High-frequency module with an array of equal-phase waveguides

Abstract

To provide a passive high-frequency module that suppresses conventional limitations. The method includes: a first layer (3) having an array of radiating elements (30), each radiating element (30) having a cross-section that supports at least one wave propagation mode; a second layer (4) forming an array of a plurality of waveguides (40), each waveguide being connected to one radiating element of the first layer; A high frequency module in which one or more of the waveguides (40) of the array of waveguides includes at least one phase adjustment element (500) that eliminates the phase shift of the waveguides relative to each other at the nominal frequency of the waveguides.

Description

[Technical field]

[0001] The present invention relates to a radio frequency module (radio frequency, RF) comprising an array of non-identical waveguides, the lengths of which may differ. The radio frequency module and the waveguides it comprises can be used to transmit equal phase signals despite the differences between the waveguides. The invention is particularly aimed at controlling, or minimizing or eliminating, the phase shift between the waveguides. [Background technology]

[0002] It is known to use waveguides of the same length in a waveguide array in order to keep the phase the same over a wide frequency band. For example, Patent Document 1 discloses that the effective path lengths of two waveguides are equal.

[0003] Patent Document 2 discloses a Butler matrix with multiple hybrids and waveguides so that the output of the Butler matrix has the same amplitude and a constant phase difference with respect to the input signal. The transmission lines connecting the hybrids need to be designed to have the same transmission length, or the amplitude and phase need to be adjusted according to the change in the results. Furthermore, bending the waveguides makes the path complicated.

[0004] Patent Document 3 discloses a wavelength demultiplexer having an input channel waveguide 1 , a plurality of output channel waveguides 5 , and an arrayed waveguide 8 interposed between the input waveguide 1 and the output waveguide 5 .

[0005] Patent Document 4 describes a high-frequency module that includes a waveguide having a ridge that widens the single-mode bandwidth.

[0006] US Pat. No. 5,399,633 describes a collection of waveguides of different lengths, the cross-sections of which are designed to compensate for the resulting phase shift.

[0007] Directly radiating array (DRA) antenna arrays are also known that combine multiple phase-shifted radiating elements (elementary antennas) for improved gain and directivity. The signals received by or transmitted from the different radiating elements are amplified with variable gain and phase shifted relative to each other to control the shape of the receive and transmit lobes of the array.

[0008] At high frequencies, e.g. microwave frequencies, each of the different radiating elements is connected to a waveguide which transmits the received signal to the high frequency electronic module or which supplies the high frequency signal to be transmitted to this radiating element. The signals transmitted or received by each radiating element can also be separated according to polarization using a polarizing section.

[0009] The assembly formed by the array of radiating elements (elementary antennas), the associated waveguides, the filters and polarizers used is called in this text a passive radio frequency module. The waveguides and the associated polarizers are called the feed network. This assembly is intended to form the passive part of a Direct Radiating Array (DRA).

[0010] Arrays of radiating elements for high frequencies, especially microwave frequencies, are difficult to design. In particular, it is often desirable to place the different radiating elements of the array as close together as possible to reduce the amplitude of the transmission or reception side lobes in directions other than the preferred transmission or reception direction. However, this small pitch between the different radiating elements of the array is incompatible with the minimum size required by the polarization section and the spatial requirements of the electronic amplification and phase shifting circuits upstream of the polarization section. The size of the polarization section and the electronic system usually determines the minimum pitch between the different radiating elements of the array. This results in a wider pitch and unwanted transmission or reception side lobes. However, other high frequency modules require the radiating elements to be spaced further apart, for example to have a transmission cone. For example, US Pat. No. 6,399,433 describes an assembly of non-linear waveguides of various lengths and shapes, which allows the pitch between the radiating elements to be reduced or increased to modulate the side lobes. By adapting the cross sections of the different waveguides, the phase shift caused by the different lengths is compensated.

[0011] This results in limitations in the space requirements and / or weight reduction of the RF module, which is detrimental for applications that are sensitive to these weight and space requirement variables, such as those related to the aerospace and aviation industries.

[0012] Thus, waveguides need to be improved for control of those differences, particularly the phase shift inherent in different lengths of waveguide, without having to change their overall space requirements, particularly the cross-sectional shape and dimensions of the waveguide. [Prior art documents] [Patent documents]

[0013] [Patent Document 1] US Patent Application Publication No. 2013 / 154764 [Patent Document 2] US Patent Application Publication No. 2012 / 112963 [Patent Document 3] JP 2003-185858 A [Patent Document 4] International Publication No. 2020 / 194270 [Patent Document 5] US Patent Application Publication No. 2021 / 218151 [Patent Document 6] International Publication No. 2019 / 229515 Summary of the Invention [Problem to be solved by the invention]

[0014] One object of the invention is therefore to propose a passive high-frequency module for forming the passive part of a direct radiating array or DRA, which is free from or minimizes the limitations of known devices. [Means for solving the problem]

[0015] These objects are achieved in particular by a radio frequency module as set forth in the independent claims and as detailed by the dependent claims.

[0016] The radio frequency module specifically includes a first layer having an array of radiating elements, each radiating element having a cross-section that supports at least one wave propagation mode.

[0017] There may further be a second layer forming an array of waveguides.

[0018] There may also be a fourth layer forming an array of ports.

[0019] The second layer may be interposed between the first layer and the fourth layer.

[0020] Each waveguide may be for transmitting a high frequency signal in one direction or the other between a port in the fourth layer and a radiating element.

[0021] The surface area of ​​the first layer may be different from the surface area of ​​the fourth layer.

[0022] The waveguides may have different lengths and shapes, but preferably have the same cross section. One or more of the waveguides comprises at least one phase adjusting element.

[0023] The waveguides therefore have several cumulative functions: they allow the transmission of signals between the ports of the fourth layer and the radiating elements of the first layer, and they allow the pitch of the radiating elements and the pitch of the ports of the fourth layer to be chosen independently. They also help to correct or eliminate phase shifts inherent in the construction of the module. Furthermore, they allow more compact arrangements that would be impossible or more difficult with existing means.

[0024] This arrangement allows the pitch between the radiating elements in the first layer to be small in order to reduce the amplitude of unwanted side lobes ("grating lobes").

[0025] For this reason, the pitch (p1) between two radiating elements in the first layer is preferably less than or equal to λ\2, where "λ" is the wavelength at the maximum operating frequency.

[0026] The arrangement of the waveguides converging from the fourth layer towards the radiating elements allows the ports on the fourth layer to be spaced farther apart. The wide pitch between the ports allows, for example, the electronic amplification and phase shifting circuits feeding each port to be placed very close to each port, reducing the constraints on the size of this circuitry. This wide pitch also allows large enough polarizing sections to be placed close to each port, if necessary, to effectively separate the signals according to their polarization.

[0027] In another embodiment, the surface area of ​​the first layer is greater than the surface area of ​​the fourth layer, and the waveguides are spaced apart between the fourth layer and the first layer. This embodiment allows for the use of relatively large radiating elements, but does not require a larger port layer.

[0028] The arrangement of the radiating elements in the first layer may be different from the arrangement of the ports in the fourth layer. For example, the radiating elements in the first layer may be arranged in a rectangular matrix M×N, while the ports in the fourth layer may be arranged in a rectangular matrix K×L, where M is different from K and N is different from L. This different arrangement may involve different shapes, for example a rectangular arrangement on one layer and a circular, elliptical, cross, hollow rectangular, polygonal, etc. arrangement on the other layer.

[0029] The high frequency module may include a third layer interposed between the second layer and the fourth layer.

[0030] The elements in the third layer are capable of transforming the signal.

[0031] The third layer may comprise an array of elements that provide a cross-sectional match between the cross-section of the output of the ports in the fourth layer and the cross-section of the different shapes of the waveguides. This type of third layer may be provided especially when only the ports or only the waveguides are ridges.

[0032] A third layer interposed between the second and fourth layers may comprise an array of polarisers as elements.

[0033] In one variant, the radio frequency module may comprise an external polarizer immediately following the element that radiates into air.

[0034] A third layer interposed between the second and fourth layers may comprise a filter.

[0035] Each radiating element of the first layer may be provided with at least one ridge parallel to the signal propagation direction.

[0036] The radiating elements in the first layer may have no ridges and may comprise open waveguides or rectangular, circular, pyramidal or splined horns.

[0037] The radiating element may have an external cross-section that is square, rectangular, or preferably hexagonal, circular or elliptical.

[0038] The pitch (p1) between the two radiating elements may vary within the module.

[0039] Each waveguide in the second layer is preferably designed to transmit either the fundamental mode only, or the fundamental mode and a single degenerate mode.

[0040] The different waveguides of the second layer may have different lengths, but the waveguides are of equal phase at the wavelength of interest, in particular due to the presence of at least one phase adjusting element.

[0041] The channels of the different waveguides may be non-linear. The waveguides in the second layer may be curved.

[0042] Different waveguides in the second layer may have different curvatures, for example the peripheral waveguides may be more curved than the central waveguides.

[0043] The port in the fourth layer may form the input of the polariser.

[0044] The first ends of all of the waveguides lie in a first plane and the second ends of all of the waveguides lie in a second plane.

[0045] The module is advantageously a module manufactured by additive manufacturing.

[0046] Additive manufacturing allows in particular the production of complex shaped waveguides, in particular curved waveguides that converge in a funnel shape between the layers of radiating elements and the layers of polarizing sections.

[0047] "Additive manufacturing" should be understood to mean any method of manufacturing parts by adding material according to computer data stored on a computer medium and defining a model of the part. In addition to stereolithography and selective laser melting, the expression also refers to other manufacturing methods involving the hardening or solidification of liquids or powders, including, in particular, but not limited to, methods based on binder jetting, DED (Direct Energy Deposition), EBFF (Electron Beam Freeform), FDM (Fused Deposition Modeling), PFF (Plastic Freeform), aerosol, BPM (Particle Manufacturing), powder bed fusion, SLS (Selective Laser Sintering), ALM (Additive Layer Manufacturing), Polyjet, EBM (Electron Beam Melting), photopolymerization, etc. However, manufacturing by stereolithography or selective laser melting is preferred, since they produce parts with relatively clean and smooth surfaces.

[0048] The module is preferably designed as a single piece.

[0049] Manufacturing the module as a single piece helps reduce costs by eliminating the need for assembly, and also helps ensure that the different components are accurately positioned relative to each other.

[0050] The invention also relates to a module comprising an element as described above and an electronic circuit with amplifiers and / or phase shifters connected to each port. The invention further relates to any object, in particular a communications object, comprising such a module. Such an object may in particular be dedicated to the aerospace and aviation sectors. It may for example be a communications satellite. The invention further relates to a method for designing and manufacturing the module which is the subject of this description.

[0051] An embodiment of the present invention is illustrated by the accompanying drawings in which: [Brief description of the drawings]

[0052] [Figure 1] 2 is a schematic side view of different layers of a module according to the invention; [Diagram 2]Two embodiments of the third layer, where each element of the third layer has one or two inputs on the fourth layer side. [Figure 3A] FIG. 2 is a schematic diagram of the second and third layers of an example of a module according to the prior art. [Figure 3B] FIG. 2 is a schematic diagram of the second and third layers of an example of a module according to the prior art. [Figure 3C] FIG. 2 is a schematic diagram of the second and third layers of an example of a module according to the prior art. [Figure 4] FIG. 1 is a schematic diagram of a waveguide according to one embodiment described herein. [Figure 5A] FIG. 2 is a schematic diagram of a waveguide according to another embodiment described herein. [Figure 5B] FIG. 2 is a schematic diagram of a waveguide according to another embodiment described herein. [Figure 6A] FIG. 2 is a schematic diagram of a waveguide according to another embodiment described herein. [Figure 6B] FIG. 2 is a schematic diagram of a waveguide according to another embodiment described herein. [Figure 6C] FIG. 2 is a schematic diagram of a waveguide according to another embodiment described herein. [Figure 7A] FIG. 2 is a schematic diagram of a waveguide according to another embodiment described herein. [Figure 7B] FIG. 2 is a schematic diagram of a waveguide according to another embodiment described herein. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0053] FIG. 1 shows a passive radio frequency module 1 according to a first embodiment of the invention, for forming the passive part of a direct radiating array or DRA.

[0054] In this example, the high frequency module 1 includes four layers: a layer 3, a layer 4, a layer 5, and a layer 6.

[0055] Of these layers, the first layer 3 comprises a two-dimensional array of N radiating elements 30 (antennas) that transmit electromagnetic signals into the ether or receive received signals.

[0056] The second layer 4 comprises an array of waveguides 40 .

[0057] The third layer 5 is optional and may be incorporated into the second layer 4. If present, the third layer 5 comprises an array of elements 50, such as polarisers or cross-sectional adapters.

[0058] The fourth layer 6 comprises a two-dimensional array, e.g., a rectangular matrix, of N ports 60 of waveguides 40. Each port 60 forms an interface with an active element of the DRA, such as an amplifier and / or phase shifter, and is part of a beamforming (also called spatial filtering or channel forming) array. The ports therefore connect the waveguides to electronic circuitry, allowing signals to be injected into the waveguides, or conversely, allowing electromagnetic signals in the waveguides to be received.

[0059] When using linearly or circularly polarized antennas, the 2N ports 60A, 60B may be used.

[0060] As an alternative to integrating the polarizers in the third layer 5, one could also use a layer of polarizers between the first layer 3 with the radiating elements and the second layer 4 with the waveguides, or integrate the polarizers in the radiating elements. This solution has the advantage of moving the polarizers closer to the radiating elements and avoiding the complexity of transmitting signals with multiple polarizations in each waveguide.

[0061] This module 1 is intended for use in a multi-beam environment. The radiating elements 30 are preferably close to each other such that the pitch p1 between two adjacent radiating elements is smaller than a wavelength at the nominal frequency at which the module 1 is intended to be used. This reduces the amplitude of the transmit and receive side lobes.

[0062] Figures 3A to 3C show different views of an example of a module according to the prior art, without the third and fourth layers. In this example, the waveguide 40 and the radiating element 30 have a square cross section with four ridges symmetrically arranged on the inner wall. The waveguides converge towards the first layer 3. In the embodiment shown in Figures 1 and 3A to 3C, the radiating element 30 is constituted by a waveguide with, for example, two, three or four ridges 300, spaced apart at equal angular intervals, for example.

[0063] The invention is characterized by the presence of one or more phase adjustment elements 500 arranged protruding from the inner surface of the waveguide 40. The phase adjustment elements 500 may be arranged as a replacement for or in addition to the bumps or peaks 300 known from the prior art. In this case, the phase adjustment elements 500 serve to eliminate phase differences inherent to variations in length and / or shape of the waveguides 40 of a given assembly. They also make it possible to limit or eliminate variations in shape and dimensions of the waveguides 40 of a given assembly.

[0064] The phase adjustment element 500 removes the phase difference, allowing for the generation of a signal without a phase shift. However, the phase adjustment element 500 allows for the phase shift to be adjusted, for example to better control side lobes. Thus, a particular phase shift can be induced by the phase adjustment element 500, for example, limited to a particular waveguide 40, depending on its position in the waveguide matrix or other factors.

[0065] Different phase shifts can be obtained in different waveguides of a given RF module by using different phase adjustment elements for each waveguide, for example the cross section of these elements, their length, height and / or their number may be different for each waveguide to produce different phase shifts and for example to compensate for length differences between the different waveguides.

[0066] Thus, the waveguides 40 may have a cross-section with a constant or substantially constant shape and size. The cross-sectional shape essentially refers to the outer contour of a given waveguide 40. In one aspect, the shape and cross-section of the inner surface of the waveguide is excluded. In another aspect, the shape or internal elements of the waveguide other than the inner shell whose shape corresponds to the outer shell is excluded. The cross-sectional shape refers not only to the geometric shape of the cross-section but also to its dimensions. The cross-sectional shape of a given waveguide 40 is preferably constant or substantially constant over the entire length of the waveguide 40. The cross-sectional shapes of all the waveguides 40 of a given assembly are preferably the same, even if the lengths of the waveguides 40 are different.

[0067] Variations in length between the waveguides 40 will likely result in a phase shift that needs to be at least partially adjusted or compensated for. Other variables, such as variations in the longitudinal shape of the waveguides, may result in phase shifts, even if the lengths are the same. In particular, variations in the radius of curvature of the waveguides 40, or variations in the number of curves, may result in such phase shifts. Other variables, such as variations in the roughness and combination of materials used to manufacture the waveguides, may also affect the phase shift. Internal structures disposed in the waveguides, such as ridges or protrusions or peaks, may also result in phase shifts that need to be removed or compensated for. It is understood that the present invention applies to any assembly of waveguides 40 that results in an unwanted phase shift in the signal, whether due to variations in the lengths of the waveguides or other structural or construction variables of the waveguides.

[0068] The phase adjustment element 500 according to the present invention allows the elimination of a phase shift or in any case the control of the phase shift. This means that the waveguides of some or all of a given assembly comprising one or more phase adjustment elements 500 are in phase. The phase adjustment element 500 alternatively allows a phase shift control. This means in particular that it is possible to reduce the phase shift differences between the waveguides inherent in the structure of the waveguides of the module, or to make the phase shift similar or identical. This also means that it is possible to create a controlled phase shift, which may be required, for example, to limit or eliminate side lobes or interference between radiating elements. The phase adjustment element 500 is used to adjust a phase shift that is initially expected as a result of the waveguide structure, but which ultimately deviates from the expected value. In this case, the phase adjustment element serves to correct construction or manufacturing defects in order to obtain the required phase shift value for each waveguide in the module.

[0069] The phase adjustment element 500 may, for example, be in the form of a change in the inner diameter of the waveguide 40. FIG. 4 shows an example of such a waveguide 40, with an inner surface SI forming a maximum diameter dmax and a minimum diameter dmin, and an outer surface SE with a cross section and shape that is constant along its length L. The illustrated waveguide 40 is straight, but it does not have to be straight. It may also have a cross section of any of the shapes previously disclosed herein. For example, the cross section of the waveguide may be hexagonal or polygonal, square, rectangular, circular or elliptical, or any other suitable shape. The phase adjustment element 500 may be in the form of a gradual decrease in the inner diameter of the waveguide 40 between the maximum diameter dmax and the minimum diameter dmin over the entire length L or only a portion of the entire length L. In the latter scenario, it is a localized decrease in the inner diameter that can, for example, adjust the effect of the curvature of the waveguide. Such an arrangement may be localized in one or more central parts of the waveguide 40, or indeed in one or more of its ends. The values ​​of the maximum diameter dmax and the minimum diameter dmin can be determined as a function of the length L of the waveguide 40 or the difference in length with an adjacent waveguide. Alternatively or additionally, the slope of the change in diameter between the values ​​dmax and dmin, or indeed the length of the tuning element 500, is determined as a function of the length L of the waveguide 40 or the difference in length with an adjacent waveguide.

[0070] For example, the value of the maximum diameter dmax may correspond to the diameter of the inner surface SI, or in fact to a fraction of the order of magnitude of 70%, 80%, or about 90%, or about 95% of the diameter of the inner surface SI.

[0071] The minimum diameter dmin may correspond to a value of the order of 60% or approximately 50%, or indeed 40%, of the diameter of the inner surface SI.

[0072] When multiple phase adjusting elements 500 are disposed within a waveguide, each may have its own maximum diameter dmax and minimum diameter dmin values.

[0073] Diameter should be understood here to mean the dimension of the interior space of the waveguide 40, regardless of the cross-sectional geometry of the waveguide 40. It therefore applies equally to circular or elliptical cross-sectional shapes and to polygonal cross-sectional shapes.

[0074] In a cross-section of a waveguide 40 with a phase adjustment element 500, the phase adjustment element may cover the entire inner surface SI. Alternatively, the phase adjustment element 500 may be located on a portion of the cross-section of the waveguide 40. Figures 5A and 5B show an example of a waveguide 40 with a circular cross-section with a phase adjustment element 500 covering a portion of the cross-section of the waveguide 40. Figure 5A shows the corresponding cross-section and Figure 5B shows a longitudinal section.

[0075] The proportion of the cross-section that is provided with the phase adjustment element 500 may be, for example, of the order of 10% or more, or of the order of 20% or more, or of the order of 30% or more of the inner surface SI corresponding to this cross-section. It may even be 100% of the inner surface SI corresponding to a given cross-section. From one end of the phase adjustment element 500 to the other, the proportion of the inner surface SI occupied by the phase adjustment element 500 may vary, for example, from about 10% to about 90%, or from 20% to about 80%, or from 30% to about 70% of the inner surface SI. In other words, the surface area occupied by the phase adjustment element 500 varies (may vary) along the waveguide 40 from a minimum surface area Smin value to a maximum surface area Smax value.

[0076] The thickness of phase adjusting element 500 across a given cross-section of the waveguide need not be the same across the entire surface area occupied by the phase adjusting element.

[0077] When phase adjusting element 500 covers only a portion of the cross-sectional surface area, it may be oriented parallel to the longitudinal axis of waveguide 40. Alternatively, phase adjusting element 500 may be offset from the longitudinal axis of waveguide 40 and may adopt a helical configuration along the inner surface SI of waveguide 40.

[0078] The surface of the phase adjustment element 500 facing the inside of the waveguide 40 may be rounded and concave, as shown in Figure 5A, or alternatively rounded and protruding, as shown in Figure 6A, or may assume other shapes, particularly angular shapes such as triangles or rectangles, as shown in Figures 7A and 7B.

[0079] When multiple phase adjustment elements 500 are arranged in the waveguide, they may be arranged in the same section of the waveguide 40, i.e. opposite each other. Fig. 6A shows a cross section of a waveguide 40 with two phase adjustment elements 500 arranged opposite each other. Fig. 6B shows a longitudinal section of a waveguide 40 with multiple adjustment elements 500a, 500b, 500c, 500d arranged in a staggered manner along the waveguide. Fig. 6C shows another cross section in which the phase adjustment elements 500a, 500b, 500c are staggered and oriented along an axis different from the longitudinal axis of the waveguide 40. In particular, they have an angle of the order of 10° to about 40° with the longitudinal axis.

[0080] 7A and 7B show another example of a waveguide 40 having a rectangular cross section and including multiple differently shaped phase adjustment elements 500a, 500b, 500c. It should be understood that each of the illustrated shapes can be selected independently of the others and that a given shape can be replicated in a given waveguide 40. The cross-sectional shape of the phase adjustment element 500 can be selected from rounded concave shapes, rounded protruding shapes, polygonal shapes, or combinations of these shapes, among others.

[0081] In one embodiment, the phase adjustment element 500 described herein may be placed in addition to other elements already present in the waveguide 40 that are not involved in the elimination or controlled modulation of the phase shift, such as grooves, peaks, or tips, particularly when these elements alone are not capable of eliminating the desired phase shift of a signal from one waveguide 40 to another. For example, a radiating element with a ridge 300 allows dimensions smaller than the wavelength of the signal to be transmitted or received. In particular, the diameter of the waveguide may be smaller than the wavelength of the signal. However, such elements are not necessarily isophasic and therefore require phase shift correction. Thus, the phase adjustment element 500 allows for the elimination or control of phase shift while maintaining the small dimensions of the waveguide 40 made possible by the presence of the ridges. Examples of waveguides with such elements, such as longitudinal ridges or chevrons, have also been shown, helping to increase the single-mode bandwidth of each waveguide device. WO2020194270 provides one of these examples. Nevertheless, there may still be a need to eliminate or modulate the phase shift. This is made possible by the phase adjustment element herein. Structures added to the waveguide 40 for specific reasons may also cause a phase shift that needs to be corrected.

[0082] In another embodiment, the phase adjustment elements 500 are placed in the waveguide 40 without the other elements mentioned above. In a particular arrangement, they may be placed as a replacement for elements already present in the waveguide 40 and having a function other than modulating or removing the phase shift. In this case, the phase adjustment elements 500 perform the function of the element they replace while modulating or removing the phase shift. For example, the phase adjustment elements 500 may be placed in the waveguide 40 to replace one or more of the ridges 300 that the waveguide 40 includes. The adapted shape of the phase adjustment elements 500 thus allows the maintenance of small dimensions while controlling the phase shift.

[0083] Whether phase adjusting element 500 is placed in place of or in addition to other elements already present in waveguide 40, it is possible in all cases to avoid or limit the variations in waveguide cross section that are typically required to remove or correct phase shifts. The increased uniformity of the waveguide diameter allows for more compact devices.

[0084] In one embodiment, the diameter and / or surface area occupied by the phase adjustment element 500, placed in place of or in addition to other elements not involved in the correction or modulation of the phase shift, is constant. In other words, the values ​​of the maximum diameter dmax and the minimum diameter dmin, or indeed the surface area occupied for a given cross section of the waveguide 40, are equal for a given phase adjustment element 500.

[0085] The phase adjustment elements 500 may be arranged symmetrically and / or in a symmetrical or regular arrangement within the waveguide 40. Alternatively, the phase adjustment elements 500 may have no particular symmetry and thus be asymmetric. They may also be arranged irregularly, i.e., non-uniformly spaced, within the waveguide, in which case they may be locally concentrated at locations where the geometry of the waveguide 40 changes, such as at or near curves.

[0086] Within an assembly of waveguides 40, each of the waveguides 40 may have a specific effect on the phase shift of the signal relative to the signals associated with the other waveguides 40 of the assembly. This specific effect may be the result of differences in length or other factors. The phase adjustment elements 500 are designed to compensate in a specific way for the effects of the different waveguides on the phase shift of the signal. In other words, the number, shape, size and arrangement of the phase adjustment elements 500 may vary from one waveguide 40 to another.

[0087] Within an assembly of waveguides 40, some waveguides may not have phase adjusting elements 500, while other waveguides 40 may have such phase adjusting elements. Thus, some or all of the waveguides in the assembly may be provided with one or many of the same or different phase adjusting elements 500.

[0088] Within an assembly of waveguides 40, all of the waveguides preferably have the same cross-section, both shape and size, so that the phase shift is not corrected by changes in the shape or size of their cross-section. Nevertheless, a waveguide assembly may include waveguides that differ from one another in their cross-sectional shapes and sizes (without cross-sectional differences that allow for the desired elimination, modulation or correction of the phase shift).

[0089] Within the assembly, the waveguides 40 may be separated from one another. Alternatively, they may be connected to one another so as to maintain their relative position. They may form an integral assembly. The connection between the waveguides may be established, for example, by some of the first layer 3, the third layer 5 and the fourth layer 6. Retaining elements may be manufactured in the form of bridges between the different waveguides. Alternatively, the waveguides may be in direct contact with one another along their entire length or over part of their length.

[0090] The array of radiating elements 30 in the first layer 3 comprises N radiating elements 30. The radiating elements 30 may be arranged in a rectangular, square or other shaped matrix suitable to the requirements. For example, the radiating elements may be in a line with the number of radiating elements varying across the line, the general shape of the layer being an octagon. The radiating elements 30 may be phase shifted on successive lines, the value of the phase shift being smaller than the pitch p1 between two adjacent elements 30 on the same line. Any polygonal or substantially circular shape of the first layer 3 may be made. The radiating elements 30 may be arranged in a triangular, rectangular or diamond shape with aligned or phase shifted lines.

[0091] The phase and amplitude of each radiating element in the first layer 3 helps to achieve a high degree of separation between the different beams. The sub-wavelength radiating elements reduce the effect of side lobes in the area of ​​interest.

[0092] The radiating elements supporting at least one propagation mode may implement any shape, including rectangular, circular or rounded shapes. The radiating elements may or may not be ridged.

[0093] The radiating element 30 may be single or dual polarized. The polarization may be linear, tilted or circular.

[0094] The pitch p1 between two radiating elements 30 of the first layer 3 is preferably less than or equal to λ / 2, where "λ" is the wavelength at the maximum frequency for which the module is designed.

[0095] The radiating element may comprise a polarizing section, not shown, for example at the junction with the second layer 4. In another embodiment, not shown, the polarizing section is provided immediately after the free air section from which the transmission signal is radiated. As disclosed below, the polarizing section may also be provided in the third layer 5.

[0096] The second layer 4 comprises N waveguides 40. Each waveguide 40 transmits a signal from a port 60 and / or an element in the third layer 5 to a corresponding radiating element 30, and vice versa when receiving. The waveguides 40 also convert between the arrangement of elements 60 on the third layer 5 and fourth layer 6 and a different arrangement of radiating elements on the first layer 3.

[0097] The waveguide 40 may be curved in order to create a transition between a surface area of ​​the third or fourth layer 6 and a different surface area of ​​the first layer 3 of the radiating element. The waveguide thus forms a funnel-shaped chamber.

[0098] The second layer 4 may aid in matching the pitch between adjacent elements. In one embodiment, it may be designed to create a transition between the array of radiating elements 30 on the first layer 3 and a different array of ports 60 on the fourth layer 6. For example, the second layer 4 may create a transition between an array of elements or ports arranged in a rectangular matrix and an array of elements or ports arranged in a different matrix, or in a polygonal or circular shape.

[0099] At least some of the waveguides 40 may be curved. In particular, at least some of the waveguides are curved in two planes perpendicular to each other and parallel to the longitudinal axis of the module. These waveguides 40 are therefore S-curved in two planes perpendicular to each other and parallel to the main transmission direction of the signal.

[0100] The connection planes between the waveguide 40 and the radiating element 30 and between the waveguide 40 and the element 50 are preferably parallel to each other and perpendicular to the main transmission direction of the signal.

[0101] The waveguides 40 at the periphery of the second layer 4 may be curved and longer than the waveguides 40 closer to the center. The waveguides 40 closer to the center may be straight. Thus, the phase adjustment element 500 is different between the peripheral waveguides 40 and the central waveguides 40.

[0102] The dimensions of the internal channel through the waveguide 40 and the dimensions of the input portion 41, as well as the shape of the internal channel and the input portion 41, are determined as a function of the operating frequency of the module, i.e. the frequency at which the module 1 is manufactured, and the frequency of the electromagnetic signal at which a stable, and optionally minimum attenuation, transmission mode is obtained.

[0103] As disclosed above, different waveguides 40 of the second layer 4 may have different lengths and curvatures, which have an effect on their frequency response curves. These differences may be compensated for by the electronic systems feeding each port 60 or by processing the received signal. However, these differences are preferably at least partially compensated for by adapting one or more of the shape, number, size and configuration of the phase adjustment elements 500 herein. In one advantageous arrangement, the presence of the phase adjustment elements obviates the need for dedicated electronic elements to correct the phase shift.

[0104] All the waveguides have the same shape and cross-sectional dimensions.

[0105] If the different waveguides 40 of the second layer have the same length, some of the waveguides may be equipped with one or more phase adjusting elements 500 intended for local control of the phase shift of the signal. Such an arrangement makes it possible, for example, to influence the side lobes.

[0106] Alternatively, if the lengths of the different waveguides 40 are different from one waveguide to the other, the phase adjusting element 500 described herein serves to obtain an assembly of waveguides that are isophase at the wavelength of interest. Each waveguide of such an assembly of isophase waveguides serves to generate a signal that has no phase shift relative to the signals of the other waveguides of the assembly, despite differences in the lengths, curvatures or shapes of the waveguides. To this end, the different waveguides are provided with one or more phase adjusting elements designed to compensate for phase variations due to the different lengths or shapes of the different waveguides.

[0107] Also, despite the inclusion of the phase adjustment elements described herein, for control of the relative phase shift between the radiating elements and, for example, for control of beamforming, There may be the use of waveguides of different lengths and / or waveguides that produce different phase shifts; An array of active electronic phase shifting circuits may be used to exploit or compensate for these phase shifts.

[0108] In some embodiments, the second layer 4 may also comprise other waveguide elements, such as filters, polarization transformers or phase adapters.

[0109] Each waveguide 40 may be adapted for transmitting single polarized or dual polarized signals.

[0110] The third layer 5 is optional and comprises an element 50. In one embodiment, the element 50 provides a transition between the cross-section of the port 60 of the fourth layer 6 and the cross-section, which may be different, of the waveguide 40 of the second layer 4, which roughly corresponds to the cross-section of the radiating element of the first layer 3. For example, the waveguide of the third layer 5 provides a transition between the square or rectangular cross-section of the output of the port 60 and the cross-section of the waveguide 40 and the radiating element 30, which may be provided with a ridge 300.

[0111] In some embodiments, the elements 50 in the third layer 5 may transform the signal with other waveguide elements, such as filters, polarization converters, polarizers, phase adapters, etc.

[0112] The cross-sectional surface area of ​​the third layer 5 is preferably equal to the cross-sectional surface area of ​​the fourth layer 6 .

[0113] 2 shows an example of an element 50 in the third layer 5. In the embodiment at the top of the figure, this element 50 comprises an input 51 connected to a port 60 and an input 53 connected to an input 41 of a waveguide 40.

[0114] In the lower embodiment of the figure, this element 50 has two inputs 52A, 52B, each connected to a port 60A or 60B of the fourth layer, and an input 53 connected to input 41 of waveguide 40. In this embodiment, element 60 preferably comprises a polarisation section which couples or separates the two polarisations on ports 60A, 60B to or from the coupled signal on waveguide 40.

[0115] A phase adjustment element in a waveguide channel can filter high frequency signals in the waveguide (comb filter). This filtering can be controlled to attenuate unwanted frequency bands or propagation modes. Filtering can also be an undesired consequence of the presence of a phase adjustment element in a waveguide. In this case, the phase adjustment element is positioned and dimensioned to attenuate only frequencies far from the nominal frequency of the waveguide.

[0116] The invention is also directed to a method for manufacturing the module forming the subject matter herein.

[0117] The entire module 1 is preferably manufactured as a single part by additive manufacturing. It is also possible to manufacture the entire module 1 from several units assembled together, each unit comprising four layers: layer 3, layer 4, layer 5, layer 6, or at least a first layer 3, a second layer 4, and a fourth layer 6. It is also possible to manufacture by subtractive manufacturing or by assembly. It is also possible to combine additive manufacturing and subtractive manufacturing steps. The phase adjustment element 500 is preferably manufactured by additive manufacturing.

[0118] In one embodiment, the module is fabricated entirely from metal, for example aluminum, by additive manufacturing.

[0119] In another embodiment, the module 1 comprises a core made of a polymer, PEEK (polyetheretherketone), metal or ceramic and a conductive coating deposited on the surface of the core. The core of the module 1 may be made of a polymer material, ceramic, metal or alloy, for example aluminum, titanium or steel. The phase adjustment element 500 may be integrated into the core and made of the same material as the core. A conductive coating may cover the phase adjustment element 500.

[0120] The core of the module 1 may be fabricated by stereolithography or selective laser melting. The core may comprise different parts that are assembled together, for example by gluing or welding. In this case, the phase adjustment element 500 may be added to the core and associated with it by gluing or welding.

[0121] The metal layer of the coating may comprise a metal selected from Cu, Au, Ag, Ni, Al, stainless steel, brass or a combination of these metals.

[0122] One or more of the inner and outer surfaces of the core including the phase adjustment element 500 may be covered with a conductive metal layer, for example copper, silver, gold, nickel, plated by electroless deposition, the thickness of which may be, for example, between 1 micrometer and 20 micrometers, for example between 4 micrometers and 10 micrometers.

[0123] The thickness of this conductive coating must be sufficient to make the surface conductive at the selected radio frequency, which is usually accomplished by using a conductive layer with a thickness greater than the depth of the skin δ.

[0124] This thickness is preferably substantially constant over all interior surfaces to provide a finished part with close dimensional tolerances.

[0125] The conductive metal can be deposited on the inner and possibly outer surfaces by dipping the core into a series of successive baths, typically between 1 and 15 baths. Each bath contains a fluid with one or more reagents. Deposition does not require the application of an electric current to the core to be coated. Agitation and uniform deposition is achieved by moving the fluid through the transmission line and / or around the module 1, for example by pumping it, or by vibrating the core and / or a reservoir of fluid, for example with an ultrasonic vibration device to generate ultrasonic waves.

[0126] The conductive metal coating may cover all surfaces of the core without interruption. In another embodiment, module 1 comprises a sidewall having an exterior surface and an interior surface, the interior surface defining a channel, and the conductive coating covers the interior surface but not all of the exterior surface.

[0127] The module 1 may comprise a smoothing layer intended to at least partially smooth out any surface irregularities of the core. The conductive coating is deposited on the smoothing layer.

[0128] The module 1 may comprise a primer (or adhesive) layer deposited on the core so as to cover the core in a continuous manner.

[0129] The primer layer may be made of a conductive or non-conductive material. The primer layer serves to improve the adhesion of the conductive layer to the core. Its thickness is preferably less than the roughness Ra of the core and less than the resolution of the additive manufacturing method used to manufacture the core.

[0130] In one embodiment, the module 1 comprises a non-conductive core manufactured by additive manufacturing, which includes one or more phase adjustment elements 500, a primer layer, a smoothing layer, and a conductive layer in series. Thus, the primer layer and the smoothing layer serve to reduce the roughness of the surface of the waveguide. The primer layer serves to improve the adhesion between the conductive or non-conductive core and the smoothing layer and the conductive layer.

[0131] The shape of the module 1 may be determined by a computer file stored on a data storage medium and used to control an additive manufacturing device.

[0132] Furthermore, the shape, number, location, dimensions and other useful variables for phase adjusting elements 500 may be determined by a computer file stored in a data storage medium and used to control an additive manufacturing device.

[0133] Alternatively or additionally, the shape, number, location, dimensions and other useful variables for the phase adjustment elements 500 may be determined in whole or in part by a modeling program. Such a program may be used to determine at least some of the characteristics of the phase adjustment elements 500 required to remove or modulate the phase shift, depending, for example, on the characteristics of the waveguide used. Such a modeling program may take into account, for example, the length of the waveguide in question, its longitudinal shape, including curves, its cross-sectional shape, and other useful variables, as well as the wavelength of the signal. The modeling may include application of an algorithm to determine the phase shift of the waveguide as a function of the properties of the waveguide, e.g., an analytical or iterative algorithm, to determine one or more properties of the phase adjusting elements 500 required to correct, control or eliminate this phase shift. The properties of the phase adjusting elements 500 include one or more of their size, shape, their number, and their placement within the waveguide, including their orientation and position.

[0134] An artificial intelligence and / or deep learning module may be used to determine the effect of the phase adjusting element 500 on the phase shift and transfer function of the waveguide. Once the characteristics of the phase adjusting element are determined, they may be transferred to an additive manufacturing tool for fabricating the waveguide.

[0135] The module may be connected to electronic circuitry (for example in the form of a printed circuit mounted behind the third layer 5 or behind the fourth layer 6 of the ports) with amplifiers and / or phase shifters connected to each port.

Claims

1. a first layer (3) comprising an array of radiating elements (30), each radiating element (30) having a cross section that supports at least one wave propagation mode; a second layer (4) forming an array of a plurality of waveguides (40), each waveguide being connected to one radiating element of the first layer, the plurality of waveguides being of different lengths; In a high-frequency module (1) comprising:

1. A radio frequency module (1), characterized in that one or more waveguides (40) of the array of waveguides comprise at least one phase adjusting element (500) designed to remove or correct a phase shift of the waveguides relative to one another at the nominal frequency of the waveguides without changing the spatial requirements of the waveguides or the cross-sectional shape or dimensions of the waveguides.

2. 2. The high-frequency module according to claim 1, wherein the at least one phase adjustment element is disposed so as to protrude from an inner surface of the waveguide.

3. 2. The radio frequency module of claim 1, wherein the at least one phase adjustment element is arranged on the inner surface of the waveguide so as to vary the inner diameter between a maximum diameter (dmax) value and a minimum diameter (dmin) value over the length of the waveguide or a portion of its length.

4. 2. The radio frequency module of claim 1, wherein the more than one waveguide comprises more than one phase adjusting element located in the same portion of the waveguide or offset along the waveguide.

5. 2. The radio frequency module of claim 1, wherein the at least one phase adjustment element is oriented along an axis different from the longitudinal axis of the corresponding waveguide and forms an angle of between about 10° and 40° with the longitudinal axis.

6. 2. The high frequency module according to claim 1, wherein the cross-sectional shape of the at least one phase adjustment element is selected from a rounded concave shape, a rounded protruding shape, a polygonal shape, or a combination thereof.

7. 2. The radio frequency module according to claim 1, wherein the proportion of the inner surface (SI) occupied by one or more phase adjusting elements can vary from 10% to 100%, preferably from 20% to 100%, for a given cross section of the waveguide.

8. 2. The high-frequency module of claim 1, wherein the waveguides (40) of the array of waveguides (40) have a longitudinal internal structure in which phase shift is not eliminated or controlled, and the phase shift caused by the array of waveguides (40) is at least partially eliminated or corrected for some or each of the waveguides by the phase adjustment element (500).

9. the different waveguides have at least one of different lengths and different curvatures; the different waveguides have the same or different cross-sections; differences in frequency response and / or phase differences caused by different lengths and / or different curvatures of the waveguides remain unremovable or uncompensable; 2. The high frequency module of claim 1, wherein the phase shift caused by the array of waveguides is at least partially eliminated or corrected for some or each of the waveguides by the phase adjustment element.

10. 2. The high frequency module according to claim 1, wherein the different waveguides have at least one of a constant cross section and the same cross section.

11. the waveguide comprises a core; 2. The radio frequency module according to claim 1, wherein the at least one phase adjustment element (500) is directly coupled to the core or is integrated into the core.

12. 12. The high frequency module according to claim 11, wherein surfaces of the core and the at least one phase adjustment element (500) are covered with a conductive material.

13. 2. The high frequency module according to claim 1, wherein some of the plurality of waveguides (40) are not straight because the second layer spreads out like a morning glory.

14. 2. A radio frequency module according to claim 1, wherein the curvatures of the different waveguides (40) of the second layer (4) vary within the module.

15. a fourth layer having a port (60) connected to the waveguide at an end of the waveguide facing the radiating element; the surface area of ​​the first layer (3) is smaller than the surface area of ​​the fourth layer (6) such that the waveguide (40) moves towards each other between the fourth layer (6) and the first layer (3); or 2. The high frequency module of claim 1, wherein the surface area of ​​the first layer (3) is greater than the surface area of ​​the fourth layer (6) so that the waveguide (40) moves away from each other between the fourth layer (6) and the first layer (3).

16. 2. The radio frequency module of claim 1, wherein the phase adjustment element (500) allows elimination of phase shifts in the waveguides, so that all the waveguides are in phase at the wavelength of interest.

17. 10. The radio frequency module of claim 1, wherein the phase adjustment element (500) enables correction of a phase shift of a waveguide to produce a controlled phase shift.

18. 2. The radio frequency module of claim 1, wherein the at least one phase adjustment element is at least one of asymmetric and irregularly spaced at different intervals within the waveguide.

19. 2. The radio frequency module of claim 1, wherein the at least one phase adjustment element (500) allows the phase shift to be used in the absence of an array of active electronic phase shifting circuits for controlling the relative phase shift between radiating elements and, for example, for controlling beamforming.

20. 2. The radio frequency module according to claim 1, wherein the pitch (p1) between two radiating elements (30) on the first layer (3) is smaller than λ\2, where λ is the wavelength at the maximum operating frequency.

21. 2. A radio frequency module according to claim 1, wherein the pitch (p1) between two radiating elements (30) varies within the module.

22. 2. The radio frequency module according to claim 1, wherein the radiating element (30) of the first layer is a non-ridged portion and is constituted by an open waveguide having a square, rectangular, circular, hexagonal or octagonal cross section, or a pyramidal or splined horn.

23. 16. The radio frequency module of claim 15, further comprising a third layer (5) interposed between the second layer (4) and the fourth layer (6), the third layer (5) comprising an array of elements (50) that provide a cross-sectional match between the output cross-sections of the ports (60, 60A, 60B) of the fourth layer (6) and the cross-sections of the different shapes of the waveguides (40).

24. 16. The high frequency module according to claim 15, further comprising a third layer (5) interposed between the second layer (4) and the fourth layer (6), the third layer (5) comprising an array of multiple elements (50) comprising polarizing sections.

25. The high-frequency module according to claim 1 , further comprising a polarization section between the first layer and the second layer.

26. 16. The radio frequency module according to claim 15, further comprising a third layer (5) interposed between the second layer (4) and the fourth layer (6) and comprising a filter.

27. 2. The radio frequency module of claim 1, wherein each waveguide (40) has a square, rectangular, hexagonal, circular or elliptical cross section.

28. 2. The radio frequency module of claim 1, wherein each waveguide (40) is designed to transmit either a fundamental mode only, or a fundamental mode and a single degenerate mode.

29. 2. The radio frequency module of claim 1, wherein first ends of all of the waveguides (40) lie in a first plane and second ends of all of the waveguides lie in a second plane.

30. 10. The high frequency module according to claim 1, characterized in that it is made by additive manufacturing.

31. 2. The radio frequency module of claim 1, wherein the assembly of the waveguides (40) is in a single piece.

32. 2. The method of claim 1, further comprising modeling at least a portion of the characteristics of the at least one phase adjustment element (500) with one or more algorithms, the characteristics being selected from the number, size, arrangement, and shape of the phase adjustment elements (500).

33. The method of claim 32 , wherein the modeling comprises an artificial intelligence or deep learning module.

34. 33. The method of claim 32, comprising transmitting at least some of the variables from the modeling to an additive manufacturing device.

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