Multi-Channel Wireless Communication Based on Amplitude-Phase Reconfigurable Space-Coding Beamforming Metasurface

Reconfigurable metasurfaces have exhibited significant potential in wireless communication owing to their capacity to transmit information without relying on traditional complex radio frequency (RF) chain transmitters. Nonetheless, the majority of metasurface-based wireless communication systems modulate signals only in the time domain. Here, an amplitude-phase reconfigurable metasurface is proposed to establish a wireless communication system that can simultaneously transmit different messages to users by encoding digital signals within the spatial domain. By changing the bias voltages of varactors integrated in the meta-atom, the reconfigurable metasurface can achieve independent 3-bit phase and 1-bit amplitude coding. Through a beamforming methodology, the proposed metasurface generates diverse scattering beams with suppressed sidelobe levels, which not only enables multiple channels through space coding but also reduces signal leakage in undesired directions. Numerical simulations and experiments are carried out to verify the beamforming scheme, and a dual-channel wireless communication system is established. The results show that two distinct images can be simultaneously retrieved by two separate users, which demonstrates the dual-channel transmission capability of the wireless communication system. The proposed strategy opens up an avenue for implementing multi-channel wireless communication systems, which indicates its great potential in multiple-user collaborative wireless communication and radar systems. This work presents an innovative amplitude-phase reconfigurable metasurface designed to construct a robust multi-channel wireless communication framework. Notably, the signal is modulated in the spatial domain without involving time modulation. First, it generates desired scattering beams through beamforming to establish multiple channels. Second, the metasurface significantly curbs sidelobe level, thus mitigating signal leakage in unfavorable directions. image