Abstract: The invention concerns a method of allocating a respective free radio beam channel to calling and called stations of a satellite telecommunication network. If there is no free channel on a beam forming the coverage including one given station, the method of the invention looks for free channels in each beam adjacent said beam, and allocates one of the adjacent beam free channels to the given station as soon as in an optimal subset of beams comprising all beams using the same channel as the free channel each level of isolation equal to the ratio of an antenna gain of a main lobe of a respective one of the beams of the optimal subset to the sum of the maximal antenna gains of secondary lobes of the other beams is greater than a given threshold.

Abstract: A multifrequency radiating device comprising at least one radiating element (11) of a first type and at least one radiating element (12) of a second type, the elements being associated on a common surface (10) in order to constitute an array antenna. The radiating elements of the first type (16) are elements of the microstrip type and the elements of the second type (19, 20) are elements of the wire type, the radiating elements of the first type (16) acting in a first frequency range and the radiating elements of the second type (19, 20) acting in a second frequency range. The invention is particularly applicable to microwave antennas.

Abstract: A earth station calling another station sends a link setting-up a request to a control station. The control station memorizes in a transformed reference system the contour of a global geographical coverage including all the earth stations together with the earth positions of the latter. Subsequent to the request, the control station simulates the optimum evolution of the radioelectric coverages of the satellite so as to include, both on emitting and receiving, the calling and called stations in respective coverages with guaranteed minimum antenna gains. The total power of the satellite and the positions of the stations are notably considered in this simulation. If the result of simulation is positive, an emission authorization is sent by the control station to the calling station, and satellite antennae are reconfigured by phase shift and power control values emitted by the control station.

Abstract: An offset type active antenna having two reflectors in a periscopic configuration. A radio lens is provided at the focii of the two reflectors. It comprises a collector and a primary array that is considerably larger in size than the collector. The "small" sources of the collector are in a geographically identical one-to-one correspondence with the "big" sources of the primary array, and they are respectively connected together via devices for providing fine phase adjustment.

Abstract: The invention relates to a reconfigurable transmission antenna comprising a reflector (10) for energy focussing, and an array (11) of source elements situated in the focal region of the reflector, so that the electromagnetic field is synthesized in said region, wherein a spot (SPi) is the result of radiation from a number of sources that is fixed and identical for all the spots; any one source participating at any one time in radiating one spot at the most, and high-level switching being used to reconfigure the spots by selecting the sources that participate in a given spot. Application to the space telecommunications field in particular.

Abstract: The present invention relates to a multifrequency antenna comprising a microstrip patch first antenna (10, 11, 12) operating at one or more frequencies, and a second antenna (17) disposed in front of the antenna and using the same radiating surface and operating at a different frequency. The invention is applicable, in particular, to space telecommunications.

Abstract: The invention relates to a space reentry vehicle high-temperature skin antenna comprising a printed antenna embedded in a tile for providing thermal protection, and fed by electromagnetic coupling. The invention is particularly applicable to space telecommunications.

Abstract: An electronically scanned antenna comprising an array (11) of elementary sources, an energy-focusing reflector (10), and feed and control electronics, with the array (11) being situated in the focal zone of the reflector, and in which elementary sources that are not used simultaneously are grouped together in classes (Ci) in which only one source can be active at a time, with all of the sources in each class (Ci) being interconnected by a passive combiner (40) for that class. The invention is applicable in particular to space telecommunications.

Abstract: The present invention relates to an antenna which is electronically reconfigurable in transmission. The antenna comprises an array (11) of elementary sources, an energy-focusing reflector (10), with the array (11) being situated in the focal zone of the reflector, and control and feed electronics, the electronics comprising an amplifier stage (22) constituted by amplifiers (24) and including at least one generalized coupler disposed at the outputs of the amplifiers (24), and beam-forming circuits (20, 21) each corresponding to a transmitted beam, with the amplitude and relative phase of the signals leaving said circuits being controlled by respective adjustable phase shifters and adjustable attenuators. The invention is particularly applicable to space telecommunications.

Abstract: The invention relates to an electronically scanned antenna comprising an array (11) of elementary sources, an energy-focusing reflector (10), and feed and control electronics; the array (11) is situated in the focal zone of the reflector, while the feed and control electronics includes a plurality of attenuator and phase shifter circuits (24) controlled by a control unit (27), with said circuits having their outputs connected to at least one combiner (28). The invention is particularly suitable for space telecommunications.

Abstract: A three-access polarization and frequency duplexing device has in series a common circular waveguide for passing two polarizations of a wave within a low-frequency band and one polarizations of a wave within a high-frequency band, a first access waveguide which opens into the common waveguide and a transition, a secondary rectangular waveguide. The narrow sides of the secondary waveguide are parallel to one polarization of the low-frequency band and the broad sides are parallel to the polarization of the high-frequency band. A second access waveguide is connected to the secondary waveguide at right angles and coupled by a resonant slot. A short-circuit plate performs a short-circuiting function for the high-frequency portion of the wave of the high-frequency band aligned with the second access waveguide. The free end of the secondary waveguide being forms a third access waveguide. The first access waveguide has a filter for selecting a polarization of the wave from the low-frequency band.

Abstract: An antenna pointing device capable of scanning in two orthogonal directions comprises a fixed source (20) emitting a radio beam (21) and associated with a main offset reflector (10) and a secondary offset reflector (11), together with a set of at least three mirrors (14, 15, and 17) including a first mirror (14) aligned with the secondary reflector (11), and in which the second and third mirrors (15 and 17) are fixed to respective rotary drive mechanisms (16 and 18) for rotating them about two axes (.DELTA., .DELTA.') extending in orthogonal directions. The main and the secondary reflectors (10, 11) and the first and the second mirrors (14, 15) are mechanically fixed to one another in order to constitute a moving assembly. The second mechanism (18) drives both the third mirror (17) and said moving assembly (10, 11, 14, and 15).

Abstract: The invention relates to a rotary microwave joint device comprising a main circular waveguide constituted by two portions (10, 11) situated as extensions to each other and rotatable relative to one another about their axis of symmetry, each of said two portions (10, 11) being provided with at least one access which is orthogonal thereto, and mechanical means enabling a circularly polarized wave to be obtained in the main waveguide. The invention is applicable to space telecommunications.