Hello all. I have an E4440A with the Phase Noise personality, Option 226. I have tried to measure the phase noise on several generators with known phase noise below -126dBc/Hz but the best I can obtain on the E4440A is -119dBc/Hz. I performed the DANL performance test and it passes with flying colors. Could there be a problem with the E4440A's LO? If so, how could I verify it? Is there anything else I should be looking at?
The PSA series specifications guide can be found at:
http://literature.cdn.keysight.com/litweb/pdf/E4440-90647.pdf
Specifications for Noise Sidebands start on page 35. Also, chapter 2 is specifically for the Phase Noise Measurement personality.
Regards,
Mike