CN111162353A

CN111162353A - Dielectric filter and communication device

Info

Publication number: CN111162353A
Application number: CN202010043593.5A
Authority: CN
Inventors: 吴亚晖; 吴文敬; 李�杰; 袁昕
Original assignee: Shenzhen Tatfook Technology Co Ltd
Current assignee: Shenzhen Tatfook Technology Co Ltd
Priority date: 2020-01-15
Filing date: 2020-01-15
Publication date: 2020-05-15

Abstract

The invention provides a dielectric filter and a communication device, which comprise at least three dielectric resonators connected with each other, wherein each dielectric resonator comprises a body made of solid dielectric materials and a tuning hole positioned on the surface of the body, and the bodies of all the dielectric resonators form the body of the dielectric filter; at least a set of negative coupling hole, arbitrary group's negative coupling hole includes two at least negative coupling holes, and two negative coupling holes set up respectively on two relative surfaces of dielectric filter body, and all are located two dielectric resonator's hookup location department, and arbitrary negative coupling hole is the blind hole, and dielectric filter's body surface, tuning hole surface and negative coupling hole surface cover the conducting layer. Set up the negative coupling hole respectively on two relative surfaces of dielectric filter body, and the negative coupling hole can set up different degree of depth and adjust the coupling volume, and the adjustable medium that can avoid negative coupling hole bottom to opposite simultaneously is too thin, appears surperficial arch or swell when adding man-hour.

Description

Dielectric filter and communication device

Technical Field

The invention relates to the technical field of communication, in particular to a dielectric filter and a communication device.

Background

5G communication is the leading communication technology at present, and various communication companies compete to develop research on relevant aspects. The Sub 6GHz adopts MIMO technology, so a large number of filters are required to be integrated inside the antenna, and thus higher requirements are imposed on the size and weight of the filters. The traditional metal filter cannot be integrated with an antenna due to too large volume and weight.

The miniaturized dielectric filter realized by adopting the high dielectric constant material is an effective solution for realizing a Sub 6GHz MIMO communication system at present because the size and the weight of the miniaturized dielectric filter are lower than 1/100 of the traditional filter. The dielectric filter adopts a body made of solid dielectric materials (such as ceramic materials with high dielectric constant), and the surface of the body is metalized (such as silver plating) to form a dielectric resonator; the dielectric filter is formed by a plurality of dielectric resonators connected in series and coupling between the respective resonators (including direct coupling between adjacent dielectric resonators and cross coupling between non-adjacent dielectric resonators). The coupling between the resonators can be divided into positive coupling (also referred to as inductive coupling) and negative coupling (also referred to as capacitive coupling) according to polarity. The dielectric filter is easier to realize cross coupling with positive polarity, but is more difficult to realize cross coupling with negative polarity.

In order to realize the negative cross coupling of the dielectric filter, in the prior art, a deep blind hole is processed between two dielectric resonators, which is equivalent to loading a large capacitor to realize the negative cross coupling, but the blind hole forming the negative cross coupling is deep, and the dielectric layer from the bottom of the blind hole to the opposite side is very thin; in addition, the mechanical strength of the dielectric filter body is affected, and the service life of the dielectric filter body is reduced.

Disclosure of Invention

Therefore, the technical problem to be solved by the invention is to overcome the defects of high processing precision of the dielectric filter, influence on flatness and low mechanical strength in the prior art.

To this end, the present invention provides a dielectric filter, comprising:

at least three connected dielectric resonators, each dielectric resonator comprising a body of solid dielectric material and a tuning hole in the surface of the body; the bodies of all the dielectric resonators form the body of the dielectric filter;

at least one set of negative coupling holes; any set of the negative coupling holes comprises at least two negative coupling holes; the two negative coupling holes are respectively arranged on two opposite surfaces of the dielectric filter body and are both positioned at the connecting position of the two dielectric resonators;

any negative coupling hole is a blind hole;

and the surface of the body of the dielectric filter, the surface of the tuning hole and the surface of the negative coupling hole are covered with conductive layers.

Any group of the negative coupling holes comprises two negative coupling holes; the two negative coupling holes are coaxially arranged.

The negative coupling holes in any one of the sets of negative coupling holes may be provided at different depths.

The depth of at least one negative coupling hole in any group of negative coupling holes is greater than or equal to one half of the thickness of the dielectric filter body.

The depth of the negative coupling hole and the area of the conducting layer covered in the negative coupling hole are related to the coupling amount of capacitive coupling between the two dielectric resonators connected at the position of the negative coupling hole.

The depth of the tuning hole and the area of the conducting layer covered in the tuning hole are both related to the resonant frequency of the dielectric resonator where the tuning hole is located.

The thickness of the conductive layer is greater than or equal to the skin depth.

The conducting layer is a silver layer.

The solid dielectric material is a ceramic material.

All dielectric resonator bodies are integrally formed by the same solid dielectric material.

The invention provides a communication device comprising at least one dielectric filter as described above.

The technical scheme of the invention has the following advantages:

1. the invention provides a dielectric filter, which comprises at least three dielectric resonators connected with each other, wherein each dielectric resonator comprises a body made of solid dielectric materials and a tuning hole positioned on the surface of the body, and the bodies of all the dielectric resonators form the body of the dielectric filter; at least a set of negative coupling hole, arbitrary group's negative coupling hole includes two at least negative coupling holes, and two negative coupling holes set up respectively on two relative surfaces of dielectric filter body, and all are located two dielectric resonator's hookup location department, and arbitrary negative coupling hole is the blind hole, and dielectric filter's body surface, tuning hole surface and negative coupling hole surface cover the conducting layer. Set up the negative coupling hole respectively on two relative surfaces of dielectric filter body, and the negative coupling hole can set up different degree of depth and adjust the coupling volume, can avoid negative coupling hole bottom too thin to opposite medium simultaneously, appear surperficial arch or swell when processing man-hour.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and other drawings can be obtained by those skilled in the art without creative efforts.

FIG. 1 is a schematic diagram of a dielectric filter according to the present invention;

FIG. 2 is a schematic structural view of a ceramic body of the present invention located on one side of a tuning hole;

fig. 3 is a frequency response curve of a dielectric filter according to the present invention.

Description of reference numerals:

1-a ceramic body; 11-a silver layer; 2-input-output port; 3-a tuning hole; 4-PCB; 40-abdicating holes; 5-green oil; 6-negative coupling hole.

Detailed Description

The technical solutions of the present invention will be described clearly and completely with reference to the accompanying drawings, and it should be understood that the described embodiments are some, but not all embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

In addition, the technical features involved in the different embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

Example 1

The embodiment provides a dielectric filter, which comprises at least three connected dielectric resonators, wherein each dielectric resonator comprises a body made of solid dielectric material and a tuning hole 3 positioned on the surface of the body, and the bodies of all the dielectric resonators form the body of the dielectric filter. In the present embodiment, as shown in fig. 1, four dielectric resonators are provided, as shown in fig. 2, each dielectric resonator has one tuning hole 3, the four dielectric resonators are arranged in a matrix, and five, six, and so on dielectric resonators may be provided. In this embodiment, the solid dielectric material is a ceramic material, and the body of the dielectric resonator is the ceramic body 1, but other materials, such as glass, may be adopted as required. In this embodiment, all dielectric resonator bodies are integrally formed by using the same ceramic body 1, as shown in fig. 2, that is, four tuning holes 3 are distributed on the same ceramic body 1 in a shape like a Chinese character 'tian'.

The surface of the ceramic body 1 is covered with a conductive layer, the conductive layer can be a copper layer, a tin layer, a silver layer 11 or an aluminum layer and other metal layers, and the thickness of the conductive layer is larger than or equal to the skin depth. In this embodiment, the conductive layer is a silver layer 11, and covers the surface of the ceramic body 1, thereby realizing a complete and closed electromagnetic field transmission structure. The tuning hole 3 is covered with a silver layer 11, and the depth of the tuning hole 3 and the area of the silver layer 11 covered in the tuning hole 3 are related to the resonant frequency of the dielectric resonator in which the tuning hole 3 is positioned. Fig. 3 is a frequency response curve of the dielectric filter in the present embodiment.

At least a set of negative coupling hole 6, any set of negative coupling hole 6 includes at least two negative coupling holes 6, two negative coupling holes 6 are respectively arranged on two opposite surfaces of the dielectric filter body, and are all located at the connecting position of two dielectric resonators, in this embodiment, a set of negative coupling hole 6 is arranged, two negative coupling holes 6 are included in a set of negative coupling holes 6, each negative coupling hole 6 is a blind hole, a silver layer 11 covers the blind hole, as shown in fig. 1, a reverse negative coupling hole 6 is arranged on the surface of the ceramic body 1 where the input and output port 2 is located, as shown in fig. 2, a positive negative coupling hole 6 is arranged on the surface of the ceramic body 1 where the tuning hole 3 is located and between two tuning holes 3. Of course, two or three sets of negative coupling holes 6 may be provided, and each set may include three or four negative coupling holes 6, as required.

Each negative coupling hole 6 can be set to different depths, which is beneficial to reducing the processing precision and the processing difficulty, and preferably, the depth of at least one negative coupling hole 6 in one group of negative coupling holes 6 is more than or equal to one half of the thickness of the dielectric filter body. In this embodiment, the two negative coupling holes 6 on the front and back surfaces are coaxially arranged, so that when any negative coupling hole 6 is processed, even if the bottom of the negative coupling hole bulges or protrudes towards the opposite surface, the flatness of the surface of the whole dielectric filter is not affected. The negative coupling holes 6 arranged on the two opposite sides in the same group can also be arranged in a staggered mode, namely, are not coaxial, and the sum of the depths of the two negative coupling holes 6 can be larger than the thickness of the ceramic body 1.

The depth of the negative coupling hole 6 and the area of the silver layer 11 covered in the negative coupling hole 6 are related to the coupling amount of the capacitive coupling between the two dielectric resonators connected at the position of the negative coupling hole 6.

In this embodiment, a PCB4 cover plate is further provided, the PCB4 is provided with an abdicating hole 40 corresponding to the input/output port 2, and the PCB4 is soldered on the surface of the ceramic body 1 by solder.

As a first alternative embodiment of embodiment 1, the PCB4 cover may not be provided.

Example 2

The present embodiment provides a communication device including at least one dielectric filter of embodiment 1.

It should be understood that the above examples are only for clarity of illustration and are not intended to limit the embodiments. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. And obvious variations or modifications therefrom are within the scope of the invention.

Claims

1. A dielectric filter, comprising:

at least three connected dielectric resonators, each dielectric resonator comprising a body of solid dielectric material and a tuning hole (3) in a surface of the body; the bodies of all the dielectric resonators form the body of the dielectric filter;

at least one set of negative coupling holes (6); any group of the negative coupling holes (6) comprises at least two negative coupling holes (6); the two negative coupling holes (6) are respectively arranged on two opposite surfaces of the dielectric filter body and are positioned at the connecting positions of the two dielectric resonators;

any negative coupling hole (6) is a blind hole;

and the surface of the body of the dielectric filter, the surface of the tuning hole (3) and the surface of the negative coupling hole (6) are covered with a conductive layer.

2. A dielectric filter as claimed in claim 1, characterized in that any one set of said negative coupling holes (6) comprises two negative coupling holes (6); the two negative coupling holes (6) are coaxially arranged.

3. A dielectric filter as claimed in claim 1, characterized in that the negative coupling holes (6) in any one of the sets of negative coupling holes (6) can be provided with different depths.

4. A dielectric filter according to claim 3, characterized in that the depth of at least one of the negative coupling holes (6) in any set of the negative coupling holes (6) is greater than or equal to half the thickness of the dielectric filter body.

5. A dielectric filter according to claim 3, wherein the depth of the negative coupling hole (6) and the area of the conductive layer covered in the negative coupling hole (6) are related to the amount of capacitive coupling between two dielectric resonators adjacent to each other at the location of the negative coupling hole (6).

6. A dielectric filter as claimed in claim 1, characterized in that the depth of the tuning hole (3) and the area of the conductive layer covered in the tuning hole (3) are both related to the resonance frequency of the dielectric resonator in which the tuning hole (3) is located.

7. The dielectric filter of claim 1, wherein the thickness of the conductive layer is greater than or equal to a skin depth.

8. A dielectric filter according to any of claims 1-7, characterized in that the electrically conductive layer is a silver layer (11).

9. A dielectric filter as claimed in any one of claims 1 to 7, wherein the solid dielectric material is a ceramic material.

10. A dielectric filter as claimed in claim 9, wherein all of the dielectric resonator bodies are integrally formed of the same solid dielectric material.

11. A communication device comprising at least one dielectric filter according to any one of claims 1 to 10.