# Spreadsheets/Programs

These programs and files are considered to be “freeware” and they may be used, modified, distributed, etc. without restriction^{1}. 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.