DUAL MODE POWER AMPLIFIER

摘要

A power amplifier (202, 330) is configured to operate in a first gain mode and a second gain mode. A first power amplifier input stage (208, 308) has an input and an output. A second power amplifier input stage (210, 310) has an input and an output, where the output of the second power amplifier input stage is coupled to the output of the first power amplifier input stage. The first input stage is turned on in response to a first bias voltage (222, 322) in the first gain mode and the second input stage is turned on in response to a second bias voltage (224, 324) in the second gain mode. Alternatively, a first input stage (208, 308) and an intermediate stage (212, 312) can be switched off by turning off their respective bias voltages (222, 322, 226, 326), and a second input stage (210, 310) can be switched on by turning on its respective bias voltage (224, 324); the intermediate stage and the second input stage sharing a common output.