Cavity filter
By integrally forming the capacitive coupling plate on the resonator and using adjustable adjustment screws, the problem of too small numerical adjustment range of the capacitive coupling is solved, and a cavity filter with a larger adjustment range and higher performance is achieved.
Patent Information
- Application Number
- CN202422344965.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-25
- Publication Date
- 2025-07-04
- Estimated Expiration
- 2034-09-25
AI Technical Summary
The capacitive coupling numerical adjustment range in existing filters is too small, resulting in reduced performance.
The capacitive coupling piece is integrally formed on the resonator and the adjustable setting in the cavity through adjustment screws, eliminating the fixation of polytetrafluoroethylene or engineering plastic with a dielectric constant greater than 2, simplifying the internal structure.
The capacitive coupling numerical adjustment range is increased, production assembly and debugging are simplified, and filter performance is improved.
Smart Images
Figure CN223066435U_ABST
Abstract
Description
Technical Field
[0001] This application belongs to the field of communication technologies, and more particularly, relates to a cavity filter. Background Art
[0002] In existing filters, there is generally a capacitive coupling device, which is used to form filter capacitive transmission zeros / poles, so that the filter can obtain a narrower transition bandwidth and very small stopband ripple. The capacitive coupling device in the existing filter generally includes a resonator, a flybar, a support base for clamping the flybar, and a capacitive coupling adjustment screw. The capacitive coupling adjustment screw extends into the support base, and the magnitude of the capacitive coupling is adjusted by adjusting the distance between the capacitive coupling adjustment screw and the flybar.
[0003] Generally speaking, the support base is machined from polytetrafluoroethylene or other engineering plastics with a dielectric constant greater than 2 and assembled in the side wall of the filter cavity. As a result, the support base isolates 80% of the capacitance formed by the capacitive coupling adjustment screw and the flybar, resulting in a numerical adjustment range of only 20% for the capacitive coupling device, thereby reducing the performance of the filter. Summary of the Utility Model
[0004] The purpose of the embodiments of this application is to provide a cavity filter to solve the technical problem of too small a numerical adjustment range of capacitive coupling in the prior art.
[0005] To achieve the above purpose, the technical solution adopted in the embodiments of this application is to provide a cavity filter, which includes:
[0006] A cavity and a cover plate welded to cover the opening of the cavity;
[0007] Installation posts are provided at the bottom of the cavity, and a plurality of resonators are fixedly arranged in the installation posts. Among some adjacent two of the resonators, at least one of the resonators is integrally formed with a capacitive coupling sheet, the capacitive coupling sheet extends towards the other resonator, and in the orthographic projection plane, the capacitive coupling sheet is located on the connection line between the axes of the adjacent two resonators;
[0008] An adjustment screw is rotatably arranged on the cover plate, and its screw rod extends into the cavity and the depth in the cavity can be adjusted. In the orthographic projection plane, the adjustment screw is located on one side of the midpoint of the connection line between the axes of the adjacent two resonators.
[0009] Optionally, when only one of the resonators is formed with the capacitive coupling sheet, the length of the capacitive coupling sheet is greater than half of the minimum distance between the adjacent two resonators.
[0010] Optionally, when the capacitance coupling plates are formed on two adjacent resonators, the two adjacent resonators are symmetrically arranged, and the length of each capacitance coupling plate is less than half of the minimum distance between the two adjacent resonators.
[0011] Optionally, the shortest distance between the adjusting screw and the capacitance coupling plate is equal to the distance between the ends of the two capacitance coupling plates.
[0012] Optionally, the resonator is in the shape of a tubular column with a wall thickness, and the resonator includes a funnel-shaped top and a tubular middle part. An installation hole for passing through a bolt is formed inside the resonator; the bolt passes through the installation hole to fix the resonator to the installation column, the side wall of the head of the bolt abuts against the inclined inner wall of the resonator, and the rod part of the bolt abuts against the inner wall of the middle part of the resonator.
[0013] Optionally, a flanging structure is formed around the opening edge of the funnel shape at the top of the resonator.
[0014] Optionally, the capacitance coupling plate is formed on the flanging structure of the resonator.
[0015] Optionally, the capacitance coupling plate includes a horizontal section and a folding section at the end of the horizontal section, and the folding section extends and bends in the depth direction of the cavity.
[0016] Optionally, the resonator is formed by stamping a plate-shaped metal.
[0017] The cavity filter provided by the embodiment of the present application has at least the following beneficial effects:
[0018] By integrally forming the capacitance coupling plate on the resonator and arranging the adjusting screw on one side of the capacitance coupling plate, on the one hand, the assembly and connection of the capacitance coupling plate in the cavity do not require the use of polytetrafluoroethylene or other engineering plastics with a dielectric constant greater than 2, thus avoiding the problem that the capacitance adjustment value range is affected. On the other hand, the capacitance coupling plate and the resonator are integrally formed, which can reduce the number of components inside the cavity filter, simplify the structure, and facilitate production, assembly and debugging. Description of the Drawings
[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.
[0020] Figure 1 and Figure 2Cross-sectional views of cavity filters in different embodiments of the present application;
[0021] Figure 3 Assembly schematic diagrams of two adjacent resonators in some embodiments of the present application;
[0022] Figure 4 Top views of cavity filters in some embodiments of the present application;
[0023] Figure 5 Assembly schematic diagrams of two adjacent resonators in other embodiments of the present application;
[0024] Figure 6 Top views of cavity filters in other embodiments of the present application. Detailed implementation manners
[0025] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present application clearer, the present application will be further described in detail below with reference to the accompanying drawings and embodiments.
[0026] It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.
[0027] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element.
[0028] When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.
[0029] It should be understood that the orientation or positional relationship indicated by the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation to the present application.
[0030] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features.
[0031] In the description of the present application, "a plurality" means two or more unless otherwise specifically defined.
[0032] Please refer to togetherFigures 1 to 6 , the cavity filter provided by the embodiments of the present application will be described now.
[0033] Referring to Figure 1 and Figure 2 , it can be understood that the cavity filter described in the present application includes a cavity 100 and a cover plate 200 welded to cover the opening of the cavity 100. Among them, the cavity 100 can be formed by die-casting process or by 3D printing process, and the specific is not limited thereto.
[0034] Mounting posts 300 are integrally formed at the bottom of the cavity 100, and a resonator 400 is fixedly arranged on each mounting post 300. Among them, in the resonance combination formed by some adjacent two resonators 400, at least one resonator 400 is integrally formed with a capacitive coupling piece 500, and the capacitive coupling piece 500 extends towards the other resonator 400. That is, in the orthographic projection plane, the projection of the capacitive coupling piece 500 coincides with the projection of the line connecting the axes of the adjacent two resonators 400.
[0035] It can be understood that in a resonance combination, it can be that only one resonator 400 is formed with a capacitive coupling piece 500. At this time, the capacitive coupling piece 500 extends towards the other resonator 400; it can also be that both of the two resonators 400 are formed with capacitive coupling pieces 500. At this time, the two capacitive coupling pieces 500 extend towards each other and there is a distance between their respective ends.
[0036] An adjusting screw 600 is rotatably arranged on the cover plate 200. The adjusting screw 600 is rotatably arranged on the cover plate 200 and its screw rod extends into the cavity 100 and the depth in the cavity 100 can be adjusted. At the same time, in the orthographic projection plane, the adjusting screw 600 is located on one side of the midpoint of the line connecting the axes of the adjacent two resonators 400. That is, the screw rod of the adjusting screw 600 is located on one side of the capacitive coupling piece 500.
[0037] By arranging the capacitive coupling sheet 500, the resonator 400, and the adjusting screw 600 in such a way, on the one hand, the capacitive coupling sheet 500 is integrally formed on the resonator 400, and there is no need to set polytetrafluoroethylene or other engineering plastics with a dielectric constant greater than 2 on the cavity 100 to fix the capacitive coupling sheet 500, thus avoiding the problem that the capacitance adjustment value range is affected and effectively increasing the capacitance coupling value adjustment of the cavity filter; on the other hand, the capacitive coupling sheet 500 is integrally formed on the resonator 400, and the capacitive coupling sheet 500 does not need an additional connection structure to be fixed inside the cavity 100, thus simplifying the number of components inside the cavity 100 and facilitating the production, assembly, and debugging of the cavity filter; on the other hand, the adjusting screw 600 is arranged on one side of the capacitive coupling sheet 500, so that the adjustable range of the length extending into the cavity 100 is larger, that is, the capacitance coupling value adjustment range of the cavity filter is larger, thus effectively improving the performance of the cavity filter.
[0038] Reference Figure 3 and Figure 4 , in some embodiments, when the capacitive coupling sheet 500 is formed only on one of the resonators 400, the length of the capacitive coupling sheet 500 is greater than half of the minimum spacing distance between two adjacent resonators 400. That is, the end of the capacitive coupling sheet 500 is located on one side of the midpoint of the line connecting the respective axes of two adjacent resonators 400.
[0039] Reference Figure 5 and Figure 6 , in some other embodiments, when the capacitive coupling sheets 500 are formed on both of two adjacent resonators 400, the two adjacent resonators 400 are symmetrically arranged, and the length of each capacitive coupling sheet 500 is less than half of the minimum spacing distance between two adjacent resonators 400. That is, the end spacing distances of the two capacitive coupling sheets 500 are set.
[0040] It can be understood that in practical applications, in different resonance combinations in the same cavity filter, in some resonance combinations, only one resonator 400 has the capacitive coupling sheet 500 formed on it, and in some other resonance combinations, the capacitive coupling sheets 500 are formed on both of the two resonators 400. The position arrangement modes of different resonance combinations with different numbers of capacitive coupling sheets 500 can be set according to actual requirements.
[0041] Reference Figure 5 and Figure 6, Further, in the embodiment where the capacitance coupling sheets 500 are formed on the adjacent two resonators 400, the shortest distance between the adjusting screw 600 and each capacitance coupling sheet 500 is equal to the distance between the ends of the two capacitance coupling sheets 500. Specifically, in some embodiments, the distance between the ends of the two capacitance coupling sheets 500 is 1 mm, and at the same time, the distance between the adjusting screw 600 and each capacitance coupling sheet 500 is also 1 mm.
[0042] Reference Figure 3 and Figure 5 , In some embodiments, the resonator 400 is in the shape of a tubular column with a wall thickness. The resonator 400 includes a funnel-shaped top and a tubular middle part. An installation hole 410 for passing through a bolt is formed inside the resonator 400; the bolt passes through the installation hole 410 to fix the resonator 400 to the installation column 300. The side wall of the head of the bolt abuts against the inclined inner wall of the resonator 400, and the rod part of the bolt abuts against the inner wall of the middle part of the resonator 400. By setting the resonator 400 in this way, when the bolt fixes the resonator 400 to the installation column 300, the contact area between the bolt and the inner wall of the resonator 400 is larger, so as to enhance the connection stability of the resonator 400 on the installation column 300.
[0043] Further, reference Figure 3 and Figure 5 , A flanging structure 420 is formed around the opening edge of the funnel-shaped top of the resonator 400, and the aforementioned capacitance coupling sheet 500 is formed on the flanging structure 420 of the resonator 400.
[0044] Further, reference Figure 3 and Figure 5 , The capacitance coupling sheet 500 includes a horizontal section 510 and a folding section 520 located at the end of the horizontal section 510. The folding section 520 is in the shape of a straight section and extends and bends in the depth direction of the cavity 100.
[0045] Based on the above embodiments, the resonator 400 is formed by stamping a plate-shaped metal.
[0046] The above are only the preferred embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present application shall be included in the protection scope of the present application.
Claims
1. A cavity filter, characterized in that, Comprising: A cavity and a cover plate welded to the opening of the cavity; Mounting posts are provided at the bottom of the cavity, and a plurality of resonators are fixedly arranged in the mounting posts. Among some adjacent two resonators, at least one of the resonators is integrally formed with a capacitive coupling piece, the capacitive coupling piece extends towards the other resonator, and in the orthographic projection plane, the capacitive coupling piece is located on the connection line between the axes of the adjacent two resonators; An adjusting screw is rotatably arranged on the cover plate, and its screw rod extends into the cavity and the depth in the cavity can be adjusted. In the orthographic projection plane, the adjusting screw is located on one side of the midpoint of the connection line between the axes of the adjacent two resonators.
2. The cavity filter according to claim 1, wherein: When only one of the resonators is formed with the capacitive coupling piece, the length of the capacitive coupling piece is greater than half of the minimum distance between the adjacent two resonators.
3. The cavity filter according to claim 1, wherein: When both of the adjacent two resonators are formed with the capacitive coupling pieces, the adjacent two resonators are symmetrically arranged, and the length of each capacitive coupling piece is less than half of the minimum distance between the adjacent two resonators.
4. The cavity filter according to claim 3, wherein: The shortest distance between the adjusting screw and the capacitive coupling piece is equal to the distance between the ends of the two capacitive coupling pieces.
5. The cavity filter according to any one of claims 1 to 4, characterized in that: The resonator is in the shape of a tubular column with a wall thickness, and the resonator includes a funnel-shaped top and a tubular middle part. An installation hole for passing through a bolt is formed inside the resonator; the bolt passes through the installation hole to fix the resonator to the mounting post, the side wall of the head of the bolt abuts against the inclined inner wall of the resonator, and the rod part of the bolt abuts against the inner wall of the middle part of the resonator.
6. The cavity filter according to claim 5, characterized in that: A flanging structure is formed around the opening edge of the funnel shape at the top of the resonator.
7. The cavity filter according to claim 6, characterized in that: The capacitive coupling piece is formed on the flanging structure of the resonator.
8. The cavity filter according to claim 7, wherein: The capacitive coupling piece includes a horizontal section and a folded section at the end of the horizontal section, and the folded section extends and bends in the depth direction of the cavity.
9. The cavity filter according to claim 7, wherein: The resonator is formed by stamping a plate-shaped metal.