CN109687072B

CN109687072B - Filter with a filter element having a plurality of filter elements

Info

Publication number: CN109687072B
Application number: CN201910027304.XA
Authority: CN
Inventors: 陈荣达; 谢懿非; 欧阳洲
Original assignee: Suzhou Rf Top Electronic Communications Co ltd
Current assignee: SUZHOU RF TOP ELECTRONIC COMMUNICATIONS Co.,Ltd.
Priority date: 2019-01-11
Filing date: 2019-01-11
Publication date: 2020-04-21
Anticipated expiration: 2039-01-11
Also published as: CN109687072A; WO2020143070A1

Abstract

The present invention provides a filter, comprising: the ceramic comprises a ceramic body and metal layers arranged on the inner surface and the outer surface of the ceramic body; one side of the ceramic body is provided with a plurality of resonant cavities, a hole which is used for being in capacitive coupling and penetrates through the ceramic body is arranged between two resonant cavities in the plurality of resonant cavities, an annular adjusting band is arranged on the upper end edge and/or the lower end edge of the hole, a metal layer is not arranged on the adjusting band, the length h1 of the hole defines a first performance parameter of the filter, the aperture D1 of the hole defines a second performance parameter of the filter, and the adjusting band is defined by an annular groove on an annular region exposed on the upper end edge and/or the lower end edge of the hole. The filter realizes the capacitive coupling performance of the filter by arranging the holes between the resonant cavities, and effectively adjusts the capacitive coupling size, out-of-band inhibition, far-end inhibition and other performances of the filter by manufacturing the adjusting band on the holes, and particularly can greatly improve the zero balance of two sides of the pass band of the filter.

Description

Filter with a filter element having a plurality of filter elements

Technical Field

The invention relates to the technical field of communication, in particular to a filter applied to the field of communication.

Background

The dielectric waveguide filter is a microwave filter which adopts a dielectric resonant cavity to obtain the frequency-selecting function through multi-stage coupling. The surface of the dielectric waveguide filter is covered with a metal layer, and the electromagnetic wave is confined in the medium to form standing wave oscillation. The main advantages of the dielectric waveguide filter are large power capacity and low insertion loss, but the existing dielectric filter has quite difficult capacitive coupling and has stray influence on the left far end and the right far end, thus limiting the application of the dielectric filter. Therefore, it is necessary to provide a further solution to the above-mentioned requirements.

Disclosure of Invention

The present invention is directed to a filter that overcomes the deficiencies of the prior art.

In order to solve the technical problems, the technical scheme of the invention is as follows:

a filter, comprising: the ceramic comprises a ceramic body and metal layers arranged on the inner surface and the outer surface of the ceramic body;

the filter comprises a ceramic body and is characterized in that a plurality of resonant cavities are arranged on one surface of the ceramic body, a hole which is used for capacitive coupling and penetrates through the ceramic body is arranged between two resonant cavities in the plurality of resonant cavities, an annular adjusting band is arranged on the upper end edge and/or the lower end edge of the hole, the metal layer is not arranged on the adjusting band, the length h1 of the hole defines a first performance parameter of the filter, the aperture D1 of the hole defines a second performance parameter of the filter, and the adjusting band is defined by an annular groove on an annular region exposed on the upper end edge and/or the lower end edge of the hole.

As an improvement of the filter, the hole is positioned at the midpoint of a connecting line between the two resonant cavities.

As an improvement of the filter of the present invention, the cross-sectional shape of the hole is: one of circular, elliptical, polygonal, or irregular.

As an improvement of the filter of the invention, the depth h2 of the annular groove defines a third performance parameter of the filter, and the diameter D2 of the annular groove defines a fourth performance parameter of the filter.

As an improvement of the filter, the number of the resonant cavities is six, and the six resonant cavities are arranged on one surface of the ceramic body in an array form.

As an improvement of the filter, the resonant cavities in two adjacent columns of the three columns of resonant cavities are isolated by the first isolation cavity, and the resonant cavities in the two adjacent columns are isolated from the resonant cavities in the other column by the second isolation cavity.

As an improvement of the filter of the present invention, the hole is located between two resonators in the remaining column.

As an improvement of the filter of the present invention, the metal layer is a silver plated layer or a copper plated layer.

Compared with the prior art, the invention has the beneficial effects that: the filter realizes the capacitive coupling performance of the filter by arranging the holes between the resonant cavities, and effectively adjusts the capacitive coupling size, out-of-band rejection, far-end rejection and other performances of the filter by manufacturing the adjusting band on the holes, particularly can greatly improve the zero balance of two sides of the pass band of the filter, and fully meets the actual use requirements. In addition, the filter is easier to machine and die-cast and is simpler in process and more beneficial to production in terms of physical structure.

Drawings

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

FIG. 1 is a top view of a filter of the present invention;

FIG. 2 is a bottom view of the filter of the present invention;

FIG. 3 is an enlarged cross-sectional view taken along line A-A of FIG. 1 in accordance with another embodiment, wherein the adjustment band is an annular region disposed at the upper and lower edges of the hole;

FIG. 4 is an enlarged cross-sectional view taken along the line A-A of FIG. 1 in accordance with another embodiment, wherein the adjustment band is an annular groove formed in the upper and lower edges of the hole;

FIG. 5 is a graph of the S-parameter of the filter of the present invention;

note that the a-a direction is a direction perpendicular to the paper surface, and is drawn obliquely for convenience of drawing.

Detailed Description

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

As shown in fig. 1 and 2, the present invention provides a filter, which includes: the ceramic body 1, set up in the metal level 2 of the internal and external surface of ceramic body 1.

One side of the ceramic body 1 is provided with a plurality of resonant cavities 11, the resonant cavities 11 are blind holes arranged on one side of the ceramic body 1, and the resonant cavities 11 realize frequency-selective filtering through multi-stage coupling. Since the filtering of the filter is in principle prior art, it will not be described in detail here.

In one embodiment, the number of the resonant cavities 11 is six, and in this case, the six resonant cavities 11 are arranged in an array on one surface of the ceramic body 1. In this embodiment, the resonant cavities 11 in two adjacent columns of the three columns of resonant cavities 11 are isolated from each other by the first isolation cavity 12. The first isolation cavity 12 is a cross-shaped structure, and four resonant cavities 11 are respectively distributed in four areas divided by the first isolation cavity 12. Each resonant cavity 11 of the two adjacent columns is separated from the resonant cavities 11 of the other columns by a second separation cavity 13. The second segregation chamber 13 is substantially T-shaped.

As shown in fig. 3 and 4, a hole 14 for capacitive coupling penetrating through the ceramic body 1 is disposed between two resonant cavities 11 of the plurality of resonant cavities 11, and the hole 14 has an advantage of being convenient to process compared with a blind hole while achieving capacitive coupling. Because, when the blind hole is opened, the distance between the bottom of the blind hole and the surface of the ceramic body 1 has the precision requirement, the precision requirement obviously improves the process difficulty and the cost of the device, and the problem is overcome by opening the through hole. Preferably, the hole 14 is located at the midpoint of the line connecting the two resonant cavities 11. When the number of the resonant cavities 11 is six and the resonant cavities are arranged in an array, the holes 14 are located between two resonant cavities 11 in the other column. In addition, the cross-sectional shape of the hole 14 may be: one of circular, elliptical, polygonal, or irregular. Preferably, the cross-sectional shape of the hole 14 is circular.

In order to realize the adjustment of the capacitive coupling, out-of-band suppression, far-end suppression, and the like, the upper end edge and/or the lower end edge of the hole 14 is/are provided with an annular adjusting band 141, and the metal layer 2 is not arranged at the position of the adjusting band 141. When the adjustment bands 141 are provided at both the upper and lower end edges of the hole 14, there is a better capacitive coupling effect than when the adjustment bands 141 are provided at one end edge.

The length h1 of the hole 14 defines a first performance parameter of the filter and the aperture D1 of the hole 14 defines a second performance parameter of the filter.

Therefore, by changing the distance h1 between the adjusting band 141 and one surface of the ceramic body 1 or the size parameter of the aperture D1 of the hole 14, the performance such as the capacitive coupling size, out-of-band rejection, far-end rejection and the like can be adaptively adjusted, so that the filter provided by the invention meets the use requirements under corresponding conditions.

In order to verify the correlation between the first and second performance parameters and the performance of the capacitive coupling, out-of-band rejection, far-end rejection, etc., as shown in fig. 5, a graph of the S-parameters characterizing the performance of the filter of the present invention at different frequencies is established, wherein the S-parameters are scattering parameters. Is an important parameter in microwave transmission.

As can be seen from fig. 5, a point a peak and a point B peak distributed left and right appear in the L curve, which indicates that the filter of the present invention has capacitive coupling performance, and the difference in height between the point a peak and the point B peak reflects the influence on out-of-band rejection. In addition, a C point peak is also generated in the L curve, and the C point peak is the far-end harmonic wave, compared with the similar capacitive coupling, the harmonic wave point of the invention is farther away from the passband, and the suppression degree is larger, thereby showing that the filter of the invention can generate far-end suppression with better characteristics.

As shown again in fig. 3, in another alternative embodiment, the upper and lower edges of the hole 14 are provided with annular adjustment bands 141. The adjusting band 141 is defined by annular areas where the upper and lower end edges of the hole 14 are exposed. In the present embodiment, the processing manner of the adjustment belt 141 is also processed by a milling cutter, and the description thereof is not repeated.

As shown again in fig. 4, in another alternative embodiment, the upper and lower end edges of the hole 14 are provided with annular adjustment bands 141. The adjustment band 141 is defined by an annular groove in the annular region where the upper and lower end edges of the hole 14 are exposed. In the present embodiment, the adjustment band 141 is also formed by milling. During processing, the milling cutter is controlled to mill the metal layer 2 corresponding to the surface of the adjusting belt 141 firstly, and then milling is continued, so that an annular groove structure is formed in the exposed annular area, the annular groove structure occupies part or all of the exposed annular area, and a step structure is formed between the exposed annular area and the annular groove structure when the annular groove structure occupies part of the exposed annular area. At this time, by adjusting the height of the step structure, the adjustment of the capacitive coupling magnitude can also be achieved.

In the above alternative embodiment, the third performance parameter of the filter is defined by forming the groove structure in a ring shape such that the depth h2 of the ring groove defines the third performance parameter of the filter, and the diameter D2 of the ring groove defines the fourth performance parameter of the filter. Therefore, the first, second, third and fourth performance parameters can adjust and optimize the performance of the filter together.

The other side of the ceramic body 1 is also provided with an input port 15 and an input port 16.

The metal layer 2 is used for realizing the electrical performance of the filter of the present invention, and preferably, the metal layer 2 may be a silver plating layer or a copper plating layer. Furthermore, the metal layer 2 can also be replaced by other layer structures having electrically conductive properties.

In summary, the filter of the present invention realizes the capacitive coupling performance of the filter by forming the holes between the resonant cavities, and at the same time, by fabricating the adjustment bands on the holes, the filter effectively adjusts the capacitive coupling size, out-of-band rejection, far-end rejection, and other properties of the filter, and particularly, the filter can greatly improve the zero balance at both sides of the pass band of the filter, thereby fully satisfying the actual use requirements. In addition, the filter is easier to machine and die-cast and is simpler in process and more beneficial to production in terms of physical structure.

It will be evident to those skilled in the art that the invention is not limited to the details of the foregoing illustrative embodiments, and that the present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. Any reference sign in a claim should not be construed as limiting the claim concerned.

Furthermore, it should be understood that although the present description refers to embodiments, not every embodiment may contain only a single embodiment, and such description is for clarity only, and those skilled in the art should integrate the description, and the embodiments may be combined as appropriate to form other embodiments understood by those skilled in the art.

Claims

1. A filter, characterized in that the filter comprises: the ceramic comprises a ceramic body and metal layers arranged on the inner surface and the outer surface of the ceramic body;

2. A filter according to claim 1, wherein the hole is located at the midpoint of a line connecting the two resonators.

3. The filter of claim 1, wherein the cross-sectional shape of the holes is: one of circular, elliptical, polygonal, or irregular.

4. The filter of claim 1, wherein a depth h2 of the annular groove defines a third performance parameter of the filter, and a diameter D2 of the annular groove defines a fourth performance parameter of the filter.

5. The filter of claim 1, wherein the number of resonant cavities is six, and the six resonant cavities are arranged in an array on one face of the ceramic body.

6. A filter according to claim 5, wherein the resonant cavities of two adjacent columns of the three columns of resonant cavities are separated by a first separation cavity, and the resonant cavities of the two adjacent columns are separated from the resonant cavities of the other columns by a second separation cavity.

7. A filter according to claim 6, characterised in that the hole is located between two resonators in the remaining column.

8. The filter of claim 1, wherein the metal layer is a silver or copper plated layer.