Abstract: The invention concerns an antenna, comprising at least two non-ferrous metal plates, at least one first plate forming a radiating portion and a second plate forming a mass plane, at least one substrate, arranged between the mass plane and the radiating portion, and an excitor of length at least equal to the thickness of the substrate, extending between the mass plane and the radiating portion and connected to the radiating portion, and adapted to supply the antenna, characterised in that the substrate is a dispersive ferromagnetic substrate, called dispersive ferrite presenting, as magnetic features, a high relative magnetic permeability comprised between 10 and 10,000 and a high magnetic loss tangent greater than 0.1, said antenna comprising means for gradually and locally reducing magnetic features of the dispersive ferrite.

Abstract: The invention relates to an antenna structure for transmitting and/or receiving wavelengths of metric frequency or decimetric frequency, characterised in that it comprises n collinear antennas, each antenna comprising a radiating portion comprising a first succession of i coaxial radiating elements about a first axis alternating with at least an additional succession of i radiating elements about another axis, each antenna being independently powered by a coaxial cable, each antenna comprising at least one lower quarter-wave trap and at least one upper quarter-wave trap, at least a first antenna comprising at least one hollow core being configured to receive a coaxial cable intended for powering of another antenna collinear with the first antenna, at least one intermediate quarter-wave trap being arranged between two consecutive collinear antennas around a coaxial cable, and a terminal element.

Abstract: The disclosure relates to a ferrite antenna comprising at least one main contour, comprising at least one first winding referred to as main winding, at least one first ferromagnetic rod referred to as main ferromagnetic rod and a tuning system, each main winding being wound around a main ferromagnetic rod and connected to the tuning system comprising a capacitor connected in parallel with the main winding. The ferrite antenna further comprises a non-resonant secondary contour, comprising a secondary winding separated electrically from each main winding and a secondary ferromagnetic rod around which the secondary winding is wound, and each main ferromagnetic rod and the secondary ferromagnetic rod are arranged parallel to one another so as to make it possible for a magnetic coupling of each main winding with the secondary winding.

Abstract: The invention concerns an antenna, comprising at least two non-ferrous metal plates, at least one first plate forming a radiating portion and a second plate forming a mass plane, at least one substrate, arranged between the mass plane and the radiating portion, and an excitor of length at least equal to the thickness of the substrate, extending between the mass plane and the radiating portion and connected to the radiating portion, and adapted to supply the antenna, characterised in that the substrate is a dispersive ferromagnetic substrate, called dispersive ferrite presenting, as magnetic features, a high relative magnetic permeability comprised between 10 and 10,000 and a high magnetic loss tangent greater than 0.1, said antenna comprising means for gradually and locally reducing magnetic features of the dispersive ferrite.

Abstract: The invention relates to an antenna structure for transmitting and/or receiving wavelengths of metric frequency or decimetric frequency, characterised in that it comprises n collinear antennas, each antenna comprising a radiating portion comprising a first succession of i coaxial radiating elements about a first axis alternating with at least an additional succession of i radiating elements about another axis, each antenna being independently powered by a coaxial cable, each antenna comprising at least one lower quarter-wave trap and at least one upper quarter-wave trap, at least a first antenna comprising at least one hollow core being configured to receive a coaxial cable intended for powering of another antenna collinear with the first antenna, at least one intermediate quarter-wave trap being arranged between two consecutive collinear antennas around a coaxial cable, and a terminal element.

Abstract: The invention relates to a surface wave antenna system, comprising at least one antenna that is electrically short in the vertical plane, with vertical or elliptic polarization and emitting a radiation, said antenna being linked to a conducting medium exhibiting a substantially horizontal surface. The antenna system being characterized in that it comprises furthermore at least one parasitic wire extending in a direction substantially parallel to the surface of the conducting medium, electrically insulated from each antenna, and arranged in the vicinity of at least one antenna in such a way as to be able to radiate by virtue of the current induced by said radiation of this antenna. The invention makes it possible to combine the resultants of each radiating element in such a way as to control the radiation pattern in the vertical plane.

Abstract: The disclosure relates to a ferrite antenna comprising at least one main contour, comprising at least one first winding referred to as main winding, at least one first ferromagnetic rod referred to as main ferromagnetic rod and a tuning system, each main winding being wound around a main ferromagnetic rod and connected to the tuning system comprising a capacitor connected in parallel with the main winding. The ferrite antenna further comprises a non-resonant secondary contour, comprising a secondary winding separated electrically from each main winding and a secondary ferromagnetic rod around which the secondary winding is wound, and each main ferromagnetic rod and the secondary ferromagnetic rod are arranged parallel to one another so as to make it possible for a magnetic coupling of each main winding with the secondary winding.

Abstract: The invention relates to a surface wave antenna system, comprising at least one antenna that is electrically short in the vertical plane, with vertical or elliptic polarization and emitting a radiation, said antenna being linked to a conducting medium exhibiting a substantially horizontal surface. The antenna system being characterized in that it comprises furthermore at least one parasitic wire extending in a direction substantially parallel to the surface of the conducting medium, electrically insulated from each antenna, and arranged in the vicinity of at least one antenna in such a way as to be able to radiate by virtue of the current induced by said radiation of this antenna. The invention makes it possible to combine the resultants of each radiating element in such a way as to control the radiation pattern in the vertical plane.

Abstract: The antenna comprises a metal excitation loop (B1) to be positioned at a height (h) of at least about 1 above the surface (SM) of a conducting medium (M) and a supply means (A, L1n) to be connected to the conducting medium. The perimeter of the loop is about one half of the operating wavelength, namely ?/2, in length. The loop comprises two approximately parallel portions (I1p-I1n, S1) which are at most about ?/50 apart and are capable of extending approximately parallel to said surface in a plane approximately perpendicular to said surface, currents of opposite direction flowing through said portions. The closest portion to said surface includes an aperture between ends (E1p, E1n) of the loop that are connected to the supply means. The antenna is better protected from space waves and it can be reduced in size by being folded up.