A directional dual distributed coupler including: a first conductive line between first and second ports, intended to convey a signal to be transmitted in a first frequency band; a second conductive line coupled to the first one; a third conductive line between third and fourth ports, intended to convey a signal to be transmitted in a greater frequency band than the first one; a fourth conductive line coupled to the third one; and at least one diplexer connecting, on the side of the second and fourth ports, the respective ends of the second and fourth lines to a fifth port.