Spreadsheets/Programs
These programs and files are considered to be
"freeware" and they may be used, modified, distributed, etc.
without restriction1. No claims or guarantees
are made regarding their suitability for use; I have found mistakes in the past
and there could easily be more. Note: You may need to activate the "analysis
tool pack" (under "add-ins" in the "Tools" menu) for some of
these spreadsheets. Visual Basic programs require vbrun300.dll in the windows/system
directory.
Vibration Induced Phase Noise
Acceleration sensitivity is a vector quantity which may be expressed by a magnitude and
direction or as the summation of three orthogonal vectors usually aligned with the sides
of the oscillator's case. The induced phase noise may be calculated from the following
equation:
L(f) = 20 log ((acceleration sensitivity x acceleration x oscillator frequency) / (2 x
vibration frequency)),
where the acceleration is the g level for sine wave vibrations or the square-root of
twice the power spectral density in a one hertz bandwidth for random vibration.
The spreadsheets below perform this calculation for random vibration. (They may be used
to calculate the sideband due to a sine wave by entering one-half the squared vibration
level into the vibration level g^2/Hz cell. For example, if the sinewave
amplitude is 9 grms, enter 81/2 or 40.5 ) The first section of the spreadsheet calculates the effect of a single
degree-of-freedom vibration isolation system given the natural frequency and the damping
factor. The second graph shows the phase noise of an oscillator with a specified
acceleration sensitivity mounted on the vibration damping system. The vibration isolation
system may be removed from the calculation by entering a very high natural resonance
frequency (1E6) so that no vibration damping occurs over the frequency span shown.
Vibration profiles may be entered by changing a scaling factor, either increasing or
decreasing the level from some nominal point. The frequency points may be changed or
additional columns may be added.
(Note: these files were modified so that the vibration profile coefficient modifies the
vibration power spectral density (g2/Hz) instead of the amplitude (g/Root-Hz).
PLL Calculators
This spreadsheet calculates the bandwidth and damping factor for a
type-two PLL. The user enters the VCO tuning sensitivity, the loop components, and the
phase detector sensitivity.
This spreadsheet calculates the phase noise of a PLL based upon the noise
of the reference and the VCO and the loop characteristics. This spreadsheet includes the
calculator above. Remember to scale the noise of the reference to the VCO output frequency
(20 log N).
Allan Variance from Phase Noise
This spreadsheet calculates the Allan Variance from supplied phase noise
intercepts. Total RMS jitter over the specified bandwidth is also calculated (as of March
23, 1998).
Visit David W. Allan's website, Allan's Time - especially The Allan Variance.
Phase Noise Due to E.T. Noise
Calculate phase noise caused by noise voltage on the electrical tuning line.
Phase Noise Triangulation
Basic Program calculates individual phase noise from three measurements of
three sources. (Requires vbrun300.dll in the windows/system directory.)
Other spreadsheet formats will be added here, upon request.
1 Plagiarism and fraud are always wrong,
however.
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