Re: Noise figure measurement
Generally, when somebody ask what is the right instrument, they hyde a more deep question: what are the uncertainty i can reach? And how?.
This is more true on noise measurement.
Agilent spectrum analyzers options are not very accurate, or said better, the added uncertainty is not negligible.
Anritsu Skorpion is the only instrument that play a vector error correction for Noise generator reflection coefficent, but basically U(ENR) still remain =0.1dB or more. Anritsu Skorpion is better than Agilent 8970.
Agilent NFA is sold with an innovative Noise Generator that U(ENR) =0.05dB. No other instrument around the world is more accurate.
On the other hand, the user is called to accurately characterize the adduction lines.
This is a very difficult job. To do a good job, the Gav (available gain) of the adduction lines should be known with U(s21) <0.05 dB and Γon ≈ Γoff (both < 25 dB).
The user should choose the best matched probe to feed the LNA input.
The physical temperature should be nearest possible to 290K (17°C).
The ENR setting on the NFA should be corrected (with an appropriate method) for the Gav of the adduction line and it's temperature.
Etc. Etc.