Alcatel

Alcatel Alsthom Compagnie Generale D'electricite

Jean-Xavier Canonici

Rossano Marchesani

An imbalance estimator for quadrature modulators comprising two mixers to which are applied two carrier signals and to each of which is applied a modulating signal, output signals of said mixers being applied to a combiner to constitute a modulated signal, detects the instantaneous power of the modulated signal. The detected instantaneous power is multiplied by the modulating signals, and the resulting signals are rectified. The rectified signals are rectified to supply signals indicative of the imbalance of the modulator.

Quadrature modulator imbalance estimator and modulator stage using it

A quadrature modulator including two mixers to which two carrier signals are applied and to each of which a modulating signal is applied, output signals of the mixers being applied to a combiner to constitute a modulated signal. A defect estimator for the modulator detects a first signal representative of the instantaneous power of the modulated signal, generates a second signal representative of a reference envelope obtained from the modulating signals, and corrects the amplitude of one of the first and second signals in accordance with the mean amplitude difference observed between this amplitude corrected signal and the other signal. A processor supplies from the observed amplitude difference between the amplitude corrected signal and the other signal, at least one signal relating to the defect.

Growing community of inventors

Neuilly, France

Jean-Xavier Canonici