Driver design of the power amplifier

OZZAA said:

I want to design a PA with 2 stages (Driver (Cascode topology) and the main PA (Common source)) to give for example maximum power equals 30 dBm (@10 GHz) with overall gain 15 dB.
I calculated the aspect ratio of the transistors of the main PA to be in class AB.
its S21 is about 6 dB.
How I can choose the aspect ratio of the driver stages to feed the main PA properly.

I know I have to make the gain of the driver stage (s21) equals 9 to give the overall gain equals 15 dB.
and what is next?
you can assume any output and input resistances and any other wanted data, I just want the concept.

Thanks in advance

Click to expand...

you need to design driver with the output power that is needed at the input of your second stage --> Pout 1dB (driver) = Pin (PA)

Click to expand...