63results about "Klystrons" patented technology

The invention belongs to the field of particle accelerator microwaves, and particularly relates to a C-band compact spherical microwave pulse compression device which comprises a shell, a dual-polarization mode coupler and a circular waveguide, a spherical energy storage cavity is formed in the shell, and the circular waveguide and the spherical energy storage cavity are communicated through a coupling hole; the dual-polarization mode coupler comprises a rectangular waveguide, a butterfly-shaped matching section and a cylindrical matching section. According to the klystron radio frequency pulse compression circuit, the radio frequency pulse with the pulse width of 2.5 microseconds of the klystron can be compressed to 300ns, the average power gain in a single pulse is more than 4 times, the peak power gain is 6.3 times, and the compression efficiency is about 54%. According to the dual-polarization mode coupler, the functions of power distribution, mode conversion and polarization mode generation are synchronously realized, a TE10 mode in a rectangular waveguide is converted into two polarization TE11 modes which are equal in amplitude and orthogonal in phase, and then the two orthogonal TE114 modes are excited in a spherical energy storage cavity.

The invention discloses a miniaturized high-efficiency multi-beam klystron based on a double-ridge porous metamaterial unit, which comprises a first cavity, a first drift tube combination, a second cavity, a second drift tube combination, a third cavity, a third drift tube combination and a fourth cavity which are connected in sequence, the second cavity is provided with a coaxial energy output device. The first cavity, the second cavity, the third cavity and the fourth cavity are all cylindrical resonant cavities, a pair of internal drift tubes and a double-ridge porous metamaterial unit are arranged in each cylindrical resonant cavity, and the pair of internal drift tubes are arranged at the two ends of each cylindrical resonant cavity; the input direction of the klystron is defined as the left side, and an internal drift tube on the left side in the cylindrical resonant cavity is fixedly connected with the double-ridge porous metamaterial unit, so that the device can realize miniaturization, low voltage and high efficiency while outputting high power.

This invention discloses a high-efficiency microwave pulse compressor, belonging to the field of high-power microwave technology. It includes a first mode converter, a first transition structure, a dispersion structure, a second transition structure, a second mode converter, and a radiation structure. These components are connected in series. The first mode converter converts the mode of the input microwave pulse into the operating mode of the dispersion structure. The mode-converted microwave pulse is efficiently transmitted to the dispersion structure via the transition structure. The dispersion structure compresses the input frequency-modulated pulse. The second transition structure and the second mode converter convert the compressed high-power short pulse into the microwave mode required for radiation. The radiation structure directionally radiates the high-power short microwave pulse to a space target. This high-efficiency microwave pulse compressor features a simple system, compact structure, and large power capacity. It has good application prospects in microwave source arraying and modularization, and is expected to improve the performance of high-power microwave systems.

The application discloses a K-band transit-time oscillator based on two-stage modulation and distributed extraction, which comprises an inner cylinder and an anode outer cylinder sleeved outside the inner cylinder, a circular annular cavity is formed between the inner cylinder and the anode outer cylinder, the cavity comprises a first drift tube, a first modulation cavity, a second drift tube, a second modulation cavity, a third drift tube, an extraction cavity and a first coaxial output waveguide which are sequentially communicated, a circular annular second coaxial output waveguide is further arranged at an output end of the inner cylinder, the first coaxial output waveguide and the second coaxial output waveguide are coaxially arranged, the extraction cavity is further communicated with the second coaxial output waveguide, and the K-band transit-time oscillator is rotationally symmetrical about a central axis of the inner cylinder. The two-stage modulation structure is adopted to increase the depth of fundamental wave current modulation, so that the output efficiency is improved, and the double-side channel distributed extraction mode is adopted to improve the output power, so that the problem that the output power is limited while high efficiency output is realized at a high frequency band is overcome.

Embodiments of the present disclosure relate to a vacuum and high voltage radio frequency system for a medical linear accelerator. A radio frequency system for a radiotherapy machine includes: a first portion including a first gas at a first pressure; a second portion comprising a second gas at a second pressure, the second gas being different from the first gas; and a component between the first portion and the second portion, the component containing a first gas at a first pressure.

The present invention discloses a method and structure for suppressing high-order mode oscillations in a multi-beam klystron. The present invention belongs to the technical field of vacuum electronic devices. The method proposed in the present invention adds a mode filter structure to the inner wall of the coaxial resonator of the multi-beam klystron. Its length is equal to half of the wavelength of the operating mode and is close to three-quarters of the wavelength of the high-order mode. Based on the principle of half-wavelength repeatability, this structure has the characteristic of having little influence on the frequency of the operating mode. Based on the principle of quarter-wavelength impedance transformation, this structure has the characteristic of having a greater influence on the high-order mode. By optimizing the design of the dimensions of the mode filter structure, it is possible to suppress spurious modes and eliminate the influence of high-order mode self-excited oscillations without affecting the frequency, field magnitude, and symmetry of the operating mode of the multi-beam klystron, providing technical support for the simulation design and engineering tube manufacturing of the multi-beam klystron.

The invention provides a method, a device and equipment for realizing miniaturization of an electronic optical system of a klystron, which can be applied to the technical field of vacuum electronic devices. The method for realizing miniaturization of the electron optical system of the klystron comprises the following steps: acquiring a first target parameter of an electron gun and an initial permanent magnet focusing system; according to the first magnetic induction intensity, the magnetic induction intensity area range of the initial permanent magnet focusing system is adjusted, and a first magnetic induction intensity curve is obtained; adjusting the initial structure parameters by simulating a working state of embedding an electron gun corresponding to the initial structure parameters into the middle permanent magnet focusing system to obtain a second magnetic induction intensity curve; and embedding the electron gun corresponding to the target structure parameter corresponding to the second magnetic induction intensity curve into the target permanent magnet focusing system to obtain the electron optical system of the target speed regulation tube.

The embodiment of the present invention discloses a cathode thermal subassembly for a klystron electron gun, comprising: a cathode base; a cathode disposed on the top of the cathode base; a thermal subassembly located in the cathode base; a heat shield fixed in the cathode base, the heat shield being disposed below the thermal subassembly; and a cathode base disposed at the bottom of the cathode base, the cathode base being configured to reduce the heat conduction of the thermal subassembly; the cathode base being a basket-shaped structure, comprising a first ring body, a second ring body, and a plurality of support rods disposed between the first ring body and the second ring body, the two ends of the support rods being respectively fixed to the first ring body and the second ring body; the first ring body and the second ring body being disposed in parallel and concentrically. By designing the cathode base at the connection between the electron gun cathode thermal subassembly and the klystron cavity structure into a basket-shaped structure, heat conduction is effectively reduced, the stability of the electron gun is improved, and the life of the klystron is extended.

The present invention relates to the technical field of high-power microwave vacuum electronic devices, and in particular to an E-type waveguide oscillator. It includes an E-type waveguide, which includes a transverse waveguide, a first tooth waveguide, a second tooth waveguide and a third tooth waveguide, wherein the first tooth waveguide, the second tooth waveguide and the third tooth waveguide are parallel to each other, and the first tooth waveguide, the second tooth waveguide and the third tooth waveguide are vertically connected to the transverse waveguide, and short waveguides are extended at both ends of the transverse waveguide, and the short waveguide is connected to the transverse waveguide as a whole, and the length of the first tooth waveguide and the second tooth waveguide is the same, and the length of the third tooth waveguide is greater than that of the first tooth waveguide and the second tooth waveguide, and a drift tube is connected between the first tooth waveguide, the second tooth waveguide and the third tooth waveguide, and the drift tube is parallel to the transverse waveguide. The present invention can effectively realize the segmentation of the resonant mode, thereby efficiently obtaining high-power microwaves of a specific frequency, and has obvious advantages in high efficiency, low impedance and easy realization of permanent magnet packaging.

The present application relates to an electron gun, which has a cathode having an electron emission surface, a planar shape of which is circular, and which emits electrons, a heater which warms the cathode, and an anode which applies a positive potential to the cathode and extracts the electrons in a certain direction. The cathode has a through-hole along a central axis of the cathode in a central portion thereof, and at least one of an opening edge portion of the through-hole on the electron emission surface side and an inner surface of the through-hole has a non-emission layer, or the opening edge portion of the through-hole on the electron emission surface side is a chamfered C face or a chamfered R face.

The invention relates to a microwave source device in the field of high-power microwave technology, in particular to a low-Q value modulation cavity with a weak magnetic field and high-efficiency relativistic klystron oscillator, belonging to the field of high-power microwave technology; the device comprises a cathode seat, a cathode, an anode outer cylinder, a reflection cavity, a modulation cavity, an extraction cavity, a trapezoidal collector, an output waveguide, an inner cylinder, and a solenoid magnetic field, and the entire structure is rotationally symmetric about a central axis OO'; the magnetic field intensity adopted by the invention is 0.37 T, belonging to a weak magnetic field environment, and the low-Q value modulation cavity introduced at the same time cannot store a large amount of energy, resulting in partial microwave energy leakage in the modulation cavity and direct coupling to the extraction cavity, forming a first-level extraction; in a drift tube, an electron beam absorbs part of the leaked microwave energy and re-accelerates it to become a high-energy electron, and is extracted again in the extraction cavity, forming a second-level extraction, and finally, under the conditions of a voltage of 494 kV, a current of 6 kA, and a magnetic field of 0.37 T, a 1.5 GW microwave output is achieved, and a working efficiency of 50.3% is achieved.

The embodiment of the invention provides a vacuum electron tube, a radio frequency module and communication equipment, and relates to the technical field of vacuum electron tubes. The vacuum electron tube comprises a metal shell and a sealing cover plate. The sealing cover plate is connected to the metal shell in a covering mode, the sealing cover plate and the metal shell are used for defining a vacuum cavity, and an energy conversion structure is arranged in the vacuum cavity. Wherein the sealing cover plate comprises a dielectric layer structure and a metal layer structure, the metal layer structure forms a signal transmission structure, and the signal transmission structure is coupled with the transduction structure. And the signal transmission structure is used for inputting a radio frequency signal outside the vacuum cavity into the transduction structure, or the signal transmission structure is used for outputting the radio frequency signal processed by the transduction structure from the vacuum cavity. Therefore, the assembly of the vacuum electronic tube can be simpler, and the refinement and consistency of the vacuum electronic tube can be improved.

According to one embodiment, a klystron includes a high-frequency interaction unit, a main magnet arranged in a ring shape around the high-frequency interaction unit, an output waveguide, an auxiliary magnet arranged in a ring shape opposing the output waveguide, an output unit for extracting high-frequency power from the output waveguide, and an output adjustment mechanism which adjusts the output of the high-frequency power extracted from the output unit by deforming the output waveguide. In the output adjustment mechanism, the output waveguide is deformed by engaging a distal end of a jig inserted from an outside of the auxiliary magnet via a jig insertion hole with an engagement member and pushing or pulling the engagement member.

The present invention relates to a multi-gap resonator and a method for designing the same. The resonator of the present invention comprises an electron beam channel, a first coupling cavity and a second coupling cavity symmetrically arranged with respect to the electron beam channel, and a plurality of gap cavities respectively communicating with the electron beam channel and the first and second coupling cavities, and at least one electric wall respectively arranged in the first and second coupling cavities, which electric wall causes at least one non-working mode of the resonator to be cut off. The method for designing the multi-gap resonator according to the present invention can reduce the non-working resonant modes and increase the mode separation; and due to the increased mode separation, it is possible to use more gap cavities to improve the characteristic impedance of the interaction mode. Thus, a multi-gap resonator with significantly improved characteristic impedance can be obtained.

The invention belongs to the technical field of microwave vacuum electronics, and particularly provides a slow wave structure based on moving standing wave work, which is used for realizing the design targets of high power, high gain and wide bandwidth of a vacuum electronic device. According to the invention, a rectangular folded slow-wave structure which is a traveling-wave-type slow-wave line is creatively adopted to replace a distributed multi-gap structure in a traditional extended interaction klystron, and a novel resonant cavity of an upper coupled cavity / traveling-wave-type slow-wave line / lower coupled cavity is obtained, so that the novel slow-wave structure can have traveling wave characteristics and standing wave characteristics at the same time. Stronger characteristic impedance and wider bandwidth are obtained; the novel slow-wave structure is applied to a vacuum electronic device as a high-frequency structure, can achieve the design targets of high power, high gain and wide bandwidth of the vacuum electronic device, has the advantage of good cavity consistency, can effectively reduce the complexity of a cavity compared with an existing device, and improves the reliability of the vacuum electronic device. And the magnetic field distribution design difficulty and the device processing difficulty are greatly reduced.

A power module comprises a high frequency switching electronic power conditioner including stacked rectifier / filters, the stacked rectifier / filters generating stacked DC output voltages; and a vacuum electronic device coupled to the high frequency switching electronic power conditioner, the vacuum electronic device including components, each component receiving a respective DC output voltage of the stacked DC output voltages.

The invention provides an open type absorption cavity for a TM220 higher-order mode klystron and a preparation method and application of the open type absorption cavity. The open type absorption cavity is arranged in a magnetic field distribution area of a TM120 mode and a TM210 mode in an output cavity of a high-order mode klystron, and comprises a frame structure and an attenuation material body filled in the frame structure, the frame structure comprises an upper base, a lower base and a plurality of connecting pieces, the upper base and the lower base are arranged in parallel, the connecting pieces are vertically connected between a plurality of pairs of aligned corners of the upper base and the lower base respectively, a cavity structure with an open side face is defined by the upper base, the lower base and the connecting pieces, and the cavity structure is filled with the attenuation material body; the outer side faces of the attenuation material body and the peripheral face of the connecting piece are arranged in a coplanar mode, the open state of the four outer side faces of the attenuation material body is kept through the frame structure, the open outer side faces make direct contact with and are coupled with a magnetic field generated in an output cavity of the high-order mode klystron, and suppression and absorption of a TM120 mode and a TM210 mode are achieved.

The invention provides a vacuum electronic device. The vacuum electronic device is an extended interaction klystron amplifier with a planar extended interaction resonant cavity as a transduction structure, wherein the planar extended interaction resonant cavity is composed of two groups of symmetrical planar circuits. The amplifier combines the advantages of a klystron and a traveling wave tube transduction structure, and has the characteristics of stability (unidirectivity), planarization and miniaturization under the condition of small and medium power.

The utility model discloses a klystron device and an electron accelerator, the klystron device comprises a klystron main body, a klystron collector and an electron transmission device, the electron transmission device comprises a focusing coil and an electron transmission tube, and the focusing coil of the electron transmission device is arranged at the outer side of the klystron collector; one end of the klystron collector is connected with the tail end of the klystron main body, and the other end of the klystron collector is connected with the electron transport tube; the electron transport tube is connected with the front end of an accelerating tube in the electron accelerator; a waveguide is arranged at the tail end of the klystron main body, the waveguide is connected with the front end of the accelerating tube, and electrons are accelerated by a microwave field transmitted by the waveguide after entering the accelerating tube through the electron transmission tube. An electron gun on the top of a traditional accelerating tube is omitted, the system structure is simplified, the system cost is reduced, and meanwhile the system failure rate is reduced.

The present invention belongs to the field of microwave vacuum electronics technology, and specifically provides a slow-wave structure based on traveling standing waves to achieve the design goals of high power, high gain and wide bandwidth of vacuum electronic devices. The present invention creatively adopts a traveling wave type slow-wave line of a rectangular folded slow-wave structure to replace the distributed multi-gap structure in the traditional extended interaction klystron, and obtains a new resonant cavity of upper coupling cavity / traveling wave type slow-wave line / lower coupling cavity, so that the new slow-wave structure can have both traveling wave characteristics and standing wave characteristics, and obtain stronger characteristic impedance and wider bandwidth; the new slow-wave structure is applied as a high-frequency structure in vacuum electronic devices, which can achieve the design goals of high power, high gain and wide bandwidth of vacuum electronic devices, and has the advantage of good cavity consistency. Compared with existing devices, it can effectively reduce the complexity of the cavity, greatly reduce the difficulty of magnetic field distribution design and device processing difficulty.

The invention relates to the field of microwave vacuum electronic amplification devices, and particularly provides a double-staggered coupled cavity expansion interaction klystron with a trapezoidal sub-wavelength hole high-frequency structure, which comprises an input cavity, a plurality of middle cavities, an output cavity, a rectangular electron beam channel and a drift tube, and is characterized in that the input cavity, the plurality of middle cavities and the output cavity are sequentially connected through the drift tube; the input cavity, the middle cavity and the output cavity all adopt a double-staggered coupled cavity structure; on the basis, in the input cavity, the middle cavity and the output cavity, the resonant cavities are connected with the upper coupling cavity and the lower coupling cavity through the isosceles trapezoid sub-wavelength holes, and the long bottom edges of the isosceles trapezoid sub-wavelength holes and the wide edges of the resonant cavities are arranged in equal proportion, so that the electric field energy is more gathered in an electron beam channel, the characteristic impedance is increased, and the interaction efficiency is improved; meanwhile, the quality factor is reduced, and parasitic oscillation is avoided. Compared with an existing structure, the expansion interaction klystron has obvious advantages in the aspects of high power, high gain, high efficiency and wide bandwidth.

The invention relates to an input cavity injection structure of a relativistic klystron amplifier in the technical field of high-power microwaves, in particular to a compact internal injection structure of a TE10-TM01-TEM mode, and belongs to the technical field of high-power microwaves. According to the structure, a single standard rectangular waveguide is introduced to the tail of a relativistic klystron amplifier to serve as an injection waveguide, then injected microwaves are transmitted through a hollow circular waveguide, a mode converter is connected to the left side of the circular waveguide, and finally the injected microwaves are transmitted to an input cavity gap through a coaxial waveguide; when the device works, seed source microwaves are injected through the standard rectangular waveguide, the microwave transmission mode of the seed source microwaves is a TE10 mode, then the seed source microwaves are converted into a TM01 single-mode transmission mode through the hollow circular waveguide, and finally the seed source microwaves are converted into a TEM mode through the mode converter to be transmitted to the front end of the input cavity. According to the invention, the integrity of the magnetic field of the solenoid coil is kept while the high transmission characteristic is ensured, and meanwhile, a non-rotational symmetry mode caused by an overlarge over-mode ratio is avoided.

The present invention provides a focusing device, comprising: a magnetic field uniformization component, which is used to uniformize the magnetic field of the component to be focused; a first focusing component, which is used to generate a focusing magnetic field, and the first focusing component includes a first permanent magnet structure and a second permanent magnet structure, and the first permanent magnet structure is arranged outside the second permanent magnet structure; a second focusing component, which includes a third permanent magnet structure and a fourth permanent magnet structure, and the third permanent magnet structure is arranged outside the fourth permanent magnet structure; the third permanent magnet structure and the first permanent magnet structure have opposite magnetization directions, and the fourth permanent magnet structure and the second permanent magnet structure have opposite magnetization directions; a magnetic conductive component, which is arranged at both ends of the first focusing component and is used to connect the first focusing component and the second focusing component. The focusing device of the present invention solves the technical problem of the huge weight and volume of the beam focusing system in the related art.

The application discloses a K-band transit-time oscillator based on a last pre-cavity extraction structure, which comprises an inner cylinder and an anode outer cylinder sleeved outside the inner cylinder, a circular annular cavity is formed between the inner cylinder and the anode outer cylinder, the cavity comprises a first drift tube, a first modulation cavity, a second drift tube, a second modulation cavity, a third drift tube, an extraction cavity and a first coaxial output waveguide which are sequentially communicated, the output end of the anode outer cylinder is further provided with a circular annular second coaxial output waveguide, the first coaxial output waveguide and the second coaxial output waveguide are coaxially arranged, the second modulation cavity is further communicated with the second coaxial output waveguide, and the K-band transit-time oscillator is rotationally symmetrical about the central axis of the inner cylinder. The application verifies the feasibility of extracting microwave by the last pre-cavity, and realizes higher efficient output and higher power output.

The invention belongs to the technical field of high-power microwave synthesis and pulse compression, and particularly relates to a high-power microwave synthesis pulse compressor, which comprises a distributed synthesis front end, a multi-path radial synthesizer and a plasma pulse compressor which are arranged in sequence, the distributed synthesis front end comprises a plurality of groups of two-in-one high-isolation coaxial-rectangular waveguide synthesizers, rectangular waveguide transition sections and 90-degree bent waveguides which are arranged in sequence; and the input end of each two-in-one high-isolation coaxial-rectangular waveguide synthesizer is used for connecting two coaxial input ports. High-power synthesis of multi-path solid-state components can be realized efficiently with high isolation, efficient pulse compression is realized, the structure is compact, the number of synthesis paths is convenient to adjust, the power capacity is high, and the application in the high-power microwave field is met.

The utility model belongs to the technical field of high-power microwaves, and particularly relates to a TEM mode capacitor loading coaxial resonant cavity for a P-band klystron, which comprises an outer conductor, two ends of the outer conductor are respectively and fixedly connected with a first blocking plate and a second blocking plate, a first cavity is arranged in the outer conductor, an inner conductor is arranged in the first cavity, and a second cavity is arranged in the inner conductor. The length of the inner conductor is smaller than that of the outer conductor, one end of the inner conductor is fixedly connected with the side, close to the second blocking plate, of the first blocking plate, a gap is formed between the other end of the inner conductor and the side, close to the first blocking plate, of the second blocking plate, the gap is L1, a gap is formed between the outer side wall of the inner conductor and the inner side wall of the outer conductor, and a second cavity is formed in the inner conductor. A first through hole is formed in the first blocking plate and communicated with the first cavity through the second cavity, and a second through hole is formed in the second blocking plate in the length direction of the outer conductor and communicated with the first cavity. Compared with a double-in cylindrical resonant cavity, the transverse size of the resonant cavity is obviously reduced.

The application discloses an X-band high-power wideband velocity modulation tube amplifier, comprising: an electron beam emitting module for generating a circular high-impedance high-current relativistic electron beam; a wideband injection module for externally injecting a microwave signal, absorbing the microwave signal, and preliminarily velocity modulating the high-current relativistic electron beam generated by the electron beam emitting module to convert the high-current relativistic electron beam into a gap electric field modulation electron beam; a high-frequency interaction module for further modulating the gap electric field modulation electron beam converted by the wideband injection module and generating bunching to increase the fundamental wave current modulation depth of each frequency of the high-current relativistic electron beam; and a wideband extraction module for converting the kinetic energy of the electron beam after the bunching of the high-frequency interaction module into microwave energy and coupling the microwave energy to an external circuit. The velocity modulation tube amplifier can realize high-power microwave output of corresponding frequencies and improve the working bandwidth of the velocity modulation tube amplifier in the X-band.

The invention relates to a microwave source device in the technical field of high-power microwaves, in particular to a low-intensity magnetic field high-efficiency relativistic klystron oscillator with a low-Q-value modulation cavity, and belongs to the technical field of high-power microwaves. Comprising a cathode seat, a cathode, an anode outer cylinder, a reflection cavity, a modulation cavity, an extraction cavity, a trapezoidal collector, an output waveguide, an inner cylinder and a solenoid magnetic field, and the whole structure is rotationally symmetrical about a central axis OO '; the adopted magnetic field intensity is 0.37 T and belongs to a low-intensity magnetic field environment, meanwhile, the introduced low-Q-value modulation cavity cannot store a large amount of energy, so that part of microwave energy in the modulation cavity leaks and is directly coupled to the extraction cavity, and first-stage extraction is formed; and in the drift tube, the electron beam absorbs part of leaked microwave energy and is accelerated again to form high-energy electrons, the high-energy electrons are extracted again in the extraction cavity to form second-stage extraction, and finally, 1.5 GW microwave output is realized under the conditions that the voltage is 494 kV, the current is 6 kA and the magnetic field is 0.37 T, and the working efficiency is 50.3%.

The invention relates to the technical field of vacuum electronic devices, and provides a composite cathode, a cathode focusing electrode structure and a preparation method of the composite cathode. The composite cathode comprises a cathode body and a composite ring, a spherical groove is formed in one end of the cathode body, the composite ring is arranged on the peripheral wall of the cathode body in a sleeving mode and is arranged on the inner side of the focusing electrode in an inserted mode, the composite ring is provided with an annular face extending in the circumferential direction of the composite ring, and at least part of the composite ring is exposed out of a notch of the spherical groove. The annular surface is positioned between the inner wall surface of the spherical groove and the inner wall surface of the focusing electrode; and the annular surface and the inner wall surface of the spherical groove form a smooth curved surface. According to the composite cathode disclosed by the invention, the turning quality of the cathode curved surface corresponding to the composite cathode can be ensured, the laminar flow property of the electron beam at the outer edge of the cathode is greatly improved, and the transmission state of the electron beam is ensured.

The application discloses a radial electron beam staggered grid structure traveling wave amplifier, which comprises coaxial staggered grid leaves with different radii and made of metal at the lower side and the upper side of upper and lower metal ring shells, the lower side and the upper side of the grid leaves are staggered, and a cavity is formed between the lower side and the upper side of the grid leaves, thereby forming a slow wave structure. Electromagnetic waves are injected from the cavity between two adjacent grid leaves at the lower side of the upper metal ring shell or the upper side of the lower metal ring shell near a hot cathode through an input structure as a signal to be amplified, the electromagnetic waves are transmitted along the cavity in the coaxial staggered grid and interact with electron beams transmitted along the radial direction, thereby converting electron kinetic energy into electromagnetic wave energy, amplifying the input electromagnetic wave signal, and outputting the amplified electromagnetic waves from the lower metal ring shell or the upper metal ring shell through an output structure. The application has the characteristics of high interaction efficiency, high output power, high coupling impedance and simple structure.