AnsweredAssumed Answered

Frequency Translation -- Residual Noise

Question asked by ecrean on Jul 11, 2006
Latest reply on Jul 12, 2006 by ecrean
To Joel??

We are building a dual conversion up-converter.  To measure the phase response, we use an external mixer to downconvert back to the RF input frequency (140 MHZ).  When we try to measure phase, we have +/- 0.25 degrees of random phase data displayed on the PNA.  The amplitude is rock solid and virtually noise free.

What would cause this random phase noise? All the sources are locked, and probing through the circuit we know it is not generated by the up-converter module.

Our PNA is a standard model.  We do not have the mixer measurement options.


Ed Crean
Sr. RF Engineer

Symtx Inc <custom test solutions>
telephone: 512.328.7799 x293
fax: 512.328.7778