Waveguide array with a circular cross-section
The waveguide array with elliptical cross-sections addresses miniaturization and manufacturing challenges by enhancing wall-to-channel ratio and facilitating additive manufacturing, resulting in a lighter, more compact design with improved mechanical rigidity and thermal conductivity.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2024-03-11
- Publication Date
- 2026-04-02
AI Technical Summary
Existing waveguide arrays face challenges in miniaturization, weight reduction, and additive manufacturing feasibility due to shared wall configurations that affect weight and volume, and manufacturing complexity with rectangular or hexagonal cross-sections.
A waveguide array with non-circular elliptical cross-sections and shared wall sections, featuring elliptical or teardrop shapes, enhances wall-to-channel surface area ratio, facilitating additive manufacturing and reducing weight and volume through reinforced areas and improved heat dissipation.
The elliptical cross-sections enable easier manufacturing, reduce assembly steps, and achieve a lighter, more compact waveguide array with enhanced mechanical rigidity and thermal conductivity, optimizing space utilization and reducing manufacturing time and costs.
Smart Images
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Abstract
Description
Technical Field
[0001] The present invention relates to a waveguide array and an antenna array including such a waveguide array.
Background Art
[0002] Radio frequency waveguide arrays are widely used in many fields of the communication field, particularly satellite communication.
[0003] Due to the constraints on the satellite's mounting capacity, particularly the mounting parts of antenna components and other radio frequency passive devices, the space and weight that can be secured for all the mounted parts are limited.
[0004] The additive manufacturing of such devices has the advantages of realizing complex geometries that optimize the space occupied by the device and providing a manufacturing method with a minimized assembly process, thereby reducing manufacturing time and cost. However, in terms of feasibility, additive manufacturing has certain constraints, particularly regarding the geometry of the device.
[0005] Therefore, there is a need for passive radio frequency devices that optimize miniaturization, minimize weight, and have a geometry suitable for additive manufacturing.
[0006] Alternative geometries of waveguide arrays are also needed to expand the designer's freedom in design.
[0007] Waveguide arrays typically comprise a matrix arrangement of waveguides with a rectangular cross-section or a honeycomb arrangement of waveguides with a hexagonal cross-section. In these arrangements, except for the ends of the array, each waveguide shares all its walls with adjacent waveguides. This sharing of walls reduces the weight and volume of the array.
[0008] Contrary to what one might intuitively imagine, in such a configuration where all walls are shared, it may not always be possible to obtain the optimal ratio of the surface area of the (waveguide) to the surface area of the walls. In fact, the walls of the waveguide need to be thick enough to ensure the rigidity of the array and to dissipate heat. This crucial thickness of all the walls tends to increase the weight of the array and its occupied area.
[0009] Furthermore, the additive manufacturing of waveguide arrays with rectangular or hexagonal cross-sectional shapes is difficult due to the large number of cantilevered walls involved in the printing process.
[0010] Arrays of rectangular cross-section waveguides arranged in a matrix have already been developed. In this arrangement, each waveguide shares only a very limited length, for example, four points, with the adjacent waveguides. This results in an unfavorable ratio of the surface area of the (waveguide) channel to the surface area of the wall. [Overview of the project] [Problems that the invention aims to solve]
[0011] One of the objectives of the present invention is to provide a waveguide array that is free from the limitations of the prior art.
[0012] Another object of the present invention is to provide a waveguide array that facilitates additive manufacturing.
[0013] Another objective of the present invention is to provide a waveguide array that reduces the number of assembly steps in its manufacturing process.
[0014] Another object of the present invention is to provide an optimally miniaturized waveguide array.
[0015] Another object of the present invention is to provide a waveguide array that is lighter than conventional waveguide arrays. [Means for solving the problem]
[0016] In this invention, these objectives are achieved, in particular, by a waveguide array obtained by additive manufacturing. This waveguide array comprises a plurality of waveguides, each set of a plurality of waveguides arranged in at least one set. Each set of waveguides comprises a first waveguide channel and a second waveguide channel. The first and second channels have a non-circular elliptical cross-section with an axis of symmetry and at least one non-linear portion, and The first and second waveguides share a common wall section.
[0017] An ellipse is defined as a cross-section formed by a differentiable closed curve, possessing at least one axis of symmetry, and having a shape that is somewhat similar to an ellipse. In this application, ellipse shapes, egg shapes, stadium shapes, and peanut shapes are exemplified as ellipses.
[0018] Compared to arrays consisting of waveguides with a circular cross-section, the elliptical shape increases the portion of the shared wall between adjacent waveguides, thereby improving the ratio of the wall surface area to the channel surface area.
[0019] The elliptical shape also offers the advantage of being generally easier to manufacture than other shapes that have more cantilevered sections.
[0020] Elliptic shapes cannot be perfectly juxtaposed on a plane without gaps between them. While these gaps are generally considered undesirable, the present invention utilizes them to create a structure that locally thickens the walls, strengthens the rigidity of the device, and improves heat dissipation by filling them at least partially. As a result, the other parts of the shared walls between these reinforced areas can be printed at a relatively thin thickness. Thus, counterintuitively, the imperfect juxtaposition of waveguide channels having the shapes described in the claims allows for the creation of reinforced areas, which ultimately allows for thinner other walls, resulting in a reduction in weight and volume compared to arrays consisting of waveguides with rectangular or hexagonal cross-sections where all walls are shared.
[0021] In a modified example, by providing an opening for releasing heat in these strengthening regions, the weight of the array is further reduced.
[0022] In the first embodiment, the first channel and the second channel have a non-circular elliptical cross-section with two symmetry axes.
[0023] The waveguide channel alternately includes a convex first end, a concave connection portion, and a convex second end along its longest dimension.
[0024] The connection portion may include two concave walls (concave sections) facing each other.
[0025] The dimensions of the channel at the first end and the second end are larger in the direction perpendicular to the longest dimension than at the connection portion.
[0026] In this embodiment, the cross-section of the channel is thus substantially in the shape of a peanut.
[0027] The contours of the first end and the second end form an arc of at least 190°, preferably at least 210°. The connection portion may connect these ends in a direction tangential to these arcs.
[0028] The concave wall (concave section) of the concave connection portion may include a root portion.
[0029] The two inner walls of the first waveguide and the two inner walls of the second waveguide may each include a root portion.
[0030] The array may include a first row (or row portion) of waveguides juxtaposed along its longest extension direction and a second row (or row portion) of waveguides juxtaposed along its longest extension direction, and the second row is offset by half the length of one waveguide with respect to the first row. Thereby, the convex portions of each waveguide abut against the convex connection portions of the waveguides in the adjacent row.
[0031] In another embodiment, the waveguide channel alternates between a first convex end and a second end consisting of two non-parallel walls along its longest dimension.
[0032] The waveguide channel then effectively takes on the shape of a water droplet.
[0033] Non-parallel walls are joined together to form the second end of the channel.
[0034] The contour of the first convex end may be in the shape of a circular arc of at least 180°.
[0035] Non-parallel walls may be provided with a first convex end extending along two tangents.
[0036] Each channel may have one or more ridges.
[0037] The array in this second embodiment is The first row of waveguides is arranged in a direction perpendicular to the longest extension direction of the first row of waveguides, The waveguide may include a second row of waveguides arranged in the same direction as the longest extension direction of the second row of waveguides, the two rows being arranged in opposite directions, and the second row being offset from the first row by half the width of one waveguide.
[0038] The array may comprise a third row of waveguides arranged perpendicular to the longest extension direction of the plurality of waveguides in the third row of waveguides, and a fourth row of waveguides arranged in the same direction as the longest extension direction of the plurality of waveguides in the fourth row of waveguides, with the third row being arranged alongside the second row.
[0039] The waveguide array may further be equipped with a Y-shaped connector to function as a coupler array.
[0040] A dual-polarization antenna array formed by additive manufacturing may comprise the waveguide array described above and a plurality of radiating elements. Each radiating element is coupled to one end of the waveguide of the array.
[0041] Section matching sections may be provided between each waveguide and each radiating element.
[0042] A septum may be provided between each radiating element and one set of waveguides.
[0043] Such an antenna array may have at least eight waveguides. Each pair of waveguides is arranged adjacent to each other along a first and a second direction, with two pairs of waveguides adjacent along the first direction sharing at least one waveguide wall, and two pairs of waveguides adjacent along the second direction sharing at least one waveguide wall.
[0044] The present invention also relates to a waveguide array for transmitting single polarization. This waveguide array comprises multiple rows (or multiple rows) of multiple waveguides, each row comprising multiple power couplers, multiple bent waveguides, and multiple straight sections, and each row's multiple straight waveguides having the sections described in the first or second embodiment.
[0045] The present invention also relates to a waveguide array for transmitting dual polarization. This waveguide array comprises at least one row (or row portion) of waveguides for transmitting a first polarization signal and at least one second row (or row portion) of waveguides for transmitting a second polarization signal. Each row comprises power couplers(s), bent waveguides(s), and straight sections(s). In this waveguide array, the straight waveguides(s) of each row(s) have the sections(s) described in the first or second embodiment.
[0046] Several embodiments of the present invention are shown in the description in the accompanying drawings. [Brief explanation of the drawing]
[0047] [Figure 1] Figure 1 schematically shows a cross-sectional view of a waveguide according to the first embodiment. [Figure 2] Figure 2 schematically shows a cross-sectional view of a waveguide according to the first embodiment (which here has a single ridge). [Figure 3]Figure 3 schematically shows a cross-sectional view of the waveguide array according to the first embodiment. [Figure 4] Figure 4 schematically shows a cross-sectional view of the waveguide array according to the second embodiment. [Modes for carrying out the invention]
[0048] Figure 1 shows a cross-sectional view of a substantially peanut-shaped waveguide according to the first embodiment. This waveguide comprises a core 100, for example, made of metal and manufactured by additive manufacturing, and a conductive coating 101 applied to the inner wall of the core.
[0049] The cross-section of the waveguide channel 10 is elliptical, not circular, and has a first axis of symmetry along the longest extension direction x, and a second axis of symmetry along the y direction perpendicular to this extension direction.
[0050] Along the longest extension direction x, the channel 10 alternates between a first convex end 110, a concave portion 111, and a second convex end 112. At both ends, the dimensions of the channel in the y-direction perpendicular to the longest extension direction x are greater than the dimensions at the connection points.
[0051] The connection section 11 has two recessed portions 1110 and 1111 that face each other. These recessed portions form two opposing ridges, allowing for filtering of specific transmission modes. As shown in Figure 2, this filtering can be enhanced by providing an additional ridge 14 in either section of the recessed portion. Multiple such ridges can be installed within the channel.
[0052] The walls of the ridge section 14 may be adapted to facilitate additive manufacturing. For example, the angle between the walls of the ridge section and the printing direction may be adapted to limit the cantilevered portion. Alternatively or additionally, the ridge section may have rounded portions to facilitate additive printing.
[0053] The contours at both ends 110 and 112 may form an arc of at least 190°, preferably at least 210°. It is also possible to install ends of different shapes.
[0054] The connecting section(s) 1110 are extended tangentially to the connected end section(s), forming a continuous and differentiable curve.
[0055] The waveguide walls shown in Figure 1 are essentially constant. As shown in Figure 3, an array is formed by arranging multiple waveguides of this shape side by side. Subsequently, portions of the walls of adjacent waveguides are shared.
[0056] As shown in Figures 1 and 2, when waveguides are placed side by side, areas not occupied by the element pattern in Figure 1 remain. These areas are filled with metal during additive manufacturing, forming mechanically reinforced and heat-dissipating regions. This improves mechanical rigidity and thermal conductivity, allowing for thinner waveguide walls in other parts, thereby reducing the weight and size of the array.
[0057] These reinforced areas 20 may optionally be provided with longitudinal openings 21 to further improve the cooling performance and reduce the weight of the array.
[0058] A waveguide array preferably comprises an even number of waveguides. The waveguides in the array are arranged in pairs to form multiple sets of waveguides. Each set of waveguides comprises a first waveguide 10 (propagating electromagnetic waves with a first polarization P1) and a second waveguide 11 (propagating electromagnetic waves with a second polarization P2). Thus, each set of waveguides handles two polarizations. These sets are characterized in that the two waveguides forming the set share a portion of the wall.
[0059] While we can provide an array of one example of the multiple waveguides described in this explanation, we can also provide a waveguide array in which each waveguide transmits the same polarization.
[0060] A waveguide array is formed by creating multiple rows of waveguides. The first row 120 is formed by arranging waveguides along the x-direction perpendicular to their maximum extension direction. The second row 121 is formed by arranging other waveguides along their maximum extension direction. The two rows are assembled with the second row 121 offset from the first row 120 by half the width of one waveguide.
[0061] Figure 4 shows a waveguide array formed by additive manufacturing according to the second embodiment. Each waveguide 10, 11 has a substantially teardrop-shaped cross-section.
[0062] The waveguide comprises a core 100, for example, made of metal, formed by additive manufacturing, and a conductive coating 101 applied to its inner wall.
[0063] The cross-section of the waveguide channel 10 is elliptical, not circular, and has a single axis of symmetry along the longest extension direction x.
[0064] Along the longest extension direction x, the channel 10 alternates between a first convex end 113 and a second end consisting of two non-parallel walls 114 and 115. These non-parallel walls are joined together. The non-parallel walls 114 and 115 extend along two tangents to the first convex end 113.
[0065] In this example, the contour of the first convex end forms an arc of at least 180°. Other convex curves are also possible.
[0066] Channels 10 and 11 may have one or more ridges (not shown) at any part of the channel in order to filter out a specific transmission mode.
[0067] The waveguides according to the first and second embodiments described may be straight or curved. Couplers with multiple branches, such as Y-shaped or H-shaped couplers, may also be provided in the form of the described cross-section.
[0068] A waveguide array is formed by creating multiple rows of waveguides. The first row 130 is formed by juxtaposing waveguides along the x-direction perpendicular to their longest extension direction. The second row 131 is formed by juxtaposing other waveguides along their longest extension direction. The two rows are assembled by shifting the second row 131 relative to the first row 130 by half the width of one waveguide, and reversing the leading and trailing ends. This allows non-parallel (two types) walls 114, 115 to be shared between the multiple waveguides of the two rows.
[0069] The waveguide (array) may comprise a third waveguide array 132 arranged side-by-side in the x-direction, and a fourth waveguide array 133 arranged side-by-side with respect to the third waveguide array, offset by half the width of one waveguide. The second and third arrays are adjacent, and the waveguides are in contact with each other through a portion of the wall at their first convex end.
[0070] When multiple teardrop-shaped waveguides are placed side by side, areas not covered by the basic pattern remain, particularly between the second and third rows. These areas can be filled with metal during additive manufacturing to form mechanically reinforced and heat-dissipating regions. By enhancing the mechanical rigidity and thermal conductivity of these areas, the wall thickness of other waveguides can be reduced, thereby reducing the weight and size of the (waveguide) array.
[0071] The present invention also relates to a dual-polarization antenna array 2 manufactured by additive manufacturing, comprising the above-described waveguide array 1 and a plurality of radiating elements connected to the set of waveguides.
[0072] In one embodiment, each radiating element is connected to a pair of waveguides 10 and 11 to transmit and receive dual-polarization (P1, P2) signals. The first waveguide 10 of the pair propagates the first polarization P1, and the second waveguide 11 of the pair propagates the second polarization P2.
[0073] Additive manufacturing is particularly well-suited for the production of such waveguide and antenna arrays. In fact, it allows for the optimization of the density of different waveguide arrays. Furthermore, it significantly reduces manufacturing time and costs. Indeed, by using integrally molded parts through additive manufacturing, the number of parts required to assemble the final device can be minimized. In some types, there is only one part, eliminating the need for assembly.
[0074] In one embodiment, the waveguide array 1 functions as a coupler or divider, or as a beamforming array. Typically, the waveguide array further includes a Y-junction that functions as a coupler array.
[0075] In certain embodiments, one or both of the waveguide array and the antenna array further include at least one of the following elements: a septum, an impedance matching element, a power coupler, a power divider, and a passive filter.
[0076] The arrays described are typically designed to operate in at least one of the following frequency bands: X-band, Ku-band, Ka-band, QV-band, Ku / Ka-band, and Ka / QV-band.
Claims
1. A waveguide array (1) obtained by additive manufacturing, comprising a plurality of waveguides arranged in sets to form at least one set of waveguides, wherein each set of waveguides is First waveguide channel (10), Second waveguide channel (11) and In the waveguide array provided, The first channel and the second channel each have a non-circular elliptical cross-section having an axis of symmetry (x) and at least one non-linear portion, and The first waveguide and the second waveguide have a shared wall portion (100) A waveguide array (1) characterized by the following features.
2. The array according to claim 1, wherein the first waveguide channel propagates a first polarization (P1), and the second waveguide channel propagates a second polarization (P2).
3. The array according to claim 1 or 2, wherein the first channel and the second channel have a non-circular elliptical cross-section having two axes of symmetry (x, y).
4. The array according to claim 3, wherein the first waveguide channel and the second waveguide channel alternately have a first convex end (110), a concave connecting portion (111), and a second convex end (112) along their longest dimension (x).
5. The array according to claim 4, wherein the dimensions of the channels (10, 11) at both ends are greater in the direction (y) perpendicular to the longest dimension (x) than at the connecting portion.
6. The array according to claim 5, wherein the connecting portion comprises two concave sections facing each other.
7. The array according to claim 6, wherein the contours of both aforementioned ends form an arc of at least 210°.
8. The array according to claim 6 or 7, wherein the concave section further comprises a ridge portion (14).
9. The array according to any one of claims 1 to 8, wherein the two inner walls of the first waveguide (10) and the two inner walls of the second waveguide (11) are provided with a ridge portion (14).
10. The array according to any one of claims 3 to 9, wherein the waveguide channel has a substantially peanut-shaped geometric form.
11. A first row of waveguides (120) is arranged in parallel along the direction (x) of the longest extension of multiple waveguides in the first row of waveguides (120), The second row (121) of waveguides is arranged in parallel along the direction of the longest extension of the plurality of waveguides, The array according to any one of claims 1 to 10, wherein the second row is offset from the first row by half the length of one waveguide.
12. The array according to claim 11, wherein the multiple spaces between the channels form a rigidity-enhancing region.
13. The array according to claim 12, wherein the multiple spaces between the channels form reinforced regions (20) having openings (21).
14. The array according to claim 1, wherein the waveguide channel comprises a first convex end (113) and a second end formed by two non-parallel walls (114, 115) along its longest dimension (x).
15. The array according to claim 14, wherein the non-parallel walls (114, 115) are joined together.
16. The array according to claim 14 or 15, wherein the contour of the first convex end (113) is in the shape of an arc of at least 180°.
17. The array according to any one of claims 14 to 16, wherein the non-parallel walls (114, 115) have the first protruding end extending along two tangents.
18. The array according to any one of claims 14 to 17, wherein each of the first waveguide channel and the second waveguide channels (10, 11) is provided with a ridge portion.
19. The first row of waveguides (13) is arranged in a direction (x) perpendicular to the direction of the longest extension of multiple waveguides in the first row of waveguides (130), The system comprises a second row of waveguides (13) arranged in the direction of the longest extension of the plurality of waveguides in the second row of waveguides (131), The array according to any one of claims 14 to 18, wherein both rows are arranged in opposite directions to each other, and the second row is offset from the first row by half the width of one waveguide.
20. The third row of waveguides (132) consists of a third row of waveguides (132) arranged in a direction perpendicular to the direction of the longest extension of the waveguides, The array according to claim 19, further comprising a fourth row (133) of waveguides arranged in the direction of the longest extension of a plurality of waveguides in the fourth row (133) of waveguides, wherein the third row is arranged in parallel with the second row.
21. A waveguide array according to any one of claims 1 to 20, further comprising a Y-shaped junction that functions as a coupling array.
22. A waveguide array (1) according to any one of claims 1 to 21, Each radiating element is coupled to one end of the waveguide of the array, and a plurality of the radiating elements A dual-polarization antenna array (2) obtained by additive manufacturing, comprising the above.
23. The waveguide array (1) comprises at least eight waveguides, and multiple pairs of the waveguides are arranged adjacent to each other along the first and second directions. Two sets of contiguous waveguides along the first direction share at least one waveguide wall, The antenna array (2) according to claim 22, wherein two sets of antennas that are continuous along the second direction share at least one waveguide wall.