Related Experiment Video
Updated: Apr 29, 2026

Fabrication and Characterization of High-Q Silicon Nitride Membrane Resonators
Published on: August 8, 2025
Eliminating 1/f noise in oscillators
1Department of Physics, California Institute of Technology, Pasadena, California 91125, USA.
Abstract:
We study 1/f and narrow-bandwidth noise in precision oscillators based on high-quality factor resonators and feedback. The dynamics of such an oscillator are well described by two variables, an amplitude and a phase. In this description we show that low-frequency feedback noise is represented by a single noise vector in phase space. The implication of this is that 1/f and narrow-bandwidth noise can be eliminated by tuning controllable parameters, such as the feedback phase. We present parameter values for which the noise is eliminated and provide specific examples of noise sources for further illustration.
Related Concept Videos
Oscillations In An LC Circuit
Design Example: Underdamped Parallel RLC Circuit
Starting with a fixed...
RLC Circuit as a Damped Oscillator
Consider a series RLC circuit. Here, the presence of resistance in the circuit leads to energy loss due to joule heating in the resistance. Therefore, the total electromagnetic energy in the circuit is no longer constant and decreases with time. Since the magnitude of charge, current, and potential difference continuously decreases, their oscillations are said to be damped. This is...
Cut-off Frequency of BJT
Alpha Cut-Off Frequency: Pertinent to the common-base configuration, the alpha cut-off frequency defines the upper-frequency limit at which the current gain, alpha, remains stable. As...
Forced Oscillations
Biasing of FET
In an N-channel JFET, the structure consists of N-type material forming the channel on a P-type substrate, with the...

