Crossed polarization same-zone two-frequency antenna for telecommunications satellites

Claim 1

In a crossed polarization same-zone two-frequency antenna for telecommunications satellites, the antenna being of the type comprising a parabolic reflector having a concave face, an apex S, a main axis A-A', an elliptical periphery, with a major axis Dx 1 and a minor axis Dy 1 , and a focus F and a primary source of spherical electromagnetic waves having high and low frequency components placed at the focus F of the parabolic reflector, the improvement wherein said reflector further comprises; a first grating of conductor wires fixed to the concave face of the reflector and forming a first reflecting surface, said first grating having the conductor wires extending along lines parallel to each other and in parallel with a plane defined by the main axis of the paraboloid, and the major axis of said elliptical periphery of said paraboloid, and a second grating of short conductor wires orthogonal to the conductor wires of the first grating, said second grating being lcoated within the elliptical periphery of the first grating of conductor wires said second grating being fixed on said concave face and intersecting said first grating conductor wires to form a second reflecting surface having an elliptical periphery with a major axis Dx 2 which is less than DX 1 and with a minor axis Dy 2 which is less than Dy 1 , the first grating also having a periphery in the form of an ellipse and the centers of the ellipses formed by the peripheries of each of the reflecting surfaces being common, and the sizes of the major and minor axes of the ellipses of the two reflecting surfaces formed by the two gratings of conductors being such as to obtain the same coverage zone for the high frequency wave component as for the low frequency wave component.