An antenna structure for telecommunications, in particular by satellite, comprising: • an emitting surface comprising at least one set of a plurality of elementary emitting antennas forming an array, and • a receiving surface comprising at least one set of a plurality of elementary receiving antennas forming an array, the antenna structure being characterized in that it is electronically-scanned and that it is realized on single-layer substrate comprising a rear side at the ground plane and that it comprises coupling, power supplying and phase shifting devices inserted on the rear side, and • at least one elementary emit antenna comprising two generally circular patches (14Tx, 16Tx) that are at least partially superimposed, said at least one elementary emitting antenna being dimensioned to emit at least one electromagnetic wave having a frequency comprised between 27 GHz and 31 GHz, and • at least one elementary receiving antenna comprising two generally circular patches (14Rx, 16Rx) that are at least partially superimposed, said at least one elementary receiving antenna being dimensioned to receive at least one electromagnetic wave having a frequency comprised between 17.3 GHz and 21.2 GHz; and in that the emitting surface is for circular polarization in a first direction, and the receiving surface is for circular polarization in a second direction opposed to the first direction, and in that: • each patch (14Tx, 16Tx) of said at least one elementary emitting antenna has a center, said elementary emitting antenna comprising two power supply ports (28Tx, 30Tx) able to power one of the two patches (14Tx, 16Tx), each port (28Tx, 30Tx) being in an angular sector having an angle relative to the center of the powered patch (14Tx, 16Tx) smaller than 180°, and/or • each patch (14Rx, 16Rx) of said at least one elementary receiving antenna has a center, said elementary receiving antenna comprising two power supply ports (28Rx, 30Rx) able to power one of the two patches (14Rx, 16Rx), each port (28Rx, 30Rx) being in an angular sector having an angle relative to the center of the powered patch (14Rx, 16Rx) smaller than 180°, and in that • the two patches (14Tx, 16Tx) of said at least one elementary emitting antenna are spaced apart in a first direction by a distance (ezTx) comprised between 0.75 millimeters (mm) and 1.5 mm, and/or • the two patches (14Rx, 16Rx) of said at least one elementary receiving antenna are spaced apart in a first direction by a distance (ezRx) comprised between 0.75 millimeters (mm) and 1.5 mm, and in that • the diameters (d1Tx, d2Tx) of the two patches (14Tx, 16Tx) of said at least one elementary emitting antenna are identical, and/or • the diameters (d1Rx, d2Rx) of the two patches (14Rx, 16Rx) of said at least one elementary receiving antenna are identical. • an emitting surface comprising at least one set of a plurality of elementary emitting antennas forming an array, and • a receiving surface comprising at least one set of a plurality of elementary receiving antennas forming an array, • at least one elementary emit antenna comprising two generally circular patches (14Tx, 16Tx) that are at least partially superimposed, said at least one elementary emitting antenna being dimensioned to emit at least one electromagnetic wave having a frequency comprised between 27 GHz and 31 GHz, and • at least one elementary receiving antenna comprising two generally circular patches (14Rx, 16Rx) that are at least partially superimposed, said at least one elementary receiving antenna being dimensioned to receive at least one electromagnetic wave having a frequency comprised between 17.3 GHz and 21.2 GHz; • each patch (14Tx, 16Tx) of said at least one elementary emitting antenna has a center, said elementary emitting antenna comprising two power supply ports (28Tx, 30Tx) able to power one of the two patches (14Tx, 16Tx), each port (28Tx, 30Tx) being in an angular sector having an angle relative to the center of the powered patch (14Tx, 16Tx) smaller than 180°, and/or • each patch (14Rx, 16Rx) of said at least one elementary receiving antenna has a center, said elementary receiving antenna comprising two power supply ports (28Rx, 30Rx) able to power one of the two patches (14Rx, 16Rx), each port (28Rx, 30Rx) being in an angular sector having an angle relative to the center of the powered patch (14Rx, 16Rx) smaller than 180°, • the two patches (14Tx, 16Tx) of said at least one elementary emitting antenna are spaced apart in a first direction by a distance (ezTx) comprised between 0.75 millimeters (mm) and 1.5 mm, and/or • the two patches (14Rx, 16Rx) of said at least one elementary receiving antenna are spaced apart in a first direction by a distance (ezRx) comprised between 0.75 millimeters (mm) and 1.5 mm, and • the diameters (d1Tx, d2Tx) of the two patches (14Tx, 16Tx) of said at least one elementary emitting antenna are identical, and/or • the diameters (d1Rx, d2Rx) of the two patches (14Rx, 16Rx) of said at least one elementary receiving antenna are identical.