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Post subject: Out-of-Band and in-band noise measurement
Posted: Sat Jun 16, 2007 3:23 am
Joined: Sat Jun 16, 2007 3:02 am
I have question relative to OOB and IB noise measurement. We have a requirement to meet with spec for OOB is -140dBm/Hz at 1.5G and 1.89G with operating frequency at 2.5G and Pout=25dBm. I have some idea, but not sure if it is correct. DUT is WIMAX PA. This is what I would do:
1. Provide WIMAX signal to input of the DUT.
2. Measure at output for 25dBm.
3. Connect a low pass filter with 20dB or better rejectionat the output. This is prevent the operating frequency from over drive the Spectrum Analyzer while not attenuating the OOB noise at 1.5G and 1.89G.
4. Use Marker Function on SA to measure noise power level at 1.5G &1.89G.
Does this sound OK and is it the way to do OOB noise measurement (I could not find specific apps note for this OOB noise measurementanywhere).
Regarding to In-band noise measurement: I would apply no RF& no DC to DUT, measure noise with Marker function to find system noise floor.Then apply DC (no RF), and make measurement with Marker function.
Please advise and comment.
Posted: Tue Jul 03, 2007 4:03 am
Joined: Mon Jun 27, 2005 2:02 pm
Sounds perfectly good! I would do exactly the same.