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