Filter

Abstract

The invention provides a filter. The filter comprises a cavity with an opening in one end, a cover plate installed at the opening end of the cavity and a resonant column installed in the cavity. The outer surface of the cover plate is recessed downwards at a position corresponding to the resonant column to form a mounting groove, and the central position of the mounting groove protrudes upwards to form a cylindrical stud. The filter further comprises a tuning assembly, the tuning assembly comprises a tuning disc and an adjusting screw, the tuning disc is installed in the installation groove, and the side wall of the tuning disc is provided with threads which are in threaded connection with the inner wall of the installation groove. A through hole is formed in the center of the tuning disc, the adjusting screw extends into the through hole to be installed on the stud, the adjusting screw is in threaded connection with the stud, and the adjusting screw can move up and down relative to the stud when rotating so as to adjust the distance between the center of the bottom plate and the tuning disc. And because the cover plate is not provided with a penetrating structure, when the tuning disc or the adjusting screw is rotated, generated metal chips cannot fall into the cavity, so that chipless adjustment is realized, and the intermodulation index is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of communication radio frequency filtering, and in particular to a filter. Background Art

[0002] Currently, the tuning mechanism for RF device filters typically uses a metal screw inserted through a screw hole in a cover plate into the cavity, secured with a nut. Repeated rotation of the metal screw during tuning can easily generate burrs and chips, which can lead to poor performance during power testing, such as sparking or intermodulation.

[0003] With the continuous development of radio frequency communication technology, the frequency band is getting higher and the performance requirements are becoming more stringent. The traditional tuning screw and cover screw hole debugging method can no longer meet the requirements of frequency and intermodulation performance. Therefore, a solution is urgently needed. Summary of the Invention

[0004] The purpose of the present invention is to overcome the above technical problems and provide a filter.

[0005] In order to achieve the above-mentioned purpose, the technical solution provided by the present invention is as follows: it comprises a cavity with an opening at one end, a cover plate installed at the open end of the cavity and a resonant column installed in the cavity; the outer surface of the cover plate is recessed downward at the position corresponding to the resonant column to form a mounting groove, and the inner wall of the mounting groove is provided with a thread; the bottom plate of the mounting groove is elastic and its center position protrudes upward to form a cylindrical stud, and the stud is a blind hole structure with a closed bottom end and an internal thread is processed in the center; the filter also includes a tuning assembly, and the tuning assembly includes a tuning disk and an adjusting screw, the tuning disk is installed in the mounting groove, and the side wall of the tuning disk is provided with a screw thread. The adjusting screw is threadedly connected to the inner wall of the cover plate; the lower end of the tuning disk or the base plate is provided with an outwardly protruding adjustment portion, and the adjustment portion is located at a position deviating from the stud, and changes the degree of deformation of the base plate when the tuning disk rotates relative to the mounting slot; a through hole is provided at the center of the tuning disk to expose the stud, and the adjusting screw extends into the through hole and is installed on the stud, the outer diameter of the brim of the adjusting screw is larger than the aperture of the through hole, and the adjusting screw is threadedly connected to the stud, and when the adjusting screw rotates, it can move up and down relative to the stud to adjust the distance between the center of the base plate and the tuning disk.

[0006] As a preferred technical solution, there are two or more resonant columns, the number of the mounting slots is the same as the number of the resonant columns; and the number of the tuning components is the same as the number of the resonant columns.

[0007] As a preferred technical solution, the base plate is provided with an annular step so that the mounting groove has different depths, and the depth of the mounting groove close to its inner wall is smaller than the depth of the center of the mounting groove; the adjustment portion is located in the area corresponding to the center of the mounting groove.

[0008] As a preferred technical solution, the through hole is a circular hole, the stud is a cylinder with one end open, and the diameter of the through hole is slightly larger than the diameter of the stud.

[0009] As a preferred technical solution, a concave adjustment hole is provided on the upper surface of the tuning disk, and the adjustment hole facilitates the rotation of the tuning disk.

[0010] As a preferred technical solution, the adjustment portion is integrally formed on the tuning disk; the adjustment portion and the adjustment hole are formed by stamping at corresponding positions of the tuning disk.

[0011] As a preferred technical solution, the cover plate is further provided with a through hole at a position deviating from the mounting groove; the filter further includes a coupling assembly, the coupling assembly including an adjusting screw and an adjusting nut, the adjusting screw passes through the through hole and extends into the cavity, the adjusting nut is sleeved onto the adjusting screw and is located on the outside of the cover plate for adjusting the depth of the adjusting screw extending into the cavity.

[0012] As a preferred technical solution, the hole wall of the through hole has an inwardly extending annular flange at a position close to the cavity, so that the hole wall of the through hole forms a shoulder at a position close to the cavity; the coupling assembly also includes a rivet nut and a seal; the adjusting screw passes through the adjusting nut, the rivet nut and the seal in sequence; the seal wraps the outer circumferential surface of the rivet nut and the outer circumferential surface of the tuning screw, and is interference fit to the through hole, and the rivet nut and the seal are supported by the shoulder.

[0013] As a preferred technical solution, the seal is non-conductive as a whole or on the surface; the main body thickness of the tuning disk is 80% to 150% of the maximum depth of the mounting groove.

[0014] As a preferred technical solution, the thickness of the base plate ranges from 0.2 mm to 0.5 mm.

[0015] Compared to existing technologies, the cover plate of this invention has no through-hole structure. When rotating the tuning dial or turning the adjustment screw to adjust the frequency, no metal chips are dropped into the cavity, thus achieving chip-free adjustment and improving intermodulation performance. Frequent screw replacement is also unnecessary during frequency adjustment, significantly improving product quality and debugging efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] To further explain the specific technical content of this case, please first refer to the attached drawings, in which: Figure 1 A schematic cross-sectional view of a tuning device provided in an embodiment of the present invention; Figure 2 A schematic diagram of the disassembled structure of a tuning device provided in an embodiment of the present invention; Figure 3 An exploded diagram of a tuning device provided in an embodiment of the present invention; Figure 4 A schematic diagram of a tuning component provided in an embodiment of the present invention; Figure 5 A schematic diagram of an adjusting screw provided in an embodiment of the present invention; Figure 6 Provides a schematic diagram of a cover plate for an embodiment of the present invention; Figure 7 Schematic diagram of the disassembly of the coupling components provided by an embodiment of the present invention; Figure 8 Schematic diagram of a tuning disk provided in an embodiment of the present invention.

[0017] Explanation of symbols: Cavity 10 Resonance column 20 Cover 30 Tuning assembly 40 Tuning plate 41 Adjusting screw 42 brim 42a free end 42b Mounting groove 43 Annular step 48 Inner wall 43a Bottom plate 43b Stud 44 Through hole 45 Mounting hole 46 Adjustment hole 47 Annular step 48 Adjustment portion 49 Coupling assembly 50 annular flange 55a Adjusting screw 51 Adjusting nut 52 Compression rivet nut 53 Seal 54 Through hole 55 Assembly hole 56 DETAILED DESCRIPTION

[0018] like Figure 1 、 Figure 2 and Figure 3The present invention provides a filter 100 comprising a cavity 10 with an open end, a cover plate 30 mounted on the open end of the cavity 10, and a resonant column 20 mounted within the cavity 10. Specifically, the outer surface of the cover plate 30 is recessed downward at a position corresponding to the resonant column 20 to form a mounting groove 43, and the inner wall 43a of the mounting groove 43 is provided with threads; the bottom plate 43b of the mounting groove 43 is elastic and its center protrudes upward to form a cylindrical stud 44. The stud 44 is a blind hole structure with a closed bottom end and an internal thread machined in the center. Preferably, the thickness of the bottom plate 43b ranges from 0.2 mm to 0.5 mm, and preferably, the thickness of the bottom plate 43b is 0.3 mm.

[0019] Furthermore, the filter 100 further includes a tuning assembly 40 , which includes a tuning disk 41 and an adjusting screw 42 . The tuning disk 41 is mounted to the mounting slot 43 , and a side wall of the tuning disk 41 is provided with threads that are threadedly connected to an inner wall 43 a of the mounting slot 30 .

[0020] Preferably, an outer wall of the free end 42b of the adjusting screw 42 is provided with an external thread.

[0021] The upper surface of the tuning disk 41 is evenly provided with concave adjustment holes 47 . The number of the adjustment holes may be 2-4. The tuning disk 41 can be rotated by inserting a finger or a tool into the adjustment hole 47 .

[0022] Furthermore, the lower end of the tuning disk 41 is provided with a protruding adjustment portion 49, located offset from the stud 44. This portion 49 adjusts the degree of deformation of the base plate 43b when the tuning disk 41 rotates relative to the mounting slot 43. Furthermore, the adjustment portion 49 can also be located on the base plate 43b. The adjustment portion 49 and the adjustment hole 47 are formed by stamping at corresponding locations on the tuning disk 41. During stamping, the corresponding location on the top of the tuning disk 41 is recessed to form the adjustment hole, while the adjustment portion 49 is formed on the underside of the tuning disk 41.

[0023] A through hole 45 is provided at the center of the tuning disk 41 to expose the stud 44. Preferably, the through hole 45 is a circular hole, the stud 44 is a cylinder with one end open, and the diameter of the through hole 45 is slightly larger than the diameter of the stud 44. The adjusting screw 42 extends into the through hole 45 and is installed on the stud 44, and the adjusting screw 42 is threadedly connected to the stud 44. The outer diameter of the brim 42a of the adjusting screw 42 is larger than the aperture of the through hole 45. Specifically, the brim 42a of the adjusting screw 42 abuts against the upper surface of the tuning disk 41. When the adjusting screw 42 rotates clockwise, the stud 44 can be pulled toward the tuning disk 41, thereby adjusting the distance between the center portion of the bottom plate 43b and the tuning disk 41. This type of adjustment is to pull the center portion of the bottom plate 43b upward, and the adjusting portion 49 pushes the bottom plate 43b downward. As Figure 2 and 4As shown, a through-hole 46 is provided at the upper end of the adjusting screw 42. Using a tool to rotate through-hole 46, the adjusting screw 42 can be moved up and down relative to the stud 44 to adjust the distance between the center of the bottom plate 43b and the tuning disk 41, thereby adjusting the frequency. Because the cover plate 30 has no through-hole structure, metal chips generated during adjustment are prevented from entering the cavity 10, thereby achieving chip-free adjustment.

[0024] like Figure 2 、 Figure 3 and Figure 8 As shown, the bottom plate 43b is provided with an annular step 48 to make the mounting groove 43 have different depths. The depth of the mounting groove 43 near its inner wall 43a is less than the depth of the center of the mounting groove 43; the adjustment portion 49 is located in the area corresponding to the center of the mounting groove 43.

[0025] Preferably, there are two or more resonant columns 20 , and the number of mounting slots 43 is the same as the number of resonant columns 20 ; and the number of tuning components 40 is the same as the number of resonant columns 20 .

[0026] like Figure 2 、 Figure 3 、 Figure 5 and Figure 7 As shown, the cover plate 30 is further provided with a through hole 55 at a position deviating from the mounting groove 43; the filter 100 also includes a coupling assembly 50, the coupling assembly 50 includes an adjusting screw 51 and an adjusting nut 52, an upper end of the adjusting screw 51 is provided with an assembly hole 56, the adjusting screw 51 passes through the through hole 55 and extends into the cavity 10, the adjusting nut 52 is sleeved on the adjusting screw 51 and is located on the outside of the cover plate 30 for adjusting the depth of the adjusting screw 51 extending into the cavity 10.

[0027] like Figure 6 As shown, the through-hole 55 has an inwardly extending annular flange 55a near the cavity 10, forming a shoulder near the cavity 10. The coupling assembly 50 also includes a rivet nut 53 and a seal 54. Preferably, the seal 54 is entirely non-conductive or has a non-conductive surface. The thickness of the tuning plate 41 (excluding the thickness of the adjustment portion 49) is 80% to 150% of the maximum depth of the mounting slot 43. The adjusting screw 51 passes through the adjusting nut 52, the rivet nut 53, and the seal 54 in sequence. The seal 54 wraps around the outer circumference of the rivet nut 53 and the outer circumference of the tuning screw 51 and is interference-fitted into the through-hole 55, so that the rivet nut 53 and seal 54 are supported by the shoulder. The assembly hole 56 at the upper end of the adjusting screw 51 is rotated with a tool, so that the free end of the adjusting screw 51 extends into the cavity 10, securing the adjusting screw 51 to the cover plate 30.

[0028] Furthermore, the bottom of the cavity 10 protrudes upward to form a support column, and the resonant column 20 is installed on the top of the support column.

[0029] Correspondingly, the tuning disk 41 is threadedly connected to the cover plate 30. By adjusting the tuning disk 41, the bottom plate 43b is deformed downward. The adjusting disk 41 is limited by the depth of the thread on the inner wall 43a of the mounting groove 43, thereby controlling the downward deformation of the cover plate 30 to achieve the purpose of adjusting the frequency.

[0030] Specifically, the rivet nut 53 is a hollow cylindrical structure with a hexagonal flange. The rivet nut 53 is riveted to the cover plate 30. The adjusting screw 51 moves up and down in the rivet nut 53 for tuning. The rivet nut 53 will not fall off due to movement.

[0031] In this embodiment, since there is no through-hole structure in the cover plate 30, metal chips generated when adjusting the frequency by rotating the tuning dial 41 or turning the adjusting screw 42 do not fall into the cavity 10, thus achieving chip-free adjustment. The screw does not need to be replaced during the frequency adjustment process, which reduces the technical problems such as power sparking, intermodulation failure, and unstable indicators caused by metal chips generated during screw rotation tuning entering the cavity, thereby greatly improving product quality and debugging efficiency.

[0032] The above-described embodiments merely illustrate several implementations of the present invention, and while their descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art would be able to make numerous variations and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be determined by the appended claims.

Claims

1. A filter, characterized in that: The filter comprises a cavity (10) with an opening at one end, a cover plate (30) mounted at the open end of the cavity (10), and a resonant column (20) mounted in the cavity (10); the outer surface of the cover plate (30) is recessed downward at a position corresponding to the resonant column (20) to form a mounting groove (43), and the inner wall (43a) of the mounting groove is provided with a thread; the bottom plate (43b) of the mounting groove is elastic and its center position is upwardly protruded to form a cylindrical stud (44), and the stud (44) is a blind hole structure with a closed bottom end and an internal thread is processed at the center; the filter also comprises a tuning assembly (40), the tuning assembly (40) comprises a tuning disk (41) and an adjusting screw (42), the tuning disk (41) is mounted in the mounting groove (43), and the side wall of the tuning disk (41) is provided with a thread and is threadedly connected to the inner wall (43a) of the cover plate (30) The lower end of the tuning disk (41) or the bottom plate (43b) is provided with an outwardly protruding adjusting portion (49), and the adjusting portion (49) is located at a position deviating from the stud (44), and changes the deformation degree of the bottom plate (43b) when the tuning disk (41) rotates relative to the mounting groove (43); a through hole (45) is provided at the center of the tuning disk (41) to expose the stud (44), and the adjusting screw (42) extends into the through hole (45) and is installed on the stud (44), and the outer diameter of the brim (42a) of the adjusting screw (42) is larger than the aperture of the through hole (45), and the adjusting screw (42) is threadedly connected to the stud (44), and when the adjusting screw (42) rotates, it can move up and down relative to the stud (44) to adjust the distance between the center of the bottom plate (43b) and the tuning disk (41).

2. The filter according to claim 1, wherein There are two or more resonant columns (20), the number of the mounting slots (43) is the same as the number of the resonant columns (20), and the number of the tuning components (40) is the same as the number of the resonant columns (20).

3. The filter according to claim 1, wherein The bottom plate (43b) is provided with an annular step (48) so that the mounting groove (43) has different depths. The depth of the mounting groove (43) close to its inner wall (43a) is smaller than the depth of the central portion of the mounting groove (43); the adjusting portion (49) is located in an area corresponding to the central portion of the mounting groove (43).

4. The filter according to claim 1, wherein The through hole (45) is a circular hole, the stud (44) is a cylinder with one end open, and the diameter of the through hole (45) is slightly larger than the diameter of the stud (44).

5. The filter according to claim 1, wherein A concave adjustment hole (47) is provided on the upper surface of the tuning disk (41), and the adjustment hole (47) facilitates the rotation of the tuning disk (41).

6. The filter according to claim 5, characterized in that The adjusting portion (49) is integrally formed on the tuning disk (41); the adjusting portion (49) and the adjusting hole (47) are formed by stamping at corresponding positions of the tuning disk (41).

7. The filter according to claim 2, characterized in that The cover plate (30) is further provided with a through hole (55) at a position deviating from the mounting groove (43); the filter further comprises a coupling assembly (50), the coupling assembly (50) comprising an adjusting screw (51) and an adjusting nut (52), the adjusting screw (51) passing through the through hole (55) and extending into the cavity (10), the adjusting nut (52) being sleeved onto the adjusting screw (51) and located outside the cover plate (30) for adjusting the depth of the adjusting screw (51) extending into the cavity (10).

8. The tuning device according to claim 7, wherein: The hole wall of the through hole (55) has an inwardly extending annular flange (55a) at a position close to the cavity (10), so that the hole wall of the through hole (55) forms a shoulder at a position close to the cavity (10); the coupling assembly (50) further includes a rivet nut (53) and a seal (54); the adjusting screw (51) passes through the adjusting nut (52), the rivet nut (53) and the seal (54) in sequence; the seal (54) wraps the outer peripheral surface of the rivet nut (53) and the outer peripheral surface of the tuning screw (51), and is interference-fitted to the through hole (55), and the rivet nut (53) and the seal (54) are supported by the shoulder.

9. The filter according to claim 8, characterized in that The sealing member (54) is non-conductive as a whole or on a surface; the main body thickness of the tuning disk (41) is 80% to 150% of the maximum depth of the mounting groove (43).

10. The filter according to claim 1, wherein The thickness of the bottom plate (43b) ranges from 0.2 mm to 0.5 mm.

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