A high stability multilayer ceramic dielectric filter

Abstract

The present invention discloses a high-stability laminated ceramic dielectric filter, comprising a first dielectric resonator body and a second dielectric resonator body stacked up and down, wherein a boss is provided on the lower surface of the first dielectric resonator body, a demetallized first annular strip is provided on the boss, and a demetallized second annular strip is provided on the upper surface of the second dielectric resonator body. The present invention reduces the difference in planarity between dielectric resonator bodies by providing a boss on the dielectric resonator body, improves the stability of the coupling bandwidth of the laminated ceramic dielectric filter, reduces the manufacturing difficulty and cost, has a high manufacturing pass rate, and has excellent and stable performance.

Description

Technical Field

[0001] The invention relates to the field of ceramic filters, and in particular to a high-stability laminated ceramic dielectric filter. Background Art

[0002] With the continuous development of communication technology, the miniaturization requirements of base station equipment are getting higher and higher, and the miniaturization of filters is equally important. Traditional metal filters can no longer meet the current miniaturization requirements, especially in 5G communications. With higher requirements for miniaturization, small size, high performance, high power, and low cost filter technology are particularly important for filters in wireless communication applications.

[0003] Ceramic waveguide filters have good performance and the advantages of small size and light weight. However, in the current ceramic waveguide filter industry, there are few ceramic waveguide filter superposition products, mainly due to the difficulty in manufacturing and low yield. The reason for the above problems is that superposition products involve coupling problems in signal transmission. Generally speaking, the larger the spacing between ceramic filters, the smaller the coupling bandwidth of the product and the worse the performance of the product.

[0004] When ceramic products are pressed and sintered, the surface will bend due to the uniform difference in density. The larger the product area, the greater the degree of bending, thereby increasing the spacing between ceramic filters. Therefore, the degree of bending directly affects the strength of signal coupling, making the consistency of product performance worse. Summary of the invention

[0005] In order to overcome the shortcomings of the prior art, the present invention provides a high-stability multilayer ceramic dielectric filter, which can solve the problem of large coupling bandwidth fluctuation caused by large flatness differences in superimposed ceramic filters. The specific technical solution is as follows:

[0006] The present invention provides a high-stability laminated ceramic dielectric filter, comprising a first dielectric resonator body and a second dielectric resonator body stacked up and down, wherein the first dielectric resonator body and the second dielectric resonator body are both made of a ceramic material with a metallized surface;

[0007] The lower surface of the first dielectric resonator body is provided with at least one boss, and the surface of the boss is a metallized structure;

[0008] A demetallized first annular strip is provided on the surface of the boss, and a demetallized second annular strip is provided on the upper surface of the second dielectric resonator body. When the second dielectric resonator body and the second boss are in a fitted state, the first annular strip and the second annular strip are nested to form a coupling window.

[0009] Furthermore, there is a gap region between the first dielectric resonator body and the second dielectric resonator body except for the bonding region between the boss and the second dielectric resonator body, and the gap region is filled with metallized material.

[0010] Further, the number of the first annular strips is plural and they are nested, and / or the number of the second annular strips is plural and they are nested.

[0011] Furthermore, the nesting arrangement of the first annular strip and the second annular strip is as follows: a second annular strip is embedded between two adjacent first annular strips, and / or,

[0012] A first annular strip is embedded between two adjacent second annular strips.

[0013] Furthermore, the first annular strip and the second annular strip are arranged adjacent to each other at equal intervals.

[0014] Furthermore, the number of the first annular strips and the second annular strips are both plural, and the spacing between adjacent first annular strips and second annular strips gradually increases in the direction from the center of the coupling window to the outer edge.

[0015] Furthermore, a central vertical axis of the first annular strip coincides with a central vertical axis of the second annular strip.

[0016] Furthermore, the boss and the first dielectric resonator body are an integrally formed structure.

[0017] Furthermore, the first dielectric resonator body is provided with at least one upper frequency hole for adjusting the resonance frequency, and the second dielectric resonator body is provided with at least one lower frequency hole for adjusting the resonance frequency, and both the upper frequency hole and the lower frequency hole are blind hole structures with metallized inner walls.

[0018] Furthermore, the first dielectric resonator body is provided with a first signal transmission hole with a blind hole structure, and the second dielectric resonator body is provided with a second signal transmission hole with a blind hole structure, and the bottom wall and side wall of the first signal transmission hole and the second signal transmission hole are both covered with a metal layer.

[0019] The beneficial effects brought by the technical solution of the present invention include:

[0020] a. Add a smaller boss at the coupling position of the two ceramic blocks stacked on the surface, thereby reducing the fluctuation range of the flatness, reducing the spacing of the coupling position, and increasing the coupling bandwidth;

[0021] b. Since a small-sized boss can meet the coupling bandwidth requirement, the superposition ceramic filter can be large-sized, reducing the manufacturing difficulty and cost;

[0022] c. The multilayer ceramic dielectric filter has excellent and stable performance and a high manufacturing pass rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0024] Figure 1 1 is a perspective structural diagram of a high-stability multilayer ceramic dielectric filter provided by an embodiment of the present invention;

[0025] Figure 2 is a partial schematic diagram of a high-stability multilayer ceramic dielectric filter provided by an embodiment of the present invention;

[0026] Figure 3 This is the relationship between the coupling bandwidth and spacing of the multilayer ceramic dielectric filter;

[0027] Figure 4 It is the frequency bandwidth state corresponding to the multilayer ceramic dielectric filter when the spacing is 0.1mm;

[0028] Figure 5 It is the frequency bandwidth state corresponding to the multilayer ceramic dielectric filter when the spacing is 0.02mm;

[0029] Figure 6 The following is a table illustrating the performance simulation results of the high-stability multilayer ceramic dielectric filter provided by an embodiment of the present invention.

[0030] Among them, the figure markings are as follows: 1-first dielectric resonator body, 11-boss, 1101-first annular bar, 12-first upper frequency hole, 13-first signal transmission hole, 14-second upper frequency hole, 2-second dielectric resonator body, 21-second annular bar, 22-first lower frequency hole, 23-second signal transmission hole, 24-second lower frequency hole. DETAILED DESCRIPTION

[0031] In order to enable those skilled in the art to better understand the scheme of the present invention, and to more clearly understand the purpose, technical scheme and advantages of the present invention, the technical scheme in the embodiments of the present invention is clearly and completely described below in combination with specific embodiments and with reference to the accompanying drawings. Obviously, the described embodiments are only embodiments of a part of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in the field without creative work should belong to the scope of protection of the present invention. In addition, the terms "including" and "having" in the specification and claims of the present invention and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, device, product or equipment that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or equipment.

[0032] In one embodiment of the present invention, see Figure 1 , provides a high-stability laminated ceramic dielectric filter, comprising a first dielectric resonator body 1 and a second dielectric resonator body 2 stacked up and down, wherein the first dielectric resonator body 1 and the second dielectric resonator body 2 are both made of a ceramic material with a metallized surface;

[0033] At least one boss 11 is disposed on the lower surface of the first dielectric resonator body 1 , and the surface of the boss 11 is a metallized structure.

[0034] In a preferred embodiment of the present invention, the boss 11 and the first dielectric resonator body 1 are an integrally formed structure.

[0035] The ceramic material itself will produce a certain slope of curvature during manufacturing and sintering, but since the area of ​​the boss is small, the change in spacing between the two bosses caused by the change in flatness is also small, thereby weakening the adverse effect of the flatness difference between the upper and lower layers of the multilayer ceramic dielectric filter on the coupling bandwidth stability. Figure 3 The relationship between the coupling bandwidth and the spacing between dielectric resonators is revealed. Figure 4 and Figure 5 The difference between the good performance of the ceramic waveguide filter with a smaller stacking spacing and the poor performance of the ceramic waveguide filter with a larger stacking spacing is more intuitively shown. Therefore, compared with the multilayer ceramic dielectric filter without the boss 11, the multilayer ceramic dielectric filter of the embodiment of the present invention can obtain a more stable coupling bandwidth. The boss can be in any form, and the position and area of ​​the boss are defined according to actual design requirements. The height of the boss is set to be greater than the flatness of the product surface to ensure that the boss can contact the surface of another dielectric resonator.

[0036] In a preferred embodiment of the present invention, there is a gap region between the first dielectric resonator body 1 and the second dielectric resonator body 2 except for the region where the boss 11 and the second dielectric resonator body 2 are attached. Figure 2 As shown, the gap area is filled with metalized material, that is, the gap between the two dielectric resonator bodies is the gap between the boss and the second dielectric resonator body. Since the area of ​​the boss is smaller than the area of ​​the body, the flatness difference between the boss 11 and the upper surface of the second dielectric resonator is much smaller than the surface difference between the two body stacking surfaces without the boss 11, so that the coupling bandwidth between the two dielectric resonator bodies is more stable. Figure 4 and Figure 5 It can be further known from the comparison that the smaller the gap is, the larger the coupling bandwidth is. In summary, the multilayer ceramic dielectric filter that uses the boss to reduce the gap between the two dielectric resonator bodies in the embodiment of the present invention has stronger stability.

[0037] In a preferred embodiment of the present invention, a demetallized first annular strip 1101 is provided on the surface of the boss 11, and a demetallized second annular strip 21 is provided on the upper surface of the second dielectric resonator body 2. When the boss 11 and the second dielectric resonator body 2 are in a fitted state, the first annular strip 1101 and the second annular strip 21 are nested to form a coupling window.

[0038] Specifically, the number of the first annular strips 1101 is plural and they are nested, and / or the number of the second annular strips 21 is plural and they are nested.

[0039] More specifically, the nesting arrangement of the first annular strip 1101 and the second annular strip 21 is as follows: a second annular strip is embedded between two adjacent first annular strips, and / or a first annular strip is embedded between two adjacent second annular strips. For example, taking the arrangement of three first annular strips and three second annular strips as an example (not shown), the first annular strips are numbered 1, 3, and 5 from small to large, and the second annular strips are numbered 2, 4, and 6 from small to large, then the annular strips in the formed coupling window are numbered 1, 2, 3, 4, 5, and 6 from inside to outside.

[0040] The first annular strip 1101 and the second annular strip 21 can be arranged adjacent to each other at equal intervals, or the number of the first annular strip and the second annular strip are both multiple, and the spacing between adjacent first annular strips and second annular strips gradually increases in the direction from the center of the coupling window to the outside.

[0041] In a specific embodiment of the present invention, the central vertical axis of the first annular strip 1101 coincides with the central vertical axis of the second annular strip 21. It should be noted that the shapes of the first annular strip 1101 and the second annular strip 21, such as circular, elliptical or irregular shapes, are determined by actual needs and are not limited in the present invention, as long as it is ensured that two adjacent annular strips in the coupling window 3 do not touch each other.

[0042] The first dielectric resonator body 1 is also provided with at least one upper frequency hole for adjusting the resonance frequency, and the second dielectric resonator body 2 is also provided with at least one lower frequency hole for adjusting the resonance frequency. Both the upper frequency hole and the lower frequency hole are blind hole structures with metallized inner walls.

[0043] The first dielectric resonator body 1 is further provided with a first signal transmission hole 13 with a blind hole structure, and the second dielectric resonator body 2 is further provided with a second signal transmission hole 23 with a blind hole structure. The bottom wall and side wall of the first signal transmission hole 13 and the second signal transmission hole 23 are both covered with a metal layer.

[0044] The present invention does not limit the shape, depth, tilt direction, etc. of the upper frequency hole, the lower frequency hole, the first signal transmission hole, and the second signal transmission hole.

[0045] The present invention does not limit the shapes and sizes of the first dielectric resonator body 1 and the second dielectric resonator body 2 , and the shapes and sizes of the two can be similar or very different.

[0046] The present invention also does not limit the position and number of the bosses; the bosses may be located on the first dielectric resonator body or on the second dielectric resonator body. In fact, by rotating the multilayer ceramic dielectric filter 180° along the horizontal axis, a situation equivalent to "the bosses are located on the second dielectric resonator body" can be obtained, and therefore such a situation also falls within the protection scope of the present invention.

[0047] A specific implementation mode of the present invention is described below by way of example. It should be noted that this is only one of the specific embodiments of the technical solution of the present invention and does not cover all implementation modes of the technical solution of the present invention.

[0048] like Figure 1 The laminated ceramic dielectric filter shown comprises a first dielectric resonator body 1 and a second dielectric resonator body 2 which are stacked up and down, wherein the first dielectric resonator body 1 and the second dielectric resonator body 2 are both made of a ceramic material with a metallized surface;

[0049] The upper surface of the first dielectric resonator body 1 is provided with a first upper frequency hole 12 and a second upper frequency hole 14, both of which are blind hole structures, and the lower surface of the first dielectric resonator body 1 is provided with two blind holes corresponding to the first upper frequency hole 12 and the second upper frequency hole 14 respectively;

[0050] The lower surface of the second dielectric resonator body 2 is provided with a first lower frequency hole 22 and a second lower frequency hole 24, both of which are blind hole structures, and the upper surface of the second dielectric resonator body 2 is provided with two blind holes corresponding to the first lower frequency hole 22 and the second lower frequency hole 24 respectively;

[0051] The upper surface of the first dielectric resonator body 1 is also provided with a first signal transmission hole 13 of a blind hole structure, and the lower surface is provided with a corresponding blind hole;

[0052] The lower surface of the second dielectric resonator body 2 is also provided with a second signal transmission hole 23 of a blind hole structure, and the upper surface is provided with a corresponding blind hole;

[0053] All of the above blind hole structures have been metallized, and the number and position of specific frequency holes and signal transmission holes should not be used as a basis for limiting the protection scope of the present invention.

[0054] like Figure 2 As shown, a boss 11 is provided on the lower surface of the first dielectric resonator body 1, and the surface of the boss 11 is a metallized structure, and the gap between the boss and the second dielectric resonator body 2 is narrower;

[0055] A demetallized first annular strip 1101 is provided on the surface of the boss 11, and a demetallized second annular strip 21 is provided on the upper surface of the second dielectric resonator body 2. The boss 11 and the upper surface of the second dielectric resonator body 2 are in a fitted state, and the first annular strip 1101 and the second annular strip 21 are nested to form a coupling window.

[0056] In this embodiment, the first annular strip 1101 and the second annular strip 21 are circular in shape, the central vertical axis of the first annular strip 1101 coincides with the central vertical axis of the second annular strip 21 , and the first annular strip 1101 is closer to the inside than the second annular strip 21 .

[0057] Figure 6 2 is a performance parameter image of the multilayer ceramic dielectric filter in this embodiment. It can be clearly seen that the multilayer ceramic dielectric filter in this embodiment has excellent performance.

[0058] In summary, for the laminated ceramic waveguide filter, the present invention adds a boss at the coupling position of the two ceramic block stacking surfaces, and the boss height and size can be adjusted according to actual conditions. Since the boss surface area is small, the flatness fluctuation range is small after the ceramic is pressed and sintered, and the consistency is high. Therefore, the laminated ceramic dielectric filter provided by the present invention can improve the coupling bandwidth, while relaxing the restrictions on the size of the ceramic dielectric filter, reducing the manufacturing difficulty and cost; the laminated ceramic dielectric filter has a high manufacturing pass rate, excellent and stable performance, and overcomes the shortcomings of the prior art.

[0059] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A high-stability multilayer ceramic dielectric filter, characterized in that: It comprises a first dielectric resonator body (1) and a second dielectric resonator body (2) which are stacked up and down, wherein the first dielectric resonator body (1) and the second dielectric resonator body (2) are both made of a ceramic material with a metalized surface; The lower surface of the first dielectric resonator body (1) is provided with at least one boss (11), and the surface of the boss (11) is a metallized structure; A demetallized first annular strip (1101) is provided on the surface of the boss (11), and a demetallized second annular strip (21) is provided on the upper surface of the second dielectric resonator body (2); when the boss (11) and the second dielectric resonator body (2) are in a fitted state, the first annular strip (1101) and the second annular strip (21) are nested to form a coupling window.

2. The multilayer ceramic dielectric filter according to claim 1, characterized in that: There is a gap region between the first dielectric resonator body (1) and the second dielectric resonator body (2) except for the bonding region between the boss (11) and the second dielectric resonator body (2), and the gap region is filled with metallized material.

3. The multilayer ceramic dielectric filter according to claim 1, characterized in that: The first annular strips (1101) are multiple and nested, and / or, The second annular strips (21) are multiple in number and are nested.

4. The multilayer ceramic dielectric filter according to claim 3, characterized in that: The nesting arrangement of the first annular strip (1101) and the second annular strip (21) is such that: a second annular strip (21) is embedded between two adjacent first annular strips (1101), and / or, A first annular strip (1101) is embedded between two adjacent second annular strips (21).

5. The high-stability multilayer ceramic dielectric filter according to claim 3, characterized in that: The first annular strip and the second annular strip are arranged adjacent to each other at equal intervals.

6. The high-stability multilayer ceramic dielectric filter according to claim 3, characterized in that: The number of the first annular strip (1101) and the number of the second annular strip (21) are both multiple, and the spacing between adjacent first annular strips (1101) and second annular strips (21) gradually increases in the direction from the center of the coupling window to the outside.

7. The multilayer ceramic dielectric filter according to claim 1, characterized in that: The central vertical axis of the first annular strip (1101) coincides with the central vertical axis of the second annular strip (21).

8. The multilayer ceramic dielectric filter according to claim 1, characterized in that: The boss (11) and the first dielectric resonator body (1) are an integrally formed structure.

9. The multilayer ceramic dielectric filter according to claim 1, characterized in that: The first dielectric resonator body (1) is also provided with at least one upper frequency hole for adjusting the resonance frequency, and the second dielectric resonator body (2) is also provided with at least one lower frequency hole for adjusting the resonance frequency, and both the upper frequency hole and the lower frequency hole are blind hole structures with metallized inner walls.

10. The multilayer ceramic dielectric filter according to claim 1, characterized in that: The first dielectric resonator body (1) is also provided with a first signal transmission hole (13) with a blind hole structure, and the second dielectric resonator body (2) is also provided with a second signal transmission hole (23) with a blind hole structure, and the bottom wall and side wall of the first signal transmission hole (13) and the second signal transmission hole (23) are both covered with a metal layer.

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