Post subject: NF and Gain Measurement using SA & Noise
Unread postPosted: Sun Jul 11, 2004 5:38 pm
help me to Measure LNA NF & Gain using Spectrum Analyzer &
Unread postPosted: Tue Jul 13, 2004 12:51 pm
Joined: Sun Aug 03, 2003 2:02 pm
Location: Erie, PA
has an application note for that here:
Measurements and Noise
Application Note 1303
- Kirt Blattenberger :smt024
Post subject: Using Noise
generator for NF measurement
Unread postPosted: Tue Dec 14, 2004
Sorry the Agilent app note referenced in the other
reply will not help you .
see instead /5952-3706E.pdf.
You need to set your spec. an. to work as a RF power meter.
1. Set IF bandwidth high as you dare.
2. Set Video filter
as low as you have time to wait for trace.
3. Set to 1 dB/ div
or if youre lucky use a maker at the centre of your noise.
You will need a low noise preamp if the gain of your device or system
(DUT) is gain is less than about 20dB.
5. Check for this - the
noise level should drop by at least 10dB when you disconnect or
power down your DUT.
6. If not use minicircuits or other gain
block amplifier to get result 5.
super low noise not required
about 4dB is OK.
7. Connect noise generator to DUT. switch on,
your spec an noise should jump at least 3dB.
8. Apply Y factor
formula to calculate result from generator ENR, ambient temp (ussually
assumed), and change in spec. an. dB reading noise generator off
to on. Y is this dB reading converted to a straight power ratio
9. Y factor method formulas are on the net see /5952-3706E.pdf