Op. amps., quartz resonators, and noise: Fit the Driven Data Circuit


		PHYS 381/504: Op. amps., quartz resonators, and noise



	Introduction
	Johnson Noise
	Macroscopic Derivation
	Microscopic Derivation
	Install and Test the Optical Amplifier
	Install the Tuning Fork
	Welcome to LabView
	Tune out the Package Capacitance
	Gather Data
	Load the Driven Circuit Data
	Fit the Driven Circuit Data
	Find Circuit Characteristics from this Fit
	Analyze the Undriven Circuit from Characteristics
	Final Results
	References

	PHYS 381La HOME
	Classes Page

Andrew Pariser, December 2005
modified S.M., January 2006

© 2006 Yale University, New Haven, Connecticut 06520

Data Fitting

Fit the data, using a standard Lorentz curve (not what Groebr uses, but this works!)

Mathematica will not fit the constant c. We fix the value by taking the average height of the noise response off resonance.

$backgroundNoiseLevel = Mean[Table[Peak_V[[i, 2]], {i, 1, 400}]]$

Perform the fit, fixing f0 as the resonance frequency, and c as the background noise level.

LorentzFit =

{BestFitParameters

This is the function with the values obtained from the fit.

Observe the fit laid on top of the data.

ListPlotPeak

[Graphics:HTMLFiles/data_fitting_10.gif]

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