AnsweredAssumed Answered

Phase noise measurement error

Question asked by Evgy on Dec 22, 2008
Latest reply on Apr 10, 2009 by jborges3
I am measuring phase noise for a phase modulated signal.
I am using MXA N9020A, PN mode, log scale measurement, minimal span and sweeping through few modulation freq
(also I have used the averaging function and received the same results)

I receive a jump of about 15 dB !!! at around 1MHz PM, as can be seen at the following pics:

What can be the reason for that, and what can I do to fix it ?

for 0.8 MHz modulation freq
Image

for 0.9 MHz modulation freq
Image

for 1.0 MHz modulation freq
Image

for 1.2 MHz modulation freq
Image

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