RF and microwave fractional differentiator based on photonics

Mengxi Tan, Xingyuan Xu, Bill Corcoran, Jiayang Wu, Andreas Boes, Thach G. Nguyen, Sai T. Chu, Brent E. Little, Roberto Morandotti, Arnan Mitchell, David J. Moss

Research output: Contribution to journalArticleResearchpeer-review

28 Citations (Scopus)


We report a photonic radio frequency (RF) fractional differentiator based on an integrated Kerr micro-comb source. The micro-comb source has a free spectral range (FSR) of 49 GHz, generating a large number of comb lines that serve as a high-performance multi-wavelength source for the differentiator. By programming and shaping the comb lines according to calculated tap weights, arbitrary fractional orders ranging from 0.15 to 0.90 are achieved over a broad RF operation bandwidth of 15.49 GHz. We experimentally characterize the frequency-domain RF amplitude and phase response as well as the temporal response with a Gaussian pulse input. The experimental results show good agreement with theory, confirming the effectiveness of our approach towards high-performance fractional differentiators featuring broad processing bandwidth, high reconfigurability, and potentially reduced sized and cost.

Original languageEnglish
Pages (from-to)2767-2771
Number of pages5
JournalIEEE Transactions on Circuits and Systems II: Express Briefs
Issue number11
Publication statusPublished - Nov 2020


  • Fractional differentiator
  • kerr micro-comb
  • RF signal processing

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