CN115425382B

CN115425382B - Three-mode dielectric resonator and dielectric filter

Info

Publication number: CN115425382B
Application number: CN202211041748.7A
Authority: CN
Inventors: 吴亚晖; 钟志波
Original assignee: Anhui Tatfook Technology Co Ltd
Current assignee: Anhui Tatfook Technology Co Ltd
Priority date: 2022-08-29
Filing date: 2022-08-29
Publication date: 2024-05-14
Anticipated expiration: 2042-08-29
Also published as: WO2024046276A1; CN115425382A

Abstract

The application relates to the technical field of communication, and provides a three-mode dielectric resonator and a dielectric filter, wherein a dielectric body of the three-mode dielectric resonator is respectively provided with a first resonance blind hole, a second resonance blind hole and a third resonance blind hole, the first resonance blind hole, the second resonance blind hole and the third resonance blind hole are respectively used for forming a first resonance mode, a second resonance mode and a third resonance mode, and the first resonance mode, the second resonance mode and the third resonance mode are all quasi-TEM modes. The three-mode dielectric resonator provided by the application can effectively improve the space utilization rate of the dielectric resonator, reduce the volume and weight of the dielectric filter and improve the out-of-band rejection performance.

Description

Three-mode dielectric resonator and dielectric filter

Technical Field

The application relates to the technical field of communication, in particular to a three-mode dielectric resonator and a dielectric filter.

Background

The dielectric filter adopts the dielectric body as the resonant cavity, can greatly reduce the volume and weight of the filter, and has the advantages of high Q/V (Q represents quality factor, V represents resonator volume) ratio, high power and the like.

In the creation process of realizing the technical scheme of the application, the inventor finds that the dielectric filter in the related technology mostly adopts a single-mode dielectric resonant cavity or a dual-mode dielectric resonant cavity, the space utilization rate of the dielectric resonant cavity is not high enough, and the current requirement on a small-sized filter is difficult to adapt.

Disclosure of Invention

The application aims to provide a three-mode dielectric resonator and a dielectric filter so as to solve the technical problem that the space utilization rate of a dielectric resonant cavity of the dielectric filter in the related art is not high enough.

In order to achieve the above object, a first aspect of the present application provides a three-mode dielectric resonator, which includes a dielectric body, wherein a first resonant blind hole, a second resonant blind hole and a third resonant blind hole are respectively formed in the dielectric body, the first resonant blind hole, the second resonant blind hole and the third resonant blind hole are respectively used for forming a first resonant mode, a second resonant mode and a third resonant mode, and the first resonant mode, the second resonant mode and the third resonant mode are all quasi-TEM modes.

In one embodiment, the dielectric body has a first plane, a second plane and a third plane, any two of the first plane, the second plane and the third plane are not parallel to each other, the first resonant blind hole is formed in the first plane, the second resonant blind hole is formed in the second plane, and the third resonant blind hole is formed in the third plane.

In one embodiment, the first plane, the second plane and the third plane are perpendicular to each other; and/or the depth direction of the first resonance blind hole, the depth direction of the second resonance blind hole and the depth direction of the third resonance blind hole are perpendicular to each other.

In one embodiment, the dielectric body is provided with a first hybrid coupling structure, and the first hybrid coupling structure is used for performing hybrid coupling between the second resonance mode and the third resonance mode to generate a transmission zero point.

In one embodiment, the first hybrid coupling structure comprises: the two ends of the first magnetic coupling groove are respectively communicated with the second resonance blind hole and the third resonance blind hole and are used for carrying out magnetic coupling between the second resonance mode and the third resonance mode; and a first electrical coupling structure located between the second and third blind resonant holes for providing electrical coupling between the second and third resonant modes.

In one embodiment, the first magnetic coupling groove has a blind groove structure formed on the surface of the dielectric body, and two ends of the first magnetic coupling groove are respectively communicated with the orifice of the second resonance blind hole and the orifice of the third resonance blind hole.

In one embodiment, the first electrical coupling structure is a blind slot structure and the first electrical coupling structure communicates with the third blind resonant hole.

In one embodiment, a depth direction of the first electrical coupling structure is parallel to a depth direction of the third blind resonant hole; the first electric coupling structure is communicated with the first magnetic coupling groove, and the depth of the first electric coupling structure is larger than that of the first magnetic coupling groove; the depth of the first electric coupling structure is greater than or equal to one half of the depth of the third resonance blind hole.

In one embodiment, the first resonant mode, the second resonant mode, and the third resonant mode are coupled to each other two by two, and a cross coupling is formed between the first resonant mode and the third resonant mode to generate a transmission zero.

In one embodiment, the dielectric body is provided with a second electric coupling structure, and the second electric coupling structure is located between the first resonant blind hole and the third resonant blind hole and is used for carrying out electric coupling between the first resonant mode and the third resonant mode so as to form cross coupling.

In one embodiment, the second electrical coupling structure comprises: the first blind groove is formed in the surface of the dielectric body and is positioned between the first resonance blind hole and the third resonance blind hole; the second blind groove is formed in the bottom wall of the first blind groove; wherein the first blind groove and the second blind groove form a stepped blind groove structure; the three-mode dielectric resonator further comprises a first conductive layer and a second conductive layer, wherein the first conductive layer covers the outer surface of the dielectric body, the inner surface of the first resonance blind hole, the inner surface of the second resonance blind hole and the inner surface of the third resonance blind hole; the second conductive layer covers the inner surface of the second blind groove; the inner surface of the first blind groove is exposed so as to electrically insulate the second conductive layer from the first conductive layer.

In one embodiment, the dielectric body is provided with a second magnetic coupling groove, and two ends of the second magnetic coupling groove are respectively communicated with the first resonance blind hole and the second resonance blind hole and are used for carrying out magnetic coupling between the first resonance mode and the second resonance mode; and/or an electric coupling blocking structure is arranged on the dielectric body, and the electric coupling blocking structure is positioned between the first resonance blind hole and the second resonance blind hole and used for blocking electric coupling between the first resonance mode and the second resonance mode.

In one embodiment, the second magnetic coupling groove has a blind groove structure formed on the surface of the dielectric body, and two ends of the second magnetic coupling groove are respectively communicated with the orifice of the first resonance blind hole and the orifice of the second resonance blind hole; and/or the electric coupling blocking structure is a through groove penetrating through two opposite sides of the dielectric body.

In one embodiment, a second hybrid coupling structure is provided on the dielectric body, the second hybrid coupling structure being configured to provide hybrid coupling between the first resonant mode and the second resonant mode to generate a transmission zero.

In one embodiment, the dielectric body is provided with a first hybrid coupling structure, and the first hybrid coupling structure is used for performing hybrid coupling between the second resonance mode and the third resonance mode to generate a transmission zero point; and/or a second hybrid coupling structure is arranged on the dielectric body, and the second hybrid coupling structure is used for performing hybrid coupling between the first resonance mode and the second resonance mode so as to generate a transmission zero point;

The second hybrid coupling structure comprises a coupling blind hole, wherein the coupling blind hole is positioned between the first resonance blind hole and the second resonance blind hole and is used for electrically coupling the first resonance mode and the second resonance mode; the first resonant mode and the second resonant mode are also magnetically coupled.

The dielectric body is provided with a coupling blocking structure, and the coupling blocking structure is positioned between the first resonance blind hole and the third resonance blind hole and used for blocking coupling between the first resonance mode and the third resonance mode.

A second aspect of the present application provides a dielectric filter, the dielectric filter comprising: at least one triple-mode dielectric resonator according to any of the embodiments above; an input coupling hole is arranged on the dielectric body of one of the three-mode dielectric resonators, and is communicated with or capacitively coupled with one of the first resonance blind hole, the second resonance blind hole and the third resonance blind hole on the dielectric body for signal input; the dielectric body of one of the three-mode dielectric resonators is provided with an output coupling hole, and the output coupling hole is communicated with or capacitively coupled with one of the first resonance blind hole, the second resonance blind hole and the third resonance blind hole on the dielectric body and is used for signal output.

In one embodiment, the dielectric filter further comprises a metal film covering the opening of the slot or hole on at least one of the dielectric bodies.

The above-mentioned one or more technical solutions in the embodiments of the present application at least have the following technical effects or advantages:

According to the three-mode dielectric resonator provided by the embodiment of the application, as the dielectric body is respectively provided with the first resonant blind hole, the second resonant blind hole and the third resonant blind hole, the first resonant blind hole is used for forming a first resonant mode, the second resonant blind hole is used for forming a second resonant mode, and the third resonant blind hole is used for forming a third resonant mode, three resonant modes can be realized through a single dielectric body, namely, three resonant modes can be formed in the same dielectric resonant cavity, the space utilization rate of the dielectric resonant cavity can be effectively improved, the space utilization rate of the dielectric resonant cavity is 3 times that of the single-mode dielectric resonant cavity and is 1.5 times that of the dual-mode dielectric resonant cavity, the number of the dielectric resonant cavities can be reduced under the same volume, and the dielectric filter is further miniaturized and light;

meanwhile, as the first resonance mode, the second resonance mode and the third resonance mode are quasi-TEM modes, compared with the TE mode and the TM mode, on one hand, the volume of the dielectric body can be effectively reduced, the space utilization rate of the dielectric resonant cavity is further improved, the volume and the weight of the dielectric filter are further reduced, on the other hand, the second harmonic of the dielectric filter can be farther from the passband, the dielectric filter has more excellent out-of-band rejection performance, and the index performance of the dielectric filter is improved.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are needed in the embodiments or the description of the prior art will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and that other drawings can be obtained according to these drawings without inventive effort for a person skilled in the art.

Fig. 1 is a schematic perspective view of a three-mode dielectric resonator (only a first resonant blind hole, a second resonant blind hole and a third resonant blind hole are provided) according to an embodiment of the present application;

FIG. 2a is a schematic diagram showing an electric field distribution of a first resonant mode of the three-mode dielectric resonator of FIG. 1;

FIG. 2b is a schematic diagram of a magnetic field distribution of a first resonant mode of the three-mode dielectric resonator of FIG. 1;

FIG. 3a is a schematic diagram showing an electric field distribution of a second resonant mode of the three-mode dielectric resonator of FIG. 1;

FIG. 3b is a schematic diagram of a magnetic field distribution of a second resonant mode of the three-mode dielectric resonator of FIG. 1;

FIG. 4a is a schematic diagram showing an electric field distribution of a third resonant mode of the three-mode dielectric resonator of FIG. 1;

FIG. 4b is a schematic diagram of a magnetic field distribution of a third resonant mode of the three-mode dielectric resonator of FIG. 1;

FIG. 5 is a schematic diagram of a dielectric body according to an embodiment of the present application;

FIG. 6 is a schematic diagram of another view of the dielectric body of FIG. 5;

FIG. 7 is a schematic diagram of another view of the dielectric body of FIG. 5;

FIG. 8 is a schematic diagram of another view of the dielectric body of FIG. 5;

FIG. 9 is a schematic diagram of the intermediate body of FIG. 5 in perspective;

FIG. 10 is a schematic perspective view of a dielectric body according to another embodiment of the present application;

FIG. 11 is a schematic structural diagram of a medium assembly according to an embodiment of the present application;

FIG. 12 is a schematic diagram of a medium assembly according to another embodiment of the present application;

fig. 13 is a schematic structural diagram of a dielectric filter according to an embodiment of the present application;

FIG. 14 is a schematic diagram of the topology of the dielectric filter of FIG. 13;

FIG. 15 is a graph of amplitude versus frequency characteristics of the dielectric filter of FIG. 13;

FIG. 16 is a schematic diagram of a dielectric filter according to another embodiment of the present application;

Fig. 17 is a graph of amplitude versus frequency characteristics of the dielectric filter of fig. 16.

Wherein, each reference sign in the figure:

1. A three-mode dielectric resonator; 10. a mediator; 11. a first resonant blind hole; 12. the second resonance blind hole; 13. a third resonant blind hole; 101. a first plane; 102. a second plane; 103. a third plane; 14. a first hybrid coupling structure; 141. a first magnetic coupling slot; 1411. a first trough section; 1412. a second trough section; 1413. a third trough section; 142. a first electrical coupling structure; 151. a second magnetic coupling slot; 1511. a fourth trough section; 1512. a fifth trough section; 1513. a sixth slot section; 152. an electrically coupled blocking structure; 16. a second electrical coupling structure; 161. a first blind slot; 162. a second blind slot; 171. a coupling blind hole; 18. a coupling blocking structure; 191. an input coupling hole; 192. an output coupling hole;

100. A medium assembly; 130. a coupling medium;

200. a dielectric filter; 210. a first conductive layer; 220. and a second conductive layer.

Detailed Description

Embodiments of the present application are described in detail below, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to like or similar elements or elements having like or similar functions throughout. The embodiments described below by referring to the drawings are illustrative and intended to explain the present application and should not be construed as limiting the application.

In the description of the present application, it should be understood that the terms "length," "width," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like indicate orientations or positional relationships based on the orientation or positional relationships shown in the drawings, merely to facilitate describing the present application and simplify the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be configured and operated in a specific orientation, and therefore should not be construed as limiting the present application.

Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more such feature. In the description of the present application, the meaning of "a plurality" is two or more, unless explicitly defined otherwise.

In the present application, unless explicitly specified and limited otherwise, the terms "mounted," "connected," "secured," and the like are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communicated with the inside of two elements or the interaction relationship of the two elements. The specific meaning of the above terms in the present application can be understood by those of ordinary skill in the art according to the specific circumstances.

With the continuous development of wireless communication technology, wireless communication base stations are more and more densely distributed, and the requirements on the size, weight and the like of the base stations are higher and higher. Particularly, in the application of the ultra-large-scale antenna array technology, the requirement of the base station equipment of the 5G communication system on the integration level of the radio frequency device is higher and higher, and the radio frequency front-end filter needs to be miniaturized and light. With the further increase in base station antenna arrays, the system components are continually being upgraded and integrated, and wireless communication systems are in more stringent demand for smaller filters. The dielectric filter has the characteristics of high Q value and small volume, and is the optimal solution of the 5G base station radio frequency filter.

In the creation process of realizing the technical scheme of the application, the inventor finds that the dielectric filter in the related technology mostly adopts a single-mode dielectric resonant cavity or a dual-mode dielectric resonant cavity, namely, the same dielectric resonant cavity only has one or two resonant modes, the space utilization rate of the dielectric resonant cavity is not high enough, and even if the filter adopts a three-mode dielectric resonant cavity, the volume of the dielectric resonant cavity is also increased due to the increase of the number of resonant modes, so that the space utilization rate of the dielectric resonant cavity is still not high, and the dielectric filter is difficult to further miniaturize and lighten, and is difficult to adapt to the current requirement of a miniature filter.

For example, the dual-mode dielectric filter in the related art generally adopts the TE mode (i.e., transverse wave mode, TRANSVERSE ELECTRIC WAVE, TE) and/or TM mode (i.e., transverse magnetic wave mode, TRANSVERSEMAGNETIC WAVE, TM) inherent to the waveguide cavity, so that the thickness of the dielectric cavity is larger, resulting in thicker base station filter and thus thicker profile of the base station antenna feeder, which is in contradiction with the thinning of the profile of the base station antenna feeder; in addition, because the TE mode and the TM mode are waveguide modes, the parasitic secondary resonance frequency is generally 1.2-1.3 times of the fundamental mode frequency, so the far-end inhibition of the filter designed by the multimode resonator is poor, and the base station can generate interference and noise to communication of other frequency bands.

Based on this, the inventors have proposed the following means for solving the technical problem that the space utilization of the dielectric resonator of the dielectric filter in the related art is not high enough to make further miniaturization and weight reduction difficult.

Referring to fig. 1 to 4b, an embodiment of the present application provides a three-mode dielectric resonator 1, which is applied to a dielectric filter, wherein the three-mode dielectric resonator 1 includes a dielectric body 10, and the dielectric body 10 can be used as a dielectric resonator of the dielectric filter. When the three-mode dielectric resonator 1 has a conductive layer, the conductive layer may cover the surface of the dielectric body 10. The dielectric body 10 is provided with a first resonance blind hole 11, a second resonance blind hole 12 and a third resonance blind hole 13 respectively, the first resonance blind hole 11 is used for forming a first resonance mode, the second resonance blind hole 12 is used for forming a second resonance mode, the third resonance blind hole 13 is used for forming a third resonance mode, and the first resonance mode, the second resonance mode and the third resonance mode are quasi-TEM modes.

It will be appreciated that the TEM mode is a transverse electromagnetic wave (TRANSVERSE ELECTROMAGNETIC WAVE, TEM) mode in which the electric and magnetic fields of the electromagnetic wave have no components in the direction of propagation of the electromagnetic wave; since the TEM mode is an ideal mode, it is difficult to realize in practice, and a mode close to the TEM mode is referred to as a quasi-TEM mode, in which the components of the electric field and the magnetic field in the propagation direction of the electromagnetic wave are much smaller than those of the electric field and the magnetic field in the direction perpendicular to the propagation direction of the electromagnetic wave.

Fig. 2a and 2b show an electric field distribution diagram and a magnetic field distribution diagram of a first resonance mode of the triple-mode dielectric resonator 1, respectively, fig. 3a and 3b show an electric field distribution diagram and a magnetic field distribution diagram of a second resonance mode of the triple-mode dielectric resonator 1, respectively, and fig. 4a and 4b show an electric field distribution diagram and a magnetic field distribution diagram of a third resonance mode of the triple-mode dielectric resonator 1, respectively, as can be seen from the figures, the first resonance mode, the second resonance mode and the third resonance mode are all quasi TEM modes.

It should be understood that the shape, size (including depth, caliber, inner diameter, etc.), arrangement position, etc. of the first, second, and third blind resonant holes 11, 12, and 13 have various embodiments, as long as the first, second, and third blind resonant holes 11, 12, and 13 can be used to form a quasi TEM mode, respectively. The first, second and third blind resonant holes 11, 12 and 13 may be blind holes of various shapes, such as, but not limited to, cylindrical, polygonal cylindrical, elliptic cylindrical, conical, pyramidal, etc. The shape or size of the first resonant blind hole 11, the second resonant blind hole 12 and the third resonant blind hole 13 may be the same, or may be a shape or size in which at least one resonant blind hole is different from the shape of the other resonant blind holes.

As can be seen from the above, in the three-mode dielectric resonator 1 provided in the embodiment of the present application, the dielectric body 10 is provided with the first resonant blind hole 11, the second resonant blind hole 12, and the third resonant blind hole 13, respectively, the first resonant blind hole 11 is used to form a first resonant mode, the second resonant blind hole 12 is used to form a second resonant mode, and the third resonant blind hole 13 is used to form a third resonant mode, so that three resonant modes can be implemented by a single dielectric resonator, that is, three resonant modes can be formed in the same dielectric resonator, the space utilization of the dielectric resonator can be effectively improved, the space utilization of the dielectric resonator is 3 times that of the single-mode dielectric resonator, is 1.5 times that of the dual-mode dielectric resonator, and the number of the dielectric resonator can be reduced under the same volume, thereby facilitating further miniaturization and light weight of the dielectric filter.

Meanwhile, the first resonance mode, the second resonance mode and the third resonance mode are quasi-TEM modes, compared with the TE mode and the TM mode, the thickness and the volume of the dielectric body 10 can be effectively reduced, the space utilization rate of the dielectric resonant cavity is further improved, the volume and the weight of the dielectric filter are further reduced, and on the other hand, the second harmonic frequency of the dielectric filter is about 1.3-1.7 times of the resonance frequency of the fundamental mode due to the resonance characteristic of the quasi-TEM mode, so that the second harmonic of the dielectric filter is farther away from the passband, and the dielectric filter has more excellent out-of-band rejection performance and is beneficial to improving the index performance of the dielectric filter.

It should be noted that, in the present application, the terms "first", "second", "third" in the first resonant blind hole 11, the second resonant blind hole 12, the third resonant blind hole 13, and the first resonant mode, the second resonant mode, the third resonant mode, etc. are only for convenience of description and illustration, and are not to be construed as indicating or implying the signal transmission sequence in the three-mode dielectric resonator, the ordering of the three resonant modes, and the arrangement sequence of the resonant blind holes corresponding to the three resonant modes.

It should be understood that the first resonant blind hole 11, the second resonant blind hole 12, and the third resonant blind hole 13 are merely for distinguishing different resonant blind holes, and are not limited in order, and the first resonant blind hole 11 may be named as a second resonant blind hole or a third resonant blind hole, the second resonant blind hole 12 may be named as a first resonant blind hole or a third resonant blind hole, and the third resonant blind hole 13 may be named as a first resonant blind hole or a second resonant blind hole, and the first resonant mode, the second resonant mode, and the third resonant mode may be changed accordingly without departing from the scope of the various described embodiments.

It should be understood that the main transmission path or main coupling path of the signal in the three-mode dielectric resonator 1 may be a first resonance mode-a second resonance mode-a third resonance mode, or may be a first resonance mode-a third resonance mode-a second resonance mode, or may be a second resonance mode-a third resonance mode-a first resonance mode-a third resonance mode, or may be a third resonance mode-a second resonance mode-a first resonance mode, or may be a third resonance mode-a first resonance mode-a second resonance mode.

For convenience of description and understanding, in the embodiment of the present application, a main transmission path or a main coupling path of a signal in the three-mode dielectric resonator 1 is defined as a first resonance mode-a second resonance mode-a third resonance mode, which is described and illustrated as an example.

In one embodiment, the three-mode dielectric resonator 1 further includes a first conductive layer 210, where the first conductive layer 210 may cover the outer surface of the dielectric body 10, the inner surface of the first blind resonant hole 11, the inner surface of the second blind resonant hole 12, and the inner surface of the third blind resonant hole 13, so as to facilitate shielding from external interference and prevent internal signal leakage.

In one embodiment, the dielectric body 10 may be a ceramic dielectric body made of a ceramic material, but is not limited thereto, and the dielectric body may be made of any nonmetallic dielectric material with a relative dielectric constant of 1-1000.

In one embodiment, the depth of the first resonant blind hole 11, the depth of the second resonant blind hole 12, and the depth of the third resonant blind hole 13 may be close to or about a quarter of the operating wavelength, which is advantageous not only for forming the quasi-TEM mode, but also for further reducing the volume of the dielectric body, thereby facilitating further miniaturization and weight saving of the dielectric filter.

It should be noted that the depth of the first resonant blind hole 11, the depth of the second resonant blind hole 12, and the depth of the third resonant blind hole 13 are not limited to be close to or about one-fourth of the operating wavelength, and in other embodiments, the depth of the first resonant blind hole 11, the depth of the second resonant blind hole 12, and the depth of the third resonant blind hole 13 may be close to or about one-half or three-quarters of the operating wavelength.

In one embodiment, referring to FIG. 1, the media body 10 has a first plane 101, a second plane 102, and a third plane 103, any two of the first plane 101, the second plane 102, and the third plane 103 being non-parallel to one another; the first plane 101 is provided with a first resonance blind hole 11, the second plane 102 is provided with a second resonance blind hole 12, and the third plane 103 is provided with a third resonance blind hole 13.

So set up, because first resonance blind hole 11, second resonance blind hole 12, third resonance blind hole 13 locate different planes respectively, compare in two or three resonance blind holes setting up in the coplanar of dielectric body 10, can disperse each resonance blind hole on the volume occupation on dielectric body 10 on the one hand, avoid a plurality of resonance blind holes to locate the coplanar and lead to single planar area to increase, make space planning more reasonable, do benefit to the improvement space utilization, further reduce the volume of dielectric body 10, on the other hand can avoid setting up the electric coupling between two resonance modes that correspond when roughly parallel between two resonance blind holes on the coplanar weaker, can make have certain distance between two resonance blind holes, in order to do benefit to the coupling between two resonance modes, and then can improve the flexibility of controlling the coupling mode between two resonance modes.

Optionally, in one embodiment, referring to fig. 1, the first plane 101, the second plane 102, and the third plane 103 are perpendicular to each other; that is, the first plane 101 is perpendicular to the second plane 102, the second plane 102 is perpendicular to the third plane 103, and the first plane 101 is perpendicular to the third plane 103. The depth direction h1 of the first resonance blind hole 11, the depth direction h2 of the second resonance blind hole 12 and the depth direction h3 of the third resonance blind hole 13 are perpendicular to each other; that is, the depth direction h1 of the first blind resonant hole 11 is perpendicular to the depth direction h2 of the second blind resonant hole 12, the depth direction h2 of the second blind resonant hole 12 is perpendicular to the depth direction h3 of the third blind resonant hole 13, and the depth direction h1 of the first blind resonant hole 11 is perpendicular to the depth direction h3 of the third blind resonant hole 13.

So set up, because the every two mutual verticals of first plane 101, second plane 102 and third plane 103, the depth direction of first resonance blind hole 11, the depth direction of second resonance blind hole 12 and the depth direction of third resonance blind hole 13 are mutual verticals for each resonance blind hole's arrangement can disperse relatively, not only can make each resonance blind hole set up more reasonable and do benefit to further improvement space utilization on medium body 10, but also further do benefit to the coupling between the resonance modes that two resonance blind holes correspond. Meanwhile, under the condition, the first resonance blind hole 11, the second resonance blind hole 12 and the third resonance blind hole 13 are vertical holes, so that compared with an inclined hole, the processing and manufacturing are facilitated, the production and processing difficulty can be reduced, and the production efficiency is improved.

Alternatively, referring to fig. 1, the first plane 101, the second plane 102 and the third plane 103 are directly connected. Of course, in other embodiments, the first plane 101, the second plane 102, and the third plane 103 may also be indirectly connected by an intermediate connection plane.

It should be noted that, the first plane 101, the second plane 102, and the third plane 103 are not limited to being perpendicular to each other; in other embodiments, it is also possible that at least one of the planes is inclined to the other planes. The depth direction of the first blind resonance hole 11, the depth direction of the second blind resonance hole 12, and the depth direction of the third blind resonance hole 13 are not limited to be perpendicular to each other; in other embodiments, it is also possible that the depth direction of at least one of the blind resonant holes is inclined or parallel to the depth direction of the other blind resonant holes.

It should be noted that the first resonant blind hole 11, the second resonant blind hole 12, and the third resonant blind hole 13 are not limited to being disposed on different planes, respectively. Alternatively, in other embodiments, at least two of the first resonant blind hole 11, the second resonant blind hole 12 and the third resonant blind hole 13 may be disposed on the same plane; in this case, the depth directions of the two resonant blind holes disposed on the same plane may be parallel to each other or inclined to each other.

In one embodiment, referring to fig. 1, the dielectric body 10 has a rectangular parallelepiped structure, and may have a rectangular parallelepiped structure with different length, width and height, or a square structure with the same length, width and height.

The dielectric body 10 with the cuboid structure is convenient to produce in a quasi-TEM mode, convenient to produce, process and manufacture, capable of reducing production and processing difficulty and improving production efficiency, and convenient to match with external equipment, such as a base station, compared with other shapes.

It should be noted that the dielectric body 10 is not limited to a rectangular parallelepiped structure, and in other embodiments, the dielectric body 10 may have a polyhedral structure or a cylindrical structure with other shapes.

In one embodiment, referring to fig. 5 to 9, the dielectric body 10 is provided with a first hybrid coupling structure 14, and the first hybrid coupling structure 14 is used for performing hybrid coupling between the second resonant mode and the third resonant mode to generate a transmission zero.

It is understood that hybrid coupling, including both magnetic and electrical coupling, refers to both magnetic and electrical coupling between two resonant modes. The first hybrid coupling structure 14 may be a structure of various shapes that enables hybrid coupling between two resonant modes.

The arrangement enables the second resonant mode and the third resonant mode to be in mixed coupling through the first mixed coupling structure 14, so that a transmission zero point is formed by the dielectric filter of the dielectric body 10, and the out-of-band rejection performance of the dielectric filter is improved; and the strength of the magnetic coupling and the electric coupling can be controlled by setting the structure of the first hybrid coupling structure 14, namely, the position of the transmission zero point can be controlled, so that the transmission zero point of the dielectric filter has controllability.

Regarding the hybrid coupling, the following description will be further presented:

k_mix＝k_m+k_e

Wherein k _mix represents the total coupling coefficient, which is the superposition of the magnetic coupling and the electric coupling coefficient, i.e. the hybrid coupling coefficient; k _m represents the magnetic coupling coefficient; k _e denotes an electric coupling coefficient. If k _m/k_e is close to 1, then the hybrid coupling may produce a transmission zero. With k _mix kept unchanged, the strength of the transmission zero generated by the hybrid coupling can be controlled by controlling the ratio of k _m to k _e. The closer the i k _m/k_e is to 1, the stronger the transmission zero, the closer the transmission zero is to the passband of the filter, and conversely the weaker the transmission zero is. Where k _m/k_e is the absolute value of the ratio of k _m to k _e.

When |k _m/k_e | is close to 1 and the hybrid coupling is generally represented as magnetic coupling (i.e., magnetic coupling predominates), i.e., k _mix > 0, the transmission zero is at the high end;

When k _m/k_e approaches 1 and the hybrid coupling is generally represented as an electrical coupling (i.e., electrical coupling predominates), i.e., k _mix < 0, the transmission zero is at the low end.

Alternatively, in one embodiment, referring to fig. 5-9, the first hybrid coupling structure 14 includes a first magnetic coupling slot 141 and a first electrical coupling structure 142. The two ends of the first magnetic coupling groove 141 are respectively connected to the second resonant blind hole 12 and the third resonant blind hole 13, so as to magnetically couple the second resonant mode and the third resonant mode. The first electrical coupling structure 142 is located between the second resonant blind hole 12 and the third resonant blind hole 13 for electrically coupling between the second resonant mode and the third resonant mode.

Thus, the first magnetic coupling groove 141 can enhance the magnetic coupling between the second resonant mode and the third resonant mode, and the first electric coupling structure 142 can enhance the electric coupling between the second resonant mode and the third resonant mode, so that the second resonant mode and the third resonant mode are subjected to hybrid coupling, thereby being beneficial to the transmission zero point of the dielectric filter. Moreover, the shape and the structure of the first magnetic coupling groove 141 and the first electric coupling structure 142 are controlled independently according to the requirement, so that the magnetic coupling and the electric coupling between the second resonance mode and the third resonance mode are controlled, and the position of the transmission zero point is controlled; that is, the shape and structure of the first magnetic coupling groove 141 and the first electric coupling structure 142 can be controlled to lead the hybrid coupling to magnetic coupling, and further lead the transmission zero point to be positioned at the high end side of the passband; alternatively, the shape and structure of the first magnetic coupling slot 141 and the first electric coupling structure 142 may be controlled, so that the hybrid coupling is mainly electric coupling, and the transmission zero is located at the low end side of the passband.

Alternatively, the first conductive layer 210 may cover the inner surface of the first magnetic coupling groove 141.

Alternatively, referring to fig. 5 to 9, the first magnetic coupling groove 141 is a blind groove structure formed on the surface of the dielectric body 10, so as to facilitate the processing and manufacturing of the first magnetic coupling groove 141. The two ends of the first magnetic coupling groove 141 are respectively communicated with the orifice of the second resonant blind hole 12 and the orifice of the third resonant blind hole 13, and as the magnetic field at the orifice of the resonant blind hole is strongest, the first magnetic coupling groove 141 with the two ends respectively connected with the orifice of the second resonant blind hole 12 and the orifice of the third resonant blind hole 13 can strengthen the magnetic field energy transfer between the second resonant mode and the third resonant mode, and strengthen the magnetic coupling between the second resonant mode and the third resonant mode.

For example, referring to fig. 6, the first magnetic coupling slot 141 includes a first slot segment 1411, a second slot segment 1412 and a third slot segment 1413 that are sequentially connected, one end of the first slot segment 1411 is connected to the aperture of the second resonant blind hole 12, one end of the second slot segment 1412 is connected to the other end of the first slot segment 1411 in a bending or turning manner, one end of the third slot segment 1413 is connected to the other end of the second slot segment 1412 in a bending or turning manner, and the other end of the third slot segment 1413 is connected to the aperture of the third resonant blind hole 13.

So configured, since the first magnetic coupling groove 141 includes multiple sections, the first magnetic coupling groove 141 is not only beneficial to communicating the second resonant blind hole 12 and the third resonant blind hole 13 which are opened on different planes of the dielectric body 10, but also beneficial to adjusting the shapes and the sizes (including depth, width, length, etc.) of the first groove section 1411, the second groove section 1412 and the third groove section 1413 respectively so as to adjust the coupling coefficient or the coupling strength between the second resonant mode and the third resonant mode.

Further, referring to fig. 6, the first slot 1411 may be formed in a plane in which the second blind resonant hole 12 is disposed, such as the second plane 102. The third slot 1413 may be open on a plane in which the third blind resonant hole 13 is disposed, such as the third plane 103. The second groove 1412 may be formed between the plane where the second blind resonant hole 12 is formed and the plane where the third blind resonant hole 13 is formed, for example, between the second plane 102 and the third plane 103, or on the intersection line of the second plane 102 and the third plane 103.

The arrangement is more beneficial to the first magnetic coupling groove 141 to communicate the second resonance blind hole 12 and the third resonance blind hole 13 which are arranged on different planes of the dielectric body 10, and is convenient for processing and manufacturing.

Further, referring to fig. 6 and 9, the second slot 1412 may be perpendicular to the first slot 1411, and the third slot 1413 may be perpendicular to the second slot 1412, which is more convenient for manufacturing.

Of course, the first magnetic coupling groove 141 is not limited to include the first groove section 1411, the second groove section 1412, and the third groove section 1413, but may be of various other shapes, for example, a polygonal line groove, an arc groove, and a groove including an arc structure and a linear structure, but is not limited thereto as long as the magnetic coupling between the second resonance mode and the third resonance mode can be enhanced.

It should be noted that, the first magnetic coupling groove 141 is not limited to be in communication with the aperture of the second blind resonance hole 12 and the aperture of the third blind resonance hole 13; in other embodiments, the first magnetic coupling groove 141 may also be in communication with the sidewall of the second blind resonant hole 12 and the sidewall of the third blind resonant hole 13. The first magnetic coupling groove 141 is not limited to be provided on the surface of the dielectric body 10, and in other embodiments, the first magnetic coupling groove 141 may be provided inside the dielectric body 10.

Optionally, referring to fig. 8 and 9, the first electrical coupling structure 142 is a blind trench structure, and the first electrical coupling structure 142 is connected to the third blind resonant hole 13, so as to enhance electrical coupling between the second resonant mode and the third resonant mode. Alternatively, the first conductive layer 210 may cover the inner surface of the first electrical coupling structure 142.

Alternatively, referring to fig. 8 and 9, the depth direction of the first electrically-coupled structure 142 is parallel to the depth direction of the third blind resonant hole 13. The first electrical coupling structure 142 is connected to the first magnetic coupling groove 141, and the depth H1 of the first electrical coupling structure 142 is greater than the depth H2 of the first magnetic coupling groove 141, i.e. the depth H1 of the first electrical coupling structure 142 is greater than the depth H2 of a groove segment of the first magnetic coupling groove 141 connected to the first electrical coupling structure 142. Specifically, the first electrical coupling structure 142 may communicate with the sidewall and the notch of the first magnetic coupling groove 141.

The first electrical coupling structure 142 has a certain depth to facilitate the electrical coupling between the second resonant mode and the third resonant mode, and the first electrical coupling structure 142 is connected to the third blind resonant hole 13 and the first magnetic coupling slot 141, so as to facilitate the production and manufacture, and reduce the difficulty of the production and manufacture.

It should be understood that the depth H1 of the first electrical coupling structure 142 refers to the vertical distance between the notch of the first electrical coupling structure 142 and the bottom of the groove, and the depth H2 of the first magnetic coupling groove 141 refers to the vertical distance between the notch of the first magnetic coupling groove 141 and the bottom of the groove.

Optionally, referring to fig. 9, the depth H1 of the first electrical coupling structure 142 is greater than or equal to half the depth of the third resonant blind hole 13, so that the first electrical coupling structure 142 has a certain depth, and the electrical coupling strength between the second resonant mode and the third resonant mode can be improved.

It will be appreciated that the coupling strength or coupling coefficient between the second and third resonant modes may be adjusted by adjusting the depth H1 and width L1 of the first electrical coupling structure 142. The width L1 of the first electrical coupling structure 142 refers to a distance between a side of the first electrical coupling structure 142 close to the third blind resonant hole 13 and a side far from the third blind resonant hole 13, and by adjusting the width L1 of the first electrical coupling structure 142, a distance between the first electrical coupling structure 142 and the second blind resonant hole 12 can be adjusted.

Illustratively, the deeper the depth H1 of the first electrical coupling structure 142, the stronger the electrical coupling strength between the second and third resonant modes, and vice versa. Especially, when the depth direction of the second resonant blind hole 12 is perpendicular to the depth direction of the third resonant blind hole 13 and the first electrical coupling structure 142 is communicated with the third resonant blind hole 13, the distance between the end of the bottom of the second resonant blind hole 12 and the end of the bottom of the third resonant blind hole 13 is relatively short, so that the electrical coupling strength between the second resonant mode and the third resonant mode can be further improved.

Illustratively, the greater the width L1 of the first electrical coupling structure 142, the smaller the distance between the first electrical coupling structure 142 and the second blind resonant hole 12, the stronger the electrical coupling strength between the second resonant mode and the third resonant mode, and vice versa.

It should be noted that the structure of the first electrical coupling structure 142 is not limited to a blind via structure communicating with the third blind resonant hole 13. In other embodiments, the first electric coupling structure 142 may be a hole or a slot not in communication with the second blind resonant hole 12 and the third blind resonant hole 13, for example, a hole or a slot for forming a capacitive coupling rod structure between the second blind resonant hole 12 and the third blind resonant hole 13 (for example, a first conductive layer 210 is disposed on an outer surface of the dielectric body 10, a second conductive layer 220 is disposed on the first electric coupling structure 142, and the second conductive layer 220 is electrically insulated from the first conductive layer 210, so as to form the capacitive coupling rod structure), which may also enhance the electric coupling between the second resonant mode and the third resonant mode.

As can be seen from the above embodiments, by adjusting the structure of the first magnetic coupling slot 141, for example, by adjusting the shape and/or size (the size may be depth, width, etc.) of the first magnetic coupling slot 141, the magnetic coupling strength between the second resonant mode and the third resonant mode can be adjusted, by adjusting the structure of the first electric coupling structure 142, for example, by adjusting the shape and/or size (the size may be depth, width, etc.) of the first electric coupling structure 142, the electric coupling strength between the second resonant mode and the third resonant mode can be adjusted, so that the coupling between the second resonant mode and the third resonant mode is mainly magnetic coupling or mainly electric coupling, thereby controlling the ratio of the magnetic coupling and the electric coupling between the transmission zero point and the passband at the high end or the low end of the passband, and thereby controlling the distance between the transmission zero point and the passband.

It should be noted that the first hybrid coupling structure 14 may not include the first magnetic coupling groove 141 and the first electric coupling structure 142.

Alternatively, in other embodiments, the first hybrid coupling structure 14 may include a coupling blind slot between the second resonant blind hole 12 and the third resonant blind hole 13, so that the second resonant mode and the third resonant mode can be electrically coupled, and meanwhile, the second resonant mode and the third resonant mode are magnetically coupled, that is, the coupling blind slot does not block the second resonant mode and the third resonant mode from being magnetically coupled, and the second resonant mode and the third resonant mode can be hybrid coupled.

Alternatively, in other embodiments, the first hybrid coupling structure 14 may include a slot or aperture for forming a capacitive coupling rod structure for electrically coupling between the second resonant mode and the third resonant mode, while also magnetically coupling between the second resonant mode and the third resonant mode, i.e., the slot or aperture for forming the capacitive coupling rod structure does not block the magnetic coupling between the second resonant mode and the third resonant mode, as well as allowing hybrid coupling between the second resonant mode and the third resonant mode.

In order to realize transmission zero point, the dielectric filter in the prior art needs to set at least three dielectric resonant cavities for coupling, that is, needs to set at least three dielectric bodies to form cross coupling among resonant modes, resulting in larger volume and weight. And its transmission zero is at most N-2, where N represents the total number of resonant modes.

In order to solve the above technical problems, in the three-mode dielectric resonator 1 provided in the embodiment of the present application, a transmission zero point can be generated by performing hybrid coupling between the second resonant mode and the third resonant mode, on the basis of which, in order to achieve that a single dielectric resonator has a plurality of transmission zero points, that is, in order to increase the number of transmission zero points that can be generated on the same dielectric body 10 and further enhance the out-of-band rejection performance of the three-mode dielectric resonator 1, optionally, in one embodiment, the first resonant mode, the second resonant mode and the third resonant mode are mutually coupled in pairs, that is, in addition to performing hybrid coupling between the second resonant mode and the third resonant mode, the first resonant mode and the second resonant mode are both coupled, so that cross coupling can be formed between the first resonant mode and the third resonant mode, so as to facilitate the generation of a transmission zero point, that two transmission zero points can be generated in the single dielectric resonator 1, and the volume and weight of a filter adopting the three-mode dielectric resonator 1 can be effectively reduced, and the weight of the filter can be further reduced.

It can be understood that the cross coupling between the first resonant mode and the third resonant mode can be controlled to be capacitive cross coupling or inductive cross coupling, the coupling between the first resonant mode and the second resonant mode can be controlled to be magnetic coupling or electric coupling as a whole, and the mixed coupling between the second resonant mode and the third resonant mode can be controlled to be dominant magnetic coupling or electric coupling, so that the coupling property on the signal transmission path can be controlled, and the position of the zero point generated by the cross coupling can be controlled to be high-end or low-end; the transmission zero resulting from the cross-coupling between the first and third resonant modes is also a controllable transmission zero.

Illustratively, when the coupling between the first resonant mode and the second resonant mode is wholly represented as magnetic coupling, if the hybrid coupling between the second resonant mode and the third resonant mode is predominantly magnetic coupling, the cross coupling between the first resonant mode and the third resonant mode is represented as capacitive cross coupling, the zero point generated by the cross coupling is at the low end, and if the hybrid coupling between the second resonant mode and the third resonant mode is predominantly electrical coupling, the cross coupling between the first resonant mode and the third resonant mode is represented as capacitive cross coupling, the zero point generated by the cross coupling is at the high end.

Referring to the following table, the following table exemplarily shows the relationship between the coupling property on the signal transmission path and the positions and the numbers of transmission zeros in the three-mode dielectric resonator 1 according to the embodiment of the present application.

/>

It can be seen that the position of the transmission zero point generated by the hybrid coupling can be controlled by controlling the shape structure of the first hybrid coupling structure 14, and the position of the transmission zero point generated by the cross coupling can be controlled by controlling the coupling properties among the first resonant mode, the second resonant mode and the third resonant mode, so that the two transmission zero points can be located at the low end and the high end respectively, or both the two transmission zero points can be located at the high end or both the low end, and both the two transmission zero points are controllable transmission zero points.

In one embodiment, referring to fig. 5 to 9, a second magnetic coupling groove 151 is disposed on the dielectric body 10, and two ends of the second magnetic coupling groove 151 are respectively connected to the first blind resonant hole 11 and the second blind resonant hole 12 for performing magnetic coupling between the first resonant mode and the second resonant mode. The dielectric body 10 is provided with an electric coupling blocking structure 152, and the electric coupling blocking structure 152 is located between the first resonant blind hole 11 and the second resonant blind hole 12 and is used for blocking electric coupling between the first resonant mode and the second resonant mode.

In this way, the second magnetic coupling groove 151 can be used for magnetic coupling between the first resonant mode and the second resonant mode, and the electric coupling blocking structure 152 can block the electric coupling between the first resonant mode and the second resonant mode, so that the coupling between the first resonant mode and the second resonant mode is wholly represented as magnetic coupling.

Alternatively, the first conductive layer 210 may cover the inner surface of the second magnetic coupling groove 151.

Alternatively, referring to fig. 5 to 9, the second magnetic coupling groove 151 may be a blind groove structure formed on the surface of the dielectric body 10, so as to facilitate manufacturing of the second magnetic coupling groove 151. The two ends of the second magnetic coupling groove 151 are respectively communicated with the orifice of the first resonant blind hole 11 and the orifice of the second resonant blind hole 12, and the magnetic field at the orifice of the resonant blind hole is strongest, so that the magnetic field energy transfer between the first resonant mode and the second resonant mode is enhanced, and the magnetic coupling between the first resonant mode and the second resonant mode is enhanced.

Optionally, the structure of the second magnetic coupling groove 151 may be similar to that of the first magnetic coupling groove 141, i.e. may include three groove segments, which is not only beneficial for the second magnetic coupling groove 151 to communicate between the first resonant blind hole 11 and the second resonant blind hole 12 opened on different planes of the dielectric body 10, but also beneficial for adjusting the shape and size (including depth, width and length) of each groove segment to adjust the coupling strength between the first resonant mode and the second resonant mode.

For example, referring to fig. 7 and 9, the second magnetic coupling groove 151 includes a fourth groove segment 1511, a fifth groove segment 1512 and a sixth groove segment 1513, which are sequentially connected, one end of the fourth groove segment 1511 is connected to the aperture of the first resonant blind hole 11, one end of the fifth groove segment 1512 is connected to the other end of the fourth groove segment 1511 in a bending or turning manner, one end of the sixth groove segment 1513 is connected to the other end of the fifth groove segment 1512 in a bending or turning manner, and the other end of the sixth groove segment 1513 is connected to the aperture of the second resonant blind hole 12.

It will be appreciated that by adjusting the shape and dimensions (including depth, width, length, etc.) of the fourth slot segment 1511, fifth slot segment 1512, and sixth slot segment 1513, respectively, the coupling strength or coupling coefficient between the first resonant mode and the second resonant mode can be adjusted.

Illustratively, referring to fig. 9, the deeper the depth H3 of the fourth slot segment 1511, the stronger the coupling strength between the first and second resonant modes, within a certain range. Or as the depth H3 of the fourth slot segment 1511 increases, the coupling strength between the first resonant mode and the second resonant mode decreases and then increases. The depth H3 of the fourth groove segment 1511 refers to a vertical distance between the groove opening of the fourth groove segment 1511 and the groove bottom.

Of course, the second magnetic coupling groove 151 may be any other shape, for example, a polygonal line groove, an arc groove, or a groove including an arc structure and a linear structure, but is not limited thereto, as long as the magnetic coupling between the first resonant mode and the second resonant mode can be enhanced.

The second magnetic coupling groove 151 is not limited to be opened on the surface of the dielectric body 10; in other embodiments, the second magnetic coupling groove 151 may be formed inside the dielectric body 10.

It should be appreciated that the electrical coupling blocking structure 152 blocks electrical coupling between the first resonant mode and the second resonant mode, and is not limited to a complete blocking such that electrical coupling between the first resonant mode and the second resonant mode is not performed, but at least blocks portions to weaken the electrical coupling strength between the first resonant mode and the second resonant mode.

Alternatively, referring to fig. 5, 7 and 9, the electric coupling blocking structure 152 is a through slot penetrating through opposite sides of the dielectric body 10, so as to be blocked between one end of the bottom of the first resonant blind hole 11 and one end of the bottom of the second resonant blind hole 12, so as to effectively improve the effect of blocking electric coupling between the first resonant mode and the second resonant mode. Alternatively, the first conductive layer 210 may cover the inner surface of the electrical coupling blocking structure 152.

It is understood that the electrical coupling blocking structure 152 may be a through slot of various shapes, such as, but not limited to, a rectangular parallelepiped shape, an elliptic cylinder shape, a bent plate shape, a curved plate shape, etc.

It will also be appreciated that by adjusting the shape and dimensions (including width, length, and depth) of the electrical coupling blocking structure 152, the effect of the electrical coupling blocking structure 152 blocking electrical coupling between the first resonant mode and the second resonant mode can be adjusted.

Illustratively, referring to fig. 9, the greater the length N1 of the electrical coupling blocking structure 152, the smaller the coupling coefficient or the weaker the coupling strength between the first and second resonant modes.

Of course, in other embodiments, the electrical coupling blocking structure 152 may be a blind trench or a blind via, and is located between the end of the bottom of the first resonant blind via 11 and the end of the bottom of the second resonant blind via 12, so as to block the electrical coupling between the first resonant mode and the second resonant mode.

It should be noted that the second magnetic coupling groove 151 and the electric coupling blocking structure 152 need not be provided on the dielectric body 10 at the same time.

Alternatively, in other embodiments, the dielectric body 10 may not be provided with the second magnetic coupling groove 151, but only the electric coupling blocking structure 152 may be provided to facilitate the coupling between the first resonant mode and the second resonant mode to be entirely represented as magnetic coupling by blocking the electric coupling between the first resonant mode and the second resonant mode.

Alternatively, in other embodiments, the dielectric body 10 may not be provided with the electric coupling blocking structure 152, but only the second magnetic coupling groove 151 may be provided, so that the coupling between the first resonant mode and the second resonant mode may be entirely represented as magnetic coupling, or hybrid coupling may be performed between the first resonant mode and the second resonant mode.

In the above-described embodiment, by providing the second magnetic coupling groove 151 and the electric coupling blocking structure 152 on the dielectric body 10, it is achieved that the coupling between the first resonance mode and the second resonance mode is entirely expressed as magnetic coupling. The coupling between the first resonant mode and the second resonant mode is not limited to being entirely represented as magnetic coupling.

Alternatively, in other embodiments, the coupling between the first resonant mode and the second resonant mode may also be represented as an electrical coupling as a whole; for example, an electrical coupling structure (may be a blind hole, a blind groove, a structure for forming a capacitive coupling rod structure, etc., but not limited thereto) may be disposed between the first resonant blind hole 11 and the second resonant blind hole 12, or a blind groove facing the second resonant blind hole 12 may be disposed on a hole bottom wall or a hole side wall of the first resonant blind hole 11, or a blind groove facing the first resonant blind hole 11 may be disposed on a hole bottom wall or a hole side wall of the first resonant blind hole 11 and a blind groove facing each other may be disposed on a hole bottom wall or a hole side wall of the second resonant blind hole 12, respectively, wherein the position, shape, and structure of the blind groove may refer to the first electrical coupling structure 142).

In one embodiment, referring to fig. 5 and 9, the dielectric body 10 is provided with a second electrical coupling structure 16, and the second electrical coupling structure 16 is located between the first resonant blind hole 11 and the third resonant blind hole 13, for electrically coupling between the first resonant mode and the third resonant mode to form cross coupling; that is, when the main transmission path or the main coupling path of the signal in the three-mode dielectric resonator 1 is the first resonant mode-the second resonant mode-the third resonant mode, the first resonant mode and the third resonant mode are also coupled, so that the first resonant mode and the third resonant mode are cross-coupled; at the same time, the arrangement of the second electrical coupling structure 16 also makes the property of cross coupling between the first and third resonant modes appear as capacitive cross coupling.

It is understood that the second electric coupling structure 16 may be a structure of various shapes capable of enhancing electric coupling between the first resonant mode and the third resonant mode, such as an electric coupling groove, an electric coupling hole, a structure for forming a capacitively coupled flying bar structure, etc., but is not limited thereto.

Alternatively, in one embodiment, referring to fig. 5 and 9, the second electrical coupling structure 16 includes a first blind slot 161 and a second blind slot 162. The first blind groove 161 is formed on the surface of the dielectric body 10 and is located between the first blind resonant hole 11 and the third blind resonant hole 13. The second blind groove 162 is formed in the bottom wall of the first blind groove 161. Wherein, the first blind groove 161 and the second blind groove 162 form a stepped blind groove structure. Further, the three-mode dielectric resonator 1 further includes a second conductive layer 220, and the second conductive layer 220 covers the inner surface of the second blind trench 162. The inner surface of the first blind via 161 is exposed to electrically insulate the second conductive layer 220 from the first conductive layer 210.

So arranged, the first blind groove 161 and the second blind groove 162 form a stepped blind groove structure, so that different treatments are carried out on the inner surfaces of the first blind groove 161 and the second blind groove 162; when the first conductive layer 210 covers the surface of the dielectric body 10, the inner surface of the first blind trench 161 is not covered, so that the inner surface of the first blind trench 161 is exposed, and the second conductive layer 220 covers the inner surface of the second blind trench 162, so that the second conductive layer 220 is electrically insulated from the first conductive layer 210, and at this time, the second blind trench 162 and the second conductive layer 220 can form a capacitive coupling flying bar structure, so as to facilitate the electrical coupling between the first resonant mode and the third resonant mode to form cross coupling, and the property of the cross coupling is expressed as capacitive cross coupling.

It is understood that the first conductive layer 210 and the second conductive layer 220 may be various conductive layers, for example, a metal layer, and a material of the metal layer may be silver, gold, copper, or the like, but is not limited thereto. The material of the second conductive layer 220 may be the same as or different from the material of the first conductive layer 210.

Alternatively, referring to fig. 5 and 9, the first blind groove 161 and the second blind groove 162 may each have an L-shape or a bent shape, so that when the depth direction of the first resonant blind hole 11 is perpendicular to or inclined with the depth direction of the second resonant blind hole 12, two ends of the first blind groove 161 and the second blind groove 162 having the L-shape or the bent shape may face the first resonant blind hole 11 and the second resonant blind hole 12, respectively, so as to enhance the electrical coupling between the first resonant mode and the third resonant mode.

Of course, the shapes of the first blind groove 161 and the second blind groove 162 are not limited thereto, and other blind grooves of various shapes such as an elongated shape, an arc shape, a U shape, etc. may be used.

It will be appreciated that by adjusting the shape and dimensions (including length, width, and depth) of the first and second blind slots 161, 162, the coupling strength or coupling coefficient between the first and third resonant modes may be adjusted.

Illustratively, referring to fig. 9, the deeper the depth H4 of the second blind trench 162, the greater the coupling coefficient between the first and third resonant modes. The greater the length N2 of the second blind slot 162, the greater the coupling coefficient between the first and third resonant modes.

It should be noted that the structure of the second electrical coupling structure 16 is not limited to a stepped blind groove structure. Alternatively, in other embodiments, the second electrical coupling structure 16 may also be a blind hole or blind slot that is not stepped; at this time, the second conductive layer 220 may be partially disposed on the inner surface of the blind via or the blind via, and partially exposed, so that the second conductive layer 220 is electrically insulated from the first conductive layer 210, and the capacitive coupling flying bar structure may be formed; of course, electrical coupling between the first resonant mode and the third resonant mode may also be performed when the first conductive layer 210 completely covers the inner surface of the second electrical coupling structure 16.

In the above embodiment, by providing the second electric coupling structure 16 on the dielectric body 10, the cross coupling between the first resonant mode and the third resonant mode is achieved, and the property of the cross coupling is expressed as capacitive cross coupling. The nature of the cross-coupling between the first and third resonant modes is not limited to exhibiting capacitive cross-coupling.

Alternatively, in other embodiments, the nature of the cross-coupling between the first resonant mode and the third resonant mode may also be manifested as inductive cross-coupling; for example, a magnetic coupling structure (such as a magnetic coupling groove communicating with the first resonant blind hole 11 and the third resonant blind hole 13, an electric coupling blocking structure for blocking electric coupling between the first resonant mode and the third resonant mode and allowing magnetic coupling between them) may be disposed between the first resonant blind hole 11 and the third resonant blind hole 13, but not limited thereto.

Alternatively, in other embodiments, there may be no coupling between the first resonant mode and the third resonant mode, i.e., neither magnetic nor electrical coupling occurs; for example, a coupling blocking structure (which may be, but is not limited to, a through hole, a through slot, etc.) may be disposed between the first and third blind resonant holes 11 and 13 to block coupling between the first and third resonant modes.

In order to achieve that the single dielectric resonator has a plurality of transmission zeros, that is, to increase the number of transmission zeros that can be generated on the same dielectric body 10 and further enhance the out-of-band rejection performance of the three-mode dielectric resonator 1, optionally, in another embodiment, a second hybrid coupling structure is provided on the dielectric body 10, and the second hybrid coupling structure is used for performing hybrid coupling between the first resonant mode and the second resonant mode to generate a transmission zero, so as to facilitate generation of a transmission zero, and at this time, two transmission zeros can be generated in the single dielectric resonator by the three-mode dielectric resonator 1.

It can be understood that the position of the transmission zero point generated by the hybrid coupling can be controlled by controlling the shape structure of the first hybrid coupling structure 14, and the position of the other transmission zero point generated by the hybrid coupling can be controlled by controlling the shape structure of the second hybrid coupling structure, so that the two transmission zero points can be located at the low end and the high end respectively, or both the two transmission zero points can be located at the high end or both the low ends.

It should be appreciated that the second hybrid coupling structure may take the same or similar structure as the first hybrid coupling structure 14 in the above-described embodiments, and of course, the structure of the second hybrid coupling structure may also be different from the structure of the first hybrid coupling structure 14 in the above-described embodiments.

Optionally, in one embodiment, referring to fig. 10, the second hybrid coupling structure includes a coupling blind hole 171, the coupling blind hole 171 being located between the first resonant blind hole 11 and the second resonant blind hole 12 for electrically coupling between the first resonant mode and the second resonant mode; the first resonant mode and the second resonant mode are also magnetically coupled, that is, the coupling blind hole 171 does not block the first resonant mode from being magnetically coupled with the second resonant mode, so that hybrid coupling between the first resonant mode and the second resonant mode can be performed.

So set up, when first hybrid coupling structure 14 includes first magnetic coupling groove 141 and first electric coupling structure 142, the second hybrid coupling structure is through setting up coupling blind hole 171 and can realize carrying out the hybrid coupling between first resonance mode and the second resonance mode, compare in the second hybrid coupling structure also adopts the same structure with first hybrid coupling structure 14, not only can simplify the structure complexity, do benefit to structural design, also do benefit to manufacturing, and the simplification of structure is convenient for control simultaneously the hybrid coupling between second resonance mode and the third resonance mode and the hybrid coupling between first resonance mode and the second resonance mode.

Alternatively, the first conductive layer 210 may cover the inner surface of the coupling blind hole 171.

Optionally, referring to fig. 10, the dielectric body 10 is provided with a coupling blocking structure 18, where the coupling blocking structure 18 is located between the first resonant blind hole 11 and the third resonant blind hole 13, and is used for blocking the coupling between the first resonant mode and the third resonant mode.

So configured, the cross-coupling between the first resonant mode and the third resonant mode can be cut off by blocking the coupling between the first resonant mode and the third resonant mode by the coupling blocking structure 18.

It is understood that the coupling blocking structure 18 may be a through slot, a via, etc. extending through opposite sides of the dielectric body 10, but is not limited thereto. The coupling blocking structure 18 may take various shapes such as, but not limited to, a rectangular parallelepiped shape, an elliptic cylinder shape, a bent plate shape, a curved plate shape, etc.

Alternatively, the first conductive layer 210 may cover the inner surface of the coupling barrier structure 18.

Alternatively, in another embodiment, where the second hybrid coupling structure is provided on the dielectric body 10, the first resonant mode and the third resonant mode may be coupled to form a cross coupling, where the cross coupling may generate a transmission zero, and then the three-mode dielectric resonator 1 may generate three controllable transmission zeros.

Optionally, in another embodiment, in the case that the second hybrid coupling structure is disposed on the dielectric body 10, a third hybrid coupling structure is further disposed on the dielectric body 10, where the third hybrid coupling structure is used for performing hybrid coupling between the first resonant mode and the third resonant mode, and may generate a transmission zero point, and meanwhile, the hybrid coupling between the first resonant mode and the third resonant mode also forms cross coupling, and the cross coupling may also generate a transmission zero point, so that the dielectric resonator 1 may generate four controllable transmission zero points.

It should be understood that the third hybrid coupling structure may adopt the same or similar structure as that of the first hybrid coupling structure 14 or the second hybrid coupling structure in the above-described embodiment, and is not described herein.

As can be seen from the above, the three-mode dielectric resonator 1 provided by the embodiment of the present application, a single dielectric resonator can provide two, three, or even four controllable transmission zeros, so that the dielectric filter employing the three-mode dielectric resonator 1 has better out-of-band rejection performance and rectangular coefficient, and the number of cross-couplings required by the dielectric filter can be effectively reduced, thereby reducing the number of dielectric resonators required by the dielectric filter, further reducing the volume of the dielectric filter, and further miniaturizing and lightening the dielectric filter. At the same time, the complexity of the topology and cross-coupling structure of the dielectric filter is reduced.

Referring to fig. 13 and 16, the embodiment of the present application further provides a dielectric filter 200, where the dielectric filter 200 includes at least one of the three-mode dielectric resonators 1 according to any of the above embodiments.

Because the dielectric filter 200 provided in the embodiment of the present application adopts the above-mentioned three-mode dielectric resonator 1, the same technical effects brought by the technical scheme of the three-mode dielectric resonator 1 in any of the above embodiments are also provided, and are not described herein.

Referring to fig. 7 to 12, an input coupling hole 191 is disposed on a dielectric body 10 of one of the three-mode dielectric resonators 1 of the dielectric filter 200, and the input coupling hole 191 is in communication or capacitive coupling with one of the first blind resonant hole 11, the second blind resonant hole 12, and the third blind resonant hole 13 of the dielectric body 10 for signal input. The dielectric body 10 of one of the three-mode dielectric resonators 1 of the dielectric filter 200 is provided with an output coupling hole 192, and the output coupling hole 192 is communicated or capacitively coupled with the other one of the first resonance blind hole 11, the second resonance blind hole 12 and the third resonance blind hole 13 on the dielectric body 10 for signal output.

It should be understood that the input coupling hole 191 and the output coupling hole 192 may be disposed on the same dielectric body 10, or may be disposed on different dielectric bodies 10 (adapted to the case where the dielectric filter 200 includes a plurality of three-mode dielectric resonators 1). So long as the signal can be input via the input coupling hole 191 and output via the output coupling hole 192.

Alternatively, the first conductive layer 210 may cover the inner surfaces of the input coupling hole 191 and the output coupling hole 192.

Alternatively, referring to fig. 9 and 10, the input coupling hole 191 communicates with the sidewall of the first blind resonant hole 11, and the output coupling hole 192 communicates with the sidewall of the third blind resonant hole 13.

Optionally, the input coupling hole 191 is capacitively coupled to the end where the hole bottom of the first blind resonant hole 11 is located, where the input coupling hole 191 is not communicated with the first blind resonant hole 11; the output coupling hole 192 is capacitively coupled to the end of the third blind resonant hole 13 where the bottom of the hole is located, and at this time, the output coupling hole 192 is not communicated with the third blind resonant hole 13.

The dielectric filter 200 may include one or more three-mode dielectric resonators 1. When the dielectric filter 200 includes a plurality of the three-mode dielectric resonators 1, the dielectric bodies 10 of the respective three-mode dielectric resonators 1 may be connected to form the dielectric assembly 100; the first conductive layers 210 of the respective three-mode dielectric resonators 1 may also be connected.

Illustratively, the dielectric filter 200 includes two three-mode dielectric resonators 1. Referring to fig. 11 and 12, dielectric bodies 10 of two three-mode dielectric resonators 1 of a dielectric filter 200 are connected through a coupling medium 130, and the coupling medium 130 is used for coupling the two three-mode dielectric resonators 1 to form a dielectric assembly 100. The first conductive layer 210 of the triple-mode dielectric resonator 1 may cover the coupling medium 130.

It will be appreciated that the structure of the dielectric bodies 10 of the two three-mode dielectric resonators 1 of the dielectric filter 200 may be the same or different.

Fig. 11 shows, as an example, a case where the dielectric bodies 10 of the two three-mode dielectric resonators 1 of the dielectric filter 200 are identical in structure. The third blind resonant hole 13 of the dielectric body 10 of one of the three-mode dielectric resonators 1 is coupled with the third blind resonant hole 13 of the dielectric body 10 of the other three-mode dielectric resonator 1 through the coupling medium 130.

Fig. 12 shows, as an example, a case where the dielectric bodies 10 of the two three-mode dielectric resonators 1 of the dielectric filter 200 are different in structure. The third blind resonant hole 13 of the dielectric body 10 of one of the three-mode dielectric resonators 1 is coupled with the third blind resonant hole 13 of the dielectric body 10 of the other three-mode dielectric resonator 1 through the coupling medium 130.

It is understood that the coupling medium 130 is made of a dielectric material, and may be made of a ceramic dielectric material or any other nonmetallic dielectric material; the material of the coupling medium 130 may be the same as or different from the material of the dielectric body 10 of the three-mode dielectric resonator 1.

Alternatively, the coupling medium 130 and the dielectric body 10 of the three-mode dielectric resonator 1 are integrally formed as a one-piece structure, i.e., the dielectric assembly 100 may be integrally formed as a one-piece structure.

By the arrangement, the coupling medium 130 and the medium body 10 of the three-mode medium resonator 1 do not need to be spliced or welded, only the sizes of the die and the processed medium combination 100 are required to be controlled in manufacturing, secondary tolerance generated by assembly and welding processes in the splicing and welding processes is avoided, the consistency of the medium combination 100 can be improved, the consistency of the medium filter 200 adopting the medium combination 100 is improved, the method is suitable for mass production and application, and the method has higher practical value.

In the dielectric filter in the prior art, two adjacent dielectric resonators are spliced and formed in a soldering mode, a silver soldering mode and the like, and a welding procedure is introduced in a manufacturing mode, so that extra manufacturing tolerance can be generated during splicing and welding, and the consistency and mass production of the dielectric filter are not facilitated.

Alternatively, referring to fig. 11 and 12, the input coupling hole 191 may be provided on the dielectric body 10 of one of the three-mode dielectric resonators 1, and the output coupling hole 192 may be provided on the dielectric body 10 of the other three-mode dielectric resonator 1.

Specifically, the input coupling hole 191 may be in communication with or capacitively coupled with the first blind resonant hole 11 of the dielectric body 10 of one of the three-mode dielectric resonators 1; the output coupling hole 192 may be in communication with or capacitively coupled to the first blind resonant hole 11 of the dielectric body 10 of the other three-mode dielectric resonator 1.

In one embodiment, the dielectric filter 200 further includes a metal film covering the opening of the slot or hole on the at least one dielectric body 10, and the slot or hole on the dielectric body 10 includes the slot or hole described in the above embodiments, such as the first blind resonant hole 11, the second blind resonant hole 12, the third blind resonant hole 13, the first magnetic coupling slot 141, the first electric coupling structure 142, the second magnetic coupling slot 151, the electric coupling blocking structure 152, the first blind slot 161, the second blind slot 162, the input coupling hole 191, the output coupling hole 192, and the like, but is not limited thereto. The metal film may be a film or foil of various metal materials, such as silver, gold, copper, etc., but is not limited thereto.

In this way, in the process of debugging the product by the dielectric filter 200, the conductive layer is not required to be removed from the outer surface of the dielectric filter 200, but the conductive layer is removed from the groove or the hole of the dielectric body 10, so that the packaging shielding can be performed by using the metal film, the metal film does not need to be directly contacted with the part of the dielectric body surface from which the conductive layer is removed, the performance of the product is not easily affected, the signal is not radiated to the outside to form mutual interference among the products when the product is applied, and the isolation performance among radio frequency links of the base station can be improved.

When the dielectric filter in the prior art is used for product debugging, the conducting layer on the outer surface or the corner cut of the dielectric body needs to be polished to adjust the frequency and the coupling; after debugging is finished, if the metal film is adopted for packaging, the metal film can be in direct contact with the surface of the polished conducting layer of the dielectric body, boundary conditions can be changed, the product performance is greatly affected, and therefore the metal film cannot be directly attached for packaging. If the shielding case is used for packaging, the size of the product can be greatly increased. If the package is not shielded, the part of the surface of the medium, from which the conductive layer is removed, radiates outwards signals, which can cause poor inter-link isolation and interference between the communication links in the base station, and affect the communication performance of the base station.

Illustratively, the dielectric filter 200 shown in fig. 13 employs the three-mode dielectric resonator 1 including the dielectric body 10 shown in fig. 5, and the dielectric body 10 includes the first magnetic coupling groove 141, the first electric coupling structure 142, the second magnetic coupling groove 151, the electric coupling blocking structure 152, the first blind groove 161, the second blind groove 162, the input coupling hole 191, and the output coupling hole 192. The first conductive layer 210 covers the inner surface of the first magnetic coupling groove 141, the inner surface of the first electric coupling structure 142, the inner surface of the second magnetic coupling groove 151, the inner surface of the electric coupling blocking structure 152, the inner surface of the input coupling hole 191, and the inner surface of the output coupling hole 192. The second conductive layer 220 covers the inner surfaces of the second blind trenches 162.

Fig. 14 is a schematic diagram of a topology of the dielectric filter 200 shown in fig. 13, in which a letter S represents an input signal, a letter L represents an output signal, a numeral 1 represents a first resonant mode, a numeral 2 represents a second resonant mode, a numeral 3 represents a third resonant mode, a solid line represents magnetic coupling between the two resonant modes, and a broken line represents electrical coupling between the two resonant modes. As can be seen from fig. 14, the coupling between the first resonant mode and the second resonant mode is wholly represented by magnetic coupling, the hybrid coupling is performed between the second resonant mode and the third resonant mode, and the coupling between the first resonant mode and the third resonant mode is represented by electric coupling, i.e., capacitive cross coupling is formed between the first resonant mode and the third resonant mode; the cross-coupling between the first and third resonant modes may create a transmission zero at the low end of the passband of the dielectric filter 200, while the hybrid coupling between the second and third resonant modes may create a transmission zero at the high end of the passband of the dielectric filter 200.

By performing simulation and actual product test on the dielectric filter 200 shown in fig. 13, an amplitude-frequency characteristic graph (i.e., an S-parameter characteristic simulation graph) of the dielectric filter 200 is obtained as shown in fig. 15. As can be seen from fig. 15, a transmission zero is generated on the left side (or low side) and the right side (or high side) of the passband of the dielectric filter 200, respectively, and the second harmonic is far from the passband, which shows that the dielectric filter 200 has better out-of-band rejection performance and anti-interference performance.

In fig. 16, a case where the dielectric filter 200 includes two three-mode dielectric resonators 1 is exemplarily shown, and dielectric bodies 10 of the two three-mode dielectric resonators 1 are connected to form the dielectric assembly 100 shown in fig. 11. By simulating the dielectric filter 200 shown in fig. 16, a amplitude-frequency characteristic graph is obtained as shown in fig. 17. As can be seen from fig. 17, two transmission zeros are generated on the left side (or low side) and the right side (or high side) of the passband of the dielectric filter 200 respectively, that is, four transmission zeros are formed in total, the two transmission zeros on the left side (or low side) of the passband are overlapped at 2.78GHz, the two transmission zeros on the right side (or high side) of the passband are overlapped at 3.78GHz, the out-of-band a21 parameter curve is very steep, the filter rectangular coefficient is very good, the near-end out-of-band interference signal can be effectively filtered, and the anti-interference performance is excellent.

The foregoing description of the preferred embodiments of the application is not intended to be limiting, but rather is intended to cover all modifications, equivalents, and alternatives falling within the spirit and principles of the application.

Claims

1. A three-mode dielectric resonator, characterized by: the three-mode dielectric resonator comprises a dielectric body, wherein a first resonance blind hole, a second resonance blind hole and a third resonance blind hole are respectively formed in the dielectric body, the first resonance blind hole, the second resonance blind hole and the third resonance blind hole are respectively used for forming a first resonance mode, a second resonance mode and a third resonance mode, and the first resonance mode, the second resonance mode and the third resonance mode are quasi-TEM modes;

The dielectric body is provided with a first hybrid coupling structure, and the first hybrid coupling structure is used for performing hybrid coupling between the second resonance mode and the third resonance mode to generate a transmission zero point.

2. The three-mode dielectric resonator of claim 1, wherein: the dielectric body is provided with a first plane, a second plane and a third plane, any two of the first plane, the second plane and the third plane are not parallel to each other, the first resonant blind hole is formed in the first plane, the second resonant blind hole is formed in the second plane, and the third resonant blind hole is formed in the third plane.

3. The three-mode dielectric resonator of claim 2, wherein: the first plane, the second plane and the third plane are perpendicular to each other; and/or

The depth direction of the first resonance blind hole, the depth direction of the second resonance blind hole and the depth direction of the third resonance blind hole are perpendicular to each other.

4. The three-mode dielectric resonator of claim 1, wherein the first hybrid coupling structure comprises:

the two ends of the first magnetic coupling groove are respectively communicated with the second resonance blind hole and the third resonance blind hole and are used for carrying out magnetic coupling between the second resonance mode and the third resonance mode; and

And the first electric coupling structure is positioned between the second resonance blind hole and the third resonance blind hole and is used for carrying out electric coupling between the second resonance mode and the third resonance mode.

5. The three-mode dielectric resonator of claim 4, wherein: the first magnetic coupling groove is of a blind groove structure formed in the surface of the dielectric body, and two ends of the first magnetic coupling groove are respectively communicated with the orifice of the second resonance blind hole and the orifice of the third resonance blind hole.

6. The three-mode dielectric resonator of claim 4, wherein: the first electric coupling structure is a blind groove structure and is communicated with the third resonance blind hole.

7. The three-mode dielectric resonator of claim 6, wherein: the depth direction of the first electric coupling structure is parallel to the depth direction of the third resonance blind hole; the first electric coupling structure is communicated with the first magnetic coupling groove, and the depth of the first electric coupling structure is larger than that of the first magnetic coupling groove;

the depth of the first electric coupling structure is greater than or equal to one half of the depth of the third resonance blind hole.

8. The three-mode dielectric resonator of claim 1, wherein: the first resonant mode, the second resonant mode and the third resonant mode are coupled to each other two by two, and cross coupling is formed between the first resonant mode and the third resonant mode to generate a transmission zero.

9. The three-mode dielectric resonator of claim 8, wherein: the dielectric body is provided with a second electric coupling structure, and the second electric coupling structure is positioned between the first resonance blind hole and the third resonance blind hole and is used for carrying out electric coupling between the first resonance mode and the third resonance mode to form cross coupling.

10. The three-mode dielectric resonator of claim 9, wherein the second electrical coupling structure comprises:

The first blind groove is formed in the surface of the dielectric body and is positioned between the first resonance blind hole and the third resonance blind hole; and

The second blind groove is formed in the bottom wall of the first blind groove;

wherein the first blind groove and the second blind groove form a stepped blind groove structure;

the three-mode dielectric resonator further comprises a first conductive layer and a second conductive layer, wherein the first conductive layer covers the outer surface of the dielectric body, the inner surface of the first resonance blind hole, the inner surface of the second resonance blind hole and the inner surface of the third resonance blind hole; the second conductive layer covers the inner surface of the second blind groove; the inner surface of the first blind groove is exposed so as to electrically insulate the second conductive layer from the first conductive layer.

11. The three-mode dielectric resonator according to any of claims 1 to 10, characterized in that: the dielectric body is provided with a second magnetic coupling groove, and two ends of the second magnetic coupling groove are respectively communicated with the first resonance blind hole and the second resonance blind hole and are used for carrying out magnetic coupling between the first resonance mode and the second resonance mode; and/or

And the dielectric body is provided with an electric coupling blocking structure, and the electric coupling blocking structure is positioned between the first resonance blind hole and the second resonance blind hole and used for blocking electric coupling between the first resonance mode and the second resonance mode.

12. The three-mode dielectric resonator of claim 11, wherein: the second magnetic coupling groove is of a blind groove structure formed in the surface of the dielectric body, and two ends of the second magnetic coupling groove are respectively communicated with the orifice of the first resonance blind hole and the orifice of the second resonance blind hole; and/or

The electric coupling blocking structure is a through groove penetrating through two opposite sides of the dielectric body.

13. The three-mode dielectric resonator of claim 1, wherein: the dielectric body is provided with a second hybrid coupling structure, and the second hybrid coupling structure is used for performing hybrid coupling between the first resonance mode and the second resonance mode to generate a transmission zero point.

14. The three-mode dielectric resonator according to any of claims 1 to 10, further comprising:

The dielectric body is provided with a second hybrid coupling structure, and the second hybrid coupling structure is used for performing hybrid coupling between the first resonance mode and the second resonance mode to generate a transmission zero point;

15. The three-mode dielectric resonator according to any of claims 1 to 10, further comprising:

16. A dielectric filter, characterized by: the dielectric filter comprising at least one three-mode dielectric resonator as claimed in any one of claims 1 to 15;

an input coupling hole is arranged on the dielectric body of one of the three-mode dielectric resonators, and is communicated with or capacitively coupled with one of the first resonance blind hole, the second resonance blind hole and the third resonance blind hole on the dielectric body for signal input;

The dielectric body of one of the three-mode dielectric resonators is provided with an output coupling hole, and the output coupling hole is communicated with or capacitively coupled with one of the first resonance blind hole, the second resonance blind hole and the third resonance blind hole on the dielectric body and is used for signal output.

17. The dielectric filter of claim 16, wherein: the dielectric filter further includes a metal film covering an opening of a slot or hole on at least one of the dielectric bodies.