A dielectric filter and a communication device

Abstract

The present invention provides a dielectric filter and a communication device, comprising at least three dielectric resonators connected to each other, each dielectric resonator comprising a body made of solid dielectric material and a tuning hole located on the surface of the body; the bodies of all dielectric resonators constitute the body of the dielectric filter, the surface of the body and the surface of the tuning hole of the dielectric filter are covered with a conductive layer, two electrodes are respectively located on the surfaces of two dielectric resonators on one side of an input and output port, a transmission line connects the two electrodes, and is suitable for transmitting electrical signals; the two electrodes and the transmission line are formed on the surface of the dielectric resonator by a conductive layer. By directly forming the electrodes and the transmission line on the surface of the dielectric resonator through the conductive layer, the structure is simple, easy to adjust, and convenient to achieve negative cross coupling.

Description

Technical Field

[0001] The present invention relates to the field of communication technology, and in particular to a dielectric filter and a communication device. Background Art

[0002] 5G communication is the most cutting-edge communication technology at present, and various communication companies are competing to carry out related research. Among them, Sub 6GHz uses MIMO technology, so a large number of filters need to be integrated into the antenna, so there are higher requirements for the volume and weight of the filter. Traditional metal filters cannot be integrated with antennas due to their large size and weight.

[0003] Miniaturized dielectric filters made of high dielectric constant materials are an effective solution for implementing Sub 6GHz MIMO communication systems because their size and weight are less than 1 / 100 of traditional filters. This type of dielectric filter uses a body made of solid dielectric material (such as ceramic material with high dielectric constant) and metallizes the surface of the body (such as silver plating) to form a dielectric resonator; a dielectric filter is formed by connecting multiple dielectric resonators in sequence and coupling between each resonator (including direct coupling between adjacent dielectric resonators and cross-coupling between non-adjacent dielectric resonators). Among them, the coupling between each resonator can be divided into positive coupling (also called inductive coupling) and negative coupling (also called capacitive coupling) according to polarity. It is easier for this type of dielectric filter to achieve cross-coupling with positive polarity, but it is more difficult to achieve cross-coupling with negative polarity.

[0004] In order to achieve negative cross-coupling of dielectric filters, the prior art uses a surface metallized flying rod to connect two dielectric resonators. The existing flying rod material and form are mainly made of metal materials, and are installed inside the cavity with a flying rod seat. This installation by mechanical processing is not only cumbersome, but also cannot be adjusted after installation, and is inconvenient to debug. It is necessary to disassemble the metal cover plate, take out the flying rod, change the length or shape of the flying rod by mechanical processing, and then install it into the cavity for testing, so as to complete a debugging. However, repeated mechanical processing and performance testing operations seriously affect the performance of the filter, and the debugging is complicated and the production efficiency is low. Summary of the invention

[0005] Therefore, the technical problem to be solved by the present invention is to overcome the problems that the dielectric flying rod used in the dielectric filter in the prior art is complicated to process, cannot be adjusted after installation, is complex to debug, and has low production efficiency.

[0006] To this end, the present invention provides a dielectric filter, comprising:

[0007] At least three connected dielectric resonators, each of which comprises a body made of solid dielectric material and a tuning hole located on the surface of the body; the bodies of all the dielectric resonators constitute the body of the dielectric filter; the surface of the body of the dielectric filter and the surface of the tuning hole are covered with a conductive layer; characterized in that:

[0008] Two electrodes, respectively located on the two surfaces of the dielectric resonator at one side of the input and output ports;

[0009] a transmission line, connecting the two electrodes;

[0010] Two electrodes and a transmission line are formed on the surface of the dielectric resonator by the conductive layer.

[0011] The electrode is a blind hole formed on the surface of the solid dielectric material and covering the conductive layer.

[0012] The electrodes are circular, square or triangular.

[0013] Also includes:

[0014] At least one negative coupling window is arranged between the two dielectric resonators.

[0015] The negative coupling window is a groove and / or a hole.

[0016] The depth of the negative coupling window is related to the coupling amount of the negative cross coupling.

[0017] The depth of the tuning hole and the area of ​​the conductive layer covered in the tuning hole are both related to the resonance frequency of the dielectric resonator where the tuning hole is located.

[0018] The thickness of the conductive layer is greater than or equal to the skin depth.

[0019] The conductive layer is a silver layer.

[0020] The solid dielectric material is a ceramic material.

[0021] All dielectric resonator bodies are integrally formed using the same solid dielectric material.

[0022] The present invention provides a communication device, comprising at least one dielectric filter as described above.

[0023] The technical solution of the present invention has the following advantages:

[0024] 1. The dielectric filter provided by the present invention comprises at least three connected dielectric resonators, each of which comprises a body made of solid dielectric material and a tuning hole located on the surface of the body; the bodies of all dielectric resonators constitute the body of the dielectric filter, the surface of the body and the surface of the tuning hole of the dielectric filter are covered with a conductive layer, two electrodes are respectively located on the surfaces of two dielectric resonators on one side of the input and output ports, and a transmission line connects the two electrodes, which is suitable for transmitting electrical signals; the two electrodes and the transmission line are formed on the surface of the dielectric resonator by the conductive layer. The electrodes and the transmission line are directly formed on the surface of the dielectric resonator through the conductive layer, which has a simple structure, is easy to adjust, and is convenient for realizing negative cross coupling. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0026] Figure 1 It is a structural schematic diagram of a dielectric filter of the present invention;

[0027] Figure 2 It is a structural schematic diagram of a tuning hole and a negative coupling window in a dielectric filter of the present invention;

[0028] Figure 3 The figure is a frequency response curve of a dielectric filter of the present invention.

[0029] Description of reference numerals:

[0030] 1-ceramic body; 11-silver layer; 2-electrode; 3-input and output ports; 4-tuning hole; 5-transmission line; 6-PCB; 61-ground copper layer; 62-PCB through hole; 63-give way hole; 7-green oil; 8-negative coupling window. DETAILED DESCRIPTION

[0031] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. 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.

[0032] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0033] 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.

[0034] In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0035] Example 1

[0036] This embodiment provides a dielectric filter, comprising at least three connected dielectric resonators, each of which comprises a body made of solid dielectric material and a tuning hole 4 located on the surface of the body, and the bodies of all dielectric resonators constitute the body of the dielectric filter. Figure 1 As shown, in this embodiment, four dielectric resonators are provided, such as Figure 2 As shown, each dielectric resonator has a tuning hole 4, and four dielectric resonators are arranged in a field shape. Five, six, and so on dielectric resonators can also be provided. In this embodiment, the solid dielectric material is a ceramic material, and the body of the dielectric resonator is a ceramic body 1. Of course, other materials can also be used, depending on specific needs. In this embodiment, all dielectric resonator bodies are integrally formed using the same ceramic body 1, such as Figure 2 As shown, four tuning holes 4 are arranged in a field-shaped distribution on the same ceramic body 1 .

[0037] The surface of the ceramic body 1 is covered with a conductive layer, which may be a metal layer such as a copper layer, a tin layer, a silver layer 11 or an aluminum layer, and the thickness of the conductive layer is greater than or equal to the skin depth. In this embodiment, the conductive layer is a silver layer 11, which covers the surface of the ceramic body 1 to achieve a completely closed electromagnetic field transmission structure. The tuning hole 4 is covered with the silver layer 11, and the depth of the tuning hole 4 and the area of ​​the silver layer 11 covered in the tuning hole 4 are related to the resonant frequency of the dielectric resonator where the tuning hole 4 is located.

[0038] Located on one side surface of the ceramic body 1 opposite to the tuning hole 4, such as Figure 1 As shown, by removing materials, the closed ring-shaped silver layer 11 is partially removed, and the remaining silver layer 11 in the middle forms the electrode 2 and the transmission line 5, and the silver layer 11 is also removed around the two input and output ports 3, and the removed part is coated with green oil 7. Figure 1 As shown, in this embodiment, the electrode 2 and the input / output port 3 are blind holes formed on the surface of the ceramic body 1, and the blind holes are covered with a silver layer 11. Of course, the shape of the electrode 2 can also be a square or a triangle, etc., depending on specific needs.

[0039] In this embodiment, a PCB6 cover is also provided, and the surface of the PCB cover is covered with a copper layer. The copper layer is removed at the positions corresponding to the electrodes 2 and the transmission line 5 on the ceramic body 1, and green oil 7 is applied to the removed portion. Several PCB through holes are evenly provided on the PCB cover around the green oil 7 to play a shielding and grounding role. The copper layer of the remaining part forms a grounding copper layer 61. A clearance hole 63 corresponding to the input and output ports is also provided on the PCB6. The PCB6 is soldered to the surface of the ceramic body 1 by soldering.

[0040] At least one negative coupling window 8 is provided on the side surface where the tuning hole 4 is located. The negative coupling window 8 is provided between two dielectric resonators, that is, between two tuning holes 4. The negative coupling window 8 can be a groove or a hole. The hole can be a blind hole or a through hole. The negative coupling window 8 can also be a combination of a groove and a blind hole or a groove and a through hole, depending on specific needs. The groove or the hole is covered with a silver layer. The size of the negative coupling can be adjusted by removing the silver layer in the groove or the hole. The depth of the negative coupling window 8 is related to the coupling amount of the negative cross coupling. In this embodiment, two negative coupling windows 8 are provided, namely a groove and a blind hole. The groove is provided on the body surface at the connection position of the two dielectric resonators, and the blind hole is provided from the bottom of the groove to the inside of the ceramic body 1. Figure 3 : is the frequency response curve of the dielectric filter in this embodiment.

[0041] The electrodes 2 and the transmission line 5 are directly formed on the surface of the dielectric resonator through a conductive layer, which has a simple structure, is easy to adjust, and facilitates the realization of negative cross coupling.

[0042] Example 2

[0043] This embodiment provides a communication device, comprising at least one dielectric filter in Embodiment 1.

[0044] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the invention.

Claims

1. A dielectric filter, comprising at least three connected dielectric resonators, each dielectric resonator comprising a body made of solid dielectric material and a tuning hole (4) located on the surface of the body; the bodies of all the dielectric resonators constitute the body of the dielectric filter; the surface of the body of the dielectric filter and the surface of the tuning hole (4) are covered with a conductive layer; characterized in that: Two electrodes (2), respectively located on two surfaces of the dielectric resonator on one side of the input and output ports (3); The electrode (2) is a blind hole formed on the surface of the solid dielectric material and covering the conductive layer; A transmission line (5) connecting the two electrodes (2); Two electrodes (2) and a transmission line (5) are formed on the surface of the dielectric resonator by the conductive layer; The conductive layer is a silver layer (11), the silver layer (11) in the closed loop is partially removed, the remaining silver layer (11) in the closed loop forms the electrode (2) and the transmission line (5), and the removed portion in the closed loop is coated with green oil (7).

2. The dielectric filter according to claim 1, characterized in that: The electrode (2) is circular, square or triangular.

3. The dielectric filter according to claim 1, characterized in that Also includes: At least one negative coupling window (8) is arranged between the two dielectric resonators.

4. The dielectric filter according to claim 3, characterized in that The negative coupling window (8) is a groove and / or a hole.

5. The dielectric filter according to claim 4, characterized in that: The depth of the negative coupling window (8) is related to the coupling amount of the negative cross coupling.

6. The dielectric filter according to claim 1, characterized in that The depth of the tuning hole (4) and the area of ​​the conductive layer covered in the tuning hole (4) are both related to the resonance frequency of the dielectric resonator in which the tuning hole (4) is located.

7. The dielectric filter according to claim 1, characterized in that: The thickness of the conductive layer is greater than or equal to the skin depth.

8. The dielectric filter according to claim 1, characterized in that: The solid dielectric material is a ceramic material.

9. The dielectric filter according to claim 8, characterized in that: All dielectric resonator bodies are integrally formed using the same solid dielectric material.

10. A communication device, characterized in that: The method comprises at least one dielectric filter according to any one of claims 1 to 9.

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