fundamentals electrical noise

7/29/2019 Fundamentals Electrical Noise

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Fundamentals of ElectricalNoise

byKurt Stern Jan 2004


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White NoiseWhite Noise

In 1928 Johnson and Nyquist ID the

Problem Nyquists TheoremP = KTB

P = Noise Band power in WattsT = Temp Degree Kelvin (T)K = Boltzmans Constant 1.38X10 -23

B = Bandwidth (Hertz)


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Excess Noise Ratio in dB

ENR=10Log((T/290)-1)

T in Kelvin is the temperature of a resistor


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Noise Equivalency Reference ChartNoise Equivalency Reference Chart


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Applications of Applications of Noise TechnologyNoise Technology

Measure Noise Figure Gain and Bandwidth Parameters Susceptibility to External Interference Jamming System Self Test


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Noise MeasurementsNoise Measurements

The Radiometer Noise Standards Calibration of Noise Standards

Errors in Noise Measurements


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Basic Switching RadiometerBasic Switching Radiometer


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Simplified AutomateRadiometer


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NBS Switching RadiometerNBS Switching Radiometer


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Commercial Switching RadiometerCommercial Switching Radiometer


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Commercial Switching RadiometerCommercial Switching Radiometer

(Specifications for the PRD 915(Specifications for the PRD 915 -- B Attenuation Calibrator)B Attenuation Calibrator)


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Noise Figure Measurements

Y Factor

Twice Power Measurements Automatic Measurements

Noise Figure to Temperature


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Y Factor


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Twice Power NF Measurement


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Noise Figure vs. Noise Temperature

Conversion Chart


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ENR Measurement VSWR Error


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Noise Source UUT VSWR Error


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Automatic Noise Figure MeterAutomatic Noise Figure Meter


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Noise Figure Equivalence Chart


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Applications by IndustryApplications by Industry

Military Electronics Manufacturing Communications


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Noise Standards

Characteristics

- Flat Power Spectrum- High Degree of Stability 3 Classes

- Noise Diodes- Gas-Discharge Tubes- Thermal Noise Sources


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Generation of Noise


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Thermal Noise Calculation


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Avalanche Noise Region


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Vacuum Diode Noise Source


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High Temperature Noise Standard


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Low Temperature Noise Standard


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Low Temperature Thermal

Conductivity


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Error Flow Diagram


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DUT Noise Temperature Errors


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USA-England Intercomparison


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USA-Sweden Intercomparison


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Noise AmplificationNoise Amplification

Bandwidth Power Crest Factor


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Crest Factor (CF)Crest Factor (CF)


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Gaussian Noise DistributionNoise Distribution

A lifi B d idth & P


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Amplifier Bandwidth & Power

Noise Power =Unit noise power X bandwidth

Consequently for some designs widerbandwidths may require a highercompression point amplifier

C i ti S t


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Communications Systems

Testing

White Noise Testing Bit Error Rate vs. Noise

hWhi N i T i


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White Noise TestingWhite Noise Testing

Whi N i T E iWhi N i T E i


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White Noise Test EquipmentWhite Noise Test Equipment

NoiseGenerator

Noise

Receiver


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ATM N i SATM N i S


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ATM Noise SourcesATM Noise Sources

(Z Model)(Z Model)

ATM N i SATM Noise So rce


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ATM Noise SourceATM Noise Source

(Y Model)(Y Model)


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Thank You

fundamentals electrical noise

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