Why carrier amplifier has 100 Ohm impedance at low power in Doherty amplifier? Shouldn't it be 50 Ohm impedance, because the carrier amplifier is always on? What is happening to frequency response as amplifier is matched to 50 Ohm faces 100 Ohm Doherty combiner?
Thank you for your time!
Hello Audrius Merfeldas
May be the following article will help:
Article The Basics of the Doherty Amplifier
In the figure you are showing one of the transmission lines has a different impedance than the load ((1/sqrt(2))*Z0). Thus part of the energy is reflected back increasing the voltage at the carrier amplifier while the peak amplifier is in high impedance state.
Audrius Merfeldas
The simple reason is that to transfer more output gain.
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