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Simulators >> RF Simulators >> Pnoise simulation for LC Oscillator
https://designers-guide.org/forum/YaBB.pl?num=1090231519

Message started by froggy on Jul 19^th, 2004, 3:05am

Title: Pnoise simulation for LC Oscillator
Post by froggy on Jul 19^th, 2004, 3:05am

I am doing a LC Oscillator design at the present moment and I would like to run a phase noise simulation. Under what condition, should I set "Input Source" in the Pnoise analysis form? ???

Title: Re: Pnoise simulation for LC Oscillator
Post by Eugene on Jul 19^th, 2004, 8:22am

I believe I can answer this one if I understood your question correctly. I believe you want to perform an autonomous PSS analysis followed by a pnoise analysis. There should be no independent periodic sources in your schematic. However, you may have non-zero DC and perhaps AC sources. I believe the "input source" entry in the pnoise form defines your input point for noise figure analysis. Since you are interested in phase noise, not noise figure, you are free to chose any independent dc or ac source you like. (By ac I mean small signal frequency domain source, one that does nothing in a tranisent simulation.) The source you chose makes no difference in your phase noise analysis.

Title: Re: Pnoise simulation for LC Oscillator
Post by Andrew Beckett on Jul 21^st, 2004, 12:48am

In fact you probably want to set the input source to "None" (you
have a choice of voltage source, port, current source, or None),
since the input source is usually irrelevant for an oscillator
unless there is some source you want to input refer the noise to
(unusual though).

Andrew.