Forums › SA Series Discussions › Discontiunity in noise measurement
- This topic has 3 replies, 3 voices, and was last updated 7 years, 2 months ago by Justin Crooks.
elieserParticipantelieser January 20, 2016 at 8:27 am
I’m looking at the noise from my amplifier circuit with the SA44B, but I’m getting a strange discontinuity around 16MHz. I run the same test with a different spectrum analyzer and there is no dicontinuity. Overall they look similar, but why is there a 3dBm drop at 16MHz? See attached data sets.
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AndrewModeratorAndrew January 20, 2016 at 11:57 am
At 16 MHz the SA44B switches over to a more sensitive IF which is why you see the step in the amplitude.
elieserParticipantelieser January 20, 2016 at 1:34 pm
Can that be calibrated out? My plots look horrible with a sharp 3dBm drop right in the middle . .
Justin CrooksModeratorJustin Crooks January 20, 2016 at 2:25 pm
You can turn image/spur rejection off. This will force it to stay in the higher noise state, but also lets spurious signals through. Note that with the SA44B there is a 3 dB correction for broadband noise, as the software image rejection cannot filter out noise at the image frequency.
The BB60C can perform this measurement without the correction.
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