Filter and filter assembly with same

Abstract

The invention provides a filter and a filter assembly with the same. Wherein the filter comprises a rectangular dielectric block, the rectangular dielectric block has a TE102 resonant mode, a TE201 resonant mode, a TE202 resonant mode and a TEd0d resonant mode, and a degenerate mode is arranged between the TE102 resonant mode and the TE201 resonant mode; at least part of the tuning structure is arranged in the rectangular dielectric block, and the tuning structure is used for carrying out disturbance coupling on a TE102 resonant mode, a TE201 resonant mode, a TE202 resonant mode and a TEd0d resonant mode; and at least part of the excitation structures are arranged in the rectangular dielectric block, the number of the excitation structures is at least two, at least one excitation structure is an input end, and at least the other excitation structure is an output end. The multi-mode filter effectively solves the problem that a multi-mode filter in the prior art is large in size.

Description

Technical Field

[0001] The present invention relates to the technical field of filters, and in particular to a filter and a filter component having the same. Background Art

[0002] At present, filters have been widely used in electronic equipment such as aviation, aerospace, radar, communication, and electronic countermeasures, and have good frequency selection and filtering functions. In the prior art, there are many theoretical design methods for filters, including classic models such as Butterworth filter, elliptic function filter, and Chebyshev filter. The coupling matrix method proposed by AEAtia and AEA Williams in the 1970s [1]-[5] is based on the resonant circuit and the coupling characteristics between the resonant modes. The coupling matrix of the filter is synthesized, and then the physical structure design is carried out. The coupling matrix method has been widely used in engineering, and the typical example is the cavity filter.

[0003] However, traditional multi-mode filters usually achieve filtering functions by coupling multiple coaxial resonant cavities, that is, a multi-cavity multi-mode structure. This structure is large in size and is not suitable for various electronic devices that are gradually being miniaturized. Summary of the invention

[0004] The main purpose of the present invention is to provide a filter and a filter assembly having the same, so as to solve the problem of large volume of multi-mode filters in the prior art.

[0005] In order to achieve the above-mentioned purpose, according to one aspect of the present invention, a filter is provided, the filter comprising: a rectangular dielectric block, having a TE102 resonance mode, a TE201 resonance mode, a TE202 resonance mode and a TEd0d resonance mode, wherein the TE102 resonance mode and the TE201 resonance mode are degenerate modes; a tuning structure, at least part of which is arranged in the rectangular dielectric block, and the tuning structure is used for performing disturbance coupling between the TE102 resonance mode, the TE201 resonance mode, the TE202 resonance mode and the TEd0d resonance mode; an excitation structure, at least part of which is arranged in the rectangular dielectric block, and there are at least two excitation structures, at least one excitation structure is an input end, and at least another excitation structure is an output end.

[0006] Furthermore, the filter also includes: a rectangular housing having a rectangular cavity, wherein the rectangular cavity is filled with a medium to form a rectangular dielectric block.

[0007] Further, at least a portion of the rectangular housing is made of metal material.

[0008] Furthermore, at least a portion of the tuning structure coincides with a geometric center of the rectangular dielectric block.

[0009] Further, at least a portion of the tuning structure is made of a metal material.

[0010] Furthermore, the tuning structure is arranged in a cylindrical or prismatic shape, the excitation structure is a probe, and the central axis of the tuning structure and the central axis of the excitation structure are arranged parallel to each other; or, the central axis of the tuning structure and the central axis of the excitation structure are arranged at an angle.

[0011] Furthermore, there are two excitation structures, which are respectively located on two sides of the tuning structure.

[0012] Furthermore, the rectangular dielectric block has a receiving through hole, and the receiving through hole is used to receive the excitation structure.

[0013] Furthermore, the rectangular shell has a penetration hole, which is communicated with the accommodating through hole and is used for the excitation structure to penetrate.

[0014] According to another aspect of the present invention, a filter assembly is provided, the filter assembly comprising at least two filters and an excitation member, wherein in two adjacent filters, an accommodating through hole of one filter is coaxially arranged with an accommodating through hole of the other filter to form a connecting through hole, the excitation member is penetrated in the connecting through hole, and the part of the excitation member located in the accommodating through hole forms an excitation structure of the filter corresponding to the accommodating through hole, and in the filters located at both ends, the excitation structures of the two filters located outside the connecting through holes respectively form input ends and output ends; wherein the filter is the above-mentioned filter.

[0015] By applying the technical solution of the present invention, the rectangular dielectric block of the filter has TE 102 Resonance mode, TE 201 Resonance mode, TE 202 Resonance mode and TE d0d Resonance mode, TE 102 Resonance Mode and TE 201 The resonant modes are degenerate modes, and at least part of the tuning structure is arranged in the rectangular dielectric block to adjust the TE 102 Resonance mode, TE 201 Resonance mode, TE 202 Resonance mode and TE d0d The resonant modes are disturbed and coupled, at least part of the excitation structure is arranged in the rectangular dielectric block, there are at least two excitation structures, at least one excitation structure is an input end, and at least another excitation structure is an output end. In this way, the filter in the present application is actually a single-cavity four-mode filter. Through the design of the rectangular dielectric block and the special selection of the resonant mode (i.e., TE 102 Resonance mode, TE 201Resonance mode, TE 202 Resonance mode and TE d0d Resonance mode, TE 102 Resonance Mode and TE 201 The resonant modes are degenerate modes), so that a single tuning structure can perturb the coupling of four resonant modes. Compared with the multi-cavity multi-mode filter in the prior art, the filter structure in this application is simpler and smaller in size, thereby solving the problem of large size of the multi-mode filter in the prior art. d0d Higher-order modes are beneficial to broadening the passband bandwidth, making the filter have better filtering performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The drawings constituting a part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0017] Figure 1 A schematic diagram of the three-dimensional structure of an embodiment of a filter according to the present invention is shown;

[0018] Figure 2 Shows Figure 1 A schematic diagram of the internal structure of the filter in FIG.

[0019] Figure 3 Shows Figure 1 A schematic diagram of the internal structure of the filter from a side view;

[0020] Figure 4 Shows Figure 1 The TE of the filter in 102 Internal magnetic field distribution diagram of the resonant mode;

[0021] Figure 5 Shows Figure 1 The TE of the filter in 201 Internal magnetic field distribution diagram of the resonant mode;

[0022] Figure 6 Shows Figure 1 The TE of the filter in 202 Internal magnetic field distribution diagram of the resonant mode;

[0023] Figure 7 Shows Figure 1 The TE of the filter in d0d Internal magnetic field distribution diagram of the resonant mode;

[0024] Figure 8 Shows Figure 1 The TE of the filter in 102 Front view of the internal electric field distribution of the resonant mode;

[0025] Fig. 9 Shows Figure 1 The TE of the filter in 102 Side view of the internal electric field distribution of the resonant mode;

[0026] Fig.10 Shows Figure 1 The TE of the filter in 201 Resonance Mode and TE 202 The coupling relationship between the relative coupling bandwidth between the resonant modes and the radius R of the tuning structure;

[0027] Fig.11 Shows Figure 1 The TE of the filter in 201 Resonance Mode and TE d0d The coupling relationship between the relative coupling bandwidth between the resonant modes and the radius R of the tuning structure;

[0028] Fig.12 Shows Figure 1 The TE of the filter in 202 Resonance Mode and TE d0d The coupling relationship between the relative coupling bandwidth between the resonant modes and the radius R of the tuning structure;

[0029] Fig.13 Shows Figure 1 The filter S parameter frequency response curve of the filter in;

[0030] Fig.14 A schematic diagram showing the internal structure of a filter assembly according to an embodiment of the present invention when there are two filters;

[0031] Fig.15 Shows Fig.13 A schematic diagram of the internal structure when there are three filters in the filter assembly;

[0032] Fig.16 Shows Fig.13 Cascade filter S-parameter frequency response plot of the filter components in FIG.

[0033] The above drawings include the following reference numerals:

[0034] 10. Tuning structure; 20. Excitation structure; 30. Rectangular housing; 31. Accommodating through hole; 40. Excitation member; 51. TE 102 Internal magnetic field distribution diagram of the resonant mode; 52, TE 201 Internal magnetic field distribution diagram of the resonant mode; 53, TE 202 Internal magnetic field distribution diagram of the resonant mode; 54, TE d0dInternal magnetic field distribution diagram of the resonant mode; 55, TE 102 Front view of the internal electric field distribution of the resonant mode; 56, TE 102 Side view of the internal electric field distribution of the resonant mode; 57. Coupling relationship diagram between the relative coupling bandwidth between the TE201 resonant mode and the TE202 resonant mode and the radius R of the tuning structure; 58. Coupling relationship diagram between the relative coupling bandwidth between the TE201 resonant mode and the TEd0d resonant mode and the radius R of the tuning structure; 59. Coupling relationship diagram between the relative coupling bandwidth between the TE202 resonant mode and the TEd0d resonant mode and the radius R of the tuning structure; 60. Frequency response curve of the filter S parameters; 61. Frequency response curve of the cascaded filter S parameters. DETAILED DESCRIPTION

[0035] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0036] It should be noted that, unless otherwise specified, all technical and scientific terms used in this application have the same meanings as commonly understood by ordinary technicians in the technical field to which this application belongs.

[0037] In the present invention, unless otherwise specified, the directional words used, such as "up" and "down", usually refer to the directions shown in the drawings, or to the vertical, perpendicular or gravity directions; similarly, for ease of understanding and description, "left" and "right" usually refer to the left and right shown in the drawings; "inside" and "outside" refer to the inside and outside relative to the outline of each component itself, but the above directional words are not used to limit the present invention.

[0038] In order to solve the problem of large volume of multi-mode filters in the prior art, the present application provides a filter and a filter assembly having the same.

[0039] like Figures 1 to 13 As shown, the filter includes a rectangular dielectric block, a tuning structure 10 and an excitation structure 20. The rectangular dielectric block has a TE 102 Resonance mode, TE 201 Resonance mode, TE 202 Resonance mode and TE d0d Resonance mode, TE 102 Resonance Mode and TE 201 The resonant modes are degenerate modes. At least part of the tuning structure 10 is disposed in the rectangular dielectric block. The tuning structure 10 is used to adjust the TE 102 Resonance mode, TE 201 Resonance mode, TE 202 Resonance mode and TE d0dDisturbance coupling is performed between the resonant modes; at least part of the excitation structure 20 is arranged in the rectangular dielectric block, there are at least two excitation structures 20, at least one excitation structure 20 is an input end, and at least another excitation structure 20 is an output end.

[0040] By applying the technical solution of this embodiment, the rectangular dielectric block of the filter has TE 102 Resonance mode, TE 201 Resonance mode, TE 202 Resonance mode and TE d0d Resonance mode, TE 102 Resonance Mode and TE 201 The resonant modes are degenerate modes, and at least part of the tuning structure 10 is arranged in the rectangular dielectric block to adjust the TE 102 Resonance mode, TE 201 Resonance mode, TE 202 Resonance mode and TE d0d The resonant modes are disturbed and coupled, at least part of the excitation structure 20 is arranged in the rectangular dielectric block, there are at least two excitation structures 20, at least one excitation structure 20 is an input end, and at least another excitation structure 20 is an output end. In this way, the filter in this embodiment is actually a single-cavity four-mode filter. By designing the rectangular dielectric block and specially selecting the resonant mode (i.e., TE 102 Resonance mode, TE 201 Resonance mode, TE 202 Resonance mode and TE d0d Resonance mode, TE 102 Resonance Mode and TE 201 The resonant modes are degenerate modes), so that a single tuning structure 10 can perform disturbance coupling on the four resonant modes. Compared with the multi-cavity multi-mode filter in the prior art, the filter structure in this embodiment is simpler and smaller in size, thereby solving the problem of large size of the multi-mode filter in the prior art. d0d Higher-order modes are beneficial to broadening the passband bandwidth, making the filter have better filtering performance.

[0041] Specifically, the single-cavity quad-mode filter in this embodiment also has the advantages of high Q value, low insertion loss, and large bandwidth.

[0042] like Figures 1 to 3 As shown, the filter further includes a rectangular housing 30 having a rectangular cavity filled with a dielectric to form a rectangular dielectric block.

[0043] Optionally, the medium filled in the rectangular cavity may be air or other medium.

[0044] Optionally, at least a portion of the rectangular housing 30 is made of a metal material.

[0045] In this embodiment, the rectangular housing 30 is entirely made of metal material.

[0046] Optionally, at least part of the tuning structure 10 coincides with the geometric center of the rectangular dielectric block. Thus, the above arrangement ensures that the tuning structure 10 has high disturbance and coupling reliability while making the setting position of the tuning structure 10 more flexible and diverse to adapt to different working conditions and usage requirements.

[0047] In this embodiment, the tuning structure 10 is disposed at the geometric center of the rectangular dielectric block to ensure that the setting position of the tuning structure 10 matches the structure of the rectangular dielectric block, thereby ensuring that the disturbance coupling reliability of the tuning structure 10 is optimal.

[0048] like Figures 4 to 9 As shown, it shows TE 102 Internal magnetic field distribution diagram of resonant mode 51, TE 201 Internal magnetic field distribution diagram of resonant mode 52, TE 202 Internal magnetic field distribution diagram of resonant mode 53, TE d0d Internal magnetic field distribution diagram of resonant mode 54, TE 102 Front view of the internal electric field distribution of the resonant mode 55 and TE 102 Side view of the internal electric field distribution of the resonant mode 56 (TE 201 Resonance mode, TE 202 Resonance mode and TE d0d Electric field distribution diagram of resonant mode and TE 102 The resonance modes are similar and are not described in detail here). It can be seen from the above schematic diagram that the magnetic fields of the four resonance modes selected in this embodiment are all arranged around the geometric center point of the rectangular dielectric block. Therefore, setting the tuning structure 10 at the geometric center of the rectangular dielectric block is beneficial to the simultaneous perturbation of the four tuning modes, so as to realize the synchronous coupling control of the four tuning modes.

[0049] In this embodiment, at least a portion of the tuning structure 10 is made of metal material. Thus, the above configuration ensures that the tuning structure 10 has a higher disturbance coupling performance, so as to improve the reliability of its synchronous coupling control of the four tuning modes.

[0050] In this embodiment, the tuning structure 10 is arranged in a cylindrical or prismatic shape, the excitation structure 20 is a probe, and the central axis of the tuning structure 10 and the central axis of the excitation structure 20 are arranged parallel to each other; or, the central axis of the tuning structure 10 and the central axis of the excitation structure 20 are arranged at an angle. In this way, the above arrangement makes the postures of the tuning structure 10 and the excitation structure 20 match each other (that is, both are perpendicular to the magnetic field of the tuning mode and arranged parallel to each other), so as to further improve the coupling control reliability of the tuning structure 10, thereby improving the filtering performance of the filter. At the same time, the above arrangement also makes the structure of the tuning structure 10 more flexible and diverse, and improves the processing flexibility of the staff.

[0051] In this embodiment, the central axis of the tuning structure 10 and the central axis of the excitation structure 20 are arranged parallel to each other.

[0052] In this embodiment, the tuning structure 10 is cylindrical to ensure that the outer circumference of the tuning structure 10 and the outer circumference of the rectangular dielectric block have a more uniform distance consistency.

[0053] In this embodiment, the tuning structure 10 is arranged along the height direction of the rectangular dielectric block.

[0054] In this embodiment, the radius of the cylindrical tuning structure 10 is R.

[0055] In this embodiment, there are two excitation structures 20, and the two excitation structures 20 are respectively located on both sides of the tuning structure 10. In this way, the position setting of the two excitation structures 20 and the tuning structure 10 makes the overall layout of the filter more symmetrical, that is, it can match the magnetic field distribution states of the four tuning modes, which is conducive to improving the coupling control performance of the tuning structure 10, and further improves the filtering performance of the filter.

[0056] In this embodiment, the two excitation structures 20 are respectively located on two sides of the tuning structure 10 and are symmetrically arranged with respect to the central plane of the rectangular dielectric block.

[0057] like Figures 1 to 3 As shown, the rectangular dielectric block has a receiving through hole 31 located in the rectangular cavity, and the receiving through hole 31 is used to receive the excitation structure 20. In this way, the excitation structure 20 in this embodiment actually adopts a probe method (accommodating through hole 31), thereby making the overall structure of the filter simpler, easier to process and realize.

[0058] In this embodiment, the receiving through hole 31 of the rectangular dielectric block can be adaptively processed according to the forming medium of the rectangular dielectric block. For example, the plastic medium can be formed by a mold, and it is only necessary to ensure that it can form the receiving through hole 31.

[0059] In this embodiment, the accommodating through hole 31 is a cylindrical through hole, and the radius thereof is not limited, that is, the hole wall of the accommodating through hole 31 may be in close contact with the excitation structure 20 , or there may be a gap between the hole wall and the excitation structure 20 .

[0060] In this embodiment, the rectangular housing 30 has a penetration hole, which is connected to the receiving through hole 31 and is used for the excitation structure 20 to penetrate. In this way, the above arrangement provides a corresponding basis for the penetration of the excitation structure 20 to ensure that the excitation structure 20 can be penetrated into the receiving through hole 31.

[0061] like Figures 10 to 13 As shown, it shows TE 201 Resonance Mode and TE 202 The coupling relationship between the relative coupling bandwidth between the resonant modes and the radius R of the tuning structure is shown in Figure 57. TE 201 Resonance Mode and TE d0d The coupling relationship between the relative coupling bandwidth between the resonant modes and the radius R of the tuning structure is shown in Figure 58. TE 202 Resonance Mode and TE d0d FIG59 shows the coupling relationship between the relative coupling bandwidth between the resonant modes and the radius R of the tuning structure, and FIG60 shows the filter S parameter frequency response curve. As can be seen from the above schematic diagrams, in this embodiment, only a single tuning structure 10 is used to perform synchronous perturbation and coupling control on the four resonant modes. That is, the filter in this embodiment has the advantages of small size and simple structure while realizing its basic filtering function, and can be applied to various electronic devices with gradually miniaturized designs.

[0062] like Figures 14 to 16 As shown, this embodiment also provides a filter assembly, the filter assembly includes at least two filters and an excitation member 40, in two adjacent filters, a receiving through hole 31 of one filter is coaxially arranged with a receiving through hole 31 of another filter to form a connecting through hole, the excitation member 40 is penetrated in the connecting through hole, and the part of the excitation member 40 located in the receiving through hole 31 forms an excitation structure 20 of the filter corresponding to the receiving through hole 31, and in the filters located at both ends, the excitation structures 20 of the two filters located outside the connecting through holes respectively form input ends and output ends. Wherein, the filter is the above-mentioned filter.

[0063] In this embodiment, since the overall structure of the filter is very simple (the tuning structure 10 is only a cylindrical structure arranged in a rectangular dielectric block, and a probe-type excitation method is adopted), multiple filters can be cascaded, that is, by connecting the receiving through holes 31 of the two filters to each other and coaxially arranging them (actually, only one filter needs to be placed on another filter and aligned with the receiving through hole 31), the conduction between the two adjacent filters can be achieved through the probe-type excitation component 40, that is, the specific frequency wave filtered by one filter can be introduced into the next-level filter through the excitation component for re-filtering, and the number of filters in the filter assembly can be arbitrarily set according to actual needs, which greatly improves the filtering performance of the filter assembly.

[0064] like Fig.13 and Fig.16 As shown, the filter S parameter frequency response graph 60 and the cascade filter S parameter frequency response graph 61 are respectively shown (the S parameter frequency response graph of the actual dual-cavity four-mode filter in this schematic diagram, that is, the filter component has two filters cascaded). It can be seen from the above schematic diagram that the filter component with two filters cascaded has a larger passband bandwidth and better filtering performance.

[0065] From the above description, it can be seen that the above embodiments of the present invention achieve the following technical effects:

[0066] The rectangular dielectric block of the filter has TE 102 Resonance mode, TE 201 Resonance mode, TE 202 Resonance mode and TE d0d Resonance mode, TE 102 Resonance Mode and TE 201 The resonant modes are degenerate modes, and at least part of the tuning structure is arranged in the rectangular dielectric block to adjust the TE 102 Resonance mode, TE 201 Resonance mode, TE 202 Resonance mode and TE d0d The resonant modes are disturbed and coupled, at least part of the excitation structure is arranged in the rectangular dielectric block, there are at least two excitation structures, at least one excitation structure is an input end, and at least another excitation structure is an output end. In this way, the filter in the present application is actually a single-cavity four-mode filter. Through the design of the rectangular dielectric block and the special selection of the resonant mode (i.e., TE 102 Resonance mode, TE 201 Resonance mode, TE 202 Resonance mode and TE d0d Resonance mode, TE 102 Resonance Mode and TE 201The resonant modes are degenerate modes), so that a single tuning structure can perturb the coupling of four resonant modes. Compared with the multi-cavity multi-mode filter in the prior art, the filter structure in this application is simpler and smaller in size, thereby solving the problem of large size of the multi-mode filter in the prior art. d0d Higher-order modes are beneficial to broadening the passband bandwidth, making the filter have better filtering performance.

[0067] Obviously, the above-described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0068] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0069] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein.

[0070] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A filter, characterized in that: The filter comprises: Rectangular dielectric block with TE 102 Resonance mode, TE 201 Resonance mode, TE 202 Resonance mode and TE d0d resonant mode, the TE 102 resonant mode and the TE 201 There are degenerate modes between the resonant modes; A tuning structure (10), at least part of which is disposed in the rectangular dielectric block, and the tuning structure (10) is used to adjust the TE 102 Resonance mode, the TE 201 Resonance mode, the TE 202 Resonance mode and the TE d0d Perturbation coupling between resonant modes; An excitation structure (20), at least part of which is arranged in the rectangular dielectric block, and there are at least two excitation structures (20), at least one of which is an input end, and at least another of which is an output end.

2. The filter according to claim 1, characterized in that The filter further comprises: The rectangular shell (30) has a rectangular cavity, and the rectangular cavity is filled with a medium to form the rectangular medium block.

3. The filter according to claim 2, characterized in that At least part of the rectangular housing (30) is made of metal material.

4. The filter according to claim 1, characterized in that At least a portion of the tuning structure (10) coincides with the geometric center of the rectangular dielectric block.

5. The filter according to claim 1, characterized in that At least part of the tuning structure (10) is made of metal material.

6. The filter according to any one of claims 1 to 5, characterized in that The tuning structure (10) is arranged in a cylindrical or prism shape, the excitation structure (20) is a probe, and the central axis of the tuning structure (10) and the central axis of the excitation structure (20) are arranged parallel to each other; or, the central axis of the tuning structure (10) and the central axis of the excitation structure (20) are arranged at an angle.

7. The filter according to claim 6, characterized in that There are two excitation structures (20), and the two excitation structures (20) are respectively located on two sides of the tuning structure (10).

8. The filter according to claim 2, characterized in that The rectangular dielectric block has a receiving through hole (31), and the receiving through hole (31) is used to receive the excitation structure (20).

9. The filter according to claim 8, characterized in that The rectangular shell (30) has a penetration hole, which is in communication with the accommodating through hole (31) and is used for the excitation structure (20) to penetrate through.

10. A filter component, characterized in that: The filter assembly comprises at least two filters and an excitation member (40); in two adjacent filters, a receiving through hole (31) of one filter is coaxially arranged with a receiving through hole (31) of the other filter to form a connecting through hole; the excitation member (40) is penetrated in the connecting through hole; the part of the excitation member (40) located in the receiving through hole (31) forms an excitation structure (20) of the filter corresponding to the receiving through hole (31); in the filters located at both ends, the excitation structures (20) of the two filters located outside the connecting through hole respectively form an input end and an output end; wherein the filter is the filter according to any one of claims 1 to 9.

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