filter

Abstract

This application relates to the field of filtering device technology, and provides a filter comprising three resonant cavities, three resonators, and a coupling plate arranged side-by-side. The three resonant cavities are, in sequence, a first resonant cavity, a second resonant cavity, and a third resonant cavity. The three resonators are correspondingly disposed within the three resonant cavities. The coupling plate includes a first piece spanning the three resonant cavities and located on one side of each resonator. A second piece and a third piece, bent and grounded, are respectively provided at both ends of the first piece. The first piece also has a clearance section, which is further away from the resonators than the first piece and is arranged parallel to the inner wall of the filter. This filter avoids the resonant frequency of the coupling plate itself affecting the passband of the filter by cross-coupling the first piece with the second and third pieces, enabling the three resonant cavities arranged side-by-side to achieve the beneficial effect of a single zero point.

Description

Technical Field

[0001] This application relates to the field of filtering device technology, and more particularly to a filter. Background Technology

[0002] A filter is a frequency-selective device and an indispensable part of communication equipment. In traditional filter design, symmetrical zeros are usually generated using metal probes, for example... Figure 1 In a linear cavity filter, a metal probe 2' is inserted through one of the four adjacent sub-resonant cavities 1'. However, the metal probe 2' essentially functions as a capacitor and has its own resonant frequency. When the metal probe 2' is too long, its own frequency will affect the filter's passband. For example... Figure 2 The peak S in the waveform is the harmonic caused by the excessive length of the metal probe 2'.

[0003] Therefore, there is an urgent need in the market for a new type of filter to solve the harmonic problem caused by excessively long metal probes in the existing straight-cavity filters. Summary of the Invention

[0004] In order to solve the above-mentioned technical problems, or at least partially solve the above-mentioned technical problems, this application provides a filter.

[0005] The filter provided in this application includes three resonant cavities, three resonators, and a coupling plate arranged side by side;

[0006] The three resonant cavities are, in order, the first resonant cavity, the second resonant cavity, and the third resonant cavity;

[0007] The three resonators are respectively disposed in the three resonant cavities;

[0008] The coupling plate includes a first plate body that spans across the three resonant cavities and is located on the same side of each of the resonators;

[0009] The first piece has a second piece and a third piece that are bent and grounded at both ends;

[0010] The first sheet also has a clearance section, which is located further away from the resonator than the first sheet and is arranged parallel to the inner wall of the filter.

[0011] In one possible design, the second plate is connected to the cavity wall of the first resonant cavity and grounded;

[0012] The third plate is connected to the cavity wall of the third resonant cavity and grounded, or connected to the resonator inside the third resonant cavity and grounded.

[0013] In one possible design, the bottom wall of the first resonant cavity is provided with a first protrusion, and the second plate is grounded through the first protrusion.

[0014] In one possible design, the height of the first protrusion is denoted as H1, and the distance between the first protrusion along its width and the resonator in the first resonant cavity is denoted as L1.

[0015] Among them, the size of H1 is negatively correlated with the coupling effect of the coupling plate;

[0016] The absolute value of the difference between H1 and L1 is negatively correlated with the coupling effect of the coupling plate.

[0017] In one possible design, the bottom wall of the third resonant cavity is provided with a second protrusion, and the third plate is grounded through the second protrusion.

[0018] In one possible design, the height of the second protrusion is denoted as H2, and the distance between the second protrusion along its width and the resonator in the third resonant cavity is denoted as L2.

[0019] The size of H2 is positively correlated with the coupling effect of the coupling plate;

[0020] The absolute value of the difference between H2 and L2 is negatively correlated with the coupling effect of the coupling plate.

[0021] In one possible design, the third body is grounded to the resonator within the third resonant cavity.

[0022] In one possible design, the first sheet also includes a bent section;

[0023] The bending section is disposed between the second sheet and the avoidance section and / or between the third sheet and the avoidance section.

[0024] In one possible design, the spacing between the bent segment and the corresponding resonator in the resonant cavity is negatively correlated with the amount of coupling between two adjacent resonant cavities.

[0025] In one possible design, the grounding terminals of the second and third plates are also provided with annular washers.

[0026] The technical solution provided in this application has the following advantages compared with the prior art:

[0027] When the resonant filter provided in this application embodiment is assembled and used, the coupling plate can be grounded by the second and third plates set at both ends of its first plate, respectively. Thus, the cross coupling of the first plate with the second and third plates can avoid the resonant frequency of the coupling plate itself from affecting the passband of the filter, so that the three resonant cavities in the filter that are conducted side by side can achieve the beneficial effect of a single zero point. Attached Figure Description

[0028] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0029] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0030] Figure 1 This is a schematic diagram of a straight-line cavity filter in the prior art;

[0031] Figure 2 The S-parameter diagram of a straight-line cavity filter in the prior art;

[0032] Figure 3 This is a schematic diagram of the filter structure provided in an embodiment of this application;

[0033] Figure 4 for Figure 3 Local structural diagram;

[0034] Figure 5 This is a first structural diagram of the coupling plate in the filter provided in the embodiments of this application;

[0035] Figure 6 S-parameter diagram of the filter provided in the embodiments of this application;

[0036] Figure 7 This is a schematic diagram of another filter structure provided in an embodiment of this application;

[0037] Figure 8 for Figure 7 Local structural diagram;

[0038] Figure 9 This is a second structural diagram of the coupling plate in the filter provided in the embodiments of this application.

[0039] Reference numerals: 1. Resonant cavity; 10. Resonator; 11. First resonant cavity; 12. Second resonant cavity; 13. Third resonant cavity; 14. First protrusion; 15. Second protrusion; 2. Coupling plate; 20. Annular washer; 21. First piece; 211. Clearance section; 212. Bending section; 22. Second piece; 23. Third piece. Detailed Implementation

[0040] To better understand the above-mentioned objectives, features, and advantages of this application, the solution of this application will be further described below. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0041] Many specific details are set forth in the following description in order to provide a full understanding of this application, but this application may also be implemented in other ways different from those described herein; obviously, the embodiments in the specification are only some embodiments of this application, and not all embodiments.

[0042] Combination Figures 3 to 9 As shown, this application provides a filter including three resonant cavities 1, three resonators 10, and a coupling plate 2 arranged side by side; the three resonant cavities 1 are, in sequence, a first resonant cavity 11, a second resonant cavity 12, and a third resonant cavity 13; the three resonators 10 are arranged one-to-one in the three resonant cavities 1; the coupling plate 2 includes a first plate body 21 that spans the three resonant cavities 1 and is located on the same side of each resonator 10.

[0043] The first piece 21 has a second piece 22 and a third piece 23 that are bent and grounded at both ends; the first piece 21 also has a clearance section 211, which is farther away from the resonator 10 than the first piece 21 and is arranged parallel to the inner wall of the filter.

[0044] When the filter is assembled and used, the coupling plate 2 can be grounded to the first resonant cavity 11 and the third resonant cavity 13 of the resonant cavity 1 through the second plate 22 and the third plate 23 set at both ends of its first plate 21, respectively. Thus, the cross coupling of the first plate 21 with the second plate 22 and the third plate 23 can avoid the resonant frequency of the coupling plate 2 itself from affecting the passband of the filter, so that the three resonant cavities 1 in the side-by-side conduction of the filter can fully realize the beneficial effect of a single zero point.

[0045] Compared with the filters in the prior art that use metal probes to generate symmetrical zeros, the filter provided in this application embodiment can avoid the generation of harmonics at the resonant frequency of the coupling plate 2 itself by cross-coupling the first plate 21 in the coupling plate 2 with the second plate 22 and the third plate 23 respectively. It has the beneficial effect of enabling the three parallel conducting resonant cavities 1 in the filter to achieve a single zero. Moreover, the above-mentioned avoidance section 211 can be specifically set as a straight section located in the middle of the first plate 21. By setting the avoidance section 211 further away from the resonator 10 than the first plate 21, the internal structure of the filter can be avoided, and the influence of the first plate 21 on the internal structural layout of the filter can be minimized.

[0046] In some specific embodiments, the second piece 22 is connected to the cavity wall of the first resonant cavity 11 and grounded; the third piece 23 is connected to the cavity wall of the third resonant cavity 13 and grounded, or connected to the resonator 10 in the third resonant cavity 13 and grounded.

[0047] Specifically, in combination Figure 4 and Figure 8 To elaborate further, Figure 4 The second piece 22 is connected to the cavity wall of the first resonant cavity 11 and grounded, and the third piece 23 is connected to the cavity wall of the third resonant cavity 13 and grounded. Figure 8 The second piece 22 is connected to the cavity wall of the first resonant cavity 11 and grounded, and the resonator 10 in the third resonant cavity 13 is connected to the third piece 23 and grounded.

[0048] Both of the above-mentioned specific connection methods can achieve a stable grounding connection of the coupling piece 2, and can ensure the cross-coupling effect of the first piece 21 with the second piece 22 and the third piece 23 respectively. Moreover, the function of adjusting the cross-coupling effect can be achieved by adjusting the effective connection length between the second piece 22 and the cavity wall, the effective connection length between the third piece 23 and the cavity wall, or the effective connection length between the third piece 23 and the resonator 10.

[0049] In some specific embodiments, the bottom wall of the first resonant cavity 11 is provided with a first protrusion 14, and the second plate 22 is grounded through the first protrusion 14.

[0050] Specifically, in combination Figure 3 and Figure 4 In further detail, the first protrusion 14 can be configured as a protrusion head integrally connected to the bottom wall of the first resonant cavity 11, and the specific protrusion height of the first protrusion 14 can be pre-designed during manufacturing. Moreover, the specific grounding method of the first protrusion 14 and the second plate 22 can be, but is not limited to, configured as a detachable grounding method by means of screw connection.

[0051] By grounding the second plate 22 to the first protrusion 14 at the bottom wall of the first resonant cavity 11, it has the advantages of simple structure, stable connection, and the ability to adjust the coupling effect of the second plate 22 by changing the preset height of the first protrusion 14 or changing the grounding position of the first protrusion 14 and the second plate 22.

[0052] In some specific embodiments, the height of the first protrusion 14 is denoted as H1, and the distance between the first protrusion 14 along its own width direction and the resonator 10 in the first resonant cavity 11 is denoted as L1; wherein, the size of H1 is negatively correlated with the coupling effect of the coupling plate 2; the absolute value of the difference between H1 and L1 is negatively correlated with the coupling effect of the coupling plate 2.

[0053] Specifically, in combination Figure 4 To explain in more detail, let the height of the first protrusion 14 be denoted as H1. The larger H1 is, the weaker the coupling effect generated by the second piece 22. Let L1 be the distance between the first protrusion 14 along its own width direction and the resonator 10 in the first resonant cavity 11. The smaller the absolute value of L1-H1, the stronger the coupling effect generated by the second piece 22. When L1 equals H1, the coupling effect of the second piece 22 reaches its strongest.

[0054] In some specific embodiments, the bottom wall of the third resonant cavity 13 is provided with a second protrusion 15, and the third plate 23 is grounded through the second protrusion 15.

[0055] Specifically, in combination Figure 4 To elaborate further, similarly, the second protrusion 15 can be configured as a protrusion integrally connected to the bottom wall of the third resonant cavity 13, and the specific protrusion height of the second protrusion 15 can be pre-designed during manufacturing. Furthermore, the specific grounding method of the second protrusion 15 and the third plate 23 can be, but is not limited to, configured as a detachable grounding method by means of screw connection.

[0056] By grounding the third plate 23 and the second protrusion 15 at the bottom wall of the third resonant cavity 13, it has the advantages of simple structure, stable connection, and the ability to adjust the coupling effect of the third plate 23 by changing the preset height of the second protrusion 15 or changing the grounding position of the second protrusion 15 and the third plate 23.

[0057] In some specific embodiments, the height of the second protrusion 15 is denoted as H2, and the distance between the second protrusion 15 along its own width direction and the resonator 10 in the third resonant cavity 13 is denoted as L2; ​​wherein, the size of H2 is positively correlated with the coupling effect of the coupling plate 2; the absolute value of the difference between H2 and L2 is negatively correlated with the coupling effect of the coupling plate 2.

[0058] Specifically, in combination Figure 4To explain in more detail, let the height of the second protrusion 15 be denoted as H2. The larger H2 is, the stronger the coupling effect generated by the third piece 23. Let L2 be the distance between the second protrusion 15 along its own width direction and the resonator 10 in the third resonant cavity 13. The smaller the absolute value of L2-H2, the stronger the coupling effect generated by the third piece 23. When L2 equals H2, the coupling effect of the third piece 23 reaches its strongest.

[0059] In some specific embodiments, the third piece 23 is grounded to the resonator 10 in the third resonant cavity 13.

[0060] Specifically, in combination Figure 7 and Figure 8 To elaborate further, the third piece 23 is specifically connected to the ground of the resonator 10 within the third resonant cavity 13. This eliminates the need for a protruding grounding portion on the inner wall of the third resonant cavity 13. While ensuring the cross-coupling of the first piece 21 with the second piece 22 and the third piece 23 respectively, it also simplifies the internal structure of the third resonant cavity 13. Furthermore, connecting the third piece 23 to the ground of the resonator 10 within the third resonant cavity 13 is equivalent to maximizing the "grounding height H2" of the third piece 23, thereby generating a stronger zero point.

[0061] In some specific embodiments, the first sheet 21 further includes a bending section 212; the bending section 212 is disposed between the second sheet 22 and the clearance section 211 and / or between the third sheet 23 and the clearance section 211.

[0062] Specifically, in combination Figure 4 and Figure 5 To explain in more detail, the first piece 21 is positioned between the second piece 22 and the clearance section 211, and between the third piece 23 and the clearance section 211, by setting two bending sections 212 to avoid the structure at the guide channel between the first resonant cavity 11 and the second resonant cavity 12, and between the second resonant cavity 12 and the third resonant cavity 13. This minimizes the impact of the first piece 21 on the coupling between the first resonant cavity 11, the second resonant cavity 12, and the third resonant cavity 13.

[0063] In some specific implementations, the distance between the bent section 212 and the resonator 10 in the corresponding resonant cavity 1 is negatively correlated with the amount of coupling between two adjacent resonant cavities 1.

[0064] Specifically, in combination Figure 4To elaborate further, the greater the distance between the bent section 212 and the resonator 10 in the corresponding resonant cavity 1, the smaller the coupling between the two resonant cavities 1 adjacent to the bent section 212; the smaller the distance between the bent section 212 and the resonator 10 in the corresponding resonant cavity 1, the greater the coupling between the two resonant cavities 1 adjacent to the bent section 212.

[0065] In some specific embodiments, the grounding terminals of the second piece 22 and the third piece 23 are respectively provided with annular washers. The first protrusion 14 and the top of the first protrusion 15 are provided with mounting holes; the annular washers can be fixedly connected to the first protrusion 14 and the second protrusion 15 by means of screws being inserted and screwed into the mounting holes.

[0066] In some specific embodiments, the annular washer is integrally connected with the second piece 22 and the third piece 23 respectively.

[0067] The coupling piece 2 can be made of copper sheet by stamping process, which makes the annular washer integrated with the second piece 22 and the third piece 23, which has the advantage of facilitating batch production.

[0068] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0069] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments described herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A filter, characterized in that, include: Three resonant cavities (1) are arranged side by side and connected in a conductive manner. The three resonant cavities (1) are, in order, a first resonant cavity (11), a second resonant cavity (12), and a third resonant cavity (13). Three resonators (10) are arranged one-to-one in the three resonant cavities (1); and coupling plate (2), the coupling plate (2) comprising a first plate body (21) spanning the three resonant cavities (1) and located on the same side of each of the resonators (10); The first piece (21) has a second piece (22) and a third piece (23) that are bent and grounded at both ends; The first sheet (21) also has a clearance section (211), which is farther away from the resonator (10) than the first sheet (21) and is arranged parallel to the inner wall of the filter; The second plate (22) is connected to the cavity wall of the first resonant cavity (11) and grounded; The third piece (23) is connected to the cavity wall of the third resonant cavity (13) and grounded, or connected to the resonator (10) inside the third resonant cavity (13) and grounded. The first sheet (21) also includes a bent section (212); The bending section (212) is disposed between the second piece (22) and the avoidance section (211) and / or between the third piece (23) and the avoidance section (211).

2. The filter according to claim 1, characterized in that, The bottom wall of the first resonant cavity (11) is provided with a first protrusion (14), and the second plate (22) is grounded through the first protrusion (14).

3. The filter according to claim 2, characterized in that, The height of the first protrusion (14) is denoted as H1, and the distance between the first protrusion (14) and the resonator (10) in the first resonant cavity (11) along its own width direction is denoted as L1. Among them, the size of H1 is negatively correlated with the coupling effect of the coupling plate (2); The absolute value of the difference between H1 and L1 is negatively correlated with the coupling effect of the coupling plate (2).

4. The filter according to claim 1, characterized in that, The bottom wall of the third resonant cavity (13) is provided with a second protrusion (15), and the third plate (23) is grounded through the second protrusion (15).

5. The filter according to claim 4, characterized in that, The height of the second protrusion (15) is denoted as H2, and the distance between the second protrusion (15) and the resonator (10) in the third resonant cavity (13) along its own width direction is denoted as L2. Among them, the size of H2 is positively correlated with the coupling effect of the coupling plate (2); The absolute value of the difference between H2 and L2 is negatively correlated with the coupling effect of the coupling plate (2).

6. The filter according to claim 1, characterized in that, The third piece (23) is grounded to the resonator (10) inside the third resonant cavity (13).

7. The filter according to claim 1, characterized in that, The distance between the bent section (212) and the resonator (10) in the corresponding resonant cavity (1) is negatively correlated with the coupling amount between two adjacent resonant cavities (1).

8. The filter according to any one of claims 1 to 7, characterized in that, The grounding terminals of the second piece (22) and the third piece (23) are also provided with annular washers.

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