The Designer's Guide Community Forum

The Designer's Guide Community Forum
https://designers-guide.org/forum/YaBB.pl
Simulators >> RF Simulators >> pnoise analysis
https://designers-guide.org/forum/YaBB.pl?num=1134263409

Message started by Paul Geraedts on Dec 10^th, 2005, 5:10pm

Title: pnoise analysis
Post by Paul Geraedts on Dec 10^th, 2005, 5:10pm

Hi!

During recent pnoise simulations two questions came up.

First, why does the list as produced by the 'noise summary' option (of the 'analog design environment') add up to more than 100%? Doesn't it take the correlation between noise sources into account or so?

Second, due to inclusion of a semi-digital datapath to an existing oscillator the beat frequency has halved; the state of the resulting circuit is now periodic with twice the clock period. During the calculation of the phase noise of the oscillator I started doubting about the sidebands to include in the pnoise analysis to account for noise folding. Am I right to include all sidebands up to the preferred maximum sideband? Or should I only include the even sidebands (so exlude the odd sidebands)?

Thanks a lot in advance!

Paul

Title: Re: pnoise analysis
Post by Paul Geraedts on Dec 13^th, 2005, 2:49pm

It turns out that the 'noise summary' option of pnoise also contains negative contributions! Can this be anything else then a bug?

Title: Re: pnoise analysis
Post by Andrew Beckett on Dec 13^th, 2005, 3:12pm

If the output format has been selected as V^2/Hz, it definitely sounds suspicious. I think you should report it to customer support - you'll almost certainly need to provide a testcase - so that it can be investigated further.

Regards,

Andrew.