Spectrum analyzer measurement
Spectrum analyzer measurement
(OP)
Hi,
well, I´m going to ask a basic question but I´m finding some difficulties when measuring power levels with the spectrum analyzer (SA).
I will reduce my problem to a basic question:
If I connect a signal generator to my SA with a 200MHz sine tone what should be the SA settings to get the most accurate measurement? specially, RB, VW. I have seen big differencies depending on the settings.
What I have tried is to do a 0 span measurement and use a marker. That gives me just the cable losses, around 0.2dB.
well, I´m going to ask a basic question but I´m finding some difficulties when measuring power levels with the spectrum analyzer (SA).
I will reduce my problem to a basic question:
If I connect a signal generator to my SA with a 200MHz sine tone what should be the SA settings to get the most accurate measurement? specially, RB, VW. I have seen big differencies depending on the settings.
What I have tried is to do a 0 span measurement and use a marker. That gives me just the cable losses, around 0.2dB.





RE: Spectrum analyzer measurement
In zero span you are creating a downcoverter and a scope so you are looking at teh time domain.
RE: Spectrum analyzer measurement
Well, I wanted to know how to set the RBW and VBW properly. I am aware that the power measured depends on RBW a per 10logBW2/BW1.
Well, I´ll check it again!
Thanks.
RE: Spectrum analyzer measurement
In any case you should be able to read off the screen. The top of the screen is the "reference level". If you are on 10dB per div, the reference level is 0dBm and your signal is one box down from the top, the level is -10dBm.
Set the centre frequency to 200MHz and the frequency span to 10MHz to get a sensible picture.
RE: Spectrum analyzer measurement
In general, if you make the RBW (maybe 3 MHz)as wide as possible, you will get an accurate measurement. But, obviously, if the signal is jumping around +/- 5 MHz, then a 3 MHz RBW is not wide enough!