| 摘要 |
A quadrature modulation error is compensated without providing an additional feedback loop for detecting the quadrature modulation error. An amplifier circuit includes: a quadrature modulator 33; an amplifier 2 that amplifies a quadrature-modulated signal; a distortion compensation section 4 that compensates distortion to be caused in the amplifier based on first compensation coefficients; a quadrature modulation error compensation section 9 that compensates for a quadrature modulation error; an updating section 10b that updates second compensation coefficients for compensating the quadrature modulation error; an error estimation section 10a that estimates an error of the quadrature modulation error; and a prediction section that calculates a prediction value of an output of the amplifier after updating of the second compensation coefficients. The second compensation coefficients are updated based on the estimated error. The prediction value is calculated based on the estimated error and the amplifier output. The distortion compensation section 4 calculates the first compensation coefficient, based on the prediction value. |
