A system for amplifying signals generated by a unit for generating signals of a satellite, the system including: a first pathway including a first bandpass digital filter with finite impulse response and a first digital/analog converter; frequency transposition means; an amplifying device; a second pathway including a second bandpass digital filter with finite impulse response; gain means disposed at the output of said second digital filter, a phase-slaved numerically-controlled oscillator, and a second digital/analog converter; and a recombiner device for summing the signals of said first and second pathways.