DIGITAL RADIO EQUIPMENT HAVING NEGATIVE FEEDBACK LOOP OF NONLINEAR DISTORTION CORRECTION

摘要

PROBLEM TO BE SOLVED: To provide a new digital radio equipment capable of performing proper phase correction without changing an antenna at a termination resistor on every transmission, even if there is 180-degree phase shift in a carrier between orthogonal modulation and orthogonal demodulation sides.;SOLUTION: In a second loop which outputs a transmission signal to an orthogonal demodulator 17 without passing through a power amplifier 14 using a circuit changing switch 23 provided between an orthogonal modulator 9 and the power amplifier 14, 0 degree or 180 degree shift is detected for phases between in-line components LoI and LodI of a carrier Lo. When 180 degree shift is detected, the phase shift is corrected by a phase correction unit 22, and then it is switched to a first loop which passes through the power amplifier 14 for transmission.;COPYRIGHT: (C)2004,JPO