Andrew Beckett wrote on Jul 31st, 2006, 9:25pm:It calculates the small-signal gain over the same frequency range that you did the noise sweep. So the gain is frequency dependent, as you say. Noise analyis computes the magnitude of each noise source, and then multiplies that by the transfer function from that noise source to the output, The same method of calculating transfer function is used for the signal input.
So you end up with a sum of all the noise powers at the output (over frequency). You can then divide this sum by the signal gain (again over frequency) to get the input referred noise (over frequency). Often the output-referred and input-referred noise are then integrated over a particular bandwidth to give you the total noise power in the bandwidth of interest.
Regards,
Andrew.
Hi Andrew,
Thanks for the helpful explaination.
But some papers said the input reffered noise is the total output reffered noise divided the gain(mid-band gain). According it, the gain should not be frequency dependent, i.e., the input reffered noise is not divided by the transfer function from input to output(it is freq dependent), but divided buy a single gain.
Would you pls. help to clarify it?
Thanks