Vector Analyzer: what is IF bandwidth?
SNR is a power ratio of Ps/Pn, but as the voltage ratio it would be Vs²/Vn².

If we look a carrier sweeping thru a BPF, we take one half of -3dB BW to get the single sided Low Pass equivalent time response.


This may be simplified and another way of looking at it is;

The Spectrum Analyzer Local Osc, LO Sweep rate = span/sweep time= RBW²/k    

The IF is the final mixer Intermediate freq. selected.
RBW = Resolution BW
k = constant that affects accuracy.

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