I'm using the A model of the PNA-X with the embedded LO option, as well as option 90 spectrum analyzer function. I'm trying to test a upconverter DUT with a -70dBm input power requirement. The gain should be about 65. However, when I tried it with the embedded LO function on an SMC channel, it should shows a gain of about 7. When I perform a option 90 spectrum analyzer sweep though, I able to get the output tone of around -5dBm. So I'm wondering what should I do to get the embedded LO SMC SC21 gain measurement to match the expected value shown from the spectrum analyzer trace. Or is there a limitation in the embedded LO capability?
Here are my settings:
Broad & precise
Tuning IF BW=1kHz
Tune Every 1 sweep
and the 'LO Freq Delta' is 26.68kHz.