Re: pll design
U can analyze the jitter by the phase noise. The ADS and SpectrRF can hlpe you fininshing these things. It can provide you the lower bound of the jitter of ur circuit, because it olny calculate the device noise not including other noise which from power, reference and substrate noise.
As the result, u should be careful about these items by yourself.
If you would like to reduce your jitter more, raise the order of the loop-filter is another solution.
FYI.