Simplified digital lock-in amplifier algorithm

Leis, J. and Martin, P. and Buttsworth, D. (2012) Simplified digital lock-in amplifier algorithm. Electronics Letters, 48 (5). pp. 259-261. ISSN 0013-5194


The phase-sensitive or 'lock-in' amplifier is a fundamental tool in experimental physics, and is able to extract exceedingly small signals in the presence of noise. Recently, there has been some interest in portable or embedded lock-in amplifiers for instrumentation and sensing. One difficulty with digital lock-ins is the required degree of numerical precision. This letter presents a fast algorithm for combined phase-sensitive multiplication and filtering. It exploits symmetry to reduce the number of arithmetic operations, and is suitable for low-power embedded devices. As well as being computationally much simpler than a direct digital implementation, the results presented show that it yields a lower error in the estimation of the underlying signal amplitude.

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Item Type: Article (Commonwealth Reporting Category C)
Refereed: Yes
Item Status: Live Archive
Additional Information: Permanent restricted access to published version due to publisher copyright policy.
Faculty / Department / School: Historic - Faculty of Engineering and Surveying - Department of Electrical, Electronic and Computer Engineering
Date Deposited: 06 Aug 2012 09:11
Last Modified: 18 Jul 2014 05:12
Uncontrolled Keywords: digital instrumentation; measurement; digital filters; amplifiers; low-power electronics
Fields of Research : 09 Engineering > 0906 Electrical and Electronic Engineering > 090603 Industrial Electronics
09 Engineering > 0906 Electrical and Electronic Engineering > 090609 Signal Processing
09 Engineering > 0906 Electrical and Electronic Engineering > 090601 Circuits and Systems
Socio-Economic Objective: B Economic Development > 86 Manufacturing > 8616 Computer Hardware and Electronic Equipment > 861604 Integrated Systems
Identification Number or DOI: 10.1049/el.2012.0193

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