Dielectric filter

Abstract

The utility model relates to a dielectric filter. The dielectric filter comprises a filter body which is provided with at least three resonant cavities, and two non-adjacent resonant cavities are a first resonant cavity and a second resonant cavity; the first metal coating is attached to the filter body; the coupling structure comprises a first coupling hole formed in the side wall of the filter body, and the first coupling hole corresponds to the first resonant cavity; the second coupling hole is formed in the side wall of the filter body, and the second coupling hole corresponds to the second resonant cavity; the second metal coating covers the first coupling hole and the second coupling hole and extends from the first coupling hole to the second coupling hole; wherein an isolation area is arranged between the second metal coating and the first metal coating. According to the dielectric filter, the first coupling hole and the second coupling hole are electrically connected through the second metal coating, the assembly difficulty is reduced, the isolation area is arranged between the second metal coating and the first metal coating through etching, the preparation precision is high, and the consistency of batch production can be improved.

Description

Technical Field

[0001] The present application relates to the field of filtering equipment, and in particular to a dielectric filter. Background Art

[0002] Filters are categorized as metal cavity filters and dielectric filters. To meet satellite miniaturization requirements, filter miniaturization is essential. However, the miniaturization of metal cavity filters can introduce the risk of vacuum microdischarge. Dielectric filters are more easily miniaturized and lightweight. However, the coupling structure of existing dielectric filters uses metal rods connecting PCB microstrip boards to electrically connect different resonant units. The assembly and soldering of the metal rods and PCB boards can easily introduce significant errors, impacting the performance of the dielectric filter. Utility Model Content

[0003] Based on the above problems, the present application provides a dielectric filter to reduce the difficulty of assembly and improve the performance of the dielectric filter.

[0004] One embodiment of the present application provides a dielectric filter, comprising:

[0005] The filter body is provided with at least three resonant cavities, wherein two non-adjacent resonant cavities are a first resonant cavity and a second resonant cavity;

[0006] a first metal plating layer attached to the filter body;

[0007] Coupling structure, including:

[0008] a first coupling hole, disposed on a side wall of the filter body, the first coupling hole corresponding to the first resonant cavity;

[0009] a second coupling hole, disposed on a side wall of the filter body, the second coupling hole corresponding to the second resonant cavity;

[0010] a second metal plating layer, covering the first coupling hole and the second coupling hole, and extending from the first coupling hole to the second coupling hole;

[0011] Wherein, an isolation region is provided between the second metal plating layer and the first metal plating layer.

[0012] According to some embodiments of the present application, the coupling structure further includes a coupling slot, which is arranged on the side wall of the filter body, and the first coupling hole, the second coupling hole, the second metal plating layer and the isolation area are all arranged at the bottom of the coupling slot.

[0013] According to some embodiments of the present application, the dielectric filter further includes a cover plate, which closes the coupling slot.

[0014] According to some embodiments of the present application, both the first coupling hole and the second coupling hole are through holes.

[0015] According to some embodiments of the present application, both the first coupling hole and the second coupling hole are blind holes.

[0016] According to some embodiments of the present application, the apertures of the first coupling hole and the second coupling hole are both 1 to 4 mm.

[0017] According to some embodiments of the present application, the dielectric filter further includes an electrical connector, which is disposed at an end of the filter body.

[0018] According to some embodiments of the present application, the first metal plating layer and the second metal plating layer are attached to the filter body through the same electroplating, and the isolation region is etched between the first metal plating layer and the second metal plating layer.

[0019] According to some embodiments of the present application, two opposite side walls at the top of the filter body are provided with filter grooves.

[0020] According to some embodiments of the present application, the ratio of the length of the filter slot to the length of the filter body is 1:1.2-2, and the ratio of the height of the filter slot to the height of the filter body is 1:1.5-3.

[0021] The dielectric filter of the present application realizes the electrical connection between the first coupling hole and the second coupling hole through the second metal plating layer, avoids the use of metal rods and PCB boards, reduces the difficulty of assembly, and sets an isolation area between the second metal plating layer and the first metal plating layer by etching, with high preparation precision, which is conducive to improving the consistency of mass production. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solution of the present application, the following is a brief introduction to the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without exceeding the scope of protection required by this application.

[0023] Figure 1 Schematic diagram of a dielectric filter according to an embodiment of the present application;

[0024] Figure 2 is a schematic diagram of the first metal coating in an embodiment of the present application;

[0025] Figure 3 Schematic diagram of the internal structure of the filter body according to the embodiment of the present application;

[0026] Figure 4is a schematic diagram of a filter body according to an embodiment of the present application;

[0027] Figure 5 is a schematic diagram of the coupling structure of an embodiment of the present application;

[0028] Figure 6 is a schematic diagram of the second metal coating in an embodiment of the present application;

[0029] Figure 7 Schematic diagram of the cover plate of the embodiment of the present application. DETAILED DESCRIPTION

[0030] The following is a clear and complete description of the technical solution of this application in conjunction with the drawings in the embodiments of this application. Obviously, the embodiments described are part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without making any creative efforts are within the scope of protection of this application.

[0031] like Figure 1 and Figure 2 As shown, an embodiment of the present application provides a dielectric filter 100, which includes a filter body 1, a first metal plating layer 2, and a coupling structure 3. The dielectric filter 100 is easy to assemble, which is conducive to improving the performance of the dielectric filter.

[0032] like Figure 3 As shown, the filter body 1 is made of a dielectric material, for example, ceramic. The filter body 1 is sequentially provided with at least three resonant cavities 11, which extend upward from the bottom surface of the filter body 1. The two non-adjacent resonant cavities are a first resonant cavity 11a and a second resonant cavity 11b. Optionally, the filter body 1 is substantially a rectangular parallelepiped.

[0033] A first metal coating 2 is attached to the surface of the filter body 1, covering the filter body 1. The first metal coating 2 does not cover the coupling structure 3. Alternatively, silver can be electroplated onto the surface of the filter body 1. The resonant cavity 11 is attached to the first metal coating 2 to form a resonant unit. The first metal coating 2 has a uniform thickness of approximately 0.01 mm.

[0034] The dielectric filter 100 is filled with a dielectric material. In operating mode, the generated charged particles are difficult to penetrate, making it difficult to form secondary electrons, resulting in a high power threshold. The dielectric material exhibits minimal deformation at high and low temperatures, is stable, and exhibits excellent high and low temperature performance and consistency.

[0035] like Figure 4 and Figure 5The coupling structure 3 includes a first coupling hole 31, a second coupling hole 32, and a second metal coating 33. The first coupling hole 31 and the second coupling hole 32 are both located on the same sidewall of the filter body 1. The first coupling hole 31 corresponds to the first resonant cavity 11a and extends from the sidewall of the filter body 1 to the first resonant cavity 11a. The second coupling hole 32 corresponds to the second resonant cavity 11b and extends from the sidewall of the filter body 1 to the second resonant cavity 11b.

[0036] The second metal coating 33 covers the first coupling hole 31 and the second coupling hole 32. The second metal coating 33 has a uniform thickness. For example, if the first coupling hole 31 and the second coupling hole 32 are both through holes, the second metal coating 33 covers the hole walls of the first coupling hole 31 and the second coupling hole 32. The second metal coating 33 is a continuous metal coating, extending from the first coupling hole 31 to the second coupling hole 32, to achieve electrical connection between the first coupling hole 31 and the second coupling hole 32, thereby enabling cross-coupling between non-adjacent resonant units. Optionally, the second metal coating 33 is formed by a silver plating process. The thickness of the second metal coating 33 is approximately 0.01 mm.

[0037] An isolation region 4 is provided between the second metal plating layer 33 and the first metal plating layer 2 . The isolation region 4 has no metal plating layer, so as to achieve insulation between the second metal plating layer 33 and the first metal plating layer 2 .

[0038] The dielectric filter 100 of this embodiment does not use metal rods and PCB boards, and requires almost no assembly, reducing assembly difficulty. The dimensions of the second metal plating layer 33 and the isolation region 4 are easy to control, and the manufacturing precision is high, which is conducive to improving product consistency during mass production.

[0039] In some embodiments, the coupling structure 3 further includes a coupling slot 34 disposed on the sidewall of the filter body 1. The first coupling hole 31, the second coupling hole 32, the second metal coating 33, and the isolation region 4 are all disposed at the bottom of the coupling slot 34, thereby protecting the second metal coating 33. The first metal coating 2 at least covers the walls of the coupling slot 34. The depth of the coupling slot 34 is 1 to 3 mm, for example, 2 mm. The depth of the coupling slot 34 affects the depth of the first coupling hole 31 and the second coupling hole 32. The greater the depth of the coupling slot 34, the greater the degree of coupling.

[0040] like Figure 6As shown, the second metal coating 33 includes a first cylindrical portion 331, a second cylindrical portion 332, a first annular portion 333, a second annular portion 334, and a strip portion 335. Both the first cylindrical portion 331 and the second cylindrical portion 332 are hollow structures. The first cylindrical portion 331 is attached to the wall of the first coupling hole 31, and the second cylindrical portion 332 is attached to the wall of the second coupling hole 32. The first annular portion 333 and the second annular portion 334 are both attached to the bottom of the coupling groove 34. The first annular portion 333 is coaxially disposed and connected to the first cylindrical portion 331, and the second annular portion 334 is coaxially disposed and connected to the second cylindrical portion 332. The strip portion 335 is attached to the bottom of the coupling groove 34 and extends from the first annular portion 333 to the second annular portion 334. The shapes of the isolation region 4 and the coupling groove 34 are compatible with the second metal coating 33.

[0041] Optionally, the width D1 of the strip portion 335 is 0.3-2 mm, for example, the width D1 of the strip portion 335 is 1 mm. The larger the width D1 of the strip portion 335 is, the greater the coupling degree is.

[0042] like Figure 7 As shown, in some embodiments, the dielectric filter 100 further includes a cover plate 5 made of metal that seals the opening of the coupling slot 34. For example, the cover plate 5 is a rectangular parallelepiped, with dimensions slightly larger than the opening of the coupling slot 34. The cover plate 5 is welded to the first metal coating 2 on the sidewall of the filter body 1 to seal the opening of the coupling slot 34. The cover plate 5 protects the coupling structure 3 and prevents electromagnetic leakage, thereby avoiding the generation of other interference signals.

[0043] In some embodiments, both the first coupling hole 31 and the second coupling hole 32 are through holes. The first cylindrical portion 331 of the second metal coating 33 extends to connect with the first metal coating on the inner wall of the first resonant cavity 11a, and the second cylindrical portion 3321 extends to connect with the first metal coating on the inner wall of the second resonant cavity 11b, thereby achieving inductive cross-coupling between the two non-adjacent resonant units.

[0044] In some embodiments, the first coupling hole 31 and the second coupling hole 32 are both blind holes. The second metal plating layer 33 covers the bottom of the first coupling hole 31 and the bottom of the second coupling hole 32, and two non-adjacent resonant units achieve capacitive cross coupling.

[0045] In some embodiments, the first coupling hole 31 and the second coupling hole 32 both have a diameter of 1 to 4 mm. For example, the first coupling hole 31 and the second coupling hole 32 both have a diameter of 1.5 mm. The first coupling hole 31 and the second coupling hole 32 have the same diameter. If the diameters of the first coupling hole 31 and the second coupling hole 32 are too large, the machining effort will increase. If the diameters of the first coupling hole 31 and the second coupling hole 32 are too small, machining will be difficult.

[0046] like Figure 7 As shown, in some embodiments, the dielectric filter 100 further includes an electrical connector 6, which can be an existing electrical connector. The electrical connector 6 is disposed at the end of the filter body 1. For example, two electrical connectors 6 are disposed at both ends of the filter body 1.

[0047] In some embodiments, the first metal coating layer 2 and the second metal coating layer 33 are formed by the same electroplating process, and the specific process includes:

[0048] The filter body 1 is processed, and a coupling groove 34, a first coupling hole 31 and a second coupling hole 32 are processed on the side wall of the filter body 1;

[0049] Silver-plating the entire filter body 1 to form a metal plating layer on the filter body 1;

[0050] An isolation region 4 is etched on the metal plating layer to form a first metal plating layer 2 and a second metal plating layer 33 that are insulated from each other.

[0051] The first metal plating layer 2 and the second metal plating layer 33 are formed by electroplating in one step, which simplifies the preparation process of the dielectric filter 100. The etching process has high precision, which is beneficial to improving the dimensional accuracy of the second metal plating layer 33 and the isolation area 4 and reducing the workload of later debugging the coupling degree.

[0052] In some embodiments, two opposite side walls at the top of the filter body 1 are each provided with a filter slot 7. The filter slot 7 can adjust the frequency of the second harmonic generated by the filter to a region with a large difference from the working passband of the filter.

[0053] For example, if the filter's operating passband is 1 GHz to 1.2 GHz and the filter slot 7 is not provided, the frequency of the second harmonic generated by the filter is 2.0 to 2.1 GHz. After the filter slot 7 is provided, the frequency of the second harmonic generated by the filter is 2.6 to 2.8 GHz.

[0054] In some embodiments, the ratio of the length L1 of the filter slot 7 to the length L2 of the filter body 1 is 1:1.2~2, and the ratio of the height H1 of the filter slot 7 to the height H2 of the filter body 1 is 1:1.5~3. For example, the length L1 of the filter slot 7 is 50 mm, and the length L2 of the filter body 1 is 75 mm. The height H1 of the filter slot 7 is 6 mm, and the height H2 of the filter body 1 is 12 mm. The depth of the filter slot 7 is set according to requirements, for example, the depth of the filter slot 7 is 2 mm. The dielectric filter 100 of this embodiment is easy to miniaturize to meet the requirements of satellite miniaturization. The dielectric filter 100 has fewer parts, high consistency in mass production, and improved production yield.

[0055] The embodiments of the present application are described in detail above. Specific examples are used herein to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only intended to help understand the technical solutions and core concepts of the present application. Therefore, changes or modifications made by those skilled in the art based on the concepts of the present application, the specific implementation methods, and the scope of application of the present application, all fall within the scope of protection of the present application. In summary, the contents of this specification should not be construed as limiting the present application.

Claims

1. A dielectric filter, characterized in that: include: The filter body is provided with at least three resonant cavities, wherein two non-adjacent resonant cavities are a first resonant cavity and a second resonant cavity; a first metal plating layer attached to the filter body; Coupling structure, including: a first coupling hole, disposed on a side wall of the filter body, the first coupling hole corresponding to the first resonant cavity; a second coupling hole, disposed on a side wall of the filter body, the second coupling hole corresponding to the second resonant cavity; a second metal plating layer, covering the first coupling hole and the second coupling hole, and extending from the first coupling hole to the second coupling hole; Wherein, an isolation region is provided between the second metal plating layer and the first metal plating layer.

2. The dielectric filter according to claim 1, wherein The coupling structure further includes a coupling slot, which is arranged on a side wall of the filter body. The first coupling hole, the second coupling hole, the second metal plating layer and the isolation region are all arranged on a bottom of the coupling slot.

3. The dielectric filter according to claim 2, wherein A cover plate is also included, which closes the coupling slot.

4. The dielectric filter according to claim 1, wherein The first coupling hole and the second coupling hole are both through holes.

5. The dielectric filter according to claim 1, wherein The first coupling hole and the second coupling hole are both blind holes.

6. The dielectric filter according to claim 1, wherein The apertures of the first coupling hole and the second coupling hole are both 1-4 mm.

7. The dielectric filter according to claim 1, wherein An electrical connector is also included, and the electrical connector is arranged at the end of the filter body.

8. The dielectric filter according to claim 1, wherein The first metal plating layer and the second metal plating layer are attached to the filter body through the same electroplating, and the isolation region is etched between the first metal plating layer and the second metal plating layer.

9. The dielectric filter according to claim 1, wherein Two opposite side walls of the top of the filter body are both provided with filter grooves.

10. The dielectric filter according to claim 9, wherein The ratio of the length of the filter slot to the length of the filter body is 1:1.2-2, and the ratio of the height of the filter slot to the height of the filter body is 1:1.5-3.

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