Patent ID: 6085074
Filing Date: 2000-07-04
Classification: H03F,H04B

Abstract:
A Doherty-type amplifier comprising:a signal splitter having an input that receives a signal of varying amplitude and producing a first amplitude-varying signal and a second amplitude-varying signal;a carrier amplifier stage, coupled to a first output of the signal splitter, applying a first gain to the first amplitude-varying signal to produce a first amplified signal;a peaking amplifier stage, coupled to a second output of the signal splitter, applying a second gain to the second amplitude-varying signal to produce a second amplified signal only when an amplitude of the second amplitude-varying signal exceeds a threshold, the second gain being greater than the first gain and reciprocally related to a ratio of a power of the send amplitude-varying signal to a power of the first amplitude-varying signal; anda signal combiner, coupled to an output of the carrier amplifier stage and an output of the peaking amplifier stage, combining the first amplified signal and the second amplified signal.