Multiple-state, switch-mode power amplifier systems and methods of their operation

摘要

An embodiment of an amplifier includes N ( N >1) switch-mode power amplifier (SMPA) branches. Each SMPA branch includes two drive signal inputs and one SMPA branch output. A module coupled to the amplifier samples an input RF signal, and produces combinations of drive signals based on the samples. When an SMPA branch receives a first combination of drive signals, it produces an output signal at a first voltage level. Conversely, when the SMPA branch receives a different second combination of drive signals, it produces the output signal at a different second voltage level. Finally, when the SMPA branch receives a different third combination of drive signals, it produces the output signal at a voltage level of substantially zero. A combiner combines the output signals from all of the SMPA branches to produce a combined output signal that may have, at any given time, one of 2* N +1 quantization states.