How Calcute Impedance

Helo evey one,
I am working In PA Matching I used ADS as simulator tools,,,
now I wont to determine the input and the output Impedance of the Transistor with ADS,,
Any method to this.

Thank you

insert the S-parameter block and simulate with you desired frequency range.... plot S11 for input impedance over your range and S22 for output impedance over your frequency range.
these plots shows impedance of transistor at input and output at different frequencies

Do the following:
1. plot your forward reflection (S11) and reverse reflection (S22) on a smith chart on ADS
2. set a marker on your deseired frequencies
3. read out the impedance values