CN212874715U

CN212874715U - Dielectric filter coupling structure, dielectric filter and communication base station

Info

Publication number: CN212874715U
Application number: CN202021183437.0U
Authority: CN
Inventors: 周国明
Original assignee: Anhui Tatfook Technology Co Ltd
Current assignee: Anhui Tatfook Technology Co Ltd
Priority date: 2020-06-23
Filing date: 2020-06-23
Publication date: 2021-04-02
Anticipated expiration: 2030-06-23

Abstract

The utility model relates to a dielectric filter coupled structure, dielectric filter and communication basic station, include the body of making by dielectric material and set up at this body surface at least a pair of dielectric resonator, be provided with the through-hole that passes through the body between a pair of dielectric resonator's first dielectric resonator and second dielectric resonator, first dielectric resonator and second dielectric resonator are located the upper surface and the lower surface of body respectively, and first coupling groove links to each other first dielectric resonator and through-hole, and the second coupling groove links to each other second dielectric resonator and through-hole, links to each other through coupling groove and through-hole between first dielectric resonator and the second dielectric resonator and realizes the capacitive coupling. The utility model discloses can realize stronger coupling bandwidth, can adapt to more extensive application scene.

Description

Dielectric filter coupling structure, dielectric filter and communication base station

Technical Field

The utility model relates to a communication equipment especially relates to dielectric filter cross coupling technique.

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 (hereinafter referred to as D1) discloses a dielectric filter, which realizes capacitive coupling by a deep blind via 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 that the low end of the filter pass band generates harmonic waves, which reduces the suppression capability of the filter.

CN210468050U (hereinafter referred to as D2) discloses a dielectric filter coupling structure for realizing symmetric transmission zeros, which includes two blind hole 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.

SUMMERY OF THE UTILITY MODEL

The to-be-solved technical problem of the utility model lies in, to the above-mentioned defect of prior art, propose one kind and can avoid producing parasitic resonance at wave filter resonant frequency low side, can improve the wave filter and restrain at the distal end of frequency low side to can avoid the space decay of electric field, increase the dielectric filter coupled structure, dielectric filter and the communication basic station of coupling volume.

The utility model provides a technical scheme that its technical problem adopted does:

the dielectric filter coupling structure comprises a body made of dielectric materials and at least one pair of dielectric resonators arranged on the surface of the body, wherein a through hole penetrating through the body is 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 first dielectric resonator is connected with the through hole through a first coupling groove, the second dielectric resonator is connected with the through hole through a second coupling groove, and the first dielectric resonator and the second dielectric resonator are connected through the coupling groove and the through hole to realize capacitive coupling.

Further:

the through hole is arranged in the center of the body.

The through hole is arranged at a position deviated from the center of the body, and the coupling amount is adjusted by adjusting at least one of the following parameters: coupling slot height, coupling slot width, coupling window size, or distance between dielectric resonators.

The through hole is cylindrical, and the first coupling groove and the second coupling groove are square columns.

The lower surface of the body is provided with a debugging blind hole corresponding to the first dielectric resonator on the upper surface of the body, and/or the upper surface of the body is provided with a debugging blind hole corresponding to the second resonator on the lower surface of the body, and the debugging blind hole and the dielectric resonator are coaxially arranged.

The debugging blind hole is circular, polygonal or oval.

And adjusting the frequency of the corresponding dielectric resonator by removing part of the conductive layer of the debugging blind hole.

The resonant frequency of the dielectric resonator is adjusted by removing a portion of the conductive layer of the dielectric resonator.

The depth of the coupling groove is smaller than that of the dielectric resonator.

There is provided a dielectric filter comprising a dielectric filter coupling structure as described in any one of the above.

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

Compared with the prior art, the utility model discloses following beneficial effect has:

the utility model discloses an among the capacitive cross coupling structure, a pair of dielectric resonator upper and lower surface sets up respectively, can let two magnetic field one around the dielectric resonator of upper surface, one around the dielectric resonator of lower surface, reverse setting can be drawn close the distance of its electric field to increase the capacitive coupling volume. And, the utility model discloses a coupling groove lug connection body changes a dielectric resonator magnetic field into surface current and directly transmits another dielectric resonator, compares with the mode that CN210468050U disclosed transmit another dielectric resonator again to the coupling groove through the space electric field coupling, can avoid the space decay of electric field, increases the coupling volume. Therefore, the utility model discloses can realize stronger coupling bandwidth, can adapt to more extensive application scene.

Drawings

Fig. 1 is a schematic perspective view of a coupling structure of a dielectric filter according to an embodiment of the present invention;

fig. 2 is a schematic shape diagram of an upper surface of an embodiment of a dielectric filter coupling structure according to the present invention;

fig. 3 is a schematic view of the shape of the lower surface of the coupling structure of the dielectric filter according to the embodiment of the present invention;

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

fig. 5 is a schematic perspective view of a zero-point embodiment of the cavity 4 of the dielectric filter 6 according to the present invention;

fig. 6 is a schematic diagram of the shape of the upper surface of a zero-point embodiment of the cavity 4 of the dielectric filter 6 according to the present invention;

fig. 7 is a schematic view of the shape of the lower surface of a zero-point embodiment of the cavity 4 of the dielectric filter 6 according to the present invention;

FIG. 8 is a schematic sectional view A-A of FIG. 6;

FIG. 9 is a schematic sectional view taken along line B-B of FIG. 6;

fig. 10 is a graph of the frequency response of an embodiment of the dielectric filter of the present invention;

figure 11 is a graph comparing the frequency response curve of an embodiment of the dielectric filter of the present invention with a prior art frequency response graph;

figure 12 is a graph comparing the frequency response curve of an embodiment of the dielectric filter of the present invention with another prior art coupling bandwidth.

Detailed Description

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

A dielectric filter coupling structure, as shown in FIGS. 1 to 4, includes a body 10 made of a dielectric material and dielectric resonators provided on a surface of the body 10, and a through-hole 13 passing through the body is provided between a first dielectric resonator 11 and a second dielectric resonator 12 of a 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. A first coupling groove 14 connects the first dielectric resonator 11 with the through hole 13, and a second coupling groove 15 connects the second dielectric resonator 12 with the through hole 13; the first dielectric resonator 11 and the second dielectric resonator 12 are connected through a coupling slot and a through hole to realize capacitive coupling. The two side surfaces of the body 10 are respectively provided with a coupling window 16. The strength of this capacitive coupling is controlled by the relative positions of the two dielectric resonators, the dimensions of the coupling slot, the via and the window. The surface of the body 10 including the two resonators, the two couplers and the through-hole is plated with a conductive layer. In practical engineering applications, the strength of the capacitive coupling is adjusted by removing part of the conductive layer of the coupling groove and the through hole, and specifically, the strength of the capacitive coupling can be adjusted by polishing the metallization layer (conductive layer) of the coupling groove and the through hole. The resonant frequency of the dielectric resonator is adjusted by removing part of the conductive layer of the dielectric resonator, and the resonant frequency can be adjusted by polishing the metallization layer of the blind hole of the resonator.

It is understood that in other embodiments, the coupling windows 16 are disposed on the same side of the body 10, and the number of the coupling windows 16 is not limited to 2, and may be provided in plurality as needed.

The magnetic field of the dielectric filter resonator surrounds the opening of the blind hole of the resonator, while the electric field is mainly concentrated at the bottom of the blind hole of the resonator, when the resonator is placed on the same surface, only the window is opened, the magnetic field coupling is strong, and the electric field coupling is weak. The utility model discloses a with the upper and lower surface setting of a pair of syntonizer of capacitive cross coupling structure, can let a syntonizer that encircles the upper surface in two magnetic fields, a syntonizer that encircles the lower surface. The utility model discloses the upper and lower surface setting of a pair of syntonizer can be drawn close the distance of electric field to increase the capacitive coupling volume. And when the upper and lower surfaces of a pair of resonators are arranged, the coupling grooves are directly connected with the resonators, the magnetic field at the opening of the blind hole of the resonator is converted into surface current to be directly transmitted to another resonator, and compared with the mode that the magnetic field is coupled to the coupling grooves through the space electric field and then transmitted to another dielectric resonator, the method disclosed by D2 can avoid the space attenuation of the electric field and increase the coupling amount. Therefore, the utility model discloses can realize stronger coupling bandwidth, can adapt to more extensive application scene.

And, compare with current frequency conversion structure, the utility model discloses self harmonic peak is far above basic mode frequency, and the outband performance is more excellent. The crosstalk is small and no parasitic coupling exists. Compared with a capacitive coupling structure derived from a traditional cavity filter flying rod structure, the coupling structure in the technical scheme has the advantages of simple implementation mode, easiness in processing and convenience for mass production.

In some embodiments, the through hole 13 is provided in the center of the body. In other embodiments, the through hole 13 may be disposed at a position offset from the center of the body, for example, in an actual product, the through hole may be required to be offset to one side. The off-center affects the frequency of a side and the amount of coupling is reduced accordingly, which allows the amount of coupling to be adjusted appropriately. The coupling amount can be adjusted by adjusting the height of the coupling slot, the size of the window and the distance between the two resonators. The first coupling groove and the second coupling groove are square columns, and the through hole is preferably cylindrical and can be in other shapes.

The lower surface of the body is provided with a debugging blind hole for assisting in fine tuning the frequency of the dielectric resonator corresponding to the first dielectric resonator on the upper surface of the body, and/or the upper surface of the body is provided with a debugging blind hole for assisting in fine tuning the frequency of the dielectric resonator corresponding to the second dielectric resonator on the lower surface of the body, and the debugging blind hole and the dielectric resonator are coaxially arranged. 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 is realized by polishing the conducting layer such as a silver layer on the surface part of the debugging blind hole.

The dielectric filter coupling structure can be applied to a dielectric filter.

The technical solution of the present invention will be described in detail below by taking an example of applying the above coupling structure to a 6-cavity 4-transmission zero dielectric filter.

As shown in fig. 5 to 9, the dielectric filter in this embodiment is a dielectric body with a whole outer layer plated with silver, the dielectric body is provided with 6 dielectric resonators with the number of 101-. The capacitive coupling structure of the present embodiment is disposed between the

dielectric resonators

101 and 104, and includes a through hole 201, a first coupling groove 301, and a second coupling groove 302. Other couplings of this embodiment are inductive couplings, implemented through a dielectric coupling window between the two resonators.

In the 6 dielectric resonators described in this embodiment, the 104 dielectric resonators and the other 5 dielectric resonators are disposed in opposite directions. The opposite side of the dielectric resonator 104 is provided with a fine tuning hole 501, and the fine tuning of the silver layer of the hole can be achieved through polishing 501. The debugging hole in the technical scheme can be in a special-shaped structure such as a circle, a polygon, an ellipse and the like. In this technical solution, the debugging hole is preferably cylindrical, the coupling groove is preferably square column shaped, and the through hole is preferably cylindrical, and may be in other shapes.

The tap cavities in this embodiment are disposed in the

dielectric resonators

101 and 106, and when a signal is transmitted from the input port to the dielectric resonator 101, the signal is coupled into the dielectric resonator 104 through the capacitive coupling, the dielectric resonator 103 is inductively coupled into the dielectric resonator 104, the inductive coupling quantity and the capacitive coupling quantity meet each other, and the phase difference thereof is 180 ° to form two transmission zeros; the signal is capacitively coupled into the dielectric resonator 104 by the dielectric resonator 101, is inductively coupled into the dielectric resonator 104 by the dielectric resonator 105, and the inductive coupling quantity meets the capacitive coupling quantity, so that two transmission zero points can be added, and 4 transmission zero points are realized in total, thereby realizing the requirement of strong suppression index.

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

The utility model discloses the frequency response curve of dielectric filter embodiment is shown in figure 10, and this structure embodiment frequency response graph passband left side and right side respectively produce two transmission zero points, have strengthened outband and have restrained, and do not have extra harmonic at the passband low side and produce, can satisfy product property ability demand better.

The utility model discloses the frequency response curve of dielectric filter embodiment and the frequency response curve pair of the disclosed scheme of D1 for example as shown in FIG. 11, curve 1 is the utility model discloses the frequency response curve of scheme, curve 2 are the frequency response curve of the disclosed scheme of D1, and very obviously can see, and curve 2 produces the formant at the wave filter passband low side, and curve 1 passband low side does not have extra harmonic to produce, consequently, the utility model discloses the relative disclosed scheme of D1 of scheme, it is effectual to restrain.

The utility model discloses the frequency response curve of dielectric filter embodiment and the coupling bandwidth of the disclosed scheme of D2 are to for example as shown in FIG. 12, and in the figure, the ordinate represents the coupling bandwidth, and the abscissa represents the coupling groove height, and curve 1 is the utility model discloses the coupling bandwidth curve of scheme, curve 2 are the coupling bandwidth curve of the disclosed scheme of D2. It is obvious that, under the same structural size, the coupling bandwidth of the scheme of the invention is at least 25% more than that of the scheme disclosed by D2. Therefore, the utility model discloses the scheme can realize wideer coupling relative to the disclosed scheme of D2, has more extensive application scenario.

In addition, compared with the traditional capacitive coupling structure form, the capacitive coupling structure scheme can simply and flexibly realize the coupling bandwidth without introducing extra parts and procedures, 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.

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 that such modifications and substitutions are intended to be included within the scope of the appended claims.

Claims

1. A dielectric filter coupling structure comprising a body made of a dielectric material and at least one pair of dielectric resonators provided on a surface of the body, a through-hole passing through the body 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 first coupling groove connects the first dielectric resonator with the through hole, the second coupling groove connects the second dielectric resonator with the through hole, and the first dielectric resonator and the second dielectric resonator are connected through the coupling groove and the through hole to realize capacitive coupling.

2. A dielectric filter coupling structure according to claim 1, wherein: the through hole is arranged in the center of the body.

3. A dielectric filter coupling structure according to claim 1, wherein: the through hole is arranged at a position deviated from the center of the body, and the coupling amount is adjusted by adjusting at least one of the following parameters: coupling slot height, coupling slot width, coupling window size, or distance between dielectric resonators.

4. A dielectric filter coupling structure according to claim 1, wherein: the through hole is cylindrical, and the first coupling groove and the second coupling groove are square columns.

5. A dielectric filter coupling structure according to claim 1, wherein: the lower surface of the body is provided with a debugging blind hole corresponding to the first dielectric resonator on the upper surface of the body, and/or the upper surface of the body is provided with a debugging blind hole corresponding to the second resonator on the lower surface of the body, and the debugging blind hole and the dielectric resonator are coaxially arranged.

6. The dielectric filter coupling structure of claim 5, wherein: the debugging blind hole is circular, polygonal or oval.

7. The dielectric filter coupling structure of claim 5, wherein: and adjusting the frequency of the corresponding dielectric resonator by removing part of the conductive layer of the debugging blind hole.

8. A dielectric filter coupling structure according to claim 1, wherein: the depth of the coupling groove is smaller than that of the dielectric resonator.

9. A dielectric filter, characterized by: comprising a dielectric filter coupling structure according to any of claims 1 to 8.

10. A communication base station, characterized by: comprising a dielectric filter coupling structure according to any of claims 1 to 8.