Ultra-compact e / h hybrid combiner, notably for a single-reflector mfb antenna

Description

[0001] The invention relates to the general field of communications satellites and in particular to the multi-beam antennas equipping these satellites.

[0002] The invention relates more specifically to the formation of antenna beams in the context of the use of MFB antennas (or "Multi Feed per Beam" antennas according to the Anglo-Saxon term).

[0003] In the context of the development of current and future communication satellites, such as the V-HT multi-beam Ka satellites, the targeted geographical coverages are increasingly extensive. In addition, as the number of users and therefore the capacity required of these satellites is constantly increasing, there is an increasingly pressing need for antennas capable of radiating several hundred beams, typically a number of beams greater than five hundred.

[0004] There is also a need for antennas capable of covering geographical areas with fine resolution (small spots), i.e. capable of forming beams with a small angular aperture.

[0005] Such coverage, both dense and extensive, is incompatible, for technical reasons, with passive antenna solutions of the SFB type (i.e. "Single Feed per Beam" type according to the Anglo-Saxon term) with multiple reflectors. They are however made possible by the implementation of single-reflector MFB type antennas (i.e. "Multi Feed per Beam" type according to the Anglo-Saxon term).

[0006] A single-reflector MFB antenna solution, for transmission and reception, allowing the production of a large number of fine beams, has been developed by the applicant. This solution is based on an antenna architecture consisting of sub-arrays of 4 bipolarization elements (Tx / Rx) allowing the generation of rectangular beams using a slightly oversized reflector, a reflector whose size is typically oversized by 15%.

[0007] By using sub-networks with 4 bipolarization radiating elements (Tx / Rx), preferably four circular aperture horns, it is possible to generate, using a single reflector antenna, rectangular beams (Tx / Rx) in sufficient number to cover a given geographical area using a plurality of rectangular spots.

[0008] Such an architecture is constructed by means of an assembly of distribution modules, each comprising an RF chain (transmitter and receiver) and means ensuring the connection of the RF chain to several horns, these horns being arranged so as to be able to be combined to form a single beam.

[0009] These distribution modules form a network made up of nested meshes to which the horns are connected so that their openings are arranged in a radiating plane.

[0010] The structure and geometry of the distribution modules are defined in such a way that the horns connected to the same distribution module are arranged in such a way that the recombination of the beams of the horns connected to the same module forms a single beam, associated with a spot in the geographical area covered.

[0011] The schematic illustration of the figure 1 presents, as an example, a partial view of a single-reflector MFB antenna architecture intended to cover a geographical area divided into rectangular elementary spots (rectangular mesh of the covered area).

[0012] The MFB antenna considered here is built around a network of distribution modules 11 configured in such a way that the horns 12 associated with the same distribution module are arranged according to the vertices of a diamond, so as to be able to be combined to form a beam covering a given spot.

[0013] Such an antenna structure advantageously makes it possible to form highly focused antenna beams from radiating horns 12 having small diameter openings.

[0014] As can be seen from the schematic diagram of the figure 2 , each radiating horn of the antenna thus formed is connected, in transmission and reception, to two distribution modules corresponding to two separate beams, except for the horns covering the periphery of the geographical area, which are connected to a single module. Thus in the illustration of the figure 2 , the reception module R associated with the horn 211 is connected to the reception channels 22 and 23 corresponding to the beams n and m by the distribution modules 24 and 25.

[0015] Furthermore, each distribution module is used to ensure the distribution of the signal corresponding to the same beam on four RF chains, each chain comprising a radiating horn.

[0016] In this respect, in a known manner, a distribution module allowing the coupling in transmission of a given beam, towards the RF chains served by this beam is constituted by a power divider module formed of couplers arranged in two stages connected to each other by connection interfaces, of the waveguide type for example.

[0017] Similarly, a distribution module allowing the coupling in reception of a given beam, towards the RF chains served by this beam is constituted by a power summing module formed of couplers arranged in two stages connected to each other by connection interfaces, of the waveguide type for example.

[0018] From a structural point of view, whether it is intended for a transmission channel or a reception channel, a distribution module is structured, as illustrated in the diagram of the figure 3 , in two floors.

[0019] The first coupling stage comprises a coupler 31, while the second coupling stage comprises two couplers 32 and 33.

[0020] In the case of a distribution module placed in a beam reception path, couplers 31, 32 and 33 operate as adders.

[0021] The two couplers 32 and 33 of the second stage each perform the power summation, two by two, of the signals RX 1 to RX 4 delivered by the reception channels of the four transmission / reception modules served by a given beam.

[0022] The coupler 31, for its part, combines the summation signals delivered by the couplers 32 and 33 and delivers a sum signal RX.

[0023] Similarly, in the case of a distribution module placed in a beam transmission path, the couplers 31, 32 and 33 operate as power dividers.

[0024] The coupler 31 receives the signal to be transmitted corresponding to the beam considered and divides it into two signals transmitted to the couplers 32 and 33 respectively.

[0025] The two couplers 32 and 33 of the second stage, in turn, divide the received signal into two signals. Each coupler thus delivers to each of the transmission / reception modules to which it is connected a transmission signal corresponding to the signal carried by the transmission path of the beam in question.

[0026] Generally speaking, from an implementation point of view, the couplers 31, 32 and 33 forming a distribution module are produced in the form of cavities and connected to each other via waveguides 34.

[0027] Thus, as can be seen, the production of a single-reflector MFB antenna such as that described above requires the use, in order to produce all the necessary distribution modules, of a large number of coupling devices as well as connecting elements between the various couplers on the one hand and between these couplers and the RF chain and the horns on the other hand. For example, documents EP 3 404 766 A1, US 3 375 472 A, GB 2 313 714 A describe T-shaped hybrid combiner-dividers.

[0028] Furthermore, it can also be seen that the establishment of such distribution networks results in a significant interweaving of the different elements.

[0029] Consequently, if we take into account the compactness of the radiating source of a satellite antenna and the large number of horns that such a source can contain, the installation of all the distribution modules necessary to create a single-reflector MFB satellite antenna can prove tricky.

[0030] Currently, a solution used to optimize the space requirement of the beam distribution system consists of producing distribution modules formed from half-shell moldings assembled to form a set of cavities arranged to perform all the functions (coupling and connection) performed by the module. However, due to the nesting of the different distribution modules in such a structure, the molded elements produced require the adoption of a tiling of the half-shells with respect to each other, so that each distribution module thus produced is not physically independent of the neighboring modules. Such mechanical interdependence has the consequence of making the assembly or disassembly of a module, as well as the overall assembly, difficult.

[0031] Furthermore, the production of distribution modules in the form of molded parts constituting a highly interlocking assembly makes it difficult to integrate additional functionalities, such as deviation measurement functions, which require an appropriate combination of the signals received.

[0032] An aim of the invention is to propose equipment making it simpler and more economical in terms of space requirement to produce distribution modules such as those described above.

[0033] Another aim of the invention is to propose equipment allowing the implementation of additional functionalities such as the formation of deviation measurement lanes.

[0034] To this end, the invention relates to a compact reciprocal hybrid E / H combiner-divider, for carrying out the coupling or separation of electromagnetic waves, comprising the technical characteristics of the independent claim.

[0035] According to particular embodiments, the hybrid E / H combiner-divider comprises one or more of the following features, taken individually or in combination: each of the secondary waveguides comprises an internal conductive element placed in the cavity of the waveguide and in electrical contact with the wall of the guide, said internal conductive element being arranged inside the waveguide so as to optimize the adaptation of the impedance of the guide and the combination or division of the waves passing through the guide; the internal conductive element is a pin fixed in a substantially median position on the internal face of the upper wall of the guide; the internal conductive element is constituted by a wall projecting inside the guide, placed transversely in a substantially median position on the internal face of the upper wall of the guide, the height of said projection being substantially less than the height of the guide;the hybrid E / H combiner-divider further comprises two tertiary waveguides placed transversely relative to each of the secondary waveguides and integral with the latter, each tertiary waveguide having a parallelepipedal structure of rectangular section with two ends, a first end configured to form an input-output port and a second end forming an opening placed opposite an opening made in the side wall of each secondary waveguide opposite the dividing wall, in a substantially median position, said opening being configured to communicate each secondary waveguide with a tertiary waveguide placed transversely relative to it, so as to ensure H-plane coupling, the combiner-divider thus having an EH hybrid T-shaped structure. ;

[0036] The invention also relates to a beam distribution network for a multi-source antenna per beam (MFB) characterized in that it comprises a first group and a second group of hybrid combiners-dividers as defined above, each combiner-divider of the first group acting as a combiner being connected by its secondary ports to the reception channels of four radiating sources and to a beam reception channel by its primary port; each combiner-divider of the second group, acting as a combiner, being connected by its secondary ports to the transmission channels of four radiating sources and to a beam transmission channel by its primary port.

[0037] According to a particular embodiment, the beam distribution network for multi-source antenna per beam (MFB) comprises the following characteristics: the combiners-dividers of the first group are combiners-dividers as defined above whose auxiliary output ports are connected to a deviation measurement device.

[0038] The invention also relates to a beamforming array (BFA) antenna characterized in that it comprises a plurality of radiating sources associated in groups of four radiating sources, the reception paths and the transmission paths of the radiating sources belonging to the same group being connected respectively to the secondary ports of a combiner-divider whose primary port is connected to the reception path of a beam and to the secondary ports of a combiner-divider whose primary port is connected to the transmission path of the same beam.

[0039] The present invention proposed greatly and advantageously solves the problem of nesting the BFNs of the single-reflector solution.

[0040] The EH hybrid component according to the invention allows the combination of 4 radiating elements in a reduced footprint limited in the xy plane to the access guide.

[0041] It advantageously integrates, in the same structure, a plane divider E allowing to form a sum channel and two plane dividers H allowing to form difference channels.

[0042] It also has the property of allowing the power sharing to be adapted between the input port common to the different channels and the output ports.

[0043] It also offers the ability to perform within the network and for any spot, a deviation function (using the sum and difference channels) in addition to the TLC functions (beam formation) by combining in a single 1:6 component (one input and six outputs) two magic tees, coupled with an E-plane divider.

[0044] The characteristics and advantages of the invention will be better appreciated thanks to the following description, a description which is based on the appended figures which present: [ Fig 1 ] the illustration of an example of a combination of four radiating sources in a diamond arrangement to form a beam; [ Fig. 2 ] a schematic diagram of the interconnection of the radiating elements forming the radiating source of an MFB reflector antenna by means of distribution module modules; [ Fig. 3 ] a schematic illustration of a distribution module according to the prior art; [ Fig. 4 ] an illustration showing an overall perspective view of the distribution module according to the invention, in a basic form; [ Fig. 5 ] an illustration showing a partial view from below of the distribution module according to the invention illustrated by the figure 4 , along a plane passing through the open end of the primary waveguide; [ Fig. 6 ] an illustration showing a partial top view of the distribution module according to the invention illustrated by the figure 4 ; [ Fig. 7 ] an illustration showing an overall perspective view of the distribution module according to the invention, in a second embodiment taken as an example; [ Fig. 8 ] an illustration showing a partial perspective and transparent view of the distribution module according to the invention in the embodiment of the figure 7 ; [ Fig. 9 ] an illustration showing a top view, in transparency, of the distribution module according to the invention, in the embodiment of the figure 7 ; [ Fig. 10 ] an illustration showing a partial perspective and transparent view of the distribution module according to the invention in a third embodiment allowing the creation of deviation measurement signals; [ Fig. 11 ] an illustration showing a top view, in transparency, of the distribution module according to the invention illustrated by the figure 10 ; [ Fig. 12 ] an illustration showing a side view, in partial section, of the distribution module according to the invention in the embodiment illustrated by figure 108.

[0045] It should be noted that, in the attached figures, the same functional or structural element preferably bears the same reference symbol.

[0046] The rest of the text presents the technical characteristics of the invention based on the figures 4 And 5 which present the device in its basic version; then relying on the figures 6 à 9 on the one hand and 10 to 12 on the other hand, which present the device in two particular embodiments.

[0047] THE figures 1 à 3 already commented on in the preamble to the description are not the subject of specific developments.

[0048] As illustrated by the figures 4 à 7 , the device according to the invention, hybrid combiner-divider, comprises a primary waveguide 41 and two secondary waveguides 42 and 43.

[0049] The primary waveguide 41 has two ends: a first end configured to constitute an input-output port 48, primary input-output port, allowing the connection of the device to a signal distribution network, a beam distribution network for a multi-source antenna such as that described previously and illustrated by the figure 2 for example, and a second end forming an opening 61, located at the other end of the guide 41.

[0050] The two secondary waveguides 42 and 43 each have two opposite ends, configured to constitute two input-output ports, ports 44 and 45 for waveguide 42 and ports 46 and 47 for waveguide 43 respectively.

[0051] Each of the guides 42 and 43 also has an opening 62 or 63, arranged on one of its small lateral faces, as illustrated more particularly in the schematic view from below of the figure 5 These openings allow the cavity of the primary guide 41 to be put into communication with the cavity of the secondary guide 42 or 43 in question.

[0052] It is noted here that the expression "small lateral face" refers to the fact that the secondary guides 42 and 43 are parallelepipedal guides with rectangular section and that as such each guide has four lateral faces: two rectangular side faces ("large faces") whose length is equal to the length of the guide and whose width is equal to the large side of the rectangle defining the section of the guide; two rectangular side faces ("small faces") whose length is equal to the length of the guide and whose width is equal to the small side of the rectangle defining the section of the guide.

[0053] From a structural point of view, the device according to the invention is presented as a single-piece element having three guides secured to each other 41, 42 and 43.

[0054] In this structure, the two secondary guides 42 and 43 are arranged against each other and secured to each other by one of their large faces such that the two faces in contact form a common partition 51 separating the internal cavities of the two guides from each other.

[0055] Furthermore, the two secondary guides are arranged opposite each other in such a way that the openings 62 and 63 are placed side by side in the same plane so that they form two contiguous openings having a common edge constituted by the edge of the partition 51.

[0056] According to the invention, the primary guide 41 is arranged with respect to the block formed by the two secondary guides 42 and 43 in such a way that the opening 61 formed by its open end is positioned opposite the double opening constituted by the two contiguous openings 62 and 63 of the secondary guides 42 and 43. In this way the two cavities of the guides 42 and 43 open into the cavity of the guide 41.

[0057] Furthermore, from a structural point of view, the wall of the primary guide 41 is integral, at the level of the openings 62 and 63 of the two secondary guides 42 and 43. In this way, the device according to the invention is presented as a single-piece structure with a primary input-output port 48 and four secondary input-output ports 44-45 and 46-47.

[0058] From a dimensional point of view, the respective dimensions of the primary waveguide 41 and the secondary waveguides 42 and 43, the widths and heights defining the sections of the guides mainly, as well as the dimensions of the openings 61, 62 and 63 are defined, so that the primary waveguide 41 forms with each secondary waveguide a plane coupler E, the sum of the waves passing through each secondary guide being equal to the wave passing through the primary waveguide 41. The dividing wall 51 which separates the two cavities 61 and 62 here advantageously plays the role of a divider-combiner.

[0059] From a functional point of view, when integrated into a transmission chain, the device according to the invention, a reciprocal device, advantageously acts as a hybrid device ensuring, in two integrated stages, the distribution of an incident wave entering through the primary port 48 to the four secondary ports. It thus advantageously behaves as an integrated divider (power distributor), with one input and four outputs.

[0060] Conversely, when integrated into a reception chain, the device according to the invention acts in an equally advantageous manner, as a hybrid device ensuring, in two integrated stages, the recombination of four incident waves entering through each of the secondary input-output ports 44-45 and 46-47, into a single wave delivered by the primary input-output port 48.

[0061] THE figures 8 And 9illustrate a second embodiment which is a structural variant of the basic version of the device according to the invention described previously.

[0062] It is also known that in a plane coupler E constituted by a first waveguide having one end forming an opening opening onto the side wall of a second waveguide and forming a plane divider E, the division into two waves of the wave transmitted by the first waveguide to the second waveguide is carried out optimally to the extent that the impedance matching of the second waveguide is good. Now in general, for this purpose, a conductive element of height h is placed inside the second guide in a mid-position relative to the length L of the guide, this conductive element being connected by one of its ends to the wall of the guide.

[0063] The form of realization of the figure 8 And 9takes up this consideration and integrates in each of the secondary guides 42 and 43 a conductive partition, oriented transversely, the height h of which is determined so as to achieve this impedance adaptation and thus to promote the division of the wave transmitted by the primary guide or conversely the phase recombination of the waves received by the secondary input-output ports.

[0064] It should be noted here that the conductive partitions 52 or 53 placed respectively in the secondary waveguides 42 and 43 have a height h substantially less than the height of the guides. Their function is not to close the section of the guide in which each of them is placed. They can, moreover, be replaced by conductive elements having various shapes projecting inside the guide in question and configured to ensure good impedance matching.

[0065] THE figures 10 à 12 illustrate a second embodiment of the device according to the invention which takes up the structural and dimensional characteristics of the basic form illustrated by the figures 4 à 8 .

[0066] However, in this more elaborate embodiment, the device according to the invention additionally integrates a structure making it possible to form, upon reception, "difference" channels, which can be used in the context of deviation measurements.

[0067] This additional structure consists, as illustrated in particular by the figure 10 , in two complementary tertiary waveguides 81 and 82, rectangular, the dimensions of which are adapted to the frequency band of the electromagnetic waves intended to pass through them.

[0068] The guides 81 and 82 are placed transversely on each side of the device according to the invention at the level of the secondary guides 42 and 43. In a preferred embodiment, these tertiary guides are placed in the middle position, as illustrated by the figures 8 à 10 .

[0069] Each guide has a first end configured to constitute an output port 83 or 84, and a second end, by which it is secured to the secondary guide with which it is associated, which forms an opening 91 or 92.

[0070] As illustrated in the side sectional view of the figure 12 , section passing through the plane of the lateral face of the secondary guide 42 this opening 91 (or 92 for the guide 82) is placed opposite a similar opening made in the large face of the corresponding secondary waveguide 42 or 43 opposite the adjoining face forming the partition 51.

[0071] Each tertiary waveguide 91 or 92 is also dimensioned (length, section) to form, with the secondary waveguide 42 or 43 to which it is fixed, a plane H coupler making it possible, in reception, to produce the difference of the waves received by each of the input-output ports, 44-45 or 46-47 respectively, of the secondary waveguide to which it is attached.

[0072] This additional structure advantageously makes it possible, in reception, without altering the essential character of compactness of the device according to the invention, to form both a channel called the Sum channel for which the signals transmitted to the device by the secondary input-output ports 44-47 are combined in phase, the resulting signal being delivered via the primary input-output port 48, and two channels called Difference channels for which the signals transmitted to the device by the secondary input-output ports 44-45 on the one hand and 46-47 on the other hand are combined two by two in phase opposition, the difference signals being respectively delivered via the input-output ports 83 and 84.

[0073] We thus obtain a device constituting a compact structure forming a double magic T (or hybrid T), a structure ensuring, in a known manner, a double coupling plane E and plane H.

[0074] In this latter embodiment, the device according to the invention can thus advantageously fulfill two distinct functions: a main function of hybrid combiner-divider with a primary input-output port and four secondary input-output ports, the compact combiner-divider thus formed being able to be integrated into a beam distribution network for MFB antenna; a secondary function making it possible to form so-called "difference" channels which can be used in the context of the implementation of a so-called "RF Sensing" functionality (deviation measurement) which makes it possible, in a known manner, to measure the misalignment of the beam considered relative to the axis of the antenna through which this beam passes.

[0075] Thanks to the single-block structure of the device according to the invention, the implementation of this second functionality can be implemented without adding hardware specifically dedicated to it.

[0076] In general, the device according to the invention can be produced by various known methods, not presented here, in particular by methods for producing waveguides and hybrid couplers. It can in particular be produced by molding or machining in two half-shells and assembling the half-shells thus produced.

[0077] It should also be noted that, as illustrated by the various views presented in the attached figures, the primary waveguide can be formed by a simple straight guide or by a "twist" guide without this changing the operating principle of the device, the configuration of the primary guide being essentially linked to the arrangement of the various elements constituting the distribution network in which it is integrated.

Claims

1. A reciprocal compact E / H hybrid combiner-divider for performing the coupling or the splitting of electromagnetic waves, containing at least one main waveguide (41) and two secondary waveguides (42, 43), the main waveguide and the secondary waveguides each having a parallelepipedal structure of rectangular cross-section with two ends; wherein the main waveguide and the secondary waveguides form a one-piece structure in which: - the main waveguide has a first end configured to form an input / output port (48) and a second end defining an aperture (61), - the secondary waveguides having a same configuration and substantially identical dimensions, each secondary waveguide having two ends configured to form two input / output ports (44-45, 46-47), as well as a side aperture (62, 63) provided on one of the small faces of the waveguide, - the secondary waveguides (42, 43) are arranged one against the other and being integral with each other through one of their lateral faces, such that the two faces in contact with each other form a common side wall (51); - the secondary waveguides (42, 43) are arranged facing the main waveguide such that the side apertures (62, 63) are placed across from the aperture (61) formed by one of the ends of the main waveguide (41) and that the common wall (51) is aligned with the central axis of the aperture (61) of the main waveguide (41).

2. The E / H hybrid combiner-divider according to claim 1, characterised in that each of the secondary waveguides (42, 43) contains an internal conductive element (52, 53) placed in the cavity of the waveguide and in electrical contact with the wall of the guide, said internal conductive element being arranged inside the waveguide so as to optimise the matching of the impedance of the guide and the combination or the division of the waves travelling through the guide.

3. The E / H hybrid combiner-divider according to claim 2, characterised in that the internal conductive element (52, 53) is a pin fixed in a substantially central position on the inner face of the upper wall of the guide.

4. The E / H hybrid combiner-divider according to claim 2, characterised in that the internal conductive element (52, 53) is formed by a wall projecting into the guide, placed transversely in a substantially central position on the inner face of the upper wall of the guide, the height of said projection being substantially less than the height of the guide.

5. The E / H hybrid combiner-divider according to claim 1, characterised in that it further contains two tertiary waveguides (81, 82) placed transversely with respect to each of the secondary waveguides (41, 42) and being integral with them, each tertiary waveguide (81, 82) having a parallelepipedal structure of rectangular cross-section with two ends, a first end configured to form an input-output port (83, 84) and a second end forming an aperture (91, 92) placed across from an aperture provided in the side wall of each secondary waveguide (42, 43) opposite the common wall (51), in a substantially central position, said aperture being configured to put each secondary waveguide (42, 43) in communication with a tertiary waveguide (81, 82) placed transversely with respect thereto, so as to achieve an H-plane coupling, the combiner-divider thus having an E-H hybrid T-structure.

6. A beam distribution network for a multiple feed per beam (MFB) antenna, characterised in that it contains a first group and a second group of hybrid combiner-dividers according to any one of the preceding claims, each combiner-divider (25) of the first group acting as a combiner being connected, via its secondary ports (44-47), to the reception paths of four radiating sources and to a beam reception path via its primary port (48); each combiner-divider (27) of the second group acting as a combiner being connected, via its secondary ports (44-47), to the emission paths of four radiating sources and to a beam transmission path via its primary port (48).

7. The beam distribution network for a multiple feed per beam (MFB) antenna according to claim 6, characterised in that the combiner-dividers of the first group are combiner-dividers according to claim 5 whose ancillary output ports are connected to a deviation measurement device.

8. A beam-forming network (MFB) antenna comprising a first plurality of radiating sources combined into groups of four radiating sources and a second plurality of hybrid combiner-dividers according to any one of claims 1 to 6, characterised in that the reception paths and the transmission paths of the radiating sources belonging to one and the same group are connected, respectively, to the secondary ports (44-47) of a combiner-divider (25) whose primary port is connected to the reception path of a beam and to the secondary ports (44-47) of a combiner-divider (27) whose primary port is connected to the transmission path of the same beam.