- Title
- Amplitude noise spectrum of a lock-in amplifier: application to microcantilever noise measurements
- Creator
- Ruppert, Micahel G.; Bartlett, Nathan J.; Yong, Yuen K.; Fleming, Andrew J.
- Relation
- Sensors and Actuators A: Physical Vol. 312, Issue 1 September 2020, no. 112092
- Publisher Link
- http://dx.doi.org/10.1016/j.sna.2020.112092
- Publisher
- Elsevier
- Resource Type
- journal article
- Date
- 2020
- Description
- The lock-in amplifier is a crucial component in many applications requiring high-resolution displacement sensing; it's purpose is to estimate the amplitude and phase of a periodic signal, potentially corrupted by noise, at a frequency determined by a reference signal. Where the noise can be approximated by a stationary Gaussian process, such as thermal force noise and electronic sensor noise, this article derives the amplitude noise spectral density of the lock-in-amplifier output. The proposed method is demonstrated by predicting the demodulated noise spectrum of a microcantilever for dynamic-mode atomic force microscopy to determine the cantilever on-resonance thermal noise, the cantilever tracking bandwidth and the electronic noise floor. The estimates are shown to closely match experimental results over a wide range of operating conditions.
- Subject
- lock-in amplifier; demodulation; atomic force microscopy; estimation; noise spectral density; thermal noise
- Identifier
- http://hdl.handle.net/1959.13/1426876
- Identifier
- uon:38483
- Identifier
- ISSN:0924-4247
- Rights
- © 2020. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/.
- Language
- eng
- Full Text
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