Patent ID: 6744315
Filing Date: 2004-06-01
Classification: H03F

Abstract:
A transmission amplifier having a distortion compensator for compensating for distortion of an amplifier by updating distortion compensation coefficients so as to null a difference between a transmit signal and a feedback signal, and subjecting the transmit signal to distortion compensation processing using the distortion compensation coefficients; an amplifier for amplifying the transmit signal that has undergone distortion compensation; a feedback unit for feeding an output signal from the amplifier back to an arithmetic unit that calculates the difference in the distortion compensator; and a delay circuit for inputting the transmit signal to the arithmetic unit upon delaying the transmit signal for a delay time equivalent to time required for the feedback signal to arrive at the arithmetic unit, said transmission amplifier comprising:a storing unit for storing, in advance, a delay time TDS of the feedback signal at time of stand-alone operation of the transmission amplifier, and a delay time difference &Dgr;T, which is the difference between delay times of the feedback signal at time of stand-alone operation and at time of parallel operation of the transmission amplifier, or (TDS+&Dgr;T); and a delay-time setting unit for setting the delay time TDS in said delay circuit at the time of stand-alone operation and setting (TDS+&Dgr;T) in said delay circuit at the time of parallel operation.