Abstract: The radiating portion of the antenna is formed from two similar radiating doublets (1,3; 2,4) which are located in a single plane and are orthogonal, with the slots between driven elements of the doublets crossing one another at the center (C) of the unit antenna.The two doublet modules (1,3; 2,4) are associated with the central conductors of three-plate lines which are orthogonal, with their extensions crossing one another beneath the center (C) of the antenna. Each three-plate line consists of the plates (1,3; 2,4) of a doublet, on the one hand, a reflector, on the other hand, and between the plates and the reflector, the central conductor. The reflector is common to the two doublets.

Abstract: The invention relates to a plane periodic antenna, wherein it comprises a conductive plate having radiating elements formed from two lines of flat teeth, whereof the dimensions are deduced from one another on the basis of a homothetic transformation of ratio .tau. and expansion pole O, the teeth of one of the two lines being inserted between the teeth of the other line and the end of one given tooth being separated from the edge of the plate located between two teeth of the other line by a predetermined gap, a supply line place in a plane close to that of the plate making it possible to supply the teeth, from the predetermined gap, a ground plane located at a distance from each tooth varies as a function of the wavelength of each tooth.

Abstract: Coaxial filter having at least one of the internal and external conductors which is divided into sections (S.sub.1 to S.sub.4) separated by breaks having to form of annular slits whose thickness is very slight in relation to the wavelength.Each section comprises at least one reactive tuning element such as an open or short-circuited coaxial line portion and at least one switch element located in the vicinity of the corresponding break in order selectivity to short-circuit the said break or bring about the insertion of the corresponding reactive tuning element in response to electronic control devices.Application to telecommuncations.

Abstract: The invention relates to doublet plates and the method of making them so t they may operate at very high frequencies.

Abstract: A folded back doublet antenna including two symmetrical half-plates separd at their one ends by a cut, a long, continuous plate separated from one side of each of the half-plates by a gap, linking sections joining the other external ends of the half-plates to respective ends of the continuous plate, and a line feeding the antenna in the vicinity of the cut and extending along the axis of symmetry of the half-plates. The half-plates have a common width, which is much larger than the width of the continuous plate. The half-plates constitute an input side and the continuous plate constitutes a folded back side.

Abstract: A thick folded doublet antenna, the diameter of the current-receiving wire of which is on the order of ten times greater than that of the folded wire, the current-receiving wire comprising two half-wires of exterior symmetrical cylindrical form terminating at the center in two opposed frusto-conical portions, the small bases of which are close to each other, a coaxial conductor having an impedance of approximately 50 ohms extending axially through one of the half-wires, characterized in that the central conductor of the coaxial line is extended across the space between the bases of the frusto-conical portions and penetrates coaxially into a bore in the other half-wire, the central conductor being insulated from the other half-wire, the length of penetration of the central conductor being very short, and the coaxial line being supplied with signals at frequencies whose wavelengths are approximately six times the total height of said doublet antenna.

Abstract: A thick folded dipole having an operating frequency which is far less than he first resonance frequency. The dipole includes a folded strand and a thick fed strand having a diameter which is about ten times greater than the diameter of the folded strand. The fed strand comprises two spaced apart cylindrical half strands having ends in the form of conical frustums and coaxial bore holes. A center conductor of a coaxial cable extends through the folded strand, the bore hole of one half strand, the space between the half strands and into the bore hole of the other half strand. Symmetrical spaced apart short circuits for matching the radiation impedance of the dipole by varying the distance between the short circuits are provided between the fed strand and the folded strand. In another embodiment there is disclosed a thick folded half dipole including a folded half strand and a thick fed cylindrical half strand.