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Phase Noise Metrology Group

NIST's Phase Noise Metrology Group has the world's most advanced measurement and calibration facilities for characterizing noise components in oscillators and frequency synthesizers. It engages in many activities to determine the cause of various kinds of noise for the purpose of isolating and reducing it, ultimately leading to improved components, instruments and techniques that are often necessary for new applications.

Noise, present everywhere, causes a signal source to deviate from its ideal performance. It introduces time-dependent, random fluctuations in the frequency, phase and amplitude of a signal. These fluctuations due to noise manifest themselves as frequency modulation (FM), phase modulation (PM) and amplitude modulation (AM) of the ideal carrier. The spectral purity and frequency stability of a signal are characterized in terms of these modulation noise types. 

The goals of NIST’s Phase Noise Metrology Group are to: (1) support high-precision noise measurements, (2) contribute to fundamental improvements in spectral purity of oscillators and frequency synthesizers, and (3) provide certified state-of-the-art PM and AM noise measurement capabilities to National Measurement Institutes (NMIs), US military, industrial and commercial organizations.

Projects and Programs


30 GHz regenerative frequency divide-by-3

Archita Hati, Marco Pomponio, Connor Humiston, John Lettang, Craig Nelson
We report the performance of a 30 GHz to 10 GHz regenerative frequency divider. The proposed divider design incorporates the conventional Miller regenerative


  1. V. Gerginov, Two-Photon Optical Frequency Reference with Active AC Stark Shift Cancellation, Provisional Patent Application # 62,629,800
  2. A. Hati, C.W. Nelson, D.A. Howe, Phase Modulation Noise Reducer, United States, Patent # 10,050,608.
  3. D.A. Howe, A. Sen Gupta, C.W. Nelson, and F.L. Walls, High Spectral Purity Microwave Oscillator Using Air-Dielectric Cavity, United States Patent # 7,075,378
  4. F.L. Walls, Calibration System for Determining the Accuracy of Phase Modulation and Amplitude Modulation Noise Measurement Apparatus, United States Patent # 5,172,064
  5. F.L. Walls, Frequency Calibration Standard Using a Wide Band Phase Modulator, United States Patent # 5,101,506
  6. F.L. Walls, Method and Apparatus for Wide Band Phase Modulation, United States Patent # 4,968,908
  7. F.L. Walls and J.R. Vig, Acceleration Insensitive Oscillator, United States Patent # 4,575,690


2018 IEEE Fellow - David A. Howe

David A. Howe, NIST and Colorado University Professional Research Advisor, from Boulder, Colorado, USA has been named an IEEE Fellow. He is

Job Openings

Our group has periodic openings for Postdoctoral Fellows, Visiting Scientists, and Graduate Students. Please contact us for more information.


Group Leader

Calibration Leader