An apparatus includes first through fourth circuits. The first circuit determines a region of an input signal. The region is one of a plurality of regions. The second circuit generates a rotated input signal by rotating the input signal by a first angle according to the region. The third circuit phase shifts a carrier signal by a second angle according to the region. A fourth circuit amplifies the phase shifted carrier signal according to the rotated input signal. A method comprises determining a region according to a phase angle of an input signal, determining a rotation angle according to the region, generating a rotated carrier signal according to a carrier signal and the rotation angle, generating a rotated input signal according to the input signal and the negative of the rotation angle, and amplifying the rotated carrier signal according to the rotated input signal.