PA input impedance matching with on-chip components

[Alex_IC]

I am designing silicon PA for 3GHz. I have to put 100 transistors in parallel to get transistor which is capable to deliver enough current into the load. And the input impedance of the transistor at 3GHz is 0.3-1*j. Is it possible to match the input with on-chip components?

 

[BigBoss]

pa input impedance

Why don't you use a pre-driver amplifier to increase input impedance and isolation??
As you see, input impedance approx. purely capacitive, so matching will be consisted of inductances that are lossy components..
If you compensate the loss of interstage mismatches by an additional amplifier, you won't need to match exactly this very strange input impedance to 50 Ohm..

 

[Alex_IC]

input impadanz pa

I am trying to devide the two stage PA into two one-stage PAs. I do that in order to measure what is the input impedance of output PA stage in reality. Because the BJT model I have is standart Gummel-Punn and I have heard that this model is not accurate enough for PA simulation. So I wanna match input of the output stage to 50 Ohm for measurement purpose and de-embed the input matching transformer after to get the input impedance.

 

[kspalla]

PA input impedance

It is always good practice to match the input of final amplifier impedance with the driver output impedance.
You will avoid reaching the 50 ohm in smith chart. this leads reduced art size.

You can do the driver output impedance to 50 ohm and then to input impedance of final amplifier if their impedance are near / almost complex or so.