Linearizing device for a high-frequency amplifier with complex non linear coefficients

摘要

1. Linearizing device of a high frequency signal amplifier (12), having complex non-linearity coefficents and susceptible to amplify a multi-tone signal e(t), comprising means to generate form the high frequency signal to be amplified a first and a second signal q(t) and q(t) the spectrum of which comprises lines of adjustable amplitude lying at frequencies corresponding to harmonics of the tone spacing of the high frequency signal to be amplified, separately acting on two distinct parameters of the signal to be amplified, and a predistorsion device (1) to generate from the high frequency signal to be amplified and from the first and second correction signals an input signal h(t) of the amplifier the spectrum of which comprises, in addition to the high frequency lines of the signal to be amplified, correcting lines at the frequencies of the intermodulation products of odd orders, the amplitude of which is adjustable by the combined action on the amplitude adjustments of the lines of the spectrum of the first and second correction signals q(t) and q'(t), these adjustments being performed in order to obtain an elimination of the intermodulation porducts of odd orders located in the neighborhood of the transmission band in the amplified signal, characterized in that the predistorsion device (1) comprises a modulator (2) for modulating the amplitude of the signal to be amplified e(t) by the first correction signal q(t), a suppressed carrier modulator (3) for modulating the signal to be amplified e(t) phase shifted by pi/2 by the second correction signal q'(t), and a summer (5) for summing the signals supplied by these modulators to furnish the input signal of the amplifier (12).