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Measurements >> Phase Noise and Jitter Measurements >> Spectrum analyzer spurs measurement
https://designers-guide.org/forum/YaBB.pl?num=1519804579

Message started by iVenky on Feb 27^th, 2018, 11:56pm

Title: Spectrum analyzer spurs measurement
Post by iVenky on Feb 27^th, 2018, 11:56pm

Hi,

I have a question regarding spectrum analyzer spur measurement. If I want to know the spurs with respect to carrier power level, should I use the phase noise feature of the spectrum analyzer or find the dBc value directly on the spectrum (which may include AM noise also). I see different results using both ways. Which is correct? I am more interested in Period Jitter due to spurs.

Title: Re: Spectrum analyzer spurs measurement
Post by deba on Feb 28^th, 2018, 8:44pm

Phase noise analyzer is equivalent to limiting the input with a limiter and then seeing the voltage spectrum. If one use a voltage limiter(which will limit the AM noise), spectrum analyzer output and phase noise analyzer will be identical.

As you have mentioned, with spectrum analyzer there will be AM noise but with a voltage limiter the AM noise will be suppressed.

Thanks