Relativistic magnetron for TE01 mode coaxial circular waveguide output

Abstract

The invention discloses a relativistic magnetron for coaxial circular waveguide output in a TE01 mode in the technical field of high-power microwave microsources. The relativistic magnetron with the TE01 mode coaxial circular waveguide output comprises a cathode, an inner cavity anode blade, an inner cavity anode outer wall, an outer cavity and a coaxial circular waveguide, the outer wall of the inner cavity anode is provided with periodic fan-shaped coupling gaps, the axial length of the outer wall of the inner cavity anode is larger than the length of the inner cavity anode blades, the outer cavity comprises fan-shaped resonant cavities and an excitation TE01 mode, the number of the fan-shaped resonant cavities corresponds to that of the inner cavity anode blades, the coaxial circular waveguide is directly connected with the outer cavity, and the output mode is TE01. According to the relativistic magnetron with the TE01 mode coaxial circular waveguide output, high-efficiency and high-power microwave energy output at the X wave band is achieved, the output mode is the TE01 mode, the efficiency and the power are improved, and the structure is more compact.

Description

Technical Field

[0001] The present invention relates to the technical field of high power microwave micro-sources, and more specifically to a TE 01 Relativistic magnetron with coaxial circular waveguide output mode. Background Art

[0002] High-power microwaves generally refer to electromagnetic waves with peak powers exceeding 100MW and frequencies between 1GHz and 300GHz. Their broad prospects in numerous fields, including defense, industry, and civil applications, have attracted widespread attention and significant research investment in many countries. Within the high-power microwave field, relativistic magnetrons, due to their compactness and high efficiency, play a crucial role among numerous high-power microwave sources. A relativistic magnetron is a high-power microwave generating device with a coaxial cathode and anode. During operation, a pulsed high voltage is applied between the cathode and anode, creating a radial electric field that is orthogonal to the axial magnetic field. Under the influence of the orthogonal electromagnetic field, an electron beam generated radially from the cathode surface drifts angularly under the influence of an external magnetic field. This angular drift of the electron beam excites electromagnetic oscillations in the anode's slow-wave structure, generating electromagnetic waves. The electron beam is in turn modulated by this excited electromagnetic wave, forming electron spokes. When the drift velocity of the electron spokes reaches synchronization with the phase velocity of the electromagnetic wave, the electron beam interacts with the high-frequency field, gradually amplifying the electromagnetic wave and generating high-power microwaves.

[0003] The current mainstream structures of relativistic magnetrons include full-cavity radial extraction and axial diffraction output structures, and their output modes are usually TEM mode, TM mode or mixed mode. However, although the external cavity of the traditional full-cavity radial extraction structure also uses a fan-shaped cavity, its working principle is to connect a fan-shaped cavity with two connected resonant cavities, and the TE mode at the anode blade resonant cavity is converted into the TM mode of the external cavity fan, and then output through a coaxial waveguide or other means; while the axial diffraction output structure can achieve TE in the X-band, 01 The output of the 1GW microwave energy can be realized, but the efficiency is only 22%, which is relatively low. 01 The mode is a common microwave mode. The electric and magnetic fields do not change along the angular direction. The field distribution is highly symmetrical. The power lines are all at the waveguide interface. At the same time, TE 01 The magnetic field on the waveguide wall has only a z-direction component, so the high-frequency current on the outer wall has only an angular component, and there is no longitudinal wall current. When the power is constant, the waveguide loss will decrease as the frequency increases, making it suitable for working in higher frequency bands; due to its low loss in microwave transmission, it is suitable for use in the feeder of high-power microwave antenna systems. At the same time, if the output mode of the relativistic magnetron is directly TE 01 , the complex high-power conversion part can be omitted, making the structure more compact, so it has TE 01Relativistic magnetrons with mode output have more advantages in practical applications. The traditional structure has the following problems: output mode limitation: the traditional radial extraction structure needs to convert the inner cavity TE mode into the outer cavity TM mode, resulting in efficiency loss; low efficiency: the existing X-band axial diffraction output structure has an efficiency of only 22%; complex structure: an additional mode conversion device is required to adapt to the TE 01 Therefore, it is urgent to design a TE 01 Relativistic magnetron with coaxial circular waveguide output mode. Summary of the Invention

[0004] The purpose of the present invention is to provide a TE 01 The relativistic magnetron with coaxial circular waveguide output solves the technical problems of output mode limitation, low efficiency and complex structure of traditional full-cavity radial extraction structure. It aims to achieve high efficiency and high power microwave energy output in the X-band by improving the structural design and some working principles of the relativistic magnetron, and the output mode is TE 01 mode, improve efficiency and power, and simplify structure.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] A TE 01 The relativistic magnetron with a coaxial circular waveguide output mode comprises a cathode, an inner cavity anode blade, an inner cavity anode outer wall, an outer cavity and a coaxial circular waveguide; the inner cavity anode outer wall is provided with a periodic fan-shaped coupling gap, the axial length of the inner cavity anode outer wall is greater than the length of the inner cavity anode blade, the outer cavity comprises a number of fan-shaped resonant cavities corresponding to the inner cavity anode blades, and excites TE 01 mode, the coaxial circular waveguide is directly connected to the external cavity, and the output mode is TE 01 .

[0007] Furthermore, the number of the cathode is one, including a cylindrical solid cathode and two cathode caps arranged on the solid cathode.

[0008] Furthermore, the number of the inner cavity anode blades is an even number, and the shape of the inner cavity anode blades is fan-shaped, forming a π-mode resonant cavity.

[0009] Furthermore, the outer wall of the inner cavity anode is adjacent to the inner cavity anode blade and is coaxial with the cathode. The outer wall of the inner cavity anode is provided with a coupling gap every other inner cavity anode blade as a period.

[0010] Furthermore, the axial center of the coupling gap coincides with the axial center of the cathode, and the angular position of the coupling gap is located at the angular center between two adjacent inner cavity anode blades.

[0011] Furthermore, the coaxial circular waveguide includes a coaxial cylindrical waveguide, and the coaxial circular waveguide is adjacent to the external cavity.

[0012] Furthermore, the fan-shaped resonant cavity is coaxial with the cathode, one side is closed, and the other side is completely open and connected to the coaxial circular waveguide, the axial center of the fan-shaped resonant cavity coincides with the axial center of the cathode and its angular center coincides with the angular center of the coupling gap.

[0013] By adopting the above technical solution, the present invention has the following advantages:

[0014] The present invention provides a TE 01 The relativistic magnetron with coaxial circular waveguide output mode realizes high efficiency and high power microwave energy output in the X-band by improving the structural design and some working principles of the relativistic magnetron, and the output mode is TE 01 Mode, TE 01 The mode has no longitudinal wall current, and the high-frequency loss is significantly reduced. In addition, the complex high-power mode conversion part can be omitted, making the structure more compact, so it has TE 01 The relativistic magnetron with mode output has more advantages in practical applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Other features, objects and advantages of the present invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings.

[0016] Figure 1 This is a schematic diagram of the overall structure of the XZ section of the present invention;

[0017] Figure 2 It is the XZ section structural parameter mark of the present invention;

[0018] Figure 3 It is the XY section structure parameter mark of the present invention;

[0019] Figure 4 The electric field distribution of the XY cross section when the present invention works normally;

[0020] Figure 5 The contour diagram of the electric field in the XZ section when the present invention is working normally;

[0021] Figure 6 The output of the PIC simulation result output port of a preferred embodiment of the present invention;

[0022] Figure 7 It is the frequency of the output port of the PIC simulation result of a preferred embodiment of the present invention.

[0023] Figure numerals: 1. cathode; 2. inner cavity anode blade; 3. inner cavity anode outer wall; 4. outer cavity; 5. coaxial circular waveguide. DETAILED DESCRIPTION

[0024] The technical solution of the present invention is described in detail below in conjunction with the drawings of the specification. The detailed features and advantages of the present invention are described in detail in the specific implementation mode. The content is sufficient to enable any technical personnel in this field to understand the technical content of the present invention and implement it accordingly. According to the description, claims and drawings disclosed in this specification, those skilled in the art can easily understand the relevant purposes and advantages of the present invention.

[0025] A TE 01 The overall XY cross-sectional structure diagram of the relativistic magnetron with coaxial circular waveguide output is as follows: Figure 1 As shown, it includes a cathode 1, an inner cavity anode vane 2, an inner cavity anode outer wall 3, an outer cavity 4, and a coaxial circular waveguide 5. The cathode 1 is a single piece, comprising a cylindrical solid cathode and two cathode caps disposed on the solid cathode. In a specific embodiment, the cathode 1 is a solid cathode with two cathode caps to prevent electrons from leaking to both sides of the cathode 1 and affecting overall operating efficiency. The electron emission surface is the entire cathode portion between the cathode caps, i.e., this portion also serves as the interaction region.

[0026] The inner cavity anode blade 2 has an even number of anode blades, and its shape is fan-shaped. In a specific embodiment, the inner cavity anode blade 2 adopts 16 fan-shaped blades.

[0027] A periodic, fan-shaped coupling slot is defined on the outer wall 3 of the inner cavity anode. The axial center of the coupling slot coincides with the axial center of the cathode 1, and the angular position of the coupling slot is located at the angular center between two adjacent inner cavity anode vanes. The axial dimension of the coupling slot must be larger than that of the inner cavity anode vanes 2 to prevent microwaves from being cut off. The coupling slot couples microwaves generated within the cavity to the outer cavity 4.

[0028] In a specific embodiment, the outer wall 3 of the inner cavity anode is adjacent to the inner cavity anode blade 2 and is coaxial with the cathode 1, but a fan-shaped coupling gap is opened every other inner cavity anode blade 2 as a cycle. The axial center of this coupling gap coincides with the axial center of the cathode 1, and its axial length is greater than the length of the inner cavity anode blade 2 to prevent the microwaves generated inside from being cut off and unable to be coupled to the outer cavity 4. The thickness of the outer wall of the inner cavity anode in this example is 4 mm.

[0029] The external cavity 4 includes multiple fan-shaped resonant cavities, which are used to excite the TE01 mode and couple the π mode of the internal cavity. The two are tightly coupled to stabilize the π mode and the output frequency. Its axial center is the same as the cathode and is close to the outer wall 3 of the inner cavity anode. The axial and radial dimensions need to be selected according to the π mode frequency of the inner cavity so that the TE01 mode excited by the external cavity is near it.

[0030] In a specific embodiment, the outer cavity 4 comprises a sector-shaped cavity half the number of the inner cavity anode blades 2, i.e., eight sector-shaped resonant cavities, coaxial with the cathode 1, with one side closed and the other side completely open to connect to the coaxial circular waveguide 5. In addition, the axial center of the sector-shaped resonant cavity coincides with the axial center of the cathode and its angular center coincides with the angular center of the coupling gap. When the relativistic magnetron is operating normally, the mode of the sector-shaped resonant cavity is TE 01 Rather than TE 10 , it is necessary to calculate the eigenmode of the external sector resonant cavity and obtain a frequency close to the working mode of the inner cavity.

[0031] The coaxial circular waveguide 5 includes a coaxial cylindrical waveguide, and is adjacent to the external cavity 4 for outputting microwaves. The inner diameter of the coaxial circular waveguide 5 is smaller than the inner diameter of the external cavity 4 to reduce the TE 01 mode cutoff frequency.

[0032] A TE 01 The working principle of the relativistic magnetron with coaxial circular waveguide output is as follows: the inner cavity works in π mode and the outer cavity 4 works in TE mode. 011 Mode, output coaxial circular waveguide 5 output TE 01 Mode microwave. The cathode part generates explosive electron emission under the external voltage, and after the electrons are clustered, electron spokes are formed, which work in the π mode, that is, the number of spokes is half the number of the inner cavity blades. The electric field mode of the inner cavity is the π mode. Its electric field characteristics are that the electric field phases in the fan-shaped resonant cavity between the separated inner cavity blades will be opposite, that is, the π mode electric field phases of every other fan-shaped resonant cavity are consistent; therefore, through the coupling gap of the outer wall 3 of the inner cavity anode and the fan-shaped resonant cavity directly connected to the coupling gap, these unidirectional electric fields can be coupled to the outer cavity 4, and by setting the outer diameter of the outer cavity reasonably, TE can be excited in the outer cavity. 01 mode; then, due to the axial position of the external cavity being directly connected to a coaxial circular waveguide 5, since the electric field phase in each sector resonant cavity is consistent, the mode can be directly converted into the TE in the coaxial circular waveguide by the coaxial circular waveguide 5 01 , to output microwaves.

[0033] The XZ section structure parameter marking and XY section structure parameter marking of a relativistic magnetron with TE01 mode coaxial circular waveguide output are as follows: Figure 2 、 Figure 3 The specific structural parameters and values ​​of the embodiment are shown in Table 1 below:

[0034] Table 1: XZ section structural parameters of the embodiment: and XY section structural parameters and values

[0035]

[0036] Due to the relativistic magnetron structure given by the present invention, a new external cavity working mode is proposed. In order to more clearly demonstrate its working principle, Figure 4 The electric field distribution of the XY cross section when the present invention is working normally is shown; Figure 5 The figure shows the contour line diagram of the electric field in the XZ section when the present invention works normally.

[0037] Figure 6 The output of the PIC simulation result output port of a preferred embodiment of the present invention is shown; Figure 7 The frequency of the PIC simulation result output port of a preferred embodiment of the present invention is shown. Figure 6 、 Figure 7 It can be seen that in a preferred embodiment, the results of PIC simulation are that at 550 kV and an axial confinement magnetic field of 0.28 T, the output frequency is 8.05 GHz, which is the X-band. The input is 3.1 GW, the output is 1.4 GW, the efficiency is 45%, and the output mode is TE. 01 .

[0038] Finally, it should be pointed out that although the present invention has been described with reference to the current specific embodiments, ordinary technicians in this technical field should realize that the above embodiments are only used to illustrate the present invention and are not used to limit the present invention. Various equivalent changes or substitutions can be made without departing from the concept of the present invention. Therefore, as long as the changes and modifications to the above embodiments are within the scope of the essential spirit of the present invention, they will fall within the scope of the claims of the present invention.

Claims

1. A TE 01 A relativistic magnetron with a coaxial circular waveguide output mode, characterized in that: The invention comprises a cathode, an inner cavity anode blade, an inner cavity anode outer wall, an outer cavity and a coaxial circular waveguide; the inner cavity anode outer wall is provided with a periodic fan-shaped coupling gap, the axial length of the inner cavity anode outer wall is greater than the length of the inner cavity anode blade, and the outer cavity comprises a number of fan-shaped resonant cavities corresponding to the number of the inner cavity anode blades, and excites TE 01 mode, the coaxial circular waveguide is directly connected to the external cavity, and the output mode is TE 01 .

2. A TE according to claim 1 01 A relativistic magnetron with a coaxial circular waveguide output mode, characterized in that: The number of the cathode is one, including a cylindrical solid cathode and two cathode caps arranged on the solid cathode.

3. A TE according to claim 1 01 A relativistic magnetron with a coaxial circular waveguide output mode, characterized in that: The number of the inner cavity anode blades is an even number, and the shape of the inner cavity anode blades is a fan shape, forming a π-mode resonant cavity.

4. A TE according to claim 1 01 A relativistic magnetron with a coaxial circular waveguide output mode, characterized in that: The outer wall of the inner cavity anode is closely adjacent to the inner cavity anode blade and is coaxial with the cathode. The outer wall of the inner cavity anode is provided with a coupling gap every other inner cavity anode blade as a cycle.

5. A TE according to claim 4 01 A relativistic magnetron with a coaxial circular waveguide output mode, characterized in that: The axial center of the coupling gap coincides with the axial center of the cathode, and the angular position of the coupling gap is located at the angular center between two adjacent inner cavity anode blades.

6. A TE according to claim 1 01 A relativistic magnetron with a coaxial circular waveguide output mode, characterized in that: The coaxial circular waveguide includes a coaxial cylindrical waveguide, and the coaxial circular waveguide is adjacent to the external cavity.

7. A TE according to claim 1 01 A relativistic magnetron with a coaxial circular waveguide output mode, characterized in that: The fan-shaped resonant cavity is coaxial with the cathode, one side is closed, and the other side is completely open and connected to the coaxial circular waveguide. The axial center of the fan-shaped resonant cavity coincides with the axial center of the cathode and its angular center coincides with the angular center of the coupling gap.

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