Abstract: A microwave antenna element suitable for constituting one of the elements of an array, the antenna element being capable of transmitting or receiving two orthogonally-polarized microwaves. The antenna element is constituted by a cavity containing two orthogonal excitation probes separated by a polarization-selective obstacle forming both a short-circuit plane for the microwave transmitted by the top probe, and also a patch for the microwave transmitted by the bottom probe. Another patch is common to both of the interlaced antennas. A third patch which is polarization-selective in the sense that it is transparent for the microwave transmitted by the bottom probe, may also be provided.