Combined tuning structure and cavity filter

Abstract

The invention discloses a combined tuning structure and a cavity filter. The combined tuning structure comprises a base, an annular elastic piece, a U-shaped sleeve, a screw rod and a nut, an adjusting groove with an opening in the upper end is formed in the base, and an annular clamping table is arranged at the lower end of the base; the annular elastic piece is arranged in the adjusting groove, and the lower end abuts against the annular clamping table. The U-shaped sleeve penetrates through the annular elastic piece and the annular clamping table, the lower end of the U-shaped sleeve is closed, and the upper end of the U-shaped sleeve is provided with a flange edge abutting against the upper end of the annular elastic piece. The screw rod is arranged on the U-shaped sleeve in a penetrating manner; the nut is connected with the base and is in threaded connection with the screw rod; the nut is positioned above the U-shaped sleeve; by means of the structure, metal scraps generated by friction between the screw and the nut can all fall into the U-shaped sleeve, the problem that intermodulation is poor due to contact between metal is solved, and the use requirement is met.

Description

Technical Field

[0001] This invention relates to the field of filters, and in particular to a combined tuning structure and cavity filter. Background Technology

[0002] Cavity filters are a very important type of filter. Compared with other types of filters, they have the advantages of robust structure, stable and reliable performance, small size, moderate Q value, long high-end parasitic passband, and good heat dissipation performance, and can be used for higher power and frequency applications.

[0003] A cavity filter typically consists of a cavity, resonator, cover plate, tuning assembly, and input / output connectors. The tuning assembly includes a tuning screw and a tuning nut. In existing designs, the tuning screw is pre-inserted through the tuning nut, and then the tuning screw is rotated through the threads on the cover plate to extend into the cavity. The tuning screw is repeatedly tightened according to the changes in the vector network analyzer graph until the filter's performance meets the design requirements. Finally, the tuning nut is tightened, and the tuning screw is secured by the friction between the tuning nut and the cover plate. Finally, UV adhesive is applied to prevent loosening. However, this type of cavity filter has the following problems: 1. The tuning screw has poor anti-loosening effect and is prone to loosening and displacement under temperature cycling, vibration and impact. The tuning nut is only used to prevent loosening, which invisibly increases the product quality. Applying UV glue increases the product process and cost. 2. Metal debris generated by the friction between the tuning screw and the tuning nut falls directly into the cavity, resulting in poor intermodulation. Filter intermodulation refers to the phenomenon that when multiple signals pass through a nonlinear passive device, the carriers modulate each other due to material or contact nonlinearity, generating interference frequencies. This phenomenon is particularly dangerous in communication systems and may cause interference in the receiving frequency band or even system failure. Therefore, there is an urgent need for a combined tuning structure and cavity filter to solve the above problems. Summary of the Invention

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention proposes a combined tuning structure and cavity filter.

[0005] One embodiment of the present invention provides a technical solution to solve its technical problem: a combined tuning structure, including a base, an annular elastic element, a U-shaped sleeve, a screw, and a nut; The base has an adjustment groove with an opening at the top, and the base has an annular locking platform at the bottom. The annular elastic element is set in the adjustment groove and its lower end abuts against the annular clamping platform; The U-shaped sleeve is inserted into the annular elastic element and the annular clamping platform. The lower end of the U-shaped sleeve is closed, and the upper end is provided with a flange edge that abuts against the upper end of the annular elastic element. The screw is threaded through the U-shaped sleeve; The nut is connected to the base and threaded onto the screw, with the nut positioned above the U-shaped sleeve.

[0006] In one of the preferred embodiments of the present invention, the annular elastic element is configured as an elastic pad.

[0007] As one of the preferred embodiments of the present invention, the height of the annular elastic member is A1, and a variable receiving space is constructed between the lower end face of the flange and the upper end face of the annular mounting plate, with the maximum height of the receiving space being A2, where A1>A2.

[0008] As one of the preferred embodiments of the present invention, the outer side wall of the annular elastic member is provided with a plurality of protrusions arranged along the height direction at intervals on the circumferential side.

[0009] In one of the preferred embodiments of the present invention, the annular elastic element is configured as a helical spring.

[0010] As one of the preferred embodiments of the present invention, the nut is welded or riveted to the base.

[0011] A cavity filter includes a cavity, a cover plate, a resonator, and a tuning structure. The cavity has an upper opening, the cover plate is placed over the opening of the cavity, the resonator is disposed inside the cavity, the base is disposed on the cover plate, and a screw is arranged opposite to the resonator.

[0012] As one of the preferred embodiments of the present invention, the base is welded or riveted to the cover plate.

[0013] A cavity filter includes a cavity, a cover plate, a resonator, and a tuning structure. The cavity has an upper opening, the cover plate is placed over the opening of the cavity, the resonator is mounted on the cover plate, the base is mounted on the cavity, and a screw is arranged opposite to the resonator.

[0014] As one of the preferred embodiments of the present invention, the base is welded or riveted to the cavity.

[0015] The beneficial effects of this invention are as follows: A combined tuning structure and cavity filter, the combined tuning structure includes a base, an annular elastic element, a U-shaped sleeve, a screw, and a nut; the base is provided with an adjustment groove with an open upper end, and an annular retaining plate is provided at the lower end of the base; the annular elastic element is disposed in the adjustment groove and its lower end abuts against the annular retaining plate; the U-shaped sleeve passes through the annular elastic element and the annular retaining plate, the lower end of the U-shaped sleeve is closed, and the upper end is provided with a flange edge that abuts against the upper end of the annular elastic element; the screw passes through the U-shaped sleeve; the nut is connected to the base and threadedly connected to the screw, and the nut is located above the U-shaped sleeve; the above structure allows all metal debris generated by the friction between the screw and the nut to fall into the U-shaped sleeve, and also solves the problem of poor intermodulation caused by metal-to-metal contact, thus meeting the usage requirements. Attached Figure Description

[0016] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which: Figure 1 This is an exploded view of a cavity filter; Figure 2 This is a first cross-sectional view of a first embodiment of a cavity filter; Figure 3 This is a second cross-sectional view of a first embodiment of a cavity filter; Figure 4 This is a schematic diagram of the structure of the first embodiment of the annular elastic element; Figure 5 This is a cross-sectional view of the first embodiment of the annular elastic element; Figure 6 This is a first cross-sectional view of a second embodiment of a cavity filter; Figure 7 This is a second cross-sectional view of a second embodiment of a cavity filter. Detailed Implementation

[0017] This section will describe in detail specific embodiments of the present invention. Preferred embodiments of the present invention are shown in the accompanying drawings. The purpose of the drawings is to supplement the textual description with graphics, so that people can intuitively and vividly understand each technical feature and overall technical solution of the present invention, but they should not be construed as limiting the scope of protection of the present invention.

[0018] In the description of this invention, "multiple" means two or more; "greater than," "less than," and "exceeding" are understood to exclude the stated number; "above," "below," and "within" are understood to include the stated number. The use of "first" and "second" in the description is merely for distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0019] In the description of this invention, it should be understood that the orientation descriptions, such as up, down, front, back, left, right, etc., are based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0020] In this invention, unless otherwise explicitly defined, the terms "setting," "installing," and "connecting" should be interpreted broadly. For example, they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to a fixed connection, a detachable connection, or an integrally formed connection; they can refer to a mechanical connection; they can refer to the internal connection of two components or the interaction between two components. Those skilled in the art can reasonably determine the specific meaning of the above terms in this invention in conjunction with the specific content of the technical solution.

[0021] Reference Figures 1-7 The present invention provides a combined tuning structure, including a base 10, an annular elastic element 20, a U-shaped sleeve 30, a screw 40, and a nut 50; The base 10 is provided with an adjustment groove 11 with an opening at the top, and the base 10 is provided with an annular locking platform 12 at the bottom. The annular elastic element 20 is disposed in the adjustment groove 11 and its lower end abuts against the annular locking platform 12; The U-shaped sleeve 30 is inserted into the annular elastic member 20 and the annular mounting plate 12. The lower end of the U-shaped sleeve 30 is closed, and the upper end is provided with a flange edge 31 that abuts against the upper end of the annular elastic member 20. The screw 40 is inserted into the U-shaped sleeve 30; Nut 50 is connected to base 10 and threaded onto screw 40, and nut 50 is located above U-shaped sleeve 30.

[0022] In this invention, during assembly, the annular elastic element 20 is first fitted onto the outer ring of the U-shaped sleeve 30, and then both are placed into the adjustment groove 11 on the base 10, so that the lower end of the annular elastic element 20 abuts against the upper end face of the annular locking platform 12 and the U-shaped sleeve 30 passes through the inner ring of the annular locking platform 12 and extends to the outside of the base 10. With the base 10 fixed, the nut 50 is placed into the adjustment groove 11 of the base 10 and abuts against the upper end face of the flange edge 31. Then, the nut 50 is welded or riveted onto the base 10. It should be noted that the nut 50 needs to press down on the U-shaped sleeve 30 and the annular elastic element 20 a certain distance so that the annular elastic element 20 is in a compressed state. At this time, the nut 50 is welded or riveted onto the base 10, that is, the U-shaped sleeve 30 and the nut 50 always remain in a tight fit. Finally, the screw 40 is threaded onto the nut 50 and inserted into the U-shaped sleeve 30.

[0023] Reference Figures 1-5In some embodiments, the present invention provides a cavity filter, including a cavity 60, a cover plate 70, a resonator 80, and the aforementioned tuning structure. The cavity 60 has an upper opening, the cover plate 70 covers the opening of the cavity 60, the resonator 80 is disposed inside the cavity 60, the base 10 is disposed on the cover plate 70, and the screw 40 is arranged opposite to the resonator 80. Specifically, the resonator 80 is first installed inside the cavity 60, and the tuning structure is assembled according to the above process. Then, the base 10 is installed on the cover plate 70 by welding or riveting, so that the U-shaped sleeve 30 and the screw 40 are arranged opposite to the resonator 80. The resonator 80 is connected to a vector network analysis via an input / output connector. After the instrument is installed, the U-shaped sleeve 30 is pushed to compress the annular elastic element 20 by rotating the screw 40 in the forward direction, and it also moves towards the resonator 80. Alternatively, the screw 40 is rotated in the reverse direction, causing the screw 40 to move away from the resonator 80. Under the elastic potential energy of the annular elastic element 20, the U-shaped sleeve 30 moves synchronously away from the resonator 80. The screw 40 is rotated repeatedly until the performance of the filter meets the design requirements. During the forward or reverse rotation of the screw 40, the annular elastic element 20 can maintain the tightness between the screw 40 and the nut 50 through the U-shaped sleeve 30, that is, maintain the relative position between the screw 40 and the nut 50, and prevent the screw 40 from loosening without applying glue.

[0024] Reference Figures 1-5 In some embodiments, the present invention also provides a cavity filter, including a cavity 60, a cover plate 70, a resonator 80, and the aforementioned tuning structure. The cavity 60 has an upper opening, the cover plate 70 covers the opening of the cavity 60, the resonator 80 is disposed on the cover plate 70, the base 10 is disposed on the cavity 60, and the screw 40 is arranged opposite to the resonator 80. Specifically, the resonator 80 is first installed inside the cover plate 70, and the tuning structure is assembled according to the above process. Then, the base 10 is installed on the cavity 60 by welding or riveting, with the U-shaped sleeve 30 and the screw 40 arranged opposite to the resonator 80. The resonator 80 is connected to a vector network via an input / output connector. After the filter is rotated, the U-shaped sleeve 30 is pushed to compress the annular elastic element 20 by rotating the screw 40 in the forward direction, and it also moves towards the resonator 80. Alternatively, the screw 40 is rotated in the reverse direction, causing the screw 40 to move away from the resonator 80. Under the elastic potential energy of the annular elastic element 20, the U-shaped sleeve 30 moves synchronously away from the resonator 80. The screw 40 is rotated repeatedly until the performance of the filter meets the design requirements. During the forward or reverse rotation of the screw 40, the annular elastic element 20 can maintain the tightness between the screw 40 and the nut 50 through the U-shaped sleeve 30, that is, maintain the relative position between the screw 40 and the nut 50, and prevent the screw 40 from loosening without applying glue.

[0025] Reference Figures 1-5In some embodiments, the annular elastic element 20 is configured as an elastic pad 20a with a height of A1. A variable accommodating space is constructed between the lower end face of the flange edge 31 and the upper end face of the annular mounting platform 12, with a maximum height of A2, where A1 > A2. Specifically, when the screw 40 is rotated, the elastic pad 20a can be elastically deformed by being squeezed by the U-shaped sleeve 30. Since the nut 50 and the base 10 are fixedly connected, a variable accommodating space is constructed between the lower end face of the flange edge 31 and the upper end face of the annular mounting platform 12. The elastic pad 20a deforms in this accommodating space. By making A1 > A2, the elastic pad 20a can be used to keep the screw 40 and the nut 50 constantly pressed together by the U-shaped sleeve 30.

[0026] Reference Figures 1-5 In some embodiments, the thickness of the elastic pad 20a is B1, and the distance between the outer wall of the U-shaped sleeve 30 and the inner wall of the base 10 is B2, where B1>B2. This arrangement allows the elastic pad 20a to maintain a tight contact with the inner wall of the base 10 and with the outer wall of the U-shaped sleeve 30, further reducing the risk of metal debris generated by the friction between the screw 40 and the nut 50 falling into the cavity 60.

[0027] Reference Figures 1-5 In a further embodiment, the elastic pad 20a is made of silicone rubber, which is a polymer material whose main chain is composed of alternating silicon and oxygen atoms. It has the characteristics of being odorless and non-toxic, resistant to high and low temperatures, and physiologically inert. It can work for a long time at 180°C, withstand high temperatures above 300°C for a short period of time, and still maintain its elasticity for several weeks at 200°C. Ordinary silicone rubber is resistant to low temperatures of -55°C. The function of the annular elastic element 20 is to maintain the continuous upward preload of the U-shaped sleeve 30.

[0028] Reference Figures 1-5 In some embodiments, the outer side wall of the elastic pad 20a is provided with a plurality of protrusions 21 arranged along the height direction at intervals in the circumferential direction, which can improve the compression ratio of the elastic pad 20a. The number and shape of the protrusions 21 are not limited, and the shape can be triangular, inferior circular, superior circular, trapezoidal, etc.

[0029] Reference Figure 1 , Figures 6-7 In some embodiments, the annular elastic element 20 is configured as a helical spring 20b.

[0030] The advantages of this invention are: the above structure allows all the metal debris generated by the friction between the screw and the nut to fall into the U-shaped sleeve, and also solves the problem of poor intercontact caused by the contact between metals, thus meeting the usage requirements.

[0031] Of course, the present invention is not limited to the above-described embodiments. Those skilled in the art can make equivalent modifications or substitutions without departing from the spirit of the present invention. All such equivalent modifications and substitutions are included within the scope defined by the claims of this application.

Claims

1. A combined tuning structure, characterized in that: It includes a base (10), an annular elastic element (20), a U-shaped sleeve (30), a screw (40), and a nut (50); The base (10) is provided with an adjustment groove (11) with an upper opening, and the lower end of the base (10) is provided with an annular mounting plate (12). The annular elastic element (20) is disposed in the adjustment groove (11) and its lower end abuts against the annular locking platform (12); The U-shaped sleeve (30) is inserted into the annular elastic member (20) and the annular mounting plate (12). The lower end of the U-shaped sleeve (30) is closed, and the upper end is provided with a flange edge (31) that abuts against the upper end of the annular elastic member (20). The screw (40) passes through the U-shaped sleeve (30); The nut (50) is connected to the base (10) and threaded onto the screw (40), and the nut (50) is located above the U-shaped sleeve (30).

2. The combined tuning structure according to claim 1, characterized in that: The annular elastic element (20) is configured as an elastic pad (20a).

3. The combined tuning structure according to claim 2, characterized in that: The height of the elastic pad (20a) is A1, and a variable receiving space is formed between the lower end face of the flange edge (31) and the upper end face of the annular mounting plate (12), with the maximum height of the receiving space being A2, where A1>A2.

4. The combined tuning structure according to claim 2, characterized in that: The outer side wall of the elastic pad (20a) is provided with a plurality of raised strips (21) arranged along the height direction at intervals in the circumferential direction.

5. The combined tuning structure according to claim 1, characterized in that: The annular elastic element (20) is configured as a helical spring (20b).

6. The combined tuning structure according to claim 1, characterized in that: The nut (50) is welded or riveted to the base (10).

7. A cavity filter, characterized in that: The device includes a cavity (60), a cover plate (70), a resonator (80), and a tuning structure as described in any one of claims 1-6. The cavity (60) has an upper opening, the cover plate (70) covers the opening of the cavity (60), the resonator (80) is disposed inside the cavity (60), the base (10) is disposed on the cover plate (70), and the screw (40) is arranged opposite to the resonator (80).

8. The combined tuning structure according to claim 7, characterized in that: The base (10) is welded or riveted to the cover plate (70).

9. A cavity filter, characterized in that: The device includes a cavity (60), a cover plate (70), a resonator (80), and a tuning structure as described in any one of claims 1-6. The cavity (60) has an upper opening, the cover plate (70) covers the opening of the cavity (60), the resonator (80) is disposed on the cover plate (70), the base (10) is disposed on the cavity (60), and the screw (40) is arranged opposite to the resonator (80).

10. A combined tuning structure according to claim 9, characterized in that: The base (10) is welded or riveted to the cavity (60).

Images