Patent ID: 7515650

Claim:
A quadrature modulation compensation signal processor that converts an input signal to an output signal, where the output signal includes an in-phase output signal and a quadrature-phase output signal, in order to compensate for gain and phase imbalance in a quadrature modulator in a plurality of frequencies, comprising: a first digital filter configured to receive an in-phase portion of the input signal and to generate a first in-phase portion of the output signal, wherein the first digital filter is configured to compensate for an in-phase to in-phase portion of the gain and phase imbalance of the quadrature modulator; a second digital filter configured to receive a quadrature-phase portion of the input signal and to generate a second in-phase portion of the output signal, wherein the second digital filter is configured to compensate for a quadrature-phase to in-phase portion of the gain and phase imbalance of the quadrature modulator; a third digital filter configured to receive an in-phase portion of the input signal and to generate a first quadrature-phase portion of the output signal, wherein the third digital filter is configured to compensate for an in-phase to quadrature-phase portion of the gain and phase imbalance of the quadrature modulator; a fourth digital filter configured to receive a quadrature-phase portion of the input signal and to generate a second quadrature-phase portion of the output signal, wherein the fourth digital filter is configured to compensate for a quadrature-phase to quadrature-phase portion of the gain and phase imbalance of the quadrature modulator; a first summing circuit configured to combine the first and the second in-phase portions of the output signal to generate the in-phase output signal; and a second summing circuit configured to combine the first and the second quadrature-phase portions of the output signal to generate the quadrature-phase output signal.