ANALOG ADAPTIVE PREDISTORTER FOR POWER AMPLIFIER HAVING DIODE HAVING VARIABLE RESISTANCE

PURPOSE: An analog adaptive predistorter for a power amplifier is provided to improve an efficiency and a cost of the power amplifier by varying a resistance of a diode according to an environmental change of the power amplifier. CONSTITUTION: An analog adaptive predistorter for a power amplifier includes an intermodulation distortion generator(110), an intermodulation distortion varying circuit(120), and a bias portion(130). The intermodulation distortion generator generates a mixed distortion signal having a high frequency input signal together with a mixed distortion signal. The intermodulation distortion varying circuit includes a transmission line, a second capacitor, and a first diode. An end of the transmission line is coupled with the intermodulation distortion generator via a first capacitor. The second capacitor connects the other end of the transmission line to the intermodulation distortion generator in series. The first diode is coupled with the transmission line in parallel and has a resistance varying according to a bias voltage. The bias portion applies a direct current bias voltage which is adjusted by an environmental change of the power amplifier to the first diode.