An adjustable waveguide filter and its tuning method

Abstract

The present invention discloses an adjustable waveguide filter and a tuning method thereof. The filter includes a box body, an upper cover plate fixed on the box body, a driving assembly and at least one driving plate installed in the box body. A plurality of resonant cavities are arranged in the box body. A plurality of tuning posts extending into the resonant cavities are fixed on the upper cover plate. One tuning post corresponds to one resonant cavity. The driving plate is connected to the driving assembly, and a plurality of coupling rods are fixed on the driving plate. Driven by the driving assembly, the driving plate drives the coupling rods to extend into the resonant cavities to couple with the corresponding resonant cavities and tuning posts. The present invention changes the traditional spiral tuning trajectory into a linear tuning trajectory, making it possible for multiple waveguide resonant cavities to share a linear motor, significantly reducing the cost and having higher reliability.

Description

Technical Field

[0001] The present invention relates to a waveguide filter, and in particular to an adjustable waveguide filter with low cost and high product reliability and a tuning method thereof. Background Art

[0002] For the tuning of traditional waveguide filters, it is usually achieved by adjusting the depth of each tuning screw extending into the waveguide resonator cavity to control the resonance frequency. Generally, one tuning screw corresponds to one motor drive.

[0003] For example, Chinese Patent CN204130671U discloses a structure applicable to a cavity electrically tunable filter. A metal cylinder is provided in each resonant cavity, and each tuning cylinder is connected to an automatic lifting mechanism. The distance between the lower end surface of the tuning cylinder and the upper end surface of the metal cylinder is controlled by the automatic lifting mechanism to achieve tuning.

[0004] This tuning method requires a large number of motors, high precision requirements, and high costs in the electrical tuning design. Summary of the Invention

[0005] The object of the present invention is to overcome the defects of the prior art and provide an adjustable waveguide filter with low cost and high product reliability.

[0006] To achieve the above object, the present invention proposes the following technical solution: An adjustable waveguide filter includes an upper cover plate, a box body, a driving component and a driving board installed in the box body. A plurality of resonant cavities are provided in the box body. The upper cover plate is fixed on the box body, and a plurality of tuning columns extending into the resonant cavities are fixed on the upper cover plate. One tuning column corresponds to one resonant cavity. The adjustable waveguide filter further includes at least one driving board installed in the box body. The driving board is connected to the driving component, and a plurality of coupling rods are fixed on the driving board. Each coupling rod corresponds to one resonant cavity and the tuning column in the resonant cavity. Driven by the driving component, the driving board drives the coupling rods on the driving board to extend into the resonant cavities to couple with the corresponding resonant cavities and tuning columns.

[0007] Preferably, the length of the tuning column extending into the resonant cavity is not adjustable.

[0008] Preferably, the adjustable waveguide filter further includes a driving control component connected to the driving component. The driving control component includes a socket, a first circuit board and a second circuit board. The socket is installed on the first circuit board. The first circuit board is installed on the box body and electrically connected to the second circuit board. The second circuit board is installed in the box body and electrically connected to the driving component.

[0009] Preferably, the first circuit board and the second circuit board, and the second circuit board and the driving component are electrically connected by cables.

[0010] Preferably, the driving assembly includes a motor, a rotating shaft connected to the motor, and a driving ring movably sleeved on the rotating shaft, and the driving ring is connected to the driving plate.

[0011] Preferably, the coupling rod includes a support rod and metal particles. One end of the support rod is fixed on the driving plate, and the other end fixes the metal particles; the metal particles are located at the side ends of the resonant cavity and the tuning post.

[0012] Preferably, the support rod is in an L shape bent towards the resonant cavity.

[0013] Preferably, the metal particles are provided with grooves.

[0014] Preferably, the grooves on the metal particles are provided at the front end and both side ends thereof.

[0015] Preferably, the tunable waveguide filter further includes a lower cover plate fixed on the lower end face of the box body.

[0016] Preferably, the resonant cavity is formed on the upper end face of the box body, the driving assembly and the driving plate are installed on the lower end face of the box body, the coupling rod on the driving plate passes through the lower end face to the upper end face, and its front end extends into the resonant cavity from the side end of the resonant cavity.

[0017] The present invention also provides another technical solution: a tuning method based on the above tunable waveguide filter, including: the driving plate drives the coupling rod to move from the side end of the resonant cavity into the resonant cavity under the drive of the driving assembly, and as the coupling rod moves, the coupling rod is coupled with the corresponding resonant cavity and tuning post to adjust the resonant frequency.

[0018] The tuning method specifically includes: the socket transmits the driving instruction to the second circuit board through the first circuit board, the second circuit board controls the motor to work after receiving the instruction, the motor drives the rotating shaft to rotate, the rotation of the rotating shaft drives the driving ring to move left and right, the driving plate drives the coupling rod to extend into the resonant cavity from the side end of the resonant cavity under the drive of the driving ring, and as the coupling rod moves, the coupling rod is coupled with the corresponding resonant cavity and tuning post to adjust the resonant frequency.

[0019] Furthermore, when the resonant frequency reaches the required value, the coupling rod stops moving.

[0020] The beneficial effects of the present invention are:

[0021] 1. By using a coupling rod to move from the side of the resonant cavity into the resonant cavity and gradually approach the tuning stud fixed in the resonant cavity, as the coupling rod moves, the coupling rod couples with both the resonant cavity and the tuning stud. Since this tuning method changes the traditional spiral tuning trajectory into a linear tuning trajectory, it makes it possible for multiple waveguide resonant cavities to share a linear micromotor, significantly reducing costs and having higher reliability.

[0022] 2. Since the coupling rod is formed by supporting metal particles with a low-loss dielectric, this can effectively reduce the decrease in the Q value of the waveguide resonant cavity.

[0023] 3. Since the tuning rod is vertically inserted into the waveguide resonant cavity, the slot size on the waveguide wall is small and the leakage is less. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 is a schematic perspective view of the assembled structure of the present invention;

[0025] Figure 2 is a schematic perspective view of the assembled structure of the present invention except for the upper cover plate;

[0026] Figure 3 is a schematic perspective view of the assembled structure of the present invention except for the lower cover plate;

[0027] Figure 4 and Figure 5 is a schematic exploded view of the present invention in different directions;

[0028] Figure 6 is a schematic cross-sectional view of the present invention;

[0029] Figure 7 and Figure 8 are schematic views of the coupling rod of the present invention from different perspectives.

[0030] REFERENCE SIGNS:

[0031] 1. Upper cover plate, 2. Box body, 3. Driving plate, 4. Lower cover plate, 5. Tuning column, 6. Resonant cavity, 7. Socket installation part, 8. Motor, 9. Rotating shaft, 10. Driving ring, 11. Motor accommodation hole, 12. Connecting part, 13. Coupling rod, 131. Support rod, 132. Metal particle, 133. Groove, 134. Receiving hole, 14. Through hole, 15. Socket, 16. First circuit board, 17. Second circuit board. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0032] The technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention.

[0033] An adjustable waveguide filter disclosed by the present invention realizes frequency adjustment of the entire filter to a required value by changing the tuning trajectory of the waveguide filter, driving all coupling rods with one motor, reducing costs and improving product reliability.

[0034] As shown in Figures 1 to 6 An adjustable waveguide filter disclosed by an embodiment of the present invention includes an upper cover plate 1, a box body 2, two sets of driving components, two driving plates 3, a driving control component and a lower cover plate 4. Among them, the upper cover plate 1 is fixed on the upper end surface of the box body 2, such as by screws, and multiple tuning columns 5 perpendicular to the upper cover plate 1 are fixed on the upper cover plate 1 (the tuning columns are fixedly held on the upper cover plate and immovable), and the length of the tuning columns 5 extending into the box body remains unchanged. Multiple resonant cavities 6 are provided at the upper end of the box body 2, and the tuning columns 5 on the upper cover plate 1 vertically extend into the resonant cavities 6, and one tuning column 5 corresponds to one resonant cavity 6. Generally, the tuning column 5 is located at the axial center position of the resonant cavity 6. In addition, a socket mounting portion 7 is further provided on the side of the upper end surface of the box body 2.

[0035] Two sets of the above driving components are installed at the lower end of the box body 2, and the two sets of driving components are symmetric along the X axis of the box body. In this embodiment, the driving component includes a motor 8, a rotating shaft 9 and a driving ring 10. The motor 8 is fixed at the lower end of the box body 2, the rotating shaft 9 is connected to the motor 8, the driving ring 10 is movably sleeved on the rotating shaft 9, the motor 8 drives the rotating shaft 9 to rotate, and the rotation of the rotating shaft 9 drives the driving ring 10 to move left and right along the X axis.

[0036] The driving plate 3 is connected to the driving component, and follows the driving ring 10 to move left and right synchronously along the X axis under the drive of the driving component. In this embodiment, the driving plate 3 is installed at the lower end of the box body 2 and is accommodated in the box body 2. Corresponding to the two sets of driving components, two driving plates 3 are installed in the box body 3, and one set of driving components is electrically connected to one driving plate 3 through a cable, that is, one motor 8 drives one driving plate 3. In this embodiment, a motor accommodation hole 11 for the driving component to pass through is provided on the driving plate 3. When the driving plate 3 is installed at the lower end of the box body 2, the driving component installed at the lower end passes through the motor accommodation hole 11.

[0037] As shown in Figure 4 A connecting portion 12 located on the motor accommodation hole 11 also extends out of the driving plate 3, and the connecting portion 12 is connected to the motor rotating shaft 9, thereby realizing the connection between the driving plate 3 and the motor 8.

[0038] Multiple coupling rods 13 are fixed on the driving board 3. A through hole 14 penetrating the upper end face and the lower end face is arranged in the box body 2. One through hole 14 corresponds to one coupling rod 13. After the driving board 3 is installed into the box body 2, the coupling rod 13 extends from the lower end of the box body 2 to the upper end. After extending to the upper end, its front end is close to the side end of the resonant cavity 6 in the initial state. The coupling rod 13 can also be integrally formed with the driving board 3 directly as long as the two are fixedly connected.

[0039] Different from the existing tuning rod structure, in combination Figure 7 and Figure 8 As shown, the coupling rod 13 of the present invention includes a low-loss support rod 131 and metal particles 132. One end of the support rod 131 is fixed on the driving board 3, and the other end is fixed with the metal particles 132. The metal particles 132 can be received in the end of the support rod 131. For example, a receiving hole 134 for accommodating the metal particles 132 is arranged at the end of the support rod 131; or it can be directly fixed on the end of the support rod 131 as long as the support rod 131 supports the metal particles 132 to move.

[0040] Preferably, in order to enhance the holding stability between the support rod 131 and the metal particles 132, grooves 133 are provided at the rear end and both sides of the metal particles 132. When the support rod 131 is formed, a part of the support rod 131 is formed in the above grooves 133, so that the support rod 131 and the metal particles 132 are stably held. The coupling rod 13 of the present invention is formed by using a low-loss medium to support metal microparticles, which can effectively reduce the reduction of the Q value of the waveguide resonant cavity. In addition, since the volume of the metal particles is small, fine tuning can be performed during tuning, so the accuracy requirement during tuning is reduced, and at the same time, the reduction of metal materials used makes the cost of the product reduced.

[0041] In this embodiment, the support rod 131 has an L-shaped structure bent towards the resonant cavity 6.

[0042] The control component is connected to the driving component and is used to control the operation of the driving component. In this embodiment, the control component includes a socket 15, a first circuit board 16 and a second circuit board 17. Among them, the socket 15 is installed on the first circuit board 16. After the two are assembled, the first circuit board 16 is then installed on the socket installation part 7 of the box body 2. The first circuit board 16 is electrically connected to the second circuit board 17 through a cable; the second circuit board 17 is installed in the box body 2 and is located between the driving board 3 and the lower cover plate 4. The second circuit board 17 is electrically connected to the driving component through a cable.

[0043] The lower cover plate 4 is fixed on the lower end face of the box body 2, such as by screws. It and the upper cover plate 1 encapsulate other components of the present invention in the box body 2.

[0044] The working principle of the present invention is as follows: When the socket 15 receives a driving instruction, the socket 15 transmits the driving instruction to the second circuit board 17 through the first circuit board 16. After receiving the instruction, the second circuit board 17 controls the motor 8 to start working. The motor 8 drives the rotating shaft 9 to rotate, and the rotating shaft 9 drives the driving ring 10 to move left and right. The driving plate 3 moves synchronously as a whole under the drive of the driving ring 10, thereby driving the coupling rod 13 to gradually extend into the resonant cavity 6 from the side end of the resonant cavity 6. As the coupling rod 13 moves, the coupling rod 13 couples with the corresponding resonant cavity 6 and tuning post 5 to adjust the resonant frequency. When the metal particles 132 move deeper into the resonant cavity 6, the resonant frequency becomes smaller; conversely, when moving away from the resonant cavity 6, the resonant frequency becomes larger.

[0045] Based on the tunable waveguide filter disclosed in the above embodiment, the present invention correspondingly discloses a tuning method for a tunable waveguide filter, including: driving the driving plate 3 to move as a whole by a driving component. Under the drive of the driving component, the driving plate 3 drives the coupling rod 13 to move from the side of the resonant cavity 6 into the resonant cavity 6. As the coupling rod 13 moves, the coupling rod 13 couples with the corresponding resonant cavity 6 and tuning post 5 to adjust the resonant frequency.

[0046] Specifically, when the socket 15 receives a driving instruction, the socket 15 transmits the driving instruction to the second circuit board 17 through the first circuit board 16. After receiving the driving instruction, the second circuit board 17 controls the motor 8 to start working. The motor 8 drives the rotating shaft 9 to rotate, and the rotating shaft 9 drives the driving ring 10 to move left and right. The driving plate 3 moves synchronously as a whole under the drive of the driving ring 10, thereby driving the coupling rod 13 to gradually extend into the resonant cavity 6 from the side end of the resonant cavity 6, and thus gradually approaching the tuning screw post 5 in the resonant cavity 6. As the coupling rod 13 moves, the coupling rod 13 couples with the corresponding resonant cavity 6 and tuning post 5 to adjust the resonant frequency. When the metal particles 132 move deeper into the resonant cavity 6, the resonant frequency becomes smaller; conversely, when moving away from the resonant cavity 6, the resonant frequency becomes larger.

[0047] When the frequency adjustment reaches a required value, the movement of the coupling rod 13 stops. Specifically, the socket 15 sends a stop instruction to the first circuit board 16, and the first circuit board 16 transmits the stop instruction to the second circuit board 17. After receiving the stop instruction, the second circuit board 17 controls the motor 8 to stop working, and further controls the driving plate 3 to stop moving, and the coupling rod 13 also stops moving.

[0048] Since the spiral trajectory during tuning in the present invention is changed into a straight-line trajectory, it is convenient to use a linear motor to drive the coupling rod 13 to perturb and tune the frequency in the waveguide resonator 6, and it is realized that all the coupling rods 13 are driven by one motor 8 to adjust the frequency of the entire filter to the required value. Compared with the traditional method that each resonator 6 must be equipped with a driving motor, through the solution of the present invention, the number of driving motors used is significantly reduced and the cost is significantly lowered. Today, with increasingly stringent suppression requirements and an increasing number of resonators, the application has more advantages.

[0049] The technical content and technical features of the present invention have been disclosed above. However, those skilled in the art may still make various substitutions and modifications that do not deviate from the spirit of the present invention based on the teachings and disclosures of the present invention. Therefore, the protection scope of the present invention should not be limited to the content disclosed in the embodiments, but should include various substitutions and modifications that do not deviate from the present invention and are covered by the claims of this patent application.

Claims

1. An adjustable waveguide filter, comprising an upper cover plate, a box body and a driving assembly installed in the box body. A plurality of resonant cavities are arranged in the box body. The upper cover plate is fixed on the upper end surface of the box body, and a plurality of tuning posts extending into the resonant cavities are fixed on the upper cover plate. One tuning post corresponds to one resonant cavity. Characterized in that, The adjustable waveguide filter further includes at least one driving plate installed in the box body. The driving plate is connected to the driving assembly, and a plurality of coupling rods are fixed on the driving plate. Each coupling rod corresponds to one resonant cavity and the tuning post in the resonant cavity. Driven by the driving assembly, the driving plate drives the plurality of coupling rods on the driving plate to move into the resonant cavity from the side end of the resonant cavity, and couple with the corresponding resonant cavity and tuning post.

2. The adjustable waveguide filter according to claim 1, Characterized in that, The length of the tuning post extending into the resonant cavity is not adjustable.

3. The adjustable waveguide filter according to claim 2, Characterized in that, The adjustable waveguide filter further includes a driving control assembly connected to the driving assembly. The driving control assembly includes a socket, a first circuit board and a second circuit board. The socket is installed on the first circuit board. The first circuit board is installed on the box body and electrically connected to the second circuit board. The second circuit board is installed in the box body and electrically connected to the driving assembly.

4. The adjustable waveguide filter according to claim 3, Characterized in that, The first circuit board and the second circuit board, and the second circuit board and the driving assembly are electrically connected by cables.

5. The adjustable waveguide filter according to claim 3, Characterized in that, The driving assembly includes a motor, a rotating shaft connected to the motor, and a driving ring movably sleeved on the rotating shaft. The driving ring is connected to the driving plate.

6. The adjustable waveguide filter according to claim 1, Characterized in that, The coupling rod includes a support rod and a metal particle. One end of the support rod is fixed on the driving plate, and the other end fixes the metal particle. The metal particle is located at the side end of the resonant cavity and the tuning post.

7. The adjustable waveguide filter according to claim 6, Characterized in that, The support rod is in an L shape bent towards the resonant cavity.

8. A tuning method for the adjustable waveguide filter according to claim 5 above, Characterized in that, The tuning method includes: driven by the driving assembly, the driving plate drives the coupling rod to move into the resonant cavity from the side end of the resonant cavity. As the coupling rod moves, the coupling rod couples with the corresponding resonant cavity and tuning post to adjust the resonant frequency.

9. The tuning method for the adjustable waveguide filter according to claim 8, the tuning method Includes: The socket transmits the driving instruction to the second circuit board through the first circuit board. After receiving the instruction, the second circuit board controls the motor to work. The motor drives the rotating shaft to rotate. The rotation of the rotating shaft drives the driving ring to move left and right. Driven by the driving ring, the driving plate drives the coupling rod to extend into the resonant cavity from the side end of the resonant cavity. As the coupling rod moves, the coupling rod couples with the corresponding resonant cavity and tuning post to adjust the resonant frequency.

10. The tuning method of the tunable waveguide filter according to claim 9, characterized in that, when the resonant frequency reaches the required value, the coupling rod stops moving.

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