Cavity filter

Abstract

The application discloses a cavity filter, comprising: a cavity with an upper opening; a cover plate fixedly connected with the cavity and covering the upper opening, the cover plate having a through hole; a resonant rod at least partially located in the cavity, the resonant rod comprising a first connecting portion, a deformation portion and a second connecting portion arranged in sequence along an axial direction, the first connecting portion being fixedly connected with the cover plate and at least partially located in the through hole, the second connecting portion being adaptively connected with a debugging rod, the resonant rod having an inner hole penetrating through an upper surface of the resonant rod; and the debugging rod being connected with the second connecting portion and at least partially located in the inner hole. Axial movement of the debugging rod drives at least partial deformation of the deformation portion to change the distance between a lower surface of the resonant rod and a bottom surface of the cavity, so that the generation of metal debris and the like affecting performance can be effectively avoided.

Description

Technical Field

[0001] This application relates to the field of communication technology, and in particular to a cavity filter. Background Technology

[0002] In existing technologies, cavity filters typically include a cavity, a cover plate, a resonant rod, a tuning screw, a nut, and mounting screws. The tuning screw extends into the resonant rod through the nut and cover plate. During tuning, the threads of the three metal parts—tuning screw, cover plate, and nut—rub against each other, generating metal wires and dust that fall into the inner hole of the resonant rod. This can easily cause short circuits between the tuning screw and the resonant rod, or lead to poor intermodulation. The cover needs to be removed for cleaning, and after cleaning, tuning must be repeated, generating more metal wires and dust, creating a vicious cycle that results in high production costs and low production efficiency. Furthermore, the resonant rod is fixed to the bottom of the cavity by mounting screws, requiring machining at the mounting position. High-intermodulation products have extremely high requirements for the surface roughness and flatness of this machining, further increasing costs.

[0003] Therefore, it is necessary to provide a new cavity filter to solve the above problems. Summary of the Invention

[0004] The purpose of this application is to provide a cavity filter with a simple structure that can effectively avoid the generation of metal debris and other factors that affect performance, and has a low processing cost.

[0005] To achieve the above objectives, this application adopts the following technical solution:

[0006] A cavity filter, comprising: The cavity has an upper opening; A cover plate, fixedly connected to the cavity and covering the upper opening, the cover plate having a through hole; A resonant rod, at least partially located within the cavity, includes a first connecting portion, a deformable portion, and a second connecting portion arranged sequentially along the axial direction. The first connecting portion is fixedly connected to the cover plate and at least partially adapted to be located in the through hole. The second connecting portion is configured to be adapted to be connected to the adjustment rod. The first connecting portion, the deformable portion, and the second connecting portion have an inner hole on their radially inner sides, and the inner hole penetrates the upper surface of the resonant rod. The adjustment rod is connected to the second connecting part and is at least partially located in the inner hole. The axial movement of the adjustment rod causes at least part of the deformable part to undergo axial deformation, thereby changing the distance between the lower surface of the resonant rod and the bottom surface of the cavity.

[0007] As a further improvement to this application, the resonant rod is welded to the cover plate.

[0008] As a further improvement of the technical solution of this application, the cavity filter also includes a nut, the through hole has an internal thread, the outer wall of the first connecting part has an external thread, the nut is located on the side of the cover plate away from the cavity, and the first connecting part is threadedly connected to the through hole and the nut.

[0009] As a further improvement of this application, the inner wall of the second connecting part has an internal thread, the adjusting rod has an external thread, and the adjusting rod is threadedly connected to the second connecting part.

[0010] As a further improvement of this application, the resonant rod is at least partially located on the side of the cover plate away from the cavity.

[0011] As a further improvement of this application, the inner diameter of the deformable part is equal to the inner diameter of the first connecting part and greater than the inner diameter of the second connecting part.

[0012] As a further improvement to this application, the tuning rod and the resonant rod are integrally formed.

[0013] As a further improvement of this application, the wall thickness of the deformable part is less than the wall thickness of the first connecting part and the second connecting part.

[0014] As a further improvement of this application, the inner diameter of the deformable part is equal to the inner diameter of the first connecting part and greater than the inner diameter of the second connecting part, and the outer diameter of the deformable part is less than the inner diameter of the first connecting part and equal to the outer diameter of the second connecting part.

[0015] As a further improvement of the technical solution of this application, the resonant rod includes a rod body and a disk, the disk and at least a portion of the rod body are located in the cavity, the rod body is fixedly connected to the cover plate, and the outer diameter of the disk is larger than the outer diameter of the rod body.

[0016] As a further improvement of this application, the outer diameter of the deformable part is equal to the outer diameter of the first connecting part and smaller than the outer diameter of the second connecting part.

[0017] Compared to existing technologies, the cavity filter of this application offers the following advantages: By fixing the resonant rod to the cover plate, the number of components inside the cavity is reduced, simplifying the cavity structure. It eliminates the need for a resonant rod mounting platform and mounting holes, reducing various mold-related problems during die-casting and effectively minimizing intermodulation issues caused by screw connections. The adjustment rod is connected to the resonant rod, allowing for adjustment via axial movement, preventing the generation of metal debris that could affect performance. Furthermore, it adjusts the coupling position between the lower end of the resonant rod and the bottom of the cavity, resulting in a wider adjustable range. The same resonant rod can cover different nearby frequency bands, achieving material standardization. This cavity filter has a simple structure and low manufacturing cost. Utilizing the axial deformation of the resonant rod for tuning enables finer, more linear frequency adjustment and higher tuning resolution. Attached Figure Description

[0018] Figure 1 This is a cross-sectional structural diagram of a cavity filter according to a specific embodiment of this application; Figure 2 This is a cross-sectional structural schematic diagram of a cavity filter according to another specific embodiment of this application; Figure 3 This is a cross-sectional structural diagram of a cavity filter according to another specific embodiment of this application. Detailed Implementation

[0019] The exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. If several embodiments exist, features in these embodiments may be combined with each other without conflict. When the description refers to the drawings, unless otherwise stated, the same numbers in different drawings represent the same or similar elements. The descriptions in the following exemplary embodiments do not represent all embodiments consistent with the present invention; rather, they are merely examples of apparatuses, products, and / or methods consistent with some aspects of the present invention as set forth in the claims.

[0020] The terminology used in this invention is for the purpose of describing particular embodiments only and is not intended to limit the scope of protection of this invention. The singular forms “a,” “the,” or “the” as used in the specification and claims of this invention are also intended to include the plural forms unless the context clearly indicates otherwise.

[0021] It should be understood that the terms "first," "second," and similar words used in the specification and claims of this invention do not indicate any order, quantity, or importance, but are merely used to distinguish features. Similarly, the terms "an" or "a" do not indicate a quantity limitation, but rather indicate the presence of at least one. Unless otherwise stated, the terms "front," "back," "left," "right," "upper," "lower," and similar words appearing in this invention are for ease of explanation only and are not limited to a specific location or spatial orientation. The terms "comprising" or "including" are an open-ended expression, meaning that the element preceding "comprising" or "including" encompasses the element following "comprising" or "including" and its equivalents, but this does not preclude the element preceding "comprising" or "including" from also including other elements. In this invention, the term "several" means two or more.

[0022] Please see Figures 1 to 3 As shown in the figure, this application discloses a cavity filter, including a cavity 1, a cover plate 2, a resonant rod 3 and a tuning rod 4. The cavity 1 and the cover plate 2 cooperate to form a resonant cavity. The resonant rod 3 is located in the resonant cavity and is fixedly connected to the cover plate 2. The tuning rod 4 is fixedly connected to the resonant rod 3. The resonant rod 3 is tuned by axially moving the tuning rod 4 to drive the resonant rod 3 to deform.

[0023] The cavity 1 has an upper opening 11. A cover plate 2 is fixedly connected to the cavity 1 and covers the upper opening 11. The cover plate 2 has a through hole 21. The resonant rod 3 is at least partially located inside the cavity 1. The resonant rod 3 includes a first connecting part 31, a deformable part 32, and a second connecting part 33 arranged sequentially along the axial direction. The first connecting part 31 is fixedly connected to the cover plate 2 and is at least partially adapted to be located in the through hole 21. The second connecting part 33 is configured to be adapted to be connected to the adjustment rod 4. The radially inner sides of the first connecting part 31, the deformable part 32, and the second connecting part 33 have inner holes 30. The inner holes 30 of the first connecting part 31, the deformable part 32, and the second connecting part 33 are interconnected and penetrate the upper surface of the resonant rod 3 but not the lower surface of the resonant rod 3. The adjustment rod 4 is connected to the second connecting part 33 and is at least partially located in the inner hole 30.

[0024] This application achieves tuning by axially moving the tuning rod 4 to cause at least part of the deformable part 32 to undergo axial deformation, thereby changing the distance between the lower surface of the resonant rod 3 and the bottom surface of the cavity 1, i.e., fine-tuning the capacitance gap between the bottom of the resonant rod 3 and the bottom of the cavity 1. Compared with the screw-in / screw-out type, this tension / compression tuning method can achieve more precise and linear frequency adjustment and higher tuning resolution; moreover, the axial force of the tuning rod 4 acts directly on the second connecting part 33, and then the second connecting part 33 uniformly transmits the force to the easily deformable deformable part 32. The force transmission path is short and direct, the response is sensitive, and the ineffective loss of force is avoided.

[0025] The tuning rod 4 extends into the inner hole 30 of the resonant rod 3 and connects to the second connecting part 33 of the resonant rod 3. This design saves space at the top of the cavity filter, making the overall structure of the cavity filter more compact and facilitating miniaturization and high-density integration. Furthermore, it avoids problems such as thread wear, stripping, or loosening of the screw due to vibration that may occur in traditional screw tuning, improving the frequency stability of the cavity filter under long-term use or harsh environments. It also avoids the problem of metal debris generated by metal friction, thus improving tuning efficiency.

[0026] The resonant rod 3 is fixedly connected to the cover plate 2 to form a pre-assembled component. This component is then installed onto the cavity 1 as a whole, reducing the number of structural parts inside the cavity 1 and simplifying the assembly process of the cavity 1 structure and the cavity filter. There is no need to set up a resonant rod mounting platform and mounting holes inside the cavity 1, which can reduce various mold problems when the die-cast cavity 1 is opened and effectively reduce the inter-adjustment problems caused by screw connections, improve production efficiency, and help ensure the coaxiality and consistency between the resonant rod 3 and the cavity 1.

[0027] The resonant rod 3 includes a rod body 301 and a disk 302. The disk 302 and at least a portion of the rod body 301 are located inside the cavity 1. The rod body 301 is fixedly connected to the cover plate 2. The outer diameter of the disk 302 is larger than the outer diameter of the rod body 301. That is, the disk 302 is located near the bottom of the cavity 1. The first connecting part 31, the deformable part 32, and the second connecting part 33 are disposed on the rod body 301. With this arrangement, the rod body 301, the disk 302, and the bottom of the cavity 1 together form a capacitor structure. Increasing the outer diameter of the disk 302 can significantly increase the capacitance value.

[0028] In some embodiments, the resonant rod 3 is fixed to the cover plate 2 by welding. This arrangement ensures that the resonant rod 3 and the cover plate 2 remain absolutely fixed throughout the entire lifespan of the cavity filter, thereby guaranteeing the initial position accuracy and long-term stability of the resonant rod 3. Moreover, welding achieves a metallurgical bond between the resonant rod 3 and the cover plate 2, resulting in extremely low contact resistance. This provides an excellent RF grounding path for the resonant rod 3, effectively reducing insertion loss and improving the out-of-band rejection performance of the cavity filter. It also effectively seals the tiny gap between the resonant rod 3 and the cover plate 2, preventing external moisture, dust, etc., from entering the cavity 1 through this connection and affecting the electrical performance of the cavity filter or causing corrosion.

[0029] In some embodiments, the cavity filter further includes a nut 5. The through hole 21 of the cover plate 2 has internal threads, and the outer wall of the first connecting part 31 has external threads. The nut 5 is located on the side of the cover plate 2 away from the cavity 1. The first connecting part 31 is threadedly connected to the through hole 21 and the nut 5. That is, the resonant rod 3 and the cover plate 2 are fixed by a threaded connection and further locked by the nut 5. With this configuration, a reliable mechanical locking structure is formed between the resonant rod 3 and the cover plate 2, which can effectively prevent the resonant rod 3 from loosening due to vibration or temperature changes. The threaded connection allows for fine adjustment of the initial axial position of the resonant rod 3 during assembly, providing a certain degree of freedom for the initial debugging of the cavity filter. Moreover, it facilitates the disassembly of the resonant rod 3, improving the maintainability of the product and the recyclability of the parts.

[0030] In some embodiments, the inner wall of the second connecting part 33 has internal threads, and the adjusting rod 4 has external threads. The adjusting rod 4 is fixed by threaded connection with the second connecting part 33. This arrangement securely locks the adjusting rod 4 to the second connecting part 33 through the threaded connection. When the adjusting rod 4 is subjected to force, the force can be directly transmitted to the second connecting part 33 of the resonant rod 3, ensuring high efficiency and reliability of transmission. Furthermore, it facilitates the disassembly of the adjusting rod 4, improves the interchangeability of components and the maintainability of the product, and reduces maintenance costs.

[0031] In some embodiments, the resonant rod 3 is at least partially located on the side of the cover plate 2 away from the cavity 1, that is, the resonant rod 3 protrudes from the cover plate 2 at least partially through the through hole 21. This arrangement facilitates the exposure of the tuning rod 4 outside the cavity filter, allowing the operator to easily perform frequency tuning outside the cavity filter. It also reduces the risk of contact and friction with the cover plate 2 through the through hole 21, thereby effectively reducing the risk of wear and helping to ensure the sealing of the resonant cavity.

[0032] Furthermore, there is a certain distance between the adjustment rod 4 and the inner wall of the first connecting part 31 and the inner wall of the deformable part 32. That is, the adjustment rod 4 is a slender rod inserted into the inner hole 30 relative to the resonant rod 3.

[0033] In some embodiments, the inner diameter of the deformable portion 32 is equal to the inner diameter of the first connecting portion 31 and larger than the inner diameter of the second connecting portion 33. With this configuration, the inner diameters of the first connecting portion 31 and the deformable portion 32, which are closer to the upper opening than the second connecting portion 33, are equal, making it easier to process the resonant rod.

[0034] In some embodiments, the outer diameter of the deformable portion 32 is equal to the outer diameter of the first connecting portion 31 and smaller than the outer diameter of the second connecting portion 33. With this configuration, the outer diameters of the first connecting portion 31 and the deformable portion 32, which are closer to the upper opening, are equal relative to the second connecting portion 33, making it easier to process the resonant rod 3.

[0035] In some embodiments, the tuning rod 4 and the resonant rod 3 are integrally formed. Further, the tuning rod 4 and the resonant rod 3 are processed into one piece using a powder molding process. This configuration reduces processing difficulty compared to a threaded connection; it also fundamentally eliminates the risks of thread loosening and fatigue fracture at weld points. Since there is no mechanical connection interface between the tuning rod 4 and the resonant rod 3, when an axial push or pull force is applied to the tuning rod 4, the force can be transmitted to the deformation part 32 instantly and without loss, resulting in extremely fast tuning response. The movement of the tuning rod 4 is purely axial, without involving complex rotational friction, thus effectively avoiding the problem of screw loosening due to thread wear, improving operational stability, and simultaneously avoiding the problem of metal debris generated by metal-to-metal friction, thereby improving tuning efficiency.

[0036] Powder molding is a highly efficient process suitable for mass production. For cavity filters, which are widely used in communication equipment, this process can significantly shorten the production cycle, reduce the overall cost per unit part, and ensure product consistency and yield. Moreover, powder molding is a near-net-shape forming technology, and the molded parts require very little subsequent processing. It has high material utilization, effectively reduces material waste, and thus lowers costs.

[0037] In some embodiments, the wall thickness of the deformable portion 32 is less than that of the first connecting portion 31 and the second connecting portion 33. Furthermore, the deformable portion 32 forms a thin-walled structure. This configuration minimizes the wall thickness of the deformable portion 32, ensuring that when the resonant rod 3 is subjected to axial force, the stress is concentrated to the maximum extent in the deformable portion 32, guaranteeing reliable tuning functionality. The thinner wall thickness also makes the deformable portion 32 more prone to deformation, meaning that the operator only needs to apply a smaller force to achieve the desired frequency change, making tuning operation more effortless. Moreover, the thinner the wall thickness, the greater the deformation per unit axial force, resulting in higher sensitivity to minute displacements of the tuning rod 4 and enabling a wider frequency adjustment range.

[0038] In some embodiments, the inner diameter of the deformable portion 32 is equal to the inner diameter of the first connecting portion 31 and greater than the inner diameter of the second connecting portion 33, while the outer diameter of the deformable portion 32 is smaller than the inner diameter of the first connecting portion 31 and equal to the outer diameter of the second connecting portion 33. This configuration ensures that the wall thickness of the deformable portion 32 is less than the wall thickness of the first connecting portion 31 and the second connecting portion 33, while simultaneously making the inner diameter of the deformable portion 32 equal to the inner diameter of the first connecting portion 31 and the outer diameter equal to the outer diameter of the second connecting portion 33, thus facilitating the manufacturing and processing of the resonant rod 3.

[0039] Understandably, the purpose of local thin walls can be achieved by designing different inner and outer diameters of the first connecting part 31, the deformable part 32, and the second connecting part 33, in order to target cavity filters with different frequency ranges and different power capacities.

[0040] Please see Figure 1As shown in a specific embodiment of this application, the cavity filter includes a cavity 1, a cover plate 2, a resonant rod 3, and a tuning rod 4. The cavity 1 has an upper opening 11. The cover plate 2 is fixedly connected to the cavity 1 and covers the upper opening 11. The cover plate 2 has a through hole 21. The resonant rod 3 includes a first connecting part 31, a deformable part 32, and a second connecting part 33 arranged sequentially along the axial direction. The first connecting part 31 is welded to the cover plate 2 at the through hole 21. The tuning rod 4 is threadedly connected to the second connecting part 33. The wall thickness of the deformable part 32 is less than the wall thickness of the first connecting part 31 and the second connecting part 33. The inner diameter of the deformable part 32 is equal to the inner diameter of the first connecting part 31 and greater than the inner diameter of the second connecting part 33. The outer diameter of the deformable part 32 is less than the inner diameter of the first connecting part 31 and equal to the outer diameter of the second connecting part 33. By rotating the tuning rod 4, it causes relative axial movement with the resonant rod 3, thereby causing at least part of the deformable part 32 to undergo axial deformation, thereby changing the distance between the lower surface of the resonant rod 3 and the bottom surface of the cavity 1, thus achieving tuning.

[0041] Please see Figure 2 As shown, in another specific embodiment of this application, the cavity filter includes a cavity 1, a cover plate 2, a resonant rod 3, an adjustment rod 4, and a nut 5. The cavity 1 has an upper opening 11. The cover plate 2 is fixedly connected to the cavity 1 and covers the upper opening 11. The cover plate 2 has a through hole 21. The resonant rod 3 includes a first connecting part 31, a deformable part 32, and a second connecting part 33 arranged sequentially along the axial direction. The first connecting part 31 is threadedly connected to the cover plate 2 at the through hole 21. The nut 5 is threadedly connected and fixed to the first connecting part 31 outside the cavity 1. The adjustment rod 4 is threadedly connected to the second connecting part 33. The wall thickness of the deformable part 32 is equal to the wall thickness of the first connecting part 31 and less than the wall thickness of the second connecting part 33; the inner diameter of the deformable part 32 is equal to the inner diameter of the first connecting part 31 and greater than the inner diameter of the second connecting part 33; the outer diameter of the deformable part 32 is equal to the outer diameter of the first connecting part 31 and less than the outer diameter of the second connecting part 33. By rotating the tuning rod 4 to make it move axially relative to the resonant rod 3, at least part of the deformable part 32 will undergo axial deformation, thereby changing the distance between the lower surface of the resonant rod 3 and the bottom surface of the cavity 1, thus achieving tuning.

[0042] Please see Figure 3As shown, in another specific embodiment of this application, the cavity filter includes a cavity 1, a cover plate 2, a resonant rod 3, and a tuning rod 4. The cavity 1 has an upper opening 11. The cover plate 2 is fixedly connected to the cavity 1 and covers the upper opening 11. The cover plate 2 has a through hole 21. The resonant rod 3 includes a first connecting part 31, a deformable part 32, and a second connecting part 33 arranged sequentially along the axial direction. The first connecting part 31 is welded to the cover plate 2 at the through hole 21. The tuning rod 4 is integrally formed with the resonant rod 3, and the tuning rod 4 extends axially from the second connecting part 33 to the outside of the cavity 1. The wall thickness of the deformable part 32 is less than the wall thickness of the first connecting part 31 and the second connecting part 33; the inner diameter of the deformable part 32 is equal to the inner diameter of the first connecting part 31 and greater than the inner diameter of the second connecting part 33; the outer diameter of the deformable part 32 is less than the inner diameter of the first connecting part 31 and equal to the outer diameter of the second connecting part 33. By applying an axial force to the tuning rod 4 and transmitting it to the resonant rod 3, at least part of the deformable part 32 is driven to undergo axial deformation, thereby changing the distance between the lower surface of the resonant rod 3 and the bottom surface of the cavity 1, thus achieving tuning.

[0043] In summary, compared with existing technologies, the cavity filter of the present invention has the following advantages: By fixing the resonant rod 3 to the cover plate 2, the number of components inside the cavity 1 is reduced, simplifying the structure of the cavity 1. It eliminates the need for a resonant rod mounting platform and mounting holes, reducing various mold problems during die-casting cavity 1 mold opening and effectively reducing intermodulation problems caused by screw connections. The adjustment rod 4 is connected to the resonant rod 3, and adjustment is performed by axial movement of the adjustment rod 4, avoiding the generation of metal debris or other performance-affecting factors. Furthermore, it adjusts the coupling position between the lower end of the resonant rod 3 and the bottom of the cavity 1, resulting in a wider adjustable range. The same resonant rod 3 can cover different nearby frequency bands, achieving material standardization. This cavity filter has a simple structure and low processing cost. Utilizing the axial deformation of the resonant rod 3 for tuning enables finer, more linear frequency adjustment and higher tuning resolution.

[0044] The above embodiments are only used to illustrate the present invention and are not intended to limit the technical solutions described in the present invention. The understanding of this specification should be based on those skilled in the art. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still make modifications or equivalent substitutions to the present invention. All technical solutions and improvements that do not depart from the spirit and scope of the present invention should be covered within the scope of the claims of the present invention.

Claims

1. A cavity filter, characterized in that, include: The cavity has an upper opening; A cover plate, fixedly connected to the cavity and covering the upper opening, the cover plate having a through hole; A resonant rod, at least partially located within the cavity, includes a first connecting portion, a deformable portion, and a second connecting portion arranged sequentially along the axial direction. The first connecting portion is fixedly connected to the cover plate and at least partially adapted to be located in the through hole. The second connecting portion is configured to be adapted to be connected to the adjustment rod. The first connecting portion, the deformable portion, and the second connecting portion have an inner hole on their radially inner sides, and the inner hole penetrates the upper surface of the resonant rod. The adjustment rod is connected to the second connecting part and is at least partially located in the inner hole. The axial movement of the adjustment rod causes at least part of the deformable part to undergo axial deformation, thereby changing the distance between the lower surface of the resonant rod and the bottom surface of the cavity.

2. The cavity filter according to claim 1, characterized in that: The resonant rod is welded to the cover plate.

3. The cavity filter according to claim 1, characterized in that: The cavity filter also includes a nut, the through hole has an internal thread, the outer wall of the first connecting part has an external thread, the nut is located on the side of the cover plate away from the cavity, and the first connecting part is threadedly connected to the through hole and the nut.

4. The cavity filter according to claim 2 or 3, characterized in that: The inner wall of the second connecting part has an internal thread, the adjusting rod has an external thread, and the adjusting rod is threadedly connected to the second connecting part.

5. The cavity filter according to claim 2 or 3, characterized in that: The resonant rod is at least partially located on the side of the cover plate away from the cavity.

6. The cavity filter according to claim 3, characterized in that: The inner diameter of the deformable part is equal to the inner diameter of the first connecting part and greater than the inner diameter of the second connecting part.

7. The cavity filter according to claim 2, characterized in that: The tuning rod and the resonant rod are integrally formed.

8. The cavity filter according to claim 2 or 7, characterized in that: The wall thickness of the deformable part is less than the wall thickness of the first connecting part and the second connecting part.

9. The cavity filter according to claim 8, characterized in that: The inner diameter of the deformable part is equal to the inner diameter of the first connecting part and greater than the inner diameter of the second connecting part, and the outer diameter of the deformable part is less than the inner diameter of the first connecting part and equal to the outer diameter of the second connecting part.

10. The cavity filter according to claim 1, characterized in that: The resonant rod includes a rod body and a disk, the disk and at least a portion of the rod body are located inside the cavity, the rod body is fixedly connected to the cover plate, and the outer diameter of the disk is larger than the outer diameter of the rod body.

11. The cavity filter according to claim 3, characterized in that: The outer diameter of the deformable part is equal to the outer diameter of the first connecting part and smaller than the outer diameter of the second connecting part.

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