aaron_do
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Hi all,
I want to do an input referred noise (IRN) measurement for a 2 MHz low pass filter. I have a spectrum analyzer and a noise source (minimum noise level output is -30 dBm). for now i just want a rough measurement, and i'll get better equipment later. How would I measure the IRN?
The noise source outputs -30 dBm, so I assume that is the total integrated power. At the spectrum analyzer, I read about -60 dBm at the passband frequency with a resolution bandwidth of 100Hz. So my thinking is that i have to integrate the noise over the entire bandwidth. So i was thinking as an approximation i could use the -3 dB bandwidth divided by the resolution bandwidth (of the spectrum analyzer) and multiply that by -60 dBm. Next divide by the gain of the filter, and subtract the source noise (-30 dBm). So that would be the answer.
Is that correct? Also what is a good way to integrate the noise over the desired bandwidth?
thanks, Aaron
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