Coaxial spark switch of high-power pulse power system

Abstract

The invention provides a coaxial spark switch for a high-power pulse power system, which consists of three parts, namely a coaxial inner conductor, a coaxial outer conductor and a concave dielectric block, and realizes the function of efficiently transmitting microwave signals by reasonably designing the sizes of a transition section of the coaxial inner conductor and the concave dielectric block. Compared with a commonly used coaxial spark switch structure in which the medium is convex and the radius of the inner conductor is not changed, the inner concave medium block and the coaxial inner conductor transition section are adopted at the air-medium interface as a transition structure, and the impedance mutation of the air-medium interface in the coaxial waveguide is reduced, so that the coaxial spark switch structure is improved. Therefore, the signal reflection of the device is reduced. The device is suitable for a high-power pulse power system, and has the advantages of being easy to process and convenient to install.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of high-power pulse power system, and particularly relates to a coaxial spark switch of high-power pulse power system. BACKGROUND

[0002] The coaxial spark switch is an important component in the pulse power system, which not only determines the output characteristics of the high-power pulse power device, but also directly affects the normal operation of the entire high-power pulse power system. With the continuous development of the high-power pulse power system, the performance requirements of the coaxial spark switch are also continuously improved. The switch device is required not only to have fast discharge performance, but also to have large conduction energy. In order to obtain a high-power pulse power system with short pulse and large current, a switch device with small on-off loss and matched input and output impedance is particularly needed.

[0003] At present, the existing high-power pulse power system switch device is a coaxial spark switch with a constant inner conductor radius and an outer convex dielectric. Due to the impedance discontinuity at the air-dielectric interface, this structure usually has a large signal reflection. Therefore, in order to reduce the signal reflection, the present application adopts an inner concave dielectric block and a coaxial inner conductor gradual section as a transition structure at the air-dielectric interface, which can make the impedance of the air transmission section and the dielectric transmission section of the switch device the same, so as to match the impedance of the input and output ports, and further improve the performance of the switch device. SUMMARY

[0004] The technical problem to be solved by the present application is to provide a coaxial spark switch of high-power pulse power system for efficiently transmitting microwave signals.

[0005] The technical solution adopted by the present application to solve the above technical problem is as follows: a coaxial spark switch of high-power pulse power system, comprising a coaxial inner conductor, a coaxial outer conductor and an inner concave dielectric block; the coaxial inner conductor comprises a large-radius coaxial inner conductor, a small-radius coaxial inner conductor, and a coaxial inner conductor gradual section connecting the large-radius coaxial inner conductor and the small-radius coaxial inner conductor; the inner wall radius of the coaxial outer conductor is constant and greater than the outer wall radius of the large-radius coaxial inner conductor; the coaxial inner conductor and the coaxial outer conductor cooperate to form a coaxial waveguide for inputting and outputting microwave radio frequency signals through the two ends of the coaxial waveguide; the internal space of the coaxial waveguide is filled with air and then filled with the inner concave dielectric block; along the axial direction, the starting position of the air- inner concave dielectric block interface is the same as the starting position of the coaxial inner conductor gradual section, and the ending position of the air- inner concave dielectric block interface is the same as the ending position of the coaxial inner conductor gradual section.

[0006] According to the above scheme, the relative dielectric constant of the inner concave dielectric block is ; the outer wall radius of the large-radius coaxial inner conductor is a1, the outer wall radius of the coaxial inner conductor is a2, and the length of the coaxial inner conductor gradual change section is L1; the inner wall radius of the coaxial outer conductor is b1; and the following conditions are met: .

[0007] According to the above scheme, the impedance of the air transmission section and the dielectric transmission section of the coaxial waveguide is maintained at 50 ohm.

[0008] According to the above scheme, the large-radius coaxial inner conductor and the small-radius coaxial inner conductor are both cylindrical, and the coaxial inner conductor gradual change section is a truncated cone.

[0009] According to the above scheme, the coaxial outer conductor is a hollow cylinder.

[0010] According to the above scheme, the concave dielectric block is a hollow cylinder with a truncated cone removed at one end.

[0011] Further, the outer wall radius R of the concave dielectric block is equal to the inner wall radius b1 of the coaxial outer conductor, and the height H1 of the removed truncated cone is equal to the length L1 of the coaxial inner conductor gradual change section.

[0012] Further, the coaxial inner conductor is inserted into the center of the concave dielectric block, and the concave dielectric block is inserted into the center of the coaxial outer conductor.

[0013] The beneficial effects of the present application are: 1. The high-power pulse power system coaxial spark switch of the present application is composed of a coaxial inner conductor, a coaxial outer conductor and a concave dielectric block, and by reasonably designing the sizes of the coaxial inner conductor gradual change section and the concave dielectric block, the function of high-efficiency microwave signal transmission is realized.

[0014] 2. Compared with the commonly used dielectric outer convex, inner conductor radius unchanged type coaxial spark switch structure, the present application adopts a concave dielectric block and a coaxial inner conductor gradual change section as a transition structure at the air-dielectric interface, thereby reducing the impedance sudden change of the air-dielectric interface inside the coaxial waveguide, and reducing the signal reflection of the device.

[0015] 3. The present application is suitable for high-power pulse power systems, and the device has the advantages of easy processing and convenient installation.

[0016] Of course, any product implementing the present application does not necessarily need to achieve all the advantages described above at the same time. BRIEF DESCRIPTION OF DRAWINGS

[0017] In order to more clearly illustrate the technical solutions of the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings described below are only some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained without creative labor based on these drawings.

[0018] Figure 1 is a three-dimensional structural diagram of an embodiment of the present application.

[0019] Figure 2 is a front view of an embodiment of the present application.

[0020] Figure 3 is a reflection coefficient comparison diagram of an embodiment of the present application and a coaxial spark switch structure with unchanged inner conductor radius of the outer medium.

[0021] In the figure: 1. Coaxial inner conductor; 2. Coaxial outer conductor; 3. Inner recessed dielectric block; DETAILED DESCRIPTION In order to make the objects, technical solutions and advantages of the present application more clear, the following will further describe the present application in combination with the drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the present application, and are not used to limit the present application.

[0022] Embodiment 1 Referring to Figure 1 A high-power pulse power system coaxial spark switch includes a coaxial inner conductor, a coaxial outer conductor and an inner recessed dielectric block. The radius of the coaxial inner conductor gradually changes from large to small, including a radius gradually changing section, and the radius of the coaxial outer conductor is unchanged; the coaxial inner conductor and the coaxial outer conductor cooperate to form a coaxial waveguide structure, and the microwave signal is input and output through both ends of the coaxial waveguide; the internal space of the coaxial waveguide is filled with air and then filled with the inner recessed dielectric structure, and the air-medium interface is at the same position as the start position of the gradually changing radius of the coaxial inner conductor.

[0023] The coaxial inner conductor gradually changes from a large radius a1 to a small radius a2, and the length of the radius gradually changing section of the coaxial inner conductor is L1; the radius a1 of the coaxial inner conductor, the small radius a2 of the coaxial inner conductor after changing and the radius b1 of the coaxial outer conductor respectively satisfy the conditions: , wherein is the relative dielectric constant of the inner recessed dielectric block.

[0024] The inner recess type dielectric block is a cylindrical structure, one end of which is dug out as a cone; further, the center of the inner recess type dielectric block is axially penetrated by a coaxial inner conductor, and the outer surface is connected with a coaxial outer conductor; the radius R of the cylindrical structure of the inner recess type dielectric block is equal to the radius b1 of the coaxial outer conductor, and the height H1 of the dug-out cone is equal to the length L1 of the coaxial inner conductor gradual change section.

[0025] When the coaxial spark switch structure is transitioned from air filling to dielectric filling, the inner recess type dielectric block and the coaxial inner conductor gradual change section are used as transition structures to reduce the impedance mutation of the air-dielectric interface of the device, so as to achieve the purpose of reducing reflection.

[0026] In this embodiment, the sizes of the coaxial inner conductor gradual change section and the inner recess type dielectric block are reasonably designed, so that the function of efficiently transmitting microwave signals is realized.

[0027] Embodiment 2 The steps of this embodiment are the same as those of Embodiment 1, except that each structure is applied to a specific example. Specifically, it includes: As shown in Figure 1 A high-power pulsed power system coaxial spark switch includes a coaxial inner conductor, a coaxial outer conductor, and an inner recess type dielectric block. The coaxial inner conductor includes a large-radius coaxial inner conductor and a small-radius coaxial inner conductor, and the two structures are connected and transitioned by a coaxial inner conductor gradual change section; the coaxial inner conductor and the coaxial outer conductor cooperate to form a coaxial waveguide structure, and microwave radio frequency signals are input and output through the two ends of the coaxial waveguide; the internal space of the coaxial waveguide is transitioned from air filling to inner recess type dielectric structure filling, and the air-dielectric interface is the same as the start position of the gradual change of the radius of the coaxial inner conductor; Figure 2 It is a front view of the mode converter, and the size parameters of the mode converter are labeled.

[0028] In this embodiment, the radius b1 of the coaxial outer conductor is 68 mm, the radius of the coaxial inner conductor gradually changes from a1=29.56 mm to a2=14.3 mm, and the gradual change length L1 is 60 mm; the impedance of the air transmission section and the dielectric transmission section of the coaxial waveguide is kept at 50 ohm, the gradual change section of the air-dielectric interface can keep the continuity of the radio frequency electric field, and the reflection of the radio frequency signal is reduced.

[0029] Figure 3is a reflection coefficient comparison diagram of the coaxial spark switch structure of the embodiment and the coaxial spark switch structure with medium protruding outside and constant inner conductor radius. According to the diagram, the reflection coefficient of the coaxial spark switch structure of the embodiment is about-30dB at most in the working frequency band, while the reflection coefficient of the coaxial spark switch structure with medium protruding outside and constant inner conductor radius is about-10dB in the working frequency band. The reflection coefficient of the embodiment is improved by 20dB, and the reflection coefficient is smaller, which proves that the recessed medium block and the coaxial inner conductor gradual change section are used as the transition structure in the embodiment, the impedance mutation of the air-medium interface in the device can be reduced, and thus the signal reflection of the device can be reduced.

[0030] Compared with the coaxial spark switch structure with medium protruding outside and constant inner conductor radius commonly used, the recessed medium block and the coaxial inner conductor gradual change section are used as the transition structure at the air-medium interface in the embodiment, the impedance mutation of the air-medium interface in the coaxial waveguide is reduced, and thus the signal reflection of the device is reduced.

[0031] It should be understood that the size of the serial number of each step in the above embodiment does not mean the order of execution, and the execution order of each process should be determined according to its function and inherent logic, and should not constitute any limitation on the implementation process of the embodiment of the application.

[0032] It should be noted that according to the needs of implementation, each component described in the present application can be split into more components, or two or more components or parts of components can be combined into new components to achieve the purpose of the present application.

[0033] The above embodiments are only used to illustrate the design idea and characteristics of the present application, and the purpose is to enable those skilled in the art to understand the content of the present application and implement it, and the protection scope of the present application is not limited to the above embodiments. Therefore, any equivalent changes or modifications made according to the principles and design ideas disclosed in the present application are within the protection scope of the present application.

Claims

1. A coaxial spark switch for a high-power pulse power system, characterized in that: Includes coaxial inner conductor, coaxial outer conductor, and concave dielectric block; The coaxial inner conductor includes a large-radius coaxial inner conductor, a small-radius coaxial inner conductor, and a coaxial inner conductor transition section connecting the large-radius coaxial inner conductor and the small-radius coaxial inner conductor; The inner radius of the coaxial outer conductor remains unchanged and is larger than the outer radius of the large-radius coaxial inner conductor; The coaxial inner conductor and the coaxial outer conductor work together to form a coaxial waveguide, which is used to input and output microwave radio frequency signals through the two ends of the coaxial waveguide; the internal space of the coaxial waveguide is filled with air and then transitions to filled with a concave dielectric block; along the axial direction, the starting position of the interface between the air and the concave dielectric block is the same as the starting position of the transition section of the coaxial inner conductor, and the ending position of the interface between the air and the concave dielectric block is the same as the ending position of the transition section of the coaxial inner conductor.

2. The coaxial spark switch for a high-power pulse power system according to claim 1, characterized in that: Let the relative permittivity of the concave dielectric block be... The outer radius of the large-radius coaxial inner conductor is a1, the outer radius of the coaxial inner conductor is a2, and the length of the transition section of the coaxial inner conductor is L1; the inner radius of the coaxial outer conductor is b1; then the following conditions are satisfied: 。 3. The coaxial spark switch for a high-power pulse power system according to claim 1, characterized in that: The impedance of both the air transmission section and the dielectric transmission section of the coaxial waveguide is maintained at 50 ohms.

4. A coaxial spark switch for a high-power pulse power system according to claim 1, characterized in that: Both the large-radius and small-radius coaxial inner conductors are cylinders, and the transition section of the coaxial inner conductor is a truncated cone.

5. A coaxial spark switch for a high-power pulse power system according to claim 1, characterized in that: The coaxial outer conductor is a hollow cylinder.

6. A coaxial spark switch for a high-power pulse power system according to claim 1, characterized in that: The concave medium block is a hollow cylinder with a truncated cone cut out at one end.

7. A coaxial spark switch for a high-power pulse power system according to claim 6, characterized in that: The outer wall radius R of the concave dielectric block is equal to the inner wall radius b1 of the coaxial outer conductor, and the height H1 of the removed truncated cone is equal to the length L1 of the transition section of the coaxial inner conductor.

8. A coaxial spark switch for a high-power pulse power system according to any one of claims 4, 5, and 7, characterized in that: The inner conductor of the coaxial cable is inserted into the center of the concave dielectric block, and the concave dielectric block is inserted into the center of the outer conductor of the coaxial cable.

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