Patent ID: 8005445

Claim:
An RF power amplifying device constituted as a balanced amplifier comprising: a first RF power amplifier; a second RF power amplifier; first phase shifters arranged on input sides of the first RF power amplifier and the second RF power amplifier; second phase shifters arranged on output sides of the first RF power amplifier and the second RF power amplifier; a power divider that responds to an RF signal input supplied to an RF signal input terminal and supplies first and second outputs thereof to respective inputs of the first phase shifters, a power combiner that combines an output of the first RF power amplifier and an output of the second RF power amplifier transmitted through the second phase shifters; and an adder, wherein the first and second RF power amplifiers respectively amplify the first and second outputs of the power divider transmitted through the first shifters, wherein the RF power amplifying device further includes: a first power level detector, an input of which is supplied with the output of the first RF power amplifier; and a second power level detector, an input of which is supplied with the output of the second RF power amplifier, and wherein an output of the first power level detector and an output of the second power level detector are supplied to the adder, and wherein a level of RF transmitting power obtained at an output of the power combiner is controlled by a detected signal from an output of the adder.