Today, I tried to measure the NF of RF power
amplifer with Aglient Spectrum analyzer and
Signal generator. I know there is three ways to
1. use NF analyzer (I don't have
2. Q-factor (I don't have two noise
3. Gain method. NF =
The problem as
1. The Pn(tot)@output is
~-70dbm[pwr in 0dBm, Gain(RFPout-RFPin):32dB, PA
is working(Vcc(3.5v), Vpc(2.2v, 25%DC)), center
frequency 1710MHz]. So base on the result, the
NF of PA should be ~68dB:-(. it is impossible.
My question are
1. Did I do something
wrong during test NF?
2. Did the formula
right for cal NF by Gain method?
3. Do I need
to set the fixed RBW for Spectrum Analyzer? Is
there any relationship between NF and RBW
setting for SpecAnalyzer?
4. Could anyone
provide me some other ways to test it with my
available equipment? as well as any helpful