in the ON–OFF or OFF–ON state, the unit cells achieve high reflection with a reflection phase difference of 180°, enabling a 1-bit reflective digital coding metasurface. By flexibly configuring the ON and OFF states of the PIN diodes and applying different coding sequences, the metasurface can dynamically switch between transmissive and reflective modes while enabling full-space beam shaping. The proposed metasurface features high flexibility and full-space coverage capability, showing broad application prospects in next-generation intelligent wireless communication and radio-frequency sensing systems.