jitter and noise convert ?

Dear all:
I design Differential Ring OSC, using spectreRF sim phase noise
170Mhz@50khz is -80dbc/Hz , I want to know :
1. how to convert to cycle to cycle jitter ?
2. phase noise can be better ?
3. how to measure VCO phase noise in testing ?
now I use D2S circuit for test VCO is ok ?

Thanks .

hello,
"2. phase noise can be better ?"
Is depinding of oscillator type for an LC tank jiter can be
-130dBc/Hz

To convert jitter-phase noise see: Clock (CLK) Jitter and Phase Noise Conversion - Maxim
to measure VCO phase noise, you can use a spectrum analizer, if you don't have a dedicated instrument. This will limit the lower offset you can measure, to few kHz (due to freq instability).
Another (cheap) way to measure phase noise of VCO from few Hz offset, is to lock it in a PLL with a very low bandwidth. To do so, you need to have available the control voltage pin and the output of your VCO.

I hope it can help.

Mazz