Abstract: The elementary antenna 1 includes: two cross-shaped slots 32, 33 defining four half-slots; for each half-slot, excitation striplines 41, 42, the first stripline 41 being connected to a first via 61 and the second stripline 42 being connected to a second via 62; an integrated circuit 70 delivering a plurality of ports; for each half-slot, tracks for feeding the strips, the first track 51 running from a first port 71 to the first via 61 and the second track 52 running from a second port 72 to the second via 62, the first and second ports being two successive ports of the integrated circuit, differentially connected to a transmitter/receiver channel by first and second power lines situated inside the integrated circuit, the lines and tracks running so that there is no crossing of the respective routes thereof.

Abstract: This elementary antenna includes a cavity delimited by front and rear faces and side walls, the front face being provided with first and second slots arranged in a cross, so that, when the cavity operates in a TE210 mode, a wave polarized perpendicularly to the first slot is emitted and when the cavity operates in a TE120 mode, a wave polarized perpendicularly to the second slot is emitted.