Patent ID: 6731681
Filing Date: 2004-05-04
Classification: G01R

Abstract:
A method for determining frequency instability noise &Dgr;TRMS of a source, comprising the steps of:determining a signal to noise ratio SNR1 at an output of an analog/digital converter having an input for receiving a frequency input signal ft, an output for supplying an output signal, and a sequencing input for receiving a clock signal, the clock signal being a reference signal having a frequency instability noise level which is lower than a level of frequency instability noise from the source; determining a signal to noise ratio SNR2 at the output from an analog/digital converter, the clock signal being a signal from the source; and calculating the frequency instability noise &Dgr;TRMS from SNR1, SNR2 and ft so that: Î”&it;â€ƒ&it;TRMS=(10-SNR210-10-SNR110)122&it;Î &it;â€ƒ&it;ft.