The Modeling And Compensating Of Crystals Aging Drift

In addition to temperature drift,the aging drift of crystal oscillator is an important factor of which affect the frequency stability and accuracy of crystal oscillator. This paper studies the crystal oscillator aging drift, firstly, it introduces the crystal oscillator, and analyzes the mechanism of aging.Then,this paper analyzes many groups of OCOX aging drift data,Combined with mathematic modeling method,use MATLAB to establish mathematical the model of crystals aging drift,and verified and improvement.In the course of modeling, first,Use Savitzky-Golay algorithm filtering processing the data in the early period of the aging drift of OCOX,then use the smoothed data by the nonlinear least squares to the model for parameter estimation,the next, using the specific model from above to simulate and predict the aging drift of Crystal.By comparing the prediction and the actual test data,judge the model of the pros and cons,if the effect of the model to simulate and predict is not beautiful,improve the model.In addition,This paper use two groups of OCOX data measured in the laboratory to Validate the established mathematical model of The crystals,the verification results show that the proposed model predicted the crystals aging drift has good effect.Finally, this paper puts forward a scheme for the crystals of aging drift compensation which combined with the suggested mathematical model of the crystals and the DDS technology,and describe the hardware and software of scheme.