Abstract: A half-wave printed “patch” antenna includes, symmetrically with respect to a plane of symmetry of the antenna perpendicular to faces of the antenna, a dielectric substrate and two conductive layers on respective faces of the substrate. One face of the substrate includes a raised portion extending lengthwise of the plane of symmetry and one of the conductive layers extends over and along said raised portion. Consequently, the antenna has a small size, combined with a more open radiation diagram. The antenna includes only one raised portion for linear polarization, or two raised portions or a raised portion with axial symmetry for crossed polarizations.

Abstract: A helical antenna includes at least a helix consisting of at least two radiating strands, at least one of the strands consisting of at least two segments, the winding angles of at least two of the segments being different and randomly or pseudo-randomly determined with global optimising means.

Abstract: The printed antenna is compact and comprises, superposed by dielectric layers, two feed lines having perpendicular microstrips, a ground plane, a first radiating element including a plurality of conductive strips perpendicular to a first coupling slot formed in the ground plane, and a second radiating element superposed on the first element and including a plurality of conductive strips crossing by superposition the first strips and perpendicular to a second coupling slot formed in the ground plane. For example, the elements radiate in the DCS-1800 and GSM radiotelephone frequency bands with perfectly orthogonal fields.

Abstract: The invention concerns a helical antenna, comprising at least a helix consisting of at least two radiating strands, at least one of said strands consisting of at least two segments, the winding angles of at least two of said segments being different and randomly or pseudo-randomly determined with global optimising means.

Abstract: The invention relates to a helix antenna with integrated duplexing means comprising two decoupled coaxial helices, each formed by radiating strands (111 to 114) printed on a substrate, each of the helices being associated with an independent and miniaturized structure (12, 13, 14) for the wideband supply of the radiating strands, the supply structures being printed on the corresponding substrate and comprising at least one hybrid coupler (12, 13, 14) made out of semi-localized elements so as to reduce the dimensions thereof. Advantageously, the helices are wound in opposite directions of winding (17) and their points of excitation are offset with respect to each other, in a plane perpendicular to the axis of the helices. Corresponding methods of manufacture are used to form the helix antenna.

Abstract: A half-wave printed “patch” antenna includes, symmetrically with respect to a plane of symmetry of the antenna perpendicular to faces of the antenna, a dielectric substrate and two conductive layers on respective faces of the substrate. One face of the substrate includes a raised portion extending lengthwise of the plane of symmetry and one of the conductive layers extends over and along said raised portion. Consequently, the antenna has a small size, combined with a more open radiation diagram. The antenna includes only one raised portion for linear polarization, or two raised portions or a raised portion with axial symmetry for crossed polarizations.

Abstract: The printed antenna is compact and comprises, superposed by dielectric layers, two feed lines having perpendicular microstrips, a ground plane, a first radiating element including a plurality of conductive strips perpendicular to a first coupling slot formed in the ground plane, and a second radiating element superposed on the first element and including a plurality of conductive strips crossing by superposition the first strips and perpendicular to a second coupling slot formed in the ground plane. For example, the elements radiate in the DCS-1800 and GSM radiotelephone frequency bands with perfectly orthogonal fields.

Abstract: An antenna receives beams from telecommunication satellites in geostationary orbit close to the equator. The continuous concave reflecting surface of the reflector of the antenna has an equation deduced from a paraboloid by adding thereto the equation of a correction surface comprising a second order polynomial and a sum of N(2N−1) terms depending on distances between the projection of any point on the reflecting surface and N(2N−1) control points of a grid extending over a plane perpendicular to the plane of symmetry. The angular separation of the primary sources on a circular support with an inclination different from the angle of offset is less than approximately 3° for an aperture of more than 50°.

Abstract: A resonant helix antenna comprising at least one helix formed by at least two radiating strands (111 to 114) printed on a substrate. This antenna comprises a miniaturised structure for the wideband supply of the radiating strands that is printed on the substrate and comprises at least one hybrid coupler made out of semi-localised elements so as to reduce the dimensions thereof. In the case of a quadrifilar helix, formed by four radiating strands, the supply structure comprises three hybrid couplers, for example in the form of a first 180° hybrid coupler (12) associating a supply input and/or output (17) of the antenna with two intermediate outputs and/or inputs (18, 19) phase-shifted by 180° and two 90° hybrid couplers (13, 14) each associating one of the intermediate outputs and/or inputs of the hybrid coupler with one of the ends of two of the radiating strands.

Abstract: The invention relates to an antenna source transmitting and receiving polarized microwaves, the source including a transducer for separating the transmission signals from the reception signals, the frequencies of the transmission signals being different from the frequencies of the reception signals. The connection between the transducer and the radiating element of the antenna is such that it maintains the polarization states of the signal received by the radiating element and of the signal transmitted to said radiating element. The transducer comprises a square-section waveguide, one end of which is connected to the radiating element, the other end being connected to the transmission path, the received signals being conveyed by the side faces of the waveguide. This source makes it possible to transmit and to receive in the enlarged C band, i.e. 3.4 GHz to 4.2 GHz on reception, and 5.85 GHz to 6.65 GHz on transmission.