Antenna includes at least one first resonant cavity and a second resonant cavity, each resonant cavity being closed by a base at one end and including a radiating element superimposed on the base of the resonant cavity, the radiating element of the first cavity being able to transmit a signal on a first frequency band and the radiating element of the second cavity being able to transmit a signal on a second frequency band separate from the first frequency band, characterized in that a first distance between the base and radiating element of the first cavity differs from a second distance between the base and radiating element of the second cavity.