Space-Time Metallic Metasurface for Frequency Conversion and Beamforming Moreno Rodríguez, Salvador Alex Amor, Antonio Padilla De La Torre, Pablo Valenzuela Valdés, Juan Francisco Molero Jiménez, Carlos beam control frequency conversion optoelectronics wave scattering metagratings metasurfaces wireless communication networks finite-difference time-domain method This work has been supported by Grant No. TED2021-129938B-I00 funded by MCIN/AEI/10.13039/501100011033 and by the European Union NextGenerationEU/PRTR. It has also been supported by Grants No. PID2020-112545RB-C54, No. PDC2022-133900-100, and No. PDC2023-145862-I00, funded by MCIN/AEI/10.13039/501100011033 and by the European Union NextGenerationEU/PRTR. It is also part of Grant No. IJC2020-043599-I funded by MICIU/AEI/10.13039/501100011033 and by European Union NextGenerationEU/PRTR. This paper details a class of metal-based space-time metasurfaces for application in wireless com- munications scenarios. Concretely, we describe space-time metasurfaces that periodically alternate their properties in time between three spatial states: “air,” “conductor,” and “grating.” We analyze the physics of these metastructures via a computationally efficient analytical technique based on the use of Floquet-Bloch series, integral equations, and circuit models. By doing so, we reveal features of these spatiotemporal metasurfaces: scattering parameters, field profiles, diffraction angles, and the nature of the space-time harmonics. The results, corroborated with a self-implemented numerical finite-difference time-domain approach, show the potential application of these space-time metasurfaces as beamformers acting in reflection, in transmission or both. The amplitude and direction of the diffracted orders can be electroni- cally controlled with the parameters of the metasurface. Moreover, the intrinsic ability of time-modulated diffractive metasurfaces to mix and multiply frequencies is tested. We show how two different modulations can lead to the same diffraction angle but with different mixed output frequencies. 2024-12-11T10:39:07Z 2024-12-11T10:39:07Z 2024-06-07 journal article Salvador Moreno-Rodríguez et al. “Space-time Metallic Metasurfaces for Frequency Conversion and Beamforming”. Physical Review Applied, vol. 21, no. 6, 064018, 2024. https://doi.org/10.1103/PhysRevApplied.21.064018 https://hdl.handle.net/10481/97893 10.1103/PhysRevApplied.21.064018 eng http://creativecommons.org/licenses/by-nc-nd/4.0/ open access Attribution-NonCommercial-NoDerivatives 4.0 Internacional American Physical Society