A satellite-based emission and reception device, intended to receive and to process radiofrequency signals originating from an uplink and then to emit the processed signals on a downlink towards terrestrial users, comprises a power divider, two independent frequency converters and two input demultiplexers connected respectively at the output of the two corresponding frequency converters, each frequency converter being controlled by a dedicated local oscillator, the two local oscillators operating at one and the same frequency, the two input demultiplexers comprising channel filters operating in different, disjoint frequency sub-bands spaced apart in frequency, two adjacent frequency sub-bands being filtered by two channel filters belonging to different input demultiplexers.