Frequency agility relativistic magnetron based on dynamic seal axial tuning assembly

Abstract

The invention discloses a frequency agility relativistic magnetron based on a dynamic seal axial tuning assembly, and belongs to the technical field of high-power microwave sources. Comprising an anode cylinder, N anode blades, a vacuum chamber shell, a magnetofluid sealing assembly, N / 2 fan-shaped insertion pieces and a tuning assembly, the vacuum chamber shell is coaxially arranged outside the anode cylinder, and an annular vacuum chamber is formed between the vacuum chamber shell and the anode cylinder; an inner sleeve of the magnetofluid sealing assembly is connected with the anode cylinder, and an outer sleeve is connected with the vacuum chamber shell; the tuning assembly is arranged in the vacuum chamber. According to the invention, the axial movement of the tuning assembly is realized through the matching relation of the anode cylinder, the tuning assembly and the vacuum chamber shell, so that the sizes of the coupling slot and the fan-shaped waveguide cavity are changed, and the resonant frequency of the resonant cavity formed by the fan-shaped resonant cavity, the coupling slot and the fan-shaped waveguide cavity is changed; and finally, real-time frequency agility of the device in a high-vacuum state is realized.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of high-power microwave sources, and particularly relates to a frequency-agile relativistic magnetron based on dynamic sealing axial tuning. BACKGROUND

[0002] At present, high-power microwave technology is widely concerned by numerous scientists at home and abroad. In order to be suitable for more extensive high-power microwave application scenarios, high-power microwave systems are developing in the direction of compactness, broadband, operation intelligence and the like.

[0003] Among numerous high-power microwave sources, a relativistic magnetron has a significant advantage in overall compact design of the device. It mainly realizes the conversion of a pulsed direct-current electrostatic field into a pulsed high-frequency electromagnetic field through the energy interaction process of an electrostatic field-high-energy particle beam-high-frequency field. At present, a common tunable relativistic magnetron can only change the internal cavity structure under the premise of breaking the vacuum and then performing vacuum pumping. Repeatedly repeating this operation greatly reduces the work efficiency. Each time the vacuum is broken and pumped, the vacuum pump needs to be started preheating, stopped and waited, and the like, which wastes a lot of operation time, and this will cause certain damage to the vacuum pump. Even the existing relativistic magnetron design scheme capable of realizing frequency-agile under the vacuum state, due to the influence of the tuning structure, cannot guarantee a high vacuum degree (such as below 10e-5Pa) under the premise of compactness.

[0004] Magnetic fluid sealing is a kind of vacuum dynamic sealing technology based on magnetic fluid. At present, due to its high practicability, it is widely used in the mechanical field. The magnetic fluid in the gap of the mechanical structure to be sealed is controlled by a permanent magnet to realize high-vacuum sealing. Theoretically, the ultimate vacuum degree can reach below 10e-6Pa, and it has the characteristics of long service life and high performance. By designing a mechanical structure matched therewith, certain object movement can be realized under a high-vacuum state, and it does not need to be manually controlled and does not need to destroy the high-vacuum state inside.

[0005] At present, common frequency tuning schemes of relativistic magnetrons mainly include modifying the structure in the radial direction or the axial direction to change the internal resonant frequency, and finally realizing the tuning of the working frequency.

[0006] For example, a S-band frequency-agile relativistic magnetron is proposed in the article "Studies of the frequency-agile relativistic magnetron", which realizes the change of the resonant frequency by adjusting the small cavity radius in the radial direction of the sun-shaped structure. This way increases the radial radius in the radial direction, and since the tuning structure occupies a certain radial space, the magnetic field mechanism design becomes very complex, which to some extent increases the overall weight of the device.

[0007] A frequency-agile relativistic magnetron with axial tuning is proposed in "A Frequency-Agile Relativistic Magnetron With Axial Tuning", which adopts a full-cavity extraction structure and realizes frequency tuning by changing the length of the relativistic magnetron coupling slit in the axial direction, but there are still some problems in engineering to realize compactness.

[0008] In summary, the current frequency agile relativistic magnetron cannot realize intelligent frequency agile under high vacuum condition on the premise of compactness and light weight. SUMMARY

[0009] In view of the problems of insufficient compactness and inability to realize intelligent frequency agile under high vacuum condition in the prior art, the present application provides a frequency agile relativistic magnetron based on a dynamic sealing axial tuning assembly.

[0010] The technical scheme adopted by the present application is as follows:

[0011] A frequency agile relativistic magnetron based on a dynamic sealing axial tuning assembly, characterized in that it comprises an anode cylinder, N anode blades, a vacuum chamber shell, a magnetic fluid sealing assembly, N / 2 fan-shaped inserts and a tuning assembly.

[0012] The N anode blades are uniformly distributed on the inner wall of the middle part of the anode cylinder, and the adjacent anode blades form a fan-shaped resonant cavity; a coupling slit is formed on the outer side of the anode cylinder of the fan-shaped resonant cavity for microwave energy coupling.

[0013] The vacuum chamber shell is coaxially arranged outside the anode cylinder, and an annular vacuum chamber is formed therebetween, which is sequentially divided into a coaxial tuning section, a fan-shaped waveguide section and a coaxial output section from the input end to the output end.

[0014] The N / 2 fan-shaped inserts are uniformly distributed along the circumference in the fan-shaped waveguide section, dividing the annular vacuum chamber into N / 2 fan-shaped waveguide cavities; one fan-shaped waveguide cavity corresponds to the outer side of two adjacent coupling slits, and the microwave energy is extracted radially through the coupling slits to the fan-shaped waveguide cavities, and then integrated into one output in the coaxial output section.

[0015] The inner wall of the coaxial tuning section of the vacuum chamber shell is provided with threads; the tuning assembly is arranged in the coaxial tuning section and comprises an annular column part and N / 2 fan-shaped column tuning blades; the annular column part is matched with the annular vacuum chamber in shape, and the outer wall surface of the annular column part is provided with matched threads with the inner wall surface of the vacuum chamber shell; the N / 2 fan-shaped column tuning blades are matched with the fan-shaped waveguide cavity in shape, one end of each of the fan-shaped column tuning blades is connected with the annular column part, and the other end of each of the fan-shaped column tuning blades extends into the fan-shaped waveguide cavity; the tuning structure is moved leftward and rightward along the axial direction by relatively rotating the vacuum chamber shell and the anode cylinder, the coupling gap and the axial length of the fan-shaped waveguide cavity are adjusted, and thus the frequency agility of the relativistic magnetron is realized.

[0016] The magnetic fluid sealing assembly comprises an inner sleeve, an outer sleeve and magnetic fluid located between the inner sleeve and the outer sleeve; the inner sleeve is connected with the input end of the anode cylinder, and the outer sleeve is connected with the input end of the vacuum chamber shell, so that the vacuum chamber shell and the anode cylinder can be relatively rotated under the condition of ensuring the vacuum degree.

[0017] Preferably, the value of N is an even number greater than or equal to 6.

[0018] Preferably, the adjustable range of the axial length of the fan-shaped waveguide cavity is 0-60 mm.

[0019] Preferably, the materials of the anode cylinder, the anode blade, the vacuum chamber shell and the tuning assembly are titanium alloy.

[0020] Preferably, the inner sleeve is connected with the anode cylinder through a flange plate, and the outer sleeve is connected with the vacuum chamber shell through a flange plate.

[0021] Preferably, the connecting parts (flange plate connections) of each component are positioned by using positioning pins to ensure the coaxiality.

[0022] Preferably, the tolerance of the contact surface of each component is ±0.02 mm to achieve better electrical contact.

[0023] The beneficial effects of the present application are as follows:

[0024] 1. The present application adopts a full-cavity extraction structure, the microwave energy of adjacent resonant cavities is coupled into a fan-shaped waveguide cavity through a coupling gap, the fan-shaped TE 11 modes are combined to obtain a fan-shaped TE 11 mode, and then the fan-shaped TE 11 mode is combined into a coaxial TEM mode in the coaxial cavity and is output to the next link. Since the cutoff wavelength of the TEM mode is infinite, the size of the coaxial waveguide can be very compact, that is, the compactness of the device is also realized in the axial direction.

[0025] 2. This invention designs a method that uses a magnetohydrodynamic sealing assembly and a tuning assembly to rotate the inner sleeve, thereby driving the internal anode cylinder to rotate angularly. Through the cooperation between the anode cylinder, the tuning assembly, and the vacuum chamber shell, the tuning assembly can be moved axially, thereby changing the size of the coupling gap and the fan-shaped waveguide cavity, and thus changing the resonant frequency of the resonant cavity composed of the fan-shaped resonant cavity, the coupling gap, and the fan-shaped waveguide cavity, ultimately realizing real-time frequency agility of the device under high vacuum conditions. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the overall structure of the relativistic magnetron in an embodiment.

[0027] Figure 2 This is a cross-sectional view of the relativistic magnetron along the axial direction in an embodiment.

[0028] Figure 3 This is a schematic diagram of the relativistic magnetron vacuum harmonic mechanism in an embodiment.

[0029] Figure 4 This is a partial dimensioning diagram of the relativistic magnetron in an embodiment.

[0030] Figure 5 This is a schematic diagram illustrating the frequency agility performance of a relativistic magnetron in an embodiment. Explanation of reference numerals in the attached drawings: 1. Outer sleeve of the magnetohydrodynamic sealing assembly; 2. Inner sleeve of the magnetohydrodynamic sealing assembly; 3. Annular column section; 4. Sector-shaped resonant cavity; 5. Anode blade; 6. Vacuum chamber shell; 7. Sector-shaped insert; 8. Coaxial output structure; 9. Coupling gap; 10. Sector-shaped column tuning blade. Detailed Implementation

[0031] To make the objectives, technical solutions, and technical problems solved by this invention clearer, the invention will be further quantitatively described below in conjunction with the accompanying drawings and specific examples.

[0032] The frequency-agile relativistic magnetron of the dynamic seal axial tuning assembly provided in this embodiment operates in the L-band, such as... Figures 1-3 As shown, it includes an anode cylinder, six anode blades, a vacuum chamber shell, a magnetohydrodynamic sealing assembly, three sector inserts, and a tuning assembly.

[0033] The anode cylinder has a diameter Ф1 of 33.7 mm; the anode blade has a length L2 of 89 mm, an inner diameter Ф2 of 26.3 mm, and a corresponding central angle of 23°. Six anode blades are evenly distributed on the inner wall of the middle part of the anode cylinder, and a fan-shaped resonant cavity is formed between adjacent anode blades. A coupling gap with a length L3 of 89 mm and an angle of 35° is opened on the anode cylinder outside the fan-shaped resonant cavity for microwave energy coupling.

[0034] The inner diameter of the vacuum chamber shell is 47.5mm, and the coaxial tuning section is arranged outside the anode cylinder, and the annular vacuum chamber is formed between the coaxial tuning section and the anode cylinder, and the annular vacuum chamber is sequentially divided into the coaxial tuning section, the sector waveguide section and the coaxial output section from the input end to the output end.

[0035] The length of the sector-shaped insert piece is 89.5mm, and the three sector-shaped insert pieces are uniformly distributed in the sector waveguide section along the circumference to divide the annular vacuum chamber into three sector waveguide cavities, and the corresponding central angle of the sector waveguide cavity is 90°; the outer side of the adjacent two coupling slots corresponds to a sector waveguide cavity, and the microwave energy is extracted to the sector waveguide cavity through the coupling slot, and the sector TE 11 mode is obtained by combining, and then the coaxial TEM mode is obtained in the coaxial output section and is output.

[0036] The inner wall of the coaxial tuning section of the vacuum chamber shell is provided with threads; the tuning assembly is arranged in the coaxial tuning section and includes an annular column part and three sector column tuning blades; the length of the annular column part is 51mm, the inner and outer radii are matched with the shape of the annular vacuum chamber, and the outer wall surface of the annular column part and the inner wall surface of the vacuum chamber shell are provided with matched threads; the three sector column tuning blades are matched with the shape of the sector waveguide cavity, one end is connected with the annular column part, and the other end extends into the sector waveguide cavity; by relatively rotating the vacuum chamber shell and the anode cylinder, the tuning structure moves left and right along the axial direction, and the maximum moving distance is 60mm, so that the axial length of the coupling slot and the sector waveguide cavity is adjusted, and the frequency agility of the relativistic magnetron is realized.

[0037] The magnetic fluid sealing assembly includes an inner sleeve, an outer sleeve and a magnetic fluid between the inner sleeve and the outer sleeve; wherein the inner sleeve has the same inner diameter as the anode cylinder, the inner sleeve is connected with the input end of the anode cylinder through a flange, the outer sleeve is connected with the input end of the vacuum chamber shell through a flange, and a positioning pin is arranged at the connection position to realize high coaxiality; the magnetic fluid sealing assembly can enable the vacuum chamber shell and the anode cylinder to relatively rotate under the condition of ensuring the vacuum degree.

[0038] As shown in Figure 5 The present application can realize the axial relative movement of the sector column tuning blade by 60mm under the condition of high vacuum degree (10e-5Pa) and angular rotation of the magnetic fluid inner sleeve, the tuning range is 1.2GHz to 2.3GHz, and the frequency band output power is greater than 250MW; and when the relativistic magnetron works in the π mode, the phase difference of each sector resonant cavity is 180°, and a sector TE 11 mode can be obtained by combining adjacent resonant cavities. Since the cutoff wavelength of the TEM mode is infinite, the power capacity problem needs to be considered for the coaxial part, and the mode cutoff problem does not need to be considered, so the size of the coaxial waveguide can be very compact.

Claims

1. A frequency agile relativistic magnetron based on a dynamic seal axial tuning assembly, characterized in that, The device comprises an anode cylinder, N anode blades, a vacuum chamber shell, a magnetic fluid sealing assembly, N / 2 fan-shaped inserts, and a tuning assembly. The N anode blades are evenly distributed on the inner wall of the middle part of the anode cylinder, and the adjacent anode blades form a fan-shaped resonant cavity. The vacuum chamber shell is coaxially arranged outside the anode cylinder, and an annular vacuum chamber is formed between the two, which is divided into a coaxial tuning section, a fan-shaped waveguide section, and a coaxial output section from the input end to the output end. N / 2 fan-shaped inserts are evenly distributed in the fan-shaped waveguide section along the circumference, which divides the annular vacuum chamber into N / 2 fan-shaped waveguide cavities. The inner wall of the coaxial tuning section of the vacuum chamber shell is provided with threads, and the tuning assembly is arranged in the coaxial tuning section and comprises a ring-shaped column part and N / 2 fan-shaped column tuning blades. The ring-shaped column part is matched with the shape of the annular vacuum chamber, and the outer wall surface of the ring-shaped column part is provided with a matching thread with the inner wall surface of the vacuum chamber shell.

2. A frequency agile relativistic magnetron based on a dynamic seal axial tuning assembly as defined in claim 1, characterized in that, N / 2 fan-shaped column tuning blades are matched with the shape of the fan-shaped waveguide cavities, one end is connected with the ring-shaped column part, and the other end extends into the fan-shaped waveguide cavities.

3. A frequency agile relativistic magnetron based on a dynamic seal axial tuning assembly as claimed in claim 1 or 2, characterized in that, By relatively rotating the vacuum chamber shell and the anode cylinder, the tuning structure moves axially left and right, the axial length of the coupling gap fan-shaped waveguide cavity is adjusted, and the frequency of the relativistic magnetron is changed.

4. A frequency agile relativistic magnetron based on a dynamic seal axial tuning assembly as defined in claim 3, characterized in that, The magnetic fluid sealing assembly comprises an inner sleeve, an outer sleeve, and a magnetic fluid between the inner sleeve and the outer sleeve.

5. A frequency agile relativistic magnetron based on a dynamic seal axial tuning assembly as defined in claim 4, characterized in that, The inner sleeve is connected with the input end of the anode cylinder, and the outer sleeve is connected with the input end of the vacuum chamber shell, so that the vacuum chamber shell and the anode cylinder can be relatively rotated while ensuring the vacuum degree.

6. A frequency agile relativistic magnetron based on a dynamic seal axial tuning assembly as defined in claim 5, characterized in that, N is an even number greater than or equal to 6.

7. A frequency agile relativistic magnetron based on a dynamic seal axial tuning assembly as defined in claim 6, characterized in that, The axial length of the fan-shaped waveguide cavity can be adjusted in the range of 0-60mm. The materials of the anode cylinder, anode blades, vacuum chamber shell, and tuning assembly are titanium alloy. The inner sleeve is connected with the anode cylinder through a flange, and the outer sleeve is connected with the vacuum chamber shell through a flange. The connecting parts of each component are positioned by positioning pins to ensure coaxiality. The tolerance of the contact surface of each component is ±0.02mm.

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