摘要 |
The invention is related to a balanced cuber based predistortion circuit for predistorting an input signal (vin), comprising a squarer (11) to produce a second order signal and signal dividing means (10', 14') for dividing the input signal and second order signal into differential signals. To produce a third order signal, the input signal and second order signal are mixed in multipliers (15, 16) and the output signals of the multipliers are combined in order to eliminate undesired components. According to the invention, the squarer also includes differential signal handling and combining means (12, 13), advantageously a push-push frequency doubler to produce a second order signal using differential signals. The phase (17) and amplification (18) of the third order signal are adjusted in order to produce a distortion compensation signal, and the input signal (vin) and distortion compensation signal are combined (19) to produce a predistorted output signal (v1). <IMAGE> |