US Patent 9774300 Transformer-based doherty power amplifier

Transformer-based Doherty power amplifier (PA). In some embodiments, a Doherty PA can include a carrier amplification path having an output that includes a carrier transformer, and a peaking amplification path having an output that includes a peaking transformer. The Doherty PA can further include a combiner configured to combine the outputs of the carrier and peaking amplification paths into an output node. The combiner can include a quarter-wave circuit implemented between the carrier and peaking transformers.