• 专利附录
  • 专利说明
  • 权利要求
  • 类似技术
  • 同族专利
  • 引用文献
  • 法律状态
  • 优先权
    • 专利摘要:
    A method for calibrating a radio frequency multi-channel subsystem of a telecommunications payload comprises: a step of generating and injecting (304) a calibration signal at injection point (s) entrance access; a step of sampling the calibration signal injected and propagated at sampling points (306) of an access path at the exit; then - a step of estimating (308) amplitude and / or phase differences between the internal channels of the multichannel subsystem from the inputted calibration signal serving as a reference and the extracted calibration signal or signals; then .- a step of correction (310) of amplitude and / or phase differences by correction means. The injected calibration signal is a "CHIRP" type signal or chirps. A calibration system implements the calibration process.
    公开号:FR3077448A1
    申请号:FR1800105
    申请日:2018-02-01
    公开日:2019-08-02
    发明作者:Aline BRIAND；Eddy SOULEZ；Cecile Larue De Tournemine；Walid Karoui
    申请人:Centre National dEtudes Spatiales CNES；Thales SA；
    IPC主号:
    专利说明:

    Method and system for calibrating a radio frequency multichannel subsystem of a telecommunications payload
    The present invention relates to an on-board calibration method for a payload multi-channel radio frequency subsystem, in particular a flexible telecommunications payload, or any other payload carrying a subsystem requiring amplitude pairing. / phase of several radiofrequency channels between them.
    The technical field concerns the on-board calibration of radio frequency multi-channel subsystems used in flexible telecommunications payloads, and more particularly the calibration of semi-active or active Tx transmit or receive Rx antennas, declined according to DRA types (in English Direct Radiating Array ), AFSRA (in English Array Fed Shaped Reflector Antenna) and FAFR (in English Focal Array Fed Reflector), or sections of radiofrequency amplification of distributed power MPA (in English Multi-Port Amplifiers), formed by several power amplifiers, called ATOPs (in English TWTAs "Traveling Wave Tube Amplifiers) when they use traveling waves TOPs (in English" Traveling Wave Tubes "TWTs) and called SSPAs (in English" Solid State Power Amplifiers "SSPAs) solid state power components.
    The payloads use the antennas active in Tx transmission and / or in Rx reception for and use radiofrequency amplification sections of distributed power MPA to flexibly distribute several transmission channels to several output beams.
    Efforts are still being made to improve existing solutions for calibrating such radiofrequency multichannel subsystems, the calibration taking place while the satellite is in operation, at particular times during the lifetime of said multichannel subsystems where the performance of amplitude and phase difference between channels will have derived too much from a required requirement, for example due to changes in external temperature conditions applied to multi-channel subsystems or the aging of their internal components.
    The underlying problem of calibrating such multi-channel subsystems is to perform a precise calibration of the multi-channel subsystem while it transmits carriers of operational communications, that is to say to obtain the desired pairing in amplitude and in line with each other with sufficient precision, while ensuring the maintenance and integrity of the transmission quality of communications in progress.
    To this end and in a known manner, patent application US 2012/0280748 A1, forming a first document, describes a multi-port distributed amplification device, compensated in the presence of traffic.
    According to a first preferred embodiment, the multi-port distributed amplification device, compensated in the presence of traffic, is configured to inject an unmodulated reference signal and transmitted on a single carrier frequency. The value of this carrier frequency is chosen so that the reference signal is introduced between two communication channels without affecting its performance.
    According to a second embodiment and as a variant, the unmodulated reference signal transmitted on a single carrier of the first embodiment is replaced by a sinusoidal reference signal spread spectrally using a spreading code. In this case, the spread signal measurement device includes, in addition to the components used by the unmodulated signal measurement module, a module for despreading the signal received from the spread code used which is provided by a code generator. spreading.
    According to the multi-port distributed amplification device of the first document, the positioning of the reference signal to be injected into the guardbands between the traffic carriers, depends on the frequency plan of the traffic carriers coming from the planning of the mission of telecommunications, which lacks flexibility.
    In addition, the proposed waveforms of the calibration or reference signal to be injected as described in the first document for calibration, that is to say that of a simple non-modulated sinusoidal signal CW or that of a sinusoidal signal, spread spectrally using a spreading code, does not make it possible to inject the reference signal into a useful traffic carrier in all cases of configuration of the useful traffic carrier, for example a carrier of high order modulation more sensitive to noise or of high signal to noise ratio, or in cases where the duration of calibration must be limited. Indeed, the power of the required calibration signal, which must be low enough not to hinder the transmission of the useful carrier within which it is located, to comply for example with the performance criterion in Error Rate Package of 10 ~ 7 almost error free (Quasi Error Free) on the modulated useful carriers coded in DVB-S2), does not allow to estimate the amplitude and phase disparities between channels with sufficient precision.
    As is known, patent application US 2014/0354355 A1, forming a second document, describes a multi-port MPA distributed amplification device configured to maximize the isolation between its outputs by implementing a calibration process. .
    The calibration process uses the traffic signal itself to calibrate the MPA channels but does not use any dedicated calibration signal, having a suitable waveform and injected into at least one of the MPA channels.
    In the case where traffic carriers are used for frequency reuse in the MPA, the degradation of the signal-to-noise ratio of one of these carriers at MPA output, caused by aggregated insulation leaks from the other co-frequency carriers, can induce dispersive or even erroneous estimates of amplitude and inter-channel phase deviations, leading to incorrect calibration.
    Furthermore, each time the traffic signal is acquired on an output from the MPA, the corresponding traffic signal at the input of the MPA must be acquired simultaneously in order to be able to be compared or correlated to the traffic signal at the output. The solution described in the second document thus requires the use of a number of analog digital converters (ADC) twice that required in a conventional calibration system like that described in the first document.
    Thus, the calibration systems and methods described in the first and second documents have defects or drawbacks linked to operational constraints, in particular with regard to traffic frequency planning, or linked to performance limitations of estimation of errors between channels.
    A calibration method and system performing precise calibration of the multichannel subsystem while it transmits carriers of operational communications and avoiding the disadvantages of the systems of the first and second abovementioned documents are sought. The method and the system must make it possible to obtain the desired pairing in amplitude and in phase of the channels between them with sufficient precision, while ensuring the maintenance and integrity of the transmission quality of the communications in progress.
    The calibration of the multi-channel subsystem must be able to be carried out in narrow band, for example on 41 MHz in L band but also on a wide frequency band, for example on 2 GHz in Ku band or on 2.9 GHz in Ka band.
    The technical problem is to provide a method and a system for calibrating a multichannel RF subsystem of a telecommunications payload which allow precise calibration of the multichannel subsystem, at the same time as the transmission of the carriers. traffic, not penalizing for the frequency band used by the traffic carriers, and independent of the frequency position of the traffic carriers.
    To this end, the subject of the invention is a method for calibrating a radiofrequency multichannel subsystem of a telecommunications payload, the payload being included entirely in and on board a satellite or distributed on a satellite and a ground beam-forming station, the calibration taking place while the payload is in operation. The multi-channel subsystem comprises: a first integer N, greater than or equal to 2, of input access channels, and a second integer M, greater than or equal to 1, of output access channels, and a set of at least two internal channels, each formed by a chain of radio frequency components of the same architecture, either distributing the same input signal supplied by an input access channel over several output access channels, or concentrating several input signals respectively supplied by several input access channels on the same output access channel. The calibration process includes:
    .- a first step of generating and injecting a calibration signal at a predetermined injection point of an input access channel or at several predetermined points each associated with an input access channel different, then a second step of extracting the calibration signal injected and propagated in a predetermined sampling point of an exit access channel or in several predetermined sampling points each associated with a different output access channel, then .- a third step of estimating the amplitude and / or phase differences between the internal channels of the multi-channel subsystem from the calibration signal injected as an input and from the extracted calibration signal (s); then .- a fourth step of correcting amplitude and / or phase differences by one or more means for correcting said differences when one or more of these exceed a predetermined threshold.
    The calibration process is characterized in that the calibration signal injected is a “CHIRP” or chirp type signal.
    According to particular embodiments, the method for calibrating a radiofrequency multichannel subsystem comprises one or more of the following characteristics taken individually or in combination:
    .- the CHIRP type injected calibration signal is a complex signal s (t) of the form s (t) = a (t) .exp {/. φ (0] where a (t)> 0 is a low-pass amplitude whose time evolution is slow compared to the oscillations of the phase <p (t);
    .- the calibration signal injected is a signal of type linear “CHIRP” complex periodized s (t) of the form s (t) = Æexp {/. the instantaneous frequency: f (t) = - * d ( P (ÏÏ = Fl + F2 F1 evolving according to a periodic function of sawtooth type repeating according to a time period T1 a frequency ramp pattern varying linearly between a first value of frequency F1 and a second frequency value F2, the first F1 frequency value being equal to Fce - BWC * IRP and the second frequency value F2 being equal to Fce + BW p ~~ £ this designating a predetermined center frequency and. BW chirp designating the bandwidth of the CHIRP;
    .- the frequency positioning of the CHIRP type injected calibration signal is independent of the frequency plan of the traffic carriers;
    .- the spectrum of the CHIRP type injected calibration signal comprises a main lobe which has a bandwidth B chirp and which is included entirely in the band of a traffic carrier;
    the spectrum of the CHIRP type injected calibration signal comprises a main lobe which has a bandwidth B chirp and which is partially included in the band of a traffic carrier;
    .- the spectrum of the CHIRP type injected calibration signal comprises a main lobe which has a bandwidth B cflirp and which is included entirely in a guard band of the traffic carriers;
    the first step consists in generating and injecting calibration signals at a predetermined injection point of an input access channel or at several predetermined points each associated with a different input access channel, and the calibration signals injected are “CHIRP” or chirp type signals of the same bandwidth centered at different central frequencies distributed regularly over the communication band of the traffic carriers;
    .- during the third step the method of estimating the amplitude and / or phase differences between the internal channels of the multi-channel subsystem from the calibration signal injected as an input serving as a reference and the signal or signals taken as an output or a second type algorithm based on matching filtering by correlation;
    .- the calibration signal injected is a periodic linear complex type “CHIRP” signal s (t) of the form s (t) = Æexp; l at instantaneous frequency f (t), expressed by the equations:
    F2-Fl = Fl --—-- * t
    Tl d <p (t) 2π dt / (t) = evolving according to a periodic function of the sawtooth type repeating according to a time period ΊΊ a frequency ramp pattern varying linearly between a first frequency value F1 and a second value of frequency F2, the first frequency value F1 being equal to F ce ~ BWc * irp and the second frequency value F2 being equal to Fce + BWchirp tp this designating a predetermined center frequency and BW chirp designating the bandwidth of the CHIRP; and during the third step, the amplitude differences ΔΑ and / or of phase APhi between the internal channels of the multi-channel subsystem are estimated from the calibration signal injected at the input serving as a reference and the signal (s) taken as output, by extracting for each internal channel the calibration signal from the traffic signal by suitable filtering which maximizes the signal-to-noise ratio of the calibration signal and which maximizes a correlation function between the samples of the signal taken at the output and the samples of the calibration signal as a reference replica, and by estimating the amplitude A and the phase Phi of each internal channel from the maximum of correlation giving the complex gain and propagation delay of the calibration signal from its digital injection point to at the output of the adapted filtering; then by calculating the AA / APhi deviations of the internal channels relative to a predetermined reference channel from the estimated amplitude and phase A / Phi of each channel;
    when the telecommunications payload is fully included in and on board a satellite, the radio frequency multi-channel system is an MPA comprising two Butler matrices, with the Butler matrix of digital or analog input, without training network. BFN beams, integrated in an active or not antenna; or an MPA with a BFN beam forming network at digital or analog input and a Butler matrix at output, integrated within an active or not antenna; or an MPPA parallel multiport amplifier comprising amplifiers paralleled inside an MPA, integrated within an active or not antenna; or a semi-active antenna called "Multimatrix" with reflector, with or without MPA; or an active antenna of the DRA direct radiation network type or a sub-reflector antenna supplied by an AFSRA source network or a reflector antenna supplied at its focal point by a FAFR source network with an analog or digital BFN; or an on-board function requiring the amplitude / phase pairing of several channels between them; and when the telecommunication payload is distributed over a satellite and a ground beam-forming station, the radio frequency multi-channel system is an active satellite antenna in Rx reception mode with effective beam formation on the ground GBBF; or an active satellite antenna in Tx transmission mode with effective formation of beams on the ground GBBF, with or without an MPA or MPPA function entirely on board or with or without an MPA or MPPA function whose input Butler matrix is distributed on the ground ;
    .- the fourth step is carried out directly on board the satellite or on the ground.
    A subject of the invention is also a system for calibrating a radio frequency multi-channel subsystem of a telecommunications payload, the payload being included entirely in and on board a satellite or distributed on a satellite and a ground beam-forming station, the calibration taking place while the payload is in operation.
    The multi-channel subsystem comprises a first integer N, greater than or equal to 2, of input access channels, and a second integer M, greater than or equal to 2, of output access channels, and a set at least two internal channels, each formed of a chain of radiofrequency components of the same architecture, either distributing the same input signal supplied by an input access channel over several output access channels, or concentrating several input signals respectively supplied by several input access channels on the same output access channel.
    The calibration system comprises a first device for injecting an analog or digital calibration signal at a predetermined injection point of an input access channel or at several predetermined points each associated with an access channel different entry; and a second device for sampling the calibration signal injected and propagated in a predetermined sampling point of an output access channel or in several predetermined sampling points each associated with a different output access channel; and a third digital computing device, formed by one or more electronic computers, and configured to: generate a digital calibration signal corresponding to the digital or analog version of the calibration signal injected by the first device; and extract the calibration signal injected from the signal or signals sampled at the predetermined sampling point of an output access channel or at the predetermined sampling points each associated with a different output access channel and from the signal generated calibration; estimate amplitude and / or phase differences between the internal channels of the multi-channel subsystem from the calibration signal injected as a reference and from the extracted calibration signal (s); and correct amplitude and / or phase deviations by controlling one or more means for correcting said deviations when one or more of said deviations exceed a predetermined threshold. The calibration system being characterized in that the calibration signal injected is a “CHIRP” or chirp type signal.
    According to particular embodiments, the system for calibrating a multi-channel subsystem comprises one or more of the following characteristics taken individually or in combination:
    .- the calibration signal injected is a signal of type linear CHIRP complex periodized s (t) of the form s (t) = Æexp the instantaneous frequency f (t), defined by the equations:
    fm = ± .i £ m = F1 + £ ^. tt evolving according to a sawtooth type periodic function repeating, over a time period T1, a frequency ramp pattern varying linearly between a first frequency value F1 and a second frequency value F2, the first frequency value F1 being equal to F ce - BWc * lrp and the second frequency value F2 being equal to Pce + BWc * irp t F ce designating a predetermined center frequency and BW chirp designating the bandwidth of CHIRP; and the frequency positioning of the CHIRP type injected calibration signal is independent of the frequency plan of the traffic carriers;
    .- the first and second devices are configured to generate and inject calibration signals at a predetermined injection point of an input access channel or at several predetermined points each associated with an input access channel different, and the calibration signals injected are “CHIRP” or chirp signals of the same bandwidth centered at different central frequencies regularly distributed over the communication band of the traffic carriers;
    .- when the telecommunications payload is fully included in and on board a satellite, the radio frequency multi-channel system is an MPA comprising two Butler matrices, with the digital or analog input Butler matrix, without a formation of BFN beams, integrated within an active antenna or not; or an MPA with a BFN beam forming network at digital or analog input and a Butler matrix at output, integrated within an active or not antenna; or an MPPA parallel multiport amplifier comprising amplifiers paralleled inside an MPA, integrated within an active or not antenna; or a semi-active antenna called "Multimatrix" with reflector, with or without MPA; or an active antenna of the DRA direct radiation network type or a sub-reflector antenna supplied by an AFSRA source network or a reflector antenna supplied at its focal point by a FAFR source network with an analog or digital BFN; or an on-board function requiring the amplitude / phase pairing of several channels between them; and when the telecommunication payload is distributed over a satellite and a ground beam-forming station, the radiofrequency multichannel system is an active satellite antenna in Rx reception mode with effective beam-forming on the ground GBBF, or an active satellite antenna in mode Tx emission with effective beam formation on the ground GBBF, with or without an MPA or MPPA function entirely on board or with or without an MPA or MPPA function whose input Butler matrix is distributed on the ground.
    The invention will be better understood on reading the description of several embodiments which will follow, given solely by way of example and made with reference to the drawings in which:
    .- Figure 1 is a view of a first example of a multi-channel subsystem, a so-called passive MPA with reference to the passive Butler matrices used therein, which is part of an on-board telecommunications payload a satellite and can advantageously be calibrated by a system and a method of calibration according to the invention;
    .- Figure 2 is a view of a second example of a multi-channel subsystem, a so-called active MPA with reference to an analog or digital active matrix (or BFN) making it possible to load laws of amplitude and phase on each channel of each beam, which is part of a telecommunications payload on board a satellite and can advantageously be calibrated by a system and a method of calibration according to the invention;
    .- Figure 3 is a view of a third example of a radio frequency multi-channel subsystem, an active antenna with sub-reflector supplied by an AFSRA source network in Tx transmission mode which is part of an on-board telecommunications payload at on board a satellite and can advantageously be calibrated by a system and a calibration method according to the invention;
    Figure 4 is a view of a fourth example of a radio frequency multi-channel subsystem, an active forward path antenna which is part of a multi-beam telecommunications payload distributed over a satellite and a ground beam-forming station and may advantageously be calibrated by a calibration system and method according to the invention;
    .- Figure 5 is a view of a fifth example of a radio frequency multi-channel subsystem, an active return path antenna which is part of a multi-beam telecommunications payload distributed over a satellite and a ground beam-forming station and can advantageously be calibrated by a calibration system and method according to the invention;
    .- Figure 6 is a general view of a calibration system according to the invention of a radio frequency multi-channel subsystem of a telecommunications payload such as those of Figures 1 to 5;
    .- Figure 7 is a flowchart of a calibration method according to the invention of a radio frequency multi-channel subsystem of a telecommunications payload such as those of Figures 1 to 5 .- Figure 8 is a view general of the temporal evolution of the frequency of an injected calibration signal corresponding to a preferred embodiment of the invention;
    .- Figure 9 is a view of an example of temporal evolution of the real part of the amplitude of a pattern of an injected calibration signal corresponding to an example of the preferred embodiment of the following injected calibration signal the invention described in Figure 8;
    FIG. 10 is a view of an example of a spectrum typical of a calibration signal having the frequency evolution form described in FIG. 8;
    .- Figure 11 is a view of an example of the spectrum used by traffic carriers of a telecommunications payload in which the spectrum of the calibration signal is completely embedded in the spectrum of a carrier with a power d interference sufficiently negligible so as not to disturb the traffic on this carrier while allowing calibration and an accurate estimation of the amplitude / phase disparities predicted;
    FIG. 12 is a view of another example of the spectrum used by traffic signals passing over a channel i for transmission of the telecommunications payload and of the spectrum used by the calibration signal when it is injected sequentially along the useful band of the transmission channel i;
    FIG. 13 is a detailed flowchart of an embodiment of the step of extracting the calibration signal from the calibration method according to the invention of FIG. 7;
    .- Figure 14 is a comparative view of the correlation function maximized by suitable filtering of a reference CHIRP calibration signal and of an extracted CHIRP calibration signal using the waveform whose examples of characteristics are described in Figures 8 to 10.
    The basic concept of the invention resides in the use of a calibration signal dedicated to the calibration function and in the conventional implementation of the following four steps consisting in:
    .- inject a calibration signal at one or more precise injection points of a radiofrequency multichannel subsystem of a telecommunications payload, and .- extract this calibration signal at one or more sampling and output points of said subsystem to be calibrated, and .- estimate amplitude and / or phase differences between the internal channels of the subsystem, and .- possibly correct amplitude and / or phase differences with suitable electronic means , for example means having the function of a digital phase shifter and implemented in one of the items of equipment of the multi-channel subsystem. These corrections can alternatively be defined on the ground from the estimates of the amplitude / phase deviations calculated on board and transmitted to the ground, then applied on board.
    The basic concept of the invention resides in the capacity of the calibration system to calibrate a multi-channel subsystem with a calibration signal which can be "drowned" in a traffic carrier, which can have a positioning independent of the frequency plan of traffic carriers, and which makes it possible to obtain at the same time the quality required for the calibration performance and the non-degradation of the transmission quality of a traffic carrier possibly interfered with by the calibration signal.
    The basic concept of the invention is based on the particular nature of the waveform of the calibration signal used which is that of a CHIRP or "chirp" type signal, associated with a specific processing of this CHIRP signal. Thus, the calibration signal can be placed anywhere in the frequency band allocated to the telecommunications service of the payload, in particular in a traffic carrier which in this case interferes with the calibration signal.
    The calibration system and method according to the invention are configured to calibrate a large family of radio frequency multichannel subsystems, each part of a telecommunications payload.
    The function of the multi-channel subsystem can be fully included in and carried on board the payload of a satellite or can be distributed on a satellite and a ground beam-forming station, the calibration taking place while the payload is in operation.
    In general, a multi-channel subsystem calibrated by a calibration system according to the invention comprises:
    a first integer N, greater than or equal to 2, of input access channels, and .- a second integer M, greater than or equal to 2, of output access channels, and .- a set of at least two internal channels, each formed by a chain of radio frequency components of the same architecture, either distributing the same input signal supplied by an input access channel over several output access channels, or concentrating several signals 'input provided respectively by several input access channels on the same output access channel.
    When the function of the multi-channel subsystem is fully included in and on board the payload of a satellite, the radio-frequency multi-channel system is:
    .-one MPA comprising two Butler matrices with the Butler matrix of digital or analog input without BFN beamforming network, integrated within an active or not antenna; or an MPA with a Beam Forming Network (BFN) in digital or analog input and a Butler matrix at output, integrated within an active or not antenna; or .- a multi-port parallel amplifier MPPA (in English Multi Port Parallelized Amplifier) comprising amplifiers paralleled inside a MPA, integrated within an active or not antenna; or .- an active antenna of the DRA direct radiation network type or a sub-reflector antenna supplied by an AFSRA source network or a reflector antenna supplied at its focal point by a FAFR source network with an analog or digital BFN; or .- a semi-active antenna called "Multimatrix" with reflector, with or without MPA; or .- any other function on board a satellite for telecommunications, observation, navigation, etc., which would require the amplitude / phase pairing of several channels between them, even not mentioned in this document.
    According to Figure 1 and a first example of a multi-channel subsystem, a passive MPA 12, forming part of a telecommunications payload on board a satellite, comprises two Butler matrices 14, 16 without a beam-forming network BFN, a set 22 of N input access channels, a set 24 of M output access channels and a set 26 of at least two internal channels, formed here by amplification chains. When the Butler matrices have the same number of inputs as outputs, M is equal to N.
    According to FIG. 2 and a second example of a multi-channel subsystem, an active MPA 32, forming part of a telecommunications payload on board a satellite, comprises as input a digital beam forming network BFN 34 or analog, a Butler matrix 36 at output, a set 42 of N input access channels, a set 44 of M output access channels and a set 46 of at least two internal channels, formed here by chains amplification.
    According to FIG. 3 and a third example of a radiofrequency multi-channel subsystem, an active antenna 52 with a sub-reflector supplied by an AFSRA source network and in Tx transmission mode, forming part of a telecommunications payload on board a satellite, includes a BFN network 54 for forming Tx beams, digital or analog, a set 62 of N input access channels, a set 64 of M output access channels and a set 66 of at least two internal channels, formed here by RF power amplification chains.
    When the function of the multi-channel subsystem is distributed over the telecommunications payload is on board a satellite and on a beam-forming ground station, the radio-frequency multi-channel system is:
    .- an active satellite antenna in Rx reception mode with effective formation of beams on the ground GBBF (in English Ground Based Beam Forming); or .- an active satellite antenna in Tx transmission mode with effective formation of beams on the ground GBBF with or without an MPA or MPPA function entirely on board or with or without an MPA or MPPA function whose input Butler matrix is distributed as well ground.
    According to FIG. 4 and a fourth example of a radiofrequency multichannel subsystem, an active antenna 72 in forward channel Tx transmission mode forms part of a multibeam telecommunications payload by being distributed over a satellite and a ground beam-forming station. GBBF, and includes:
    .- at ground level a module 74 for forming GBBF beams, a multiplexer 76 for concentrating the output channels of the module 74 GBBF, and a transmitter-antenna unit RF transmission Tx 80, configured to transmit the multiplex stream to the satellite on a link RF 78 broadband;
    .- at satellite level an RF antenna-receiver assembly 84 for receiving the multiplex stream RF, a demultiplexer 86 for demultiplexing the multiplex stream into source channels intended to supply the multibeam Tx antenna;
    .- at ground level, a set 92 of N access channels at the input of beams from the active multibeam Tx antenna, and at satellite level, a set 94 of M output access channels connected to the sources of the antenna Multibeam Tx;
    .- a set 96 of at least two internal channels, formed here by the 74 GBBF module, the multiplexer 76, the RF transmitter-antenna assembly Tx transmission 80, the uplink RF link 78 high speed single-beam, the assembly RF receiver antenna 84 for receiving the multiplex stream RF, the demultiplexer 86, and possibly a set of M associated transposition / amplification chains each connected upstream of a different output access.
    As a variant, the multi-channel subsystem to be calibrated may be the portion of the active antenna 72 in transmission mode, comprised between the output of the 74 GBBF module and the input 94 of the sources of the Tx antenna.
    According to FIG. 5 and a fifth example of a radio frequency multi-channel subsystem, an active multibeam antenna 102 in return channel Rx reception mode is part of a multibeam telecommunications payload distributed by being distributed over a satellite and a ground training station. of GBBF beams, and includes:
    .- at satellite level, a set 103 of N amplification and / or transposition chains each connected to a different source from the active multibeam Rx antenna, a multiplexer 104 of the source channels, possibly transposed, into a composite multiplex signal, and a single beam Tx 108 transmitter-antenna assembly, configured to transmit the stream to the ground station on a downlink RF high-speed link 106;
    .- at ground level, an RF antenna-receiver assembly 112 for receiving the multiplex stream, a demultiplexer 114 for demultiplexing the multiplex stream into source channels, and a 116 GBBF beam forming module for the Rx beams;
    .- at the satellite level, a set 122 of N access channels at the input sources of the active multi-beam Rx antenna, and at the ground level, a set 124 of M access channels at the return channel Rx beams output;
    .- a set 126 of at least two internal channels, formed here by the set 103 of N amplification and / or transposition chains, the multiplexer 104 of the source channels, the transmitter-antenna RF satellite transmission Tx 108, the downlink RF high-speed single-beam 106, the RF antenna-receiver unit 112 ground for receiving RF of the multiplex flow of the source channels, the demultiplexer 114, and the beam forming module 116 GBBF of the Rx beams.
    As a variant, the multi-channel subsystem to be calibrated can be the portion of the active antenna 102 in reception mode, comprised between the output 122 of the sources of the antenna Rx and the input of the beam forming module 116GBBF.
    According to Figure 6 and in general, a calibration system 202 of a radio frequency multi-channel subsystem 204 of a telecommunications payload, such as for example those described in Figures 1 to 5, having a first set 206 of N input access channels and a second set 208 of M output access channels, includes:
    a first device 212 for injecting an analog or digital calibration signal at a predetermined injection point of an input access channel or at several predetermined injection points each associated with an access channel d 'different entry; and a second device 214 for sampling the propagated composite signal, formed by the calibration signal and the traffic signal, at a predetermined sampling point of an exit access route or in several predetermined sampling points each associated with a different exit route; and .- a third device 216 for generating the digital calibration and calculation signal, formed by one or more electronic computers.
    According to Figure 6 and as a specific example, each input access channel includes an injection point, produced here by a coupler or a digital adder, the injection points of the three input access channels illustrated in Figure 6 being designated by the reference numerals 222, 224, 226. Similarly, each output access channel includes a point for sampling the composite signal for calibration and traffic, produced for example by a coupler or by a device digital acquisition, the sampling points of the three output access channels illustrated here in Figure 6 being designated by the reference numerals 232, 234, 236.
    The third device for generating the digital calibration and calculation signal 216 is configured to:
    .- generating a digital calibration signal corresponding to the digital or analog version of the calibration signal injected by the first device 212; and .- extracting the calibration signal from the multiplex (s) of traffic signals and of calibration signal sampled at the predetermined sampling point of an exit access channel or at the predetermined sampling points each associated with a different output access path and the generated calibration signal;
    estimate amplitude and / or phase differences between the internal channels of the multi-channel subsystem from the calibration signal injected as a reference and from the extracted calibration signal (s); and .- define corrections to minimize amplitude and / or phase deviations, then apply them by ordering one or more means for correcting said deviations when one or more of said deviations exceed a predetermined threshold;
    According to FIG. 7, a method 302 for calibrating a radio frequency multi-channel subsystem of a telecommunications payload comprises a set of steps.
    In a first generation and injection step 304, a calibration signal is generated and injected at a predetermined injection point of an input access channel or at several predetermined points each associated with an access channel different entry.
    Then in a second extraction step 306, the calibration signal injected and propagated in a predetermined sampling point of an exit access channel or in several predetermined sampling points each associated with a different output access channel , is extracted.
    Then in a third estimation step 308, amplitude and / or phase differences between the internal channels of the multi-channel subsystem are estimated from the calibration signal injected as an input and from the calibration signal (s) extracts.
    Then, in a fourth correction step 310, amplitude and / or phase deviations are corrected by one or more means for correcting said deviations when one or more of these exceed a predetermined threshold.
    The system 202 and the calibration method 302 are characterized in that the calibration signal injected is a “CHIRP” or chirp type signal.
    In general, the CHIRP type injected calibration signal is a complex signal s (t) of the form s (t) = a (t) -exp {/.<p(t)} where a (t)> 0 is a low-pass amplitude whose time evolution is slow compared to the oscillations of the phase <p (t).
    It should be noted that the fourth step 310 can be carried out directly on board the satellite or on the ground.
    According to a first embodiment, the first step 304 consists in generating and injecting one or more calibration signals at a predetermined injection point of an input access channel or at several predetermined points each associated with a d 'different input access, the calibration signals injected being signals of the “CHIRP” or chirping type with the same bandwidth centered at the same central frequency.
    According to a second embodiment, the first step 304 consists in generating and injecting calibration signals at a predetermined injection point of an input access channel or at several predetermined points each associated with an access channel of different input, the injected calibration signals being “CHIRP” or chirping signals of the same bandwidth centered at different central frequencies distributed regularly over the communication band of the traffic carriers.
    During the third step 308, the method for estimating the amplitude and / or phase differences between the internal channels of the multi-channel subsystem from the calibration signal injected at the input serving as a reference and the signal or signals taken as output uses a second type algorithm based on matching filtering by correlation.
    According to FIG. 8 and preferably, the calibration signal injected is a signal of type linear “CHIRP” complex periodized s (t) of the form s (t) = A.exp [j. (P (t)}, the instantaneous frequency f (t), defined by the equations: / (t) = - * = Fl + F2 ~ F1 * t, evolving according to a function 1 v '2π dt Periodic sawtooth type 354 repeating according to a period temporal Chirp a frequency ramp pattern 356 varying linearly between a first frequency value F1 and a second frequency value F2.
    The first frequency value F1 is equal to F ce - BWc * irp and the second frequency value F2 is equal to F ce _l ^ irp, designating a predetermined center frequency and BW chirp designating the bandwidth of CHIRP.
    For each point of sampling of the calibration signal, the sampling and processing of the calibration signal concerns a sequence of a predetermined number Nacq of consecutive patterns each having a frequency ramp shape. The Tacq acquisition period of the calibration signal is thus equal to Nacq * Tchirp.
    According to FIG. 9, a temporal evolution 372 of the real amplitude 374 of s (t) of a pattern of a calibration signal injected before processing corresponds to a typical example of the preferred embodiment of the calibration signal injected according to l invention described in Figure 8;
    According to Figure 10, an example of spectrum 392 of a CHIRP signal having the frequency evolution form described in Figure 8 and a bandwidth Bchirp equal to 500 kHz is illustrated at a central frequency after transposition Fce equal to 3.5 MHz . The spectrum 392 describes the variation 394 of the signal power spectral density, expressed in dBW / band resolution of the spectrum analyzer, as a function of the frequency expressed in MHz.
    Consequently, thanks to the particular CHIRP waveform used by the calibration signal, the frequency positioning of the injected calibration signal of the CHIRP type can be independent of the frequency plan of the traffic carriers without this affecting performance. calibration in terms of precision of the estimated deviations of the inter-channel amplitude / phase between internal channels nor does it degrade the communications performance of the traffic carriers.
    According to FIG. 11 and a first particular configuration of the frequency plan 402 of the traffic carriers, almost all of the power of the calibration signal 394 is concentrated in the main lobe 404 of said calibration signal injected of the CHIRP type, the main lobe having a bandwidth BW chirp , being included entirely in the band of a traffic carrier 412 and interfering with this traffic carrier 412 with a relative power level which can be very low, for example less than or equal to -30 dB / BWchirp or -30dB + 10log (BWchirp / Rs) in the Rs band of the symbol symbol of the traffic carrier. After extraction, the signal to noise ratio of the calibration signal reaches a sufficiently high level, for example 26dB, making it possible to guarantee good calibration performance, that is to say to make precise estimates of the amplitude / phase differences between channels. , for example to obtain dispersions of deviations of the order of 0.5 degrees in sigma phase and 0.04dB in sigma amplitude without degrading the communication performance of the traffic carrier.
    As a variant and according to a second particular configuration of the frequency plan of the traffic carriers, the spectrum of the calibration signal injected of the CHIRP type comprises a main lobe which has a bandwidth Bchirp and which is partially included in the band of a carrier traffic with a suitable relative power level to guarantee good calibration performance without degrading the communication performance of the traffic carrier.
    As a variant and according to a third particular configuration of the frequency plan of the traffic carriers, the spectrum of the calibration signal injected of the CHIRP type comprises a main lobe which has a bandwidth Bchirp and which is included entirely in a guard band of the carrying traffic.
    According to FIG. 12 and an example of the frequency plan 422 of a transmission channel i, the transported traffic 424 is represented by contours in dotted lines and comprises a set of loaded carriers 426, 428, 430, 432, 434, 436 of different spectral occupations. In the useful band of the transmission channel i, the calibration signal 438, represented by solid line contours, is here injected sequentially at different times along the spectral band of the channel at corresponding frequency intervals spaced regularly. Unplanned vis-à-vis the traffic frequency plan, the injected calibration signal can fall inside or on horseback or outside a loaded carrier.
    According to FIG. 13 and the preferred mode of the invention described in FIG. 8, the third step 308 in which the differences in amplitude ΔΑ and / or in phase APhi between the internal channels of the multi-channel subsystem are estimated from the calibration signal injected at the input serving as a reference and the signal or signals taken at the output, comprises first, second and third sub-steps 452, 454, 456.
    In the first sub-step 452, for each internal channel the calibration signal of the traffic signal is extracted by a suitable filtering which maximizes the signal to noise ratio of the calibration signal and which maximizes a correlation function between the samples of the sampled signal at output and the samples of the calibration signal as reference replica.
    Then, in the second sub-step 454, the amplitude A and the phase Phi of each internal channel are estimated from the maximum of correlation giving the complex gain and propagation delay of the calibration signal from its digital injection point to at the output of the adapted filtering.
    Then, in the third sub-step 456, the deviations ΔΑ / APhi of the internal channels relative to a predetermined reference channel are calculated from the estimated amplitudes and phase A / Phi of each internal channel.
    According to FIG. 14, a measured calibration signal, illustrated by a first curve 482, is extracted from the traffic signal in the first substep 452 of the third step 308 by a suitable filtering technique, making it possible to maximize the signal to noise ratio of the complex correlated signal C (t) between the samples of the sampled output signal Sp (t) and the samples of the input calibration signal E (t), C (t) being expressed by the following equation:
    C (t) = Sp (t) ®E * (- t)
    A second curve 484 illustrates the maximized correlation in signal to noise ratio of the complex correlated signal of the reference calibration signal serving as a replica with itself.
    A third curve 486 illustrates the noise extracted by the adapted filtering.
    The extraction of the calibration signal taken by a suitable filtering allows an injection of a calibration signal at very low level, for example -30dB relative to the power of the traffic signal interfering with the band of the calibration signal, and to extract the CHIRP signal embedded in the loaded traffic carrier, with maximum processing gain, to obtain an objective positive signal-to-noise ratio of the calibration signal, guaranteeing the accuracy of error estimation.
    This objective signal-to-noise ratio of the calibration signal depends on the injection level relative to that of the traffic carrier in the band of the calibration signal, on the characteristics of the CHIRP signal (band and duration), on the number of Nacq acquisitions for each channel allowing a time averaging.
    At the same time, the level of injection of the calibration signal being very low, the transmission of the telecommunication signal on the traffic carrier is integrated with a degradation of bit BER error rate and of its signal to noise ratio C / N in the carrier band useful in the measurement accuracy of measuring devices.
    It should be noted that the injection of a calibration signal at an injection point can be implemented on an access channel at the input of the payload, in digital via one or more digital / analog converters DAC ( in English Digital to Analogue Converter DAC) of a transparent digital processor DTP (in English Digital Transparent Processor) or non-transparent, in analog by coaxial coupler for example.
    It should be noted that the signal sampled at a point of sampling and extraction of the injected and propagated propagation signal is actually a composite signal including part or all of a loaded traffic carrier and all of the calibration signal. , and that the sampling of the digital signal can be implemented on the access channel at the output of the payload, in digital after the demultiplexer function of a digital processor transparent or not, or in analog by coaxial coupler for example, then digitized by an acquisition chain which can be a processor chain or an additional chain.
    It should be noted that in cases where calibration is necessary over a wide frequency band, for example 2 GHz in Ku band, the steps of injecting the calibration signal, extracting the calibration signal, estimating errors between channels are produced sequentially, by placing the calibration signal sequentially at several frequency positions in the frequency band or frequency sub-bands of the frequency plane of the traffic carriers.
    The calibration method and system according to the invention, described above, allow for a multi-channel subsystem of an on-board telecommunications payload, to carry out a calibration on board the satellite to guarantee the performance of said multi-channel subsystem on the lifetime of the satellite, in operational conditions without interrupting telecommunications traffic, and without operational constraints in terms of frequency of the traffic carriers.
    Little additional material is to be inserted on board the satellite, the list of this material comprising: coaxial couplers if not provided in the payload, an array of RF switches in Tx transmission mode, an RF divider in Rx reception mode, a chain frequency conversion by transposition (one for RF / FI conversion in Tx transmission mode and one for FI / RF in Rx reception mode) and an RF harness. The digital processing of the signals, the estimation of the errors and the definition of the corrections can be implemented on board the satellite in an already existing equipment for the payload according to the architecture of the latter or an equipment dedicated to the only calibration function.
    The on-board payload multi-channel subsystem can be an active or semi-active antenna.
    The multi-channel subsystem of the on-board payload can be a multi-port MPA amplification device by which carriers in frequency reuse are transmitted, due to the fact that it is the signal to noise ratio of the calibration signal, and not not the signal-to-noise ratio of a traffic carrier, which will drive the correct estimation of the amplitude and phase errors. Indeed, on an output port of the MPA where a traffic carrier and the interfered calibration signal recombine, the aggregated isolation leaks of the other co-frequency traffic carriers will be second order compared to the power of the carrier interfering with the calibration signal. In this case, the calibration system requires only an analog-digital ADC converter to digitize the composite signal by sampling point at the output of the multi-channel subsystem, since the reference digital calibration signal is generated on board and only there is no need to acquire it in parallel with the acquisition of the output sampling signal.
    Alternatively, the method and the calibration system according to the invention, described above, allow for a multichannel subsystem of a telecommunications payload, forming an active antenna in Tx transmission mode or in Rx reception mode with training. of GBBF ground beams, and distributed on a satellite and a ground station, to carry out a distributed calibration on the satellite and the ground station to guarantee the performance of said multi-channel subsystem over the lifetime of the satellite, in operational conditions without interrupting telecommunications traffic, and without operational constraints in terms of frequency of traffic carriers.
    It should be noted that the calibration method and the calibration system can be limited in their use to a simple monitoring of the multi-channel subsystem, without application of corrections.
    It should be noted that the calibration process and the calibration system can also be used to align the channels of multi-channel subsystems in the assembly, integration and AIT test phase (in English Assembly, Integration and Test) .
    权利要求:
    Claims (16)
    [1" id="c-fr-0001]
    1. Method for calibrating a radiofrequency multichannel subsystem (12; 32; 52; 72; 102; 204) of a telecommunications payload, the payload being fully included in and on board a satellite or distributed over a satellite and a ground beam-forming station, the calibration taking place while the payload is in operation, the multi-channel subsystem (12; 32; 52; 72; 102; 204) comprising:
    .- a first integer N, greater than or equal to 2, of input access channels, and .- a second integer M, greater than or equal to 1, of output access channels, and .- a set (26; 46; 66; 96; 126) of at least two internal channels, each formed of a chain of radiofrequency components of the same architecture, or distributing the same input signal supplied by an input access channel on several output access channels, ie concentrating several input signals respectively supplied by several input access channels on the same output access channel, the calibration method comprising:
    .- a first step (304) of generating and injecting a calibration signal at a predetermined injection point of an input access channel or at several predetermined points each associated with an access channel different input, then .- a second step (306) of extracting the calibration signal injected and propagated at a predetermined sampling point of an exit access channel or in several predetermined sampling points each associated with a different output access channel, then .- a third step (308) of estimating the amplitude and / or phase differences between the internal channels of the multi-channel subsystem from the calibration signal injected as input reference and extracted calibration signal (s); then .- a fourth step (310) of correction of the amplitude and / or phase deviations by one or more means for correcting said deviations when one or more of these exceed a predetermined threshold;
    the calibration process being characterized in that:
    the calibration signal injected is a “CHIRP” or chirp type signal.
    [2" id="c-fr-0002]
    2. Method for calibrating a radiofrequency multichannel subsystem according to claim 1, in which the injected calibration signal of CHIRP type is a complex signal s (t) of the form s (t) = a (t) .exp {/.<p(t)} where a (t)> 0 is a low-pass amplitude whose time evolution is slow compared to the oscillations of the phase <p (t).
    [3" id="c-fr-0003]
    3. Method for calibrating a radiofrequency multi-channel subsystem according to claim 1, in which the calibration signal injected is a signal of linear complex periodic “CHIRP” type s (t) of the form s (t) = A.exp the instantaneous frequency: f (t) = - * = Fl -I- 7 v 7 2π dt Tl evolving according to a periodic function of sawtooth type repeating according to a time period T1 a ramp pattern of frequency varying linearly between a first frequency value F1 and a second frequency value F2,
    The first frequency value F1 being equal to F ce - —Vr p and the second frequency value F2 being equal to Fce + BWc * irp tp ce designating a predetermined center frequency and BW chirp designating the bandwidth of CHIRP.
    [4" id="c-fr-0004]
    4. Method for calibrating a radiofrequency multichannel subsystem according to any one of claims 1 to 3 in which the frequency positioning of the injected calibration signal of the CHIRP type is independent of the frequency plane (402) of the traffic carriers.
    [5" id="c-fr-0005]
    5. Method for calibrating a radiofrequency multichannel subsystem according to any one of claims 1 to 4, in which the spectrum of the CHIRP type injected calibration signal comprises a main lobe which has a bandwidth B cflirp and which is fully included in the band of a traffic carrier.
    [6" id="c-fr-0006]
    6. Method for calibrating a radiofrequency multichannel subsystem according to any one of claims 1 to 4, in which the spectrum of the CHIRP type injected calibration signal comprises a main lobe which has a bandwidth B chirp and which is partially included in the band of a traffic carrier.
    [7" id="c-fr-0007]
    7. Method for calibrating a radiofrequency multichannel subsystem according to one of claims 1 to 4, in which the spectrum of the CHIRP type injected calibration signal comprises a main lobe which has a bandwidth B chirp and which is fully included in a traffic carrier guard band.
    [8" id="c-fr-0008]
    8. Method for calibrating a radiofrequency multichannel subsystem according to any one of claims 1 to 7, in which the first step (304) consists in generating and injecting calibration signals at a predetermined injection point of an input access channel or at several predetermined points each associated with a different input access channel, and the calibration signals injected are “CHIRP” or chirp signals of the same bandwidth centered at different central frequencies regularly distributed over the communication band of the traffic carriers.
    [9" id="c-fr-0009]
    9. Method for calibrating a radiofrequency multichannel subsystem according to any one of claims 1 to 8, in which during the third step (308) the method for estimating amplitude and / or phase deviations between the internal channels of the multi-channel subsystem from the calibration signal injected at the input serving as a reference and the signal (s) sampled at the output or a second type algorithm based on filtering adapted by correlation.
    [10" id="c-fr-0010]
    10. A method of calibrating a radiofrequency multichannel subsystem according to any one of claims 1 to 9, in which the calibration signal injected is a signal of linear complex periodic “CHIRP” type s (t) of the form s (t) = A. exp [j. <p (t)} the instantaneous frequency f (t), expressed by the equations:
    1 d <p (t) 2π dt
    F2-F1 = Fl + ——— * t Tl evolving according to a periodic function of sawtooth type repeating according to a time period T1 a frequency ramp pattern varying linearly between a first frequency value F1 and a second frequency value F2 ,
    The first frequency value F1 being equal to F ce - BWc * ir v e t the second frequency value F2 being equal to F ce +, F ce denoting a predetermined center frequency and BW chirp denoting the bandwidth of the CHIRP; and during the third step (308), the amplitude deviations ΔΛ and / or of phase APhi between the internal channels of the multi-channel subsystem are estimated from the calibration signal injected as a reference and the one or more signals sampled at the output, by extracting (452) for each internal channel the calibration signal from the traffic signal by suitable filtering which maximizes the signal-to-noise ratio of the calibration signal and which maximizes a correlation function between the samples of the sampled signal at output and the samples of the calibration signal as reference replica, and by estimating (454) the amplitude A and the phase Phi of each internal channel from the maximum of correlation giving the complex gain and propagation delay of the calibration signal from its digital injection point to the exit of the adapted filtering; then by calculating (456) the AAI APhi deviations of the internal channels relative to a predetermined reference channel from the estimated amplitude and phase A / Phi of each channel.
    [11" id="c-fr-0011]
    11. Method for calibrating a radiofrequency multichannel subsystem according to any one of claims 1 to 9, in which when the telecommunications payload is fully included in and on board a satellite, the radiofrequency multichannel system is an MPA comprising two Butler matrices, with the Butler matrix of digital or analog input, without BFN beamforming network, integrated into an active antenna or not; or an MPA with a BFN beam forming network at digital or analog input and a Butler matrix at output, integrated within an active or not antenna; or an MPPA parallel multiport amplifier comprising amplifiers paralleled inside an MPA, integrated within an active or not antenna; or a semi-active antenna called "Multimatrix" with reflector, with or without MPA; or an active antenna of the DRA direct radiation network type or a sub-reflector antenna supplied by an AFSRA source network or a reflector antenna supplied at its focal point by a FAFR source network with an analog or digital BFN; or an on-board function requiring the amplitude / phase pairing of several channels between them;
    and when the telecommunication payload is distributed over a satellite and a ground beam-forming station, the radio frequency multi-channel system is an active satellite antenna in Rx reception mode with effective beam formation on the ground GBBF; or an active satellite antenna in Tx transmission mode with effective formation of beams on the ground GBBF, with or without an MPA or MPPA function entirely on board or with or without an MPA or MPPA function whose input Butler matrix is distributed on the ground .
    [12" id="c-fr-0012]
    12 Method for calibrating a radiofrequency multichannel subsystem according to any one of claims 1 to 11 in which the fourth step (310) is carried out directly on board the satellite or on the ground.
    [13" id="c-fr-0013]
    13. Calibration system for a radio frequency multi-channel subsystem (12; 32; 52; 72; 102; 204) of a telecommunications payload, the payload being fully included in and on board a satellite or distributed over a satellite and a ground beam-forming station, the calibration taking place while the payload is in operation, the multi-channel subsystem (12; 32; 52; 72; 102; 204) comprising:
    .- a first integer N, greater than or equal to 2, of input access channels, and .- a second integer M, greater than or equal to 2, of output access channels, and .- a set (26; 46; 66; 96; 126) of at least two internal channels, each formed of a chain of radiofrequency components of the same architecture, or distributing the same input signal supplied by an input access channel on several output access channels, ie concentrating several input signals respectively supplied by several input access channels on the same output access channel; and
    The calibration system comprising a first device (212) for injecting an analog or digital calibration signal at a predetermined injection point of an input access channel or at several predetermined points each associated with a channel different entry access; and a second device (214) for sampling the calibration signal injected and propagated at a predetermined sampling point of an output access channel or at several predetermined sampling points each associated with a different output access channel;
    a third digital computing device (216), formed by one or more electronic computers, and configured to:
    .- generate a digital calibration signal corresponding to the digital or analog version of the calibration signal injected by the first device; and .- extract the calibration signal injected from the signal or signals sampled at the predetermined sampling point of an output access channel or at the predetermined sampling points each associated with a different output access channel and the generated calibration signal;
    .- estimate amplitude and / or phase differences between the internal channels of the multi-channel subsystem from the calibration signal injected as a reference and from the extracted calibration signal (s); and correct amplitude and / or phase deviations by controlling one or more means for correcting said deviations when one or more of said deviations exceed a predetermined threshold;
    the calibration system being characterized in that the calibration signal injected is a “CHIRP” or chirp type signal.
    [14" id="c-fr-0014]
    14. The system for calibrating a radiofrequency multichannel subsystem as claimed in claim 13, in which the injected calibration signal is a signal of linear complex periodic “CHIRP” type s (t) of the form s (t) = A. exp {/. φ (ΐ)}, the instantaneous frequency f (t), defined by the equations J v 7 2π dt Tl 'evolving according to a periodic function of sawtooth type repeating according to a time period T1 a frequency ramp pattern varying linearly between a first frequency value F1 and a second frequency value F2, the first frequency value F1 being equal to F ce - BWc * ir v e t the second frequency value F2 being equal to F ce +, F ce denoting a frequency predetermined central unit and BW chtrp designating the bandwidth of the CHIRP; and the frequency positioning of the injected calibration signal of the CHIRP type is independent of the frequency plan of the traffic carriers.
    [15" id="c-fr-0015]
    15. Calibration system of a radiofrequency multichannel subsystem according to any one of claims 13 to 14 in which the first and second devices (212; 214) are configured to generate and inject calibration signals at a point of predetermined injection of an input access channel or at several predetermined points each associated with a different input access channel, and the calibration signals injected are signals of the “CHIRP” type or chirps of the same width band centered at different central frequencies regularly distributed over the communication band of the traffic carriers.
    [16" id="c-fr-0016]
    16. A system for calibrating a radiofrequency multichannel subsystem according to any one of claims 13 to 15 in which when the telecommunications payload is fully included in and on board a satellite, the radiofrequency multichannel system is an MPA comprising two Butler matrices, with the Butler matrix of digital or analog input, without BFN beamforming network, integrated within an active or not antenna; or an MPA with a BFN beam forming network at digital or analog input and a Butler matrix at output, integrated within an active or not antenna; or an MPPA parallel multiport amplifier comprising amplifiers paralleled inside an MPA, integrated within an active or not antenna; or a semi-active antenna called "Multimatrix" with reflector, with or without MPA; or an active antenna of the DRA direct radiation network type or a sub-reflector antenna supplied by an AFSRA source network or a reflector antenna supplied at its focal point by a FAFR source network with an analog or digital BFN; or an on-board function requiring the amplitude / phase pairing of several channels between them;
    and when the telecommunication payload is distributed over a satellite and a ground beam-forming station, the radio frequency multi-channel system is an active satellite antenna in Rx reception mode with effective beam formation on the ground GBBF, or an active satellite antenna in mode Tx emission with effective beam formation on the GBBF ground, with or without an MPA function or
    MPPA entirely on board or with or without an MPA or MPPA function whose input Butler matrix is distributed on the ground.
    类似技术:
    公开号 | 公开日 | 专利标题
    EP3522372A1|2019-08-07|Method and system for calibrating a radiofrequency multi-channel subsystem of a telecommunications payload
    EP2795813B1|2016-05-25|Method and system for estimating a path-length difference of a target signal transmitted by a spacecraft or aircraft
    CA2850797C|2021-11-02|Calibration process for a multiport amplifier, multiport amplifier allowing such a process to be implemented and satellite including such an amplifier
    EP2386875A1|2011-11-16|Verteiltes Entfernungsmesssystem für die Lokalisierung eines geostationären Satelliten
    EP3188399B1|2018-03-21|Ibfd transceiver module with non-reciprocal frequency transposition
    EP2762912B1|2016-11-02|Device and method for collecting data for locating a source of interference
    FR3007587A1|2014-12-26|METHOD AND SYSTEM FOR MONITORING A SATELLITE TRANSFER PHASE FROM AN INITIAL ORBIT TO A MISSION ORBIT
    EP3229383B1|2021-02-24|A dynamic calibration system and method within a satellite payload.
    FR2950497A1|2011-03-25|USEFUL LOAD FOR MULTIFACEAL SATELLITE
    EP2959308B1|2017-06-28|Method and system for estimating the direction of arrival of a target signal relative to a satellite
    EP3286851B1|2020-10-28|Generation by a satellite of a signal of a second type of polarization by two transponders adapted to process signals polarizedaccording to a first type of polarization.
    EP3706238A1|2020-09-09|Ground calibration system of a payload of a satellite
    CA3003495C|2019-06-18|Method and device for suppressing interfering signals in a satellite payload signal
    FR3041103A1|2017-03-17|METHOD AND SYSTEM FOR SATELLITE ATTITUDE ESTIMATION USING MEASUREMENTS CARRIED OUT BY SOIL STATIONS
    EP3254380A1|2017-12-13|Method and system for suppressing a parasite signal received by a satellite payload
    FR3094589A1|2020-10-02|SYSTEM AND METHOD FOR ESTIMATING A SATELLITE ANTENNA POINTING ERROR
    EP2997668B1|2017-05-24|Phase difference measure of a signal received from a satellite or aircraft for its localisation using two receivers with generation of a receiver calibration signal
    FR3004812A1|2014-10-24|DEVICE FOR CALIBRATING A SATELLITE POSITIONING RECEIVER
    同族专利:
    公开号 | 公开日
    US20190238176A1|2019-08-01|
    CA3032132A1|2019-08-01|
    EP3522372A1|2019-08-07|
    FR3077448B1|2021-07-02|
    US10581482B2|2020-03-03|
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    CN1547333A|2003-11-28|2004-11-17|中兴通讯股份有限公司|A broad beam forming method for intelligent antenna base station|
    US20100156528A1|2007-05-04|2010-06-24|Alan David Couchman|Multiport amplifiers in communications satellites|
    US20120280748A1|2009-10-27|2012-11-08|Thales|Multi-port amplification device that self-compensates in the presence of traffic|
    US20150249462A1|2011-06-16|2015-09-03|Spatial Digital Systems, Inc.|System for processing data streams|
    US9621254B2|2012-09-21|2017-04-11|Spatial Digital Systems, Inc.|Communications architectures via UAV|
    FR3005381B1|2013-05-03|2015-05-01|Thales Sa|METHOD OF CALIBRATING A MULTIPORT AMPLIFIER, MULTI-PORT AMPLIFIER FOR IMPLEMENTING SUCH A METHOD, AND SATELLITE COMPRISING SUCH AMPLIFIER|
    US9885773B2|2015-03-07|2018-02-06|Verity Studios Ag|Distributed localization systems and methods and self-localizing apparatus|FR3067535A1|2017-06-09|2018-12-14|Airbus Defence And Space Sas|TELECOMMUNICATION SATELLITE, BEAM FORMING METHOD, AND METHOD FOR MANUFACTURING A SATELLITE LOAD|
    FR3073347B1|2017-11-08|2021-03-19|Airbus Defence & Space Sas|SATELLITE PAYLOAD INCLUDING A DOUBLE REFLECTIVE SURFACE REFLECTOR|
    CN113067590A|2019-12-30|2021-07-02|华为技术有限公司|Wireless device, method and related equipment|
    法律状态:
    2019-01-25| PLFP| Fee payment|Year of fee payment: 2 |
    2019-08-02| PLSC| Publication of the preliminary search report|Effective date: 20190802 |
    2020-01-27| PLFP| Fee payment|Year of fee payment: 3 |
    2021-01-26| PLFP| Fee payment|Year of fee payment: 4 |
    2022-01-27| PLFP| Fee payment|Year of fee payment: 5 |
    优先权:
    申请号 | 申请日 | 专利标题
    FR1800105A|FR3077448B1|2018-02-01|2018-02-01|METHOD AND SYSTEM FOR CALIBRATION OF A RADIOFREQUENCY MULTI-CHANNEL SUBSYSTEM OF A TELECOMMUNICATIONS PAYLOAD|
    FR1800105|2018-02-01|FR1800105A| FR3077448B1|2018-02-01|2018-02-01|METHOD AND SYSTEM FOR CALIBRATION OF A RADIOFREQUENCY MULTI-CHANNEL SUBSYSTEM OF A TELECOMMUNICATIONS PAYLOAD|
    US16/261,259| US10581482B2|2018-02-01|2019-01-29|Method and system for calibrating a radiofrequency multichannel subsystem of a telecommunications payload|
    EP19154079.8A| EP3522372A1|2018-02-01|2019-01-29|Method and system for calibrating a radiofrequency multi-channel subsystem of a telecommunications payload|
    CA3032132A| CA3032132A1|2018-02-01|2019-01-31|Method and system for calibrating a radiofrequency multichannel subsystem of a telecommunications payload|
    [返回顶部]