Integrated Clock with Low Phase Noise and Wide bandwidth

Background

LOs are indispensable for advanced electronic systems with different specs for different applications.  The key specs are low phase noise, wide bandwidth and small form factor. Opto-electronic oscillator (OEO) and dielectric resonator oscillator (DRO) delivers ultra clean LOs due to extremely high Q components, such as optic fibers and sapphire resonators. However, these approaches have very limited tuning ranges and large size, limiting their applications. In contrast, integrated semiconductor LOs show great promise for a wide range of applications due to the small factor and configurability. However, their low Q components limit phase noise, which limits the ultimate achievable system performance.

Our Approach

To address low phase noise issue in integrated semiconductor LOs, we propose the phase noise filter technique which is based on a delay line frequency discriminator, to suppress the LO phase noise while supporting wide bandwidth. The first step is to design high sensitivity phase noise measurement (PNM) circuit, which is shown in the Figure. The PNM mainly consists of divider, on-chip passive voltage controlled delay line (VCDL), off-chip SAW filter, PD, CP and analog baseband (ABB), which includes a variable gain amplifier (VGA) and a low pass filter (LPF). The advantages of this approach include: (1) support wide bandwidth in contrast to high Q resonator based frequency discriminator; (2) resilient to amplitude and coupling noises comparing to mixer based phase detection. This PNM demonstrates the sensitivity of 10 GHz clock with -138.6 dBc/Hz @ 1 MHz offset.

Publication

  1. S. Hao, J. Li, T. Hu, V. Squitieri, Y. Tang, Z. Xu and Q. Jane Gu, “An Active Circulator Based Delay Line,” IEEE MWCL, July 2019
  2. S. Hao, T. Hu, and Q. J. Gu, “Time-Amplifier Enhanced Phase Noise Filter,” IEEE MWCL July, 2018
  3. T. Hu, S. Hao, and Q. J. Gu, “A 10 GHz Digital Phase Noise Filter with 14 dB Noise Suppression and -127 dBc-Hz Noise Sensitivity at 1 MHz Offset,” RFIC 2018 Student Paper Finalist
  4. S. Hao, T. Hu, and Q. J. Gu, “10 GHz inverter-type-time-amplifier based phase noise filter with -133 dBc/Hz phase noise sensitivity,” IEL, April 2018
  5. S. Hao, T. Hu, and Q. J. Gu, “Frequency Discriminator based Phase Noise Filter for High Fidelity Clock,” IEEE International Symposium on Radio-Frequency Integration Technology RFIT2017, Invited Paper
  6. T. Hu, S. Hao, and Q. J. Gu, “Analysis and Design of Bang-Bang PD based Phase Noise Filter,” IEEE Transactions on Circuits and Systems I, October 2017
  7. T. Hu, S. Hao, B. Yu, J. Li, Y. Ye and Q. J. Gu, “A Bang-Bang PD based Phase Noise Filter with 23 dB Noise Suppression,” IEEE International Microwave Symposium IMS2017
  8. S. Hao, T. Hu, and Q. J. Gu, “A 10 GHz Delay Line Frequency Discriminator and PD/CP based CMOS Phase Noise Measurement Circuit”, IEEE Transactions on Microwave Theory and Techniques, May 2017
  9. S. Hao, T. Hu, and Q. J. Gu, “A CMOS Phase Noise Filter with Passive Delay Line and PD/CP based Frequency Discriminator,” IEEE Transactions on Microwave Theory and Techniques, November 2017
  10. S. Hao, Q. J. Gu, “A 10 GHz Phase Noise Filter with 10.6 dB Phase Noise Suppression and -116 dBc/Hz Sensitivity at 1 MHz Offset,” IEEE International Microwave Symposium 2016, Best Student Paper Award, 2nd Place Winner
  11. S. Hao, T. Hu, and Q. J. Gu, “Phase Noise Improvement for Array Systems,” IEEE International Microwave Symposium 2016
  12. T. Hu, S. Hao, Q. J. Gu, “A 9.95 – 10.05 GHz Bang-Bang PD based Phase Noise Filter with 10 dB Noise Suppression,” IEEE International Symposium on Radio-Frequency Integration Technology(RFIT) 2016, Best Student Paper Award
  13. S. Hao, T. Hu, Q. J. Gu, “A 10 GHz Delay Line Frequency Discriminator and PD/CP based CMOS Phase Noise Measurement Circuit with -138.6 dBc/Hz Sensitivity at 1 MHz Offset,” accepted by 2015 IEEE Radio Frequency Integrated Circuits Symposium (RFIC)
  14. S. Hao and Q. J. Gu, “A Fourth Order Tunable Capacitor Coupled Microstrip Resonator Band Pass Filter,”  2015 IEEE Radio Wireless Week

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