A device includes a digital circuit for receiving input signals and Cartesian feedback signals includes a stage for combining the input signals and the feedback signals to generate error signals. The digital circuit is linked via a conversion stage to an analogue circuit suitable for receiving the error signals, and which includes a stage for generating an output signal from the error signals and a stage for generating the feedback signals from the output signal. The digital circuit also includes at least one gain control stage before the combination stage for modifying the gain applied to the input signals.