WO2024059974A1 - Slow-wave structure, travelling-wave tube and communication device - Google Patents

Abstract

A slow-wave structure, a travelling-wave tube and a communication device, relating to the technical field of vacuum electronics. The slow-wave structure comprises: a conductive housing (11), which is internally provided with a vacuum shielding cavity (11a); planar zigzag slow-wave lines (12), which are located in the vacuum shielding cavity (11a), the planar zigzag slow-wave lines (12) being periodically folded metal strip-shaped lines located in the same plane and extending in a transmission direction (z) of an electron beam; an insulating structural member, which is used for fixedly suspending the planar zigzag slow-wave lines (12) in the vacuum shielding cavity (11a); and a metal ridge sheet (14), which protrudes from at least one inner surface of the conductive housing (11) arranged opposite the planar zigzag slow-wave lines (12). The present application can weaken the dispersion intensity of the slow-wave structure, substantially improves the working bandwidth of the travelling-wave tube, and effectively reduces the working voltage of the travelling-wave tube.

Description

Slow wave structures, traveling wave tubes and communication equipment Technical field

The present application relates to the technical field of vacuum electronic devices, and in particular to a slow wave structure, traveling wave tube and communication equipment.

Background technique

The 5th generation (5G) communication network has greatly increased the carrier frequency of communication by utilizing millimeter waves and even sub-millimeter waves, so it can obtain dozens of times more frequency bands than the 4th generation (4G) communication network. Broad frequency band, which is also the fundamental reason for 5G gain. However, as the wavelength decreases, the path loss of millimeter waves in free space is greater, and characteristics such as air attenuation and rain attenuation are not as good as those in low frequency bands, resulting in the coverage of millimeter waves being seriously affected. Using a traveling-wave tube (TWT) as the final amplifier can greatly increase the transmission power, thereby achieving a substantial increase in communication distance. It has now become the focus of research and discussion by standards organizations and all parties in the industry chain.

The slow-wave structure (SWS) is used to reduce the phase velocity of electromagnetic waves to the same level as the speed of electrons, so that electrons and electromagnetic waves can fully exchange energy and achieve signal amplification. As the core component of the traveling wave tube, the quality of the slow-wave structure directly determines the technical level of the traveling wave tube.

The slow wave structure of the metal slow wave line supported by the dielectric rod is a common strip planar slow wave structure, which is improved from the microstrip line slow wave structure. It can greatly reduce the accumulation of charge in the medium and can Accommodating dual electron injections at the same time can achieve lower current density and reduce the load on the cathode. However, this type of slow-wave structure has strong dispersion characteristics. The strong dispersion characteristics also mean that the traveling wave tube using this slow-wave structure has a higher operating voltage and a narrower operating bandwidth, which is not conducive to low-voltage traveling waves. The current application status of tubes cannot meet the needs of amplifying broadband millimeter wave signals in 5G communication networks.

Contents of the invention

This application provides a slow wave structure, a traveling wave tube and communication equipment, which can weaken the dispersion intensity of the slow wave structure, significantly increase the operating bandwidth of the traveling wave tube, and effectively reduce the operating voltage of the traveling wave tube.

In a first aspect, a slow wave structure is provided, including: a conductive shell with a vacuum shielding cavity inside; a planar meandering slow wave line located in the vacuum shielding cavity, the planar meandering slow wave line being located in the same plane and Periodically folded metal strip lines extending along the transmission direction of the electron beam; insulating structural members for fixedly suspending the planar meandering slow wave line in the vacuum shielding cavity; metal ridges, protrudingly arranged On at least one inner surface of the conductive shell opposite to the planar meandering slow wave line.

According to the slow wave structure provided by the embodiment of the present application, by protruding metal ridges on the inner surface of the conductive shell, the size of the vacuum shielding cavity in the thickness direction can be reduced. At this time, the electric field in the thickness direction (ie, axial direction) Being compressed, the axial electric field intensity is enhanced, and because the plane zigzag slow wave line is closer to the waveguide wall, the coupling capacitance is increased, which can effectively weaken the dispersion intensity of the slow wave structure and significantly improve the work of the traveling wave tube. bandwidth, and can effectively reduce the operating voltage and improve the efficiency of the traveling wave tube.

The simulation results also show that compared with the traditional slow wave structure, the slow wave structure provided by the embodiment of the present application has a flat dispersion curve, allowing the electron beam to synchronize with the electromagnetic wave in a wider frequency band, and the electromagnetic wave at each frequency point is consistent with the The interaction strength of the electron beam is basically the same, so that the traveling wave tube using this structure has a wider operating bandwidth, and thus the broadband design of the traveling wave tube can be realized. In addition, the simulation results also show that the slow wave structure provided by the embodiment of the present application has a lower normalized phase velocity than the traditional slow wave structure, so that the traveling wave tube using this structure has a lower operating voltage.

Optionally, the conductive housing may be a metal housing, such as an aluminum housing or a stainless steel housing, but is not limited thereto. For example, the conductive housing may also be made of non-metallic materials with conductive properties such as graphite.

Alternatively, the material of the insulating structural member may be ceramic, glass, diamond, sapphire or ruby. For example, the insulating structural member may be made of boron nitride, quartz, beryllium oxide or aluminum oxide, but is not limited thereto.

In a possible design, the slow-wave structure includes a plurality of the planar meandering slow-wave lines, and the plurality of planar meandering slow-wave lines are sequentially stacked and arranged at intervals in a thickness direction perpendicular to the transmission direction of the electron beam. .

By setting up multiple planar meandering slow-wave lines, the electromagnetic properties of the slow-wave structure are more advantageous, which helps to enhance the interaction impedance and increase the gain per unit length, making the dispersion of the slow-wave structure weaker and the operating voltage lower. And has higher operating bandwidth.

In a possible design, the insulating structural member includes a plurality of insulating dielectric rods, which are distributed on both sides of the planar meandering slow-wave line and are used to clamp the said insulating dielectric rods. Planar meandering slow wave lines are suspended in the vacuum shielding cavity.

The embodiment of this application uses an insulating dielectric rod clamping method to suspend the planar meandering slow-wave line in the vacuum shielding cavity. Compared with the traditional method of supporting the top surface of the dielectric rod, this application only has the side edges of the planar meandering slow-wave line. In contact with the inner surface of the insulating dielectric rod, the contact area of the planar meandering slow wave line with the insulating dielectric rod is smaller, which greatly reduces the volume of the medium exposed in the vacuum area and weakens the tendency of the electric field energy to concentrate in the medium. It can effectively solve the problem of charge accumulation, greatly alleviate the problem of electron bombardment of the medium, and avoid problems such as short circuit and dielectric breakdown caused by electron bombardment of the medium, thereby increasing the working stability of the slow wave structure.

In a possible design, the metal ridges are provided on both inner surfaces of the conductive shell opposite to the planar meandering slow-wave line, and the insulating dielectric rods located on both sides of the planar meandering slow-wave line The inner edges of each extend between the two metal ridges.

That is to say, the width of the metal ridge piece (ie, the dimension in the height direction) is larger than the gap between the two insulating dielectric rods, and the metal ridge piece covers the inner edge of the insulating dielectric rod. Through the above settings, the metal ridge sheet has a larger coverage area, can fully compress the electric field, and increase the axial electric field intensity as much as possible, thereby weakening the dispersion intensity of the slow-wave structure to a greater extent and improving the travel performance. The operating bandwidth of the wave tube is reduced and the operating voltage is reduced.

In one possible design, the planar meandering slow-wave line has a folding vertex, and the insulating dielectric rod and the folding vertex abut each other.

By arranging the folding vertex and the insulating dielectric rod to abut each other, the contact area between the planar meandering slow wave line and the insulating dielectric rod can be further reduced, thereby further alleviating the problem of electron bombardment of the medium and making the slow wave structure more stable. sex.

In one possible design, the planar meandering slow wave line is divided into multiple segments along the transmission direction of the electron beam, and each segment includes multiple folding cycles. All folding cycles have the same cycle length, and adjacent segments have different cycle lengths, where the cycle length is the length of the folding cycle in the transmission direction of the electron beam.

According to the slow wave structure provided by the embodiment of the present application, the planar meandering slow wave line is divided into multiple segments along the transmission direction of the electron beam. Each segment includes several periods, and adjacent segments adopt different periods. The length is used to perform phase velocity jumps, thereby making the normalized phase velocities of adjacent segments different, which can suppress the return wave oscillation and stabilize the signal output, and can improve the output power of the slow wave structure.

Optionally, along the propagation direction of the electron beam, the period length of each segment of the planar meandering slow wave line can increase, decrease, or change randomly. For example, it can increase linearly or decrease linearly.

In one possible design, the gap between two adjacent planar meandering slow-wave lines constitutes a transmission channel for electron beams, and/or, the gap between the metal ridge and the planar meandering slow-wave line The gap constitutes the transmission channel for the electron beam.

In one possible design, the vacuum shielding cavity has a rectangular parallelepiped structure, and the transmission direction of the electron beam is parallel to the long side of the cuboidal structure.

In a possible design, the slow-wave structure includes two planar meandering slow-wave lines. The planes of the two planar meandering slow-wave lines are parallel to each other and are arranged mirror-symmetrically with each other, thus helping to enhance the Interaction impedance.

In a possible design, the planar meandering slow wave line is in a V-shaped, U-shaped or N-shaped periodic folding shape.

In one possible design, the metal ridge sheet is a strip-shaped sheet structure extending along the transmission direction of the electron beam.

In a possible design, the metal ridge plate is made of at least one of copper, aluminum, silver and stainless steel.

In one possible design, the insulating dielectric rod is a long straight column extending along the transmission direction of the electron beam.

Optionally, the cross-sectional shape of the insulating dielectric rod may be any regular or irregular shape such as triangle, rectangle, circle, sector or T-shape.

In a second aspect, a traveling wave tube is provided, including: a signal input device; a signal output device; a slow wave structure provided by any of the possible designs in the first aspect, and the slow wave structure is connected to the signal input device and said signal output device.

Since the traveling wave tube adopts the slow wave structure provided by the above embodiment, the traveling wave tube also has the technical effects corresponding to the slow wave structure, which will not be described in detail here.

Optionally, the traveling wave tube provided by the embodiment of the present application can be used to amplify signals in any waveband such as microwave signals, millimeter wave signals, and terahertz frequency bands, but is not limited thereto.

Alternatively, the signal input device may be a waveguide structure or a coaxial structure. Alternatively, the signal output device may be a waveguide structure or a coaxial structure.

Optionally, the traveling wave tube also includes an electron gun. The electron gun is connected to the electron input port of the slow wave structure and is used to inject an electron injection that meets the design requirements into the slow wave structure.

For example, the electron gun may be a Pierce parallel flow gun, a Pierce convergence gun, a high conductivity electron gun, a sun-controlled electron gun, a grid-controlled electron gun, a non-interception grid-controlled electron gun, or a low-noise electron gun.

Optionally, the traveling wave tube also includes a magnetic focusing system located on the periphery of the slow wave structure. The magnetic focusing system is used to maintain the electron beam in the required shape and ensure that the electron beam passes through the slow wave structure smoothly and interacts effectively with the magnetic field. .

For example, the magnetic focusing system can be a uniform permanent magnet focusing, a guide field focusing, a periodic permanent magnet focusing, and a uniform electromagnetic focusing system, etc.

Optionally, the traveling wave tube also includes a concentrated attenuator located inside the slow wave structure. The concentrated attenuator includes microwave absorbing materials such as carburized beryllium oxide ceramics. The concentrated attenuator is used to absorb reflected waves to eliminate feedback and suppress oscillation. Purpose.

For example, a lumped attenuator may be a split attenuator.

Optionally, the traveling wave tube also includes a collector, which is connected to the electron output port of the slow wave structure and is used to collect electrons in the slow wave structure that have completed energy exchange with the electromagnetic field.

For example, the collector may be a buck collector having a relatively high operating efficiency.

In a possible design, the signal input device includes: a rectangular waveguide; a plurality of waveguide ridges provided on the inner surface of the rectangular waveguide, the plurality of waveguide ridges are connected in sequence and gradually increase in height to form a ladder-like structure, The highest waveguide ridge among the plurality of waveguide ridges is connected to the slow wave structure.

For a slow-wave structure with multiple planar meandering slow-wave lines, its signal input and output devices have an important impact on its working stability and overall performance. In the embodiment of the present application, the signal input device adopts a rectangular waveguide with multiple built-in waveguide ridges, and the multiple waveguide ridges form a ladder-like structure. The waveguide ridge has good transmission characteristics, making it easier to impedance match the slow wave structure, greatly reducing the discontinuity in the connection between the slow wave structure and the signal input device, and effectively reducing the reflection of electromagnetic waves when they are transmitted from the signal input device to the slow wave structure. , improves the transmission characteristics of the traveling wave tube, and effectively suppresses the return wave oscillation, making the transmission of electromagnetic signals in the traveling wave tube more efficient.

A computer simulation was performed on the transmission characteristics of the slow wave structure and the signal input device. The simulated transmission and reflection coefficients show that the traveling wave tube provided in this application has good transmission characteristics in the frequency range of 36GHz to 44GHz.

In a possible design, the signal input device further includes a metal block connecting the waveguide ridge and the slow wave structure.

The signal input device provided in the embodiment of the present application uses a waveguide ridge to feed signals (such as microwave signals, millimeter wave signals or signals in the terahertz frequency band). The waveguide ridge is connected to the planar meandering slow-wave line of the slow-wave structure through a metal block, which can effectively complete the conversion of the electric field mode from the TE10 mode to the quasi-TE10 mode, that is, complete the mode conversion from the standard waveguide to the slow-wave structure.

Optionally, the materials of the waveguide ridge and the metal block may be the same or different, for example, they may be copper, stainless steel, aluminum, silver, or other metal materials.

In one possible design, the metal block is a metal square prism with a trapezoidal cross-section, and the bottom surface of the metal square prism is attached to the top surface of the highest waveguide ridge.

In a possible design, the signal output device and the signal input device have the same structure.

Through the above settings, while achieving better impedance matching with the slow wave structure, it can also improve the versatility of the signal output device and the signal input device. There is no need to distinguish between the signal output device and the signal input device during installation, which can improve assembly efficiency.

In a third aspect, a communication device is provided. The communication device includes the traveling wave tube provided by any possible design of the second aspect.

Since the communication equipment uses the traveling wave tube provided in the above embodiment, the communication equipment also has technical effects corresponding to the traveling wave tube, which will not be described again here.

In a possible design, the communication device further includes: an antenna, the antenna is connected to the signal output end of the traveling wave tube.

For example, the antenna may be a horizontal half-wave dipole antenna, a vertical monopole antenna, a Winton antenna, a Yagi antenna or a dish antenna, but is not limited thereto.

In a possible design, the communication device further includes: a processor connected to the signal input end of the traveling wave tube.

Optionally, the communication device provided by the embodiment of the present application can be any wired or wireless communication device such as a base station (such as a 5G base station), a radar (such as a millimeter wave radar or a microwave radar), a vehicle-mounted device or a satellite-borne device.

In a fourth aspect, a communication device is provided. The communication device includes a housing and a slow wave structure provided by any possible design of the first aspect, and the slow wave structure is located in the housing.

Since the communication device adopts the slow wave structure provided in the above embodiment, the communication device also has technical effects corresponding to the slow wave structure, which will not be described again here.

Optionally, the communication device provided by the embodiment of the present application can be any wired or wireless communication device such as a base station (such as a 5G base station), a radar (such as a millimeter wave radar or a microwave radar), a vehicle-mounted device or a satellite-borne device.

Description of drawings

FIG. 1 shows a schematic structural diagram of an example of a slow wave structure in the related art.

FIG. 2 shows a schematic structural diagram of another example of a slow wave structure in the related art.

Figure 3 is an overall structural diagram of the slow wave structure provided by the embodiment of the present application.

FIG. 4 is a cross-sectional view from the A-A perspective in FIG. 3 .

Figure 5 is an internal structural diagram of the slow wave structure provided by the embodiment of the present application.

Figure 6 is a perspective view of the slow wave structure provided by the embodiment of the present application.

Figure 7 is a schematic diagram of the connection between a planar meandering slow-wave line and an insulating dielectric rod.

FIG8 is a diagram showing the overall structure of a planar zigzag slow-wave line.

Figure 9 is a schematic diagram of the modular structure of the traveling wave tube provided by the embodiment of the present application.

Figure 10 is a schematic diagram of the connection between the slow wave structure, the signal input device and the signal output device.

Figure 11 is a perspective view of the structure shown in Figure 10.

Figure 12 is a perspective view of the connection between the slow wave structure and the signal input device.

FIG. 13 is a schematic modular structure diagram of an example of a communication device provided by an embodiment of the present application.

Figure 14 is a schematic modular structure diagram of another example of a communication device provided by an embodiment of the present application.

Reference signs:

1. Dielectric substrate; 2. Metal slow wave line; 3. Signal input port; 4. Signal output port; 5. Dielectric rod;

10. Slow wave structure; 11. Conductive shell; 11a. Vacuum shielding cavity; 12. Planar meandering slow wave line; 12a, 12b, 12c, 12d, segmentation; 12e, input path; 12f, output path; 13. Insulating medium Rod; 14. Metal ridge piece; 16. Signal input port; 17. Signal output port; 18. Electronic input port;

20. Signal input device; 21. Rectangular waveguide; 22. Waveguide ridge; 23. Metal block;

30. Signal output device;

40. Electron gun;

50. Magnetic focusing system;

60. Centralized attenuator;

70. Collection pole;

100. Traveling wave tube;

200. Antenna;

300. Processor;

400. Shell;

x, height direction; y, thickness direction; z, electron beam transmission direction; S, transmission channel.

Detailed ways

Embodiments of the present application are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The embodiments described below with reference to the drawings are exemplary and are only used to explain the present application and cannot be understood as limiting the present application.

In the description of this application, it should be noted that, unless otherwise clearly stated and limited, the terms "installation" and "connection" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integrated connection. Ground connection; it can be a mechanical connection, an electrical connection, or mutual communication; it can be a direct connection, or an indirect connection through an intermediate medium, or an internal connection between two components or an interaction between two components. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances.

In the description of this application, it should be understood that the terms “upper”, “lower”, “side”, “front”, “rear”, “inner”, “outer”, etc. indicate an orientation or positional relationship based on the installation The orientation or positional relationship is only for the convenience of describing the present application and simplifying the description, and does 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 of the present application. .

It should also be noted that in the embodiments of the present application, the same reference numerals refer to the same components or components. For the same components in the embodiments of the present application, only one of the parts or components may be labeled as an example in the figure. Where reference numerals are used, it should be understood that the same reference numerals apply to other identical parts or components.

With the continuous development of communication technology, the fifth generation (5G) communication network has greatly increased the carrier frequency of communication by using millimeter waves or even submillimeter waves, so it can obtain a wide frequency band that is dozens of times higher than the frequency band of the fourth generation (4G) communication network, which is also the fundamental origin of 5G gain. However, as the wavelength decreases, the path loss of millimeter waves in free space is greater, and the characteristics such as air attenuation and rain attenuation are not as good as those in low frequency bands, which leads to serious impact on the coverage of millimeter waves. The traveling-wave tube (TWT) is widely used in radar, satellite communication, medical imaging, electronic countermeasures and other fields because of its excellent characteristics such as high power, wide bandwidth, low noise and high gain. In the field of communication, the use of traveling wave tubes as the final amplifier can greatly increase the transmission power, thereby achieving a significant increase in communication distance. It has strong research value and commercial value in the millimeter wave and terahertz (THz) frequency bands.

The traveling wave tube is a microwave electron tube that achieves amplification function by continuously modulating the speed of the electron beam. In the traveling wave tube, the electron beam interacts with the microwave field traveling in the slow wave structure (slow wave circuit). In the slow wave structure of 6 to 40 wavelengths, the electron beam continuously transfers kinetic energy to the microwave signal. field, thereby amplifying the signal. The traveling wave tube allows electrons to pass through a long slow wave structure. Due to the long action time, the gain is very high, and there is no resonant cavity, so the operating bandwidth is greatly increased. The traveling wave tube mainly includes many parts such as electron gun, magnetic focusing system, slow wave structure, input and output device, concentrated attenuator and collector.

The function of the electron gun is to form an electron beam that meets the design requirements. The electron gun generates an electron beam (electron beam) with the required size and current and accelerates it to a phase velocity slightly faster than the phase velocity of the electromagnetic wave traveling on the slow wave structure, in order to exchange energy with the electromagnetic field to achieve amplification. Commonly used electron guns for traveling wave tubes include Pierce parallel flow gun, Pierce convergence gun, high conductivity electron gun, positive-controlled electron gun, grid-controlled electron gun, non-interception grid-controlled electron gun and low-noise electron gun.

The magnetic focusing system is used to keep the electron beam in the required shape, ensuring that the electron beam passes smoothly through the slow-wave structure and interacts effectively with the magnetic field. The electrons in the electron beam carry negative charges, and the mutual repulsion will cause the electron beam to quickly diverge and hit the slow-wave structure, thus losing the opportunity to transfer energy to the electromagnetic field. Therefore, it is necessary to constrain the electron beam through a magnetic focusing system to allow it to pass smoothly through the slow-wave structure and fully exchange energy with the electromagnetic field to achieve signal amplification. Commonly used focusing systems in traveling wave tubes include uniform permanent magnet focusing, guide field focusing, periodic permanent magnet focusing, and uniform electromagnetic focusing systems.

Slow-wave structure (SWS) is a device that enhances the interaction between moving electrons and electromagnetic fields and converts the energy of electron flow into high-frequency energy of electromagnetic waves more effectively. The slow wave structure can reduce the phase speed of electromagnetic waves to basically the same speed as the movement speed of electrons, so that electrons and electromagnetic waves can fully exchange energy and achieve signal amplification. As the core component of the traveling wave tube, the performance of the slow wave structure directly affects the efficiency of injection-wave interaction and the technical level of the entire traveling wave tube. There are many types of slow wave structures, such as spirals, coupling cavities, folded waveguides, staggered double gratings, microstrip striplines and their deformed structures. Among them, the stripline structure has attracted much attention due to its simple structure, easy integration, easy processing, and ability to accommodate chip-shaped electronic devices.

The input and output device is also called the input and output energy coupler. The input and output device includes a signal input device and a signal output device, which are respectively connected to both ends of the slow wave structure and serve as the entrance and exit of the signal to be amplified. Common structural forms include waveguide and coaxial. Generally, a coaxial structure is used when the frequency is low or the power is small and a wide operating bandwidth is required; otherwise, a waveguide structure is used. There are also coaxial structures for input and waveguide structures for output.

A concentrated attenuator refers to a microwave absorber that contains a material that absorbs microwaves and is processed into a certain shape. Known microwave absorbing materials include attenuating ceramics such as carburized beryllium oxide ceramics and the like. At the concentrated attenuator, the reflected wave is absorbed, which can eliminate feedback and suppress oscillation. The concentrated attenuator may be disposed between the input/output device and the slow-wave structure, or may be disposed inside the slow-wave structure. The concentrated attenuator may be, for example, a ramp attenuator.

The collector is used to collect electrons that have exchanged energy with the electromagnetic field. Since the electrons still have a very high speed at this time, they will be converted into heat when they hit the collector. Therefore, heat dissipation is an important issue in the collector design. In order to improve efficiency, traveling wave tubes often use step-down collectors.

This application mainly involves the technical improvement of the slow wave structure. The slow wave structure will be introduced below with reference to the accompanying drawings. FIG. 1 shows a schematic structural diagram of an example of a slow wave structure in the related art. Among the solutions to realize planarized traveling wave tubes, a slow-wave structure composed of metal slow-wave lines supported by a dielectric substrate (i.e., microstrip line slow-wave structure) is a typical technical solution, as shown in Figure 1. The slow wave structure is loaded with a dielectric substrate 1 in the waveguide, and a metal slow wave line 2 is etched on the dielectric substrate 1. Both ends of the metal slow wave line 2 are connected to the signal input port 3 and the signal output port 4 respectively. The electron gun (not shown in the figure) emits electrons and enters the slow-wave structure from near the signal input port 3. The electron beam passes through the slow-wave structure under the focusing effect of the focusing magnetic field. The electron beam and the slow-wave structure along the metal The high-frequency field of the input signal of the wave line 2 interacts, converts the kinetic energy of the electron beam into electromagnetic wave energy and couples it to the metal slow wave line 2. Finally, the input signal is amplified and coupled to the external circuit from the signal output port 4.

In this process, in order for the electron beam to better convert kinetic energy into electromagnetic wave energy, the electron beam needs to be as close as possible to the metal slow wave line 2 and fully interact with the surface of the metal slow wave line 2 . However, when the electron injection is close to the metal slow-wave line 2, it will also cause the electrons to bombard the metal slow-wave line 2 and/or the dielectric substrate 1, causing the traveling wave tube to operate unstable or even unable to work. Therefore, it is necessary to comprehensively consider the efficiency and stability of the device to keep the electron beam at a certain distance from the metal slow-wave line 2. Even so, the design of using this dielectric substrate to support the slow-wave line still cannot avoid the bombardment of the electron beam, especially This is when the traveling wave tube works continuously for a long time.

In the above solution, in a slow wave structure composed of a metal slow wave line 2 supported by a dielectric substrate 1, on the one hand, the electric field is mainly concentrated in the dielectric substrate 1, and the electric field attenuates exponentially along the direction perpendicular to the metal slow wave line 2. Therefore, , the field interacting with the electron injection is weak, which is not conducive to achieving high efficiency and miniaturization of the traveling wave tube. On the other hand, in order to prevent the electron beam from directly bombarding the metal slow wave line 2 and the dielectric substrate 1, there is a certain distance between the electron beam and the metal slow wave line 2. However, as the traveling wave tube continues to work, electron bombardment cannot be completely avoided. Slow-wave structure, so under long-term operation, this method of using slow-wave lines supported by a dielectric substrate will have a significant charge accumulation effect, eventually leading to device breakdown. Therefore, the main technical shortcoming of this technical solution for metal slow-wave lines supported by a dielectric substrate is that the energy conversion efficiency is low, and as the working time of the traveling wave tube increases, the charge concentration effect caused by electron bombardment of the dielectric substrate causes the The traveling wave tube breaks down and causes unstable operation.

In order to solve the problem of charge concentration in the slow-wave structure shown in Figure 1, a solution in which dielectric rods on both sides are used to support metal slow-wave lines has also been proposed in related technologies. FIG. 2 shows a schematic structural diagram of another example of a slow wave structure in the related art. As shown in Figure 2, the planar slow wave structure of the metal slow wave line supported by the dielectric rod is improved from the metal microstrip line. The biggest difference between it and the metal microstrip line is the way of dielectric support, that is, this solution is set by two spacers. The dielectric rod 5 is used to replace the dielectric substrate 1 to support the metal slow wave line 2.

The electron beam has a certain distance from the metal slow wave line 2, and interacts with the surface wave transmitted in the metal slow wave line 2 during the transmission process, thereby achieving amplification of the electromagnetic wave. In this technical solution, the metal slow-wave lines are supported on both sides, which can greatly reduce the accumulation of charge in the medium, reduce the risk of electrons bombarding the medium to a certain extent, and solve the problem of charge concentration. This increases the stability of the traveling wave tube operation.

However, the dispersion of the slow-wave structure has a great correlation with many structural parameters. The solution of using dielectric rods on both sides to support the metal slow-wave line shown in Figure 2 has strong dispersion characteristics. The strong dispersion characteristics also mean that the use of The slow-wave structure of the traveling wave tube has a high operating voltage and a narrow operating bandwidth, which is not conducive to the application status of low-voltage traveling wave tubes and cannot meet the needs of amplifying broadband millimeter wave signals in 5G communication networks. .

In view of this, embodiments of the present application provide a slow wave structure, a traveling wave tube and communication equipment. By arranging metal ridges in the slow wave structure, the dispersion intensity of the slow wave structure can be weakened and the work of the traveling wave tube can be significantly improved. bandwidth, and effectively reduces the operating voltage of the traveling wave tube.

In the first aspect, the embodiment of the present application first provides a slow wave structure 10 . Figure 3 is an overall structural diagram of the slow wave structure 10 provided by the embodiment of the present application. FIG. 4 is a cross-sectional view from the A-A perspective in FIG. 3 . Figure 5 is an internal structural diagram of the slow wave structure 10 provided by the embodiment of the present application. Figure 6 is a perspective view of the slow wave structure 10 provided by the embodiment of the present application. As shown in FIGS. 3 to 6 , the slow wave structure 10 provided by the embodiment of the present application includes a conductive shell 11 , a planar meandering slow wave line 12 , an insulating structural member, and a metal ridge 14 .

Among them, the conductive shell 11 has a vacuum shielding cavity 11a inside, and the vacuum shielding cavity 11a is used to accommodate planar meandering slow wave lines 12, insulating structural parts, metal ridges 14 and other related components. Four through holes connected to the vacuum shielding cavity 11a can be opened on the conductive shell 11 to realize the input and output of signals, as well as the input and output of electron injection.

For example, one end of the conductive housing 11 is provided with a signal input port 16 and an electronic input port 18, and the other end is provided with a signal output port 17 and an electronic output port (not shown in the figure). The size and shape of each port can be reasonably designed according to actual needs.

Alternatively, the conductive housing 11 may be a metal housing, such as an aluminum housing or a stainless steel housing, but is not limited thereto. For example, the conductive housing 11 may also be made of non-metallic materials with conductive properties such as graphite.

As shown in Figures 3 and 6, the conductive housing 11 has a rectangular parallelepiped structure as a whole. At this time, the conductive housing 11 forms a standard rectangular waveguide structure. Correspondingly, the vacuum shielding cavity 11a also has a rectangular parallelepiped structure. The electronic input port 18 and the electronic output The ports are respectively provided at two opposite ends of the cuboid structure, so that the transmission direction z of the electron beam (that is, the movement direction of the electrons, that is, the beam-wave interaction direction) is parallel to the long side of the cuboid structure.

As shown in Figures 4 to 7, the planar meandering slow wave lines 12 are fixedly arranged in the vacuum shielding cavity 11a. The planar meandering slow wave lines 12 are periodic lines located in the same plane and extending along the transmission direction z of the electron beam. Folded metal strip wire. The planar meandering slow-wave line 12 is a metal strip line with a certain thickness and width. Along the extending direction of the line, the thickness and width can be the same everywhere.

For example, the planar meandering slow wave line 12 may be a V-shaped, U-shaped (including a U-shaped apex with an arc-shaped front end and a straight-angled U-shaped front end) or an N-shaped periodically folded planar curve, and its material At least one of tungsten, rhenium, copper, gold, titanium, nickel, silver and alloys thereof may be used.

Optionally, one or more planar meandering slow-wave lines 12 may be provided in the vacuum shielding cavity 11a. This application does not limit the number of planar meandering slow-wave lines 12 in the slow-wave structure 10. For example, it may be as shown in FIG. The two shown in can also be one or more, such as 3 or 4, etc.

As shown in FIGS. 4 to 7 , the insulating structural member is made of insulating material and is used to install the planar meandering slow wave line 12 inside the conductive shell 11 and to electrically isolate it from the conductive shell 11 . That is to say, the planar meandering slow-wave line 12 can be fixedly suspended in the vacuum shielding cavity 11a through the insulating structural member. This application does not specifically limit the specific structural form of the insulating structural member. For example, it can be the insulating dielectric rod 13 shown in the figure (that is, the insulating structural member can be a rod-shaped structure), or it can also be the dielectric substrate shown in Figure 1, etc. Any other regular or irregular structure.

Alternatively, the material of the insulating structural member may be ceramic, glass, diamond, sapphire or ruby. For example, the insulating structural member may be made of boron nitride, quartz, beryllium oxide or aluminum oxide, but is not limited thereto.

As shown in FIGS. 4 and 5 , the metal ridge 14 is a sheet structure made of metal material. For example, the metal ridge 14 is made of at least one of copper, aluminum, silver, stainless steel, and the like. The metal ridge piece 14 is protrudingly disposed on at least one inner surface of the conductive shell 11 opposite to the planar meandering slow wave line 12, that is, the metal ridge piece 14 and the plane where the planar meandering slow wave line 12 is located are opposite to each other, thereby reducing the vacuum. The size of the shielding cavity 11a in the thickness direction y. There is a gap between the metal ridge 14 and the planar meandering slow-wave line 12, and they are not in contact with each other.

In the embodiment of the present application, metal ridges 14 are provided on both inner surfaces of the conductive shell 11 opposite to the planar meandering slow-wave line 12 , that is, both inner surfaces on both sides of the planar meandering slow-wave line 12 are provided with metal ridges 14 . There are metal ridges 14, and the planar meandering slow wave line 12 is arranged between the two metal ridges 14. The dimensions of the two metal ridges 14 can be exactly the same and arranged symmetrically up and down.

In other implementations, the metal ridge 14 may also be provided on only one of the inner surfaces, which is not limited in this application.

According to the slow wave structure 10 provided by the embodiment of the present application, by protruding the metal ridge 14 on the inner surface of the conductive shell 11, the size of the vacuum shielding cavity 11a in the thickness direction y is reduced. At this time, the thickness direction y ( That is, the electric field in the axial direction is compressed, the axial electric field intensity is enhanced, and because the planar meandering slow wave line 12 is closer to the waveguide wall, the coupling capacitance is increased, thereby effectively weakening the dispersion intensity of the slow wave structure 10 , significantly increasing the operating bandwidth of the traveling wave tube, while effectively reducing the operating voltage and improving the efficiency of the traveling wave tube.

The simulation results also show that compared with the traditional slow wave structure, the slow wave structure 10 provided by the embodiment of the present application has a flat dispersion curve, so that the electron injection can be synchronized with electromagnetic waves in a wider frequency band, and the electromagnetic waves at each frequency point The interaction intensity with the electron beam is basically the same, so that the traveling wave tube using this structure has a wider operating bandwidth, and thus the broadband design of the traveling wave tube can be realized. In addition, the simulation results also show that the slow wave structure 10 provided by the embodiment of the present application has a lower normalized phase velocity than the traditional slow wave structure, so that the traveling wave tube using this structure has a lower operating voltage.

Furthermore, the metal ridge sheet 14 is a long sheet-like structure extending along the transmission direction z of the electron beam. That is, metal ridges 14 are provided in the entire traveling direction of the electron beam, which can compress the electric field at different positions in this direction and enhance the electric field intensity at different positions, thereby weakening the slow wave structure to a greater extent. The dispersion intensity of 10 increases the operating bandwidth of the traveling wave tube and reduces the operating voltage.

In a possible implementation, the conductive housing 11 can be formed by assembling an upper half shell and a lower half shell, and the metal ridge sheet 14 can be formed into an integral structure with the corresponding half shell by an integral molding process such as casting or powder metallurgy. In this case, the metal ridge sheet 14 is arranged on the inner surface of the corresponding half shell, and the connection strength between the two is higher.

For example, the conductive housing 11 is formed by assembling upper and lower half-shells. Two metal ridges 14 are each provided on the inner surface of one of the half-shells. The metal ridges 14 and the corresponding half-shell are integrated by a casting process. structure.

The specific structural details of the slow wave structure 10 provided in the embodiment of the present application will be further introduced below with reference to the accompanying drawings. As shown in Figures 4 and 5, in the embodiment of the present application, the slow-wave structure 10 includes a plurality of planar meandering slow-wave lines 12. The plurality of planar meandering slow-wave lines 12 are arranged in a thickness direction perpendicular to the transmission direction z of the electron beam. y are stacked one after another and set at intervals.

By arranging multiple planar meandering slow-wave lines 12, the electromagnetic properties of the slow-wave structure 10 are more advantageous, which helps to enhance the interaction impedance, improve the gain per unit length, make the dispersion of the slow-wave structure 10 weaker, and increase the operating voltage. lower and has higher operating bandwidth.

Further, at this time, the gap between the two adjacent planar meandering slow-wave lines 12 constitutes the transmission channel S of the electron beam, and/or the gap between the metal ridge 14 and the planar meandering slow-wave line 12 constitutes the electron beam. transmission channel S.

Alternatively, the gap between any two adjacent planar meandering slow wave lines 12 may constitute the transmission channel S for the electron beam. For example, there are three planar meandering slow wave lines 12 in total. In this case, the gap between the first line and the second line and the gap between the second line and the third line constitute the electron beam transmission channel S.

Alternatively, the gaps between some adjacent planar meandering slow wave lines 12 may constitute the transmission channel S for the electron beam. For example, there are three planar meandering slow wave lines 12 in total. At this time, the gap between the first and second lines constitutes the transmission channel S of the electron beam, while the gap between the second and third lines does not constitute the transmission channel S of the electron beam. Transmission channel S.

Optionally, it may be a gap between the outermost (eg, uppermost and/or lowermost) planar meandering slow-wave lines 12 of a plurality of stacked planar meandering slow-wave lines 12 and the metal ridge sheet 14 on the corresponding side. Constitute the transmission channel S for electron injection.

Further, as shown in Figures 4 and 5, the slow wave structure 10 in the embodiment of the present application has two planar meandering slow wave lines 12. The planes where the two planar meandering slow wave lines 12 are located are parallel to each other and are mirror symmetrical to each other. settings, thus helping to enhance interaction impedance. At this time, the gap between the two planar meandering slow wave lines 12 constitutes the transmission channel S for the electron beam.

In other implementations, the gap between the upper planar meandering slow-wave line 12 and the metal ridge 14 on the upper surface, and the gap between the lower planar meandering slow-wave line 12 and the metal ridge 14 on the lower surface The transmission channel of the electron beam can also be formed, so that the slow wave structure 10 has a multi-channel electron beam, such as a double electron beam or a three electron beam, so that the slow wave structure 10 has higher working efficiency and can obtain lower current. Density helps reduce the load on the cathode (electron gun).

As shown in Figures 4 and 5, in the embodiment of the present application, the insulating structural member is used to fix and suspend the planar meandering slow-wave line 12 in the vacuum shielding cavity 11a. The insulating structural member includes a plurality of insulating dielectric rods 13. , a plurality of insulating dielectric rods 13 are distributed on both sides of the planar meandering slow-wave line 12, and are used to suspend the planar meandering slow-wave line 12 in the vacuum shielding cavity 11a by clamping.

The embodiment of this application adopts the method of clamping by insulating dielectric rods 13 to suspend the planar meandering slow wave line 12 in the vacuum shielding cavity 11a. Compared with the method of supporting the top surface of the dielectric rod shown in Figure 2, this application only has The side edges of the planar meandering slow-wave line 12 are in contact with the inner surface of the insulating dielectric rod 13. The contact area between the planar meandering slow-wave line 12 and the insulating dielectric rod 13 is smaller, which greatly reduces the volume of the medium exposed in the vacuum area. And it weakens the tendency of the electric field energy to concentrate in the medium, which can effectively solve the problem of charge accumulation, greatly alleviate the problem of electron bombardment of the medium, avoid short circuit, dielectric breakdown and other problems caused by electron bombardment of the medium, thereby increasing the slow speed Operational stability of the wave structure 10 .

FIG. 7 is a schematic diagram of the connection between the planar meandering slow wave line 12 and the insulating dielectric rod 13 . As shown in Figures 5 to 7, in the embodiment of the present application, the planar meandering slow wave line 12 is a periodic folding curve that is U-shaped in each cycle (more specifically, it is a U-shaped vertex with an arc-shaped front end). , the planar meandering slow wave line 12 has a folding apex (that is, the apex angle of the U-shaped front end arc), and the insulating dielectric rod 13 is in contact with the folding apex. By arranging the folding apex and the insulating dielectric rod 13 to abut each other, the contact area between the planar meandering slow wave line 12 and the insulating dielectric rod 13 can be further reduced, thereby further alleviating the problem of electron bombardment of the medium, making the slow wave structure 10 more efficient. High work stability.

Optionally, each side of the planar meandering slow-wave line 12 has multiple folding vertices, and some or all of the multiple folding vertices are in contact with the inner surface of the insulating dielectric rod 13 on the corresponding side. This application There is no restriction on this.

As shown in Figures 6 and 7, in the embodiment of the present application, the width of each cycle of the planar meandering slow wave line 12 (ie, the size in the height direction x) is exactly the same. At this time, the folding vertex of each cycle is equal to The inner surfaces of the insulating dielectric rods 13 on the corresponding sides are in contact with each other, thereby achieving a good clamping and fixing effect on the planar meandering slow wave line 12 .

In other implementations, the widths for each folding cycle may not be exactly the same, and in this case, the folding apex of part of the cycle may not be in contact with the inner surface of the insulating dielectric rod 13 (there is a gap).

As shown in FIGS. 6 and 7 , in the embodiment of the present application, the insulating dielectric rod 13 is a long straight column extending along the transmission direction z of the electron beam. The cross-sectional shape of the insulating dielectric rod 13 may be any regular or irregular shape such as triangle, rectangle, circle, sector or T-shape.

As shown in FIGS. 4 to 7 , in the embodiment of the present application, there are two insulating dielectric rods 13 , and one is arranged on each side of the planar meandering slow wave line 12 . In other implementations, multiple insulating dielectric rods 13 can also be provided on each side of the planar meandering slow wave line 12. The multiple insulating dielectric rods 13 can be connected back and forth along the transmission direction z of the electron beam. This application does not do this. limited.

As shown in Figures 4 and 5, in an embodiment of the present application, metal ridges 14 are provided on the two inner surfaces of the conductive shell 11 opposite to the planar zigzag slow-wave line 12, and the inner edges of the insulating dielectric rods 13 located on both sides of the planar zigzag slow-wave line 12 extend between the two metal ridges 14.

That is to say, the width of the metal ridge piece 14 (ie, the dimension in the height direction x) is larger than the gap between the two insulating dielectric rods 13 , and the metal ridge piece 14 covers the inner edge of the insulating dielectric rod 13 . Through the above arrangement, the metal ridge sheet 14 has a larger coverage area, can fully compress the electric field, and increase the axial electric field intensity as much as possible, thereby weakening the dispersion intensity of the slow wave structure 10 to a greater extent. Increase the operating bandwidth of the traveling wave tube and reduce the operating voltage.

The specific structural details of the planar meandering slow wave line 12 in the embodiment of the present application will be further introduced below. Figure 8 is an overall structural diagram of the planar meandering slow wave line 12. In order to see the shape and segmentation of the meandering line more clearly, some cycles are hidden in Figure 8.

As shown in Figures 6, 8, 11 and 12, in the embodiment of the present application, the planar meandering slow wave line 12 is the most important part of the entire slow wave structure 10. It is a line with a certain width and thickness. It is formed by folding metal strips that undergo periodic twists and turns. The meandering path of the planar meandering slow wave line 12 can be divided into three parts: the input path 12e, the intermediate path and the output path 12f. The middle path is the main part of the plane meandering slow wave line 12. The specific shape characteristics of the middle path are: it contains two quarter arcs and a straight line segment connecting the two arcs. The two endpoints of the straight line segment connect the two arcs respectively. One of the endpoints of two arcs, both arcs are on the same side of the straight line segment and both are tangent to the straight line. Both the input path 12e and the output path 12f adopt curves or polylines, one end of which is connected to the first or last straight line segment in the middle path, and the other end extends to the outer surface of the metal casing. Eventually, these three segments combine to form a complete zigzag path of the slow wave structure.

As shown in Figure 8, in the embodiment of the present application, the planar meandering slow wave line 12 is divided into multiple segments along the transmission direction z of the electron beam. Each segment includes multiple folding cycles. Each segment The cycle lengths of all folding cycles within are the same, and the cycle lengths of adjacent segments are different, where the cycle length is the length of the folding cycle in the transmission direction z of the electron beam.

According to the slow wave structure 10 provided by the embodiment of the present application, the planar meandering slow wave line 12 is divided into multiple segments along the transmission direction z of the electron beam. Each segment includes several periods, and adjacent segments adopt Different period lengths are used to perform phase velocity jumps, thereby making the normalized phase velocities of adjacent segments different, which can suppress the return wave oscillation and stabilize the signal output, and can improve the output power of the slow wave structure 10. As for the specific segments The number and number of cycles P contained in each segment can be adjusted according to the intensity of the oscillation.

Alternatively, along the transmission direction z of the electron beam, the period length of each segment of the planar meandering slow wave line 12 may increase, decrease, or change randomly. For example, it can increase linearly or decrease linearly.

As a specific example, as shown in FIG. 8 , the middle path of the planar meandering slow-wave line 12 is divided into four segments, namely segment 12a, segment 12b, segment 12c and segment 12d, which are sequentially followed. The 4 segments use different cycle lengths. Specifically, the period length of segment 12a is 320 microns (um), the period length of segment 12b is 310um, the period length of segment 12c is 300um, and the period length of segment 12d is 290um, wherein segment 12a, segment The length of segment 12b and segment 12c is 30P (ie, 30 folding cycles), and the length of segment 12d is 16P (ie, 16 folding cycles). The segments 12a and 12d extend to the outside of the conductive housing 11 through the input path 12e and the output path 12f (both are polygonal lines), and are connected to the signal input device and the signal output device respectively. On the other hand, the embodiment of the present application also provides a traveling wave tube 100. FIG. 9 is a schematic diagram of the modular structure of the traveling wave tube 100 provided by the embodiment of the present application. FIG. 10 is a schematic diagram of the connection between the slow wave structure 10 and the signal input device 20 and the signal output device 30 .

As shown in Figures 9 and 10, the traveling wave tube 100 provided by the embodiment of the present application includes a signal input device 20, a signal output device 30 and the slow wave structure 10 provided by the previous embodiment. The signal input device 20 is connected to the signal input end of the slow wave structure 10 , and the signal output device 30 is connected to the signal output end of the slow wave structure 10 , that is, the slow wave structure 10 is connected to the signal input device 20 and the signal output device 30 .

Since the traveling wave tube 100 adopts the slow wave structure 10 provided in the above embodiment, the traveling wave tube 100 also has technical effects corresponding to the slow wave structure 10, which will not be described again here.

Optionally, the traveling wave tube 100 provided in the embodiment of the present application can be used to amplify signals in any waveband such as microwave signals, millimeter wave signals, and terahertz frequency bands, but is not limited thereto.

Alternatively, the signal input device 20 may be a waveguide structure or a coaxial structure. Alternatively, the signal output device 30 may be a waveguide structure or a coaxial structure.

Optionally, as shown in FIG. 9 , the traveling wave tube 100 further includes an electron gun 40 , which is connected to the electron input port 18 of the slow-wave structure 10 , and is used to inject electron beams meeting design requirements into the slow-wave structure 10 .

For example, the electron gun 40 may be a Pierce parallel flow gun, a Pierce convergence gun, a high conductivity electron gun, a positive-controlled electron gun, a grid-controlled electron gun, a non-interception grid-controlled electron gun, or a low-noise electron gun.

Optionally, as shown in Figure 9, the traveling wave tube 100 also includes a magnetic focusing system 50 located on the periphery of the slow wave structure 10. The magnetic focusing system 50 is used to maintain the electron beam in a desired shape and ensure that the electron beam passes through the slow wave structure smoothly. The wave structure 10 effectively interacts with the magnetic field.

For example, the magnetic focusing system 50 may be a uniform permanent magnetic focusing, a guided field focusing, a periodic permanent magnetic focusing, a uniform electromagnetic focusing system, etc.

Optionally, as shown in Figure 9, the traveling wave tube 100 also includes a concentrated attenuator 60 provided inside the slow wave structure 10. The concentrated attenuator 60 includes microwave absorbing materials such as carburized beryllium oxide ceramics. The concentrated attenuator 60 is made of It absorbs reflected waves to eliminate feedback and suppress oscillation.

For example, lumped attenuator 60 may be a ramp attenuator.

Optionally, as shown in Figure 9, the traveling wave tube 100 also includes a collector 70, which is connected to the electron output port of the slow wave structure 10 and is used to collect electrons in the slow wave structure 10 that have completed energy exchange with the electromagnetic field. .

For example, the collector 70 may be a buck collector with higher operating efficiency.

Figure 11 is a perspective view of the structure shown in Figure 10. FIG. 12 is a perspective view of the connection between the slow wave structure 10 and the signal input device 20 .

As shown in FIGS. 11 and 12 , in the embodiment of the present application, the signal input device 20 is a waveguide structure, including a rectangular waveguide 21 and a plurality of waveguide ridges 22 provided on the same inner surface of the rectangular waveguide 21 . The waveguide ridges 22 are connected in sequence and gradually increase in height to form a ladder-like structure. The highest waveguide ridge 22 among the plurality of waveguide ridges 22 is connected to the slow wave structure 10 to achieve the impedance between the signal input device 20 and the slow wave structure 10 match.

For the slow wave structure 10 with multiple planar meandering slow wave lines 12, its signal input and output devices have an important impact on its working stability and overall performance. In the embodiment of the present application, the signal input device 20 uses a rectangular waveguide 21 with multiple waveguide ridges 22 built in, and the multiple waveguide ridges 22 form a stepped structure. The waveguide ridge 22 has good transmission characteristics and is easier to impedance match with the slow wave structure 10, which greatly reduces the discontinuity in the connection between the slow wave structure 10 and the signal input device 20, and effectively reduces the electromagnetic wave transmission from the signal input device 20 to the slow wave structure 10. The reflection of the wave structure 10 improves the transmission characteristics of the traveling wave tube 100 and effectively suppresses the return wave oscillation, making the transmission of electromagnetic signals in the traveling wave tube 100 more efficient.

The transmission characteristics of the slow-wave structure 10 and the signal input device 20 are simulated by computer, and the simulated transmission and reflection coefficients indicate that the traveling wave tube 100 provided in the present application has good transmission characteristics within the frequency range of 36 GHz to 44 GHz.

As shown in FIGS. 11 and 12 , in the embodiment of the present application, the signal input device 20 further includes a metal block 23 connecting the waveguide ridge 22 and the slow wave structure. The metal block 23 may be a metal square prism with a trapezoidal cross-section. The bottom surface of the metal square prism is attached to the top surface of the highest waveguide ridge 22 and is connected to the planar meandering slow wave line 12 of the slow wave structure 10 .

The signal input device 20 provided in the embodiment of the present application uses a waveguide ridge 22 to feed signals (such as microwave signals, millimeter wave signals or signals in the terahertz frequency band). The waveguide ridge 22 passes through the plane of the metal block 23 and the slow wave structure 10 The meandering slow-wave lines 12 are connected, which can effectively complete the conversion of the electric field mode from the TE10 mode to the quasi-TE10 mode, that is, complete the mode conversion from the standard waveguide to the slow-wave structure.

Optionally, the materials of the waveguide ridge 22 and the metal block 23 may be the same or different, for example, they may be copper, stainless steel, aluminum, silver, or other metal materials.

As shown in FIGS. 11 and 12 , in the embodiment of the present application, the signal output device 30 and the signal input device 20 have the same structure. Through the above arrangement, while achieving better impedance matching with the slow wave structure 10 , the versatility of the signal output device 30 and the signal input device 20 can also be improved. There is no need to distinguish the signal output device 30 and the signal input device 20 during installation. Different, can improve assembly efficiency.

On the other hand, the embodiment of the present application also provides a communication device. FIG. 13 is a schematic modular structure diagram of an example of the communication device provided by the embodiment of the present application. As shown in Figure 13, the communication device provided by the embodiment of the present application includes the traveling wave tube 100 provided by the previous embodiment.

Since the communication device uses the traveling wave tube 100 provided in the above embodiment, the communication device also has technical effects corresponding to the traveling wave tube 100, which will not be described again here.

Optionally, as shown in FIG. 13 , the communication device provided by the embodiment of the present application may also include an antenna 200 provided in the housing 400 , and the antenna 200 is connected to the signal output end of the traveling wave tube 100 . The signal amplified by the traveling wave tube 100 can be emitted by the antenna 200 .

For example, the antenna 200 may be a horizontal half-wave dipole antenna, a vertical monopole antenna, a Winton antenna, a Yagi antenna, or a dish antenna, but is not limited thereto.

Optionally, as shown in Figure 13, the communication device provided by the embodiment of the present application may also include a processor 300 located in the housing 400. The processor 300 is connected to the signal input end of the traveling wave tube 100. The processor 300 Used to generate electromagnetic signals for the traveling wave tube 100 to amplify.

Optionally, the communication device provided by the embodiment of the present application can be any wired or wireless communication device such as a base station (such as a 5G base station), a radar (such as a millimeter wave radar or a microwave radar), a vehicle-mounted device or a satellite-borne device.

Figure 14 is a schematic modular structure diagram of another example of a communication device provided by an embodiment of the present application. As shown in FIG. 14 , the communication device provided by the embodiment of the present application includes a housing 400 and the slow wave structure 10 provided in the previous embodiment. The slow wave structure 10 is located in the housing 400 .

Since the communication device adopts the slow wave structure 10 provided in the above embodiment, the communication device also has technical effects corresponding to the slow wave structure 10, which will not be described again here.

Similarly, the communication device provided in this embodiment can be any wired or wireless communication device such as a base station (such as a 5G base station), a radar (such as a millimeter wave radar or a microwave radar), a vehicle-mounted device or a satellite-borne device.

The above are only specific embodiments of the present application, but the protection scope of the present application is not limited thereto. Any person familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application. should be covered by the protection scope of this application. Therefore, the protection scope of this application should be subject to the protection scope of the claims.

Claims (22)

1. A slow wave structure characterized by including:

   Conductive shell (11) with a vacuum shielding cavity (11a) inside;

   The planar meandering slow wave line (12) is located in the vacuum shielding cavity (11a). The planar meandering slow wave line (12) is a period that is located in the same plane and extends along the transmission direction (z) of the electron beam. Sexually folded metal ribbon lines;

   An insulating structural member used to fix and suspend the planar meandering slow-wave line (12) in the vacuum shielding cavity (11a);

   The metal ridge piece (14) is protrudingly provided on at least one inner surface of the conductive shell (11) opposite to the planar meandering slow wave line (12).
2. The slow wave structure according to claim 1, characterized in that the slow wave structure includes a plurality of the planar meandering slow wave lines (12), and the plurality of the planar meandering slow wave lines (12) are perpendicular to the electrons. Note that they are stacked sequentially and spaced in the thickness direction (y) of the transmission direction (z).
3. The slow wave structure according to claim 1 or 2, characterized in that the insulating structural member includes a plurality of insulating dielectric rods (13), and the plurality of insulating dielectric rods (13) are distributed in the plane tortuous slow wave structure. Both sides of the line (12) are used to suspend the planar meandering slow wave line (12) in the vacuum shielding cavity (11a) by clamping.
4. The slow wave structure according to claim 3, characterized in that the metal ridges (14) are provided on both inner surfaces of the conductive shell (11) opposite to the planar meandering slow wave line (12). ), the inner edges of the insulating dielectric rods (13) located on both sides of the planar meandering slow-wave line (12) extend between the two metal ridges (14).
5. The slow-wave structure according to claim 3 or 4, characterized in that the planar meandering slow-wave line (12) has a folding vertex, and the insulating dielectric rod (13) and the folding vertex abut each other.
6. The slow wave structure according to any one of claims 1 to 5, characterized in that the planar meandering slow wave line (12) is divided into a plurality of segments along the transmission direction (z) of the electron beam, each Each of the segments includes a plurality of folding cycles, the cycle lengths of all the folding cycles in each of the segments are the same, and the cycle lengths of adjacent segments are different, where the cycle length is Length in transmission direction (z).
7. The slow wave structure according to claim 2, characterized in that the gap between the two adjacent planar meandering slow wave lines (12) constitutes the transmission channel (S) of the electron beam, and/or the The gap between the metal ridge (14) and the planar meandering slow wave line (12) constitutes the transmission channel (S) of the electron beam.
8. The slow wave structure according to any one of claims 1 to 7, characterized in that the vacuum shielding cavity (11a) has a cuboid structure, and the transmission direction (z) of the electron beam is parallel to the cuboid structure. The long side of the structure.
9. The slow wave structure according to any one of claims 1 to 8, characterized in that the slow wave structure includes two planar meandering slow wave lines (12), and two planar meandering slow wave lines (12). 12) The planes are parallel to each other and arranged in mirror symmetry with each other.
10. The slow wave structure according to any one of claims 1 to 9, characterized in that the planar meandering slow wave line (12) is in a V-shaped, U-shaped or N-shaped periodic folding shape.
11. The slow wave structure according to any one of claims 1 to 10, characterized in that the metal ridge sheet (14) is a strip-shaped sheet structure extending along the transmission direction (z) of the electron beam.
12. The slow-wave structure according to any one of claims 1 to 11 is characterized in that the material of the metal ridge (14) includes at least one of copper, aluminum, silver and stainless steel.
13. The slow wave structure according to any one of claims 3 to 5, characterized in that the insulating dielectric rod (13) is a long straight column extending along the transmission direction (z) of the electron beam.
14. A traveling wave tube, characterized in that it comprises:

    signal input device (20);

    signal output device (30);

    The slow wave structure according to any one of claims 1-11, which connects the signal input device (20) and the signal output device (30).
15. The traveling wave tube according to claim 14, characterized in that the signal input device (20) includes:

    Rectangular waveguide (21);

    Multiple waveguide ridges (22) are provided on the inner surface of the rectangular waveguide (21). The multiple waveguide ridges (22) are connected in sequence and gradually increase in height to form a ladder-like structure. The multiple waveguide ridges (22) The highest waveguide ridge (22) is connected to the slow wave structure.
16. The traveling wave tube according to claim 15, characterized in that the signal input device (20) further includes a metal block (23) connecting the waveguide ridge (22) and the slow wave structure.
17. The traveling wave tube according to claim 16, characterized in that the metal block (23) is a metal square prism with a trapezoidal cross-section, and the bottom surface of the metal square prism is attached to the highest waveguide ridge (22) on the top surface.
18. The traveling wave tube according to any one of claims 14 to 17, characterized in that the signal output device (30) and the signal input device (20) have the same structure.
19. A communication device, characterized in that the communication device includes:

    A traveling wave tube as claimed in any one of claims 14 to 18.
20. The communication device according to claim 19, characterized in that the communication device further includes:

    Antenna (200), the antenna (200) is connected to the signal output end of the traveling wave tube.
21. The communication device according to claim 19 or 20, characterized in that the communication device further includes:

    Processor (300), the processor (300) is connected to the signal input end of the traveling wave tube.
22. A communication device, characterized by including:

    Shell(400);

    The slow wave structure according to any one of claims 1 to 13, which is located within the housing (400).

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