Network Analyzer, Signal generator-Spectrum Analyser

hi,

we have 3 IF outputs in a Receiver.

The Network Analyser is showing -50dB for the isolaiton betweeen IF1 - IF2 (frequency range was 10MHz- 4500MHz).



the same thing when measured in signal generator and spectrum analyser it is showing -70dB @ spot frequency of 100MHz.


which one is correct? which one is valid test setup?

regards
Chandre

I think the 2 method make no difference in theory. But Signal generator & spectrum analyzer result should be more reliable. The accuracy depends on:
1. the RBW and noise level of the equips.
2. the DUT is not satuated.
3. the signal has low harmonics and the receiver has good selectivity.
I think the VNA can get the same result by set RBW to 100Hz or less and power to -30dBm or higher.