Reconfigurable 2-bit Digital Coding Metasurfaces in a non-contact way

In this paper, we propose and design an optically reconfigurable 2-bit digital coding metasurface in microwave band. The embedded two varactors in the digital element are controlled by a photodiode module, and hence the states of the designed digital element can be remotely tuned by the intensity of illuminating light. Using such elements to compose reflective digital coding metasurfaces, dynamically reconfigurable radiation beams are obtained in a non-contact tuning way. Simulation results verify that the proposed digital coding metasurface is capable of generating the desired wave controlling, beam deflection and beam splitting.