Dynamically biased amplifier

A method for operating a radio frequency (RF) circuit, comprising:

• amplifying a first signal via a first amplifier circuit;
• outputting, via a first bias voltage generator that comprises a first replica circuit coupled to a second replica circuit, a first bias voltage based on a comparison between a first voltage and a second voltage associated with the first replica circuit;
• and
• feeding, to the first amplifier circuit via a second bias voltage generator, a second bias voltage that is based on the first bias voltage and one or more characteristics of the first signal, wherein the second bias voltage generator is coupled to the first bias voltage generator and selectively coupled to the first amplifier circuit.

A radio frequency (RF) circuit, comprising:

• a transceiver comprising:
• a Doherty amplifier comprising a first amplifier circuit and a second amplifier circuit, wherein the first amplifier circuit is configured to amplify a signal;
• a first bias voltage generator configured to output a first bias voltage based on a comparison between a first voltage and a second voltage associated with the first amplifier circuit;
• and
• a second bias voltage generator coupled to the first bias voltage generator and selectively coupled to the first amplifier circuit, wherein the second bias voltage generator is configured to feed, to the first amplifier circuit, a second bias voltage that is based on the first bias voltage and one or more characteristics of the signal.