Patent ID: 8879666

Claim:
A RF power amplifier, comprising: an adder circuit, having a first ratio and a second ratio, receiving a reference voltage and a feedback voltage so as to output an adder voltage after an operation, wherein the feedback voltage is a voltage with a negative temperature coefficient, and the reference voltage is a sum of a first voltage with a positive temperature coefficient and a second voltage with a negative temperature coefficient, and the adder voltage is a sum of the reference voltage multiplied by the first ratio and the feedback voltage multiplied by the second ratio; an output-stage circuit, coupled to the adder circuit, and used for providing the feedback voltage; and a differential circuit, electrically coupled to the adder circuit, having a first multiplier factor, making the adder voltage received be multiplied with the first multiplier factor so as to provide the output voltage to the output-stage circuit; wherein when the reference voltage is a voltage with a zero temperature coefficient, an input current will be a current with a zero temperature coefficient; or, when the reference voltage is a voltage with a positive temperature coefficient and a ratio constant of an input current to an output current of the output-stage circuit has a characteristic of negative temperature coefficient, the output current is a current with a zero temperature coefficient.