# If i measure a rf source as 20 dBm in spectrum analyser inline with 20db attenuator, what is the actual power generated by rf sorce

Measurement 20dbm + 20 db attenuator, what is the actual power of rf source

• If the source is much narrower than the RBW then it's simply 40 dBm. But if the spectrum analyser was set narrower than the source, you have to do some integration over frequency. Oct 6 '15 at 4:06