Real-time holographic imaging programmable metasurfaces based on hardware accelerator computation

—Dynamic control of electromagnetic waves can be achieved using programmable metasurfaces. We propose a 1-bit real-time holographic programmable metasurface based on hardware acceleration. The field-programmable gate array (FPGA) is used as the hardware accelerator to accelerate the computation of the backpropagation algorithm, obtaining the encoding pattern of the programmable metasurface unit structure. By controlling the on/off state of diodes, we encode the programmable metasurface and achieve real-time hologram calculation at a rate of 13 frames per second. The proposed programmable metasurface can achieve a phase variation of 180° in its unit structure. Furthermore, we experimentally fabricated and tested the designed programmable metasurface using near-field scanning. When the incident electromagnetic wave frequency was 7.66 GHz, the programmable metasurface successfully realized real-time holographic imaging function, with theoretical and experimental results being consistent.