Calibration method for an AESA-type phased-array transmitting antenna and associated calibration system

Abstract

Method for calibrating an AESA phased-array transmitting antenna and associated calibration system. The present invention relates to a method for calibrating a transmitting array antenna, comprising the following steps: - selection (110) of at least one transmitting radiating element to be tested; - formation (115) of an elementary signal to be transmitted by each transmitting radiating element to be tested by injecting a calibration signal; - introduction (120) of a particular modulation into the elementary signal to be transmitted by each transmitting radiating element to be tested; - transmission (130) of a beam of elementary signals; - reception (140) by a receiving radiating element of a signal; - extraction (150) of the received signal from an emitted elementary signal corresponding to the transmitting radiating element to be tested; - comparison (155) of the extracted elementary signal with the emitted elementary signal;- correction (160) of calibration parameters of the emission radiating element to be tested. Figure for the abbreviation: Figure 5;

Description

TITLE :

[0001] Method for calibrating an AESA-type phased-array transmitting antenna and associated calibration system

[0002] The present invention relates to a method for calibrating an AESA type phase-controlled transmitting array antenna.

[0003] The present invention also relates to a calibration system associated with such a method.

[0004] In particular, the technical field of the invention relates to phased array antennas and especially to AESA type array antennas (from the English "Active Electronically Scanned Array").

[0005] In a manner known per se, two-dimensional pointing along a direction by such an antenna is obtained by applying phase (and / or delay) weights and appropriate amplitudes to the radiating elements.

[0006] These amplitudes and phases can be generated by digital control of analog components, also called ABF components (from the English "Analog Beam Forming"). These components can include various amplifiers with controllable gain, programmable phase shifters, programmable delay lines, etc.

[0007] The type of antenna mentioned above is usable in radiocommunication in general (for example of Satcom GEO, MEO, LEO, X, Ku, Ka bands, etc.) as well as in radars.

[0008] For this type of antenna, there is a need to guarantee the levels of secondary lobes with respect to radiocommunication standards. To this end, it is generally necessary to calibrate the various elements forming the antenna following variations that have occurred during its life cycle.

[0009] These variations can occur in the different components of the antenna and can be caused by multiple reasons. Among these reasons, we can mention in particular external conditions (temperature, humidity, etc.), power supply, vibrations, aging of materials, etc.

[0010] The prior art already offers some methods for calibrating this type of antenna.

[0011] Thus, one of these methods consists of performing a purely factory calibration, hoping that this calibration will last for the entire lifespan of the antenna. Another calibration method consists of determining maintenance periods during which the antenna is not operational.

[0012] It is therefore understood that the methods of the state of the art are not satisfactory and in particular do not allow regular calibration of the network antenna without interrupting its operation.

[0013] One of the objectives of the present invention is to provide regular calibration of an AESA-type array antenna throughout its lifecycle without interrupting its nominal operation. Furthermore, the calibration according to the invention can be implemented by the array antenna itself, i.e., autonomously.

[0014] To this end, the invention relates to a method for calibrating an AESA-type phased-array transmitting antenna, the transmitting array comprising:

[0015] - a plurality of radiating emission elements;

[0016] - at least one radiating receiving element arranged among the radiating elements emission;

[0017] - an analog beamforming module capable of forming for each element radiating an elementary nominal signal to be emitted from a radio frequency signal;

[0018] - a modem capable of generating the radio frequency signal;

[0019] The process comprises the following steps:

[0020] - selection of at least one radiating emission element to be tested;

[0021] - formation of an elementary signal to be emitted by a radiating emission element to be tested by injecting a calibration signal in place or in addition to the nominal elementary signal to be emitted by this radiating emission element to be tested;

[0022] - introduction of a particular modulation in the elementary signal to be emitted by radiating emission element to be tested;

[0023] - emission of a beam of elementary signals by the set of elements radiating emission;

[0024] - reception by a receiving radiating element of a signal formed by the emitted beam via a coupling between the radiating emission element to be tested and this radiating reception element;

[0025] - extraction of the received signal from an elementary emitted signal corresponding to the element radiating emission to be tested using the particular modulation;

[0026] - comparison of the extracted elementary signal with the elementary signal emitted by the radiating emission element to be tested;

[0027] - correction of calibration parameters of the radiating emission element to be tested based on said comparison.

[0028] According to other advantageous aspects of the invention, the method comprises one or more of the following features, taken individually or in all technically possible combinations:

[0029] - the steps of the process are repeated for each radiating emission element of the transmitting network antenna to be calibrated;

[0030] - the steps of the process are repeated during the operation of the network antenna emission in nominal mode;

[0031] -the introduction of the particular modulation includes the introduction into the elementary signal to be emitted by the radiating emission element to be tested of a phase and / or delay and / or amplitude code;

[0032] - when, during the selection step, several radiating emission elements are are selected to test, the other steps of the process are implemented in parallel for each of the selected radiating emission elements to be tested using a modulation specific to each of the radiating emission elements to be tested;

[0033] - the calibration parameters of a radiating emission element include phase and / or delay and / or amplitude weights associated with this radiating emission element;

[0034] - the receiving radiating element operates at the same frequency as the element radiating emission to be tested;

[0035] - the radiating receiving element is arranged according to one of the following possibilities:

[0036] - in the same pattern as the radiating emission element to be tested;

[0037] - in the same slab the radiating emission element to be tested but in a pattern different ;

[0038] - in a slab other than the slab of the radiating emission element to be tested.

[0039] - the step of comparing the extracted elementary signal with the emitted elementary signal by the radiating emission element to be tested includes a measurement of the phase difference and / or delay and / or amplitude between the calibration signal emitted and that received via coupling between the radiating emission element to be tested and the radiating reception element;

[0040] - the calibration signal is injected into a nominal signal to be emitted by the antenna transmission network at the modem level or at the level of a pattern including the radiating transmission element to be tested.

[0041] The present invention also relates to a calibration system for an AESA type phase-controlled transmitting array antenna, comprising a calibration modem; a receiving circuit connecting at least one receiving radiating element to the calibration modem and a control unit.

[0042] The calibration system is configured to implement at least some steps of the process as defined above.

[0043] These features and advantages of the invention will become apparent from the following description, given solely by way of non-limiting example, and made with reference to the accompanying drawings, in which:

[0044] - [Fig. 1] [Fig. 1] is a schematic view of a calibration system for a transmitting network antenna to be calibrated, according to the invention;

[0045] - [Fig.2] [Fig.2] is a schematic view of an antenna transmission module transmission network of the [Fig.l];

[0046] - [Fig.3] [Fig.3] is a schematic view of a motif forming part of the module emission of the [Fig.2];

[0047] - [Fig.4] [Fig.4] is a schematic view of a control unit associated with a group of radiating elements of the pattern of [Fig.3];

[0048] - [Fig. 5] [Fig. 5] is a flowchart of a calibration process implemented at less partially by the calibration system of [Fig. 1]; and

[0049] - [Fig.6] [Fig.6] is a diagram illustrating the implementation of at least some steps of the process of [Fig.5].

[0050] Fig. 1 illustrates a calibration system 10 for a transmitting array antenna 11 to be calibrated. This calibration system 10 is integrated into the antenna 11.

[0051] The transmitting array antenna 11 is a phase-controlled array antenna of the AESA (Active Electronically Scanned Array) type. This array antenna 11 includes a transmitting assembly 25 adapted to transmit radio signals to another antenna.

[0052] The transmission assembly 25 includes a transmission module 31 for transmitting a beam of elementary signals, a beamforming module 32 for forming a beam of elementary signals from a radio frequency signal, a modem 33 for generating the radio frequency signal from the useful data and a control module 34 for controlling the operation of the components of the transmission assembly 25.

[0053] The control module 34 is, for example, of the ACU (Antenna Control Unit) type, which can be used to point the transmitting antenna 11 in the desired direction. This module 34 is specifically configured to control the operation of the beamforming module 32 and the transmitting module 31.

[0054] The control module 34 includes, in particular, a calibration table comprising calibration parameters for each radiating element, which are explained in more detail later. These calibration parameters include, in particular, phase (and / or delay) and amplitude weights to be applied to the corresponding radiating element when emitting an elementary signal.

[0055] Modem 33, for example, is known in itself. In particular, it allows the generation of a radio frequency signal from useful data. The useful data is the data to transmit via the transmitting antenna 11 which are generated for example by an external computing unit.

[0056] Fig. 2 illustrates an example of the respective arrangement of the emission module 31 and the beamforming module 32.

[0057] In the example shown in [Fig. 2], the transmitting module 31 comprises a plurality of tiles 40-1, ..., 40-N. The tiles 40-1, ..., 40-N have different physical entities arranged, for example, on a support for the transmitting antenna 11, separately from one another. The tiles 40-1, ..., 40-N are, for example, substantially identical to each other. By way of example, the number N of tiles varies, for example, from 1 to 10.

[0058] Each slab 40-1, ..., 40-N comprises a plurality of patterns 41-1, ..., 41-K arranged on an outer surface of that slab. As can be seen in [Fig. 2], these patterns form, for example, at least two rows and at least two columns on the surface of the corresponding slab. According to other examples, the radiating elements can be arranged in a circle or have any other arrangement, and the patterns can be adapted to this arrangement. The size of a pattern can be chosen to avoid intra-pattern calibration of the radiating element type, for example, on a radiating element-by-radiating element basis. The number K of patterns per slab varies, for example, from 4 to 16.

[0059] Each motif 41-1, ..., 41-K, for example, has a printed circuit board on which a plurality of radiating elements are arranged. According to another example, the radiating elements can be horns. Motifs 41-1, ..., 41-K are, for example, substantially similar to each other. Thus, hereafter, only motif 41-1 will be explained in more detail with reference to [Fig. 3].

[0060] With reference to [Fig. 3], the motif 41-1 comprises a plurality of radiating elements 42-1, ..., 42-M. In the example in this figure, the number L of radiating elements is 64. The radiating elements 42-1, ..., 42-M form a matrix on the corresponding motif 41-1. Furthermore, the radiating elements 42-1, ..., 42-M are grouped into a plurality of groups within the same motif 41-1. In the example in [Fig. 3], each group consists of four adjacent radiating elements 42-1, ..., 42-M. In this example, 16 groups of radiating elements are thus formed. Each group of radiating elements is controlled by the same control unit, as will be explained in more detail later.

[0061] The beamforming module 32 is an analog module for generating an elementary signal to be transmitted for each radiating element 42-1, ..., 42-M from the radio frequency signal delivered by the modem 33.

[0062] To achieve this, the beamforming module 32 includes an emission conversion unit 45, for example of the BUC (Block Up Converter) type, enabling the conversion of the frequency of the radio frequency signal delivered by the modem 33 in a frequency to transmit in a range, such as for example the "L", "Ku" or "Ka" band.

[0063] The beamforming module 32 further includes at least three levels of signal splitters for generating an elementary signal for each radiating element 42-1, ..., 42-M. These splitters have controllable gain amplifiers and programmable phase shifters (and / or delays) for generating a beam of elementary signals according to techniques known per se.

[0064] In particular, as can be seen in [Fig. 2], a first level of separators comprises a single separator 51 for separating the signal delivered by the transmitting conversion unit 45 between the tiles 40-1, ..., 41-N. A second level of separators comprises N separators 52-1, ..., 52-N. Each separator of the second level 52-1, ..., 52-N is associated with one of the tiles 40-1, ..., 40-N and allows the signal received by that tile to be separated between the different patterns 41-1, ..., 41-K. Finally, a third level of separators comprises, for each pattern 41-1, ..., 41-K in each tile 40-1, ..., 40-N, a separator 53 for separating the signal delivered to the corresponding pattern between the different groups of radiating elements forming that pattern. Such a separator 53 is visible in [Fig. 3].

[0065] The beamforming module 32 further includes a control unit 55 associated with each group of radiating elements and enabling the generation of an elementary signal for each radiating element of this group from the signal delivered by the corresponding separator 53 of the third level.

[0066] An example of such a control unit 55 is shown in [Fig. 4]. According to this example, the control unit 55 is associated with a group of radiating elements consisting of four radiating elements 42-1, ..., 42-M. Thus, from a signal S delivered by the corresponding separator 53, this unit 55 makes it possible to generate 4 elementary signals for the corresponding radiating elements 42-1, ..., 42-M, according to a predetermined logic.

[0067] As previously stated, the calibration system 10 is integrated into the antenna 11.

[0068] In particular, the calibration system 10 allows a calibration signal to be injected into a nominal signal to be emitted by the antenna 11 and then, via mutual coupling between at least some radiating elements, this calibration signal to be received and compared with the calibration signal initially emitted. The calibration is performed per radiating element, and to distinguish the calibration signal emitted by a given radiating element, a specific modulation is introduced into the elementary signal to be emitted by that radiating element.

[0069] To this end, the calibration system 10 includes a calibration modem 57 integrated, for example, in the control module 34 of the antenna 11 and enabling to generate a calibration signal to be emitted by one or more radiating elements. According to one embodiment, this calibration modem 57 is capable of injecting the calibration signal into the radio frequency signal generated by the modem 33. For this purpose, a signal summation unit can be arranged upstream of the transmission conversion unit 45. In such a case, the calibration signal is summed with the nominal signal to be emitted by the antenna 11. According to another embodiment, the calibration modem 57 is capable of injecting the calibration signal downstream of each separator 52-1, ..., 52-N into the signal intended for the pattern corresponding to the radiating element to be tested, or downstream of each separator 53 into the signal intended for the group of radiating elements corresponding to the radiating element to be tested.

[0070] The calibration system 10 further comprises a receiving circuit connecting at least one radiating element of each pattern 41-1, ..., 41-K to the calibration modem 57. In particular, such a radiating element is hereafter referred to as a receiving radiating element and is selected from among the radiating elements 42-1, ..., 42-M described previously. In the example of [Fig. 3], a grouping of four receiving radiating elements 58 is selected from the set of radiating elements 42-1, ..., 42-M of pattern 41-1.

[0071] Advantageously, the receiving radiant elements 58 chosen in a pattern correspond to the same group of radiating elements and are therefore controlled by the same control unit 55. Possibly, only one of the four receiving radiant elements is used.

[0072] Even more advantageously, this control unit 55 is capable of switching the operating mode of the corresponding radiating elements 58 between reception and transmission modes. In certain embodiments, each radiating element 42-1, ..., 42-M can be switched between reception and transmission modes by the control unit 55 associated with that radiating element. The receiving and transmitting radiating elements 58 operate at the same frequency.

[0073] It is clear that the respective positions of the receiving radiating elements 58 and the transmitting radiating elements determine the coupling between these elements. This coupling allows at least some receiving radiating elements 58 to receive elementary signals from at least some transmitting radiating elements. Advantageously, according to the invention, the coupling between each pair of radiating elements is known and, for example, stored in a dedicated database.

[0074] To connect the receiving radiating elements 58 to the receiving circuit, each motif 41-1, ...,41-K includes for example a suitable Rx connector.

[0075] The receiving circuit of the calibration system 10 further includes a receiving conversion unit 59. As can be seen in [Fig. 2], this receiving conversion unit 59 is integrated into the beamforming module 32 and its role is inverse to that of the transmitting conversion unit 45. In particular, the receiving conversion unit 59 is for example also of type BUC and allows to convert signals received by the receiving circuit into radio frequency signals compatible with the calibration modem 57. In one embodiment, the receiving conversion unit 59 and the transmitting conversion unit 45 form a common unit since the transmission and reception take place at the same frequency.

[0076] Finally, the calibration system 10 includes a control unit 60 capable of controlling the operation of the calibration modem 57 and the receiving circuit. This control unit 60 is integrated, for example, into the control module 34 of the antenna 11. The control unit 60 also allows for the introduction of a specific modulation into the elementary signal emitted by each radiating transmitting element, as will be explained in more detail later. To this end, the control unit 60 can be connected to each splitter at each level of splitters as well as to the control unit 55 of each group of radiating elements.

[0077] The calibration system 10 is capable of implementing at least some steps of the calibration process of the transmitting array antenna 11. This process will now be described in detail with reference to [Fig.5] showing a flowchart of its steps.

[0078] The purpose of this method is to calibrate the radiating emission elements during the nominal operation of the transmitting array antenna 11. In other words, the steps described below are implemented during the transmission of useful data by the transmitting antenna 11 without significant degradation of the quality of its service.

[0079] During an initial step 110, the calibration system 10 selects an emission radiating element to be tested.

[0080] The selection can be made, for example, according to a predetermined rule. This rule can, for example, include the selection of a radiating element according to an order defined by its position on the slab and / or the corresponding pattern.

[0081] According to one embodiment, during this step, the calibration system 10 selects several radiating emission elements to be tested. These radiating emission elements to be tested are, for example, from the same group or are adjacent. In such a case, steps 115 to 160 described below are implemented in parallel for each of the selected radiating emission elements to be tested, using a specific modulation specific to each radiating emission element to be tested. The calibration signal therefore remains the same for all the radiating emission elements to be tested. Step 130 also remains the same for all the radiating emission elements to be tested.

[0082] In a subsequent step 115, the calibration modem 57 generates a calibration signal and injects it in place of, or in addition to, the nominal elementary signal to be emitted by the radiating emission element under test. Thus, henceforth, the elementary signal to be emitted by the radiating emission element under test is understood to mean the calibration signal alone or combined with the nominal elementary signal to be emitted by that element.

[0083] According to various embodiments, the calibration signal can be injected at the modem 33, at any previously described splitter, or at the control unit 55 associated with the radiating emission element to be tested. Depending on the injection point, the elementary signals to be emitted by at least some radiating emission elements can then be summed or replaced by the calibration signal.

[0084] In a subsequent step 120, the control unit 60 introduces a particular modulation into the elementary signal to be emitted by the radiating emission element to be tested. This can be done, for example, by directly controlling the control unit 55 associated with the radiating emission element to be tested.

[0085] Furthermore, various techniques can be used to introduce this particular modulation only in one of the radiating emission elements among the set of radiating emission elements controlled by the corresponding control unit 55. For example, it is possible to attenuate the power level on radiating elements other than the radiating emission element under test.

[0086] Another technique may be to emit several different specific modulations in parallel, one for each radiating element of the group under consideration. In such a case, the elementary signals from the radiating elements other than the emitting radiating element to be tested may be rejected or measured during step 150 described below, using these specific modulations.

[0087] The particular modulation may feature an amplitude-phase code, or amplitude / delay or combined amplitude-phase-delay code which is superimposed on the elementary signal formed for the radiating emission element to be tested in the previous step.

[0088] By way of example, the particular modulation introduced into the elementary signal at this stage may be a code having good autocorrelation and / or crosscorrelation properties.

[0089] In a subsequent step 130, the transmitting array antenna 11 emits a beam of elementary signals (i.e. nominal elementary signals except those which have been modified by the calibration signal and possibly by the particular modulation) by the set of radiating elements 42-1, ..., 42-M.

[0090] In a subsequent step 140, the calibration modem 57 uses one of the receiving radiating elements 58 to receive a signal formed from the emitted beam.

[0091] The selection of this receiving radiating element 58 is made according to its position relative to the emitting radiating element to be tested. For example, the selection is made so that the receiving radiating element 58 has maximum coupling with the emitting radiating element to be tested.

[0092] According to various examples of the invention, the receiving radiating element 58 is selected so as to be:

[0093] - in the same pattern as the radiating emission element to be tested; or

[0094] - in the same slab as the radiating emission element to be tested but in a different pattern; or

[0095] - in a slab other than the slab of the radiating emission element to be tested.

[0096] According to one embodiment, the selection of the receiving radiating element 58 is done dynamically from among the set of radiating elements 42-1, ..., 42-M. In such a case, the calibration system 10 can, for example, select one of the radiating elements 42-1, ..., 42-M other than the radiating element to be tested and then switch it into the receiving mode.

[0097] According to another embodiment, the selection of the receiving radiating element 58 is made from a predetermined set of radiating elements operating in receive mode. This set is, for example, statically predetermined, for example, for the entire life cycle of the antenna. In this latter case, the elements of this set always operate, for example, in receive mode.

[0098] In certain embodiments, the receiving radiant element 58 may be part of a group of receiving radiant elements. In such a case, only this element radiating onto the group, for example, may be used, the others being attenuated to the maximum or each of the receiving radiant elements being used.

[0099] In a subsequent step 150, the control unit 60 separates the elementary signal received from the radiating emission element to be tested from the other elementary signals by means of the application of the code corresponding to the particular modulation introduced during the emission.

[0100] The implementation of steps 120 to 150 is illustrated schematically in [Fig.6].

[0101] In particular, in this figure, the element Rxk(p,q) corresponds to the receiving radiating element 58, the element Txk(i,j) corresponds to the radiating element to be tested, and the element Txu(r,s) corresponds to any other emitting radiating element exhibiting mutual coupling with the element Rxk(p,q). It is clear that in practice, several Txu(r,s) elements exhibit mutual coupling with the element Rxk(p,q). However, to facilitate understanding of [Fig. 6], only one Txu(r,s) element is shown there.

[0102] The nominal elementary signal to be emitted by the two elements Txk(i,j) and Txu(r,s) is controlled respectively by the SPI_k control bus introducing the CTx(i,j) code, and SPI_u on [Fig. 6]. The signal Ka_Txk, the sum of the nominal signal and the calibration signal, or simply the calibration signal, is multiplied by the nominal signal CTx(i,j) of the element Txk(i,j). Furthermore, in the example in this figure, the signal Ka_Txu, the sum of the nominal signal and the calibration signal, like Ka_Txk, or simply the nominal signal, is not modulated by any particular modulation.

[0103] The elementary signals emitted by the two Tx elements then form a beam of elementary signals which is received by the receiving radiating element Rxk (p,q) through mutual coupling with each of the illustrated Tx elements. Such mutual coupling is denoted in [Fig. 6] as MC(ij,pq) and MC(rs,pq).

[0104] Finally, in the example of [Fig.6], the code CRx(p,q) is used to extract from the emitted beam the elementary signal emitted by the radiating element Txk(i,j).

[0105] In another example, several different CRx(p,q) codes are used, if several radiating transmitting elements are tested in parallel, but applied and distributed over several radiating receiving elements, via the SPI_k' control, or applied in parallel during calibration demodulation.

[0106] In a subsequent step 155, the control unit 60 compares the elementary signal extracted in the previous step with the elementary signal emitted by the radiating element under test. This is possible because the calibration modem 57 knows the emitted calibration signal and the time of its emission. This comparison may include, for example, a measurement of the phase difference, delay, and amplitude between the calibration signal that was emitted and the one received via coupling between the radiating element under test and the receiving radiating element 58, allowing the analysis of variations with respect to the calibration table.

[0107] During this step, several measurements of varying durations of the code length on the extracted signal can, for example, be made to improve accuracy. The number of measurements is advantageously greater than 1 and less than, for example, 10 or 100.

[0108] In the next step 160, the control unit 60 analyzes the previous comparison and corrects the calibration parameters of the radiating element to be tested. In particular, these parameters are corrected, for example, so as to minimize the difference between the calibration signal that was emitted and that received.

[0109] Then, steps 110 to 160 are repeated with respect to another radiating element.

[0110] It is then understood that the present invention has a number of advantages.

[0111] In particular, the invention makes it possible to calibrate a transmitting array antenna throughout its lifecycle without degradation of the service provided. Indeed, during calibration, the transmitting array antenna operates normally and the calibration signal introduced at one or more radiating elements does not degrade the service. The quality of service provided by this antenna is measured. A specific modulation is used to distinguish the elementary signals emitted by different radiating elements, thus allowing each radiating element to be calibrated individually. Furthermore, the method according to the invention can be applied an unlimited number of times to all radiating elements. Each calibration signal introduced can be controlled and varied, for example, to adapt the calibration to a particular type of variation that may occur throughout the lifecycle of the network antenna. This calibration can be performed autonomously by the antenna, that is, without the use of any other means. Finally, thanks to the invention, it is also possible to test several radiating transmitting elements in parallel. To do this, it is sufficient to apply a specific modulation specific to each of the radiating elements to be tested.

Claims

Demands

1. A method for calibrating an AESA phase-controlled transmitting array (11), the transmitting array (11) comprising: - a plurality of transmitting radiating elements; - at least one receiving radiating element (58) disposed among the transmitting radiating elements; - an analog beamforming module (32) capable of forming for each transmitting radiating element a nominal elementary signal to be transmitted from a radio frequency signal; - a modem (33) capable of generating the radio frequency signal; the method comprising the following steps: - selection (110) of at least one transmitting radiating element to be tested; - formation (115) of an elementary signal to be transmitted by the transmitting radiating element to be tested by injecting a calibration signal in place of or in addition to the nominal elementary signal to be transmitted by this transmitting radiating element to be tested;- introduction (120) of a particular modulation in the elementary signal to be emitted by the radiating emission element to be tested; - emission (130) of a beam of elementary signals by the set of radiating emission elements (42-1, 42-M); - reception (140) by the receiving radiating element (58) of a signal formed from the emitted beam via coupling between the radiating emission element to be tested and this receiving radiating element (58); - extraction (150) of the received signal from an elementary signal emitted corresponding to the radiating emission element to be tested using the particular modulation; - comparison (155) of the extracted elementary signal with the elementary signal emitted by the radiating emission element to be tested; - correction (160) of calibration parameters of the radiating emission element to be tested as a function of said comparison.

2. A method according to claim 1, wherein the steps of the method are repeated for each radiating emission element of the transmitting array antenna (11) to be calibrated.

3. A method according to any one of the preceding claims, wherein the steps of the method are repeated during the operation of the transmitting array antenna (11) in nominal mode.

4. A method according to any one of the preceding claims, wherein the introduction of the particular modulation includes the introduction into the elementary signal to be emitted by the radiating emission element to be tested of a phase and / or delay and / or amplitude code.

5. A method according to any one of the preceding claims, wherein when, during the selection step (110), several radiating emission elements to be tested are selected, the other steps of the method are carried out in parallel for each of the selected radiating emission elements to be tested using a modulation specific to each of the radiating emission elements to be tested.

6. A method according to any one of the preceding claims, wherein the calibration parameters of an emitting radiating element include phase and / or delay and / or amplitude weights associated with that emitting radiating element.

7. A method according to any one of the preceding claims, wherein the receiving radiating element (58) operates at the same frequency as the transmitting radiating element to be tested.

8. A method according to any one of the preceding claims, wherein the receiving radiating element (58) is arranged in one of the following ways: - in the same pattern (41-1, ..., 41-K) as the emitting radiating element to be tested; - in the same slab (40-1, ..., 40-N) as the emitting radiating element to be tested but in a different pattern (41-1, ..., 41-K); - in a slab (40-1, ..., 40-N) other than the slab of the emitting radiating element to be tested.

9. A method according to any one of the preceding claims, wherein the comparison step (155) of the extracted elementary signal with the elementary signal emitted by the radiating emission element to be tested comprises a measurement of the phase difference and / or delay and / or amplitude between the calibration signal emitted and that received via coupling between the radiating emission element to be tested and the radiating reception element (58).

10. 15 Method according to any one of the preceding claims, wherein the calibration signal is injected into a nominal signal to be emitted by the transmitting network antenna (11) at the modem (33) or at a pattern (41-1, ..., 41-K) comprising the emitting radiating element to be tested.

11. Calibration system (10) of an AESA-type phase-controlled transmitting array antenna (11) being configured to implement all the steps of claim 1.

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