Cartesian digital power amplifier using coordinate rotation

Abstract

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.

Dependencies are inferred from the claim text.