[time-nuts] Phase noise and jitter

Javier Serrano javier.serrano.pareja at gmail.com
Mon Oct 13 21:04:49 UTC 2008

Said, what is the operating principle of the Wavecrest Jitter Analyzer?
Is it a sampling scope like the ones Agilent and Tektronix offer? How
does it compare to them? I've googled it but I only found a Chinese site
with little information in English. Another advantage I see for
time-based measurements is that you can go arbitrarily low in offset
from the carrier. In the 5052B you have a PLL with non-zero bandwidth,
so below some offset you probably get an optimistic estimate because the
PLL is actually following the noise. Another item to bear in mind, if my
understanding is right, is that integrating the phase noise plot gives
you the rms jitter between your noisy waveform and the perfect sinewave,
or rather an approximation of it, which is what comes out of the PLL in
say the 5052B. A sampling scope typically measures the time jitter
between two (noisy) rising edges of a clock waveform. In the simplistic
case of white phase noise this should give you a factor sqrt(2) more
jitter than the loose PLL measurement, right? 
Thanks again,

More information about the time-nuts mailing list