[SOLVED] ATF-34143 ADS model to S2P file S parameter comparison in ADS

[Reschak]

Hi

What I'm trying to do is create a bias network for avago ATF-34143 transistor model in ADS which matches the plotted S parameters of an S2P file to that of an ADS model of the transistor with a bias circuit. Bias at VDS=3 V, IDS=40 mA.

Both the model and the S2P file of the transistor are obtained from avago's website here:


The S2P file I'm using is the f341433b.s2p - ATF-34143 s and noise parameters at 3 V, 40 mA (1 KB,S2P).

After doing this, the plots for the two simulations do not match. I have don't know why but it's probably the bias circuit I'm thinking.

I've attached some screenshots which should make things clearer.

All suggestions welcome, I am well and truely stuck. Thanks!

 

[BigBoss]

The conditions are not same ...​

1-s-parameters are measured "Emitter/Source Grounded and Input and Output is terminated by 50 Ohm Characteristic Impedance"
**You used a series emitter resistance and it changes too much s-parameters.
**You have to use ideal RFC instead of Drain/Collector resistance.This R will truly change the s-parameters because it's shunted to termination impedance.
**And Gate/Base bias circuit is also not correct.You have to drive the transistor either a ideal current source for BJT or a ideal Voltage source with a RFC for FET.

 

[Reschak]

Makes much more sense now. Thanks so much!