Radiofrequency exciter with asymmetric junctions, associated system for transmitting or receiving radiofrequency waves and associated production method

Abstract

The invention relates to a junction device (30) which comprises a first and a second asymmetric waveguide junction (32, 32') that are substantially identical and arranged head-to-tail, each asymmetric junction (32, 32') comprising: - a main pipe (34, 34'); - a first axial access (36A, 36A') and a first radial access (38A, 38A'); - a second axial access (36B, 36B') and a second radial access (38B, 38B'). Each asymmetric junction (32, 32') is such that the first radial access (38A, 38A') and the second radial access (38B, 38B') are oriented respectively in a first direction and a second direction forming therebetween an angle of between 85° and 95°.

Description

[0001] DESCRIPTION

[0002] Radio frequency exciter with asymmetric junctions, radio frequency wave transmission or reception system and associated manufacturing process

[0003] The present invention relates to a radio frequency exciter of a radio frequency wave transmission or reception system, comprising a junction device, intended to connect at least one primary port to at least one secondary receiving port and to at least one secondary transmitting port.

[0004] The invention applies in particular to the field of space telecommunications for antennas located on board spacecraft or on the ground, in particular for DTH (Direct To Home), HTS (High Throughput Satellite) or VHTS (Very High Throughput Satellite) applications.

[0005] Known radio frequency exciters classically include devices that allow the separation of different polarizations as well as the separation of transmit and receive frequency bands.

[0006] State-of-the-art radio frequency exciters do not allow for the following simultaneously:

[0007] - to be compact with regard to the radial footprint of the exciter;

[0008] - to cover large frequency bands in transmission and / or reception;

[0009] - to present optimized radiation diagrams; and

[0010] - to avoid degradation of the received or transmitted signal due in particular to phase shifts induced by the junction device.

[0011] One aim of the invention is therefore to propose a radio frequency exciter that improves the radial compactness of the exciter, covers wider frequency bands, optimizes the corresponding radiation patterns and improves the quality of the received or transmitted signal.

[0012] To this end, the invention relates to a radio frequency exciter of the aforementioned type, in which: the junction device comprises a first and a second asymmetric waveguide junction, substantially identical, each asymmetric waveguide junction comprising: a main conduit extending substantially parallel to a longitudinal axis; at a first axial end of the main conduit, a first axial access and a first radial access; at a second axial end of the main conduit, opposite the first axial end of the main conduit, a second axial access and a second radial access;each asymmetric junction being such that: the first radial access and the second radial access are oriented, in planes substantially perpendicular to the longitudinal axis, respectively along a first direction and a second direction forming between them an angle between 85° and 95°, in particular substantially equal to 90°; and the two asymmetric junctions are arranged so that: the first radial access of the first asymmetric junction is connected to the second radial access of the second asymmetric junction and coplanar with said second radial access in the same first plane perpendicular to the longitudinal axis; the second radial access of the first asymmetric junction is connected to the first radial access of the second asymmetric junction and coplanar with said first radial access in the same second plane perpendicular to the longitudinal axis, said first and second planes being separated by a non-zero distance along the longitudinal axis.

[0013] The invention is particularly suited to circularly biased signals, but can nevertheless be used for linearly biased signals.

[0014] According to other advantageous aspects of the invention, the radio frequency exciter comprises one or more of the following features, taken individually or in any technically possible combination:

[0015] - for each asymmetric junction, the first radial access and the second radial access respectively comprise a first and a second slot, each of said slots being made in a peripheral wall of the corresponding main conduit, the first and second slots being respectively intended for the passage of horizontally and vertically polarized linear waves;

[0016] - the junction device further comprises a first and a second emission filter, preferably identical, centered on the emission frequency band such that: the first emission filter connects the first radial access of the first asymmetric junction and the second radial access of the second asymmetric junction; and the second emission filter connects the second radial access of the first asymmetric junction and the first radial access of the second asymmetric junction;

[0017] - the second axial access of the second asymmetric junction is closed by a short circuit or connected to an absorbing load of the radio frequency exciter;

[0018] - the radio frequency exciter further comprises: at least one primary port intended to be connected to a radiating antenna and to carry waves of frequencies within a reception frequency band or within a transmission frequency band; at least one secondary reception port intended to carry waves of frequencies within the reception frequency band and to exclude waves of frequencies within the transmission frequency band; at least one secondary transmission port intended to carry waves of frequencies within the transmission frequency band and to exclude waves of frequencies within the reception frequency band; the two asymmetric junctions being arranged such that: the first axial access of the first asymmetric junction is connected to at least one primary port;the second axial access of the first asymmetric junction is connected to one of at least one secondary receive port and at least one secondary transmit port; and the first axial access of the second asymmetric junction is connected to the other of at least one secondary receive port and at least one secondary transmit port;

[0019] - the radio frequency exciter includes a first secondary receiving port, a second secondary receiving port, a first secondary transmitting port and a second secondary transmitting port;

[0020] - the first secondary receiving port is intended to carry right-hand circularly polarized waves, the second secondary receiving port is intended to carry left-hand circularly polarized waves, the radio frequency exciter further comprising a septum polarizer connecting the first secondary receiving port and the second secondary receiving port to the junction device; or the first secondary receiving port is intended to carry horizontally linearly polarized waves, the second secondary receiving port is intended to carry vertically linearly polarized waves, the radio frequency exciter further comprising a polarization diplexer connecting the first secondary receiving port and the second secondary receiving port to the junction device;

[0021] - the first secondary transmitting port is intended to carry right-hand circularly polarized waves, the second secondary transmitting port is intended to carry left-hand circularly polarized waves, the radio frequency exciter further comprising a septum polarizer connecting the first secondary transmitting port and the second secondary transmitting port to the junction device; or the first secondary transmitting port is intended to carry horizontally linearly polarized waves, the second secondary transmitting port is intended to carry vertically linearly polarized waves, the radio frequency exciter further comprising a polarization diplexer connecting the first secondary transmitting port and the second secondary transmitting port to the junction device;

[0022] - the first and second asymmetric junctions and / or the septum polarizer(s) and / or the polarization diplexer(s) are formed in one piece.

[0023] The invention further relates to a radio frequency wave transmission or reception system comprising: a radiating antenna, for example a radiating horn; and a radio frequency exciter as described above, at least one primary port of the radio frequency exciter being connected to the radiating antenna.

[0024] The invention further relates to a method for manufacturing a radio frequency exciter as described above, comprising: an additive manufacturing step including the additive manufacturing of the junction device; and a step of arranging the junction device such that: the first axial access of the first asymmetric junction is connected to at least one primary port; the second axial access of the first asymmetric junction is connected to one of at least one secondary receiving port and at least one secondary transmitting port; the first axial access of the second asymmetric junction is connected to the other of at least one secondary receiving port and at least one secondary transmitting port; the first radial access of the first asymmetric junction is connected to the second radial access of the second asymmetric junction;and the second radial access of the first asymmetric junction is connected to the first radial access of the second asymmetric junction.

[0025] The invention will become clearer upon reading the following description, given solely by way of non-limiting example, and made with reference to the drawings in which:

[0026] - Figure 1 is a simplified schematic illustration of a first embodiment of a radio frequency wave emission or reception system according to the invention;

[0027] - Figure 2 is a partial, perspective view of an asymmetric junction of the radio frequency wave emission or reception system of Figure 1;

[0028] - Figure 3 is a partial simplified schematic illustration of the junction device of the radio frequency wave transmission or reception system of Figure 1;

[0029] - Figure 4 is a partial, perspective view of a radio frequency exciter of the radio frequency wave emission or reception system of Figure 1;

[0030] - Figure 5 is a flowchart illustrating a manufacturing process for a radio frequency exciter of the radio frequency wave emission or reception system of Figure 1, according to the invention;

[0031] - Figure 6 is a simplified schematic illustration of a variant of the radio frequency wave emission or reception system of Figure 1;

[0032] - Figure 7 is a simplified schematic illustration of a second embodiment of a radio frequency wave transmission or reception system according to the invention; and

[0033] - Figure 8 schematically shows partial, sectional views of Figure 7. With reference to Figures 1 to 4, a first embodiment of a radio frequency wave emission or reception system 10 according to the invention is described.

[0034] The system 10 includes a radiating antenna 12 and a radio frequency exciter 16.

[0035] For example, radiating antenna 12 is a radiating horn.

[0036] The radio frequency exciter 16 includes at least one primary port 20, at least one secondary receiving port 22, at least one secondary transmitting port 24 and a junction device 30.

[0037] According to the example illustrated in Figures 1 to 4, the radio frequency exciter 16 comprises a first secondary receiving port 22A, a second secondary receiving port 22B, a first secondary transmitting port 24A and a second secondary transmitting port 24B. For example, the radio frequency exciter 16 comprises a single primary port 20.

[0038] Advantageously, the radio frequency exciter 16 further includes a short circuit 60.

[0039] Advantageously, in the first embodiment, the radio frequency exciter 16 further includes a septum polarizer 66 connecting the first secondary receiving port 22A and the second secondary receiving port 22B to the junction device 30, in particular in the example of Figure 1 to a second axial access 36B of a first asymmetric junction 32 of the junction device 30.

[0040] Advantageously, in the first embodiment, the radio frequency exciter 16 further includes a septum polarizer 68 connecting the first secondary transmitting port 24A and the second secondary transmitting port 24B to the junction device 30, in particular in the example of Figure 1 to a first axial access 36A' of a second asymmetric junction 32' of the junction device 30.

[0041] Advantageously, the radio frequency exciter 16 further includes a transition module 56 connecting the junction device 30, in particular in the example of Figure 1 a first axial access 36A of the first asymmetric junction 32, and at least one primary port 20. In particular, the radio frequency exciter 16 includes a transition module 56 when the cross sections of the waveguides forming the junction device 30 and the cross section of the radiating antenna 12 are of different geometric shapes.

[0042] The transition module 56 is configured to be connected to the radiating antenna 12, specifically to a radiating horn. The cross-section of the transition module 56 can be circular or square depending on the type of horn used, and in particular, the geometric shape of the horn's cross-section. Specifically, the transition module 56 acts as an impedance matching module.

[0043] At least one primary port 20 is connected to the radiating antenna 12 and is intended to carry waves of frequencies within a receive frequency band Rx or within a transmit frequency band Tx.

[0044] More specifically, at least one primary port 20 is capable of carrying circularly polarized Tx / Rx frequency waves. Theoretically, a circularly polarized signal is a decomposition of two linear signals phase-shifted by 90°. In the following description, circularly polarized Tx signals are considered to comprise horizontal linear signals Tx(H) and vertical linear signals Tx(V), phase-shifted by 90°. Similarly, circularly polarized Rx signals are considered to comprise horizontal linear signals Rx(H) and vertical linear signals Rx(V), phase-shifted by 90°.

[0045] At least one secondary receive port 22, in particular the first secondary receive port 22A and the second secondary receive port 22B, is intended to carry waves of frequencies within the receive frequency band Rx and to exclude waves of frequencies within the transmit frequency band Tx.

[0046] For example, in the first embodiment, the first secondary receiving port 22A is intended to carry right-hand circularly polarized waves and the second secondary receiving port 22B is intended to carry left-hand circularly polarized waves.

[0047] At least one secondary transmit port 24, in particular the first secondary transmit port 24A and the second secondary transmit port 24B, is intended to carry waves of frequencies within the transmit frequency band Tx and to exclude waves of frequencies within the receive frequency band Rx.

[0048] For example, in the first embodiment, the first secondary transmit port 24A is intended to carry right-hand circularly polarized waves and the second secondary transmit port 24B is intended to carry left-hand circularly polarized waves.

[0049] Figures 7 and 8 show a radio frequency wave transmission or reception system 210 according to a second embodiment of the invention. System 210 is analogous to system 10 described previously, and the above description of system 10 also applies to system 210.

[0050] In particular, the system 210 in Figures 7 and 8 includes a radio frequency exciter 216, said exciter comprising, among other things, a junction device 230. This junction device 230 is suitable for replacing the junction device 30 in the radio frequency exciter 16 and the system 10 described above. Only the junction device 230 is visible in Figure 7 for the system 210 and the radio frequency exciter 216.

[0051] The 30 and 230 junction devices will be described simultaneously below, with common elements designated by the same reference numbers.

[0052] The junction device 30, 230 connects at least one primary port 20 to at least one secondary receiving port 22 and to at least one secondary transmitting port 24.

[0053] The junction device 30 comprises the first asymmetric waveguide junction 32 and the second asymmetric waveguide junction 32'. Similarly, the junction device 230 comprises a first asymmetric waveguide junction 232 and a second asymmetric waveguide junction 232'.

[0054] Advantageously, the junction device 30, 230 further comprises a first 48, 248 and a second 50, 250 transmission filters. These transmission filters 48, 248, 50, 250 are centered on the transmission frequency band Tx and specifically exclude frequencies from the reception frequency band Rx.

[0055] The first and second asymmetric waveguide junctions 32, 32' of the junction device 30 are substantially identical. Similarly, the first and second asymmetric waveguide junctions 232, 232' of the junction device 230 are substantially identical.

[0056] In the present description, in comparison to the elements of the first asymmetric junction 32, 232, the numerical references of the elements of the second asymmetric junction 32', 232' present the prime typographic sign.

[0057] The first 32, 232 and second 32', 232' asymmetric junctions each include:

[0058] - a main conduit 34, 34', 234, 234' extending substantially parallel to a longitudinal axis X1, X2;

[0059] - at a first axial end 34A, 34A' of the main conduit 34, 34', 234, 234', a first axial access 36A, 36A', 236A, 236A' and a first radial access 38A, 38A', 238A, 238A';

[0060] - to a second axial end 34B, 34B' opposite the first axial end 34A, 34A', a second axial access 36B, 36B', 236B, 236B' and a second radial access 38B, 38B', 238B, 238B'.

[0061] Each asymmetrical junction 32, 32', 232, 232' is such that the first radial access 38A, 38A', 238A, 238A' and the second radial access 38B, 38B', 238B, 238B' are oriented, in planes substantially perpendicular to the longitudinal axis X1, X2, respectively along a first direction D1 and a second direction D2 (Figure 2, Figure 8) forming between them an angle α between 85° and 95°, in particular substantially equal to 90°. In the embodiments shown, the angle α is equal to 90°.

[0062] Advantageously, the longitudinal axis X1 of the main pipe 34, 234 of the first asymmetric junction 32, 232 and the longitudinal axis X2 of the main pipe 34', 234' of the second asymmetric junction 32', 232' are parallel.

[0063] Advantageously, the main conduit 34, 34', 234, 234' of each asymmetric junction 32, 32', 232, 232' comprises a first portion 36, 36', 236, 236' at the first axial end 34A, 34A' and a second portion 38, 38', 238, 238' at the second axial end 34B, 34B'. In particular, the first portion 36, 36', 236, 236' of the main conduit of each asymmetric junction is connected to the first axial access 36A, 36A', 236A, 236A' and to the first radial access 38A, 38A', 238A, 238A'; and the second portion 38, 38', 238, 238' of the main conduit of each asymmetric junction is connected to the second axial access 36B, 36B', 236B, 236B' and to the second radial access 38B, 38B', 238B, 238B'.

[0064] The first asymmetric junction 32, 232 will be described more precisely, considering that the second asymmetric junction 32', 232' is substantially identical to it.

[0065] The first portion 36, 236 of the first asymmetric junction 32, 232 comprises a first peripheral wall 37, 237, extending along the longitudinal axis X1. The first peripheral wall 37, 237 defines a first cavity 39, 239.

[0066] The second portion 38, 238 includes a second peripheral wall 41, 241, extending along the longitudinal axis X1. The second peripheral wall 41, 241 defines a second cavity 43, 243.

[0067] The first 39, 239 and second 41, 241 cavities are continuous along the longitudinal axis X1.

[0068] Advantageously, the first radial access 38A, 238A of the first asymmetric junction 32, 232 is centered on a first plane 47, 247; and the second radial access 38B, 238B of the first asymmetric junction 32, 232 is centered on a second plane 49, 249. These first 47, 247 and second 49, 249 planes are perpendicular to the longitudinal axis X1. A non-zero distance 51, 251 separates these first 47, 247 and second 49, 249 planes along said longitudinal axis X1.

[0069] In the embodiments shown, the main conduit 34, 34', 234, 234' of each asymmetrical junction 32, 32', 232, 232' has a rectangular or square cross-section perpendicular to the longitudinal axis X1, X2. In an alternative not shown, the main conduit of each asymmetrical junction has a circular or elliptical cross-section. Advantageously, the cross-section of the conduit 34, 34', 234, 234' of each asymmetrical junction 32, 32', 232, 232' has a decreasing area from the first end 34A, 34A' to the second end 34B, 34B', as will be detailed below.

[0070] In the junction device 30, 230, the first 32, 232 and second 32', 232' asymmetrical junctions are arranged such that:

[0071] - the first radial access 38A, 238A of the first asymmetric junction 32, 232 is connected to the second radial access 38B', 238B' of the second asymmetric junction 32', 232';

[0072] - the second radial access 38B, 238B of the first asymmetric junction 32, 232 is connected to the first radial access 38A', 238A' of the second asymmetric junction 32'.

[0073] Advantageously, the first 32, 232 and second 32', 232' asymmetric junctions are arranged head-to-tail, that is, the first axial access 36A, 236A of the first asymmetric junction 32, 232 is closer to the second axial access 36B', 236B' of the second asymmetric junction 32', 232' than to the first axial access 36A', 236A' of said second asymmetric junction.

[0074] Advantageously, the junction device 30, 230 is configured so that the first radial access 38A', 238A' of the second asymmetric junction 32', 232' is centered on the second plane 49, 249; and the second radial access 38B', 238B' of the second asymmetric junction 32', 232' is centered on the first plane 47, 247, as seen in Figures 4 and 7.

[0075] We consider an orthonormal basis (X, Y, Z) associated with the junction device 30, 230. The direction X is parallel to the longitudinal axes X1 and X2; the direction Y is parallel to the direction D1 of the first radial accesses 38A, 38A', 238A, 238A'; and the direction Z is parallel to the direction D2 of the second radial accesses 38B, 38B', 238B, 238B'.

[0076] Positioning the first radial access of the first asymmetric junction and the second radial access of the second asymmetric junction in the same first plane 47, 247, and positioning the second radial access of the first asymmetric junction and the first radial access of the second asymmetric junction in the same second plane 49, 249, cancels the phase differences between the first 32, 232 and the second 32', 232' asymmetric junctions. Such an isophase architecture is therefore compatible with circularly biased signals.

[0077] Advantageously, as can be seen in Figure 1, the first 32, 232 and second 232, 232' asymmetric junctions are further arranged such that:

[0078] - the first axial access 36A, 236A of the first asymmetric junction 32, 232 is connected to at least one primary port 20; - the second axial access 36B, 236B of the first asymmetric junction 32, 232 is connected to one of at least one secondary receiving port 22 and at least one secondary transmitting port 24; and

[0079] - the first axial access 36A', 236A' of the second asymmetric junction 32', 232' is connected to the other among at least one secondary receiving port 22 and at least one secondary transmitting port 24.

[0080] On the one hand, the presence of radial accesses of each asymmetric junction and in particular their orientation relative to each other allows the radio frequency exciter to reduce its radial footprint, to cover wider frequency bands in transmission and / or reception and to improve the radiation pattern in particular by reducing the risk of generating harmonics of higher order than that of the corresponding fundamental mode.On the other hand, the arrangement of the two identical head-to-tail asymmetric junctions makes it possible to eliminate the phase shift between the waves, in particular the waves in the emission frequency band in the vertical and horizontal planes, which circulate from one asymmetric junction to the other respectively between the first radial access of the first asymmetric junction and the second radial access of the second asymmetric junction and between the second radial access of the first asymmetric junction and the first radial access of the second asymmetric junction.

[0081] The radiofrequency exciter 16 and the junction device 30 of figures 1 to 4 will now be described more specifically.

[0082] In the radiofrequency exciter 16, the two asymmetric junctions 32, 32' of the junction device 30 are arranged such that:

[0083] - the second axial access 36B of the first asymmetric junction 32 is connected to at least one secondary receive port 22, in particular via the septum polarizer 66; and

[0084] - the first axial access 36A' of the second asymmetric junction 32' is connected to at least one secondary transmit port 24, in particular via the septum polarizer 68.

[0085] As shown in Figure 2, the first radial access 38A and the second radial access 38B of the first asymmetric junction 32 each have a first 40 and a second 53 slot 40, respectively, formed in the first 37 and the second 41 peripheral wall of the main conduit 34. The first 40 and second 53 slots are intended for the passage of linearly polarized waves, horizontal and vertical respectively. The second asymmetric junction 32' has a similar configuration.

[0086] In particular, each slot 40, 53 extends parallel to the longitudinal axis X1, X2 of the corresponding conduit 34, 34' and orthoradially or transversely with respect to the longitudinal axis X1, X2. Each slot 40, 53 has a length measured along the longitudinal axis X1, X2 and a width measured orthoradially or transversely with respect to the longitudinal axis X1, X2, the length of the slot 40, 53 being for example greater than the width of the slot 40, 53.

[0087] As stated above, the slits 40, 53 are oriented relative to each other with the angle α such that one of the slits 40, 53 permits the passage of horizontally polarized linear waves and the other of the slits 40, 53 permits the passage of vertically polarized linear waves.

[0088] In the embodiment shown in Figures 2 and 4, the main conduit 34, 34' of each asymmetric junction 32, 32' comprises an asymmetric polarization diplexer. In particular, each asymmetric polarization diplexer is formed by the geometry of the walls of the first 36, 36' and second 38, 38' portions of the corresponding main conduit 34, 34'.

[0089] In particular, as can be seen in Figures 2 and 4, the first wall 37 of the main pipe 34 of the first asymmetric junction 32 has two opposing first flanks 55, parallel to the direction D2 / Z. A distance along the direction D1 / Y between said first flanks 55 is variable along the longitudinal axis X1.

[0090] Furthermore, the second wall 41 of said main pipe 34 has two opposing second flanks 57, parallel to the direction D1 / Y. A distance along the direction D2 / Z between said second flanks 57 is variable along the longitudinal axis X1.

[0091] More specifically, the first flanks 55 approach each other and the second flanks 57 approach each other between the first 34A and the second 34B axial ends of the main pipe 34. The cross-section of the main pipe 34 is therefore decreasing between the first 34A and second 34B axial ends.

[0092] The second asymmetric junction 32' has a similar configuration, as seen in Figure 4.

[0093] These specific shapes allow the horizontal and vertical signals in linear polarization to be separated by creating a short-circuit plane through the reduction of the waveguide width along direction D1 in the first section 36 of the main conduit 34, and a short-circuit plane through the reduction of the waveguide width along direction D2 in the second section 38 of said main conduit. This allows the signals to be coupled over a wide band at the slots.

[0094] In the example in Figure 4, the radial accesses 38A, 38A', 38B, 38B' of the asymmetric junctions 32 are formed by portions of waveguide 42.

[0095] In particular, the first radial access 38A of the first asymmetric junction 32 and the second radial access 38B' of the second asymmetric junction 32' are formed by a portion of waveguide 42 extending along an L-shaped path from the conduit 34 of the first asymmetric junction 32 to the conduit 34' of the second asymmetric junction 32'.

[0096] Alternatively, the first radial access 38A of the first asymmetric junction 32 and the second radial access 38B' of the second asymmetric junction 32' are formed by a portion of waveguide 42 extending along a curvilinear path from the conduit 34 of the first asymmetric junction 32 to the conduit 34' of the second asymmetric junction 32'.

[0097] In particular, the second radial access 38B of the first asymmetric junction 32 and the first radial access 38A' of the second asymmetric junction 32' are formed by a portion of waveguide 42 extending along an L-shaped path from the conduit 34 of the first asymmetric junction 32 to the conduit 34' of the second asymmetric junction 32'.

[0098] Alternatively, the second radial access 38B of the first asymmetric junction 32 and the first radial access 38A' of the second asymmetric junction 32' are formed by a portion of waveguide 42 extending along a curvilinear path from the conduit 34 of the first asymmetric junction 32 to the conduit 34' of the second asymmetric junction 32'.

[0099] For example, as illustrated in Figures 1, 3 and 4, the second axial access 36B' of the second asymmetric junction 32' is closed by short circuit 60 or connected to an absorbing load of the radio frequency exciter 16.

[0100] Advantageously, a first emission filter 48 connects the first radial access 38A of the first asymmetric junction 32 and the second radial access 38B' of the second asymmetric junction 32'.

[0101] Even more advantageously, a second emission filter 50, notably identical to the first emission filter 48, connects the second radial access 38B of the first asymmetric junction 32 and the first radial access 38A' of the second asymmetric junction 32'.

[0102] For example, each of the first and second emission filters 48, 50 is formed by an L-shaped or curved waveguide. In particular, when the waveguide is L-shaped, the angle between the two arms of the L is between 45° and 135°, preferably approximately equal to 90°.

[0103] Advantageously, the waveguides forming the first and second emission filters 48, 50 have an elliptical, rectangular, triangular, pentagonal, or hexagonal cross-section. Alternatively, the waveguides forming the first and second emission filters 48, 50 have a polygonal cross-section with more than six vertices. Those skilled in the art will be able to select the most suitable cross-sectional shape based on the exciter's size constraints, manufacturing limitations, and filtering specifications.

[0104] The radiofrequency exciter 216 and the junction device 230 of figures 7 and 8 will now be described more specifically.

[0105] The first portion 236 of the main conduit 234 of the first asymmetric junction 232 comprises a first peripheral wall 237 of constant cross-section along the longitudinal axis X1. In the embodiment shown, this cross-section has a square shape with sides of length a, extending in the Y and Z directions. In an alternative not shown, this cross-section is circular with radius a. The first cavity 239 thus has a constant cross-section along the X direction.

[0106] The second portion 238 of the main conduit 234 comprises a second peripheral wall 241 with a constant cross-section along the longitudinal axis X1. In the embodiment shown, this cross-section has a rectangular shape with first sides 61, of length a, extending along the direction D2 / Z; and second sides 63, of length b, extending along the direction D1 / Y. The length b is strictly less than the length a. The second cavity 243 thus has a constant cross-section along the X direction. In an alternative not shown, this cross-section is elliptical in shape.

[0107] Preferably, in a manner analogous to the first embodiment of figures 2 and 4, the first 238A and second 238B radial accesses are materialized respectively by a first 240 and a second 253 slots, extending along X and made respectively in the first 237 and in the second 241 peripheral walls.

[0108] The second asymmetric junction 232' has a configuration similar to that described above for the first asymmetric junction 232.

[0109] In the embodiment shown in Figure 7, the junction device 230 further comprises a first 265 and a second 265' outlet cavities. These outlet cavities 265, 265' extend respectively the first 232 and the second 232' asymmetric junctions at the level of the second axial access 236B, 236B'.

[0110] Each of the said outlet cavities 265, 265' has a constant cross-section along X, in particular a square shape with sides of length c. The length c is strictly less than the lengths a and b. The outlet cavity 265, 265' extends over a non-zero distance, along X, from the second portion 238, 238' of the main conduit 234, 234' of the corresponding asymmetric junction.

[0111] In the junction device 230, the first cavity 239 of the first asymmetric junction 232 is designed to transmit the horizontal Tx(H) signals, as well as the horizontal and vertical Rx(H+V) signals, to the second cavity 241; and the first radial access 238A, in the first plane 247, allows coupling of the vertical Tx(V) signal. The first transmit filter 248 acts as a short circuit for the vertical Rx(V) signal.

[0112] Next, the second cavity 241 is designed to transmit the horizontal and vertical Rx(H+V) signals to the output cavity 265; and the second radial access 238B, in the second plane 249, allows coupling of the horizontal Tx(H) signal. The second transmitting filter 250 acts as a short circuit for the horizontal Rx(H) signal. The rectangular section axb of the second portion 238 acts as a waveguide under the cutoff and as a short circuit for the vertical Tx(V) signal.

[0113] Next, the output cavity 265 is intended to transmit the horizontal and vertical Rx(H+V) signals to the secondary receiving port 22. The rectangular cxc section of the output cavity 265 acts as a guide under the cut and short circuit for the horizontal Tx(H) signal.

[0114] Preferably, in the radio frequency exciter 216, the output cavity 265' of the second asymmetric junction 232' is closed by a short circuit analogous to the short circuit 60 previously described, or connected to an absorbing load of the radio frequency exciter 216. Alternatively, the junction device 230 does not have a second output cavity 265' and the second axial access 236B' of the second asymmetric junction 232' is closed by short circuit or connected to an absorbing load of the radio frequency exciter 216.

[0115] Similar to the junction device 30, the emission filters 248, 250 of the junction device 230 can be formed by L-shaped or curved waveguides.

[0116] Advantageously, the junction device 30, 230 described above is formed in one piece.

[0117] For example, as illustrated in Figure 4, the first and second asymmetric junctions 32, 32' and / or, where applicable, the septum polarizers 66, 68 and / or, where applicable, the transition module 56 and / or, where applicable, the waveguide portions 42 of the radial access ports 38A, 38A', 38B, 38B' are formed in one piece. Alternatively, the first and second asymmetric junctions 32, 32' and / or, where applicable, the septum polarizers 66, 68 and / or, where applicable, the transition module 56 and / or, where applicable, the waveguide portions 42 of the radial access ports 38A, 38A', 38B, 38B' are formed in several pieces.

[0118] With reference to Figure 5, a manufacturing process 100 of the radio frequency exciter 16 is described. An analogous process can be used for the radio frequency exciter 216.

[0119] The manufacturing process 100 includes an additive manufacturing step 110. The additive manufacturing step 110 includes the additive manufacturing of the junction device 30. Advantageously, the additive manufacturing step 110 further includes, where appropriate, the additive manufacturing of the septum polarizers 66, 68 and, where appropriate, the transition module 56, in particular so that the junction device 30, the septum polarizers 66, 68 and the transition module 56 are in a single piece.

[0120] The additive manufacturing of the junction device 30 includes in particular the additive manufacturing of the first and second asymmetric junctions 32, 32', and where applicable the waveguide portions 42 of the radial accesses 38A, 38A', 38B, 38B'.

[0121] Advantageously, with reference to Figure 4, additive manufacturing is carried out along an additive manufacturing direction DFA (Figure 4) substantially parallel to the longitudinal axis X1, X2, in a direction going from the first axial access 36A' of the second asymmetric junction 32' to the first axial access 36A of the first asymmetric junction 32.

[0122] Furthermore, the additive manufacturing of the junction device 30, and in particular of the waveguide portions 42 of the radial access ports 38A, 38A', 38B, 38B', is such that:

[0123] - the first radial access 38A of the first asymmetric junction 32 is connected to the second radial access 38B' of the second asymmetric junction 32';

[0124] - the second radial access 38B of the first asymmetric junction 32 is connected to the first radial access 38A' of the second asymmetric junction 32'.

[0125] The manufacturing process 100 further includes a step 120 of arranging the joining device 30 such that:

[0126] - the first axial access 36A of the first asymmetric junction 32 is connected to at least one primary port 20;

[0127] - the second axial access 36B of the first asymmetric junction 32 is connected to one of at least one secondary receiving port 22 and at least one secondary transmitting port 24;

[0128] - the first axial access 36A' of the second asymmetric junction 32' is connected to the other among at least one secondary receiving port 22 and at least one secondary transmitting port 24.

[0129] A first variant embodiment of the transmission or reception system 10 described above is illustrated in Figure 6. This variant embodiment can be adapted to the transmission or reception system 210 described above.

[0130] In this first variant of the implementation:

[0131] - the first secondary receiving port 22A is intended to carry right-hand circularly polarized waves and the second secondary receiving port 22B is intended to carry left-hand circularly polarized waves; and - the first secondary transmitting port 24A is intended to carry horizontally linearly polarized waves and the second secondary transmitting port 24B is intended to carry vertically linearly polarized waves.

[0132] In this first embodiment, the radio frequency exciter 16 comprises:

[0133] - a septum polarizer 72 connecting the first secondary receive port 22A and the second secondary receive port 22B to the junction device 30, in particular to the second axial access 36B of the first asymmetric junction 32; and

[0134] - a polarization diplexer 74 (or "orthomode transducer" in English) connecting the first secondary transmit port 24A and the second secondary transmit port 24B to the junction device 30, in particular to the first axial access 36A' of the second asymmetric junction 32'.

[0135] A third embodiment is illustrated in Figure 7.

[0136] A second variant of the system 10, 210, not shown, is as follows:

[0137] - the first secondary receiving port 22A is intended to carry horizontally polarized waves and the second secondary receiving port 22B is intended to carry vertically polarized waves; and

[0138] - the first secondary transmit port 24A is intended to carry right-hand circularly polarized waves and the second secondary transmit port 24B is intended to carry left-hand circularly polarized waves.

[0139] In this second variant, the radio frequency exciter 16 comprises:

[0140] - a polarization diplexer 74 connecting the first secondary receive port 22A and the second secondary receive port 22B to the junction device 30, in particular to the second axial access 36B of the first asymmetric junction 32; and

[0141] - a septum polarizer 72 connecting the first secondary transmit port 24A and the second secondary transmit port 24B to the junction device 30, in particular to the first axial access 36A' of the second asymmetric junction 32'.

[0142] A third variant of the system 10, 210, not shown, is as follows:

[0143] - the first secondary receiving port 22A is intended to carry horizontally polarized waves and the second secondary receiving port 22B is intended to carry vertically polarized waves; and

[0144] - The first secondary transmission port 24A is intended for carrying horizontally polarized waves, and the second secondary transmission port 24B is intended for carrying vertically polarized waves. In this third variant, the radio frequency exciter 16 comprises:

[0145] - a first polarization diplexer 74 connecting the first secondary receive port 22A and the second secondary receive port 22B to the junction device 30, in particular to the second axial access 36B of the first asymmetric junction 32; and

[0146] - a second polarization diplexer 74 connecting the first secondary transmit port 24A and the second secondary transmit port 24B to the junction device 30, in particular to the first axial access 36A' of the second asymmetric junction 32'.

[0147] In system 10 and each of the variants described above, the first and second asymmetric junctions 32, 32' and / or where applicable the septum polarizer(s) 66, 68, 720 and / or where applicable the polarization diplexer(s) 74 and / or where applicable the transition module 56 and / or where applicable the waveguide portions 42 of the radial accesses 38A, 38A', 38B, 38B' are preferably formed in one piece. Alternatively, the first and second asymmetric junctions 32, 32' and / or where applicable the septum polarizer(s) 66, 68, 72 and / or where applicable the polarization diplexer(s) 74 and / or where applicable the transition module 56 and / or where applicable the waveguide portions 42 of the radial accesses 38A, 38A', 38B, 38B' are formed in several pieces.

[0148] In system 10 and each of the variants described above, the manufacturing process 100 is such that the additive manufacturing step 110 includes the additive manufacturing of the junction device 30, where applicable the transition module 56 and in particular further where applicable the septum polarizer(s) 66, 68, 72 and / or the polarization diplexer(s) 74.

[0149] Thanks to the invention:

[0150] - the radial bulk of the radiofrequency exciter 16, 216 is reduced, in particular by the orientation of the radial accesses 38A, 38A', 38B, 38B' of each asymmetric junction 32, 32' relative to each other;

[0151] - wider frequency bands are covered in transmission and / or reception;

[0152] - the radiation pattern of the 10,210 system is improved, notably by reducing the risk of generating harmonics of a higher order than that of the corresponding fundamental mode; and

[0153] - the risks of phase shift between waves circulating from one asymmetric junction to the other are reduced, in particular by the arrangement of the two asymmetric junctions 32, 32', 232, 232' identical to each other, which form an isophase architecture compatible with circularly biased signals.

Claims

DEMANDS 1. Radio frequency exciter (16, 216) of a radio frequency wave transmission or reception system (10, 210), comprising a junction device (30, 230) intended to connect at least one primary port (20) to at least one secondary receiving port (22) and to at least one secondary transmitting port (24); characterized in that: - the junction device (30, 230) comprises a first (32, 232) and a second (32', 232') asymmetric waveguide junctions, substantially identical, each asymmetric waveguide junction comprising: - a main conduit (34, 34') extending substantially parallel to a longitudinal axis (X1, X2); - at a first axial end (34A, 34A') of the main conduit (34, 34'), a first axial access (36A, 36A') and a first radial access (38A, 38A', 238A, 238A'); - at a second axial end (34B, 34B') of the main conduit (34, 34') opposite the first axial end (34A, 34A') of the main conduit (34, 34'), a second axial access (36B, 36B') and a second radial access (38B, 38B', 238B, 238B'); each asymmetrical junction (32, 32', 232, 232') being such that: - the first radial access (38A, 38A', 238A, 238A') and the second radial access (38B, 38B', 238B, 238B') are oriented, in planes (47, 49, 247, 249) substantially perpendicular to the longitudinal axis (X1, X2), respectively along a first direction (D1) and a second direction (D2) forming between them an angle (a) between 85° and 95°, in particular substantially equal to 90°; and - the two asymmetrical junctions (32, 32', 232, 232') are arranged such that: - the first radial access (38A) of the first asymmetric junction (32) is connected to the second radial access (38B') of the second asymmetric junction (32') and coplanar with said second radial access in the same first plane (47, 247) perpendicular to the longitudinal axis; - the second radial access (38B) of the first asymmetric junction (32) is connected to the first radial access (38A') of the second asymmetric junction (32') and coplanar with said first radial access in the same second plane (49, 249) perpendicular to the longitudinal axis, said first and second planes being separated by a non-zero distance (41, 241) along the longitudinal axis.

2. Radio frequency exciter (16, 216) according to claim 1, wherein for each asymmetric junction (32, 32'), the first radial access (38A, 38A', 238A, 238A') and the second radial access (38B, 38B', 238B, 238B') respectively comprise a first (40, 240) and a second (53, 253) slot, each of said slots being made in a peripheral wall (37, 237, 39, 239) of the corresponding main conduit, the first and second slots being respectively intended for the passage of horizontally and vertically polarized linear waves.

3. Radio frequency exciter (16, 216) according to claim 1 or 2, wherein the junction device (30, 230) further comprises a first (48, 248) and a second (50, 250) emission filters, preferably identical, centered on the emission frequency band (Tx) such that: - the first emission filter (48, 248) connects the first radial access (38A) of the first asymmetric junction (32) and the second radial access (38B') of the second asymmetric junction (32'); and - the second emission filter (50, 250) connects the second radial access (38B) of the first asymmetric junction (32) and the first radial access (38A') of the second asymmetric junction (32').

4. Radio frequency exciter (16, 216) according to any one of the preceding claims, wherein the second axial access (36B') of the second asymmetric junction (32') is closed by a short circuit (60) or connected to an absorbing load of the radio frequency exciter (16).

5. Radio frequency exciter (16) according to any one of the preceding claims, further comprising: - at least one primary port (20) intended to be connected to a radiating antenna (12) and to carry waves of frequencies included in a reception frequency band (Rx) or in a transmission frequency band (Tx); - at least one secondary receiving port (22) intended to carry waves of frequencies included in the receiving frequency band (Rx) and to exclude waves of frequencies included in the transmitting frequency band (Tx); - at least one secondary transmit port (24) intended to carry waves with frequencies within the transmit frequency band (Tx) and to exclude waves with frequencies within the receive frequency band (Rx). The two asymmetric junctions (32, 32', 232, 232') are arranged such that: - the first axial access (36A) of the first asymmetric junction (32) is connected to at least one primary port (20); - the second axial access (36B) of the first asymmetric junction (32) is connected to one of at least one secondary receive port (22) and at least one secondary transmit port (24); and - the first axial access (36A') of the second asymmetric junction (32') is connected to the other among at least one secondary receiving port (22) and at least one secondary transmitting port (24).

6. Radio frequency exciter according to claim 5, comprising a first secondary receiving port (22A), a second secondary receiving port (22B), a first secondary transmitting port (24A) and a second secondary transmitting port (24B).

7. Radio frequency exciter (16) according to claim 6, wherein: - the first secondary receiving port (22A) is intended to carry right-hand circularly polarized waves, the second secondary receiving port (22B) is intended to carry left-hand circularly polarized waves, the radio frequency exciter (16) further comprising a septum polarizer (66, 72) connecting the first secondary receiving port (22A) and the second secondary receiving port (22B) to the junction device (30); or - the first secondary receiving port (22A) is intended to carry horizontally polarized waves, the second secondary receiving port (22B) is intended to carry vertically polarized waves, the radio frequency exciter (16) further comprising a polarization diplexer (78, 84) connecting the first secondary receiving port (22A) and the second secondary receiving port (22B) to the junction device (30).

8. Radio frequency exciter (16) according to claim 6 or 7, wherein: - the first secondary transmitting port (24A) is intended to carry right-hand circularly polarized waves, the second secondary transmitting port (24B) is intended to carry left-hand circularly polarized waves, the radio frequency exciter (16) further comprising a septum polarizer (68) connecting the first secondary transmitting port (24A) and the second secondary transmitting port (24B) to the junction device (30); or - the first secondary transmitting port (24A) is intended to carry horizontally polarized waves, the second secondary transmitting port (24B) is intended to carry vertically polarized waves, the radio frequency exciter (16) further comprising a polarization diplexer (74) connecting the first secondary transmitting port (24A) and the second secondary transmitting port (24B) to the junction device (30).

9. Radio frequency exciter (16) according to claim 7 or 8, wherein the first and second asymmetric junctions (32, 32') and / or the polarizer(s) 21 septum (66, 68, 72) and / or the polarization diplexer(s) (74) are formed in one piece.

10. Radio frequency wave transmission or reception system (10) comprising: - a radiating antenna (12), for example a radiating horn; - a radio frequency exciter (16) according to any one of the preceding claims, at least one primary port (20) of the radio frequency exciter (16) being connected to the radiating antenna (12).

11. A method (100) for manufacturing a radio frequency exciter (16) according to any one of claims 1 to 9, comprising: - an additive manufacturing step (110) comprising the additive manufacturing of the joining device (30); - a step (120) of arranging the junction device (30) such that: - the first axial access (36A) of the first asymmetric junction (32) is connected to at least one primary port (20); - the second axial access (36B) of the first asymmetric junction (32) is connected to one of at least one secondary receiving port (22) and at least one secondary transmitting port (24); - the first axial access (36A') of the second asymmetric junction (32') is connected to the other among at least one secondary receiving port (22) and at least one secondary transmitting port (24); - the first radial access (38A) of the first asymmetric junction (32) is connected to the second radial access (38B') of the second asymmetric junction (32'); - the second radial access (38B) of the first asymmetric junction (32) is connected to the first radial access (38A') of the second asymmetric junction (32').

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