Space-time metallic metasurfaces for frequency conversion and beamforming

This study details a class of metal-based metasurfaces that periodically alternate their properties in both space and time. The authors' approach offers an alternative for simulating such metasurfaces, providing physical insight into the diffraction phenomenon. The analytical framework is based on the circuit equivalent of the physical structure, revealing important features such as scattering parameters, field profiles, diffraction angles, and the nature of space-time harmonics. The results of the study highlight the potential for these metasurfaces in beamformers or frequency mixers for wireless communication systems.