Wide-range lock-in amplifier

Patent · Tue Jan 01 04:00:00 EST 1985

OSTI ID:865599

McNeilly, David R ^[1]

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1. Maryville, TN

A lock-in amplifier is provided which allows detection of a signal buried in noise without preprocessing of the input signal. An analog signal multiplier is used to obtain a dc output which is the product of the signal being detected and a high-purity sine wave signal. A reference signal of a known selectable frequency is applied to a sine-wave generator to generate the sine wave of the same frequency. The sine wave is applied to a multiplier through a phase shift arrangement to allow the detection of both amplitude of the detected signal and the phases relative to the reference signal. The multiplier output is filtered by a low-pass filter to eliminate unwanted frequency components from the output signal.

• Research Organization: Oak Ridge National Laboratory (ORNL), Oak Ridge, TN
• DOE Contract Number: W-7405-ENG-26
• Assignee: United States of America as represented by United States (Washington, DC)
• Patent Number(s): US 4542346
• OSTI ID: 865599
• Country of Publication: United States
• Language: English

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/327/331/
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