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 invention relates to a method for transmitting signals termed useful signals via a satellite by means of connection stations. To this end, a first connection station (CNX1) carries out the generation of a first service signal on a service carrier frequency dubbed the pilot signal (Fp), and the transmission of this pilot signal to at least one second connection station (CNX2). The use of this pilot signal ensures phase synchronization and temporal synchronization of the signals so as to implement a transmit diversity, that is to say to toggle the transmission of the useful signal by this second connection station without loss of phase synchronization between the two stations. The invention applies to the Frequency Division Multiple Access (FDMA) signal communications by satellites.
摘要:
An interleaver (ER) is dedicated to interleaving of interleaving units representing a selected number of services grouped into periodic frames within a long period time interleaving radio communication network. The said interleaver (ER) comprises processing means (MT1) responsible for decomposing each frame into a chosen number of group(s) of service of constant respective durations, and then for distributing the interleaving units of each group into so-called spreading time intervals of constant respective durations spaced apart within a time interleaving period according to a period equal to the period of the frames.
摘要:
An onboard directional plane antenna comprises at least one array of radiating-slot waveguides comprising an alternating succession of three superposed metallic plates and of two dielectric substrates. The two substrates each comprise at least four adjacent waveguides, corresponding and communicating with one another pairwise by way of coupling slots. Each waveguide of the upper substrate furthermore comprises a plurality of radiating slots passing through the upper metallic plate, all the radiating slots of one and the same waveguide being parallel to one another and oriented in one and the same direction, the radiating slots of two adjacent waveguides being disposed in chevrons. Each waveguide of the lower substrate comprises an internal individual feed circuit comprising an individual electronic circuit for phase shifting and amplification.
摘要:
An onboard directional plane antenna comprises at least one array of radiating-slot waveguides comprising an alternating succession of three superposed metallic plates and of two dielectric substrates. The two substrates each comprise at least four adjacent waveguides, corresponding and communicating with one another pairwise by way of coupling slots. Each waveguide of the upper substrate furthermore comprises a plurality of radiating slots passing through the upper metallic plate, all the radiating slots of one and the same waveguide being parallel to one another and oriented in one and the same direction, the radiating slots of two adjacent waveguides being disposed in chevrons. Each waveguide of the lower substrate comprises an internal individual feed circuit comprising an individual electronic circuit for phase shifting and amplification.
摘要:
A satellite for a satellite telecommunication system transmits signals at different powers on the downlink connection. The powers are chosen to limit the relative dynamic range of signals received on the downlink connection. The relative dynamic range of signals received on the downlink connection is advantageously less than 5 dB and preferably less than 2 dB. A digital processor circuit is used, together with an analog-digital converter, a circuit taking the fast Fourier transform of the converted signals, a circuit for monitoring the gain of the signals, a circuit for switching the signals to at least two amplifier subsystems each including an inverse fast Fourier transform circuit, a digital-analog converter and a power amplifier.
摘要:
The invention relates to a method for transmitting signals termed useful signals via a satellite by means of connection stations. To this end, a first connection station (CNX1) carries out the generation of a first service signal on a service carrier frequency dubbed the pilot signal Fp, and the transmission of this pilot signal to at least one second connection station (CNX2). The use of this pilot signal ensures phase synchronization and temporal synchronization of the signals so as to implement a transmit diversity, that is to say to toggle the transmission of the useful signal by this second connection station without loss of phase synchronization between the two stations. The invention applies to the FDMA signal communications by satellites.
摘要:
A device (D) is dedicated to data stream processing within a communication satellite of a communication network. This device (D) comprises processing means (MT) whose job is, in the event of receipt of a first incoming data stream whose carrier exhibits a first modulation and comprising at chosen locations chosen insertion blocks, i) to detect the insertion blocks and at least one characteristic of the carrier of the first incoming stream, chosen from among its frequency, its phase, its timing and its amplitude, ii) to modulate, in accordance with the first modulation and having regard to each detected characteristic, data packets to be transmitted to a destination common with that of the first incoming stream, and iii) to replace with the modulated packets certain at least of the insertion blocks detected in the first incoming stream which has not been demodulated, so that the resulting stream is transmitted by the satellite, with its first original modulation, to the common destination so as to be demodulated therein as if it had been constituted by a single modulator.