A method for linearizing an amplifier to produce an amplified output signal from a set of carrier frequencies is disclosed in which a set of digital baseband signals corresponding to the set of carrier frequencies are combined to produce an extended digital baseband signal. Look-up values are then derived from the power values of the extended digital baseband signal and applied to a look-up table to obtain predistortion values. One or more predistorted signals are then produced by complex mixing the predistortion values with one of the set of extended digital baseband signals. The predistorted signal(s) are then amplified to produced an output signal which is linearly related to the set of digital baseband signals. In one embodiment, linearly combining the set of digital baseband signals includes complex mixing individual digital baseband signals of the set of digital baseband signals with trigonometric signals to produce complex mixed signals and adding the complex mixed signals to produce the extended digital baseband signal. Producing one or more predistorted signals may include upconverting the predistorted signals synchronously when the predistorted signals are a complex mixing of the predistortion values and the set of digital baseband signals. In one embodiment, the look-up table is a function of pre-measured calibration data.