A filter with high efficiency in trial production and suitable for mass production

Abstract

The filter provided by the present invention comprises at least two resonators, two interpenetrating negative coupling grooves, and a conductive layer. A debugging block is arranged on the inner wall of a first negative coupling groove so that the projection of the lower surface of the debugging block on the lower surface of the filter completely covers the projection of the second negative coupling groove on the lower surface of the filter body, so that a connecting cavity extending in a horizontal direction is formed between the lower surface of the debugging block and the groove bottom of the first negative coupling groove, and capacitive coupling between the two resonators is realized through the first negative coupling groove, the second negative coupling groove, and the connecting cavity. The filter body with good consistency can be firstly mass-produced, and then debugging blocks of different sizes can be manufactured to change the size of the connecting cavity, thereby adjusting the electrical performance of the filter. The debugging block itself has no slots or holes, and has small errors, high precision, and strong reproducibility during sintering. The filter has high efficiency and low cost during trial production and is suitable for mass production.

Description

[0001] Divisional Application Statement

[0002] This application is a divisional application of the Chinese invention patent application with the invention name “A filter and its manufacturing method” and application number 202010870390.3 filed on August 26, 2020. Technical Field

[0003] The present application relates to the field of electronic communication equipment, and in particular to a filter which has high efficiency during trial production and is suitable for mass production. Background Art

[0004] With the advent of the "big bang" era of 5G communications, electronic communication equipment is gradually becoming popular around the world, and filters are an important part of electronic communication equipment, determining key factors such as the radiation range and signal strength of electronic base stations.

[0005] Traditional filters have defects such as large size, high loss, and low dielectric constant, which cannot meet the needs of 5G communications. As a result, waveguide filters came into being. At the same resonant frequency, the dielectric constant of the material is higher and the size is smaller. With the continuous improvement of base station performance, the performance requirements for filters are also getting higher and higher. Traditional waveguide filters mostly use inductive coupling, which is difficult to meet specific electrical performance requirements such as suppression of the near end of the filter frequency band. To solve this problem, filters using capacitive coupling have appeared on the market. For example, international patent application WO 2018148905 A1 discloses a filter that realizes capacitive coupling between resonant cavities by setting through holes and conductive isolation layers on the block. However, this solution requires the additional setting of a conductive isolation layer, which is complicated in process, requires the use of additional equipment, and is costly. For example, Chinese invention patent

[0006] CN111403872A discloses a dielectric filter that can achieve capacitive coupling without setting a conductive isolation layer. However, this solution is achieved by adjusting the size of the first negative coupling groove and / or the second negative coupling groove, the distance between the first negative coupling groove and the first debugging hole, and the diameter and length of the negative coupling hole when matching different electrical properties. A whole filter needs to be produced for a single trial production, which is inefficient and costly. Moreover, after adjusting the size of the negative coupling groove or the negative coupling hole, a certain error will be generated during sintering, resulting in poor reproducibility during trial production, which is particularly inconvenient in mass production. Summary of the invention

[0007] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a filter which has high efficiency during trial production and is suitable for mass production.

[0008] To achieve the above object, the technical solution adopted by the present invention is a filter with high efficiency during trial production and suitable for mass production, comprising:

[0009] at least two resonators, each of the resonators comprising a resonator body, all of the resonator bodies forming a filter body, and the filter body extending in a horizontal direction;

[0010] A coupling slot, wherein the coupling slot is a blind slot, and the coupling slot comprises a first negative coupling slot opened on the upper surface of the filter body and extending downward, and a second negative coupling slot opened on the lower surface of the filter body and extending upward;

[0011] a conductive layer covering the surface of the filter body, the inner wall surface of the first negative coupling slot, and the inner wall surface of the second negative coupling slot;

[0012] The first negative coupling slot is connected to the second negative coupling slot, a debugging block is arranged on the inner wall of the first negative coupling slot, the projection of the lower surface of the debugging block on the lower surface of the filter body completely covers the projection of the second negative coupling slot on the lower surface of the filter body, a connecting cavity extending in the horizontal direction is formed between the lower surface of the debugging block and the bottom of the first negative coupling slot, the outer wall surface of the debugging block is covered with the conductive layer, and the joint surface of the debugging block and the first negative coupling slot is not covered with the conductive layer, at least one of the first negative coupling slot, the second negative coupling slot and the connecting cavity is located at the connecting position of the two resonators and connects the two resonators, and the first negative coupling slot, the second negative coupling slot and the connecting cavity are used to realize capacitive coupling between the two resonators.

[0013] Preferably, the upper surface of the debugging block is located in an opening area of ​​the first negative coupling slot on the upper surface of the filter body.

[0014] Preferably, an adhesive layer is provided on the joint surface between the debugging block and the first negative coupling slot, and the adhesive layer is used to fix the debugging block on the inner wall of the first negative coupling slot.

[0015] Further preferably, the adhesive layer is formed by sintering an adhesive to strengthen the fixing effect of the debugging block on the inner wall of the first negative coupling slot and prevent the conductive layer from entering.

[0016] Further preferably, the debugging block is a cuboid, three side surfaces of the debugging block are connected to the inner wall of the first negative coupling slot through the adhesive layer, and the remaining side surface of the debugging block is not in contact with the inner wall of the first negative coupling slot.

[0017] Preferably, a center line of the first negative coupling slot and a center line of the second negative coupling slot are parallel.

[0018] Preferably, the resonator body is made of ceramic material, and the material of the debugging block is the same as that of the resonator body.

[0019] Preferably, the resonator further comprises a debugging hole located on the upper surface of the resonator body, the inner wall surface of the debugging hole is covered with the conductive layer, and the debugging hole is a blind hole for debugging the resonant frequency of the resonator in which the debugging hole is located.

[0020] Preferably, the conductive layer is made of silver.

[0021] Further preferably, the filter body and the debugging block are formed by sintering a green embryo formed by dry pressing of ceramic powder, and the conductive layer of the filter body and the debugging block is formed by a silver immersion or silver spraying process. Before forming the conductive layer, the debugging block is bonded to the first negative coupling slot by an adhesive and sintered into shape.

[0022] Due to the application of the above technical solution, the present invention has the following advantages compared with the prior art:

[0023] The filter provided by the present invention comprises at least two resonators, a first negative coupling slot, a second negative coupling slot and a conductive layer. The two negative coupling slots are interconnected and a debugging block is arranged on the inner wall of the first negative coupling slot so that the projection of the lower surface of the debugging block on the lower surface of the filter completely covers the projection of the second negative coupling slot on the lower surface of the filter body, so that a connecting cavity extending in a horizontal direction is formed between the lower surface of the debugging block and the bottom of the first negative coupling slot, and the capacitive coupling between the two resonators is realized through the first negative coupling slot, the second negative coupling slot and the connecting cavity. The filter body with good consistency can be firstly mass-produced, and then debugging blocks of different sizes can be manufactured to change the size of the connecting cavity, thereby adjusting the electrical performance of the filter. The debugging block itself has no slots or holes, and has small error, high precision and strong reproducibility during sintering. The filter has high efficiency and low cost during trial production and is suitable for mass production. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0025] Figure 1 It is a three-dimensional schematic diagram of a preferred embodiment of the present invention.

[0026] Figure 2 yes Figure 1 Schematic top view of .

[0027] Figure 3 yes Figure 2 Schematic cross-sectional view along the AA direction.

[0028] Figure 4 yes Figure 3 A partial enlarged view of point B in the middle.

[0029] Figure 5 yes Figure 2 The cross-sectional view in the AA direction only shows the filter body and the debugging hole.

[0030] Figure 6 It is a process flow chart of the manufacturing method of the present invention.

[0031] Among them: 10. filter; 101. filter body; 20. first resonator; 201. first resonator body; 202. first debugging hole; 30. second resonator; 301. second resonator body; 302. second debugging hole; 41. first negative coupling slot; 42. second negative coupling slot; 43. debugging block; 431. connecting cavity; 50. adhesive layer; 60. conductive layer. DETAILED DESCRIPTION

[0032] The following will describe the technical solutions in the embodiments of the present invention in detail in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0033] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like indicate directions or positional relationships based on the attached Figure 1 The orientation or positional relationship shown is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0034] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0035] like Figure 1-5 As shown, the filter 10 provided by the present invention includes a first resonator 20 and a second resonator 30. The first resonator 20 includes a first resonator body 201 made of a ceramic material and a first debugging hole 202 located on the upper surface of the first resonator body 201. The first debugging hole 202 is a blind hole, and the first debugging hole 202 is used to debug the resonant frequency of the first resonator 20; the second resonator 30 includes a second resonator body 301 made of a ceramic material and a second debugging hole 302 located on the upper surface of the second resonator body 301. The second debugging hole 302 is a blind hole, and the second debugging hole 302 is used to debug the resonant frequency of the second resonator 30; the first resonator body 201 and the second resonator body 301 together constitute a filter body 101 of the filter 10, and the filter body 101 extends in the horizontal direction; the filter 10 also includes a first resonator body 201 made of a ceramic material and a second debugging hole 302 located on the upper surface of the second resonator body 301. The second debugging hole 302 is a blind hole, and the second debugging hole 302 is used to debug the resonant frequency of the second resonator 30. A negative coupling slot 41, a second negative coupling slot 42 and a conductive layer 60, wherein the first negative coupling slot 41 is opened on the upper surface of the filter body 101 and extends downward, and the first negative coupling slot 41 is a blind slot; the second negative coupling slot 42 is opened on the lower surface of the filter body 101 and extends upward, and the second negative coupling slot 42 is a blind slot, and the second negative coupling slot 42 is connected with the first negative coupling slot 41; the conductive layer 60 is made of silver, and the conductive layer 60 covers the surface of the filter body 101 of the filter 10, the inner wall surface of the first debugging hole 202 and the second debugging hole 302, and the inner wall surface of the second negative coupling slot 42; the axis lines of the first debugging hole 202 and the second debugging hole 302 are parallel, and the center line of the first negative coupling slot 41 and the center line of the second negative coupling slot 42 are parallel to the axis lines of the first debugging hole 202 and the second debugging hole 302.

[0036] like Figure 2-4As shown, a debugging block 43 is also arranged on the inner wall of the first negative coupling slot 41, the upper surface of the debugging block 43 is located in the opening area of ​​the first negative coupling slot 41 on the upper surface of the filter body 101, the projection of the lower surface of the debugging block 43 on the lower surface of the filter body 101 completely covers the projection of the second negative coupling slot 42 on the lower surface of the filter body 101, and a connecting cavity 431 extending in the horizontal direction is formed between the lower surface of the debugging block 43 and the bottom of the first negative coupling slot 41; the conductive layer 60 also covers the inner wall surface of the first negative coupling slot 41 and the debugging block 43. The outer wall surface, but the joint surface of the first negative coupling groove 41 and the debugging block 43 is not covered with the conductive layer 60; at least one of the first negative coupling groove 41, the second negative coupling groove 42, and the connecting cavity 431 is located at the connecting position of the first resonator 20 and the second resonator 30. In the present embodiment, the first negative coupling groove 41 and the connecting cavity 431 are located at the connecting position and connect the first resonator 20 and the second resonator 30. The first negative coupling groove 41, the second negative coupling groove 42, and the connecting cavity 431 work together to realize the capacitive coupling between the first resonator 20 and the second resonator 30.

[0037] In this embodiment, the material of the debugging block 43 is the same as that of the first resonator body 201 and the second resonator body 301, both of which are ceramic materials, such as Figure 3-4 As shown, an adhesive layer 50 is provided on the joint surface between the debugging block 43 and the first negative coupling groove 41. The adhesive layer 50 is formed by sintering an adhesive. The adhesive is used to bond the debugging block 43 to the inner wall of the first negative coupling groove 41. The adhesive layer 50 sintered by the adhesive can further strengthen the fixing effect of fixing the debugging block 43 to the inner wall of the first negative coupling groove 41. In addition, since the adhesive layer 50 is filled into the joint portion between the debugging block 43 and the first negative coupling groove 41, it is difficult for the conductive layer 60 to enter, and thus it cannot cover the joint surface between the debugging block 43 and the first negative coupling groove 41.

[0038] like Figure 1-4 As shown, the opening of the first negative coupling slot 41 on the upper surface of the filter body 101 is rectangular, the opening of the second negative coupling slot 42 on the lower surface of the filter body 101 is also rectangular, and the debugging block 43 is a cuboid. The debugging block 43 is embedded in the first negative coupling slot 41. The embedding means that the three side surfaces of the debugging block 43 are connected to the inner wall of the first negative coupling slot 41 through the adhesive layer 50, and the remaining side surface of the debugging block 43 is not in contact with the inner wall of the first negative coupling slot 41.

[0039] The filter provided by the present invention realizes the capacitive coupling between the first resonator 20 and the second resonator 30 through the joint action of the first negative coupling slot 41, the second negative coupling slot 42, and the connecting cavity 431. The filter body 101 with good consistency can be mass-produced first, and then the debugging blocks 43 of different sizes are manufactured to change the size of the connecting cavity 431, thereby changing the electrical performance of the filter 10 to match different electrical performance requirements. The debugging block 43 itself has no slots or holes, and the error during sintering is small, the precision is high, and the reproducibility is strong. The filter has high efficiency and low cost during trial production, and is suitable for mass production.

[0040] The present invention also provides a method for manufacturing the filter, the process flow of which is as follows: Figure 6 As shown, the specific steps include:

[0041] a. The ceramic powder is dry pressed to form a green embryo of the filter body 101 having a first negative coupling slot 41, a second negative coupling slot 42 and a first debugging hole 202 and a second debugging hole 302; the ceramic powder is dry pressed to form a green embryo of the debugging block 43;

[0042] b. The green embryo of the filter body 101 and the green embryo of the debugging block 43 are sintered into ceramic to form the filter body 101 and the debugging block 43;

[0043] c. The debugging block 43 is bonded to the first negative coupling slot 41 by an adhesive, sintered and formed, so that the adhesive is cured into an adhesive layer 50 to form a semi-finished filter 10;

[0044] d. The semi-finished product is subjected to silver immersion or silver spraying treatment to form a conductive layer 60 on the semi-finished product. Due to the presence of the adhesive layer 50, it is difficult to process the bonding surface of the debugging block 43 and the first negative coupling slot 41 during silver immersion or silver spraying, so that the conductive layer 60 cannot cover the bonding surface of the debugging block 43 and the first negative coupling slot 41, thereby obtaining the filter 10.

[0045] The manufacturing method has simple processing technology, high yield rate and is suitable for mass production.

[0046] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0047] The above is only a specific implementation of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present application. These improvements and modifications should also be regarded as the scope of protection of the present application.

Claims

1. A filter having high efficiency during trial production and suitable for mass production, comprising: at least two resonators, each of the resonators comprising a resonator body, all of the resonator bodies forming a filter body, and the filter body extending in a horizontal direction; A coupling slot, wherein the coupling slot is a blind slot, and the coupling slot comprises a first negative coupling slot opened on the upper surface of the filter body and extending downward, and a second negative coupling slot opened on the lower surface of the filter body and extending upward; a conductive layer covering the surface of the filter body, the inner wall surface of the first negative coupling slot, and the inner wall surface of the second negative coupling slot; Features: The first negative coupling slot is connected to the second negative coupling slot, a debugging block is arranged on the inner wall of the first negative coupling slot, the projection of the lower surface of the debugging block on the lower surface of the filter body completely covers the projection of the second negative coupling slot on the lower surface of the filter body, a connecting cavity extending in the horizontal direction is formed between the lower surface of the debugging block and the bottom of the first negative coupling slot, the outer wall surface of the debugging block is covered with the conductive layer, and the joint surface of the debugging block and the first negative coupling slot is not covered with the conductive layer, at least one of the first negative coupling slot, the second negative coupling slot and the connecting cavity is located at the connecting position of the two resonators and connects the two resonators, and the first negative coupling slot, the second negative coupling slot and the connecting cavity are used to realize capacitive coupling between the two resonators.

2. The filter according to claim 1, which has high efficiency during trial production and is suitable for mass production, is characterized in that: The upper surface of the debugging block is located in an opening area of ​​the first negative coupling slot on the upper surface of the filter body.

3. The filter according to claim 1, which has high efficiency during trial production and is suitable for mass production, is characterized in that: An adhesive layer is provided on the joint surface between the debugging block and the first negative coupling slot, and the adhesive layer is used to fix the debugging block on the inner wall of the first negative coupling slot.

4. The filter according to claim 3, which has high efficiency during trial production and is suitable for mass production, is characterized in that: The adhesive layer is formed by sintering an adhesive to strengthen the fixing effect of the debugging block on the inner wall of the first negative coupling slot and prevent the conductive layer from entering.

5. The filter according to claim 3, which has high efficiency during trial production and is suitable for mass production, is characterized in that: The debugging block is a cuboid, three side surfaces of the debugging block are connected to the inner wall of the first negative coupling slot through the adhesive layer, and the remaining side surface of the debugging block is not in contact with the inner wall of the first negative coupling slot.

6. The filter according to claim 1, which has high efficiency during trial production and is suitable for mass production, is characterized in that: The center line of the first negative coupling slot and the center line of the second negative coupling slot are parallel.

7. The filter according to claim 1, which has high efficiency during trial production and is suitable for mass production, is characterized in that: The resonator body is made of ceramic material, and the material of the debugging block is the same as that of the resonator body.

8. The filter according to claim 1, which has high efficiency during trial production and is suitable for mass production, is characterized in that: The resonator further comprises a debugging hole located on the upper surface of the resonator body, the inner wall surface of the debugging hole is covered with the conductive layer, and the debugging hole is a blind hole, which is used for debugging the resonant frequency of the resonator in which the debugging hole is located.

9. The filter according to claim 1, which has high efficiency during trial production and is suitable for mass production, is characterized in that: The conductive layer is made of silver.

10. The filter according to claim 9, which has high efficiency during trial production and is suitable for mass production, is characterized in that: The filter body and the debugging block are formed by sintering a green embryo formed by dry pressing of ceramic powder. The conductive layer of the filter body and the debugging block is formed by a silver immersion or silver spraying process. Before forming the conductive layer, the debugging block is bonded to the first negative coupling slot by an adhesive and sintered.

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