Relativistic magnetron with energy feedback structure

Abstract

The invention discloses a relativistic magnetron with an energy feedback structure, and belongs to the technical field of microwaves. The relativistic magnetron is of a full-cavity extraction structure and comprises an anode, a cathode, an energy extraction structure and a guide magnetic field coil. According to the energy extraction structure, an annular microwave reflecting plate is adopted in an output circular waveguide part, part of energy is reflected back to a gap between a cathode and an anode, the interaction between electron cloud and space electromagnetic waves is enhanced, and the output power of a relativistic magnetron is improved. According to the relativistic magnetron, the output power of the relativistic magnetron is effectively improved while the compactness of the device is ensured; meanwhile, the energy feedback structure is simple and easy to process.

Description

Technical Field

[0001] The present invention belongs to the technical field of high-power microwave, and particularly relates to a relativistic magnetron with an energy feedback structure. Background Art

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

[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 external magnetic field and compact structure. In order to further achieve the compact design of the relativistic magnetron, many axial extraction technologies have been proposed, such as the diffractive output relativistic magnetron and the full-cavity extraction relativistic magnetron, etc. The miniaturized and compact high-power microwave system based on the relativistic magnetron and the pulse forming network has become one of the research hotspots in the field of high-power microwave recently.

[0004] However, the output voltage capacity of the compact pulse power source is inhibited. This limits the microwave power output capacity of the relativistic magnetron. To solve this problem, the early solution was 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 multi-tube cascading (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 volume of the device, making it difficult to achieve the compact design goal. Summary of the Invention

[0005] In view of the deficiencies of the prior art, the present invention proposes a relativistic magnetron with an energy feedback structure. The structure of the present invention is compact, and the output power of the relativistic magnetron at low operating voltages is improved.

[0006] The technical solution adopted by the present invention is as follows:

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

[0008] The cathode includes 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 includes an anode cylinder and N sector-shaped anode vanes; the N sector-shaped anode vanes are evenly distributed along the circumference on the inner wall of the anode cylinder, and a sector-shaped resonant cavity is formed between adjacent sector-shaped anode vanes;

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

[0011] It is characterized in that the energy extraction structure includes a cylindrical outer shell, a cylindrical inner conductor, N / 2 sector-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 to the anode cylinder;

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

[0014] The coupling slits 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 radially coupled to a sector-shaped waveguide cavity through the coupling slits;

[0015] N / 2 of the sector-shaped insertion plates are arranged between the cylindrical outer shell and the anode cylinder, dividing the annular cavity into N / 2 sector-shaped waveguide cavities;

[0016] The annular cavity between the cylindrical outer shell and the cylindrical inner conductor is successively a first coaxial section, a second coaxial section, and a third coaxial section from the input end to the output end; wherein, the inner and outer radii of the annular cavity in the second coaxial section gradually increase, and the inner and outer radii of the first coaxial section and the third coaxial section remain unchanged;

[0017] The cylindrical outer shell of the third coaxial section 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 are connected by an annular microwave reflector.

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

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

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

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

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

[0023] The working principle of the present invention is: Pulse power is fed into the cathode - anode gap from the cathode rod and induces the cathode to emit electrons. The electrons emitted by the cathode form an electron cloud rotating 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 generated high - power microwave energy is extracted by the energy coupling slot and enters the coaxial transition conversion section through the sector waveguide cavity.

[0024] When the high - power microwave is transmitted to the annular microwave reflector, the microwave energy is divided into two parts. One part is output in the TM 01 mode through the small circular waveguide section, and the other part is reflected back into the cathode - anode gap; these microwaves reflected back into the cathode - anode gap are in the same frequency and phase as the original microwave field in the cathode - anode gap, enhancing the interaction between the electron cloud and the spatial electromagnetic wave, and enabling the output power of the relativistic magnetron to be increased.

[0025] The beneficial effects of the present invention are: By setting an energy feedback structure in the relativistic magnetron, while ensuring the compactness of the device, the output power of the relativistic magnetron can be effectively increased. At the same time, the energy feedback structure of the present invention is simple and easy to process. Through simulation, under the condition of a 500 kV voltage, a single tube reaches an output power exceeding 2 GW, showing a significant improvement in compactness compared with other technologies in the background art. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a three - dimensional structural cross - sectional schematic diagram of the relativistic magnetron of the present invention.

[0027] Figure 2 It is a cross - sectional schematic diagram of the structure of the relativistic magnetron of the present invention.

[0028] Figure 3 It is a schematic diagram of the anode structure of the present invention.

[0029] Figure 4Schematic diagram of the cathode structure of the present invention.

[0030] Figure 5 Schematic diagram of the partial structure of the sector waveguide of the present invention.

[0031] Figure 6 Schematic diagram of the energy extraction and transmission structure in Embodiment 1 of the present invention.

[0032] Figure 7 Waveform diagram of the output microwave power in Embodiment 1 of the present invention.

[0033] Explanation of reference numerals: 1. Anode, 1-1. Sector anode blade; 2. Cathode, 2-1. Cathode support rod, 2-2. Upper cathode end cap, 2-3. Cathode emitter, 2-4. Lower cathode end cap, 2-5. Cathode connecting rod; 3. Energy extraction structure, 3-1. Cylindrical outer shell, 3-2. Cylindrical inner conductor, 3-3. Sector-shaped insertion plate, 3-4. Coupling slit, 3-5. Large circular waveguide section, 3-6. Small circular waveguide section, 3-7. Annular microwave reflector; 4. Guiding magnetic field coil. Detailed implementation manners

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

[0035] The present invention will be described in detail below in conjunction with the accompanying drawings.

[0036] As Figures 1-6 shown, a relativistic magnetron with an energy feedback structure in this embodiment includes an anode, a cathode, an energy extraction structure, and a guiding magnetic field coil.

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

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

[0039] The anode includes an anode cylinder and 6 sector anode blades; the 6 sector anode blades are evenly distributed along the circumference on the inner wall of the anode cylinder, and a sector resonant cavity is formed between adjacent sector anode blades.

[0040] The inner radius Rca of the anode cylinder is 60 mm; the inner radius Ra of the sector anode blade is 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 includes a cylindrical outer shell, a cylindrical inner conductor, 3 sector-shaped inserts, and 6 coupling slots.

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

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

[0045] 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 radially coupled to a sector-shaped waveguide cavity through the coupling slots; the length of the coupling slots is 50 mm, and the coupling slot angle Aslot is 10°.

[0046] The 3 sector-shaped inserts are arranged between the cylindrical outer shell and the anode cylinder, dividing the annular cavity into 3 sector-shaped waveguide cavities; the inner radius of the sector-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 outer shell and the cylindrical inner conductor form a coaxial structure, and microwaves are transmitted in the TEM mode in the coaxial structure. The total length Lcoax of the coaxial structure is 262 mm.

[0048] The cylindrical outer 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 are connected by an annular microwave reflector. Among them, 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] Calculations are carried out using particle simulation software according to the above embodiments. The simulation results are as Figure 7 shown. 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 embodiments are illustrative of the present invention and not restrictive thereof. Any simply transformed scheme of the present invention belongs to the protection scope of the present invention.

Claims

1. A relativistic magnetron with an energy feedback structure, comprising an anode, a cathode, an energy extraction structure, and a guiding magnetic field coil; The cathode includes 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; The anode includes an anode cylinder and N sector-shaped anode vanes; the N sector-shaped anode vanes are uniformly distributed along the circumference on the inner wall of the anode cylinder, and a sector-shaped resonant cavity is formed between adjacent sector-shaped anode vanes; The guiding magnetic field coil is coaxially arranged outside the anode; It is characterized in that the energy extraction structure includes a cylindrical outer shell, a cylindrical inner conductor, N / 2 sector-shaped inserts, and N coupling slots; The cylindrical inner conductor is arranged on the output side of the anode cylinder and is smoothly connected to the anode cylinder; The cylindrical outer shell is coaxially arranged outside the anode cylinder and the cylindrical inner conductor, and there is an annular cavity coaxially between the cylindrical outer 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 cavity is radially coupled to a sector-shaped waveguide cavity through the coupling slots; N / 2 of the sector-shaped inserts are arranged between the cylindrical outer shell and the anode cylinder, and the annular cavity is divided into N / 2 sector-shaped waveguide cavities; The annular cavity between the cylindrical outer shell and the cylindrical inner conductor is a coaxial waveguide cavity, which realizes the mode transition and conversion from the sector-shaped waveguide cavity to the circular waveguide; The cylindrical outer 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 are connected by an annular microwave reflector.

2. The relativistic magnetron with an energy feedback structure according to claim 1, characterized in that, The coaxial waveguide cavity is successively a first coaxial section, a second coaxial section, and a third coaxial section from the input end to the output end; wherein, the inner and outer radii of the annular cavity of the second coaxial section gradually increase, and the inner and outer radii of the first coaxial section and the third coaxial section remain unchanged.

3. The relativistic magnetron with an energy feedback structure according to claim 1, wherein, The value of N is: 6 ≤ N ≤ 24, and N is an even number.

4. The relativistic magnetron with an energy feedback structure according to claim 3, characterized in that, The radius value range of the large circular waveguide section is 100 - 140 mm; the radius value range of the small circular waveguide section is 74 - 92 mm.

5. The relativistic magnetron with an energy feedback structure according to claim 4, characterized in that, The distance between the microwave reflector and the coaxial inner conductor is 10 - 60 mm.

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

7. A relativistic magnetron with an energy feedback structure according to claim 6, characterized in that, All components are made of stainless steel or graphite or titanium or copper as materials.

Images