Abstract: The frequency multiplexer device for combining n single signals of bandwidth (B), sampled with a sampling frequency (fa/n), includes a device for performing a Fourier transformation (FFT) of the single signals to obtain complex input signals having imaginary portions and real portions and a number of circuit devices for generating an output signal for multiplexing from the imaginary portion and the real portion of each complex input signal. Each output signal generating device includes respective different chains (111) of serially connected delay elements (110, D) for delaying the real and imaginary portions to form differently delayed imaginary real and signal portions; circuit devices for combining (+) and weighting pairs of the differently delayed real and imaginary signal portions to be weighted with respective weighting factors (.gamma.h(5), -.gamma.h(1), .gamma.h(3)) to form respective weighted combined signals for each different weighting factor.