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Simulators >> RF Simulators >> incorrect noise summary report for modulated pnoise analysis
https://designers-guide.org/forum/YaBB.pl?num=1465985302

Message started by Ruiyan on Jun 15^th, 2016, 3:08am

Title: incorrect noise summary report for modulated pnoise analysis
Post by Ruiyan on Jun 15^th, 2016, 3:08am

Hi fellow spectreRF users,

When printing noise summary report for a pnoise analysis, I noticed the contribution from a particular noise source doesn't correspond to the real impact it has on phase noise. I'm using modulated pnoise to the phase noise but the report does state at the bottom that this report is for unmodulated pnoise analaysis.

What I noticed is if I remove a noise source without changing the operation of the circuit at all, the reduction in phase noise doesn't correspond to the removal of the contribution. In theory it should.

For example, if a supply noise has 50% contribution, removing it doesn't reduce the phase noise by 3dB - when it should be exactly that.

Does anybody have the same problem or know how to correct this to make the noise summary report contribution agree with their effect in real phase noise?

I guess I'm only seeing this problem because I use modulated pnoise to get true phase noise (not the pnoise from the direct plot form).

My Cadence version is IC6.1.6. Guessing it might be fixed in newer versions?
Many thanks guys.

Ruiyan