A calibration device is coupled to a balanced circuit device including first and second outputs provided with first and second load impedances. The calibration device includes an adjusting circuit to adjust the first and second load impedances into a load imbalance for linearization. A coupling circuit is inserted between the adjusting circuit and the first and second outputs to selectively couple the adjusting circuit to one of the first and second outputs, so that the adjusting circuit is coupled in parallel either to the first load impedance or to the second load impedance.