IL322795A - Waveguide array having a trapezoidal cross-section - Google Patents

Description

STO12-141-PCT Waveguide array having a trapezoidal cross-section Technical field id="p-1" id="p-1"

[0001] The present invention relates to a trapezoidal section waveguide network and an antenna array comprising such a waveguide network.

Background art id="p-2" id="p-2"

[0002] Radiofrequency waveguide networks are widely used in many areas of telecommunications, particularly in satellite telecommunications. id="p-3" id="p-3"

[0003] Constraints related to the payload of satellites limit the space and weight available for all onboard components, particularly antenna components and other passive radiofrequency devices. id="p-4" id="p-4"

[0004] Additive manufacturing of such devices offers the advantage of complex geometries that optimize the space occupied by the devices and a manufacturing method that requires very few assembly steps, thereby reducing manufacturing time and cost. However, additive manufacturing also has certain constraints, particularly in terms of device geometry, in order to be feasible. id="p-5" id="p-5"

[0005] There is therefore a need for passive radiofrequency devices that are optimized for compactness, minimized in weight, and have a geometry suitable for additive manufacturing. id="p-6" id="p-6"

[0006] There is also a need for alternative waveguide network geometries to offer designers greater design freedom. 2 STO12-141-PCT id="p-7" id="p-7"

[0007] Waveguide networks often comprise matrix arrangements of waveguides with rectangular cross-sections, or honeycomb arrangements of waveguides with hexagonal cross-sections. In these arrangements, each waveguide except those at the edge of the array shares all its walls with adjacent waveguides. This sharing of walls reduces the weight and footprint of the array. id="p-8" id="p-8"

[0008] However, additive manufacturing of waveguide networks with rectangular or hexagonal cross-sections is difficult due to the number of cantilevered walls during printing. id="p-9" id="p-9"

[0009] Networks formed from circular waveguides arranged in a matrix have also been devised. In this arrangement, each waveguide shares only a very limited length of its contour with its neighbors, for example four points. The ratio between the surface area of the channels and the surface area of the walls is therefore unfavorable.

Brief summary of the invention id="p-10" id="p-10"

[0010] One aim of the present invention is to provide a waveguide network free from the limitations present in the prior art. id="p-11" id="p-11"

[0011] Another aim of the invention is to provide a waveguide network that facilitates additive manufacturing. id="p-12" id="p-12"

[0012] Another purpose of the invention is to provide a waveguide network that limits the number of assembly steps during manufacture. id="p-13" id="p-13"

[0013] Another purpose of the invention is to provide a waveguide network with optimized compactness. id="p-14" id="p-14"

[0014] Another objective of the invention is to provide a waveguide network that is lighter than waveguide networks in the prior art. 3 STO12-141-PCT id="p-15" id="p-15"

[0015] According to the invention, these objectives are achieved in particular by means of a waveguide network obtained by additive manufacturing comprising waveguides arranged in pairs so as to form at least one pair of waveguides, each pair of waveguides comprising: a first waveguide with a trapezoidal cross-section, at least one of the angles of which is different from 90°, and; a second waveguide with a trapezoidal cross-section, at least one of the angles of which is different from 90°; characterized in that the first waveguide and the second waveguide have a common wall. id="p-16" id="p-16"

[0016] The trapezoidal shape with at least one angle other than 90° reduces or eliminates horizontal overhanging surfaces during printing. id="p-17" id="p-17"

[0017] The trapezoidal section is that of the waveguide channel. id="p-18" id="p-18"

[0018] In one embodiment, the common wall corresponds to a small base of the trapezoidal sections of the first and second waveguides. id="p-19" id="p-19"

[0019] According to one embodiment, the common wall corresponds to a long base of the trapezoidal sections of the first and second waveguides. id="p-20" id="p-20"

[0020] According to one embodiment, the common wall corresponds to a side adjacent to the bases of the trapezoidal sections of the first and second waveguides. id="p-21" id="p-21"

[0021] The first waveguide may be arranged to transmit a first polarization, and the second waveguide may be arranged to transmit a second polarization. id="p-22" id="p-22"

[0022] The first waveguide may be arranged to transmit a first polarization, and the second waveguide may be arranged to transmit the same first polarization. id="p-23" id="p-23"

[0023] According to one embodiment, the number of waveguides is greater than or equal to four so as to form at least two pairs of waveguides, the common wall of the 25 4 STO12-141-PCT waveguides of a first pair corresponds to the small base of the trapezoidal sections, and the common wall of the waveguides of a second pair corresponds to the long base of the trapezoidal sections. id="p-24" id="p-24"

[0024] According to one embodiment, the number of waveguides is greater than or equal to four and the pairs of waveguides are arranged contiguously in a first direction such that two successive pairs in the first direction have at least one waveguide wall in common. id="p-25" id="p-25"

[0025] According to one embodiment, the number of waveguides is greater than or equal to four and the waveguide pairs are arranged contiguously in a first direction and in a second direction, such that two successive pairs in the first direction have at least one waveguide wall in common and such that two successive pairs in the second direction have at least one waveguide wall in common. id="p-26" id="p-26"

[0026] According to one embodiment, at least one common waveguide wall of the successive pairs in the first direction corresponds to a base of the trapezoidal sections of the waveguides and at least one common waveguide wall of the successive pairs in the second direction corresponds to a side adjacent to the bases of the trapezoidal sections of the waveguides. id="p-27" id="p-27"

[0027] According to one embodiment, an inner wall of the first waveguide and an inner wall of the second waveguide comprise a ridge. id="p-28" id="p-28"

[0028] According to one embodiment, two inner walls of the first waveguide and two inner walls of the second waveguide include a ridge. id="p-29" id="p-29"

[0029] According to one embodiment, the two inner walls provided with ridges correspond to bases of the trapezoidal section of the first and second waveguides. id="p-30" id="p-30"

[0030] According to one embodiment, each trapezoidal section is an isosceles trapezoid or a parallelogram. 25 STO12-141-PCT id="p-31" id="p-31"

[0031] According to one embodiment, the waveguide network is adapted to operate as a combiner network. id="p-32" id="p-32"

[0032] These objectives are also achieved by means of a dual-polarization antenna array obtained by additive manufacturing comprising: a waveguide network according to one of the preceding claims, a plurality of radiating elements, each radiating element being coupled to the end of exactly one pair of waveguides of the array. id="p-33" id="p-33"

[0033] According to one embodiment of the antenna array, the waveguide network comprises at least eight waveguides and the pairs of waveguides are arranged contiguously in a first direction and in a second direction, such that two successive pairs in the first direction have at least one waveguide wall in common and such that two successive pairs in the second direction have at least one waveguide wall in common. id="p-34" id="p-34"

[0034] The invention may also relate to a waveguide network for transmitting a single polarization, comprising several waveguide lines (or slices), each line comprising power combiners, bent waveguides and straight sections, in which the straight waveguides of each line have trapezoidal sections, the waveguides of each line being alternately in a first orientation and in a second orientation head-to-tail with respect to the first orientation, so that each waveguide within each line shares a side adjacent to the bases of the trapezoid with the neighboring waveguide in the line. The network may comprise several lines, the trapezoid bases of adjacent lines being shared. id="p-35" id="p-35"

[0035] The invention may also relate to a waveguide network for transmitting two polarizations, comprising at least one waveguide line (or slice) for transmitting a first polarization signal and at least one second waveguide line (or slice) for transmitting a second polarization signal, each line comprising power combiners, bent waveguides and straight sections, in which the straight waveguides of each line have trapezoidal sections, the waveguides of each line being alternately in a first orientation and in a second orientation head-to-tail with respect to the first orientation, such that each waveguide within each line shares a side adjacent to the bases of the trapezoid with 6 STO12-141-PCT the neighboring waveguide in the line. The trapezoid bases of adjacent lines may be shared.

Brief description of the figures id="p-36" id="p-36"

[0036] Examples of the invention are shown in the description illustrated by the attached figures, in which: • Figures 1a and 1b schematically illustrate two cross-sectional views of a pair of trapezoidal waveguides.

• Figure 2a schematically illustrates two cross-sectional views of waveguide arrays arranged in one direction.

• Figure 3 schematically illustrates a cross-sectional view of a network of waveguides arranged in two directions.

• Figure 4 shows a cross-sectional view of an antenna array comprising a network of waveguides with a trapezoidal cross-section.

• Figure 5 shows a perspective sectional view of an antenna array comprising a network of waveguides with a trapezoidal cross-section.

• Figure 6 illustrates a perspective view of an antenna array comprising a waveguide network according to the present invention.

Example(s) of embodiments of the invention id="p-37" id="p-37"

[0037] The present invention relates primarily to a waveguide network in which the cross-section of each waveguide is trapezoidal in shape, with at least one of the angles being other than 90°. In other words, the geometric profile obtained by intersecting the waveguide with a plane essentially perpendicular to the direction of 20 7 STO12-141-PCT wave propagation in the waveguide is a trapezoid, i.e., a quadrilateral having at least one pair of parallel sides, called the bases of the trapezoidal , at least one of the angles of which is different from 90°. A trapezoid has a small base and a long base. id="p-38" id="p-38"

[0038] A trapezoidal section with at least one angle other than 90° excludes all rectangular and square sections. However, a parallelogram-shaped section with at least one angle other than 90° is covered by this definition. For the remainder of this text, the term "trapezoidal section" shall be understood to mean "trapezoidal section with at least one angle other than 90°." id="p-39" id="p-39"

[0039] The waveguide network preferably comprises an even number of waveguides. The waveguides of the network may be arranged in pairs to form waveguide pairs 12. Each pair 12 of waveguides comprises a first waveguide 10 for propagating an electromagnetic wave having a first polarization P1 and a second waveguide 11 for propagating an electromagnetic wave having a second polarization P2. Thus, each pair of waveguides supports two polarizations. These pairs are characterized in that the waveguides forming them share a wall 100. This shared wall corresponds to a base of the trapezoidal sections of each waveguide, or to a side adjacent to the bases. id="p-40" id="p-40"

[0040] It is also possible to provide a network of the type described in this description, but in which each waveguide transmits the same polarization. id="p-41" id="p-41"

[0041] As illustrated in Figures 1a and 1b, the common wall 100 of the first waveguide 10 and the second waveguide 11 may correspond to the large base of the trapezoidal section or to the small base of the trapezoidal section. The common wall may also correspond to a side adjacent to the bases of the trapezoidal sections. id="p-42" id="p-42"

[0042] In an embodiment illustrated in Figures 2a and 2b, the waveguide network comprises a plurality of pairs 12 of trapezoidal section waveguides arranged in a direction. Two successive pairs share at least one waveguide wall. In other words, a waveguide of a first pair shares a wall with a waveguide of a second pair. 8 STO12-141-PCT id="p-43" id="p-43"

[0043] In an embodiment illustrated in Figure 2a, a plurality of pairs 12 consisting of pairs of waveguides sharing a large base of the trapezoidal section with each other can be arranged in an X direction. Two successive pairs may share a waveguide wall corresponding to a small base of the trapezoidal section as shown in Figure 2a or corresponding to a large base (not shown). id="p-44" id="p-44"

[0044] In an embodiment shown in Figure 2b, a plurality of pairs 12 consisting of pairs of waveguides sharing a small or large base of the trapezoidal section can be arranged in a Y direction. Two successive pairs share two waveguide walls corresponding to sides adjacent to the bases of the trapezoidal sections. id="p-45" id="p-45"

[0045] In a mode of realization illustrated in Figure 3, a plurality of pairs 12 consisting of pairs of waveguides (10, 11) sharing a small or large base of their trapezoidal section may be arranged in a first X direction and a second Y direction. The resulting array 1 consists of a matrix of waveguides with a trapezoidal section. id="p-46" id="p-46"

[0046] These arrangements notably allow to obtain dense and compact waveguide networks. The trapezoidal shape of the sections allows for optimal use of space by avoiding any free space between adjacent waveguides. In addition, the sharing of walls between certain adjacent waveguides makes it possible to reduce the overall weight of the network, since some walls are shared. The shared walls therefore serve two waveguides simultaneously. id="p-47" id="p-47"

[0047] In one embodiment, at least one inner wall of the waveguides is provided with a ridge. The ridges(s) allow, in particular, the miniaturization of the network and/or promote the transmission of certain modes by limiting higher-order modes. The ridges(s) may be arranged on any inner wall of the waveguides. Ridges within the same waveguide may be identical or have different geometries. id="p-48" id="p-48"

[0048] The trapezoidal cross-section waveguides described may be straight or bent. It is also possible to provide combiners, for example Y- or H-shaped combiners, with several branches of trapezoidal cross-section as described. 9 STO12-141-PCT id="p-49" id="p-49"

[0049] In an embodiment illustrated in Figure 4, the waveguides of the network are provided with several ridges. In particular, the waveguides comprise a ridge on the small base of the trapezoidal section and a ridge on the large base of the trapezoidal section. id="p-50" id="p-50"

[0050] The walls of the grooves can be adapted to facilitate their additive manufacturing. For example, the angles between the walls of the ridges and the printing direction can be adapted to limit the cantilevered portions. Alternatively or additionally, the ridges may include rounded portions to facilitate additive printing. id="p-51" id="p-51"

[0051] The present invention also relates to a dual-polarization antenna array obtained by additive manufacturing and including a waveguide network 1 as described above and a plurality of radiating elements coupled to the waveguide pairs 12. id="p-52" id="p-52"

[0052] In an embodiment illustrated in Figure 5, each radiating element is connected to a pair 12 of waveguides so as to transmit or receive a dual-polarization signal (P1, P2), the first waveguide 10 of the pair 12 propagating the first polarization P1 and the second waveguide 11 of the pair 12 propagating the second polarization P2. id="p-53" id="p-53"

[0053] In an embodiment not shown, each radiating element is connected to a single waveguide. id="p-54" id="p-54"

[0054] The connection between a radiating element and a waveguide, or a pair of waveguides, may include one or more section adapters, for example if the section of the radiating elements is circular, rectangular or more generally non-trapezoidal. id="p-55" id="p-55"

[0055] The antenna array shown in Figure 5 can be combined with a plurality of identical arrays to form a matrix array. The trapezoidal shape of the waveguide sections allows a dense and compact array to be obtained by limiting the free space between the antenna arrays. Such a matrix array is shown in Figure 6. id="p-56" id="p-56"

[0056] Additive manufacturing is particularly well suited to the production of such waveguide networks and antenna arrays. It allows for optimized density of the various STO12-141-PCT waveguide networks. In addition, it drastically reduces manufacturing time and costs. The production of monolithic parts using additive manufacturing minimizes the number of parts that need to be assembled to obtain the final device. In some cases, this number of parts is equal to one and requires no assembly. id="p-57" id="p-57"

[0057] In one embodiment, waveguide network 1 operates as a combiner/splitter and/or as a beamforming network.

Reference numerals of the figures 1 Waveguide network First waveguide 11 Second waveguide 12 Waveguide pair 14 Ridge Common wall 2 Antenna array

Claims (16)

11 STO12-141-PCT Claims

1. A waveguide network (1) obtained by additive manufacturing comprising waveguides arranged in pairs to form at least one waveguide pair (12), each waveguide pair comprising: a first waveguide (10) with a trapezoidal cross-section, and a second waveguide (11) with a trapezoidal cross-section; characterized in that the first waveguide and the second waveguide have a common wall (100).

2. Network according to claim 1, wherein the common wall corresponds to a small base of the trapezoidal sections of the first and second waveguides.

3. Network according to claim 1, wherein the common wall corresponds to a long base of the trapezoidal sections of the first and second waveguides.

4. Network according to claim 1, wherein the common wall corresponds to a side adjacent to the bases of the trapezoidal sections of the first and second waveguides.

5. Network according to one of the preceding claims, the first waveguide being intended to propagate a first polarization (P1) and the second waveguide being intended to propagate a second polarization (P2).

6. Network according to one of the preceding claims, the number of waveguides being greater than or equal to four so as to form at least two pairs of waveguides (12), the common wall of the waveguides of a first pair corresponding to the small base of the trapezoidal sections and the common wall of the waveguides of a second pair corresponding to the long base of the trapezoidal sections.

7. Network according to one of the preceding claims, the number of waveguides being greater than or equal to four and the pairs of waveguides being arranged contiguously in a first direction so that two successive pairs in the first direction have at least one waveguide wall in common. 12 STO12-141-PCT

8. Network according to one of the preceding claims, the number of waveguides being greater than or equal to four and the pairs of waveguides being arranged contiguously in a first direction and in a second direction, such that two successive pairs in the first direction have at least one waveguide wall in common and such that two successive pairs in the second direction have at least one waveguide wall in common.

9. Network according to the preceding claim, wherein the at least one common waveguide wall of the successive pairs in the first direction corresponds to a base of the trapezoidal sections of the waveguides and the at least one common waveguide wall of the successive pairs in the second direction corresponds to a side adjacent to the bases of the trapezoidal sections of the waveguides.

10. Network according to one of the preceding claims, wherein an inner wall of the first waveguide (10) and an inner wall of the second waveguide (11) comprise a ridge (14).

11. Network according to one of the preceding claims, wherein two inner walls of the first waveguide (10) and two inner walls of the second waveguide (11) comprise a ridge (14).

12. Network according to the preceding claim, wherein the two inner walls correspond to bases of the trapezoidal section of the first and second waveguides.

13. Network according to one of the preceding claims, wherein each trapezoidal section is an isosceles trapezoid or a parallelogram.

14. Waveguide network according to one of the preceding claims, adapted to operate as a combiner network.

15. A dual-polarization antenna array (2) obtained by additive manufacturing comprising: a waveguide network (1) according to one of the preceding claims, 13 STO12-141-PCT a plurality of radiating elements (20), each radiating element being coupled to the end of exactly one pair (12) of waveguides of the network.

16. Antenna array (2) according to the preceding claim, wherein the waveguide network (1) comprises at least eight waveguides and the waveguide pairs are arranged contiguously in a first direction and in a second direction, such that two successive pairs in the first direction have at least one waveguide wall in common and such that two successive pairs in the second direction have at least one waveguide wall in common.