CN109546270B - Filter - Google Patents

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; 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 formed between two resonant cavities in the plurality of resonant cavities, an annular coupling band is arranged on the hole wall of the hole, the metal layer is not arranged on the coupling band, the width h1 of the coupling band defines a first performance parameter of the filter, the distance h2 between the coupling band and one surface of the ceramic body defines a second performance parameter of the filter, and the hole diameter D1 of the hole defines a third performance parameter of the filter. 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 arranging the coupling bands in the holes, thereby fully meeting the actual use requirements.

Description

a filter

technical field

The present invention relates to the field of communication technologies, and in particular, to a filter applied in the field of communication.

Background technique

The dielectric waveguide filter is a microwave filter that uses a dielectric resonant cavity to achieve frequency selection 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 a standing wave oscillation. The main advantages of dielectric waveguide filters are large power capacity and low insertion loss. However, the existing dielectric filters are quite difficult to achieve capacitive coupling and have stray effects on the left and right remote ends, which limits the application of dielectric filters. Therefore, in response to the above requirements, it is necessary to propose further solutions.

SUMMARY OF THE INVENTION

The present invention aims to provide a filter to overcome the deficiencies in the prior art.

For solving the above-mentioned technical problems, the technical scheme of the present invention is:

A filter, comprising: a ceramic body, a metal layer disposed on the inner and outer surfaces of the ceramic body;

One side of the ceramic body is provided with a plurality of resonant cavities, and a hole through the ceramic body for capacitive coupling is provided between two of the plurality of resonant cavities, and the hole wall of the hole has an annular coupling band, The metal layer is not provided at the coupling strip, the width h1 of the coupling strip defines the first performance parameter of the filter, and the distance h2 between the coupling strip and one side of the ceramic body defines the width of the filter. The second performance parameter, the aperture D1 of the hole defines the third performance parameter of the filter.

As an improvement of the filter of the present invention, the hole is located at the midpoint of the 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 a circle, an ellipse, a polygon, or a special shape.

As an improvement of the filter of the present invention, the coupling band is defined by an annular area of the hole wall surface.

As an improvement of the filter of the present invention, the coupling strip is defined by an annular groove recessed inward from the hole wall.

As an improvement of the filter of the present invention, the diameter D2 of the annular groove defines a fourth performance parameter of the filter.

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

As an improvement of the filter of the present invention, 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 and the resonant cavities in the other column are separated by the second isolation cavity. isolated by the isolation chamber.

As an improvement of the filter of the present invention, the hole is located between the two resonant cavities 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 beneficial effects of the present invention are: the filter of the present invention realizes the capacitive coupling performance of the filter by opening holes between the resonant cavities; Capacitive coupling size, out-of-band suppression, remote suppression and other properties of the device can be adjusted to fully meet the actual use requirements.

Description of drawings

In order to explain the embodiments of the present invention or the technical solutions in the prior art more clearly, the following briefly introduces the accompanying drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments described in the present invention. For those of ordinary skill in the art, other drawings can also be obtained based on these drawings without any creative effort.

Fig. 1 is the top view of the filter removal metal layer of the present invention;

Fig. 2 is the bottom view of the filter of the present invention;

3 is an enlarged cross-sectional view in the direction of FIG. 1A-A in one embodiment;

4 is an enlarged cross-sectional view in the direction of FIG. 1A-A in another embodiment;

Fig. 5 is the S parameter curve diagram of the filter of the present invention;

It should be noted that the A-A direction is a direction perpendicular to the paper surface, and is drawn obliquely for the convenience of drawing.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

As shown in FIGS. 1 and 2 , the present invention provides a filter, which includes: a ceramic body 1 , and a metal layer 2 disposed on the inner and outer surfaces of the ceramic body 1 .

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

In one embodiment, the number of the resonant cavities 11 is six. In this case, the six resonant cavities 11 are arranged on one side of the ceramic body 1 in an array form. In this embodiment, the resonator cavities 11 in two adjacent columns of the three columns of resonance cavities 11 are isolated by the first isolation cavity 12 . The first isolation cavity 12 is a cross-shaped structure, and the four resonant cavities 11 are respectively distributed in the four regions divided by the first isolation cavity 12 . The resonant cavities 11 in the two adjacent columns are isolated from the resonant cavities 11 in the other column by the second isolation cavity 13 . The second isolation cavity 13 is substantially T-shaped.

As shown in FIGS. 3 and 4 , a hole 14 penetrating the ceramic body 1 for capacitive coupling is provided between two of the plurality of resonator cavities 11 , and the hole 14 realizes capacitive coupling while comparing with For opening blind holes, it also has the advantages of more convenient mold opening and higher yield. Because, when opening blind holes, the distance between the bottom of the blind hole and the surface of the ceramic body 1 requires precision, which significantly increases the process difficulty and cost of the device, and opening through holes overcomes this problem. Preferably, the hole 14 is located at the midpoint of the line connecting the two resonant cavities 11 . When there are six resonant cavities 11 and they are arranged in an array, the holes 14 are located between the two resonant cavities 11 in the remaining column. In addition, the cross-sectional shape of the hole 14 may be one of a circle, an ellipse, a polygon, or a special shape. Preferably, the cross-sectional shape of the hole 14 is circular.

In order to adjust the performance of capacitive coupling, out-of-band suppression, remote suppression, etc., the hole wall of the hole 14 has an annular coupling strip 141 , and the metal layer 2 is not provided at the coupling strip 141 . At this time, the width h1 of the coupling strip 141 defines the first performance parameter of the filter, and the distance h2 between the coupling strip 141 and one side of the ceramic body 1 defines the second performance parameter of the filter, so The aperture D1 of the hole 14 defines the third performance parameter of the filter.

Therefore, by changing one or more of the size parameters of the width h1 of the coupling strip 141 , the distance h2 from one side of the ceramic body 1 and the aperture D1 of the hole 14 , it is possible to realize the size of capacitive coupling, out-of-band suppression, remote Performances such as suppression are adaptively adjusted, so that the filter of the present invention can meet the usage requirements under corresponding conditions.

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

It can be seen from Fig. 5 that there are peaks at point A and point B distributed left and right in the L curve, which indicates that the filter of the present invention has capacitive coupling performance, and the height difference between the peaks at point A and point B reflects the out-of-band suppression. Impact. In addition, a C-point peak appears in the L curve, which indicates that the filter of the present invention can produce better-characterized far-end rejection.

As shown again in Figure 3, in one embodiment, the coupling strip 141 is defined by an annular area of the hole wall surface. In addition, the coupling strip 141 is processed by a milling cutter disposed at the end portion facing the hole wall. During processing, the milling cutter is controlled to mill out the metal layer 2 corresponding to the surface of the coupling strip 141 , so that the ceramic body 1 in the region where the coupling strip 141 is located is exposed.

As shown in FIG. 4 again, in another alternative embodiment, the coupling strip 141 is defined by an annular groove recessed inward from the hole wall. The coupling strip 141 is also machined by a milling cutter disposed at the end portion facing the hole wall. During processing, after the milling cutter is controlled to remove the metal layer 2 corresponding to the surface of the coupling strip 141 , the inward milling is continued, so that an annular groove structure is formed on the hole wall of the hole 14 .

In the above alternative embodiment, by forming an annular groove structure, the diameter D2 of the annular groove defines the fourth performance parameter of the filter. Therefore, the fourth performance parameter can adjust and optimize the performance of the filter together with the first, second, and third performance parameters.

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 to realize the electrical performance of the filter of the present invention, and preferably, the metal layer 2 may be a silver-plated layer or a copper-plated layer. In addition, the metal layer 2 can also be replaced by other layer structures with conductive properties.

To sum up, the filter of the present invention realizes the capacitive coupling performance of the filter by opening holes between the resonant cavities, and at the same time, by setting the coupling band in the holes, the capacitance coupling size and out-of-band suppression of the filter are effectively suppressed. , remote suppression and other properties can be adjusted to fully meet the actual use requirements.

It will be apparent to those skilled in the art that the present invention is not limited to the details of the above-described exemplary embodiments, but that the present invention may be embodied in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments are to be regarded in all respects as illustrative and not restrictive, and the scope of the invention is to be defined by the appended claims rather than the foregoing description, which are therefore intended to fall within the scope of the claims. All changes within the meaning and scope of the equivalents of , are included in the present invention. Any reference signs in the claims shall not be construed as limiting the involved claim.

In addition, it should be understood that although this specification is described in terms of embodiments, not each embodiment only includes an independent technical solution, and this description in the specification is only for the sake of clarity, and those skilled in the art should take the specification as a whole , the technical solutions in each embodiment can also be appropriately combined to form other implementations that can be understood by those skilled in the art.

Claims (9)

1. A filter, characterized in that the filter comprises: a ceramic body, a metal layer arranged on the inner and outer surfaces of the ceramic body; One side of the ceramic body is provided with a plurality of resonant cavities, and a hole through the ceramic body for capacitive coupling is provided between two of the plurality of resonant cavities, and the hole wall of the hole has an annular coupling band, The metal layer is not provided at the coupling strip, the width h1 of the coupling strip defines the first performance parameter of the filter, and the distance h2 between the coupling strip and the side of the ceramic body with the plurality of resonant cavities is h2 A second performance parameter of the filter is defined, a diameter D1 of the hole defines a third performance parameter of the filter, wherein the coupling band is defined by an annular groove recessed inwardly from the hole wall. 2 . The filter according to claim 1 , wherein the hole is located at the midpoint of the line connecting the two resonant cavities. 3 . 3 . The filter according to claim 1 , wherein the cross-sectional shape of the hole is one of a circle, an ellipse, a polygon, or a special shape. 4 . 4. The filter of claim 1, wherein the coupling band is defined by an annular region of the hole wall surface. 5. The filter of claim 1, wherein the diameter D2 of the annular groove defines a fourth performance parameter of the filter. 6 . The filter according to claim 1 , wherein the number of the resonant cavities is six, and the six resonant cavities are arranged on one side of the ceramic body in an array form. 7 . 7 . The filter according to claim 6 , wherein the resonant cavities in two adjacent columns of the three columns of resonant cavities are isolated by a first isolation cavity, and the resonant cavities in the two adjacent columns are separated from each other. 8 . The remaining row of resonant cavities is isolated by the second isolation cavity. 8 . The filter according to claim 7 , wherein the holes are located between the two resonant cavities in the remaining column. 9 . 9 . The filter according to claim 1 , wherein the metal layer is a silver-plated layer or a copper-plated layer. 10 .

Images