Qun Yan Zhou, Si Ran Wang, Han Qing Yang, Jiayu Han, Lijie Wu, Jia Chen Wang, Jitong Ma, Hui Dong Li, Jun Yan Dai, Tie Jun Cui, Qiang Cheng
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.