2.4G .13u Non-saturated ring oscillator's peak-peak jitter

Hi, Folks:

What's the reasonable phase noise @ 100K offset frequency by ring VCO on 130nm process?

The ring oscillator is of type much like Razavi's text book, non-saturated type.
I am optimizing the phase noise. It is nice to know its limitaiton, so that what's the best I can have.

thanks,
Han