Patent ID: 8314655
Filing Date: 2012-11-20
Classification: H03F,H03G

Abstract:
1. An RF power amplifier module, comprising: a first RF power amplifier circuit operable to amplify an RF transmission input signal of a first frequency band; a second RF power amplifier circuit operable to amplify an RF transmission input signal of a second frequency band; and an output-power controller, wherein the output-power controller includes a first power detector, a second power detector, and an error amplifier, wherein the first power detector detects a level of a first RF transmission signal arising from an output terminal of the first RF power amplifier circuit, wherein the second power detector detects a level of a second RF transmission signal arising from an output terminal of the second RF power amplifier circuit, wherein the error amplifier generates a power control voltage in response to a difference between an external control voltage and a detection output voltage from each of the first and second power detectors, wherein the first and second RF power amplifier circuits each include an amplifier and a controller, wherein the amplifier responds to an RF transmission input signal accepted through an input terminal, generates an RF transmission output signal, and outputs the signal through an output terminal, wherein the controller includes a first control unit and a second control unit, wherein the first control unit responds to an output-power-control voltage supplied to a first input control terminal, generates a first output current, and outputs the first current from a first output control terminal, wherein the second control unit responds to the first output current from the first control unit supplied to an second input control terminal, generates a second output current for deciding a quiescent current of an amplification transistor of the amplifier, and outputs the second current from a second output control terminal, wherein a maximum value of the output-power-control voltage is set to a predetermined voltage value, whereby a maximum value of the first output current arising from the first output control terminal of the first control unit is set to a predetermined current value, wherein the second control unit includes a plurality of MOS transistors operable to respond to the first output current from the first control unit and generate the second output current, and wherein the plurality of MOS transistors of the second control unit respond to the first output current of the first control unit set to the predetermined maximum value, and operate in respective subthreshold regions.