Space‐Time‐Frequency Information Metasurface and Its Application in Electromagnetic Environment Sensing

The advancement of 6G communications, Internet of Things, and electronic warfare systems toward higher frequencies, wider bandwidths, and multi-scenario cooperation has imposed increasingly stringent demands on real-time and high-precision electromagnetic field sensing. However, the efficiency-complexity trade-off persists as a critical bottleneck for conventional sensing approaches in the space, time and space-time domains. To address this problem, we propose a space-time-frequency information metasurface and investigate its applications in electromagnetic environment sensing. By incorporating differentiated frequency-shift digital coding into meta-atoms, different meta-atoms will modulate distinct characteristic frequencies independently, resulting in a space-time-frequency coding strategy. The joint coding strategy enables efficient decoupling and parallel extraction of atom-level electromagnetic signals in frequency domain under a single radio-frequency reception channel, significantly reducing the system complexity and hardware costs. This method extends the modulation dimensions of information metasurface to the space-time-frequency coding, and may pave a new pathway for high-dimensional electromagnetic signal processing and sensing systems.