Why does the input of the amplifier have the stub feeding into the bias resistor network, I thought its suppose to go to ground? My guess would be that its convenient, since it would take up less space and will obey the superposition principle?
Why couldn't have they used DC blocking capacitors before the transmission lines instead of after, couldn't that have kept them from having to use a bypass capacitor at the stub of the output?
I think this schematic is theoretical and designed only for educational purpose.
Printed stub tuners are used for high frequencies, greater than about 800MHz.
The entire schematic use for DC blocking and for decoupling only 0.1uF capacitors, which are totally useless at high frequencies.