Space-Time Decoupled Information Metasurface

Information metasurface is a type of metasurface device capable of rapidly altering its EM characteristics to generate specific information. Past research presents various strategies for embedding information into ambient EM waves through the superposition of each unit's quantified properties. Despite their capabilities, these approaches alone are insufficient for independently managing the creation of information and the allocation of spatial energy. Here, we propose a general theory of space-time decoupled metasurface (STD-Metasurface) to obtain the completely independent manipulation of information generating and spatial filtering. As proof-of-concept demonstration, we design a single-diode small-signal-modulation based prototype, capable of generating precise arbitrary waveforms while maintaining unaltered beam patterns. We exhibit how the superiority of the STD-Metasurface enhance its practicality and facilitate its application as a reconfigurable backscatter transmitter and an dynamic Doppler-spoofing reflection tag.