Wide-range lock-in amplifier

Patent · Tue Sep 17 04:00:00 EDT 1985

OSTI ID:5738635

McNeilly, D R

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.

• Assignee: The United States of America as represented by the United States Department of Energy
• Patent Number(s): US 4542346
• OSTI ID: 5738635
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
420800* -- Engineering-- Electronic Circuits & Devices-- (-1989)
ALTERNATING CURRENT
AMPLIFIERS
AMPLITUDES
COMPUTERS
CURRENTS
DESIGN
ELECTRIC CURRENTS
ELECTRIC FILTERS
ELECTROMAGNETIC RADIATION
ELECTRONIC CIRCUITS
ELECTRONIC EQUIPMENT
EQUIPMENT
FILTERS
FREQUENCY DEPENDENCE
FUNCTION GENERATORS
MICROELECTRONIC CIRCUITS
MICROPROCESSORS
PHASE SHIFT
PULSE CIRCUITS
PULSE GENERATORS
RADIATIONS
RADIOWAVE RADIATION
SIGNAL CONDITIONERS
SIGNAL CONDITIONING
SIGNAL-TO-NOISE RATIO
SIGNALS