Latvian Patent No. 14455 “The method of evaluation of precision generators period jitter”. Inventors: V.Bespaļko, J.Buls. Owner: Institute of Electronics and Computer Science. Published: 20.03.2012.
An invention is related to the measurement technique, particularly the technique of the period jitter (short instability) measurements for precision generators. As to the offered method the measurements of defined number of n sequential periods Ti of the researched generator are being made, and each i-th period is measured by two measurement channels A and B. The evaluation of the period jitter of the researched generator is defined from the covariance evaluation for accumulated arrays and of measurement results. The correct evaluation is possible if the condition of independence of both channels measurement inaccuracies ai and bi is fulfilled ().
In the offered method the bigger or smaller period measurement inaccuracy leads just to bigger or smaller dispersion of the attainable jitter estimates, but repeating measurement cycles N times increases the precision of evaluation times. It is possible to obtain in similar way the evaluations of the jitter of time intervals, which are being generated by the precision generators. Experiments showed that using of the offered method allows obtaining evaluations of subpicosecond jitter of both the period and time intervals that are being generated by the precision generators.
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