I am trying to do a PSRR analysis of an LC_VCO using PXF analysis. I am following the procedures given in cadence app note 'Power Supply Rejection Ratio Characterization Using SpectreRF Autonomous Circuits'.

When I plot the transfer from 'SSB' of input to 'PM' of output I get a graph with units in dB20(V/V). Is this a graph of 20 log * (Output Phase Change in Radians / Voltage Peak at Input). ie. Is the unit dB (radians/V)? or is it dB (degrees/Volt)?

Because I dont understand how it can be V/V for a Phase modulated output vs a single side band input.
Thanks.

p.s. BTW, the final few pages of the app note specify the unit of phase to be in degrees. But I am just confused that the graph displays it as dB20(V/V)