Abstract: A radio frequency power amplifier includes a feedback control system coupled to an input signal and a first feedback signal and configured to provide an output; a controlled supply configured to provide power that is controlled in accordance with a signal; and a radio frequency gain stage powered from the controlled supply, driven by the output from the feedback control system, and configured to provide an output signal at the radio frequency to a resonant load, where the first feedback signal corresponds to the output signal. Some embodiments include a sequencer in the feedback control system and others utilize an additional feedback loop to control the power provided by the controlled supply.

Abstract: A radio frequency power amplifier and corresponding methods are arranged and configured to drive or provide a radio frequency signal to a resonant load. The amplifier includes a radio frequency switching stage with an output that is coupled to a resonant circuit and configured to provide an output signal with amplitude modulation corresponding to amplitude modulation of an input signal when powered from a fixed voltage power supply and a feedback control system coupled to the input signal and the output signal. The feedback control system includes a sequencer configured to provide a sequencer output that is used to drive the radio frequency switching stage, where the sequencer output has an OFF state that begins at a variable time corresponding to the input and output signal.