GDF said:By the way, may I use this spectrum analyzer to measure noise floor of a system
such as active filter?
sergio mariotti said:Generally SA are not low noise instruments. Most of them, syntetised or not, very expensive or expensive, have an equivalent input noise figure of 30...40 dB when input attenuator is set to 0 dB.
Take in mind that noise figure constant even if you ghange resolution bandwidth.
I don't think SA may be used to measure noise floor withoud a preamplifier
In the front panel of SA you should read the frequency range, usually the lower freq. is 9 KHzI insert an unity gain buffer based on OPamp between my DUT and spectrum
analyzer. My interesting frequency is from 200Hz to 100KHz, and the Spectrum
Analyzer is hp 8601E. My question is can I trust the measurement result?
Because this is an RF spectrum analyzer, but my interesting frequency is
below hundred kilo hertz.
The input stages are composed by an attenuator followed by an expensive mixer. The mixer is DC coupled. a DC voltage ≠ 0 will destroy the mixer.By the way, I heard we can't feed DC to our spectrum analyzer before, but I dont' know the reason until now. Can someone tell me why?