Metasurface-Based Direct Digital Communication With Out-of-Band Radiation Suppression

This letter proposes a scheme of metasurface-based digital communication with out-of-band (OOB) radiation suppression. The existing systems' uniform-amplitude radio frequency feeding leads to OOB signal during the transition between different phase states. This results in undesired signal leakage and interference. In the proposed scheme, the amplitude of the feeding RF signal is manipulated and it is synchronous with the baseband symbol waveform. Consequently, the OOB radiation is reduced and the suppression performance can be adjusted by changing the amplitude function. Experimental results demonstrate that the power radiation outside the target frequency band is suppressed by about 10 dB while the symbol recovery is nearly unaffected. Therefore, the radiation and transmission performance of the system is improved, which provides more potential for metasurface-based communication in the future.