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Title: High level white noise generator

Abstract

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.

Inventors:
 [1];  [2]
  1. (Oak Ridge, TN)
  2. (Knoxville, TN)
Publication Date:
Research Org.:
Oak Ridge National Laboratory (ORNL), Oak Ridge, TN
OSTI Identifier:
863455
Patent Number(s):
US 4175258
Assignee:
United States of America as represented by United States (Washington, DC) ORNL
DOE Contract Number:  
W-7405-ENG-26
Resource Type:
Patent
Country of Publication:
United States
Language:
English
Subject:
level; white; noise; generator; wide; band; stable; random; source; well-defined; output; power; spectral; density; provided; accurate; calibration; johnson; thermometers; jnpt; applications; requiring; based; open-circuit; thermal; voltage; feedback; resistor; connecting; input; special; inverting; amplifier; available; equivalent; impedance; caused; mechanism; 100; ohm; temperature; approximately; 64; 000; kelvins; flat; 0043; db; frequency; range; khz; brackets; typical; passbands; signal-processing; channels; embodiments; accuracy; suitable; standards; instrument; particularly; adapted; ambient; operation; illustrated; application; spectral density; wide band; noise source; johnson noise; temperature operation; applications requiring; particularly adapted; ambient temperature; frequency range; output power; amplifier output; output impedance; random noise; feedback resistor; source output; density level; white noise; ohm resistor; processing channels; accurate calibration; /331/

Citation Formats

Borkowski, Casimer J., and Blalock, Theron V. High level white noise generator. United States: N. p., 1979. Web.
Borkowski, Casimer J., & Blalock, Theron V. High level white noise generator. United States.
Borkowski, Casimer J., and Blalock, Theron V. Mon . "High level white noise generator". United States. https://www.osti.gov/servlets/purl/863455.
@article{osti_863455,
title = {High level white noise generator},
author = {Borkowski, Casimer J. and Blalock, Theron V.},
abstractNote = {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.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {1979},
month = {1}
}

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