CN115064428A - A coaxial magnetron using dielectric material as external cavity energy storage element and its application - Google Patents

Abstract

The invention relates to a coaxial magnetron taking a dielectric material as an external cavity energy storage element, which comprises a cathode arranged in the center and anode fan blades coaxial with the cathode; an inner cavity is formed between the cathode and the anode fan blade, and the anode fan blade and the outer ring form a coaxial outer cavity; and the outer cavity is filled with a medium to serve as an energy storage element. The coaxial magnetron using the medium to fill the outer cavity has the advantage that the volume of the outer cavity of the coaxial magnetron is reduced compared with that of the common coaxial magnetron, so that the applicable frequency band and the use scene of the coaxial magnetron can be widened; meanwhile, the cathode with a larger emission area can be used under the condition of ensuring that the whole size of the magnetron is not changed, so that higher output power can be obtained, and the performance of the magnetron is greatly improved.

Description

A coaxial magnetron using dielectric material as external cavity energy storage element and its application

technical field

The invention relates to a coaxial magnetron, in particular to a coaxial magnetron using a dielectric material as an external cavity energy storage element and its application.

Background technique

Magnetron is a common vacuum tube, its essence is a quadrature field oscillator, and it is a high-power microwave source in microwave technology. Compared with the klystron, the magnetron has the advantages of high efficiency, low operating voltage, simple structure, small size, light weight and low cost. At present, magnetrons have been widely used in defense, industry, agriculture, medical and other fields.

Coaxial magnetron is a common type of magnetron. In addition to having a cavity similar to ordinary magnetrons as an inner cavity, it also has a coaxial outer cavity; during application, through the frequency modulation cover plate The height can achieve the purpose of tuning the frequency. Compared with ordinary magnetrons, coaxial magnetrons have the characteristics of large output power, high efficiency, wide tuning range, good frequency stability, and long tube life. But due to the introduction of the coaxial outer cavity, the volume of the magnetron also becomes larger. The introduction of the coaxial outer cavity makes the volume of the coaxial magnetron generally larger, which leads to two problems: first, because the lower the frequency and the larger the size of the microwave device, the coaxial magnetron can only be used in general. It can be used in high frequency bands such as C and X, but cannot be used in low frequency bands such as S and L. Second, limited by the actual size and weight, the cathode emitting area of the coaxial magnetron is limited, which results in limited emitting current of the magnetron, and thus limited output power.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a coaxial magnetron with a dielectric material as an external cavity energy storage element, comprising a cathode arranged in the center, and an anode fan blade coaxial with the cathode; the cathode and the anode fan blade An inner cavity is formed between the anode fan blades and the outer ring to form a coaxial outer cavity;

The outer ring is the circular shell of the coaxial magnetron.

Wherein, the outer cavity is filled with a medium.

The coaxial magnetron is proposed to improve the stability of the magnetron, but in the prior art, a part of the compactness needs to be sacrificed. The design of the invention can improve the compactness of the coaxial magnetron and further reduce the size of the coaxial magnetron on the premise of ensuring the efficiency.

The main advantage of the coaxial magnetron is better stability, which is due to the fact that most of its energy is stored in the outer cavity. In the prior art, the outer cavity of the coaxial magnetron is a vacuum cavity surrounded by oxygen-free copper material, but the present invention proposes to use the cavity filled with the medium as the energy storage element of the coaxial magnetron. At this time, it is necessary to carry out microwave and electronic dynamics simulation of magnetron according to the electrical properties of the optional dielectric materials, and take the overall tube efficiency, output power, stability, etc. as the optimization goals, and iterate repeatedly to obtain various mechanical parameters, including cathode, The dimensions of the inner cavity and outer cavity, as well as the size and filling position of the medium material, etc., and then the actual sample tube design, trial production and testing are carried out, and after many optimizations and improvements, various mechanical parameters are finally determined.

Further, the upper end of the cathode is provided with an upper pole piece, and the lower end is provided with a lower pole piece.

Further, the inner cavity and the outer cavity are separated by a coupling seam between the inner and outer cavities.

The coupling slit is used for microwave coupling between the inner cavity and the outer cavity.

Further, the coaxial magnetron further includes a magnetron output port arranged on the outer ring.

Further, the coaxial magnetron further includes a tuning cover. Used to adjust the output power of the magnetron.

Further, the medium is an electric vacuum medium, preferably one or more of quartz glass, alumina ceramics (99% purity), diamond, alumina single crystal (artificial sapphire); especially quartz and ceramics are used When used as a medium, its filling effect is excellent; especially in combination with partial filling.

Further, all or part of the medium is filled in the outer cavity of the coaxial magnetron.

Preferably, the partial filling is outer filling. The outer filling specifically refers to the side of the outer cavity away from the cathode.

Wherein, the connection between the medium and the cavity is welding, clamping or chiseling.

The application of the coaxial magnetron in the fields of non-destructive testing, industrial flaw detection, medical treatment, well logging and the like.

In the prior art, the coaxial magnetron is proposed to improve the stability of the magnetron; however, a part of the compactness needs to be sacrificed. On the basis of optimizing the above technical features, the present invention can improve the compactness of the coaxial magnetron by rational design, and the size of the magnetron can be adjusted according to actual needs.

The medium material used in the present invention may be a single medium, a mixed medium, or a superposition of multiple mediums. The filling method of the medium in the outer cavity may be full filling or partial filling, including bottom filling, top filling, inner filling, outer filling, or a combination of the above.

Among them, the diameter of the cathode is preferably 20 to 40 mm. When a cathode of this size is used, ceramic and/or quartz glass is used as the medium for partial filling, and the effect is very ideal; especially, when the outer filling is used, the filling thickness is 3-5 mm.

The output power is most ideal when the following filling methods are used:

1. When the diameter of the cathode is about 24mm, the filling medium is alumina ceramics, the thickness is 3-4mm, and the outer filling method is adopted, and the output power of the coaxial magnetron is the largest. Suitable for smaller coaxial magnetrons.

2. When the diameter of the cathode is about 30mm, the filling medium is alumina ceramic, the thickness is 3mm, and the outer filling method is adopted, and the output power of the coaxial magnetron is the largest. For medium-sized coaxial magnetrons.

3. When the diameter of the cathode is about 36mm, the filling medium is quartz glass, the thickness is 5mm, and the outer filling method is adopted, and the output power of the coaxial magnetron is the largest. Suitable for slightly larger coaxial magnetrons.

The coaxial magnetron provided by the present invention uses a dielectric material as an external cavity energy storage element, by filling the coaxial external cavity with a suitable dielectric material, the volume of the coaxial external cavity can be greatly reduced, thereby effectively solving the problem of The following two questions.

First, the volume of the coaxial magnetron that uses the medium to fill the outer cavity is smaller than that of the conventional magnetron, so that in the low frequency band, the coaxial magnetron can also be used in applications with high anti-interference and high stability requirements. Therefore, the applicable frequency band and usage scenarios of the coaxial magnetron can be broadened.

Second, using a coaxial magnetron that fills the outer cavity with a medium can use a cathode with a larger emitting area while keeping the overall size of the magnetron unchanged, thereby achieving higher output power.

Description of drawings

1 is a schematic structural diagram of a coaxial magnetron provided in Embodiment 1;

2 is a schematic structural diagram of the coaxial magnetron provided by Embodiments 2 to 3;

3 is a schematic structural diagram of the coaxial magnetron provided by Embodiments 4 to 6;

4 is a schematic structural diagram of the coaxial magnetron provided in Embodiment 7;

In the figure: 1. Cathode; 2. Anode fan blade; 3. Inner cavity; 4. Coupling seam between inner and outer cavity; 5. Outer cavity; 6. Magnetron output port; 7. Tuning cover plate; 8. Upper pole shoe ; 9. Lower pole shoe; 10. Filling medium.

Detailed ways

The following examples are intended to illustrate the present invention, but not to limit the scope of the present invention.

Example 1

This embodiment provides a coaxial magnetron whose outer cavity is completely filled with quartz glass. As shown in FIG. 1 , it includes a cathode 1 arranged in the center, and an anode fan blade 2 coaxial with the cathode 1; An inner cavity 3 is formed between the anode fan blades 2, and a coaxial outer cavity 5 is formed between the anode fan blades 2 and the outer ring; the cover plate is provided with a tuning cover plate 7;

The outer cavity 5 is filled with quartz glass, and the filling method is full filling, that is, the medium fills the outer cavity 5 .

Wherein, the upper end of the cathode 1 is provided with an upper pole piece 8 , and the lower end is provided with a lower pole piece 9 .

The inner cavity 3 and the outer cavity 5 are separated by a coupling slit 4 between the inner and outer cavities.

Wherein, the coaxial magnetron further includes a magnetron output port 6 arranged on the outer ring.

This embodiment uses the same size cathode as a typical coaxial magnetron, but the outer diameter of the magnetron can be reduced to about 85mm.

Example 2

This embodiment provides a coaxial magnetron with alumina ceramic partially filling the outer cavity, as shown in FIG. 2 , including a cathode 1 arranged in the center, and an anode fan blade 2 coaxial with the cathode 1; the cathode 1 An inner cavity 3 is formed between the anode fan blade 2, the anode fan blade 2 and the outer ring form a coaxial outer cavity 5; the cover plate is provided with a tuning cover plate 7.

The outer cavity 5 is filled with 99% alumina ceramics, and the filling method is partial filling. Specifically, the medium is filled outside the outer cavity 5 with a thickness of about 3 mm.

Wherein, the upper end of the cathode 1 is provided with an upper pole piece 8 , and the lower end is provided with a lower pole piece 9 .

The inner cavity 3 and the outer cavity 5 are separated by a coupling slit 4 between the inner and outer cavities.

Wherein, the coaxial magnetron further includes a magnetron output port 6 arranged on the outer ring.

This embodiment uses the same size cathode as a typical coaxial magnetron, but the outer diameter of the magnetron can be reduced to about 85mm.

Example 3

This embodiment provides a coaxial magnetron in which alumina ceramics partially fills the outer cavity, as shown in FIG. 2 , the same as Embodiment 2 is filled with 99% alumina ceramics, the difference is that the thickness of the ceramics is about 4 mm. The corresponding magnetron outer diameter can be further reduced to 80mm.

Example 4

This embodiment provides a coaxial magnetron with a quartz glass partially filled outer cavity, as shown in FIG. 3 , comprising a cathode 1 arranged in the center, and an anode fan blade 2 coaxial with the cathode 1; An inner cavity 3 is formed between the anode fan blades 2, and a coaxial outer cavity 5 is formed between the anode fan blades 2 and the outer ring; a tuning cover plate 7 is arranged on the cover plate.

The outer cavity 5 is filled with quartz glass, and the filling method is partial filling. Specifically, the medium is filled outside the outer cavity 5 with a thickness of about 3 mm.

Wherein, the upper end of the cathode 1 is provided with an upper pole piece 8 , and the lower end is provided with a lower pole piece 9 .

The inner cavity 3 and the outer cavity 5 are separated by a coupling slit 4 between the inner and outer cavities.

Wherein, the coaxial magnetron further includes a magnetron output port 6 arranged on the outer ring.

This embodiment uses the same size magnetron outer diameter as the general coaxial magnetron, ie, 120 mm, but uses a larger size cathode, and the specific cathode diameter is about 30 mm.

Example 5

This embodiment provides a coaxial magnetron in which quartz glass partially fills the outer cavity, as shown in FIG. 3 .

Same as Example 4, quartz glass is used, the difference is that the thickness of the quartz glass is about 4 mm.

Same as Example 4, the outer diameter of the magnetron is the same as that of a general coaxial magnetron, namely 120 mm, and the difference is that the diameter of the cathode is about 36 mm.

Example 6

This embodiment provides a coaxial magnetron in which alumina ceramics partially fills the outer cavity, as shown in FIG. 3 .

The difference from Example 4 is that alumina ceramics are used to fill the outer side, and the thickness of the ceramics is about 3 mm.

Same as Example 4, the outer diameter of the magnetron is the same as that of a general coaxial magnetron, namely 120 mm, and the difference is that the diameter of the cathode is about 36 mm.

Example 7

This embodiment provides a coaxial magnetron in which quartz glass partially fills the outer cavity. As shown in FIG. 4 , it includes a cathode 1 arranged in the center, and an anode fan blade 2 coaxial with the cathode 1; An inner cavity 3 is formed between the anode fan blades 2, and a coaxial outer cavity 5 is formed between the anode fan blades 2 and the outer ring; a tuning cover plate 7 is arranged on the cover plate.

The outer cavity 5 is filled with quartz glass, and the filling method is full filling, that is, the medium fills the outer cavity 5 .

Wherein, the upper end of the cathode 1 is provided with an upper pole piece 8 , and the lower end is provided with a lower pole piece 9 .

The inner cavity 3 and the outer cavity 5 are separated by a coupling slit 4 between the inner and outer cavities.

Wherein, the coaxial magnetron further includes a magnetron output port 6 arranged on the outer ring. The size of the cathode in this embodiment is 36 mm, which is larger than that of a general coaxial magnetron, but its outer diameter is smaller than that of a general coaxial magnetron, about 100 mm.

Test comparison

The coaxial magnetrons provided in Examples 1 to 7, and the coaxial magnetrons (Reference Example 1 and Reference Example 2) that are not filled with medium in the outer cavity 5 are simulated by computer microwave and electron dynamics, and compared, The result is as follows:

It can be found that the fully filled quartz material used in Example 1 and the partially filled alumina ceramic material used in Example 2 have the same output power as the general coaxial magnetron without medium filling; but the outer diameter can be reduced by about 30%; It can be seen that filling the medium can make the coaxial magnetron more compact and smaller, and broaden the application market of the coaxial magnetron.

However, Examples 4 to 6 have the same dimensions as the coaxial magnetron without medium, but can use a larger diameter cathode, so the output power can be correspondingly improved, which greatly improves the performance of the magnetron. The outer diameter of the coaxial provided in Example 7 is reduced by 17%, while the output power of the magnetron is increased by 35%.

Although the present invention has been described in detail above with general description, specific embodiments and tests, some modifications or improvements can be made on the basis of the present invention, which is obvious to those skilled in the art . Therefore, these modifications or improvements made without departing from the spirit of the present invention fall within the scope of the claimed protection of the present invention.

Claims (10)

1. a coaxial magnetron with a dielectric material as an external cavity energy storage element, is characterized in that, comprises a cathode (1) arranged in the center, and an anode fan blade (2) coaxial with the cathode (1); An inner cavity (3) is formed between the cathode (1) and the anode fan blade (2), and the anode fan blade (2) and the outer ring form a coaxial outer cavity (5); Wherein, the outer cavity (5) is filled with a medium. 2 . The coaxial magnetron according to claim 1 , wherein an upper pole piece ( 8 ) is arranged at the upper end of the cathode ( 1 ), and a lower pole piece ( 9 ) is arranged at the lower end. 3 . 3 . The coaxial magnetron according to claim 1 , wherein the inner cavity ( 3 ) and the outer cavity ( 5 ) are separated by a coupling seam ( 4 ) between the inner and outer cavities. 4 . 4. The coaxial magnetron according to claim 1, characterized in that, further comprising a magnetron output port (6) arranged on the outer ring. 5. The coaxial magnetron according to claim 1, further comprising a tuning cover plate (7). 6 . The coaxial magnetron according to claim 1 , wherein the medium is selected from one or more of quartz glass, alumina ceramics, diamond, and alumina single crystal. 7 . 7. The coaxial magnetron according to claim 6, wherein the medium is fully or partially filled in the outer cavity of the coaxial magnetron; Preferably, the partial filling is outer filling. 8 . The coaxial magnetron according to claim 7 , wherein the diameter of the cathode is 20-40 mm; 8 . Preferably, the thickness of the partial filling is 3-5 mm. 9 . The coaxial magnetron according to claim 1 , wherein the connection between the medium and the cavity is welding, clamping or chiseling. 10 . 10. The application of the coaxial magnetron according to any one of claims 1 to 8 in the fields of non-destructive testing, industrial flaw detection, medical treatment, and well logging.

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