Patent ID: 7042283

Claim:
A high-efficiency linear power amplifier comprising: a digital predistorter for predistorting an input digital transmission signal thereto by use of a power-series model; a digital-analog converter for converting the output from said digital predistorter to an analog signal; an up converting part for frequency-converting the output from said digital-analog converter to a radio-frequency signal; a Doherty amplifier for power-amplifying said radio-frequency signal and for transmitting said power-amplified radio-frequency signal; a pilot signal generator for generating a digital pilot signal; an adder for adding said digital pilot signal to said digital transmission signal and for inputting the added output to said digital predistorter; a pilot signal extractor for extracting a radio-frequency pilot signal from the output from said Doherty amplifier; a down converting part for frequency-converting said extracted pilot signal to a baseband extracted pilot signal; an analog-digital converter for converting said baseband extracted pilot signal to a digital extracted pilot signal; and a control part for detecting an odd-order distortion component from said digital extracted pilot signal and for controlling parameters of said digital predistorter based on the detected odd-order distortion component.