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Low g–sensitivity Crystals
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G–sensitivity is defined as a change in frequency resulting from an acceleration force applied to an oscillator. It is often expressed in terms of ppb/g. How does this affect performance? When an oscillator is used in an environment conducive to vibration, the frequency of the vibration will modulate the carrier frequency degrading the phase noise performance of the oscillator. This phenomenon is similar for both random and sine vibration and is also very deterministic meaning the magnitude of the induced phase noise degradation can be calculated if the g-sensitivity of the oscillator is known. John Vig has written an excellent tutorial on quartz crystals and resonator stabilities [1]. Please follow the link to an excerpt from John's tutorial which will provide a more detailed description of g–sensitivity and the equations for calculating the resulting phase noise in random and sine vibration environments.

John Vig Tutorial
[1] J.R. Vig, "Quartz Crystal Resonators and Oscillators – For Frequency Control and Timing Applications – A Tutorial", January 2004

View our g–sensitivity product portfolio

Vectron's Quad Relief Mount (QRM)

Applications: Mobile Communications, Military Communications, Munitions, Industrial

Standard QRM: <0.2ppb/g Total Gamma (all axes)
Best Specification: <0.1ppb/g Total Gamma (all axes)
100% tested under vibration

More technical info on the QRM:
The Effect of contour concentricity on the acceleration

Photo of a CAD drawing of Quad Relief Mount crystal Photo of a Quad Relief Mount Crystal

Low g–sensitivity TO–8's

By Design (no testing): <0.35ppb/g Total Gamma (all axes)
With Screening: <0.2ppb/g Total Gamma (all axes)

Per Axis Basis
By Design (no testing): <0.25ppb/g Total Gamma (all axes)
Best Specification (100% test): <0.2ppb/g
100% tested under vibration

Photo of a open TO-8 Crystal Package Photo of a open TO-8 Crystal Package

Design, Process & Metrology Capabilities

Measurement Method:
Vectron has developed sophisticated simulation tools to allow us to optimize our designs for the best possible g–sensitivity.

Photo of testing equipment setup Block digram of testing equipment setup

Measurement Method:
Vectron carefully monitors the products of Quartz blanks for low g–sensitivity performance with the use of custom metrology equipment. For instance, the convex contour of our blanks is analyzed by the laser profilometry.

Photo of Laser Prolometry Equipment Plot Blank Profile

We have put extensive efforts into identifying the root drivers of g–sensitivity in our crystals

Photo of displacement imagery Plot of Total Gamma vs Contour Offset

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