biasing for power amplifier and checking s-parameter at o/p port

[vkschaudhary2010]

Hi
I am working on class-E power amplifier by using transistor as ATF52189 and i want to know how to get same s-parameter at o/p port mainly(S21) value.
and how to check voltages and current at different nodes at point 'A' in image, if we apply voltage source at drain and gate? figure is attached please refer?
Hope for a reply.

 

[hari_preetha]

You didn't mention, which software you are using. You go to help in which software you are using. You search whatever you want.

 

[BigBoss]

You cannot obtain AC voltages and current in s-parameters simulations.You may just see small signal input/output relations between the ports.
You have to do either HB simulation or Transient Simulation with a proper nonlinear model.If you use ADS, there is a Design Guide for Large Signal Test Benches for E-Class Power Amplifiers, they are practical for you.

 

[vkschaudhary2010]

Class-E power amplifier stability

thank you for replying. I am working with ADS 2011 software and getting problerm in getting a same s-parameter at o/p port for making the transistor stable.
Can u please tell me how to do so?

 

[mtwieg]

Class E amplifiers can't be characterized with S parameters to predict or control stability, as they are nonlinear. I'm not sure if there is a standard stability test for class E amps, but ADS does have example designs for large signal characterization of class E amps.

 

[BigBoss]

Re: Class-E power amplifier stability

thank you for replying. I am working with ADS 2011 software and getting problerm in getting a same s-parameter at o/p port for making the transistor stable.
Can u please tell me how to do so?

Stability can be observed the s-parameters under small signal conditions.Since the voltages and currents are large, it should be noted that the OP of the active device is not valid anymore so s-parameters are not valid anymore and they are time changing.

Large Signal s-parameters ( and their simulation ) can be considered for mild/weakly nonlinear circuits to predict stability and other stuffs but your case is pretty different.
A Class-E amplifier is strongly nonlinear and Large Signal s-parameters may not give you an insight about the stability ( they may give too ). If I were you, I do large signal s-parameters simulation in different loading conditions ( extreme cases )