High level white noise generator

Patent · Tue Nov 20 04:00:00 EST 1979

OSTI ID:5416387

Borkowski, C J; Blalock, T V

A wide band, stable, random noise source with a high and well-defined output power spectral density is provided which may be used for accurate calibration of Johnson Noise Power Thermometers (JNPT) and other applications requiring a stable, wide band, well-defined noise power spectral density. The noise source is based on the fact that the open-circuit thermal noise voltage of a feedback resistor, connecting the output to the input of a special inverting amplifier, is available at the amplifier output from an equivalent low output impedance caused by the feedback mechanism. The noise power spectral density level at the noise source output is equivalent to the density of the open-circuit thermal noise or a 100 ohm resistor at a temperature of approximately 64,000 Kelvins. The noise source has an output power spectral density that is flat to within 0.1% (0.0043 db) in the frequency range of from 1 KHz to 100 KHz which brackets typical passbands of the signal-processing channels of JNPT's. Two embodiments, one of higher accuracy that is suitable for use as a standards instrument and another that is particularly adapted for ambient temperature operation, are illustrated in this application.

• Assignee: Dept. of Energy
• Patent Number(s): US 4175258
• OSTI ID: 5416387
• Country of Publication: United States
• Language: English

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47 OTHER INSTRUMENTATION
AMPLIFIERS
CALIBRATION
DESIGN
DIAGRAMS
DIGITAL SYSTEMS
ELECTRICAL EQUIPMENT
ELECTRONIC EQUIPMENT
EQUIPMENT
FEEDBACK
MEASURING INSTRUMENTS
MONITORING
NOISE
REACTOR NOISE
RESISTORS
THERMOMETERS