A compact axial output TE 11 Sunrise type magnetron

Abstract

The application discloses a compact axial output TE 11 sun-type magnetron of mode, and belongs to the field of vacuum electron devices in the microwave source technology. The sun-type magnetron of mode comprises a sun-type magnetron structure, a mode conversion structure and an output structure which are connected in sequence along an axial direction; the mode conversion structure comprises an axial mode conversion shell, a circular truncated cone cavity, N-2 extension cavities, one large gradual change extension cavity and one small gradual change extension cavity; the circular truncated cone cavity and the extension cavities are axial extensions of the magnetron cavities, and the large gradual change extension cavity and the small gradual change extension cavity are arranged on the two symmetrical sides in the axial mode conversion shell. The axial output magnetron can construct a large coherent array and realize power synthesis; the asymmetric structure of the large cavity and the small cavity in the sun-type magnetron is used to output the symmetrical TE 11 mode, which can be directly used for radiation, and the complicated and long mode converter is omitted; meanwhile, the axial size is greatly reduced by combining the sun structure and the diffraction structure, and the volume and weight of the array are reduced.

Description

Technical Field

[0001] This invention belongs to the field of vacuum electronic devices in microwave source technology, specifically relating to a compact axial output TE11 mode sunburst magnetron. Background Technology

[0002] With the application of high-power microwaves in radar, communications, and other fields, magnetrons, as a microwave source, have significant advantages over other vacuum electronic devices or solid-state devices due to their compact structure, high power, high efficiency, and low cost. Since the power of a single device is often limited, the high-efficiency magnetron frequency-locked phase-locked technology proposed by the University of Electronic Science and Technology of China, based on the principle of weak coupling between magnetrons, has driven the development of magnetrons towards large-scale arrays.

[0003] Frequency-locked and phase-locked (PLL) operation of magnetrons is achieved through weak coupling generated by radial coupling bridges between magnetrons. Traditional magnetrons output microwaves via one or more radial coupling ports. When constructing coherent arrays, this affects the number of array elements, thus reducing the array's output power. Therefore, based on radial coupling, array applications require magnetrons with axial output that are orthogonal to the coupling bridge. Currently, there is extensive research on relativistic magnetrons with axial output, but research on axial output magnetrons in the vacuum tube field is limited, and existing published literature shows that diffraction output structures are relatively long. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a compact axial output TE11 mode sunburst magnetron, which can be used in large-scale arrays to effectively reduce the size of the array.

[0005] To achieve the above-mentioned objectives, the technical solution adopted by this invention is as follows:

[0006] A compact axial output TE11 mode sunburst magnetron includes a sunburst magnetron structure 1, a mode conversion structure 2, and an output structure 3 connected axially in sequence.

[0007] The sunburst magnetron structure 1 includes: an anode structure 1-1 and a cathode structure 1-2;

[0008] The anode structure 1-1 includes blades 1-1-1 and anode cylinder 1-1-2. The blades extend from the inner circumferences of the anode cylinder with two different radii along the radial direction of the anode cylinder. Adjacent blades form resonant cavities of alternating sizes. The number of resonant cavities N = 2*(2*n+1), where n is an integer.

[0009] The cathode 1-2 includes a cathode end 1-2-1, an upstream cathode end cap 1-2-2, a hot cathode emitter 1-2-3, and a downstream cathode end cap 1-2-4, which are connected coaxially in sequence.

[0010] The mode transformation structure 2 is characterized in that it includes: an axial mode transformation shell 2-1, a frustum-shaped cavity 2-4, N-2 extension cavities 2-5, a large gradient extension cavity 2-2, and a small gradient extension cavity 2-3.

[0011] The upper bottom surface of the frustum-shaped cavity is connected to the interaction region of the sun-shaped magnetron structure, and the lower bottom surface is connected to the output structure 3.

[0012] The output structure 3 is a cylindrical waveguide, the radius of which is the same as the radius of the bottom surface of the frustum-shaped cavity.

[0013] The outer radius of the extended cavity is the same as the outer radius of the resonant cavity connected to it;

[0014] The large and small gradient extension cavities are symmetrically located on both sides inside the axial mode conversion housing. The large gradient extension cavity is an axially gradient extension of the large resonant cavity, and the small gradient extension cavity is an axially gradient extension of the small resonant cavity. The initial outer radius of both is the same as the outer radius of the resonant cavity connected to them. The outer radius is first linearly increased to be the same as the radius of the bottom surface of the frustum-shaped cavity, and then the radius is kept unchanged as it extends to the output structure.

[0015] Furthermore, the angle α between the generatrix of the frustum-shaped cavity and the axis ranges from 35° to 65°; the inclination angle β of the large gradient extension cavity... b The value range is 35°-90°, and the tilt angle β of the small gradually extending cavity is... s The value range is 35°-90°, and it satisfies β. b ≥α、β s ≥α、β b ≠β s .

[0016] Furthermore, the axial length of the hot cathode emitter is equal to or less than the axial length of the anode blade (L). c ≤L aWhen the axial length of the hot cathode emitter is equal to the axial length of the anode blade, the hot cathode emitter is located within the area surrounded by the anode blade; when the axial length of the hot cathode emitter is less than the axial length of the anode blade, the downstream cathode end cap is at least partially located within the area surrounded by the anode blade. For conventional magnetrons, the output is radial, so when a permanent magnet is used to provide a uniform axial magnetic field, the magnet can be directly and symmetrically installed along the magnetron's axis. However, when using an axial output magnetron, the installation of the permanent magnet becomes very difficult due to the presence of the mode-changing structure. Therefore, a structure is adopted where the end face of the hot cathode emitter connected to the downstream cathode end cap is on the same plane as one end of the anode, and the other end of the anode blade is located beyond the position of the hot cathode emitter. The axial length of the interaction space is equal to the length of the hot cathode emitter. In this case, the permanent magnet near the upstream cathode end cap can be installed outside the anode cylinder between the upstream cathode end cap and the mode-changing structure.

[0017] The beneficial effects of this invention are as follows:

[0018] This invention proposes a compact magnetron for axial extraction of the TE11 mode, based on efficient frequency and phase locking achieved through radial weak coupling between magnetrons. Its energy output direction is orthogonal to the radial direction, enabling the construction of large coherent arrays for power combining. Employing an asymmetric structure of large and small cavities in a sunburst magnetron, it outputs a symmetrical TE11 mode. The extracted TE11 mode can be directly used for radiation, eliminating the need for a complex and lengthy mode converter. Furthermore, by combining the sunburst and diffraction structures, its axial length is reduced from the traditional 1.6–3.2 times the operating wavelength to less than 0.62 times the operating wavelength, significantly reducing the axial dimension and thus the array's volume and weight. The design also considers the magnetic field design and installation, ensuring the practicality of this structure. Attached Figure Description

[0019] Figure 1 This is an overall side sectional view of an embodiment of the present invention;

[0020] Figure 2 This is a diagram of the cathode structure according to an embodiment of the present invention;

[0021] Figure 3 This is a cross-sectional view of the anode structure according to an embodiment of the present invention;

[0022] Figure 4 This is a front view of the diffraction structure according to an embodiment of the present invention;

[0023] Figure 5 This is a schematic diagram of the internal cavity structure of an embodiment of the present invention;

[0024] Figure 6 This is an electric field distribution diagram at the output port in an embodiment of the present invention;

[0025] Figure 7 This is the output signal power diagram of Embodiment 1 of the present invention;

[0026] Figure 8 This is the output signal spectrum diagram of Embodiment 1 of the present invention;

[0027] Figure 9 This is the output signal power diagram of Embodiment 2 of the present invention;

[0028] Figure 10 This is the output signal spectrum diagram of Embodiment 2 of the present invention. Detailed Implementation

[0029] The specific embodiments of the present invention are described below to enable those skilled in the art to understand the present invention. However, it should be understood that the present invention is not limited to the scope of the specific embodiments. For those skilled in the art, various changes are obvious as long as they are within the spirit and scope of the present invention as defined and determined by the appended claims. All inventions utilizing the concept of the present invention are protected.

[0030] Example 1

[0031] The compact axial output TE11 mode Sunrise magnetron of this embodiment operates at a frequency of 2.45 GHz. Figure 1 As shown, it includes a sunburst magnetron 1, a mode conversion structure 2, and an output structure 3.

[0032] The sunburst-type magnetron has 10 cavities, consisting of an anode structure 1-1 and a cathode structure 1-2 arranged coaxially. For example... Figure 2 As shown, the anode structure consists of anode blade 1-1-1 and anode cylinder 1-1-2. The anode blade radius Ra = 15 mm, the small resonant cavity radius Rsc = 34 mm, the large resonant cavity radius Rbc = 43 mm, and the subtended angle φ of each resonant cavity = 13°; Figure 3 As shown, the cathode radius Rc = 7.5 mm, and the length Lc of the hot cathode emitter 1-2-3 = 40 mm, which is the same as the axial length of the anode blade.

[0033] The mode transformation structure 2 includes: an axial mode transformation shell 2-1, a frustum-shaped cavity 2-4, eight extension cavities 2-5, a large gradient extension cavity 2-2, and a small gradient extension cavity 2-3.

[0034] The upper surface of the frustum-shaped cavity is connected to the interaction region of the sunburst magnetron structure, and the lower surface is connected to the output structure 3. The angle α between the generatrix of the frustum-shaped cavity and the axis is 50°. The output structure 3 is a cylindrical waveguide with a radius Ro = 91.5 mm. The outer radius of the extension cavity is the same as the outer radius of the resonant cavity connected to it. The large and small gradient extension cavities are symmetrically arranged on both sides inside the axial mode conversion housing, such as... Figure 4 As shown; wherein, the large gradient extension cavity is an axially gradient extension of the large resonant cavity, and the small gradient extension cavity is an axially gradient extension of the small resonant cavity. Both have the same initial outer radius as the resonant cavity connected to them. First, the outer radius is linearly increased until it is the same as the radius of the lower base of the frustum-shaped cavity, and then it extends to the output structure while maintaining the same radius. The tilt angle of the large gradient extension cavity is βb = 58°, and the tilt angle of the small gradient extension cavity is βs = 62.3°.

[0035] The length L of the mode conversion structure 2 is 64.2 mm, which is about half of the working wavelength. This reduces the axial length of the mode conversion structure 2 from the traditional 1.6 to 3.2 times the working wavelength to less than 0.62 times the working wavelength, greatly reducing the axial length.

[0036] A compact axial output TE11 mode magnetron was implemented using the above scheme. Simulation results... Figure 6-8 It can be seen that under the conditions of working voltage of 46kV, axial magnetic field of 0.204T, output mode of TE11, microwave output power of 1.8MW, working frequency of 2.45GHz, anode current of 84A, and corresponding power conversion efficiency of 47%.

[0037] Example 2

[0038] Keeping other parameters unchanged in Example 1, the anode height is increased to La = 50 mm, and the length of the hot cathode emitter 1-2-3, Lc = 40 mm, is less than the axial length of the anode blade.

[0039] A compact axial output TE11 mode magnetron was implemented using the above scheme. Simulation results... Figure 9-10 It can be seen that under the conditions of working voltage of 46kV, axial magnetic field of 0.204T, output mode of TE11, microwave output power of 1.1MW, working frequency of 2.4GHz, anode current of 78A, and corresponding power conversion efficiency of 31%.

Claims

1. A compact axial output TE 11 The mode of the sunburst magnetron includes a sunburst magnetron structure 1, a mode conversion structure 2, and an output structure 3 connected axially in sequence. The sunburst magnetron structure 1 includes: Anode structure 1-1 and cathode structure 1-2; The anode structure 1-1 includes blades 1-1-1 and anode cylinder 1-1-2. The blades extend from the inner circumferences of the anode cylinder with two different radii along the radial direction of the anode cylinder. Adjacent blades form resonant cavities of alternating sizes. The number of resonant cavities N = 2*(2*n+1), where n is an integer. The cathode structure 1-2 includes a cathode end 1-2-1, an upstream cathode end cap 1-2-2, a hot cathode emitter 1-2-3, and a downstream cathode end cap 1-2-4 connected coaxially in sequence. Its features are, The mode transformation structure 2 includes: an axial mode transformation shell 2-1, a frustum-shaped cavity 2-4, N-2 extension cavities 2-5, a large gradient extension cavity 2-2, and a small gradient extension cavity 2-3. The upper bottom surface of the frustum-shaped cavity is connected to the interaction region of the sun-shaped magnetron structure, and the lower bottom surface is connected to the output structure 3. The output structure 3 is a cylindrical waveguide, the radius of which is the same as the radius of the bottom surface of the frustum-shaped cavity. The outer radius of the extended cavity is the same as the outer radius of the resonant cavity connected to it; The large and small gradient extension cavities are symmetrically located on both sides inside the axial mode conversion housing. The large gradient extension cavity is an axially gradient extension of the large resonant cavity, and the small gradient extension cavity is an axially gradient extension of the small resonant cavity. The initial outer radius of both is the same as the outer radius of the resonant cavity connected to them. The outer radius is first linearly increased to be the same as the radius of the bottom surface of the frustum-shaped cavity, and then the radius is kept unchanged as it extends to the output structure.

2. A compact axial output TE as described in claim 1 11 The sunburst magnetron of the mode is characterized by, The angle α between the generatrix and the axis of the frustum-shaped cavity ranges from 35° to 65°; the inclination angle β of the large gradient extension cavity... b The value range is 35°-90°, and the tilt angle β of the small gradually extending cavity is... s The value range is 35°-90°, and it satisfies β. b ≥α、β s ≥α、β b ≠β s .

3. A compact axial output TE as described in claim 2 11 The sunburst magnetron of the mode is characterized by, The axial length of the hot cathode emitter is equal to or less than the axial length of the anode blade; when the axial length of the hot cathode emitter is equal to the axial length of the anode blade, the hot cathode emitter is located within the area surrounded by the anode blade; when the axial length of the hot cathode emitter is less than the axial length of the anode blade, the downstream cathode end cap is at least partially located within the area surrounded by the anode blade.

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