Vacuum capacitor and radio frequency matcher

Abstract

Provided in the present invention are a vacuum capacitor and a radio frequency matcher. The vacuum capacitor comprises a housing assembly, a magnetic suspension driving coil set, a magnetic suspension mover, a connection member, a shielding member, a movable electrode and a fixed electrode. The housing assembly is arranged in the direction of an axis, a closed vacuum chamber being formed in the housing assembly, and the magnetic suspension mover, the connection member, the shielding member, the movable electrode and the fixed electrode being all accommodated in the vacuum chamber. The shielding member divides the vacuum chamber into a first area and a second area, the movable electrode being movably arranged in the first area in the direction of the axis, the fixed electrode being fixedly arranged in the first area, the magnetic suspension mover being movably arranged in the second area in the direction of the axis, and the connection member movably passing through the shielding member in the direction of the axis and being separately connected to the magnetic suspension mover and the movable electrode. The magnetic suspension driving coil set is wound around the outside of the housing assembly corresponding to the second area, and the magnetic suspension driving coil set is used for driving the magnetic suspension mover and, by means of the connection member, driving the movable electrode to move in the direction of the axis.

Description

Vacuum capacitors and RF matching devices Technical Field

[0001] The present invention relates to the technical field of semiconductor devices, and in particular to a vacuum capacitor and a radio frequency matcher. Background Art

[0002] In some RF matchers, vacuum capacitors that can transmit high power and adjust capacitance are required to match impedance. Existing vacuum capacitors adjust capacitance by adjusting the spacing between electrodes. In order to adjust the position of the electrodes, bellows are often provided to balance vacuum sealing and electrode mobility. However, the mechanical life of the bellows is limited, and the speed response of the bellows is slow, which will affect the capacitance adjustment response speed of the vacuum capacitor. In addition, the vacuum inside the vacuum capacitor forms a pressure difference with the external normal pressure, so that when the movable electrode moves away from the fixed electrode, it has to overcome a relatively large atmospheric pressure resistance, which will also affect the capacitance adjustment response speed of the vacuum capacitor.

[0003] Summary of the Invention

[0004] The object of the present invention is to provide a vacuum capacitor and a radio frequency matching device to solve the problems of short life and slow response speed of existing vacuum capacitors.

[0005] In order to solve the above technical problems, the present invention provides a vacuum capacitor, which includes: a housing assembly, a magnetic levitation drive coil assembly, a magnetic floater, a connector, a shielding member, a movable electrode, and a fixed electrode;

[0006] The housing assembly is arranged along an axis, and a sealed vacuum chamber is formed inside the housing assembly; the magnetic float, the connecting member, the shielding member, the movable electrode, and the fixed electrode are all accommodated in the vacuum chamber;

[0007] Along the axis, the shielding member divides the vacuum chamber into a first area and a second area; the movable electrode is movably disposed in the first area along the axis, the fixed electrode is fixedly disposed in the first area, the magnetic float is movably disposed in the second area along the axis, and the connecting member movably penetrates the shielding member along the axis and is respectively connected to the magnetic float and the movable electrode;

[0008] The magnetic levitation drive coil assembly is wound around the exterior of the housing assembly corresponding to the second area, and is used to drive the magnetic float to move along the axis, and drive the movable electrode to move along the axis through the connecting member;

[0009] The vacuum capacitor comprises a movable electrode lead-out electrode, a fixed electrode lead-out electrode and a shield lead-out electrode, and the movable electrode lead-out electrode, the fixed electrode lead-out electrode and the shield lead-out electrode are connected to the movable electrode, the fixed electrode and the shielding member respectively.

[0010] Optionally, the vacuum capacitor further comprises a flexible electrode lead-out member provided in the first region; one end of the flexible electrode lead-out member is connected to the movable electrode, and the other end is connected to the housing assembly, and the end of the flexible electrode lead-out member connected to the housing assembly is configured as the movable electrode lead-out electrode;

[0011] Wherein, the flexible electrode lead-out member has a degree of freedom of deformation along the direction of the axis.

[0012] Optionally, the flexible electrode lead-out member is a hollow sheet-like member having an inner hole, through which the connecting member passes; the inner periphery of the sheet-like member is connected to the movable electrode, and the outer periphery of the sheet-like member is connected to the shell assembly.

[0013] Optionally, the shell assembly includes two end covers, one end cover is electrically connected to the shielding member, and the other end cover is electrically connected to the fixed electrode; the end cover electrically connected to the shielding member is configured as the shielding lead-out pole, and the end cover electrically connected to the fixed electrode is configured as the fixed electrode lead-out pole.

[0014] Optionally, the vacuum capacitor also includes a first guide assembly; the first guide assembly includes a guide rod and a guide sleeve arranged along the direction of the axis, one of the guide rod and the guide sleeve is arranged on the movable electrode, and the other is arranged on the shell assembly; the guide rod is movably inserted into the guide sleeve along the direction of the axis, and the guide sleeve is used to limit the position of the guide rod along the direction perpendicular to the axis.

[0015] Optionally, the vacuum capacitor further includes a second guide assembly; the second guide assembly includes a sleeve disposed on the shielding member, and the sleeve is used to limit the position of the connecting member along a direction perpendicular to the axis.

[0016] Optionally, the magnetic levitation drive coil group includes at least two coils, at least one of which is used to drive the magnetic float to move along the axis, and at least another coil is used to limit the position of the magnetic float along a direction perpendicular to the axis.

[0017] Optionally, the shielding member includes an electric field shielding layer and a magnetic field shielding layer along the axis direction, the electric field shielding layer is made of a high electrical conductivity material, and the magnetic field shielding layer is made of a high magnetic permeability material.

[0018] Optionally, the vacuum capacitor further includes a position detection module, and the position detection module is used to detect the position of the movable electrode along the axis.

[0019] In order to solve the above technical problems, the present invention further provides a radio frequency matching device, which includes the vacuum capacitor as described above.

[0020] In summary, in the vacuum capacitor and RF matching device provided by the present invention, the vacuum capacitor includes a housing assembly, a magnetic levitation drive coil assembly, a magnetic floater, a connector, a shielding member, a movable electrode, and a fixed electrode. The housing assembly is arranged along an axis and forms a sealed vacuum chamber therein. The magnetic floater, the connector, the shielding member, the movable electrode, and the fixed electrode are all accommodated in the vacuum chamber. The shielding member divides the vacuum chamber into a first region and a second region along the axis. The movable electrode is movably arranged in the first region along the axis, the fixed electrode is fixedly arranged in the first region, and the magnetic floater is movably arranged in the second region along the axis. The connector movably passes through the shielding member along the axis and is respectively connected to the magnetic floater and the movable electrode. The magnetic levitation drive coil assembly is wound around the exterior of the housing assembly corresponding to the second region. The magnetic levitation drive coil assembly is used to drive the magnetic floater to move along the axis and, through the connector, drive the movable electrode to move along the axis.

[0021] This configuration, on the one hand, places all moving components, except for the magnetic levitation drive coil assembly, within the vacuum chamber formed by the housing assembly. This eliminates the need for mechanically variable sealing components like bellows inside and outside the vacuum chamber, improving the reliability and service life of the vacuum capacitor. Furthermore, the moving components are unaffected by vacuum pressure differences, significantly reducing the driving force. Driven by magnetic force variations, the moving components' speed is greatly increased. Furthermore, the shielding element divides the vacuum chamber into a first and second region, further separating the electrode portion from the magnetic levitation drive portion, effectively preventing mutual interference between the two. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Those skilled in the art will appreciate that the accompanying drawings are provided for a better understanding of the present invention and do not constitute any limitation on the scope of the present invention.

[0023] FIG1 is a schematic diagram of a vacuum capacitor according to an embodiment of the present invention;

[0024] FIG2 is a schematic axial cross-sectional view of a vacuum capacitor according to an embodiment of the present invention;

[0025] FIG3 is a schematic diagram of a sheet member according to an embodiment of the present invention;

[0026] FIG4 is a schematic diagram of a fixed electrode according to an embodiment of the present invention;

[0027] FIG. 5 is a schematic diagram of a movable electrode according to an embodiment of the present invention.

[0028] In the attached figure:

[0029] 100-shell assembly; 110-vacuum chamber; 111-first area; 112-second area; 120-insulating tube; 130-end cover; 140-connecting terminal; 210-magnetic levitation drive coil group; 220-magnetic float; 300-connecting part; 400-shielding part; 510-movable electrode; 511-first substrate; 512-first electrode sheet; 513-connecting body; 520-fixed electrode; 521-second substrate; 522-second electrode sheet; 600-flexible electrode lead-out part; 610-sheet part; 620-inner hole; 700-first guide assembly; 710-guide rod; 720-guide sleeve; 800-second guide assembly; 810-shaft sleeve. DETAILED DESCRIPTION

[0030] To make the objects, advantages, and features of the present invention more clearly apparent, the present invention is further described below in conjunction with the accompanying drawings and specific embodiments. It should be noted that the drawings are all in a very simplified form and are not drawn to scale. They are only used to conveniently and clearly assist in illustrating the purposes of the embodiments of the present invention. In addition, the structures shown in the drawings are often part of the actual structure. In particular, different drawings may need to illustrate different focuses and sometimes use different scales.

[0031] As used in the present invention, the singular forms "a", "an" and "the" include plural objects, the term "or" is generally used to include the meaning of "and / or", the term "several" is generally used to include the meaning of "at least one", and the term "at least two" is generally used to include the meaning of "two or more". In addition, the terms "first", "second" and "third" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first", "second" and "third" may explicitly or implicitly include one or at least two of the features, "one end" and "the other end" as well as "proximal end" and "distal end" generally refer to two corresponding parts, which include not only endpoints. In addition, as used in the present invention, "installed", "connected", "connected", and one element is "set" on another element should be understood in a broad sense, usually only indicating that there is a connection, coupling, cooperation or transmission relationship between the two elements, and the connection, coupling, cooperation or transmission between the two elements can be direct or indirect through an intermediate element, and cannot be understood as indicating or implying the spatial position relationship between the two elements, that is, one element can be in any orientation such as inside, outside, above, below or on one side of another element, unless the content clearly indicates otherwise. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances. In addition, directional terms such as above, below, up, down, upward, downward, left, right, etc. are used relative to the exemplary embodiments as they are shown in the figures, with the upward or upper direction toward the top of the corresponding figure, and the downward or lower direction toward the bottom of the corresponding figure.

[0032] The present invention aims to provide a vacuum capacitor and a radio frequency matching device to solve the problems of short life and slow response speed of existing vacuum capacitors.

[0033] 1 to 5 , an embodiment of the present invention provides a vacuum capacitor, comprising: a housing assembly 100, a magnetic levitation drive coil assembly 210, a magnetic float 220, a connector 300, a shield 400, a movable electrode 510, and a fixed electrode 520; the housing assembly 100 is arranged along an axis A, and a sealed vacuum chamber 110 is formed therein; the magnetic float 220, the connector 300, the shield 400, the movable electrode 510, and the fixed electrode 520 are all accommodated in the vacuum chamber 110; along the axis A, the shield 400 divides the vacuum chamber 110 into a first region 111 and a second region 112; the movable electrode 510 is movably arranged in the first region 111 along the axis A, and the fixed electrode 520 is fixedly arranged in the first region 111. The magnetic float 220 is movably arranged in the second area 112 along the direction of the axis A, and the connecting member 300 is movably passed through the shielding member 400 along the direction of the axis A, and is respectively connected to the magnetic float 220 and the movable electrode 510; the magnetic levitation drive coil group 210 is wound around the outside of the shell assembly 100 corresponding to the second area 112, and the magnetic levitation drive coil group 210 is used to drive the magnetic float 220 to move along the direction of the axis A, and drive the movable electrode 510 to move along the direction of the axis A through the connecting member 300; wherein, the vacuum capacitor has a movable electrode lead-out pole, a fixed electrode lead-out pole and a shielding lead-out pole, and the movable electrode lead-out pole, the fixed electrode lead-out pole and the shielding lead-out pole are respectively connected to the movable electrode 510, the fixed electrode 520 and the shielding member 400.

[0034] With this configuration, all moving parts except the magnetic levitation drive coil assembly 210 are disposed in the vacuum chamber 110 formed by the housing assembly 100. Mechanically variable sealing components such as bellows are no longer required inside and outside the vacuum chamber 110, thereby improving the reliability and service life of the vacuum capacitor. Furthermore, the moving parts are not affected by the vacuum pressure difference, and the driving force is greatly reduced. Driven by magnetic force changes, the movement speed of the moving parts is greatly improved.

[0035] Please refer to Figure 2, and in combination with Figures 4 and 5, in one exemplary embodiment, the movable electrode 510 includes a first substrate 511 and a plurality of annular first electrode sheets 512 around an axis A, wherein the plurality of first electrode sheets 512 are coaxially arranged with spacing inside and outside and fixedly disposed on the first substrate 511. The fixed electrode 520 includes a second substrate 521 and a plurality of annular second electrode sheets 522 around an axis A, wherein the plurality of second electrode sheets 522 are coaxially arranged with spacing inside and outside and fixedly disposed on the second substrate 521. Furthermore, the first electrode sheets 512 and the second electrode sheets 522 are spaced apart in a direction perpendicular to the axis A, so that each first electrode sheet 512 does not directly contact the second electrode sheet 522. Preferably, the spacing between each first electrode sheet 512 and its adjacent second electrode sheet 522 is equal. Furthermore, the first electrode sheet 512 and the second electrode sheet 522 overlap in the direction of the axis A. It can be understood that based on the movement of the movable electrode 510 along the axis A, the capacitance between the movable electrode 510 and the fixed electrode 520 can be changed.

[0036] The inventors have found that in the prior art, a mechanical screw-nut assembly is often used to drive the movable electrode 510 to move. However, this requires the provision of a mechanically variable sealing component such as a bellows. On the one hand, this results in a limited mechanical life of the entire vacuum capacitor. On the other hand, in some application scenarios, such as when the capacitance of the vacuum capacitor needs to be adjusted quickly, mechanical screw-nut drive adjustment is difficult to achieve. The inventors have further found that if a magnetic field is used to drive the movable electrode 510 to move, although the problems of mechanical life and response speed can be solved, it will also bring about the problem of electromagnetic interference, resulting in insufficient reliability. Specifically, vacuum capacitors are generally used in scenarios for transmitting high-power radio frequency currents. Based on their working principle, it is not difficult to understand that there will be a strong electromagnetic field around the movable electrode 510 and the fixed electrode 520. Such an electromagnetic field will interfere with the magnetic field drive, and generate eddy current induced heating in static magnetic field materials such as magnets, resulting in low reliability.

[0037] Based on the above research, the present invention divides the vacuum chamber 110 into a first area 111 and a second area 112 in the axial direction by setting a shielding member 400, thereby separating the electrode part (including the movable electrode 510 and the fixed electrode 520) from the magnetic levitation drive part (including the magnetic levitation drive coil group 210 and the magnetic float 220), effectively overcoming the mutual interference between the two.

[0038] Preferably, the shielding member 400 includes an electric field shielding layer and a magnetic field shielding layer along the direction of the axis A. The electric field shielding layer is made of a high conductivity material. Here, the high conductivity material refers to a material with an electrical conductivity of not less than 10.0×10 6Materials with a high S / m, such as copper, aluminum, and other metals. High magnetic permeability materials refer to materials with a magnetic permeability of not less than 100, such as ferrite materials. The electric field shielding layer is used to isolate the high-frequency electromagnetic field on the movable electrode 510 and the fixed electrode 520, preventing it from being induced on the magnetic levitation drive coil assembly 210 and the magnetic float 220. The magnetic field shielding layer is used to isolate the low-frequency electric field and static magnetic field on the magnetic levitation drive coil assembly 210 and the magnetic float 220, preventing it from being induced on the movable electrode 510 and the fixed electrode 520. Optionally, the electric field shielding layer and the magnetic field shielding layer can be aligned in the direction of axis A or arranged at intervals.

[0039] Continuing with reference to FIG. 2 , optionally, in one exemplary embodiment, the housing assembly 100 includes an insulating tube 120 and two end caps 130 . The insulating tube 120 is disposed along the axis A, and the two end caps 130 are sealed and disposed at both ends of the insulating tube 120 along the axis A. The insulating tube 120 is made of, for example, ceramic and preferably has a cylindrical shape. The end caps 130 can be sealedly connected to the ends of the insulating tube 120 , thereby forming a vacuum chamber 110 inside the insulating tube 120 . Optionally, one end cap 130 is electrically connected to the shielding member 400 , and the other end cap 130 is electrically connected to the fixed electrode 520 . The end cap 130 electrically connected to the shielding member 400 is configured as the shielding lead-out electrode, and the end cap 130 electrically connected to the fixed electrode 520 is configured as the fixed electrode lead-out electrode. In one exemplary embodiment, an end cap 130 located on one side of the second region 112 (the upper end cap 130 in FIG. 2 ) is connected to the shield 400 via a conductor (not shown) disposed within the insulating tube 120 . The end cap 130 is preferably made of a metal material and serves as a shielding lead. During use, it can be grounded to further enhance the shielding effect. The end cap 130 located on one side of the first region 111 (the lower end cap 130 in FIG. 2 ) is electrically connected to the fixed electrode 520 . Alternatively, in some embodiments, the second substrate 521 of the fixed electrode 520 can be directly configured as an end cap 130 . In this case, the end cap 130 is preferably made of a metal material and also serves as the fixed electrode lead of the vacuum capacitor. In other embodiments, the housing assembly 100 is not limited to a combination of an insulating tube 120 and two end caps 130 . Alternatively, a combination of a closed-end cylinder and an end cap 130 can be employed. In this case, the closed end of the cylinder can also be considered an end cap 130 . This is not a limitation of the present invention.

[0040] Alternatively, in one exemplary embodiment, the magnetic float 220 is a magnet with a circular cross-section, such as a ring, cylinder, or disc. The connector 300 is a cylindrical insulator, such as a ceramic column, and is fixedly connected to the magnet. The shield 400 is preferably an annular plate with an inner hole. The connector 300 can pass through the inner hole of the shield 400 to connect to the first substrate 511 of the movable electrode 510. It should be noted that the thickness of the magnetic float 220 along the axis A should be less than the length of the second region 112 defined by the shield 400 along the axis A, so that the magnetic float 220 can move along the axis A within the second region 112. Preferably, the outer diameter of the annular shape of the magnetic float 220 is less than the inner diameter of the insulating cylinder 120. Optionally, the magnetic levitation drive coil assembly 210 includes at least two coils, at least one of which is used to drive the magnetic float 220 to move along the axis A, and at least one of which is used to limit the position of the magnetic float 220 in a direction perpendicular to the axis A. Specifically, the magnetic levitation drive coil assembly 210 not only drives the magnetic float 220 to move along the axis A but also limits its radial position (in a direction perpendicular to the axis A). This allows the magnetic float 220 to form a magnetic levitation configuration under the influence of the magnetic field of the magnetic levitation drive coil assembly 210 and move within the second region 112. This configuration reduces the movement resistance of the magnetic float 220 and further improves the response speed of capacitance adjustment. Furthermore, the radial positioning of the magnetic float 220 by the magnetic levitation drive coil assembly 210 can also reduce or eliminate friction between the guide rod 710 and the guide sleeve 720 of the first guide assembly 700 (described below).

[0041] Furthermore, the magnetic levitation drive coil group 210 is wound outside the wall of the insulating cylinder 120, and the length of the magnetic levitation drive coil group 210 along the direction of axis A should be greater than the thickness of the magnetic float 220 along the direction of axis A, and preferably covers the entire second area 112 to reliably drive the magnetic float 220 to move along the direction of axis A.

[0042] Referring to FIG. 2 and FIG. 3 , the vacuum capacitor optionally further includes a flexible electrode lead-out member 600 disposed in the first region 111 . One end of the flexible electrode lead-out member 600 is connected to the movable electrode 510 , and the other end is connected to the housing assembly 100 . The end of the flexible electrode lead-out member 600 connected to the housing assembly 100 is configured as the movable electrode lead-out terminal. The flexible electrode lead-out member 600 has a degree of freedom of deformation along the axis A. As will be appreciated, since the movable electrode 510 needs to move along the axis A within the vacuum chamber 110 , and in some scenarios, even rapidly reciprocate, the movable electrode 510 needs to be led out to serve as a lead-out terminal of the vacuum capacitor. This embodiment decouples the axially movable movable electrode 510 from the fixed housing assembly 100 by disposing the flexible electrode lead-out member 600 in the first region 111 , thereby achieving electrical connection to the movable electrode 510.

[0043] Preferably, the flexible electrode lead-out member 600 is a hollowed-out sheet-like member 610, which further includes an inner hole 620, through which the connector 300 passes. The inner periphery of the sheet-like member 610 is connected to the movable electrode 510, preferably fixedly connected, while the outer periphery of the sheet-like member 610 is connected to the housing assembly 100, preferably fixedly connected. In some embodiments, the connector 300 can be movably passed through the inner hole 620; in other embodiments, the connector 300 can also be fixedly connected to the sheet-like member 610 after passing through the inner hole 620. In an alternative exemplary embodiment, the housing assembly 100 includes a connecting terminal 140, which is, for example, fixedly mounted on the side wall of the insulating tube 120 and penetrates the side wall of the insulating tube 120. The outer periphery of the sheet-like member 610 is connected to the connecting terminal 140, so that the connecting terminal 140 and the movable electrode 510 are electrically conductive. At this time, the connecting terminal 140 serves as the movable electrode lead of the vacuum capacitor. As shown in FIG3 , the hollow shape of the sheet 610 can include a plurality of circumferentially discontinuous arcs. Of course, FIG3 is only an example of the hollow shape of the sheet 610 and is not intended to be limiting.

[0044] Preferably, the outer contour of the sheet 610 is the same as the inner wall shape of the insulating tube 120, for example, a circular shape. This allows the sheet 610 to be snugly connected to the inner wall of the insulating tube 120. In this case, the sheet 610 not only serves as an electrical connection but also acts as a radial limiter for the movable electrode 510. Specifically, the first substrate 511 of the movable electrode 510 includes a connector 513 extending along the axis A. The connector 513 may be cylindrical, for example, with one end distal from the first electrode sheet 512 fixedly connected to the edge of the inner hole 620. With this configuration, since the sheet 610 has the freedom to deform along the axis A but not in a direction perpendicular to the axis A, the connector 513 effectively supports and limits the radial position of the first substrate 511, thereby facilitating radial stability of the movable electrode 510.

[0045] Furthermore, the provision of the sheet member 610 can also reduce the parasitic inductance of the electrical connection of the movable electrode 510 and can be used to conduct the heat generated by the RF current in the movable electrode 510 to the insulating tube 120 for heat dissipation, for example, through the connecting terminal 140.

[0046] Please continue to refer to Figure 2. Optionally, the flexible electrode lead-out member 600 includes at least two sheet members 610, and the at least two sheet members 610 are arranged at intervals along the direction of the axis A. Preferably, the aperture of the inner hole 620 of the sheet member 610 away from the movable electrode 510 is smaller than the aperture of the inner hole 620 of the sheet member 610 close to the movable electrode 510. Of course, in other embodiments, the apertures of the inner holes 620 of at least two sheet members 610 can also be the same, and the present invention is not limited to this. The provision of at least two sheet members 610 further improves the reliability of the lead-out connection and further improves the radial limiting effect on the movable electrode 510.

[0047] Optionally, the vacuum capacitor further includes a first guide assembly 700. The first guide assembly 700 includes a guide rod 710 and a guide sleeve 720 disposed along the axis A. One of the guide rod 710 and the guide sleeve 720 is disposed on the movable electrode 510, and the other is disposed on the housing assembly 100. The guide rod 710 is movably disposed in the guide sleeve 720 along the axis A and is constrained by the guide sleeve 720 in a direction perpendicular to the axis A. In an alternative embodiment, one end of the guide sleeve 720 along the axis A is fixedly disposed on the first substrate 511 of the movable electrode 510, while the other end of the guide sleeve 720 is free and faces away from the connector 300. One end of the guide rod 710 along the axis A is fixedly disposed on the end cap 130 of the housing assembly 100, while the other end of the guide rod 710 is free and faces the connector 300 and movably penetrates the guide sleeve 720. Preferably, the outer contour shape of the guide rod 710 and the inner contour shape of the guide sleeve 720 are adapted to each other, so that the guide rod 710 can only move in the guide sleeve 720 along the direction of the axis A, and cannot move radially. Thus, the setting of the guide rod 710 and the guide sleeve 720 plays a radial limiting role on the movable electrode 510, which is beneficial to the radial stability of the movable electrode 510. Optionally, the guide rod 710 and the guide sleeve 720 are both made of insulating material, such as ceramic. In other embodiments, the guide rod 710 may be set on the first substrate 511 of the movable electrode 510, and the guide sleeve 720 may be fixedly set on the end cover 130 of the shell assembly 100. The principle is similar, and those skilled in the art can understand and replace the configuration based on the existing technology.

[0048] Optionally, the vacuum capacitor further includes a second guide assembly 800 ; the second guide assembly 800 includes a sleeve 810 disposed on the shielding member 400 . The sleeve 810 is used to limit the position of the connector 300 in a direction perpendicular to the axis A. In one exemplary embodiment, the inner diameter of the sleeve 810 matches the outer diameter of the connector 300 , allowing the connector 300 to move only along the axis A and being restrained by the sleeve 810 in a direction perpendicular to the axis A, thereby limiting radial displacement. In this case, the shielding member 400 not only separates the first region 111 from the second region 112 , achieving a shielding function, but also provides support and radially limits the connector 300 .

[0049] Preferably, the magnetic float 220, the connector 300, the shield 400, the sleeve 810, the movable electrode 510, the fixed electrode 520, the guide rod 710, and the guide sleeve 720 are all coaxially arranged along the axis A. The magnetic float 220, the connector 300, and the movable electrode 510 constitute a moving component. Along the direction of the axis A, there are four radial limits between the entire moving component and the insulating cylinder 120 from top to bottom, namely:

[0050] 1. The magnetic levitation drive coil assembly 210 limits the radial position of the magnetic float 220 through the magnetic field;

[0051] 2. The shaft sleeve 810 limits the radial position of the connector 300;

[0052] 3. The sheet member 610 limits the radial position of the first substrate 511 through the connector 513;

[0053] 4. The guide rod 710 and the guide sleeve 720 limit the radial position of the first substrate 511.

[0054] Based on these radial limitations, it is ensured that the movable electrode 510 only has the degree of freedom along the direction of the axis A and will not deflect in the radial direction, thereby effectively ensuring the reliability of the vacuum capacitor.

[0055] Optionally, the vacuum capacitor further includes a position detection module (not shown), which is used to detect the position of the movable electrode 510 along the axis A. In a first embodiment, the position detection module includes an airtight optical perspective window provided on the insulating tube 120 and / or the end cover 130, through which the axial position of the movable electrode 510 can be directly detected. In a second embodiment, the insulating tube 120 as a whole has optical transmittance, and in this case, the insulating tube 120 is configured as a position detection module. In a third embodiment, the position detection module includes a Hall sensor provided outside the insulating tube 120, which can detect the axial position of the movable electrode 510. In a fourth embodiment, the position detection module includes a built-in RF chip provided on the movable electrode 510, which can wirelessly transmit its own position information to the outside, thereby obtaining the axial position of the movable electrode 510.

[0056] Based on the vacuum capacitor described above, an embodiment of the present invention further provides a radio frequency matching device, which includes the vacuum capacitor described above. As for the structure and principle of other components of the radio frequency matching device, reference may be made to the prior art and will not be further described in the present invention.

[0057] In summary, in the vacuum capacitor and RF matching device provided by the present invention, the vacuum capacitor includes a housing assembly, a magnetic levitation drive coil assembly, a magnetic floater, a connector, a shielding member, a movable electrode, and a fixed electrode. The housing assembly is arranged along an axis and forms a sealed vacuum chamber therein. The magnetic floater, the connector, the shielding member, the movable electrode, and the fixed electrode are all accommodated in the vacuum chamber. The shielding member divides the vacuum chamber into a first region and a second region along the axis. The movable electrode is movably arranged in the first region along the axis, the fixed electrode is fixedly arranged in the first region, and the magnetic floater is movably arranged in the second region along the axis. The connector movably passes through the shielding member along the axis and is respectively connected to the magnetic floater and the movable electrode. The magnetic levitation drive coil assembly is wound around the exterior of the housing assembly corresponding to the second region. The magnetic levitation drive coil assembly is used to drive the magnetic floater to move along the axis and, through the connector, drive the movable electrode to move along the axis. This configuration, on the one hand, places all moving components, except for the magnetic levitation drive coil assembly, within the vacuum chamber formed by the housing assembly. This eliminates the need for mechanically variable sealing components like bellows inside and outside the vacuum chamber, improving the reliability and service life of the vacuum capacitor. Furthermore, the moving components are unaffected by vacuum pressure differences, significantly reducing the driving force. Driven by magnetic force variations, the moving components' speed is greatly increased. Furthermore, the shielding element divides the vacuum chamber into a first and second region, further separating the electrode portion from the magnetic levitation drive portion, effectively preventing mutual interference between the two.

[0058] It should be noted that the above embodiments can be combined with each other. The above description is only a description of the preferred embodiments of the present invention and does not limit the scope of the present invention. Any changes and modifications made by ordinary technicians in the field of the present invention based on the above disclosure are within the scope of protection of the present invention.

Claims

1. A vacuum capacitor, characterized in that: It includes: a shell assembly, a magnetic levitation drive coil group, a magnetic floater, a connecting piece, a shielding piece, a movable electrode and a fixed electrode; The housing assembly is arranged along an axis, and a sealed vacuum chamber is formed inside the housing assembly; the magnetic float, the connecting member, the shielding member, the movable electrode and the fixed electrode are all accommodated in the vacuum chamber; Along the direction of the axis, the shielding member divides the vacuum chamber into a first area and a second area; the movable electrode is movably disposed in the first area along the direction of the axis, the fixed electrode is fixedly disposed in the first area, the magnetic float is movably disposed in the second area along the direction of the axis, and the connecting member movably penetrates the shielding member along the direction of the axis and is respectively connected to the magnetic float and the movable electrode; The magnetic levitation drive coil group is wound around the outside of the housing component corresponding to the second area, and the magnetic levitation drive coil group is used to drive the magnetic floater to move along the direction of the axis, and drive the movable electrode to move along the direction of the axis through the connecting member; The vacuum capacitor comprises a movable electrode lead-out electrode, a fixed electrode lead-out electrode and a shield lead-out electrode, and the movable electrode lead-out electrode, the fixed electrode lead-out electrode and the shield lead-out electrode are connected to the movable electrode, the fixed electrode and the shielding member respectively.

2. The vacuum capacitor according to claim 1, characterized in that: The vacuum capacitor further comprises a flexible electrode lead-out piece arranged in the first region; one end of the flexible electrode lead-out piece is connected to the movable electrode, and the other end is connected to the housing assembly, and the end of the flexible electrode lead-out piece connected to the housing assembly is configured as the movable electrode lead-out pole; Wherein, the flexible electrode lead-out member has a degree of freedom of deformation along the direction of the axis.

3. The vacuum capacitor according to claim 2, characterized in that: The flexible electrode lead-out member is a hollow sheet-like member, and the sheet-like member also has an inner hole, and the connecting member passes through the inner hole; the inner periphery of the sheet-like member is connected to the movable electrode, and the outer periphery of the sheet-like member is connected to the shell assembly.

4. The vacuum capacitor according to claim 1, characterized in that: The shell assembly includes two end covers, one of which is electrically connected to the shielding member, and the other end cover is electrically connected to the fixed electrode; the end cover electrically connected to the shielding member is configured as the shielding lead-out pole, and the end cover electrically connected to the fixed electrode is configured as the fixed electrode lead-out pole.

5. The vacuum capacitor according to claim 1, characterized in that: The vacuum capacitor also includes a first guide assembly; the first guide assembly includes a guide rod and a guide sleeve arranged along the direction of the axis, one of the guide rod and the guide sleeve is arranged on the movable electrode, and the other is arranged on the shell assembly; the guide rod is movably inserted into the guide sleeve along the direction of the axis, and the guide sleeve is used to limit the position of the guide rod along the direction perpendicular to the axis.

6. The vacuum capacitor according to claim 1, characterized in that: The vacuum capacitor further comprises a second guide assembly; the second guide assembly comprises a sleeve disposed on the shielding member, the sleeve being used to limit the position of the connecting member along a direction perpendicular to the axis.

7. The vacuum capacitor according to claim 1, characterized in that: The magnetic levitation driving coil group includes at least two coils, at least one of which is used to drive the magnetic floater to move along the axis, and at least another coil is used to limit the position of the magnetic floater along a direction perpendicular to the axis.

8. The vacuum capacitor according to claim 1, characterized in that: The shielding member comprises an electric field shielding layer and a magnetic field shielding layer along the direction of the axis. The electric field shielding layer is made of a material with high electrical conductivity, and the magnetic field shielding layer is made of a material with high magnetic permeability.

9. The vacuum capacitor according to claim 1, characterized in that: The vacuum capacitor further comprises a position detection module for detecting a position of the movable electrode along the axis.

10. A radio frequency matching device, characterized in that: The invention comprises the vacuum capacitor according to any one of claims 1 to 9.

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