A multiband coupling circuit including: a number of paths equal to the number of frequency bands, each path having a first terminal and a second terminal; a third terminal and a fourth terminal; a number of distributed couplers equal to the number of paths, all couplers being identical and sized according to the highest frequency band, and each coupler including a first conductive line between first and second ports connected to the first and second terminals of the concerned path, and a second conductive line coupled to the first one between third and fourth ports; a first set of attenuations between the third ports of the couplers and the third terminal of the circuit; and an array of filters between the fourth ports of the coupler and the fourth terminal of the circuit.