Abstract: An antenna for cellular telephone communications systems, particularly intended for base stations (RPF) of DECT standards, which is able to search for the best path to the user, is formed as a multimode, adaptive, dual antenna, apt to take up both a narrow lobe configuration, with variable orientation on a horizontal plane, and an omnidirectional configuration on a horizontal half-plane, the two antennas composing said dual antenna being similar, integrated onto the same dielectric substrate, and working simultaneously with two different roles (traffic support; search for optimal orientation), said roles being exchanged at every receipt-transmission cycle.