Filter and Its Coupling Structure

Abstract

The present invention provides a filter and its coupling structure, which is installed in a cavity. A cover plate is covered on the cavity, and at least two resonant rods are also provided in the cavity. The coupling structure includes a coupling plate, and the coupling plate is fixed on the side of the cover plate close to the cavity and is located between two adjacent resonant rods. In the coupling structure of the present invention, the coupling plate is directly attached and fixed to the inner side of the cover plate. The energy at the top of the resonant rod is the largest. Therefore, setting the coupling plate on the inner side surface of the cover plate is to achieve cross-coupling at the top of the resonant rod. Only a very small coupling area is required to meet a strong coupling amount. Compared with the flying rod structure that uses the side surface of the resonant rod to achieve coupling in the prior art, it does not need to make the coupling disk very large to achieve the same coupling amount. Moreover, the fixed structure is stable by using the attachment and fixing method, the structure is simpler, the requirement for processing accuracy is not high, and the production and processing efficiency is greatly improved and the production cost is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of filtering components, and particularly relates to a filter and its coupling structure. Background Art

[0002] A filter is a device or circuit that processes signals. Its main function is to allow useful signals to pass through with as little attenuation as possible and attenuate useless signals as much as possible. It is often used as a frequency selection device to select communication signal frequencies and filter out clutter or interference signals outside the communication signal frequencies. It is widely used in mobile base stations to reduce intermodulation signal interference and generate high-quality communication signals, and is an indispensable device in electronic communication systems.

[0003] In a cavity filter, a flying bar is commonly used to achieve signal coupling between the resonant bars of two adjacent cavities, and the coupling strength is generally achieved by controlling the size of the flying bar. However, the clamping seat assembly of the traditional flying bar includes a plastic clamping seat and a dumbbell-shaped flying bar. The dumbbell-shaped flying bar is fixed inside the plastic clamping seat, and the plastic clamping seat is clamped in the installation groove inside the cavity. At this time, the fixed connection between the plastic clamping seat and the cavity can only control the fitting tightness through the dimensional tolerance of the parts. If the fitting tolerance difference is too large, it will lead to the control of the fitting tightness by the dimensional tolerance of the parts; if the fitting tolerance difference is too small, it will lead to too large an interference amount, difficult assembly problems, and poor assembly stability, being insecure and unreliable. Therefore, it has high requirements for machining accuracy, resulting in relatively high machining costs. Summary of the Invention

[0004] The purpose of the present invention is to provide a filter and its coupling structure to solve the technical problems in the prior art that the fixing stability of the flying bar is poor, and it has high requirements for machining accuracy, resulting in relatively high machining costs.

[0005] To achieve the above purpose, the technical solution adopted by the present invention is: to provide a coupling structure installed in a cavity. A cover plate is covered on the cavity, and at least two resonant bars are further provided in the cavity. The coupling structure includes a coupling plate, and the coupling plate is fixed on the side of the cover plate close to the cavity, and the coupling plate is located between two adjacent resonant bars.

[0006] Further, the coupling plate is made of an insulating plate, and a first metal layer is provided on one side surface of the insulating plate attached to the cover plate, and a second metal layer is provided on the side surface of the insulating plate away from the cover plate, and the first metal layer and the second metal layer are not connected.

[0007] Further, the coupling plate is fixedly welded to the cover plate.

[0008] Further, a counterbore for accommodating the coupling plate is provided on the side of the cover plate close to the cavity.

[0009] Further, it further includes a first adjusting component located between two adjacent ones of the resonant rods.

[0010] Further, the first adjusting component includes a first coupling member and a first fixing member. The first fixing member is fixed to the side of the cover plate away from the cavity. A first adjusting hole for the first coupling member to pass through is formed in the cover plate, and the first coupling member passes through the first fixing member and is rotatably and fixedly connected to the first fixing member and the cover plate.

[0011] Further, a second adjusting hole for the first coupling member to be inserted into is formed in the coupling plate.

[0012] Further, a thread is formed on the outer edge of the first coupling member, and a thread is also formed on the inner side of the first adjusting hole. The first fixing member is a nut. The first coupling member passes through the first fixing member and is threadedly connected to the first fixing member and the cover plate.

[0013] Further, it includes a cavity, a cover plate covering the cavity, and at least two resonant rods arranged in the cavity. The coupling structure as described above is provided between two adjacent ones of the resonant rods.

[0014] Further, a partition is convexly provided in the cavity. The partition is located between two adjacent ones of the resonant rods, and a notch for accommodating the coupling structure is formed in the partition.

[0015] Further, it further includes a second adjusting component. The second adjusting component faces the resonant rod.

[0016] Further, the second adjusting component includes a second coupling member and a second fixing member. The second fixing member is fixed to the side of the cover plate away from the cavity. A third adjusting hole for the second coupling member to pass through is formed in the cover plate, and the second coupling member passes through the second fixing member and is rotatably and fixedly connected to the second fixing member and the cover plate, and the second coupling member can be inserted into the resonant rod.

[0017] The beneficial effects of the filter and its coupling structure provided by the present invention are as follows: Compared with the prior art, in the coupling structure of the present invention, the coupling plate is directly attached and fixed to the inner side of the cover plate. Since the energy distribution of the resonant rod gradually increases from the bottom to the cover plate area, that is, the energy at the top of the resonant rod is the largest. Therefore, by arranging the coupling plate on the inner side of the cover plate, it is cross-coupled at the top of the resonant rod, and only a very small coupling area is required to meet a strong coupling amount. Compared with the flying rod structure that uses the side of the resonant rod for coupling in the prior art, it is not necessary to make the coupling disk very large to achieve the same coupling amount. The fixed structure is stable by using the attachment and fixation method, the structure is simpler, the requirement for processing accuracy is not high, and the production and processing efficiency is greatly improved and the production cost is reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0019] Figure 1 Schematic three-dimensional structure diagram of the filter provided by the embodiment of the present invention;

[0020] Figure 2 Schematic cross-sectional structure diagram of the filter provided by the embodiment of the present invention;

[0021] Figure 3 Schematic three-dimensional structure diagram of the cavity adopted by the filter provided by the embodiment of the present invention.

[0022] Description of reference numerals:

[0023] 100, cavity; 200, cover plate; 300, resonant rod; 400, coupling structure; 500, second adjustment component; 110, partition; 111, notch; 210, first adjustment hole; 220, third adjustment hole; 410, coupling plate; 420, first adjustment component; 411, second adjustment hole; 421, first coupling member; 422, first fixing member; 510, second coupling member; 520, second fixing member. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0024] The following will clearly and completely describe the technical solutions of the present invention with reference to the drawings. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the protection scope of the present invention.

[0025] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention 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 thus should not be construed as a limitation to the present invention. In addition, the terms "first", "second", "third" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0026] In the description of the present invention, it should be noted that unless otherwise clearly specified and defined, the terms "installed", "connected", "coupled" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0027] In addition, the technical features involved in different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0028] Please refer to Figures 1 to 3 together, and now the filter provided by the present invention will be described. The filter includes a cavity 100, a cover plate 200 covering the cavity 100, and at least two resonant rods 300 disposed in the cavity 100, and a coupling structure 400 is provided between adjacent resonant rods 300. Among them, the cavity 100 refers to a resonant cavity generally commonly used in the prior art. The top end of the cavity 100 has an opening, and the cover plate 200 can cover the opening. A plurality of partition plates 110 are convexly provided inside the cavity 100. Adjacent resonant rods 300 are separated by the partition plates 110. The coupling structure 400 is located above the partition plates 110 and also between two adjacent resonant rods 300. Among them, for the structure of the resonant rod 300, it can directly adopt the resonant rod 300 in the prior art. Its bottom end is directly fixed on the inner surface of the cavity 100, and an empty cup is formed at the top end.

[0029] The coupling structure 400 is installed in the cavity 100. The coupling structure 400 includes a coupling plate 410. The coupling plate 410 is fixed to one side of the cover plate 200 close to the cavity 100, and the coupling plate 410 is located between two adjacent resonance rods 300. The coupling plate 410 is directly attached and fixed to the inner side of the cover plate 200. Since the energy distribution of the resonance rod 300 gradually increases from the bottom to the area of the cover plate 200, that is, the energy at the top of the resonance rod 300 is the largest. Therefore, setting the coupling plate 410 on the inner side surface of the cover plate 200 is to perform cross-coupling at the top of the resonance rod 300. Only a very small coupling area is required to meet a strong coupling amount. Compared with the flying rod structure that uses the side surface of the resonance rod 300 to achieve coupling in the prior art, it does not need to make the coupling disk very large to achieve the same coupling amount. Moreover, the fixed structure is stable with the attachment and fixation method, the structure is simpler, the requirement for processing accuracy is not high, and the production and processing efficiency is greatly improved and the production cost is reduced.

[0030] When adjusting and calculating the coupling amount, it can be adjusted by changing the thickness, length and width dimensions of the coupling plate 410. When adjusting the thickness and dimensions of the plate body, it is easier to process and produce. One side of the cover plate 200 close to the cavity 100 is provided with a sunk groove for accommodating the coupling plate 410. The coupling plate 410 is fixedly embedded inside the sunk groove, and the position of the coupling plate 410 is defined by the inner edge of the sunk groove.

[0031] Among them, the coupling plate 410 can directly use a PCB board. At this time, the existing PCB board is directly used and the corresponding specifications are processed according to requirements, and the cost is lower. It can also use an insulating board (not shown in the figure). A first metal layer (not shown in the figure) is provided on one side surface of the insulating board attached to the cover plate 200, and a second metal layer (not shown in the figure) is provided on the other side surface of the insulating board away from the cover plate 200. The first metal layer and the second metal layer are not connected. The insulating board is generally made of insulating materials such as ceramic chips or plastic sheets. The first metal layer and the second metal layer are respectively located on the opposite side surfaces of the insulating board. The first metal layer is directly fixedly connected to the cover plate 200, and the fixed connection method can be bonding or welding, etc.

[0032] Preferably, the fixation between the coupling plate 410 and the cover plate 200 uses a soldering welding method. When the coupling plate 410 made of a PCB board is used, the soldering has better weather resistance and a wider applicable temperature range. During long-term operation, the temperature range that can be tolerated is -55° to 135°, and the short-term high temperature resistance reaches 260°. If an insulating board made of a ceramic chip is used, the temperature range of high and low temperature resistance is wider, and it can work normally even in the most demanding environment. For the traditional plastic part assembled flying rod structure, its long-term working temperature range is generally -40° to 120°, and the short-term high temperature resistance is only 180°.

[0033] Further, please also refer to Figure 2 , as a specific embodiment of the coupling structure 400 provided by the present invention, it further includes a first adjustment component 420 located between two adjacent resonator rods 300. Specifically, the coupling plate 410 is directly fixedly connected to the cover plate 200. Therefore, for adjusting the magnitude of the coupling amount, the change of the coupling amount can only be achieved by changing the coupling area between the coupling plate 410 and the resonator rod 300, or by changing the distance between the coupling plate 410 and the resonator rod 300. For a filter that has been fixed, it cannot be adjusted anymore. Therefore, a first adjustment component 420 capable of adjusting the coupling amount is provided between the two resonator rods 300.

[0034] Among them, the first adjustment component 420 includes a first coupling member 421 and a first fixing member 422. The first fixing member 422 is fixed on the side of the cover plate 200 away from the cavity 100. A first adjustment hole 210 for the first coupling member 421 to pass through is provided on the cover plate 200, and the first coupling member 421 passes through the first fixing member 422 and is rotationally and fixedly connected to the first fixing member 422 and the cover plate 200. The first coupling member 421 can move up and down in the first adjustment hole 210, so as to change the coupling strength between the two resonator rods 300 by adjusting the depth of the first coupling member 421 inserted into the cavity 100, realizing the adjustability of the cross-coupling strength.

[0035] The first fixing member 422 generally directly uses a nut, and the first coupling member 421 generally directly uses a screw rod. The first fixing member 422 is located on the side of the cover plate 200 away from the cavity 100. The first adjustment hole 210 is provided on the cover plate 200, the second adjustment hole 411 is provided on the coupling plate 410, the first coupling member 421 can pass through the first adjustment hole 210 and the second adjustment hole 411 and be inserted into the interior of the cavity 100, and the first coupling member 421 and the first fixing member 422 are threadedly connected. By rotating the first coupling member 421, the coupling strength between the resonator rods 300 is changed, and the structure is simple, firm and reliable without loosening at all, convenient for production, and low in cost, compared with the traditional coupling structure 400.

[0036] Since the first coupling member 421 needs to be inserted into the interior of the cavity 100, and both the first coupling member 421 and the partition 110 are located between the two resonator rods 300, a notch 111 is reserved on the partition 110 for the first coupling member 421 to move up and down, and the distance between the first coupling member 421 and the partition 110 can also be adjusted as needed, that is, the width and depth of the notch 111 can be adjusted as needed. The width and depth of the notch 111 can adjust the coupling amount, and the distance between the first coupling member 421 and the partition 110 can also adjust the coupling amount.

[0037] For the adjustment of the coupling amount, in addition to adjusting through the first adjustment component 420, it can also be adjusted by the second adjustment component 500. The second adjustment component 500 is directly opposite to the resonant rod 300 to further adjust the coupling strength between the second coupling member 510 and the resonant rod 300.

[0038] Among them, the second adjustment component 500 includes a second coupling member 510 and a second fixing member 520. The second fixing member 520 is fixed on the side of the cover plate 200 away from the cavity 100. A third adjustment hole 220 for the second coupling member 510 to pass through is formed on the cover plate 200. The second coupling member 510 passes through the second fixing member 520 and is rotatably and fixedly connected to the second fixing member 520 and the cover plate 200, and the second coupling member 510 can be inserted into the resonant rod 300. The second coupling member 510 can move up and down in the third adjustment hole 220, so as to change the coupling strength by adjusting the depth of the second coupling member 510 inserted into the cavity 100, and realize the adjustability of the cross-coupling strength.

[0039] Generally, the second fixing member 520 directly uses a nut, and the second coupling member 510 directly uses a screw rod. The second fixing member 520 is located on the side of the cover plate 200 away from the cavity 100. The third adjustment hole 220 is provided on the cover plate 200. The second coupling member 510 can pass through the third adjustment hole 220 and be inserted into the cavity 100. The second coupling member 510 is threadedly connected to the second fixing member 520. By rotating the second coupling member 510, the coupling strength of the resonant rod 300 can be changed. The structure is simple, firm and reliable without loosening at all, convenient for production and low in cost.

[0040] Obviously, the above embodiments are only examples given for clear illustration and not limitations on the implementation manners. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation manners here. The obvious changes or modifications derived therefrom still fall within the protection scope of the present invention.

Claims

1. A coupling structure is installed inside a cavity (100), and a cover plate (200) is covered on the cavity (100). At least two resonant rods (300) are also provided inside the cavity (100). Characterized in that: The coupling structure includes a coupling plate (410). The coupling plate (410) is fixed on the side of the cover plate (200) close to the cavity (100), and the coupling plate (410) is located between two adjacent resonant rods (300). A sunken groove for accommodating the coupling plate (410) is provided on the side of the cover plate (200) close to the cavity (100), and the coupling plate (410) is fixedly welded to the cover plate (200). It further includes a first adjustment component (420) located between two adjacent resonant rods (300). The first adjustment component (420) includes a first coupling member (421) and a first fixing member (422). A second adjustment hole (411) for inserting the first coupling member (421) is formed on the coupling plate (410).

2. The coupling structure according to claim 1, Characterized in that: The coupling plate (410) is made of an insulating plate, and a first metal layer is provided on one side of the insulating plate close to the cover plate (200), and a second metal layer is provided on the side of the insulating plate away from the cover plate (200). The first metal layer and the second metal layer are not connected.

3. The coupling structure according to claim 1, Characterized in that: The first fixing member (422) is fixed on the side of the cover plate (200) away from the cavity (100). A first adjustment hole (210) for the first coupling member (421) to pass through is formed on the cover plate (200), and the first coupling member (421) passes through the first fixing member (422) and the first adjustment hole (210) and is rotatably and fixedly connected to the first fixing member (422) and the cover plate (200).

4. The coupling structure according to claim 3, Characterized in that: Threads are formed on the outer edge of the first coupling member (421), and threads are also formed on the inner side of the first adjustment hole (210). The first fixing member (422) is a nut. The first coupling member (421) passes through the first fixing member (422) and the first adjustment hole (210) and is threadedly connected to the first fixing member (422) and the cover plate (200).

5. A filter, Characterized in that, It includes a cavity (100), a cover plate (200) covered on the cavity (100), and at least two resonant rods (300) provided inside the cavity (100). A coupling structure according to any one of claims 1 to 4 is provided between two adjacent resonant rods (300).

6. The filter according to claim 5, Characterized in that: A partition (110) is further convexly provided inside the cavity (100). The partition (110) is located between two adjacent resonant rods (300), and a notch (111) for accommodating the coupling structure (400) is formed on the partition (110).

7. The filter according to claim 5, characterized in that: it further comprises a second adjusting component (500), and the second adjusting component (500) is opposite to the resonant rod (300).

8. The filter according to claim 7, characterized in that: the second adjusting component (500) comprises a second coupling member (510) and a second fixing member (520), the second fixing member (520) is fixed on a side of the cover plate (200) away from the cavity (100), a third adjusting hole (220) for the second coupling member (510) to pass through is formed in the cover plate (200), and the second coupling member (510) passes through the second fixing member (520) and is rotatably and fixedly connected to the second fixing member (520) and the cover plate (200), and the second coupling member (510) can be inserted into the resonant rod (300).

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