Dual stage power amplifier

Hi,

I posted in another thread the following design of a PA:
View attachment 68001

IREF, VB (3.5V) and VDD (3.5V) Ports are DC signals.
IN Port is the input power (up to 0dBm).

What is the first stage role?
Is it correct to say that the power is being amplified only at the second stage?

Thank you very much.

After a quick look, it appears that both T1 and T2 should be providing some power gain. They are both common emitter amplifier stages, with seemingly appropriate base bias, appropriate DC decoupling on the collectors and an impedance matching network to the next stage. However, C9 doesn't make any sense. I suspect the value is incorrect. It is way too large a value at the moment to be a useful impedance matching element. If it is an ideal capacitor, it is shorting the signal to ground. If it is a real capacitor, it is being used well above its series resonance, perhaps with unpredictable results, but in any case it is probably too low an impedance.

Yes, both stages are amplifiers - gain of high frequency transistors is extremely low so it's normal to need multiple stages.

A 2m amplifier I built years ago used a single transistor, it took 10W input and outputted only 40W, so a gain of only four times (and that was only at 145MHz).

Thank you very much Ron and Nigel!

Hi again,

Could you please help me understand the operation of the following DC to DC voltage converter?
View attachment 68033

The CMP signal is a sawtooth wave.
Is it correct to say that large Duty Cycle of the CMP signal produces high voltage at the output? (Load port)