Slow wave structure, traveling wave tube and communication device

Abstract

A slow wave structure, a traveling wave tube and a communication device, the slow wave structure comprises a tube shell, a slow wave line and a plurality of support parts, the slow wave line and the plurality of support parts are located in the tube shell, and the tube shell, the slow wave line and the plurality of support parts are connected into a whole; the plurality of supporting parts are sequentially distributed at intervals along the slow wave line; one end of each supporting part is connected with the tube shell, and the other end is connected with the slow-wave line. According to the invention, processing and assembling errors caused by a split type design can be improved, and assembling is simplified, so that the overall production period of the traveling wave tube is shortened, and the yield and consistency of the traveling wave tube are improved.

Description

Slow-wave structure, traveling wave tube and communication device Technical Field

[0001] The present application relates to the field of communication equipment, and in particular to a slow-wave structure, a traveling wave tube, and a communication device. Background Art

[0002] Traveling-wave tubes (TWTs), a type of power amplifier currently commonly used in the millimeter-wave frequency band, offer the combined advantages of a wide operating bandwidth, high output power, high efficiency, and compact size, holding broad application prospects in millimeter-wave communications. The core component of a TWT is the slow-wave structure. Conventional slow-wave structures are complex to assemble, resulting in long TWT production cycles, low yields, and poor consistency.

[0003] Summary of the Invention

[0004] The technical solution of the present application provides a slow-wave structure, a traveling wave tube, and a communication device, which can simplify the assembly of the slow-wave structure, shorten the overall production cycle of the traveling wave tube, and improve the yield and consistency of the traveling wave tube.

[0005] In the first aspect, the technical solution of the present application provides a slow-wave structure, including a tube shell, a slow-wave line and multiple support parts, the slow-wave line and the multiple support parts are all located inside the tube shell, and the tube shell, the slow-wave line and the multiple support parts are connected as a whole; the multiple support parts are distributed in sequence along the slow-wave line; one end of each support part is connected to the tube shell, and the other end is connected to the slow-wave line.

[0006] This solution integrates the tube housing, slow-wave line, and support components into a single unit. This reduces the processing and assembly errors associated with conventional split-piece designs, simplifies the assembly process, shortens the overall production cycle, and improves the yield and consistency of traveling wave tubes. By suspending the slow-wave line within the tube housing via multiple support components, a novel slow-wave structure is provided that meets product requirements.

[0007] In an implementation of the first aspect, the tube shell includes a tube shell body and multiple tube shell protrusions, the multiple tube shell protrusions are all connected to the tube shell body, the multiple tube shell protrusions are all protruded relative to the tube shell body, and the multiple tube shell protrusions are distributed in sequence along the tube shell body; the slow wave line is located in the tube shell body; a portion of each support portion is accommodated in the tube shell body, and another portion of each support portion is accommodated in the tube shell protrusion.

[0008] In this solution, by configuring the shell to be a shell body and a shell convex portion, and positioning the support portion inside the shell body and the shell convex portion, the product design requirements for a larger volume slow-wave structure can be met, and by making the support portion longer, the support strength of the support portion can be increased.

[0009] In one implementation of the first aspect, the length direction of at least one support portion is perpendicular to the length direction of the slow-wave line. By making the length direction of the support portion perpendicular to the length direction of the slow-wave line, the slow-wave structure is compact and has high structural strength, which is also conducive to miniaturization of the product.

[0010] In one implementation of the first aspect, the length direction of at least one support portion forms a non-90-degree angle with the length direction of the slow-wave line. By tilting the support portion relative to the slow-wave line, the support portion can be sufficiently long within a limited space, thereby ensuring the support strength of the support portion.

[0011] In an implementation of the first aspect, at least some of the plurality of support portions are sequentially connected to form a wavy line structure. By connecting the support portions to form a wavy line structure, the structural strength and support strength can be increased.

[0012] In an implementation of the first aspect, the plurality of support portions are respectively distributed on both sides of the slow-wave line. Distributing the support portions on opposite sides of the slow-wave line is beneficial for ensuring structural strength and support strength.

[0013] In an implementation of the first aspect, the length L of each support portion and the waveguide wavelength λ of the slow-wave structure satisfy the following relationship: n is an odd number. By ensuring that the length of the support portion satisfies the above relationship, product requirements can be met. In particular, when the support portion is made of a conductive material, impedance matching facilitates ensuring that the apparent impedance of high-frequency electromagnetic waves from the slow-wave line to the tube housing is an open circuit, ensuring that the support portion does not affect signal transmission within the operating frequency band.

[0014] In one implementation of the first aspect, the tube housing, the slow-wave line, and the multiple support portions are made of the same material. Using the same material facilitates the manufacture of an integrated slow-wave structure through a planarization process, simplifies assembly of the slow-wave structure, shortens the overall production cycle of the traveling wave tube, and improves the yield and consistency of the traveling wave tube.

[0015] In one implementation of the first aspect, each support portion includes an inner layer and an outer layer, the outer layer wrapping around the inner layer; the inner layer is made of an insulating material, and the outer layer is made of the same material as the tube housing and the slow-wave line. By making the outer layer of the support portion the same material as the tube housing and the slow-wave line, the slow-wave structure can be manufactured using a 3D printing process, simplifying its assembly, shortening the overall production cycle of the traveling wave tube, and improving the yield and consistency of the traveling wave tube.

[0016] In one implementation of the first aspect, the slow-wave structure further includes an attenuator, and the slow-wave line includes multiple, unconnected segments, each of which is connected to an attenuator. By dividing the slow-wave line and providing the attenuators, reflected electromagnetic waves can be absorbed, parasitic oscillations in the traveling wave tube can be prevented, and the gain and stability of the traveling wave tube can be improved.

[0017] In one implementation of the first aspect, the slow-wave line is a fold line, which includes a plurality of bending units connected end to end, and all the bending units are coplanar. By applying the above-mentioned integrated design to the slow-wave structure having a fold line, the assembly of the slow-wave structure can be simplified.

[0018] In one implementation of the first aspect, the plurality of support portions are coplanar with the slow-wave line. This coplanarity facilitates the use of a planarization process to manufacture the slow-wave structure, simplifies assembly of the slow-wave structure, shortens the overall production cycle of the traveling wave tube, and improves the yield and consistency of the traveling wave tube.

[0019] In one implementation of the first aspect, the slow-wave structure includes two layers of support portions with a gap between them, each layer of support portions including multiple support portions; the slow-wave structure includes two layers of slow-wave wires with a gap between them, with each layer of slow-wave wires correspondingly connected to each layer of support portions. The slow-wave structure with two layers of slow-wave wires has a stronger electromagnetic wave field, stronger interaction, and higher efficiency and gain. By applying the aforementioned integrated design to the slow-wave structure with two layers of slow-wave wires, assembly of the slow-wave structure can be simplified.

[0020] In an implementation of the first aspect, the slow-wave line has a helical structure. By applying the above-mentioned integrated design to the slow-wave structure having a helical structure, the assembly of the slow-wave structure can be simplified.

[0021] In the second aspect, the technical solution of the present application provides a traveling wave tube, including an electron gun, a focusing system, a collector, an input device, an output device and a slow-wave structure of any of the above items, and the electron gun, focusing system, collector, input device and output device are all connected to the slow-wave structure.

[0022] The slow-wave structure in this solution has an integrated structure, and its assembly is relatively simple, which shortens the overall production cycle of the traveling wave tube and increases the yield and consistency of the traveling wave tube.

[0023] In one implementation of the second aspect, the input device and / or the output device includes a mode converter, which is connected to the slow-wave line and configured to convert between an operating mode of the slow-wave structure and an operating mode of the external circuit. By providing the mode converter, matching between the slow-wave structure and the external circuit can be achieved.

[0024] In an implementation of the second aspect, the slow-wave structure includes two layers of slow-wave lines; the mode converter includes a flat waveguide, a conductive plate, a ridge and a coupled stripline; the conductive plate is arranged in the inner cavity of the flat waveguide, and the plate surfaces on opposite sides of the conductive plate and the cavity wall of the inner cavity have gaps; the ridge is arranged on the plate surface, and the ridge is not connected to the cavity wall of the inner cavity; the inner conductor of the coupled stripline includes a first part and a second part, the first part connects the ridge and the second part, and the end of the second part facing away from the first part is connected to the two layers of slow-wave lines; the width of the first part is greater than the width of the second part, and the width of the first part tends to decrease along the direction from the first part to the second part.

[0025] In this solution, for the slow-wave structure with double-layer folded lines, by designing the above-mentioned mode converter, the conversion between the external circuit mode and the slow-wave structure mode can be achieved, thereby achieving good matching between the slow-wave structure and the external circuit.

[0026] In an implementation of the second aspect, the slow-wave structure includes two layers of slow-wave lines; the mode converter includes a flat waveguide, a ridge and a coupled stripline; the ridge is arranged in the inner cavity of the flat waveguide, the ridge includes a first surface and a second surface, the first surface is opposite to the second surface, and the distance between the first surface and the second surface tends to decrease from one end of the ridge to the other opposite end, there is a gap between the first surface and the inner wall of the inner cavity, and the second surface is connected to the inner wall of the inner cavity; the inner conductor of the coupled stripline connects the ridge and the two layers of slow-wave lines.

[0027] In this solution, for a slow-wave structure with double-layer folded lines, the aforementioned mode converter is designed to achieve conversion between the external circuit mode and the slow-wave structure mode, achieving a good match between the slow-wave structure and the external circuit. The mode converter structure of this solution is relatively simple and can meet product requirements.

[0028] In one implementation of the second aspect, the first surface has a plurality of steps connected in sequence, with the heights of the steps decreasing sequentially. By designing the first surface of the ridge into a stepped structure, the ridge can achieve bidirectional mode conversion and impedance matching, meeting product requirements.

[0029] In one implementation of the second aspect, the mode converter includes a tapered waveguide and a standard rectangular waveguide, the tapered waveguide connecting the flat waveguide and the standard rectangular waveguide, and the coupled stripline and the standard rectangular waveguide located at opposite ends of the flat waveguide. By designing the tapered waveguide and the standard rectangular waveguide, the mode converter can convert between a standard waveguide mode of an external circuit and a mode of the slow-wave structure.

[0030] In a third aspect, the technical solution of the present application provides a communication device comprising any of the above-mentioned traveling wave tubes. The slow-wave structure in this solution has an integrated structure, which is relatively simple to assemble, thereby shortening the overall production cycle of the communication device and improving the yield and consistency.

[0031] In one implementation of the third aspect, the communication device is a network device, a terminal device, a vehicle-mounted device, or a satellite payload. This solution can be applied in scenarios such as network devices, terminal devices, vehicle-mounted devices, or satellite payloads to meet design requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] FIG1 is a schematic diagram of the framework structure of a traveling wave tube according to an embodiment of the present application;

[0033] FIG2 is a schematic diagram of the external structure of the slow-wave structure in Example 1;

[0034] FIG3 is a schematic diagram of the internal and external structures of the slow-wave structure in Example 1;

[0035] FIG4 is a schematic structural diagram of a slow-wave line and a supporting portion of a slow-wave structure in Example 1;

[0036] FIG5 shows a transmission characteristic curve of the slow-wave structure in Example 1;

[0037] FIG6 shows a simulation result of an injection-wave interaction of the slow-wave structure in Example 1;

[0038] FIG7 shows another beam-wave interaction simulation result of the slow-wave structure in Example 1;

[0039] FIG8 is a schematic diagram of the internal and external structures of the mode converter in implementation mode 1 of embodiment 1;

[0040] FIG9 is a schematic AA cross-sectional view of the mode converter shown in FIG8 ;

[0041] FIG10 is a schematic diagram of a partial structure of the mode converter shown in FIG8 ;

[0042] FIG11 is a B-direction view of the structure shown in FIG10;

[0043] FIG12 shows the transmission performance simulation results of the traveling wave tube after using the mode converter;

[0044] FIG13 is a schematic diagram of the internal and external structures of the mode converter in implementation mode 2 of embodiment 1;

[0045] FIG14 is a schematic side view of the ridge structure of the mode converter in another implementation manner of Example 1;

[0046] FIG15 is a schematic diagram of the external structure of the slow-wave structure in Example 2;

[0047] FIG16 is a schematic diagram of the internal and external structures of the slow-wave structure in Example 2;

[0048] FIG17 is a schematic diagram of the internal and external structures of the slow-wave structure in Example 3;

[0049] 18 is a schematic structural diagram of the slow-wave line and the support portion of the slow-wave structure in Example 3;

[0050] FIG19 is a schematic diagram of the external structure of the slow-wave structure in Example 4;

[0051] FIG20 is a schematic diagram of the internal and external structures of the slow-wave structure in Example 4;

[0052] 21 is a schematic structural diagram of the slow-wave line and the support portion of the slow-wave structure in Example 4;

[0053] FIG22 is a schematic diagram of a slow-wave structure according to an embodiment of the present application;

[0054] FIG23 shows a schematic layered slice of a slow-wave structure according to an embodiment of the present application;

[0055] FIG24 is a schematic diagram showing the regional allocation of a substrate;

[0056] FIG25 is a schematic diagram of a slow-wave structure array electroplated on a copper wafer;

[0057] FIG26 is a schematic diagram showing a slow-wave structure having a double-layer folding line assembled from a slow-wave structure unit manufactured by a planarization process and an outer shell. DETAILED DESCRIPTION

[0058] In the embodiments of this application, the terms "first," "second," "third," etc., are used solely to distinguish components and should not be construed as indicating or implying the relative importance of the components or implicitly specifying the number of the technical features indicated. Therefore, a feature defined as "first," "second," etc., may explicitly or implicitly include one or more of the features.

[0059] In the description of the embodiments of the present application, unless otherwise specified, “multiple (layers)” means two (layers) or more than two (layers).

[0060] In the embodiments of the present application, terms such as "upper", "lower", "front", "front side", "back", and "rear" are defined relative to the orientation of the structure schematically placed in the accompanying drawings. It should be understood that these directional terms are relative concepts. They are a relative description and clarification, which can change accordingly according to the change of the orientation of the structure.

[0061] In the embodiments of the present application, unless otherwise specified, "and / or" is merely a description of the association relationship between associated objects, indicating that three relationships can exist. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone.

[0062] The following embodiments of the present application provide a communication device that can be used in both low-frequency scenarios (sub 6G) and high-frequency scenarios (above 6G). Application scenarios include, but are not limited to, Long Term Evolution (LTE) systems, fifth-generation systems, new radio (NR) communication systems, or future evolved public land mobile network (PLMN) systems. The communication device includes, but is not limited to, network equipment, terminal equipment, vehicle-mounted equipment, satellite payloads, and the like.

[0063] The network equipment includes, but is not limited to, the next generation base station (g nodeB, gNB) in 5G, the evolved node B (eNB) in the long term evolution (LTE) system, the radio network controller (RNC), the radio controller in the cloud radio access network (CRAN) system, the base station controller (BSC), the home base station (for example, home evolved nodeB, or home nodeB, HNB), the baseband unit (BBU), the transmission point (TRP), the transmitting point (TP), the mobile switching center, the base transceiver station (BTS) in the global system for mobile communication (GSM) or code division multiple access (CDMA) network, and the node base station (BTS) in the wideband code division multiple access (WCDMA) network. It can be a base station (NB), an evolved NB (eNB or eNodeB) in LTE, a base station device in a future 5G network or an access network device in a future evolved PLMN network, a wearable device or a vehicle-mounted device, a radio frequency base station, a microwave base station, a millimeter wave base station, a terahertz base station, etc.

[0064] When the network device is an access network device, the network device can also be connected to a core network (CN) device. Among them, the access network device refers to a device that provides network access functions, such as a radio access network (RAN), a base station, and the like. The network device may specifically include a base station (BS) (such as a RAN base station), or a base station and a wireless resource management device for controlling the base station. The network device may also include a relay station (relay device), an access point, a base station in a future 5G network, a base station in a future evolved PLMN network, or an NR base station. The network device may be a wearable device or an in-vehicle device. The network device may also be a communication chip with a communication module.

[0065] The terminal device may be user equipment (UE), terminal, access terminal, terminal unit, terminal station, mobile station (MS), remote station, remote terminal, mobile terminal, wireless communication device, terminal agent, etc. The terminal device may have wireless transceiver capabilities, and may communicate (e.g., wirelessly) with one or more network devices of one or more communication systems and receive network services provided by the network devices. The terminal device may be a cellular phone, a cordless phone, a Session Initiation Protocol (SIP) phone, a wireless local loop (WLL) station, a personal digital assistant (PDA) device, a handheld device with wireless communication capabilities, a computing device or other processing device connected to a wireless modem, an in-vehicle device, a wearable device, a terminal device in a future 5G network, or a terminal device in a future evolved PLMN network, etc.

[0066] Terminal devices can be deployed on land, including indoors or outdoors, handheld or vehicle-mounted; they can also be deployed on water (such as ships); and they can also be deployed in the air (such as on airplanes, balloons, and satellites). The terminal devices can specifically be mobile phones, tablets, computers with wireless transceiver functions, monitors, virtual reality (VR) terminals, augmented reality (AR) terminals, wearable devices (such as smart watches and smart bracelets), smart screen devices, headphones (such as wired headphones and wireless headphones), routers, portable Wi-Fi, mobile power supplies, e-readers, mice, smart speakers, printers, smart door locks, home storage, wireless terminals in industrial control, wireless terminals in self-driving cars, wireless terminals in remote medical care, wireless terminals in smart grids, wireless terminals in transportation safety, wireless terminals in smart cities, and wireless terminals in smart homes. The terminal device may also be a communication chip with a communication module, or a vehicle with communication functions, or an on-board device (such as an on-board communication device, an on-board communication chip), etc.

[0067] On-board equipment includes but is not limited to millimeter-wave radar, terahertz imaging equipment, etc.

[0068] Satellite payload refers to the instruments, equipment or systems carried on satellites to perform specific tasks. Such satellites include but are not limited to communication satellites, meteorological satellites, etc.

[0069] The communication device of the embodiments of the present application utilizes a traveling wave tube (TWT). As an electric vacuum power amplifier device, TWTs offer the combined advantages of wide operating frequency bandwidth, high output power, high efficiency, and compact size, and have broad application prospects in millimeter wave communications. For example, in millimeter wave base station applications, the use of millimeter wave TWTs can significantly increase the base station's equivalent isotropically radiated power (EIRP), thereby reducing the number of base stations and saving deployment costs.

[0070] FIG1 shows a schematic structure of a traveling wave tube according to an embodiment of the present application. As shown in FIG1 , the traveling wave tube 1 may include a slow-wave structure 14 (the portion between two dashed lines), an electron gun 11, a collector 15, a focusing system 13 (the dotted shaded area), an input device 12, and an output device 16. The slow-wave structure 14 may include a tube housing and a slow-wave line suspended within the tube housing (described below).

[0071] The electron gun 11 and collector 15 can be connected to opposite ends of the slow-wave structure 14. As shown in Figure 1, the focusing system 13 can, for example, surround the outer periphery of the tube shell of the slow-wave structure 14. In other embodiments, the focusing system 13 can also be distributed on both sides of the tube shell of the slow-wave structure 14. The input device 12 and the output device 16 are respectively connected to the ends of the slow-wave structure 14. The input device 12 and the output device 16 can accommodate the slow-wave structure 14 and provide a vacuum working environment for the slow-wave structure 14. The input device 12 and the output device 16 are both connected to the slow-wave line.

[0072] As shown in FIG1 , the operating principle of the traveling wave tube 1 is as follows: an electron gun 11 generates an electron beam and accelerates it to a speed slightly faster than the electromagnetic wave traveling along the slow-wave line. The electron beam emitted by the electron gun 11 can enter the slow-wave structure 14 and propagate along the slow-wave line. A focusing system 13 can maintain the desired shape of the electron beam, ensuring that the electron beam smoothly passes through the slow-wave structure 14 and effectively interacts with the electromagnetic field. The focusing system 13 can, for example, be a magnetic focusing system that confines the electron beam through a magnetic field. An input device 12 can be connected to an external circuit and input the signal to be amplified from the external circuit into the slow-wave structure 14. The input device 12 can also perform mode conversion on the signal to be amplified, for example, converting the waveguide mode of the signal to be amplified into a transverse electromagnetic mode (TEM) or a quasi-TEM mode, so that the operating mode of the slow-wave structure 14 matches the mode of the external signal. The slow-wave structure 14 is the core component of the traveling wave tube 1, enabling the electron beam to fully interact with the signal to be amplified, converting the kinetic energy of the electrons into electromagnetic wave energy, thereby achieving signal amplification. When the electron beam interacts with the electromagnetic wave, it is also modulated by the electromagnetic wave. The amplified signal can be transmitted by the slow-wave line to the output device 16 and coupled to the external circuit through the output device 16. The output device 16 can perform mode conversion on the amplified signal, for example, converting the TEM mode or quasi-TEM mode of the amplified signal into a waveguide mode, so that the output signal of the traveling wave tube 1 matches the mode of the external signal. The collector 15 is used to collect the electron beam remaining after the interaction with the slow-wave structure 14.

[0073] Most or all of the components of the slow-wave structure 14 of the embodiment of the present application are integrated into one structure. That is, most or all of the components of the slow-wave structure 14 can be manufactured in the same process (a semiconductor process or a planarization process such as a 3D printing process described below) to form an integrated structure. This will be described in detail below.

[0074] 2 and 3 show schematic structures of the slow-wave structure 14 of the first embodiment, wherein FIG. 2 is a schematic diagram of the external structure of the slow-wave structure 14 , and FIG. 3 is a schematic diagram of the internal structure of the slow-wave structure 14 .

[0075] As shown in Figures 2 and 3, the slow-wave structure 14 can include a tube shell 141, two layers of slow-wave lines 142, and multiple support portions 143. The tube shell 141, the two layers of slow-wave lines 142, and the multiple support portions 143 are connected as a whole. The tube shell 141 has a cavity inside, and the two layers of slow-wave lines 142 and the multiple support portions 143 are all accommodated in the cavity of the tube shell 141.

[0076] In this embodiment, the housing 141 can be a one-piece structure, which can be manufactured using the planarization process. Alternatively, the housing 141 can be assembled from multiple sub-housings, and the housing 141 as a whole can be a split structure, but at least one of the sub-housings can be a one-piece structure manufactured using the planarization process. It is understood that for the housing 141 as a whole having a split structure, the slow-wave line 142 and the support portion 143 can be integrated with the sub-housings in the split housing 141, which can also be referred to as the housing 141, slow-wave line 142, and support portion 143 remaining integrated.

[0077] As shown in Figures 2 and 3, the shell 141 may include a shell body 141a, multiple shell protrusions 141b, and two shell protrusions 141c. The shell body 141a may be, for example, in the shape of a long rectangular box. The shell protrusions 141b and 141c may be, for example, in the shape of a short rectangular box. The shell protrusions 141b and 141c are both connected to the outside of the shell body 141a and both protrude relative to the surface of the shell body 141a. Multiple shell protrusions 141b may be arranged on opposite sides of the shell body 141a (for example, on both sides of the two opposite long sides of the shell body 141a). There is a certain distance between two adjacent shell protrusions 141b. The distance between any two adjacent shell protrusions 141b may be substantially equal or equal. The two housing protrusions 141c can be located at opposite ends of the housing body 141a. Schematically, the two housing protrusions 141c can be located on opposite sides of the housing body 141a. The housing body 141a, the housing protrusions 141b, and the housing protrusions 141c are all hollow, and together they form the inner cavity of the housing 141. It should be understood that the above-described external structure of the housing 141 is merely an example; in practice, the external structure of the housing 141 can be designed as needed.

[0078] As shown in Figure 3 , two layers of slow-wave lines 142 can be suspended within the housing body 141a , without contacting the inner wall of the housing body 141a . As shown in Figures 3 and 4 , the two layers of slow-wave lines 142 can be stacked along the thickness direction H in Figure 3 , with a gap between the two layers of slow-wave lines 142 . The structures of the two layers of slow-wave lines 142 can be identical or nearly identical, and when projected along the thickness direction H, the two layers of slow-wave lines 142 can overlap or nearly overlap.

[0079] As shown in FIG4 , the slow-wave line 142 can be a folded line. The slow-wave line 142 is composed of a plurality of bending units 142a connected end to end. The bending units 142a can be approximately "n" or "u" shaped, for example. In some embodiments, the bending units 142a can also have other suitable shapes, such as "v" shape, "s" shape, etc. The various parts of each bending unit 142a can be on the same plane, and all the bending units 142a can also be coplanar, so that the slow-wave line 142 is distributed on the same plane. The number of the bending units 142a can be designed as needed. For example, the number of the bending units 142a can be 75, or the number of periods of the slow-wave line 142 is 75.

[0080] As shown in FIG4 , the slow-wave line 142 can be strip-shaped as a whole, and a length direction L1 of the strip-shaped slow-wave line 142 can be defined, that is, the direction in which the slow-wave line 142 extends from one end (e.g., the left end in FIG4 ) to the other end (e.g., the right end in FIG4 ). Schematically, the length direction L1 can be the horizontal direction in FIG4 .

[0081] Figures 3 and 4 also illustrate two input lines 121 in the input device 12 and two output lines 161 in the output device 16. The two input lines 121 and the two output lines 161 can be connected to the ends of the slow-wave line 142 in the length direction L1, respectively. One input line 121 is connected to one layer of slow-wave line 142, and one output line 161 is connected to one layer of slow-wave line 142. The structure and type of the input lines 121 and the output lines 161 are not limited. For example, the input lines 121 and the output lines 161 can both be inner conductors in a coupled stripline. The input device 12 can input a signal to be amplified into the slow-wave line 142 via the input lines 121. The output device 16 can output the amplified signal via the output lines 161. The input lines 121 and the output lines 161 can each extend into the two housing protrusions 141c.

[0082] As shown in Figures 3 and 4, all support portions 143 can also be divided into two layers arranged at intervals. The two layers can be stacked along the thickness direction H in Figure 3. When projected along the thickness direction H, the two layers of support portions 143 can overlap or approximately overlap. There is a gap between the corresponding two support portions 143 in the two layers. In each layer, the support portion 143 can be coplanar or approximately coplanar with the slow-wave line 142. The support portions 143 can be distributed in sequence along the length direction L1 of the slow-wave line 142. Multiple support portions 143 can be distributed on both sides of the slow-wave line 142. The number and spacing of the support portions 143 can be designed according to product requirements. For example, adjacent support portions 143 can be spaced apart by 7 bending units 142a, or by 7 periods of the slow-wave line 142.

[0083] As shown in FIG4 , the support portion 143 can be roughly strip-shaped or rod-shaped (for example, the support portion 143 can be referred to as a branch), and a length direction L2 of the support portion 143 can be defined. Schematically, the length direction L2 can be the vertical direction in FIG4 , and the length direction L2 can be perpendicular or approximately perpendicular to the length direction L1 of the slow-wave line 142. Schematically, the lengths (dimensions along the length direction L2) of all support portions 143 can be consistent or approximately consistent.

[0084] As shown in Figures 4 and 3 , a portion of support portion 143 can be located within housing body 141a, while another portion can be located within housing protrusion 141b. Support portion 143 is connected between the inner wall of housing protrusion 141b and slow-wave line 142. Support portion 143 supports slow-wave line 142, allowing slow-wave line 142 to be suspended within housing 141 via support portion 143. By distributing support portion 143 within housing body 141a and housing protrusion 141b, the length of support portion 143 can be tailored to meet product requirements and enhance support strength.

[0085] In this embodiment, the support portion 143, slow-wave line 142, and housing 141 can be made of the same conductive material, with all parts of the support portion 143 made of the same conductive material. The conductive material can be a metal, such as a molybdenum alloy, a tungsten alloy, tungsten, molybdenum, copper, stainless steel, or a nickel-based alloy. The conductive material can also be a non-metallic material. Using the same conductive material facilitates mass production of the slow-wave structure 14 using a planarization process.

[0086] In another embodiment, the support portion 143 may include an inner layer and an outer layer, with the outer layer covering the outer surface of the inner layer and enclosing all areas of the inner layer. The inner layer may be made of an insulating material. The outer layer may be made of the same conductive material as the slow-wave line 142 and the housing 141. The slow-wave structure of this embodiment may be manufactured using, for example, a 3D printing process.

[0087] In another embodiment, the materials of the support portion 143 , the slow-wave line 142 and the tube shell 141 may not be all the same. The support portion 143 may be made of conductive material or insulating material, and the slow-wave line 142 and the tube shell 141 may be made of conductive material.

[0088] In this embodiment, the support portion 143 may be made of a conductive material, and the length L of the support portion 143 and the waveguide wavelength λ of the slow-wave structure 14 may satisfy the following relationship: n is an odd number. It is understood that n is a positive number, for example, n can be 1, 3 or 5. The 10% in this relationship represents the error range. For example, the length L of the support portion 143 can be wait.

[0089] Because support portion 143 connects slow-wave line 142 to housing 141, from a DC perspective, support portion 143 directly grounds slow-wave line 142 (housing housing 141 as the ground). The aforementioned length design of support portion 143 facilitates impedance matching, ensuring that the apparent impedance of high-frequency electromagnetic waves from slow-wave line 142 to housing 141 is an open circuit, ensuring that support portion 143 does not affect signal transmission within the operating frequency band.

[0090] In other embodiments, at least a portion of the support portion 143 may be made of insulating material, for example, the inner layer of the support portion 143 may be made of insulating material and the outer layer may be made of conductive material; or all portions of the support portion 143 may be made of insulating material. In these embodiments, the length of the support portion 143 may still satisfy To meet product demand.

[0091] In this embodiment, by properly designing the number and spacing of the support portions 143, good transmission performance of signals within the target frequency band can be achieved. Furthermore, the support portions 143 also serve as heat conductors, and their number and spacing can be designed as needed to meet the heat dissipation requirements of the traveling wave tube 1.

[0092] The slow-wave structure 14 of this embodiment has a double-layer folded line, that is, the slow-wave structure 14 is based on a coupled stripline, and thus has a fundamental mode (mode 1) and an even mode (mode 2). The slow-wave structure 14 operates in the even mode, which has an electric field in the longitudinal direction (the direction of electron beam propagation), which can interact with the electron beam to achieve electromagnetic wave signal amplification.

[0093] Figure 5 shows the transmission characteristics of the slow-wave structure 14 of this embodiment. As shown in Figure 5, within the frequency range of 34 GHz to 42 GHz, the reflection coefficient S11 of mode 2 is less than -20 dB, and the transmission coefficient S21 is approximately -5 dB, demonstrating that the slow-wave structure 14 has excellent transmission characteristics. The bandwidth of approximately 8 GHz fully meets the requirements of the traveling wave tube 1 in this frequency band. This simulation demonstrates that the structure using support portions 143 to support the slow-wave line 142 is a viable alternative to conventional structures using ceramic dielectrics to support the slow-wave line.

[0094] Through beam-wave interaction simulation, under the condition of an input power of 31mW, the beam-wave interaction simulation results of the slow-wave structure 14 are obtained as shown in Figures 6 and 7, where Figure 6 shows the output signal power and Figure 7 shows the corresponding output signal spectrum. As shown in Figures 6 and 7, the output power is 80W@40GHz, the corresponding gain is 34dB, the electronic efficiency is 12.9%, and the output signal spectrum is pure, with no obvious spurious signals within the operating frequency band. This also confirms from a simulation perspective that the traveling wave tube 1 with the slow-wave structure 14 has the function of signal amplification.

[0095] In the slow-wave structure 14 of this embodiment, the effect of the support portion 143 on the dispersion characteristics can suppress the synchronization conditions generated by the backward wave oscillation and the reflected oscillation. The support portion 143 has a jump effect on the phase velocity of the slow-wave structure 14, making it difficult to stimulate the backward wave oscillation, thereby improving the gain of the single-segment slow-wave structure. For example, simulation results show that the gain of the single-segment slow-wave structure can reach 34dB, which is significantly higher than the theoretical value of no more than 25dB for the single-segment gain of conventional slow-wave structures. In addition, because the support portion 143 has the effect of suppressing oscillations, it can solve the problem that conventional high-gain traveling wave tubes require additional cutoffs and attenuators for stability, thereby simplifying the structure and process of high-gain traveling wave tubes.

[0096] Conventional slow-wave structures using all-metal waveguide structures operate in a waveguide mode and are therefore relatively large. However, the slow-wave structure 14 in this embodiment can operate in a non-waveguide mode, such as a TEM mode or a quasi-TEM mode. This allows the slow-wave structure 14 and the traveling wave tube 1 to be smaller in size, meeting the requirements for miniaturization of communication devices.

[0097] In this embodiment, at least one slow-wave line 142 can be divided into multiple, unconnected segments, and an attenuator can be provided connected to the slow-wave line 142, such that each of the multiple segments is connected to an attenuator. For example, two adjacent segments can be connected via the same attenuator, or each segment can be connected to a different attenuator. The attenuator absorbs reflected electromagnetic waves and prevents parasitic oscillations in the traveling wave tube 1. Segmenting the slow-wave line 142 can improve the gain and stability of the traveling wave tube 1.

[0098] In this embodiment, in order to match the waveguide mode of the external circuit, such as the transverse electric mode (TE) or quasi-TE mode, a special mode converter can be designed in the input device 12 and / or the output device 16 to achieve mode conversion. This will be described below.

[0099] FIG8 illustrates the internal and external three-dimensional structure of the mode converter 17 in the first embodiment of this embodiment, and FIG9 is a schematic cross-sectional view taken along line AA of the mode converter 17 shown in FIG8 . As shown in FIG8 and FIG9 , the mode converter 17 may include a coupled stripline 171, a ridge 172, a conductive plate 173, a flat waveguide 174, a tapered waveguide 175, and a standard rectangular waveguide 176. The ridge 172, the conductive plate 173, the flat waveguide 174, the tapered waveguide 175, and the standard rectangular waveguide 176 may be made of, for example, a metal material.

[0100] As shown in Figure 8, a flat waveguide 174, a tapered waveguide 175, and a standard rectangular waveguide 176 are sequentially connected. Both the flat waveguide 174 and the standard rectangular waveguide 176 are rectangular waveguides. The tapered waveguide 175 can be trapezoidal in shape, with the end connecting to the flat waveguide 174 being narrower and the end connecting to the standard rectangular waveguide 176 being wider. The flat waveguide 174, the tapered waveguide 175, and the standard rectangular waveguide 176 form a structure with a cavity.

[0101] As shown in Figures 8 and 9 , the conductive plate 173 can be fixed within the inner cavity 174a of the flat waveguide 174, and can be positioned close to one side of the flat waveguide 174 (e.g., the left side in Figure 8 ). A gap exists between the plate surface 173a of the conductive plate 173 (the normal to the plate surface is along the thickness direction of the conductive plate 173, the same below) and the cavity wall of the inner cavity 174a opposite the plate surface 173a. A gap also exists between the plate surface 173a of the conductive plate 173 and the cavity wall of the inner cavity 174a opposite the plate surface 173b. The conductive plate 173 is relatively thin and can be a thin plate.

[0102] As shown in Figures 10-11, there can be two ridges 172, each of which can be fixed to plate surface 173a and plate surface 173b, respectively. Ridges 172 can be located near the edge of conductive plate 173. As shown in Figure 9, ridges 172 are not connected to the wall of inner cavity 174a, with a gap between them. Illustratively, ridges 172 can be roughly rectangular.

[0103] As shown in Figure 8 , coupled stripline 171 may include an outer conductor 171c and two inner conductors, with outer conductor 171c surrounding the outer circumference of the inner conductors. As shown in Figures 10 and 11 , each inner conductor may include a first portion 171a and a second portion 171b, with first portion 171a connecting second portion 171b to ridge 172. In conjunction with Figure 8 and Figure 3 , the end of second portion 171b facing away from first portion 171a may be connected to slow-wave line 142.

[0104] As shown in FIG10 , the first portion 171a may have a varying width, and the width of the first portion 171a may decrease from the ridge 172 to the second portion 171b. "Decreasing" may include a gradual decrease, or may include a decreasing width overall, but with local repetitions. For example, the first portion 171a may include a portion of uniform width and a portion of gradually varying width (the latter case); or, the first portion 171a may only have a portion of gradually varying width but no portion of uniform width (the former case). The second portion 171b may, for example, have a uniform width, with the width of the second portion 171b being smaller than the width of the first portion 171a.

[0105] In the mode converter 17 of the first embodiment, the second parts 171b of the two inner conductors in the coupled stripline 171 can be connected to the two layers of slow-wave lines 142 respectively, and the standard rectangular waveguide 176 can be connected to the external circuit. Thus, the mode converter 17 connects the slow-wave line 142 to the external circuit to achieve mutual conversion of the working modes of the two.

[0106] For example, if the mode converter 17 is used in the input device 12, the coupled stripline 171 also serves as the input line 121. The standard rectangular waveguide 176, the tapered waveguide 175, the flat waveguide 174, the conductive plate 173, and the ridge 172 all function to perform mode conversion, converting the standard waveguide mode of the external signal into the operating mode of the slow-wave structure 14 (e.g., a TEM mode or a quasi-TEM mode). The structural design of the coupled stripline 171 provides impedance matching. Thus, the mode converter 17 can achieve mode conversion and input the converted signal to be amplified into the slow-wave line 142.

[0107] Alternatively, for example, the mode converter 17 can be used in the output device 16, coupled with the stripline 171, also known as the output line 161. The ridge 172, conductive plate 173, flat waveguide 174, gradient waveguide 175, and standard rectangular waveguide 176 all function to perform mode conversion, converting the operating mode of the slow-wave structure 14 (e.g., TEM mode or quasi-TEM mode) into a standard waveguide mode for an external signal. The structural design of the coupled stripline 171 provides impedance matching. Thus, the mode converter 17 can achieve mode conversion and output the converted amplified signal to an external circuit.

[0108] FIG12 shows the transmission performance simulation results of TWT 1 after using mode converter 17. As shown in FIG12 , within the frequency range of 34 GHz to 42 GHz, the reflection coefficient S11 is less than -15 dB, and the transmission coefficient S21 is approximately -0.3 dB, indicating that TWT 1 has good transmission characteristics.

[0109] FIG13 illustrates the internal and external three-dimensional structure of the mode converter 18 in the second embodiment of this embodiment. As shown in FIG13 , the mode converter 18 may include a coupled stripline 181, a ridge 182, a flat waveguide 184, a gradient waveguide 185, and a standard rectangular waveguide 186. The ridge 182, the flat waveguide 184, the gradient waveguide 185, and the standard rectangular waveguide 186 may be made of, for example, a metal material. Comparing FIG13 with FIG12 , the differences from the mode converter 17 are that the mode converter 18 does not have a conductive plate; there is only one ridge 182, which may have a stepped structure; and the inner conductor 181b of the coupled stripline 181 may have a uniform width. This will be explained below.

[0110] As shown in FIG13 , the ridge 182 may have a first surface 182a and a second surface 182b that are opposite to each other. The second surface 182b may be a plane, and the second surface 182b may be connected to the inner wall of the inner cavity of the flat waveguide 184. Schematically, the first surface 182a may have a stepped structure, and the stepped structure may include a plurality of steps connected in sequence ( FIG13 illustrates four steps). Schematically, from the end of the ridge 182 close to the tapered waveguide 185 to the end away from the tapered waveguide 185 (for example, from the right end to the left end), these steps may rise in sequence, that is, the height of the steps may increase in sequence, so that the distance between the first surface 182a and the second surface 182b may tend to increase. The first surface 182a is not connected to the inner wall of the inner cavity of the flat waveguide 184, but has a gap therebetween.

[0111] Figure 14 illustrates a side view of the ridge 182 in another embodiment. Unlike Figure 13 , the first surface 182a of the ridge 182 shown in Figure 14 may not form a stepped structure, but may instead include a flat surface and an inclined surface. This allows the distance between the first surface 182a and the second surface 182b to decrease (from left to right). Combining Figure 14 with Figure 13 , the left end of the ridge 182 may be connected to the inner conductor 181b, while the right end of the ridge 182 may be adjacent to the tapered waveguide 185.

[0112] As shown in FIG14 , in another embodiment, the first surface 182a of the ridge 182 can be entirely beveled, similarly allowing the distance between the first surface 182a and the second surface 182b to decrease. The end of the ridge 182 with the larger distance can be connected to the inner conductor 181b, while the end with the smaller distance can be closer to the tapered waveguide 185.

[0113] In the above embodiment, by varying the spacing between the first surface 182a and the second surface 182b of the ridge 182, the ridge 182 can also function as an impedance matcher. Having more levels of spacing can achieve better impedance matching. For example, as shown in FIG13 , the stepped structure can have four steps, corresponding to three levels of spacing (or height levels), enabling the ridge 182 to have better impedance matching performance.

[0114] As shown in FIG13 , the coupled stripline 181 includes an outer conductor 181 a and two inner conductors 181 b . The two inner conductors 181 b may have uniform widths and may be connected at the end where the distance between the first surface 182 a and the second surface 182 b is greater.

[0115] The mode converter 18 can also realize the conversion between the standard waveguide mode of the external signal and the working mode of the slow-wave structure 14 .

[0116] Based on the above embodiments, other mode converter structures can be designed. For example, the gradient waveguide and standard rectangular waveguide can be eliminated, and the flat waveguide 184 can be connected to the external circuit to achieve conversion between the non-standard waveguide mode of the external signal and the operating mode of the slow-wave structure 14. In this solution, unlike the above, the end with the smallest gap between the first and second surfaces of the ridge can be connected to the inner conductor.

[0117] In this embodiment, the traveling wave tube 1 with double-layer fold lines has a stronger electromagnetic wave field, stronger interaction, and higher efficiency and gain. In other embodiments, the traveling wave tube can also be set as a single-layer fold line, and the support part also has only one layer.

[0118] The solution of this embodiment, by making the tube shell 141, slow-wave line 142 and support part 143 in the slow-wave structure 14 into an integrated structure, can improve the processing and assembly errors caused by the split design of the conventional slow-wave structure, simplify the assembly process of the entire tube, thereby shortening the overall production cycle of the traveling wave tube, and improving the yield and consistency of the traveling wave tube.

[0119] 15 and 16 are schematic structural diagrams of the slow-wave structure 14 in the second embodiment, wherein FIG15 is a schematic structural diagram of the external structure of the slow-wave structure 14 , and FIG16 is a schematic structural diagram of the internal and external structures of the slow-wave structure 14 .

[0120] Unlike the first embodiment, the slow-wave line 142 of the slow-wave structure 14 shown in Figures 15 and 16 is a circular spiral structure, and the cross-section of the circular spiral structure can be roughly circular. Schematically, the shell body 141a can be cylindrical, and the shell protrusion 141b and the shell protrusion 141c can also be cylindrical. The support portion 143 can be in the shape of a round rod. The input device and / or output device of the second embodiment can include a coaxial coupler, which is a mode converter for realizing the conversion between the operating mode of the external circuit and the operating mode of the slow-wave structure 14.

[0121] The slow-wave structure 14 of the second embodiment can meet specific product requirements by setting a spiral line.

[0122] 17 and 18 are schematic structural diagrams of the slow-wave structure 14 in Example 3, wherein FIG17 is a schematic structural diagram of the internal and external structures of the slow-wave structure 14 , and FIG18 is a schematic structural diagram of the slow-wave line 142 and the support portion 143 in the slow-wave structure 14 .

[0123] Unlike the second embodiment, in the scheme of the third embodiment, the tube shell 141 may not have a tube shell protrusion for accommodating the support portion 143, and the volume of the tube shell 141 may be smaller. In addition, each support portion 143 can be tilted relative to the slow-wave line 142, that is, the length direction of each support portion 143 can form a non-ninety-degree angle with the length direction L1 of the slow-wave line 142. The multiple support portions 143 located on each side of the slow-wave line 142 can be connected end to end in sequence to form a continuous wavy line structure. Schematically, the angles formed by any two adjacent support portions 143 and the length direction L1 can be complementary, the two spaced support portions 143 can be parallel, and the angles between each two support portions 143 can be equal. Of course, the above relative positions are only an example, and the scheme of the third embodiment does not limit this.

[0124] The solution of the third embodiment can make the support portion 143 longer by arranging the support portion 143 at an angle when the size of the tube shell 141 is limited, thereby meeting the length requirement of the support portion 143. In addition, by connecting the support portions 143, the support strength is increased.

[0125] Based on the solution of embodiment three, other alternative solutions can be obtained.

[0126] For example, in one embodiment, the length directions of all the support portions 143 may form a non-ninety-degree angle with the length direction L1 , and all the support portions 143 are substantially parallel, and all the support portions 143 are not connected to each other.

[0127] Alternatively, in another embodiment, the length directions of all the support portions 143 can form a non-ninety-degree angle with the length direction L1, and some of the support portions 143 are not connected to each other, for example, adjacent support portions 143 are not connected and are roughly parallel, or adjacent support portions 143 are not connected and their extension lines intersect, etc.; another part of the support portions 143 can be connected in sequence to form a wavy line structure.

[0128] Alternatively, in another embodiment, the length directions of some support portions 143 may be perpendicular or approximately perpendicular to the length direction L1, and these support portions 143 are not connected to each other; the length directions of other support portions 143 may form a non-ninety-degree angle with the length direction L1, wherein all support portions 143 may be connected in sequence to form a continuous wavy line structure; or a part of these support portions 143 may be connected in sequence to form a continuous wavy line structure, and the other parts are not connected to each other, for example, adjacent support portions 143 are not connected and are approximately parallel, or adjacent support portions 143 are not connected and their extension lines intersect, etc.

[0129] It is understandable that in the embodiment of the present application, for the solutions in which the support portion 143 is perpendicular or inclined relative to the slow-wave line 142, a tube shell protrusion 141b can be provided in the tube shell 141 to accommodate the support portion 143, or the tube shell protrusion 141b can be not provided according to product requirements.

[0130] Figures 19 and 20 are schematic diagrams of the structure of the slow-wave structure 14 in the fourth embodiment, wherein Figure 19 is a schematic diagram of the external structure of the slow-wave structure 14, and Figure 20 is a schematic diagram of the internal and external structures of the slow-wave structure 14. Figure 21 is a schematic diagram of the structure of the slow-wave line 142 and the support portion 143 of the slow-wave structure 14 in the fourth embodiment.

[0131] Different from the first embodiment, the slow-wave line 142 of the slow-wave structure 14 shown in Figures 20 and 21 is a rectangular spiral structure, and the cross-section of the rectangular spiral structure may be roughly rectangular. The slow-wave line 142 of the rectangular spiral structure is suitable for a strip electron beam (or square electron beam) to pass through. Schematically, the shell body 141a may be a rectangular box-shaped, the shell protrusion 141b may be a rectangular box-shaped, and the shell protrusion 141c may be cylindrical. The support portion 143 may be a square rod-shaped. The input device and / or output device of the fourth embodiment may include a coaxial coupler, which is a mode converter for realizing the conversion between the working mode of the external circuit and the working mode of the slow-wave structure 14.

[0132] The structure of the slow-wave structure 14 according to the embodiment of the present application is described in detail above. The following describes a method for manufacturing the slow-wave structure 14 using a planarization process.

[0133] Embodiment 5 provides a method for manufacturing a slow-wave structure, which can be used to manufacture the slow-wave structure 14 in any of the above embodiments. The manufacturing method may include the following steps:

[0134] S1. Provide a process file for a slow-wave structure, which may include a layout design file and a layout design file for the slow-wave structure. The layout design file may include a three-dimensional model file of the slow-wave structure (a three-dimensional model established by a modeling software) and a layered slicing file (layered slicing data obtained by processing the three-dimensional model file through layered slicing software). Figure 22 is a schematic layout of the slow-wave structure, and Figure 23 is a schematic layered slicing of the slow-wave structure. The layout design file may contain information on arranging multiple slow-wave units on a substrate. Figure 24 shows the regional allocation of the substrate, and several slow-wave structures will be arranged in each area subsequently. The process file is used for layered manufacturing on a substrate, and for manufacturing as many slow-wave structures as possible at one time on a limited substrate size.

[0135] S2. According to the process file, deposit materials layer by layer in sequence to form a slow-wave structure array.

[0136] In one embodiment, a semiconductor process may be used to sequentially deposit materials in layers on a substrate to form a slow-wave structure array.

[0137] In one embodiment, the substrate can be a metal substrate such as a copper wafer. The copper wafer can be first surface polished and cleaned to make the copper wafer have good flatness and as high a finish as possible, which is conducive to improving manufacturing accuracy and consistency of batch manufacturing, and can also reduce the loss of the slow-wave structure. Then, according to the process file, the copper wafer can be layered and electroplated in sequence to grow each layer of material in sequence. In this process, the hollow position in the slow-wave structure needs to be filled with a sacrificial layer (or mask) to support the electroplating material. After the electroplating is completed, the sacrificial layer can be removed with a corrosive solution, retaining all the electroplating materials, and cleaning to remove the residue on the surface of the electroplating material. In this embodiment, the copper wafer can be used as part of the tube shell of the slow-wave structure. Figure 25 is a schematic diagram of a slow-wave structure array electroplated on a copper wafer.

[0138] In another embodiment, the substrate can be sapphire, which has a good surface finish and flatness. The sapphire substrate and the slow-wave structure array thereon are separable, so the sapphire substrate can be peeled off after batch production, facilitating reuse of the sapphire substrate.

[0139] In another embodiment, a 3D printing process can be used to sequentially deposit materials layer by layer on a substrate to form a slow-wave structure array. The substrate and the slow-wave structure array thereon are separable, so the substrate can be peeled off after batch production.

[0140] In other embodiments, other suitable planarization processes, such as electroforming, may be used to form the slow-wave structure array.

[0141] S3. Cut the slow-wave structure array into multiple independent slow-wave structures. For solutions that require peeling off the substrate, the substrate can be removed before cutting. For solutions that do not require peeling off the substrate, the substrate and the slow-wave structure array thereon can be cut together.

[0142] In this embodiment, depending on practical circumstances, a full-thickness housing can be formed through a planarization process. Alternatively, if the planarization process limits the ability to form a partial-thickness housing, a separate outer housing can be manufactured and assembled with the slow-wave structure housing manufactured through the planarization process to form a full-thickness housing. This outer housing and the housing manufactured through the planarization process can also be referred to as sub-housings. For example, as shown in FIG26 , slow-wave structure units 14b and 14c manufactured through the planarization process can be assembled into a slow-wave structure having a double-layer fold line. This slow-wave structure housing is then assembled with outer housings 14a and 14d.

[0143] In this embodiment, the above-mentioned mode converter and slow-wave structure can also be manufactured together through a planarization process. The process file may include a layout design file and a layout design file of the slow-wave structure + mode converter. A slow-wave structure + mode converter array can be formed on a substrate through the above-mentioned planarization process. The slow-wave structure + mode converter array can be cut to prepare multiple independent slow-wave structures + mode converters, each of which is connected as one. It is understandable that the mode converter and the slow-wave structure can also be manufactured separately and then assembled, and the two are not connected as one.

[0144] After the slow-wave structure is fabricated, it can be connected to an input device, an output device, a focusing system, an electron gun, a collector, etc. to produce a traveling wave tube. This connection can be achieved by welding, including but not limited to brazing, laser welding, argon arc welding, or molecular diffusion welding.

[0145] In an embodiment of the present application, the slow-wave structure serves as a circuit for energy exchange between the electron beam of a vacuum electronic device and the electromagnetic wave, wherein the slow-wave line is a transmission line with reactance characteristics (the transmission line may have a periodic structure or a non-periodic structure). Transmission lines with reactance characteristics usually have bandpass characteristics, so the slow-wave structure can also be used as a filter, that is, the filter can include the above-mentioned shell and tube, slow-wave line and support part. The filter can be a bandpass filter, which allows signals of a certain frequency point or frequency band to pass through, while signals of other frequencies do not pass through. The filter can also be a low-pass filter. The filter can be used in any type of communication system, radar test system or measurement system.

[0146] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

Claims

1. A slow-wave structure, characterized in that: It includes a tube shell, a slow-wave line and multiple support parts, the slow-wave line and the multiple support parts are all located in the tube shell, and the tube shell, the slow-wave line and the multiple support parts are connected as a whole; the multiple support parts are distributed in sequence along the slow-wave line; one end of each support part is connected to the tube shell, and the other end is connected to the slow-wave line.

2. The slow-wave structure according to claim 1, characterized in that: The tube shell comprises a tube shell body and a plurality of tube shell protrusions, wherein the plurality of tube shell protrusions are all connected to the tube shell body, the plurality of tube shell protrusions are all protruding relative to the tube shell body, and the plurality of tube shell protrusions are sequentially spaced and distributed along the tube shell body; The slow wave line is located in the tube shell body; a part of each of the support parts is accommodated in the tube shell body, and another part of each of the support parts is accommodated in the tube shell protrusion.

3. The slow-wave structure according to claim 1 or 2, characterized in that: A length direction of at least one of the support portions is perpendicular to a length direction of the slow-wave line.

4. The slow-wave structure according to claim 1 or 2, characterized in that: The length direction of at least one of the support portions forms an angle of non-ninety degrees with the length direction of the slow-wave line.

5. The slow-wave structure according to claim 4, characterized in that: At least a portion of the plurality of support portions are sequentially connected to form a wavy line structure.

6. The slow-wave structure according to any one of claims 1 to 5, characterized in that: The plurality of support portions are respectively distributed on both sides of the slow wave line.

7. The slow-wave structure according to any one of claims 1 to 6, characterized in that: The length L of each support portion and the waveguide wavelength λ of the slow-wave structure satisfy the following relationship: n is an odd number.

8. The slow-wave structure according to any one of claims 1 to 7, characterized in that: The tube shell, the slow-wave line and the plurality of support parts are made of the same material.

9. The slow-wave structure according to any one of claims 1 to 7, characterized in that: Each of the supporting parts comprises an inner layer and an outer layer, wherein the outer layer is coated on the outer periphery of the inner layer, the inner layer is made of insulating material, and the outer layer is made of the same material as the tube shell and the slow-wave line.

10. The slow-wave structure according to any one of claims 1 to 9, characterized in that: The slow-wave structure further includes an attenuator, the slow-wave line includes a plurality of sections which are not connected to each other, and each of the plurality of sections is connected to the attenuator.

11. The slow-wave structure according to any one of claims 1 to 10, characterized in that: The slow-wave line is a folding line, and the folding line includes a plurality of bending units connected end to end in sequence, and all the bending units are coplanar.

12. The slow-wave structure according to claim 11, characterized in that: The plurality of support portions are coplanar with the slow-wave line.

13. The slow-wave structure according to claim 11 or 12, characterized in that: The slow-wave structure includes two layers of support parts, a gap is provided between the two layers of support parts, and each layer of support parts includes a plurality of support parts; the slow-wave structure includes two layers of slow-wave lines, a gap is provided between the two layers of slow-wave lines, and one layer of slow-wave lines is correspondingly connected to one layer of support parts.

14. The slow-wave structure according to any one of claims 1 to 10, characterized in that: The slow-wave line has a spiral line structure.

15. A traveling wave tube, characterized in that: It comprises an electron gun, a focusing system, a collector, an input device, an output device and the slow-wave structure according to any one of claims 1 to 14, wherein the electron gun, the focusing system, the collector, the input device and the output device are all connected to the slow-wave structure.

16. The traveling wave tube according to claim 15, characterized in that: The input device and / or the output device comprises a mode converter, the mode converter is connected to the slow-wave line, and the mode converter is used to realize the conversion between the working mode of the slow-wave structure and the working mode of the external circuit.

17. The traveling wave tube according to claim 16, characterized in that: The slow-wave structure comprises two layers of slow-wave lines; The mode converter comprises a flat waveguide, a conductive plate, a ridge and a coupled stripline; the conductive plate is arranged in the inner cavity of the flat waveguide, and the plate surfaces on opposite sides of the conductive plate and the cavity wall of the inner cavity have gaps; the ridge is arranged on the plate surface, and the ridge is not connected to the cavity wall of the inner cavity; the inner conductor of the coupled stripline comprises a first part and a second part, the first part connects the ridge and the second part, and one end of the second part facing away from the first part is connected to the two layers of the slow-wave lines; the width of the first part is greater than the width of the second part, and the width of the first part tends to decrease along the direction from the first part to the second part.

18. The traveling wave tube according to claim 16, characterized in that: The slow-wave structure comprises two layers of slow-wave lines; The mode converter includes a flat waveguide, a ridge and a coupled stripline; the ridge is arranged in the inner cavity of the flat waveguide, the ridge includes a first surface and a second surface, the first surface is opposite to the second surface, the distance between the first surface and the second surface decreases from one end of the ridge to the other opposite end, the first surface and the inner wall of the inner cavity have a gap, and the second surface is connected to the inner wall of the inner cavity; the inner conductor of the coupled stripline connects the ridge and the two layers of the slow-wave lines.

19. The traveling wave tube according to claim 18, characterized in that: The first surface has a plurality of steps connected in sequence, and the heights of the plurality of steps decrease in sequence.

20. The traveling wave tube according to any one of claims 17 to 19, characterized in that: The mode converter comprises a gradient waveguide and a standard rectangular waveguide, the gradient waveguide connects the flat waveguide and the standard rectangular waveguide, and the coupling stripline and the standard rectangular waveguide are respectively located at opposite ends of the flat waveguide.

21. A communication device, characterized in that: A traveling wave tube comprising the traveling wave tube as described in any one of claims 15 to 20.

22. The communication device according to claim 21, characterized in that The communication device is a network device, a terminal device, a vehicle-mounted device or a satellite payload.

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