阅读说明：本技术 介质滤波器及通信基站 (Dielectric filter and communication base station ) 是由 吴亚晖 钟志波 于 2020-06-23 设计创作，主要内容包括：本发明涉及一种介质滤波器和通信基站,包括由介电材料制成的本体和设置在该本体表面的至少一对介质谐振器,在一对介质谐振器的第一介质谐振器和第二介质谐振器之间设置有两个耦合槽,所述第一介质谐振器和第二介质谐振器分别位于本体的上表面和下表面,两个耦合槽分别位于本体的上表面和下表面,两个耦合槽至少部分连通,第一介质谐振器和第二介质谐振器之间通过耦合槽实现容性耦合。本发明具有可简单、灵活实现耦合带宽,且无谐波产生和便于大批量生产的技术效果。(The invention relates to a dielectric filter and a communication base station, which comprise a body made of dielectric materials and at least one pair of dielectric resonators arranged on the surface of the body, wherein two coupling grooves are arranged between a first dielectric resonator and a second dielectric resonator of the pair of dielectric resonators, the first dielectric resonator and the second dielectric resonator are respectively positioned on the upper surface and the lower surface of the body, the two coupling grooves are at least partially communicated, and the first dielectric resonator and the second dielectric resonator are capacitively coupled through the coupling grooves. The invention has the technical effects of simple and flexible realization of coupling bandwidth, no harmonic generation and convenient mass production.)

1. A dielectric filter comprising a body made of a dielectric material and at least one pair of dielectric resonators provided on a surface of the body, two coupling grooves being provided between a first dielectric resonator and a second dielectric resonator of the pair of dielectric resonators, characterized in that: the first dielectric resonator and the second dielectric resonator are respectively positioned on the upper surface and the lower surface of the body, the two coupling grooves are at least partially communicated, and capacitive coupling is realized between the first dielectric resonator and the second dielectric resonator through the coupling grooves.

2. A dielectric filter as recited in claim 1, wherein: the first coupling groove includes a communicating portion and an extending portion extending toward the second dielectric resonator, and the second coupling groove includes a communicating portion and an extending portion extending toward the first dielectric resonator.

3. A dielectric filter as recited in claim 2, wherein: the extension part of the first coupling groove extends to the right upper part of the second dielectric resonator, and the extension part of the second coupling groove extends to the right lower part of the first dielectric resonator.

4. A dielectric filter as recited in claim 2, wherein: the communication part of the first coupling groove is positioned at the center of the upper surface of the body, and the communication part of the second coupling groove is positioned at the center of the lower surface of the body.

5. A dielectric filter as recited in claim 2, wherein: the extension part of the first coupling groove and the extension part of the second coupling groove are both arc-shaped.

6. A dielectric filter as recited in claim 1, wherein: and a debugging blind hole for assisting in fine tuning the frequency of the dielectric resonator is coaxially arranged on the surface of the body opposite to the dielectric resonator.

7. The dielectric filter of claim 5, wherein: the debugging blind hole is circular, polygonal or oval, and the surface part of the debugging blind hole is not covered by the conducting layer.

8. A dielectric filter comprising a body made of a dielectric material and dielectric resonators provided on the body, characterized in that: the four dielectric resonators are respectively positioned at four corners of a quadrangle, and a capacitive coupling structure is arranged between each two adjacent dielectric resonators; the first dielectric resonator and the second dielectric resonator of the pair of dielectric resonators are respectively located on the upper surface and the lower surface of the body, the two coupling grooves are respectively located on the upper surface of the body and the lower surface of the body, the two coupling grooves are at least partially communicated, and capacitive coupling is achieved between the first dielectric resonator and the second dielectric resonator through the coupling grooves.

9. A dielectric filter as recited in claim 8, wherein: the first coupling groove and the second coupling groove respectively comprise a communicating part and an extending part, the communicating parts of the first coupling groove and the second coupling groove are cylindrical, and the extending parts are arc-shaped.

10. A communication base station, characterized by: comprising a dielectric filter according to any of claims 1 to 9.

Technical Field

The invention relates to communication equipment, in particular to a cross coupling technology of a dielectric filter.

Background

Along with the construction of a 5G communication system, the requirement of equipment on the integration level is higher and higher, the miniaturization and the light weight of the microwave filter are the future application trend, and the dielectric waveguide has the advantages of high Q value, small temperature drift and the like, so that the microwave filter is a good miniaturization solution of the filter.

The dielectric filter usually needs to introduce capacitive cross coupling to achieve the effect of strong suppression of transmission zero, and a capacitive coupling structure (a single high-end transmission zero does not need to be introduced at times) needs to be introduced to achieve low-end transmission zero and symmetric transmission zero, and the capacitive coupling achieved by the conventional dielectric waveguide filter usually takes the following forms: firstly, a frequency-variable coupling structure is adopted, and although the structure is simple, an additional resonance point is introduced. And secondly, a capacitive coupling structure directly derived from a traditional cavity filter flying rod structure is relatively complex, and parts and processes of a product are increased.

CN 108598635 a discloses a dielectric filter, which realizes capacitive coupling by a deep blind hole with a depth exceeding one-half of the body, and this scheme simplifies the manufacturing process for realizing the capacitive coupling structure, but has the disadvantage of generating harmonics at the low end of the filter passband, reducing the rejection capability of the filter.

CN210468050U discloses a dielectric filter coupling structure for realizing symmetric transmission zeros, which includes two blind resonators located on the same surface, a first blind slot located below the body, and a second blind slot located above the body. The first blind groove extends towards one blind hole resonator, the second blind groove extends towards the other blind hole resonator, and the first blind groove and the second blind groove are connected with the through hole penetrating through the body. The scheme can not generate extra resonance outside the passband of the filter, and can improve the out-of-band rejection capability of the filter. However, the two resonators are located on the same surface, the magnetic field coupling is strong, the electric field coupling is weak, and the application scene is narrow.

Disclosure of Invention

The present invention is directed to overcome the above-mentioned drawbacks of the prior art, and a dielectric filter capable of avoiding the generation of parasitic resonance at the low end of the resonant frequency of the filter and improving the far-end rejection of the filter at the low end of the frequency is provided.

The technical scheme adopted by the invention for solving the technical problems is as follows:

the dielectric filter comprises a body made of dielectric materials and at least one pair of dielectric resonators arranged on the surface of the body, wherein two coupling grooves are formed between a first dielectric resonator and a second dielectric resonator of the pair of dielectric resonators, the first dielectric resonator and the second dielectric resonator are respectively positioned on the upper surface and the lower surface of the body, the two coupling grooves are at least partially communicated, and capacitive coupling is realized between the first dielectric resonator and the second dielectric resonator through the coupling grooves.

Further:

the first coupling groove includes a communicating portion and an extending portion extending toward the second dielectric resonator, and the second coupling groove includes a communicating portion and an extending portion extending toward the first dielectric resonator.

The extension part of the first coupling groove extends to the right upper part of the second dielectric resonator, and the extension part of the second coupling groove extends to the right lower part of the first dielectric resonator.

The communication part of the first coupling groove is positioned at the center of the upper surface of the body, and the communication part of the second coupling groove is positioned at the center of the lower surface of the body.

The extension part of the first coupling groove and the extension part of the second coupling groove are both arc-shaped.

And a debugging blind hole for assisting in fine tuning the frequency of the dielectric resonator is coaxially arranged on the surface of the body opposite to the dielectric resonator.

The debugging blind hole is circular, polygonal or oval, and the surface part of the debugging blind hole is not covered by the conducting layer.

The dielectric filter comprises a body made of dielectric materials and dielectric resonators arranged on the body, wherein four dielectric resonators are arranged at four corners of a quadrangle respectively, and a capacitive coupling structure is arranged between each two adjacent dielectric resonators; the first dielectric resonator and the second dielectric resonator of the pair of dielectric resonators are respectively located on the upper surface and the lower surface of the body, the two coupling grooves are respectively located on the upper surface of the body and the lower surface of the body, the two coupling grooves are at least partially communicated, and capacitive coupling is achieved between the first dielectric resonator and the second dielectric resonator through the coupling grooves.

There is provided a communications base station comprising a dielectric filter as claimed in any preceding claim.

Compared with the existing capacitive coupling structure, the capacitive coupling structure scheme has the advantages that the upper surface and the lower surface of the dielectric resonators are respectively arranged, so that the two magnetic fields, namely the dielectric resonator surrounding the upper surface and the dielectric resonator surrounding the lower surface, are reversely arranged to be capable of shortening the distance of the electric fields, and the capacitive coupling amount is increased. And additional parts and processes are not required to be introduced, the coupling bandwidth can be simply and flexibly realized, and no harmonic wave is generated, so that the performance and the design flexibility of the product are guaranteed, the production difficulty is reduced, and the mass production is facilitated.

Drawings

FIG. 1 is a schematic perspective view of one embodiment of a dielectric filter according to the present invention;

FIG. 2 is a schematic top surface view of one embodiment of a dielectric filter according to the present invention;

FIG. 3 is a schematic diagram of the bottom surface structure of one embodiment of the dielectric filter of the present invention;

FIG. 4 is a schematic sectional view A-A of FIG. 2;

fig. 5 is a schematic top surface structure of another embodiment of the dielectric filter of the present invention;

fig. 6 is a schematic view of the lower surface structure of another embodiment of the dielectric filter of the present invention;

FIG. 7 is a schematic sectional view A-A of FIG. 5;

fig. 8 is a schematic diagram of the upper surface structure of an embodiment of the transmission zero of the cavity 2 of the dielectric filter 4 according to the invention;

fig. 9 is a schematic view of the lower surface structure of an embodiment of the transmission zero of the cavity 2 of the dielectric filter 4 according to the present invention;

FIG. 10 is a topological block diagram of capacitive coupling and inductive coupling in accordance with an embodiment of the present invention;

FIG. 11 is a graph of the passband near end frequency response of an embodiment of a dielectric filter of the present invention;

figure 12 is a plot of the passband distal frequency response of an embodiment of a dielectric filter of the present invention.

Detailed Description

The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

A dielectric filter, as shown in FIGS. 1 to 4, includes a body 10 made of a dielectric material and at least one pair of dielectric resonators provided on a surface of the body 10, a coupling window 16 and two coupling grooves being provided between a first dielectric resonator 11 and a second dielectric resonator 12 of the pair of dielectric resonators. The first dielectric resonator 11 and the second dielectric resonator 12 are respectively located on the upper surface and the lower surface of the body 10, the first coupling groove 13 is respectively located on the upper surface of the body, the second coupling groove 14 is located on the lower surface of the body, the first coupling groove 13 and the second coupling groove 14 are at least partially communicated, and capacitive coupling is achieved between the first dielectric resonator 11 and the second dielectric resonator 12 through the coupling grooves. The strength of the capacitive coupling is adjusted by removing parts of the conductive layer of the coupling slot and the coupling window. The resonant frequency of the dielectric resonator is adjusted by removing part of the conductive layer on the surface of the dielectric resonator.

The first coupling groove 13 includes a communicating portion and an extending portion extending toward the second dielectric resonator 12, and the second coupling groove 14 includes a communicating portion and an extending portion extending toward the first dielectric resonator 11. The extension part of the first coupling groove extends to the right upper part of the second dielectric resonator, and the extension part of the second coupling groove extends to the right lower part of the first dielectric resonator. Because the strongest part of the electric field of the dielectric resonator is near the bottom of the blind hole of the resonator and the strongest part of the magnetic field is near the hole opening of the blind hole of the resonator, the method can increase the distance between the coupling groove and the hole opening of the dielectric resonator positioned on the same surface, thereby reducing the electromagnetic coupling between the first coupling groove and the first resonator and further reducing the weakening effect of the electromagnetic coupling on the electric field coupling.

The communicating portion may be cylindrical, square, U-shaped, etc., and the extending portion may be arc-shaped, elongated, U-shaped, etc. As shown in fig. 5 to 7, the communication portion of the coupling groove is cylindrical and the extension portion is arc-shaped. This has the advantage that more of the electric field can be directed from one dielectric resonator to the other, thereby enhancing the capacitive coupling between the resonators. Therefore, the structure shown in fig. 2 can increase the distance between the coupling slot and the resonator while maintaining the same coupling strength, thereby facilitating the processing and forming of the dielectric.

As shown in fig. 5 and 7, a tuning blind hole 15 for assisting in trimming the frequency of the dielectric resonator is provided coaxially with the dielectric resonator on the surface of the body 10 opposite to the dielectric resonator. In this embodiment, a tuning blind hole 15 for assisting in trimming the frequency of the dielectric resonator is provided coaxially with the second dielectric resonator 12 on the upper surface of the body. The debugging blind hole is circular, polygonal or oval. The surface part of the debugging blind hole is not covered by the conducting layer, and the debugging blind hole is realized by removing part of the conducting layer, such as a silver layer, on the surface of the debugging blind hole.

The dielectric filter can be applied to a wireless communication base station.

The following is a 4-cavity 2 transmission zero dielectric filter to explain the technical scheme of the invention in detail.

As shown in fig. 8 and 9, the whole outer layer of the body 10 of the dielectric filter in this embodiment is plated with silver, 4 dielectric resonators are disposed on the body, coupling windows are disposed between every two dielectric resonators, and a capacitive coupling structure and an inductive coupling structure are disposed in corresponding open coupling windows. The capacitive coupling structure of the present embodiment is provided between the dielectric resonator 2 and the dielectric resonator 3, the dielectric resonator 2 and the dielectric resonator 3 being respectively located on the upper surface and the lower surface of the body, and includes coupling grooves 7 respectively located on the upper surface coupling groove 6 and the lower surface of the body. The first coupling groove and the second coupling groove both comprise a communicating part and an extending part, in the embodiment, the communicating part of the first coupling groove and the second coupling groove is similar to a cylinder, and the extending part is arc-shaped.

In this embodiment, except for capacitive coupling between the dielectric resonator 2 and the dielectric resonator 3, other couplings are inductive couplings, and are realized through a dielectric coupling window between the two resonators, such as a topological structure shown in fig. 4. The debugging blind holes of the dielectric resonator 1, the dielectric resonator 2 and the dielectric resonator 4 are positioned on the back surface of the body. The tuning blind hole 5 of the resonator 3 is located on the front side of the body, and the tuning blind hole is a shallow hole for fine tuning the frequency of the resonator 3. The frequency of the resonator is realized by removing the silver layer on the surface of the dielectric resonator, and the coupling adjustment is realized by removing the conductive layers of the coupling window and the coupling groove structure. The debugging blind hole in the technical scheme can be in a special-shaped structure such as a circle, a polygon and an ellipse.

The dielectric filter topology in this embodiment is shown in fig. 10, and a total of 2 transmission zeros are implemented, so as to implement the requirement of the near-end strong suppression index, as shown in fig. 11. Fig. 12 shows far-end rejection and parasitic resonance conditions of the filter, and the invention has no parasitic resonance at the low end of the filter passband and good far-end rejection at the low end of the passband. Parasitic resonance is generated at the high end of the passband and is close to the higher-order mode resonance frequency of the resonator, so that the high end of the passband of the filter still has good far-end suppression.

The capacitive coupling structure in the technical scheme has the advantages of simple implementation mode, easiness in processing and convenience for mass production.

It should be understood that the above embodiments are only used for illustrating the technical solutions of the present invention, and not for limiting the same, and those skilled in the art can modify the technical solutions described in the above embodiments, or make equivalent substitutions for some technical features; and such modifications and substitutions are intended to be included within the scope of the appended claims.