Abstract
Real-time spectrum sensing (RT-SS) is an essential technology for the upcoming sixth-generation (6G) networks, enabling dynamic spectrum management to support emerging integrated sensing and communication (ISAC) applications. However, conventional electronic and photonic RT-SS solutions face challenges in achieving ultrawide measurement range, compact size, and low latency, simultaneously. Here, we demonstrate an integrated photonic RT-SS system covering microwave to sub-terahertz bands on a thin-film lithium niobate (TFLN) platform. The TFLN chip integrates a broadband electro-optic (EO) modulator for signal loading, an EO microring filter bank for high-speed parallel frequency-to-time mapping, and an EO comb for channel referencing. The system achieves an analysis bandwidth of 57.5 GHz and measurable frequency up to 120 GHz, at a low latency of < 110 ns. The RT-SS system is further validated through a proof-of-concept ISAC demonstration, where a radar adaptively accesses underutilized spectral regions for high-quality ranging under dynamic communication interferences. Our work provides a compact solution for high-efficiency spectrum management in 6G ISAC networks.
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Data availability
The data generated in this study has been deposited in the Zenodo at (https://doi.org/10.5281/zenodo.18731695).
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Acknowledgements
This work is supported by the Research Grants Council, University Grants Committee (STG3_E-104-25-N, C.W., CityU 11204022, C.W., CityU 11204523, C.W., C1002-22Y, C.W., STG3/E-704/23-N, C.W., CityU 11212721, C.W., CityU 11213125, C.W., and JRFS2526-1S01, H.F.), Croucher Foundation (9509005, C.W.), City University of Hong Kong (9610682, C.W.). We thank W.-H. Wong and K. Shum at CityU for their help in device fabrication and measurement. We thank the technical support of C. F. Yeung, S. Y. Lao, C. W. Lai and L. Ho at HKUST, Nanosystem Fabrication Facility (NFF), for the stepper lithography and PECVD process.
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Y.T., H.F. and C.W. conceived the idea, with the discussions from H.S. and X.W. Y.T. proposed the system architecture and designed the devices. H.F., Y.W. and Z.C. fabricated the devices. Y.T. and H.F. carried out the experimental measurements and data analysis, with the assistance of X.X., Y.S.Z., Y.W.Z., T.G., and Z.T. The adaptive spectrum allocation algorithm was proposed by Y.F., X.Y. and J.X. The spectrogram data analysis and the imaging simulation of the ISAC demonstration was implemented by Y.F., with the guidance from X.Y. The paper was prepared by Y.T. and H.F., with contributions from all authors. C.W. supervised the project.
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H.F., Z.C. and C.W. are involved in developing lithium niobate technologies at RhinoptiX Technology Ltd. The remaining authors declare no competing interests.
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Nature Communications thanks Jose Azana, who co-reviewed with Xinyi Zhu; and the other, anonymous, reviewers for their contribution to the peer review of this work. A peer review file is available.
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Tao, Y., Feng, H., Fang, Y. et al. Integrated photonic ultrawideband real-time spectrum sensing for 6G wireless networks. Nat Commun (2026). https://doi.org/10.1038/s41467-026-70389-0
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DOI: https://doi.org/10.1038/s41467-026-70389-0
