Input Output Admittance/Frequency for BJTs

How can I calculate-simulate the input output admittance of a BJT transistor in various frequencies? The Datasheet doesn't include the information I need.

Hi,

To convert S to Y use

Y11 = 1/Zo((1-S11)(1+S22) + S12S21/((1-S11)(1+S22) - S12S21))

Y12 = 1/Zo(-2S12/((1-S11)(1+S22) - S12S21))

Y21 = 1/Zo(-2S21/((1-S11)(1+S22) - S12S21))

Y22 = 1/Zo((1+S11)(1-S22) + S12S21/((1-S11)(1+S22) - S12S21))

You can also simulate that with ADS using function ref y=stoy(S,zRef)
or use BJT model and plot the impedance/admittance in various freq using ZY chart



Goodluck...

Thank you for your pdf docment

I am afraid the only software I have available to use is microwave office. Does it have this option as well?

Can someone who has ADS help me and post the admittance here?

The spice model for An2221 is :

Q2N2221A NPN ( IS = 426.3f XTI = 3.0 EG = 1.11 VAF =250.3 BF = 72.14 ISE = 48.14p
+ NE = 2.935 IKF = 2.935 NK = 1.401 XTB = 1.5 BR = 11.49 ISC = 19.9f
+ NC = 1.88 IKR = 10.75 RC = 0.3567 CJC = 11.02p VJC = 0.3869 MJC = 0.3292
+ FC = 0.5 CJE = 29.31p VJE = 0.9036 MJE = 0.4101 TR = 16.89n TF = 537.5p
+ ITF = 0.1383 XTF = 84.83m VTF=10 )
*

I need the input and output admittance for the frequencies: 100Mhz and 10.7Mhz

I'd be gratefull for some assistance!