Closed loop type ANT tap structure

Abstract

The invention discloses a closed loop type ANT tap structure, and belongs to the field of filters. A closed loop type ANT tap structure comprises a cavity and further comprises an input connector and an output connector which are arranged on the two sides of the cavity respectively, and one end, arranged in the cavity, of the input connector and one end, arranged in the cavity, of the output connector are connected with an input core rod and an output core rod respectively; the two first supporting parts are fixedly connected to the inner side wall of the cavity; the cover plate is arranged on the cavity, and a port coupling tuning screw is arranged on the cover plate; a conventional tap coupling copper sheet is changed into a closed loop type copper sheet, and coupling is enhanced or weakened by using the port coupling tuning screws, so that the product index consistency is relatively high, the problem of inconsistent tap coupling in the actual application process is solved, the design is simple, the consistency is high, and the cost is low. The design improves the consistency, stability, reliability and operability of products, and has the characteristics of low cost and convenience in debugging.

Description

Technical Field

[0001] This invention relates to the field of filter technology, and in particular to a closed-loop ANT tap structure. Background Technology

[0002] In the field of filters, the closed-loop ANT tap structure can help the filter more accurately connect to the frequency band of the antenna for receiving or transmitting. By adjusting the position of the tap in the closed loop, the resonant frequency of the antenna can be changed, so that the antenna and the filter work together to accurately select the target frequency band signal and suppress interference from other frequency bands.

[0003] In the design and debugging of communication filters, taps with different coupling values ​​are used. Different coupling values ​​are required depending on the bandwidth. However, in the actual assembly and debugging process, the difference in tap coupling values ​​caused by processing errors and assembly errors often affects the consistency of product indicators. That is, some product indicators are preferred, while some indicators are deviated, resulting in relatively poor consistency. In view of this, this invention is proposed. Summary of the Invention

[0004] The purpose of this invention is to solve the problems existing in the prior art by proposing a closed-loop ANT tap structure.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: A closed-loop ANT tap structure includes a cavity and further includes: The input connector and output connector are respectively located on both sides of the cavity, and the input connector and output connector are respectively connected to the input core rod and output core rod at one end inside the cavity; Both first support parts are fixedly connected to the inner sidewall of the cavity; Two second support parts are fixedly installed inside the bottom of the cavity, and a limiting part is provided between the two first support parts and the two second support parts; Both the input copper sheet and the output copper sheet are disposed within the cavity, and the input copper sheet and the output copper sheet are respectively engaged with the input core rod and the output core rod; A cover plate is provided on the cavity, and the cover plate is provided with a port coupling tuning screw.

[0006] Preferably, the input copper sheet is disposed on the first support portion and the second support portion near the input core rod end, and the output copper sheet is disposed on the first support portion and the second support portion near the output core rod end, with the limiting portions located on both sides of the cavity respectively inserted into the input copper sheet and the output copper sheet.

[0007] Preferably, both the first support portion and the second support portion are provided with mounting holes, and both the first support portion and the second support portion are provided with annular support members corresponding to the mounting holes, and the input copper sheet and the output copper sheet are placed on the annular support members.

[0008] Furthermore, both the input copper sheet and the output copper sheet are provided with through holes corresponding to the mounting hole positions, and both the input copper sheet and the output copper sheet are connected with copper sheet fixing screws. The copper sheet fixing screws pass through the through holes and the annular support in sequence and are connected in the mounting hole.

[0009] Furthermore, both the input copper sheet and the output copper sheet are provided with welding grooves. One end of the input core rod placed inside the cavity is connected to the welding groove on the input copper sheet, and the other end of the output core rod placed inside the cavity is connected to the welding groove on the output copper sheet.

[0010] Preferably, an input fixing plate and an output fixing plate are respectively connected to the outer walls of both sides of the cavity. The input connector is fixedly connected to the input fixing plate, and the output connector is fixedly connected to the output fixing plate. The input fixing plate is provided with an input fixing screw, and the output fixing plate is provided with an output fixing screw. The input fixing plate and the output fixing plate are respectively connected to the outer walls of both sides of the cavity by the input fixing screw and the output fixing screw.

[0011] Preferably, both the cavity and the limiting part are provided with connecting holes, a locking screw is connected to the cover plate, the bottom of the locking screw passes through the cover plate and is connected in the connecting hole, and both the input copper plate and the output copper plate are provided with recessed holes, and the limiting part is inserted into the recessed holes.

[0012] Preferably, there are multiple port coupling tuning screws, and one end of each of the multiple port coupling tuning screws is positioned above the input copper plate and the output copper plate inside the cavity. Each of the multiple port coupling tuning screws is provided with a port coupling tuning nut, and the port coupling tuning nut abuts against the top outer wall of the cover plate.

[0013] Furthermore, the cover plate is also provided with a plurality of frequency tuning screws and auxiliary tuning screws, which are arranged in an alternating manner. A frequency tuning nut and an auxiliary tuning nut are respectively connected to the frequency tuning screws and auxiliary tuning screws, and the frequency tuning nut and the auxiliary tuning nut abut against the top outer wall of the cover plate.

[0014] Furthermore, the cavity is provided with a resonant post, the resonant post is provided with a resonant hole, one end of the frequency tuning screw is placed in the cavity and connected to the resonant hole, and the auxiliary tuning screw extends into the cavity to a greater depth than the frequency tuning screw extends into the cavity.

[0015] Compared with the prior art, the present invention provides a closed-loop ANT tap structure, which has the following advantages: 1. This closed-loop ANT tap structure, by slightly altering the relative position between the port coupling tuning screw and the input copper plate, can make the filter's passband flatter and enhance its ability to suppress high-frequency signals in specific frequency bands. Multiple port coupling tuning screws are located above both the input and output copper plates. Screws closer to the input and output copper plates deepen and enhance coupling, while those slightly further away, closer to the middle of the cavity, weaken or deepen coupling. This closed-loop design enables tap coupling and allows for free adjustment of tap strength. By replacing the conventional tapped coupling copper plates with a closed-loop input and output copper plate structure and using port coupling tuning screws at corresponding positions on the cover plate to enhance or weaken coupling, the product's performance consistency is relatively high.

[0016] 2. The closed-loop ANT tap structure uses PEI material for the annular support and PEEK material for the copper plate fixing screws. The non-metallic materials have good electrical insulation properties and will not introduce additional electromagnetic interference or change the electromagnetic environment of the input and output copper plates during use. In filters, which are sensitive to the electromagnetic environment and require precise control of signal transmission and filtering effect, the non-metallic components will not interfere with the electrical path, which helps to maintain a stable signal transmission state and ensure the normal realization of the filtering function.

[0017] The parts of this device not covered are the same as or can be implemented using existing technologies. This invention replaces the conventional tap coupling copper sheet with a closed-loop copper sheet and uses port coupling tuning screws at corresponding positions on the cover plate to enhance or weaken the coupling, thereby achieving relatively high product consistency. It solves the problem of inconsistent tap coupling in practical applications. Moreover, the design is simple and highly consistent. This design improves the consistency, stability, reliability, and operability of the product, and features low cost and convenient debugging. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of a closed-loop ANT tap structure proposed in this invention; Figure 2 This is a schematic diagram of a closed-loop ANT tap structure without a cover plate proposed in this invention; Figure 3 This is a schematic diagram of the internal structure of the cavity in a closed-loop ANT tap structure proposed in this invention; Figure 4 This is a cross-sectional view of a closed-loop ANT tap structure proposed in this invention. Figure 1 ; Figure 5 This is a cross-sectional view of a closed-loop ANT tap structure proposed in this invention. Figure 2 ; Figure 6 This is a schematic diagram of the output copper sheet in a closed-loop ANT tap structure proposed in this invention; Figure 7 This invention proposes a closed-loop ANT tap structure. Figure 2 Enlarged view of section A; Figure 8 This invention proposes a closed-loop ANT tap structure. Figure 2 Enlarged view of section B.

[0019] In the diagram: 1. Cavity; 101. Connecting hole; 102. First support part; 103. Second support part; 104. Limiting part; 105. Mounting hole; 106. Resonant column; 107. Resonant hole; 2. Cover plate; 201. Locking screw; 202. Frequency tuning screw; 203. Frequency tuning nut; 204. Auxiliary tuning screw; 205. Auxiliary tuning nut; 206. Port coupling tuning screw; 207. Port coupling tuning nut; 3. Input fixing plate; 301. Input connector; 302. Input fixing screw; 303. Input core rod; 4. Output fixing plate; 401. Output connector; 402. Output fixing screw; 403. Output core rod; 5. Input copper sheet; 501. Welding groove; 502. Through hole; 503. Concave hole; 504. Annular support; 505. Copper sheet fixing screw; 6. Output copper sheet. Detailed Implementation

[0020] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0021] In the description of this invention, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship 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 limitations on this invention.

[0022] Example 1: Refer to Figures 1-8A closed-loop ANT tap structure includes a cavity 1, and an input connector 301 and an output connector 401 respectively disposed on both sides of the cavity 1. The ends of the input connector 301 and the output connector 401 disposed inside the cavity 1 are respectively connected to an input core rod 303 and an output core rod 403. Two first support parts 102 are fixedly connected to the inner side wall of the cavity 1, and two second support parts 103 are fixedly disposed inside the bottom of the cavity 1. A limiting part 104 is provided between the two first support parts 102 and the two second support parts 103. An input copper plate 5 and an output copper plate 6 are both disposed inside the cavity 1, and the input copper plate 5 and the output copper plate 6 respectively cooperate with the input core rod 303 and the output core rod 403. A cover plate 2 is disposed on the cavity 1, and a port coupling tuning screw 206 is provided on the cover plate 2.

[0023] In this embodiment, during use, a signal can be input through the input connector 301. The input signal is then transmitted to the input copper plate 5 through the input core rod 303. The input copper plate 5 is a key component for the electrical connection between the filter and the external signal source. Its main function is to stably and reliably introduce the electrical signal from the signal source into the internal circuit of the filter, reducing signal reflection during transmission, improving signal transmission efficiency, ensuring that the power output from the signal source is transmitted to the filter to the maximum extent, avoiding signal power loss and waveform distortion. Furthermore, the input copper plate 5 interacts with other components inside the filter, participating in the electromagnetic coupling process. Slight changes in the terminal... The relative position between the coupling tuning screw 206 and the input copper plate 5 can make the passband of the filter flatter, enhancing the suppression capability of high-frequency signals in a specific frequency band. Then, after the signal is processed inside the filter, the pure signal of the specific frequency band interference signal is filtered out and transmitted to the subsequent circuit or device through the output copper plate 6 and the output connector 401. This ensures that the filtered signal is output smoothly and stably from the filter and enters the subsequent processing stage, completing the connection of the entire signal processing link. The output copper plate 6 is the same as the input copper plate 5 and has the same function. The output core rod 403 can be better connected to the output copper plate 6, which facilitates stable signal output.

[0024] It should also be noted that multiple port coupling tuning screws 206 are provided above the input copper plate 5 and the output copper plate 6. The port coupling tuning screws 206 closer to the input copper plate 5 and the output copper plate 6 can deepen and enhance the coupling effect, while the port coupling tuning screws 206 slightly further away from the input copper plate 5 and the output copper plate 6, that is, closer to the middle part of the cavity 1, can deepen and weaken the coupling. Tap coupling is achieved through this closed-loop design, and the strength of the tap can be freely adjusted. The conventional tap coupling copper plate is replaced with a closed-loop design for the input copper plate 5 and the output copper plate 6, and port coupling tuning screws 206 are used at corresponding positions on the cover plate 2 to enhance or weaken the coupling. That is, the port coupling tuning screws 206 closer to the connector end will make the coupling value stronger, and the port coupling tuning screws 206 further away from the connector end will make the coupling value weaker, thus making the product performance relatively consistent.

[0025] Example 2: Refer to Figures 1-8 A closed-loop ANT tap structure includes a cavity 1, and an input connector 301 and an output connector 401 respectively disposed on both sides of the cavity 1. The ends of the input connector 301 and the output connector 401 disposed inside the cavity 1 are respectively connected to an input core rod 303 and an output core rod 403. Two first support parts 102 are fixedly connected to the inner side wall of the cavity 1, and two second support parts 103 are fixedly disposed inside the bottom of the cavity 1. A limiting part 104 is provided between the two first support parts 102 and the two second support parts 103. An input copper plate 5 and an output copper plate 6 are both disposed inside the cavity 1, and the input copper plate 5 and the output copper plate 6 respectively cooperate with the input core rod 303 and the output core rod 403. A cover plate 2 is disposed on the cavity 1, and a port coupling tuning screw 206 is provided on the cover plate 2.

[0026] Reference Figures 2-8 The input copper sheet 5 is disposed on the first support part 102 and the second support part 103 near the end of the input core rod 303, and the output copper sheet 6 is disposed on the first support part 102 and the second support part 103 near the end of the output core rod 403. The limiting parts 104 located on both sides of the cavity 1 are respectively inserted into the input copper sheet 5 and the output copper sheet 6.

[0027] Reference Figures 2-8 The first support portion 102 and the second support portion 103 are both provided with mounting holes 105, and the first support portion 102 and the second support portion 103 are both provided with annular support members 504 corresponding to the mounting holes 105. The input copper sheet 5 and the output copper sheet 6 are both placed on the annular support members 504.

[0028] Reference Figures 2-8Both the input copper plate 5 and the output copper plate 6 are provided with through holes 502 corresponding to the positions of the mounting holes 105. Both the input copper plate 5 and the output copper plate 6 are connected with copper plate fixing screws 505. The copper plate fixing screws 505 pass through the through holes 502 and the annular support 504 in sequence and are connected in the mounting holes 105.

[0029] In this embodiment, when installing the input copper sheet 5 and the output copper sheet 6, firstly, place the annular support 504 at the position corresponding to the mounting hole 105. Then, place the input copper sheet 5 and the output copper sheet 6 on the annular support 504, and simultaneously insert the input copper sheet 5 and the output copper sheet 6 into the limiting part 104, so that the through holes 502 on the input copper sheet 5 and the output copper sheet 6 correspond to the annular support 504. Then, install the copper sheet fixing screws 505 to fix the input copper sheet 5 and the output copper sheet 6, thus completing the installation of the input copper sheet 5 and the output copper sheet 6. It should be noted that the annular support 504 and the copper sheet fixing screws... All components 505 are made of non-metallic materials. Specifically, the annular support 504 and the copper sheet fixing screw 505 are both made of non-metallic materials. The annular support 504 is made of PEI material, and the copper sheet fixing screw 505 is made of PEEK material. Non-metallic materials have good electrical insulation properties and will not introduce additional electromagnetic interference or change the electromagnetic environment of the input copper sheet 5 and the output copper sheet 6 during use. In filters, which are sensitive to the electromagnetic environment and require precise control of signal transmission and filtering effect, non-metallic components will not interfere with the electrical path, which helps to maintain a stable signal transmission state and ensure the normal realization of the filtering function.

[0030] Reference Figure 6 and Figure 7 Both the input copper sheet 5 and the output copper sheet 6 are provided with welding grooves 501. One end of the input core rod 303, which is placed inside the cavity 1, is connected to the welding groove 501 on the input copper sheet 5, and the other end of the output core rod 403, which is placed inside the cavity 1, is connected to the welding groove 501 on the output copper sheet 6. The welding grooves 501 make it easy for the input core rod 303 and the output core rod 403 to be connected to the input copper sheet 5 and the output copper sheet 6, thus facilitating their use.

[0031] Example 3: A closed-loop ANT tap structure, which is basically the same as Example 2, but further, an input fixing plate 3 and an output fixing plate 4 are respectively connected to the outer walls of both sides of the cavity 1. The input connector 301 is fixedly connected to the input fixing plate 3, and the output connector 401 is fixedly connected to the output fixing plate 4. The input fixing plate 3 is provided with an input fixing screw 302, and the output fixing plate 4 is provided with an output fixing screw 402. The input fixing plate 3 and the output fixing plate 4 are respectively connected to the outer walls of both sides of the cavity 1 by the input fixing screw 302 and the output fixing screw 402.

[0032] In this embodiment, when installing the input fixing plate 3 and the output fixing plate 4, the input fixing plate 3 and the output fixing plate 4 are first attached to the outer walls of both sides of the cavity 1. Then, the input fixing plate 3 is installed on the outer wall of the cavity 1 by the input fixing screw 302, and the output fixing plate 4 is installed on the other outer wall of the cavity 1 by the output fixing screw 402. At the same time, the input core rod 303 and the output core rod 403 are respectively inserted into the cavity 1 and connected to the input copper sheet 5 and the output copper sheet 6, thereby forming a complete passage structure.

[0033] Both the cavity 1 and the limiting part 104 are provided with connecting holes 101. The cover plate 2 is connected with a locking screw 201. The bottom of the locking screw 201 passes through the cover plate 2 and is connected in the connecting hole 101. Both the input copper plate 5 and the output copper plate 6 are provided with recessed holes 503. The limiting part 104 is inserted into the recessed hole 503.

[0034] By passing the locking screw 201 through the cover plate 2 and connecting it to the connecting hole 101 on the cavity 1, the cover plate 2 can be fixed. The limiting part 104 is also provided with a connecting hole 101 for connecting the locking screw 201, which can improve the fixing effect of the cover plate 2 and ensure the sealing performance between the cavities 1 of the cover plate 2.

[0035] Multiple port coupling tuning screws 206 are provided. One end of each port coupling tuning screw 206 inside the cavity 1 is positioned above the input copper plate 5 and the output copper plate 6. Each port coupling tuning screw 206 is provided with a port coupling tuning nut 207, which abuts against the top outer wall of the cover plate 2.

[0036] The port coupling tuning nut 207 can be rotated to adjust the port coupling tuning screw 206. When loosened, the position of the port coupling tuning screw 206 can be adjusted to enhance or weaken the coupling. That is, the port coupling tuning screw 206 closer to the connector end will make the coupling value stronger, and the port coupling tuning screw 206 farther away from the connector end will make the coupling value weaker, thus making the product indicators relatively consistent. When the port coupling tuning nut 207 is tightened, the port coupling tuning screw 206 can be fixed for easy use.

[0037] The cover plate 2 is also provided with multiple frequency tuning screws 202 and auxiliary tuning screws 204. The multiple frequency tuning screws 202 and auxiliary tuning screws 204 are arranged in an alternating manner. Frequency tuning nuts 203 and auxiliary tuning nuts 205 are respectively connected to the frequency tuning screws 202 and auxiliary tuning screws 204. The frequency tuning nuts 203 and auxiliary tuning nuts 205 abut against the top outer wall of the cover plate 2.

[0038] Reference Figures 2-4The cavity 1 contains a resonant post 106, and the resonant post 106 has a resonant hole 107. One end of the frequency tuning screw 202, which is located inside the cavity 1, is connected to the resonant hole 107. The auxiliary tuning screw 204 extends into the cavity 1 to a greater depth than the frequency tuning screw 202 extends into the cavity 1. In this application, the electromagnetic environment around the resonant column 106 can be changed by setting the frequency tuning screw 202 and the auxiliary tuning screw 204, thereby fine-tuning the resonant frequency of the resonant column 106. Specifically, by loosening the frequency tuning nut 203, the position of the frequency tuning screw 202 within the resonant hole 107 on the resonant column 106 can be adjusted. After adjustment, the frequency tuning nut 203 is tightened so that it abuts against the outer wall of the cover plate 2, thereby fixing the frequency tuning screw 202. Loosening the auxiliary tuning nut 205 can adjust the position of the auxiliary tuning screw 204. After adjustment, the auxiliary tuning nut 205 is tightened so that it abuts against the top outer wall of the cover plate 2, thereby fixing the auxiliary tuning screw 204.

[0039] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A closed-loop ANT tap structure, comprising a cavity (1), characterized in that, Also includes: An input connector (301) and an output connector (401) are respectively set on both sides of the cavity (1). The input connector (301) and the output connector (401) are respectively connected to an input core rod (303) and an output core rod (403) at one end inside the cavity (1). Both first support parts (102) are fixedly connected to the inner sidewall of the cavity (1); Two second support parts (103) are fixedly installed inside the bottom of the cavity (1), and a limiting part (104) is provided between the two first support parts (102) and the two second support parts (103). The input copper plate (5) and the output copper plate (6) are both set inside the cavity (1), and the input copper plate (5) and the output copper plate (6) are respectively matched with the input core rod (303) and the output core rod (403); A cover plate (2) is provided on the cavity (1), and a port coupling tuning screw (206) is provided on the cover plate (2).

2. The closed-loop ANT tap structure according to claim 1, characterized in that, The input copper plate (5) is disposed on the first support part (102) and the second support part (103) near the input core rod (303), and the output copper plate (6) is disposed on the first support part (102) and the second support part (103) near the output core rod (403). The limiting part (104) located on both sides of the cavity (1) is respectively inserted into the input copper plate (5) and the output copper plate (6).

3. The closed-loop ANT tap structure according to claim 1, characterized in that, The first support part (102) and the second support part (103) are both provided with mounting holes (105), and the first support part (102) and the second support part (103) are both provided with annular support members (504) corresponding to the mounting holes (105). The input copper sheet (5) and the output copper sheet (6) are both placed on the annular support member (504).

4. The closed-loop ANT tap structure according to claim 3, characterized in that, Both the input copper plate (5) and the output copper plate (6) are provided with through holes (502) corresponding to the position of the mounting hole (105). Both the input copper plate (5) and the output copper plate (6) are connected with copper plate fixing screws (505). The copper plate fixing screws (505) pass through the through holes (502) and the annular support (504) in sequence and are connected in the mounting hole (105).

5. The closed-loop ANT tap structure according to claim 4, characterized in that, Both the input copper sheet (5) and the output copper sheet (6) are provided with welding grooves (501). One end of the input core rod (303) placed in the cavity (1) is connected to the welding groove (501) on the input copper sheet (5), and one end of the output core rod (403) placed in the cavity (1) is connected to the welding groove (501) on the output copper sheet (6).

6. The closed-loop ANT tap structure according to claim 1, characterized in that, An input fixing plate (3) and an output fixing plate (4) are respectively connected to the outer walls of the two sides of the cavity (1). The input connector (301) is fixedly connected to the input fixing plate (3), and the output connector (401) is fixedly connected to the output fixing plate (4). The input fixing plate (3) is provided with an input fixing screw (302), and the output fixing plate (4) is provided with an output fixing screw (402). The input fixing plate (3) and the output fixing plate (4) are respectively connected to the outer walls of the two sides of the cavity (1) by the input fixing screw (302) and the output fixing screw (402).

7. The closed-loop ANT tap structure according to claim 1, characterized in that, Both the cavity (1) and the limiting part (104) are provided with connecting holes (101). The cover plate (2) is connected with a locking screw (201). The bottom of the locking screw (201) passes through the cover plate (2) and is connected in the connecting hole (101). Both the input copper plate (5) and the output copper plate (6) are provided with recessed holes (503). The limiting part (104) is inserted into the recessed hole (503).

8. The closed-loop ANT tap structure according to claim 1, characterized in that, The port coupling tuning screw (206) is provided in multiple ways. One end of each of the port coupling tuning screws (206) is located inside the cavity (1) and is positioned above the input copper plate (5) and the output copper plate (6). Each of the port coupling tuning screws (206) is provided with a port coupling tuning nut (207), which abuts against the top outer wall of the cover plate (2).

9. A closed-loop ANT tap structure according to claim 8, characterized in that, The cover plate (2) is also provided with a plurality of frequency tuning screws (202) and auxiliary tuning screws (204). The plurality of frequency tuning screws (202) and auxiliary tuning screws (204) are arranged in an alternating manner. Frequency tuning nuts (203) and auxiliary tuning nuts (205) are respectively connected to the frequency tuning screws (202) and auxiliary tuning screws (204). The frequency tuning nuts (203) and auxiliary tuning nuts (205) abut against the top outer wall of the cover plate (2).

10. A closed-loop ANT tap structure according to claim 9, characterized in that, The cavity (1) is provided with a resonant post (106), and the resonant post (106) is provided with a resonant hole (107). One end of the frequency tuning screw (202) is placed in the cavity (1) and connected to the resonant hole (107). The depth of the auxiliary tuning screw (204) extending into the cavity (1) is greater than the depth of the frequency tuning screw (202) extending into the cavity (1).

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