Relativistic magnetron with energy feedback structure

Abstract

The application discloses a relativistic magnetron with an energy feedback structure and belongs to the microwave technical field.The relativistic magnetron is a full-cavity extraction structure and comprises an anode, a cathode, an energy extraction structure and a guide magnetic field coil; wherein the energy extraction structure is provided with a ring-shaped microwave reflection plate in an output circular waveguide part, part of energy is reflected back to a cathode-anode gap, the interaction between an electron cloud and a space electromagnetic wave is enhanced, and the output power of the relativistic magnetron is improved. The application effectively improves the output power of the relativistic magnetron while guaranteeing the compactness of the device; meanwhile, the energy feedback structure is simple and easy to process.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of high power microwave, and particularly relates to a relativistic magnetron with an energy feedback structure. BACKGROUND

[0002] High power microwave generally refers to electromagnetic waves with a frequency of 1-300 GHz and a power greater than 100 MW. A high power microwave system generally includes a pulse power source, a high power microwave source, and a radiation system. With the development of application requirements, especially the application requirements in mobile platforms, miniaturization and compactness of high power microwave systems are increasingly concerned.

[0003] With the development of pulse forming network technology, the compactness technology of pulse power sources has been fully developed. In terms of high power microwave sources, the relativistic magnetron, as one of the most mature high power microwave sources, has the characteristics of low applied magnetic field and compact structure. In order to further realize the compact design of the relativistic magnetron, many axial extraction technologies have been proposed, such as diffraction output relativistic magnetrons and full-cavity extraction relativistic magnetrons. The miniaturization and compactness of high power microwave systems based on relativistic magnetrons and pulse forming networks have become one of the recent research hotspots in the field of high power microwave.

[0004] However, the output voltage capability of the compact pulse power source is suppressed. This limits the microwave power output capability of the relativistic magnetron. To solve this problem, the early solution is to use a pulse compression device (Drastic improvement in the S-band relativistic magnetron operation[J], A. Sayapin, A. Levin and Ya. E. Krasik, Applied Physics letter, vol. 95, no. 7, No. 074101, 2009). The recent solution is to use a multi-tube cascade (Cascaded relativistic magnetron with phase-locked multiport extraction[J], H. Zhou, J. Hu, J. Shi, H. Li, H. Wang, B. Hu, Y. Zhou, T. Chen, M. Yang, and T. Li, IEEE Trans. Electron Devices, vol. 70, no. 9, pp. 4854-4859, 2023). However, the above two methods seriously increase the size of the device, making it difficult to achieve the goal of compact design. SUMMARY

[0005] The present application aims at the deficiencies of the prior art, and provides a relativistic magnetron with an energy feedback structure.

[0006] The technical scheme adopted by the present application is:

[0007] A relativistic magnetron with an energy feedback structure comprises an anode, a cathode, an energy extraction structure and a guiding magnetic field coil.

[0008] The cathode comprises a cathode support rod, an upper cathode end cap, a cathode emitter, a lower cathode end cap and a cathode connecting rod, wherein the cathode emitter is coaxially arranged inside the anode.

[0009] The anode comprises an anode cylinder and N fan-shaped anode blades, wherein the N fan-shaped anode blades are uniformly distributed on the inner wall of the anode cylinder, and a fan-shaped resonant cavity is formed between adjacent fan-shaped anode blades.

[0010] The guiding magnetic field coil is coaxially arranged outside the anode.

[0011] The energy extraction structure comprises a cylindrical shell, a cylindrical inner conductor, N / 2 fan-shaped insertion plates and N coupling slits.

[0012] The cylindrical inner conductor is arranged on the output side of the anode cylinder and is smoothly connected with the anode cylinder.

[0013] The cylindrical shell is coaxially arranged outside the anode cylinder and the cylindrical inner conductor, and an annular cavity is formed between the cylindrical shell and the anode cylinder and the cylindrical inner conductor.

[0014] The coupling slits are arranged on the anode cylinder and correspond to the fan-shaped resonant cavities one by one, so that the microwave energy in the fan-shaped resonant cavities is coupled into a fan-shaped waveguide cavity through the coupling slits.

[0015] N / 2 fan-shaped insertion plates are arranged between the cylindrical shell and the anode cylinder, so that the annular cavity is divided into N / 2 fan-shaped waveguide cavities.

[0016] The annular cavity between the cylindrical shell and the cylindrical inner conductor comprises a first coaxial section, a second coaxial section and a third coaxial section from the input end to the output end, wherein the annular cavity of the second coaxial section gradually increases in both the inner radius and the outer radius, and the inner radius and the outer radius of the first coaxial section and the third coaxial section remain unchanged.

[0017] The cylindrical shell of the third coaxial section extends towards the output section to form an output circular waveguide, and the output circular waveguide is divided into a large circular waveguide section and a small circular waveguide section from the input end to the output end, and the two sections are connected by an annular microwave reflection plate.

[0018] Further, the value of N is 6≤N≤24, and is an even number.

[0019] Further, the radius of the large circular waveguide section is 100-140mm, and the radius of the small circular waveguide section is 74-92mm.

[0020] Further, the distance between the microwave reflection plate and the coaxial inner conductor is 10-60mm.

[0021] Further, the end of the cylindrical inner conductor connected with the anode cylinder is provided with a cavity to reduce the weight of the device.

[0022] Further, all components are made of stainless steel or graphite or titanium or copper.

[0023] The working principle of the present application is that the pulse power is fed into the cathode and anode gap from the cathode rod, and induces the cathode to emit electrons. The electrons emitted by the cathode form a rotating electron cloud around the cathode emitter under the action of the axial magnetic field generated by the magnetic field coil. The electron cloud interacts with the spatial electromagnetic wave in the cathode-anode gap to generate high-power microwaves. The energy of the generated high-power microwaves is extracted by the energy coupling gap and enters the coaxial transition conversion section through the fan-shaped waveguide cavity.

[0024] When the high-power microwaves are transmitted to the annular microwave reflection plate, the microwave energy is divided into two parts, one part is output in TM 01 mode through the small circular waveguide section, and the other part is reflected back to the cathode-anode gap; these microwaves reflected back to the cathode-anode gap are the same frequency and phase as the original microwaves in the cathode-anode gap, which enhances the interaction between the electron cloud and the spatial electromagnetic wave, so that the output power of the relativistic magnetron is improved.

[0025] The beneficial effects of the present application are that by setting the energy feedback structure in the relativistic magnetron, the output power of the relativistic magnetron can be effectively improved while ensuring the compactness of the device. At the same time, the energy feedback structure of the present application is simple and easy to process. Simulation shows that under the condition of 500kV voltage, the single tube reaches more than 2GW output power, which has a great improvement in compactness compared with other technologies in the background technology. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 It is a three-dimensional structure section view of the relativistic magnetron of the present application.

[0027] Figure 2 It is a three-dimensional structure section view of the relativistic magnetron of the present application.

[0028] Figure 3 It is a schematic view of the anode structure of the present application.

[0029] Figure 4A schematic diagram of the cathode structure of the present application.

[0030] Figure 5 A schematic diagram of the sector waveguide structure of the present application.

[0031] Figure 6 A schematic diagram of the energy extraction and transmission structure of the present application.

[0032] Figure 7 A waveform diagram of the output microwave power of the present application.

[0033] Reference signs: 1. anode, 1-1. sector anode blade; 2. cathode, 2-1. cathode support rod, 2-2. upper section cathode end cap, 2-3. cathode emitter, 2-4. lower section cathode end cap, 2-5. cathode connecting rod; 3. energy extraction structure, 3-1. cylindrical shell, 3-2. cylindrical inner conductor, 3-3. sector plugboard, 3-4. coupling slot, 3-5. large circular waveguide section, 3-6. small circular waveguide section, 3-7. annular microwave reflector plate; 4. guiding magnetic field coil. DETAILED DESCRIPTION

[0034] In order to better illustrate the purpose, advantages and technical ideas of the present application, the present application is further described below in combination with specific embodiments. It should be noted that the specific examples given below only serve to explain the present application in detail and do not limit the present application.

[0035] The present application is described in detail below in combination with the drawings.

[0036] As shown in the drawings, Figures 1-6 A relativistic magnetron with energy feedback structure of the present embodiment includes anode, cathode, energy extraction structure, guiding magnetic field coil.

[0037] The cathode includes cathode support rod, upper section cathode end cap, cathode emitter, lower section cathode end cap connected in sequence, and the cathode end cap and the cathode emitter are connected by the cathode connecting rod; the cathode emitter is coaxially arranged inside the anode.

[0038] The upstream cathode end cap and the downstream cathode end cap have a radius Rcap=25mm; the cathode connecting rod is a cylinder with a radius Rrod=6mm; the cathode emitter is a cylinder with a radius Rc=14.8mm.

[0039] The anode includes anode cylinder and six sector anode blades; the six sector anode blades are uniformly distributed on the inner wall of the anode cylinder along the circumference, and the sector resonant cavities are between adjacent sector anode blades.

[0040] The inner radius of the anode cylinder is Rca=60 mm; the inner radius of the fan-shaped anode blade is Ra=33 mm, and the opening angle is 20°.

[0041] The guiding magnetic field coil is coaxially arranged outside the anode.

[0042] The energy extraction structure comprises a cylindrical shell, a cylindrical inner conductor, three fan-shaped plug-in plates and six coupling slots.

[0043] The cylindrical inner conductor is arranged on the output side of the anode cylinder and is smoothly connected with the anode cylinder; the end of the cylindrical inner conductor connected with the anode cylinder is provided with a cavity to reduce the weight of the device.

[0044] The cylindrical shell is coaxially arranged outside the anode cylinder and the cylindrical inner conductor, and there is an annular cavity between the coaxial cylindrical shell and the anode cylinder and the cylindrical inner conductor.

[0045] The coupling slots are arranged on the anode cylinder and correspond to the fan-shaped resonant cavities one by one, and the microwave energy in the fan-shaped resonant cavities is coupled into a fan-shaped waveguide cavity through the coupling slots; the length of the coupling slot is 50 mm, and the coupling slot angle Aslot is 10°.

[0046] The three fan-shaped plug-in plates are arranged between the cylindrical shell and the anode cylinder, and the annular cavity is divided into three fan-shaped waveguide cavities; the inner radius of the fan-shaped waveguide cavity is 68 mm, the outer radius is 100 mm, the opening angle is 80°, and the length is 160 mm.

[0047] The cylindrical shell and the cylindrical inner conductor form a coaxial structure, and the microwave is transmitted in a TEM mode in the coaxial structure; the total length of the coaxial structure is Lcoax=262 mm.

[0048] The cylindrical shell extends in the direction of the output section to form an output circular waveguide; the output circular waveguide is divided into a large circular waveguide section and a small circular waveguide section from the input end to the output end, and the two are connected by an annular microwave reflection plate. The radius of the large circular waveguide section is 130 mm, and the length is 20 mm; the radius of the small circular waveguide section is 80 mm.

[0049] The above embodiment is calculated by using a particle simulation software. The simulation results are shown in Figure 7 Under the conditions of a working voltage of 500 kV and an axial guiding magnetic field of 0.32 T, the microwave output power is 2 GW, and the power conversion efficiency is 52%.

[0050] The above embodiment is a description of the present application and is not a limitation of the present application. Any simple transformation of the present application belongs to the protection scope of the present application.

Claims

1. A relativistic magnetron with energy feedback structure, comprising an anode, a cathode, an energy extraction structure, a guiding magnetic field coil; The cathode comprises a cathode support rod, an upper section cathode end cap, a cathode emitter, a lower section cathode end cap, and a cathode connecting rod; wherein the cathode emission body is coaxially arranged inside the anode; the anode comprises an anode cylinder and N sector-shaped anode blades; the N sector-shaped anode blades are uniformly distributed on the inner wall of the anode cylinder along the circumference, and a sector-shaped resonant cavity is formed between adjacent sector-shaped anode blades; the guiding magnetic field coil is coaxially arranged outside the anode; characterized in that the energy extraction structure comprises a cylindrical shell, a cylindrical inner conductor, N / 2 sector-shaped insertion plates and N coupling slots; the cylindrical inner conductor is arranged on the output side of the anode cylinder and is smoothly connected with the anode cylinder; the cylindrical shell is coaxially arranged outside the anode cylinder and the cylindrical inner conductor, and there is an annular cavity between the cylindrical shell and the anode cylinder and the cylindrical inner conductor; the coupling slots are arranged on the anode cylinder and correspond to the sector-shaped resonant cavities one by one, and the microwave energy in the sector-shaped resonant cavities is coupled into a sector-shaped waveguide cavity through the coupling slots; N / 2 sector-shaped insertion plates are arranged between the cylindrical shell and the anode cylinder, and the annular cavity is divided into N / 2 sector-shaped waveguide cavities; the annular cavity between the cylindrical shell and the cylindrical inner conductor is a coaxial waveguide cavity, which realizes mode transition and conversion from the sector-shaped waveguide cavities to a circular waveguide; the cylindrical shell extends towards the output section to form an output circular waveguide; the output circular waveguide is divided into a large circular waveguide section and a small circular waveguide section from the input end to the output end, and the two sections are connected by an annular microwave reflection plate.

2. A relativistic magnetron having an energy feedback structure as defined in claim 1, characterized in that, the coaxial waveguide cavity comprises a first coaxial section, a second coaxial section and a third coaxial section from the input end to the output end; the annular cavity of the second coaxial section gradually increases in inner and outer radius, and the inner and outer radii of the first and third coaxial sections remain unchanged.

3. A relativistic magnetron having an energy feedback structure as defined in claim 1, characterized in that, N is an even number in the range of 6 to 24.

4. A relativistic magnetron having an energy feedback structure as defined in claim 3, characterized in that, the radius of the large circular waveguide section is in the range of 100 to 140 mm, and the radius of the small circular waveguide section is in the range of 74 to 92 mm.

5. A relativistic magnetron having an energy feedback structure as defined in claim 4, characterized in that, the distance between the microwave reflection plate and the coaxial inner conductor is in the range of 10 to 60 mm.

6. A relativistic magnetron having an energy feedback structure as defined in claim 5, characterized in that, the end of the cylindrical inner conductor connected with the anode cylinder is provided with a hollow cavity to reduce the weight of the device.

7. A relativistic magnetron having an energy feedback structure as defined in claim 6, characterized in that, all components are made of stainless steel, graphite, titanium or copper.

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