摘要:
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.
摘要:
The invention provides a multibeam antenna comprising: an array 11 of N.sub.e elementary sources 31; energy-focusing optical means comprising a reflector 10 or a lens; the array being situated in the focal zone of said focusing means: and a feed and control circuit cooperating with the N.sub.e primary sources 31 to produce N.sub.b beams each generated from a subgroup of the primary sources, some of which are shared between overlapping beams; the feed and control circuit comprising phase shifter means and attenuator means, said means being organized in N.sub.e feed channels for said N.sub.e primary sources, each feed channel including specific means for acting on the phase and the amplitude of an excitation signal in each feed channel; wherein each required beam is generated by the multibeam antenna solely by acting on the phase and the amplitude of the excitation delivered to each elementary source forming a portion of said beam; and wherein the number of sources N.sub.i contributing to a beam i, 1.ltoreq.i.ltoreq.N.sub.b, varies and is determined as a function of the characteristics desired for said beam i. The antenna is applicable to satellite telecommunications, in particular for on-board antennas of high capacity.
摘要:
A method and a system for locating ground equipment transmitting signals to a geostationary satellite, the method and the system being based on identifying the arrival directions of such signals within the coverage zone of the satellite. In the method, the arrival directions of the signals are identified by using a beam-forming active-module array antenna system on board the satellite, the system being controlled to define simultaneous beams in the radiation pattern of the antenna, the beams being superposed on one another with small offsets, the superposed beams corresponding to a limited analysis zone being illuminated within the coverage zone of the satellite, the system further being associated with a digital processing program which identifies the arrival directions of the signals which are received in the analysis zone.
摘要:
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.
摘要:
A flat scanning antenna comprises at least one slotted waveguide array comprising two dielectric substrates, one superposed above the other. The two substrates comprise the same number of waveguides, which are in mutual correspondence and communicate between them, pairwise, via corresponding coupling slots. Each waveguide of the upper substrate further includes a plurality of radiating slots, all the radiating slots being mutually parallel and oriented in the same direction and each waveguide of the lower substrate includes an individual internal supply circuit comprising an individual phase-shift/amplification electronic circuit.
摘要:
The invention relates to a multiplexing device comprising a data compressor. The compressed data block leaving said compressor occupies a particular bandwidth. According to the invention, a bandwidth prediction unit calculates said bandwidth and deduces from it the available bandwidth for conveyance in a time space dedicated to Internet traffic. The invention also relates to a multiplexing device and a multiplexing/demultiplexing system. Particular application in a satellite telecommunication system.
摘要:
The invention relates to a receiving antenna for satellite telecommunications. More specifically, the invention relates to an active antenna comprising a network of elementary sources which is positioned at the focal point of a focusing reflector. According to the invention, said network of sources is disposed on a more or less spherical, concave surface S. The aforementioned arrangement can be used to: (i) improve the efficiency of the optics and (ii) enable the use of polarisation duplexers behind surface S in order to increase the spectral efficiency of the antenna.
摘要:
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.
摘要:
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.
摘要:
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).