Quadrature modular with adaptive suppression of carrier leakage

摘要

A carrier leakage suppression circuit is disclosed which adaptively suppresses carrier leakage in a signal processing device which modulates a carrier signal with an in-phase baseband signal and a quadrature baseband signal to generate a radio frequency (RF) output signal. The carrier leakage suppression circuit operates by imparting a first signature to the in-phase baseband signal and a second signature to the quadrature baseband signal prior to modulation of the carrier signal. In-phase and quadrature carrier leakage components in the RF output signal are isolated and measured by respectively correlating the RF output signal with the first and second signatures. An in-phase offset and a quadrature offset are generated as a function of the measurement of the in-phase and quadrature carrier leakage components. The in-phase baseband signal is combined with the in-phase offset and the quadrature baseband signal is combined with the quadrature offset to thereby suppress carrier leakage.