An overmolded corrugated waveguide with automatic mode optimization

Abstract

The present invention relates to the field of waveguide technology, specifically disclosing an overmolded corrugated waveguide capable of automatic mode optimization, comprising: an outer tube; an inner tube disposed at intervals within the outer tube, the inner wall of the inner tube being provided with a plurality of annular grooves spaced axially; and a deformable body disposed between the outer and inner tubes, the plurality of deformable bodies spaced axially, the deformable body comprising a plurality of memory alloy monomers disposed axially around the outer tube, the memory alloy monomers comprising a connecting portion and two deformable portions, the connecting portion being fixed to the inner wall of the outer tube, the first ends of the two deformable portions being interconnected by the connecting portion, and the second ends of the two deformable portions being in contact with the outer wall of the inner tube; wherein, when the memory alloy monomers are heated, the second ends of the two deformable portions move closer together, causing the radial length of the memory alloy monomers to increase, resulting in radial displacement of the inner tube. The overmolded corrugated waveguide capable of automatic mode optimization of the present invention reduces the generation of heterogeneous modes and achieves low-loss transmission of millimeter waves.

Description

Technical Field

[0001] The present invention relates to the field of waveguide technology, in particular to an over-molded corrugated waveguide capable of automatically performing mode optimization. Background Art

[0002] Millimeter-wave transmission technology is widely used in fields such as nuclear fusion plasma heating, dynamic nuclear polarization nuclear magnetic resonance experiments, and geophysical exploration. Currently, overmoded waveguides are the primary method for millimeter-wave transmission. However, due to the smooth inner walls of overmoded waveguides, factors such as the transmission of multiple millimeter-wave modes, waveguide steering, and installation errors can easily excite various spurious modes. These spurious modes are difficult to suppress, resulting in significant millimeter-wave transmission losses. Summary of the Invention

[0003] The purpose of the present invention is to provide an over-moded corrugated waveguide that can automatically perform mode optimization to reduce the generation of heterogeneous modes and achieve low-loss transmission of millimeter waves.

[0004] To achieve the above objectives, the present invention provides an over-molded corrugated waveguide capable of automatically performing mode optimization, comprising:

[0005] External control;

[0006] an inner tube, spaced apart inside the outer tube, wherein the inner wall of the inner tube is provided with a plurality of annular grooves, wherein the plurality of annular grooves are spaced apart along the axial direction; and

[0007] a deformable body disposed between the outer tube and the inner tube, wherein the plurality of deformable bodies are spaced apart along the axial direction, the deformable body comprising a plurality of memory alloy monomers disposed axially around the outer tube, the memory alloy monomers comprising a connecting portion and two deformable portions, the connecting portion being fixed to the inner wall of the outer tube, the first ends of the two deformable portions being connected to each other via the connecting portion, and the second ends of the two deformable portions being in contact with the outer wall of the inner tube;

[0008] Among them, when the memory alloy monomer is heated, the second ends of the two deformed parts move closer to each other, so that the radial length of the memory alloy monomer becomes longer, causing the inner tube to move radially inward; when the temperature of the memory alloy monomer decreases, the second ends of the two deformed parts separate from each other, so that the radial length of the memory alloy monomer becomes shorter, causing the inner tube to move radially outward.

[0009] In some embodiments, the outer tube wall has a water cooling channel, and the water cooling channel has a water inlet and a water outlet.

[0010] In some embodiments, the memory alloy monomer is a nickel-titanium-based shape memory alloy, a copper-based shape memory alloy, or an iron-based shape memory alloy.

[0011] In some embodiments, the surface of the memory alloy monomer has a nickel plating layer.

[0012] In some embodiments, the connecting portion and the deforming portion are integrally formed.

[0013] In some embodiments, the connecting portion is provided along a radial arc-shaped protrusion.

[0014] In some embodiments, the second end of the deformation portion has an extension portion, the extension portions of the two deformation portions are separated from each other, the extension portions abut against the outer wall of the inner tube, and the extension portions are arranged in an arc shape close to the surface of the inner tube.

[0015] In some embodiments, the annular groove is rectangular or sinusoidal in cross-section along the axial direction.

[0016] In some embodiments, there are multiple inner tubes, and there is a gap between two adjacent inner tubes, and the gap is filled with a gasket.

[0017] In some embodiments, the outer tube is made of aluminum alloy, and the inner tube is made of aluminum alloy or oxygen-free copper.

[0018] The present invention provides an over-molded corrugated waveguide capable of automatically performing mode optimization. Compared with the prior art, the present invention has the following advantages:

[0019] The inner tube is arranged in the outer tube at intervals, and the inner wall of the inner tube is provided with a plurality of annular grooves, and the plurality of annular grooves are distributed at intervals along the axial direction. The deformation body is arranged between the outer tube and the inner tube, and the plurality of the deformation bodies are distributed at intervals along the axial direction. The deformation body includes a plurality of memory alloy monomers arranged around the axial direction of the outer tube, and the memory alloy monomer includes a connecting portion and two deformation portions. The connecting portion is fixed to the inner wall of the outer tube, the first ends of the two deformation portions are connected to each other through the connecting portion, and the second ends of the two deformation portions abut against the outer wall of the inner tube. In this way, when the memory alloy monomer is heated, the second ends of the two deformation portions move closer to each other, so that the length of the memory alloy monomer in the radial direction becomes longer, causing the inner tube to produce a radial inward displacement; when the temperature of the memory alloy monomer decreases, the second ends of the two deformation portions separate from each other, so that the length of the memory alloy monomer in the radial direction becomes shorter, causing the inner tube to produce a radial outward displacement, and the radial displacement of the inner tube in turn affects the mode characteristics of the millimeter wave transmitted in the waveguide, and the above-mentioned displacement actively suppresses the HE 11 It can realize active correction and automatic mode optimization to achieve low-loss transmission of millimeter waves. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 A schematic diagram of the cross-sectional structure along the axial direction of an over-molded corrugated waveguide capable of automatically performing mode optimization is provided in some embodiments of the present invention.

[0021] Figure 2 A schematic diagram of an enlarged side view of a deformed body of an over-molded corrugated waveguide capable of automatically performing mode optimization, provided in some embodiments of the present invention.

[0022] Figure 3 A schematic diagram of the side-view magnified structure of a memory alloy monomer of an over-molded corrugated waveguide capable of automatically performing mode optimization at ambient temperature provided in some embodiments of the present invention.

[0023] Figure 4 A schematic side-view magnified structural diagram of a memory alloy monomer of an over-molded corrugated waveguide capable of automatically performing mode optimization after being heated, provided in some embodiments of the present invention.

[0024] Figure 5 A schematic diagram of an axial cross-sectional structure of an over-molded corrugated waveguide capable of automatically performing mode optimization, provided in some embodiments of the present invention, having two inner tubes.

[0025] In the figure: 1, outer tube; 2, inner tube; 21, annular groove; 22, gasket; 3, deformable body; 31, memory alloy monomer; 311, connecting part; 312, deformed part; 313, extension part; x, axial direction; z, radial direction. DETAILED DESCRIPTION

[0026] The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments.

[0027] It should be understood that in the description of this application, the terms "upper", "lower", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application. The terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated, that is, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In addition, unless otherwise specified, "multiple" means two or more.

[0028] In addition, the technical features involved in the different embodiments of the present application described below can be combined with each other as long as they do not conflict with each other.

[0029] like Figure 1-Figure 5As shown, some embodiments of the present invention include an overmolded corrugated waveguide capable of automatic mode optimization, comprising an outer tube 1, an inner tube 2, and a deformable body 3. The overmolded corrugated waveguide of the present invention can be used for long-distance millimeter-wave transmission, such as in nuclear fusion plasma heating, and particularly for millimeter-wave transmission over kilometers, as required in fields such as oil and gas drilling.

[0030] The inner tube 2 is spaced apart inside the outer tube 1 , and the inner wall of the inner tube 2 is provided with a plurality of annular grooves 21 , which are spaced apart along the axial direction x. In this way, the annular grooves 21 are provided to form an over-molded corrugated waveguide.

[0031] For example, the inner diameter of the inner tube 2 is a, and a=31.75 mm is selected. At this time, the waveguide transmission bandwidth is large, and millimeter waves of 105 GHz-170 GHz can be transmitted. λ is the wavelength of the millimeter wave.

[0032] d is the depth of the annular groove 21. When d=λ / 4, the transmission loss is low. When the center frequency is 140 GHz, d=0.54 mm.

[0033] h is the period length of two adjacent ring grooves 21, and satisfies h<0.5λ to avoid Bragg reflection. When h=0.65mm is selected, the maximum transmission frequency is 200 GHz.

[0034] w is the distance between two adjacent annular grooves 21 . If w / h is smaller, the ohmic loss is smaller. w=0.307*h=0.20 mm is selected to meet both the requirements of small ohmic loss and high mechanical strength.

[0035] e is the thickness of the inner tube 2 at the annular groove 21, and e = 1 mm. The inner wall of the inner tube 2 is formed by processes such as electrospark machining or precision milling, with a machining tolerance of less than ±0.02 mm. After machining, the coaxiality is verified using a three-dimensional coordinate measuring machine, and the coaxiality is ≤ 0.04 mm.

[0036] The deformable body 3 is arranged between the outer tube 1 and the inner tube 2. The multiple deformable bodies 3 are spaced apart along the axial direction x. The deformable body 3 includes multiple memory alloy monomers 31 arranged around the axial direction of the outer tube. The memory alloy monomer 31 includes a connecting portion 311 and two deformable portions 312. The connecting portion 311 is fixed to the inner wall of the outer tube 1. The first ends of the two deformable portions 312 are connected to each other through the connecting portion 311, and the second ends of the two deformable portions 312 abut against the outer wall of the inner tube 2.

[0037] For example, the memory alloy monomer 31 is made of Ni 50.7 Ti 49.3 The memory alloy material is made of memory alloy material, wherein the temperature range of restoring the initial shape is designed to be the ambient temperature (-10℃ to 40℃). In order to achieve automatic mode optimization, the memory alloy material selected has a two-way memory effect. The training process is: Ni 50.7 Ti49.3 The memory alloy material undergoes a solution treatment at 400°C for more than 1 hour and then an aging treatment at 450°C for 20 minutes.

[0038] In this embodiment, when the memory alloy monomer 31 is heated, the second ends of the two deformation parts 312 move closer to each other, causing the length of the memory alloy monomer 31 along the radial direction z to become longer, resulting in the inner tube 2 to produce a radial z inward displacement. When the temperature of the memory alloy monomer 31 decreases, the second ends of the two deformation parts 312 separate from each other, causing the length of the memory alloy monomer 31 along the radial direction z to become shorter, resulting in the inner tube to produce a radial z outward displacement.

[0039] Specifically, the memory alloy cell 31 is in its initial state at ambient temperature, with the two deformed portions 312 of the memory alloy cell 31 in an open state, shortening the length of the memory alloy cell 31 in the radial direction z. When the temperature rises, the second ends of the two deformed portions 312 move closer together, lengthening the length of the memory alloy cell 31 in the radial direction z. When the temperature drops to ambient temperature, the temperature of the memory alloy cell 31 decreases, causing the two deformed portions 312 of the memory alloy cell 31 to separate and open outward, shortening the memory alloy cell 31 and returning to its initial state.

[0040] It should be noted that the waveguide mode refers to the transverse electric field distribution pattern formed when electromagnetic waves propagate through the waveguide. Mode optimization, on the other hand, involves adjusting the waveguide's physical structural parameters (such as size, material, and position) to optimize signal transmission efficiency, reduce losses, or enhance specific performance indicators. In the present invention, waveguide mode optimization is achieved by adjusting the radial z position of the inner tube 2.

[0041] When the mode purity of the high-power millimeter wave in the waveguide decreases and a mixed mode is generated, the temperature distribution of the inner tube 2 and the outer tube 1 is uneven, and the memory alloy monomer 31 in the higher temperature area becomes longer, pushing the inner tube 2 to move along the radial direction z, guiding the waveguide to optimize the mode; when the mode purity of the high-power millimeter wave in the waveguide is close to 100%, such as Figure 3 As shown, the deformable body 3 is subjected to uniform force in the circumferential direction, and the inner tube 2 maintains its initial center position, which does not affect the mode of the waveguide.

[0042] During operation, the inner tube 2 has surface impedance. High-power millimeter waves will cause the temperature of the inner tube 2 to increase, and the local current density will surge due to the heterogeneous mode, which will increase the hot spot temperature of the inner tube 2 (the temperature can increase by more than 30°C). The temperature increase causes the shape memory alloy monomer 31 to deform. In this example, the maximum radial z displacement of the inner tube 2 is δr = 0.16mm, and the radial z length f of the shape memory alloy monomer 31 is f min = 2.4mm and f max = 2.56mm. The deformation of the shape memory alloy monomer 31 causes the inner tube 2 to move inward along the radial z direction. The radial z movement of the inner tube 2 in turn affects the mode characteristics of the millimeter wave transmitted in the waveguide. The heterogeneous mode is actively suppressed through the radial z movement, and the mode is automatically optimized. The optimization process is as follows:

[0043] The radial z movement of the inner tube 2 changes the equivalent impedance of the annular groove 21, thereby reducing the propagation constant of the heterogeneous mode.

[0044] Negative feedback is generated: more stray modes lead to thermal imbalance, which causes the memory alloy monomer 31 to deform. The deformation of the memory alloy monomer 31 causes the inner tube 2 to move in the radial direction z, and the radial z movement of the inner tube reduces the stray modes.

[0045] Based on the above-mentioned structural setting, when the memory alloy monomer 31 is heated, the second ends of the two deformed parts 312 move closer to each other, causing the length of the memory alloy monomer 31 along the radial direction z to increase, resulting in a radial z displacement of the inner tube 2. The radial z displacement of the inner tube 2 in turn affects the mode characteristics of the millimeter wave transmitted in the waveguide, realizing active correction and automatic optimization of the mode, and achieving low-loss transmission of the millimeter wave.

[0046] In some embodiments, the wall of the outer tube 1 has a water-cooling channel, and the water-cooling channel has a water inlet and a water outlet. Specifically, the radial z thickness of the outer tube 1 is 5 mm. The channel type is a spiral water-cooling channel, and the water inlet and the water outlet are fixed to the water pipe with clamps, and the outer diameter of the interface of the water inlet and the water outlet is 11.7 mm. The cooling water flow rate is ≥6L / min. While ensuring that the water pressure is less than 0.4MPa, multiple sections of waveguides can be connected in series to the water cooling pipeline. Deionized water is required for cooling water, with a resistivity greater than 1MΩ*cm and dissolved oxygen less than 500ppb.

[0047] In some embodiments, the memory alloy monomer 31 is a nickel-titanium-based shape memory alloy, a copper-based shape memory alloy, or an iron-based shape memory alloy. For example, the nickel-titanium-based shape memory alloy has a recoverable strain performance of more than 10%, high damping characteristics, smooth deformation process, wear resistance and corrosion resistance, and a resistivity of 8×10 -7Ω·m, suitable for use in high-power millimeter-wave over-molded corrugated circular waveguides. It should be noted that shape memory materials, in addition to shape memory alloys, also include shape memory polymers and shape memory ceramics. However, these two materials cannot constrain millimeter waves, and the deformation caused by heating has little effect on millimeter waves, making it difficult to achieve automatic mode optimization.

[0048] In some embodiments, the surface of the memory alloy unit 31 has a nickel plating layer. The nickel plating layer is preferably 3 μm thick, which can improve the wear resistance of the memory alloy unit 31.

[0049] like Figure 3 and 4 As shown, in some embodiments, the connecting portion 311 and the deforming portion 312 are integrally formed. During the forming process, heat treatment is required under vacuum or argon protection, otherwise surface oxidation will change the nickel-titanium ratio and cause phase transition temperature drift.

[0050] like Figure 3 and 4 As shown, in some embodiments, the connecting portion 311 is provided in a radial z-arc-shaped projection, thereby avoiding stress concentration between the two deforming portions 312 and extending the service life.

[0051] like Figure 3 and 4 As shown, in some embodiments, the second end of the deformable portion 312 has an extension portion 313. The extension portions 313 of the two deformable portions 312 are spaced apart from each other, and the extension portions 313 abut against the outer wall of the inner tube 2. The extension portions 313 are arranged in an arc shape near the surface of the inner tube 2. In this way, during the deformation process, the frictional resistance of the extension portion 313 moving on the outer wall of the inner tube 2 is relatively small, which facilitates the radial z movement of the inner tube 2.

[0052] In some embodiments, the annular groove 21 has a rectangular or sinusoidal cross-section along the axial x-plane.

[0053] like Figure 5 As shown, in some embodiments, multiple inner tubes 2 are provided, with gaps between adjacent inner tubes 2 filled with gaskets 22. Specifically, when the axial x-length of the outer tube 1 is greater than 0.5 m, the inner tubes 2 need to be divided into equal intervals. The smaller the axial x-interval, the better the waveguide optimization effect. The gap between adjacent inner tubes is less than 1 mm and filled with polytetrafluoroethylene gaskets to reduce millimeter wave leakage.

[0054] In some embodiments, the outer tube 1 is made of aluminum alloy, and the inner tube 2 is made of aluminum alloy or oxygen-free copper.

[0055] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and substitutions can be made without departing from the technical principles of the present invention. These improvements and substitutions should also be regarded as the scope of protection of the present invention.

Claims

1. An overmolded corrugated waveguide capable of automatic mode optimization, characterized in that: include: External control; an inner tube, spaced apart inside the outer tube, wherein the inner wall of the inner tube is provided with a plurality of annular grooves, wherein the plurality of annular grooves are spaced apart along the axial direction; and a deformable body disposed between the outer tube and the inner tube, wherein the plurality of deformable bodies are spaced apart along the axial direction, the deformable body comprising a plurality of memory alloy monomers disposed axially around the outer tube, the memory alloy monomers comprising a connecting portion and two deformable portions, the connecting portion being fixed to the inner wall of the outer tube, the first ends of the two deformable portions being connected to each other via the connecting portion, and the second ends of the two deformable portions being in contact with the outer wall of the inner tube; Among them, when the memory alloy monomer is heated, the second ends of the two deformed parts move closer to each other, so that the radial length of the memory alloy monomer becomes longer, causing the inner tube to move radially inward; when the temperature of the memory alloy monomer decreases, the second ends of the two deformed parts separate from each other, so that the radial length of the memory alloy monomer becomes shorter, causing the inner tube to move radially outward.

2. The overmolded corrugated waveguide capable of automatic mode optimization according to claim 1, characterized in that The tube wall of the outer tube is provided with a water cooling channel, and the water cooling channel has a water inlet and a water outlet.

3. The overmolded corrugated waveguide capable of automatic mode optimization according to claim 1, wherein: The memory alloy monomer is a nickel-titanium-based shape memory alloy, a copper-based shape memory alloy or an iron-based shape memory alloy.

4. The overmolded corrugated waveguide capable of automatic mode optimization according to claim 1, wherein: The surface of the memory alloy monomer is provided with a nickel plating layer.

5. The overmolded corrugated waveguide capable of automatic mode optimization according to claim 1, wherein: The connecting portion and the deforming portion are integrally formed.

6. The overmolded corrugated waveguide capable of automatic mode optimization according to claim 5, characterized in that The connecting portion is provided in a radial arc-shaped protrusion.

7. The overmolded corrugated waveguide capable of automatic mode optimization according to claim 1, wherein: The second end of the deformation portion has an extension portion, the extension portions of the two deformation portions are away from each other, the extension portions abut against the outer wall of the inner tube, and the extension portions are arranged in an arc shape close to the surface of the inner tube.

8. The overmolded corrugated waveguide capable of automatic mode optimization according to claim 1, wherein: The annular groove is rectangular or sinusoidal in cross section along the axial direction.

9. The overmolded corrugated waveguide capable of automatic mode optimization according to claim 1, wherein: There are multiple inner tubes, and there is a gap between two adjacent inner tubes. The gap is filled with a gasket.

10. The overmolded corrugated waveguide capable of automatically performing mode optimization according to any one of claims 1 to 9, characterized in that: The outer tube is made of aluminum alloy, and the inner tube is made of aluminum alloy or oxygen-free copper.

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