Hello everyone,
I have tried to simulate the phase noise(PN) in SpectreRF because of the PSS & Pnoise analysis. However, the PSS analysis can not be convergence well. So I wonder if Hspice can do the same function as PSS & Pnoise in SpectreRF.
Firstly, I think the PLL circuit can obtain the steady state after a long time by tran analysis. And then I can save many operating points in a period wave. Just like the PSS analysis in SpectreRF.
Secondly, I can use these OP values to do noise analysis. But at this time, a problem occurs: How to consider this?
"Active elements with a time-varying bias point can convert noise from one frequency to another, a process known as noise folding, regardless of the origin of the noise."
Reference in the manual "Periodic S-parameter and noise analysis using SpectreRF PSP/PNOISE analyses"
Who know how to consider the noise folding effect in Hspice?
Thanks & Best Regards
Vincent Lee

Also, as you say you are trying to simulate a PLL, you should
read Ken's paper:

http://www.designers-guide.com/Analysis/PLLnoise+jitter.pdf

which goes into this in some detail. I suspect that you may
be trying to simulate the whole PLL in one go, which is often tricky... (see the paper for more info).

Regards,

Andrew.