reference impedance in smith chart from cadense

Hello all,

I have a single ended 2 GHz amplifier , i am using Spectre simulations to make S parameter simulations, and using simultanuous input output matching technique mentioned in Gonzalez book, my problem now is that the sourse impedance is 150 ohm and load impedance is 25 ohm, so what is the reference impedance of the resulting S-parameters inorder to get correct calculated matching impedances? when i asked cadence support they said that s parameters are normalized to input impedance, but this give me very strange "large" Zin and Zout.

I appreciate any help,