simulate Z0 from s2p file

[myem]

When I am simulating s2p file.
How can I know the Z0 from this s2p file ??

My simulation tool is Agilent ADS.

 

[VSWR]

Here is an example of an S2P file for the Siemens BFP193 transistor. Locate the line

'# GHz S MA R 50'

The '50' means measurement have been carried out in a 50 ohm system. Which is the most common impedance used in S2P files.

! SIEMENS Small Signal Semiconductors
! BFP193
! Si NPN RF Bipolar Junction Transistor in SOT143
! VCE = 5 V IC = 12 mA
! Common Emitter S-Parameters: May 1996
# GHz S MA R 50
! f S11 S21 S12 S22
! GHz MAG ANG MAG ANG MAG ANG MAG ANG
0.010 0.6969 -7.8 30.560 176.0 0.0030 86.8 0.9714 -3.9
0.020 0.6973 -15.2 29.671 170.5 0.0064 82.7 0.9621 -7.5
0.050 0.6825 -36.7 28.155 158.5 0.0156 73.5 0.9154 -18.1
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