CN211125986U - Filter and communication equipment - Google Patents

Abstract

The application discloses a filter and communication equipment. The filter includes: a housing having a first direction and a second direction perpendicular to each other; the first filtering branch is arranged on the shell and consists of six filtering cavities which are sequentially coupled along a first coupling path; the second filtering branch is arranged on the shell and consists of five filtering cavities which are sequentially coupled along a second coupling path to form an inductive coupling zero point of the second filtering branch; the third filtering branch is arranged on the shell and consists of eight filtering cavities which are sequentially coupled along a third coupling path to form two capacitive coupling zeros of the third filtering branch; and the first common cavity is arranged on the shell and is respectively coupled with the first filtering cavity of the first filtering branch, the first filtering cavity of the second filtering branch and the first filtering cavity of the third filtering branch. By the mode, the size of the filter can be reduced, the number of taps and welding points is reduced, and the cost is reduced; and the signal isolation between the filtering branches of the filter can be improved.

Description

Filter and communication equipment

Technical Field

The present application relates to the field of communications technologies, and in particular, to a filter and a communications device.

Background

In a base station system for mobile communication, communication signals carrying communication data in a specific frequency range are generally transmitted through a transmitting antenna, and the communication signals are received through a receiving antenna. The signal received by the receiving antenna contains not only the communication signal carrying the communication data within the specific frequency range, but also a number of clutter or interference signals outside the specific frequency range. To obtain the communication signal carrying communication data in a specific frequency range transmitted by the transmitting antenna from the signal received by the receiving antenna, the signal received by the receiving antenna is usually filtered by a filter to filter out clutter or interference signals outside the specific frequency of the communication signal carrying communication data.

The inventor of the application finds that the volume of the existing filter and the number of taps are increased along with the increase of the filtering branches in long-term research and development work, so that the number of taps and the number of welding points are large, the cost is high, and the signal isolation between a plurality of filtering branches of the filter is poor.

SUMMERY OF THE UTILITY MODEL

The application provides a wave filter and communication equipment to reduce the volume of wave filter, reduce the quantity of taking a percentage and welding point, reduce cost, and improve the signal isolation between the filtering branch road of wave filter.

In order to solve the technical problem, the application adopts a technical scheme that: a filter is provided. The filter includes: a housing having a first direction and a second direction perpendicular to each other; the first filtering branch is arranged on the shell and consists of six filtering cavities which are sequentially coupled along a first coupling path; the second filtering branch is arranged on the shell and consists of five filtering cavities which are sequentially coupled along a second coupling path to form an inductive coupling zero point of the second filtering branch; the third filtering branch is arranged on the shell and consists of eight filtering cavities which are sequentially coupled along a third coupling path to form two capacitive coupling zeros of the third filtering branch; and the first common cavity is arranged on the shell and is respectively coupled with the first filtering cavity of the first filtering branch, the first filtering cavity of the second filtering branch and the first filtering cavity of the third filtering branch.

In order to solve the technical problem, the application adopts a technical scheme that: a communication device is provided. The communication equipment comprises an antenna and a radio frequency unit connected with the antenna, wherein the radio frequency unit comprises the filter and is used for filtering radio frequency signals.

The beneficial effects of the embodiment of the application are that: different from the prior art, the filter of the embodiment of the application comprises: a housing having a first direction and a second direction perpendicular to each other; the first filtering branch is arranged on the shell and consists of six filtering cavities which are sequentially coupled along a first coupling path; the second filtering branch is arranged on the shell and consists of five filtering cavities which are sequentially coupled along a second coupling path to form an inductive coupling zero point of the second filtering branch; the third filtering branch is arranged on the shell and consists of eight filtering cavities which are sequentially coupled along a third coupling path to form two capacitive coupling zeros of the third filtering branch; and the first common cavity is arranged on the shell and is respectively coupled with the first filtering cavity of the first filtering branch, the first filtering cavity of the second filtering branch and the first filtering cavity of the third filtering branch. The first filtering branch, the second filtering branch and the third filtering branch of the filter share the first common cavity, so that the size of the filter can be reduced, the first filtering branch, the second filtering branch and the third filtering branch can be connected with the common port through the first common cavity, and the ports do not need to be arranged for the first filtering branch, the second filtering branch and the third filtering branch respectively, therefore, the number of taps and tap welding points can be reduced, and the cost of the filter can be reduced; meanwhile, the first filtering branch circuit has no coupling zero point, and the type of the coupling zero point of the second filtering branch circuit is different from that of the coupling zero point of the third filtering branch circuit, so that the signal isolation among the first filtering branch circuit, the second filtering branch circuit and the third filtering branch circuit can be improved.

Drawings

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

FIG. 1 is a schematic diagram of an embodiment of a filter according to the present application;

FIG. 2 is a schematic diagram of an embodiment of a filter according to the present application;

FIG. 3 is a schematic diagram of a topology of a first filtering branch in an embodiment of a filter according to the present application;

FIG. 4 is a schematic diagram of a topology of a second filtering branch in an embodiment of the filter of the present application;

FIG. 5 is a schematic diagram of a topology of a third filtering branch in an embodiment of the filter of the present application;

FIG. 6 is a schematic diagram of a topology of an eighth filtering branch in an embodiment of the filter of the present application;

FIG. 7 is a diagram illustrating simulation results of an embodiment of the filter of the present application;

fig. 8 is a schematic structural diagram of an embodiment of the communication device of the present application.

Detailed Description

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, 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 application.

The terms "first" and "second" in this application are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. In the description of the present application, "plurality" means at least two, e.g., two, three, etc., unless explicitly specifically limited otherwise. Furthermore, the terms "include" and "have," as well as any variations thereof, are intended to cover non-exclusive inclusions. For example, a process, method, system, article, or apparatus that comprises a list of steps or elements is not limited to only those steps or elements listed, but may alternatively include other steps or elements not listed, or inherent to such process, method, article, or apparatus.

First, a filter is proposed, as shown in fig. 1, 3, 4 and 5, fig. 1 is a schematic structural diagram of an embodiment of the filter of the present application; FIG. 3 is a schematic diagram of a topology of a first filtering branch in an embodiment of a filter according to the present application; FIG. 4 is a schematic diagram of a topology of a second filtering branch in an embodiment of the filter of the present application; fig. 5 is a schematic diagram of a topology of a third filtering branch in an embodiment of the filter of the present application. The filter 10 of the present embodiment includes: the filter comprises a shell 11, a first filtering branch 12, a second filtering branch 13, a third filtering branch 14 and a first common cavity ABC, wherein the shell 11 has a first direction x and a second direction y which are perpendicular to each other; the first filtering branch 12 is arranged on the shell 11 and consists of six filtering cavities A1-A6 which are sequentially coupled along a first coupling path; the second filtering branch 13 is arranged on the housing 11 and is composed of five filtering cavities B1-B5 coupled in sequence along a second coupling path, and the five filtering cavities B1-B5 of the second filtering branch 13 form an inductive coupling zero point of the second filtering branch 13; the third filtering branch 14 is arranged on the housing 11 and consists of eight filtering cavities C1-C8 coupled in sequence along a third coupling path to form two capacitive coupling zeros of the third filtering branch 14; the first common cavity ABC is disposed on the housing 11, and the first common cavity ABC is coupled to the first filtering cavity a1 of the first filtering branch 12, the first filtering cavity B1 of the second filtering branch 13, and the first filtering cavity C1 of the third filtering branch 14, respectively.

As shown in fig. 1, the six filter cavities a1-a6 of the first filter branch 12 include: a first filter cavity A1, a second filter cavity A2, a third filter cavity A3, a fourth filter cavity A4, a fifth filter cavity A5 and a sixth filter cavity A6; the five filter chambers B1-B5 of the second filter branch 13 comprise: a first filter cavity B1, a second filter cavity B2, a third filter cavity B3, a fourth filter cavity B4 and a fifth filter cavity B5; the eight filter cavities C1-C8 of the third filter branch 14 comprise: a first filter cavity C1, a second filter cavity C2, a third filter cavity C3, a fourth filter cavity C4, a fifth filter cavity C5, a sixth filter cavity C6, a seventh filter cavity C7 and an eighth filter cavity C8.

Different from the prior art, the first filtering branch 12, the second filtering branch 13, and the third filtering branch 14 of the filter 10 of this embodiment share the first common cavity ABC, so that the size of the filter 10 can be reduced, and the first filtering branch 12, the second filtering branch 13, and the third filtering branch 14 can be connected to a common port through the first common cavity ABC without respectively providing ports for the first filtering branch 12, the second filtering branch 13, and the third filtering branch 14, so that the number of taps and tap welding points can be reduced, and the cost of the filter 10 can be reduced; meanwhile, the first filtering branch 12 has no coupling zero, and the type of the coupling zero of the second filtering branch 13 is different from the type of the coupling zero of the third filtering branch 14, so that the signal isolation among the first filtering branch 12, the second filtering branch 13 and the third filtering branch 14 can be improved.

In addition, the filtering branches of the embodiment of the application are provided with coupling zero points, so that the characteristics of out-of-band rejection and the like of signals of the filtering branches can be improved.

The first filtering branch 12 has no cross coupling, adopts pure window coupling, has good consistency of window coupling, is low in cost, and does not need to be provided with other materials (such as inductive cross coupling materials); the coupling zero points of the second filtering branch 13 are all inductive coupling zero points, so that the material consistency can be improved, and the temperature drift can be reduced; the coupling zero points of the third filtering branch 14 are all capacitive coupling, so that the consistency of materials can be improved, the process is simplified, and the cost is saved.

Alternatively, as shown in fig. 1, the first filter cavity a1 to the sixth filter cavity a6 of the first filter branch 12 and the second filter cavity B2 to the fifth filter cavity B5 of the second filter branch 13 are divided into three columns arranged in sequence along the first direction x; the first filtering cavity a1, the second filtering cavity a2, the third filtering cavity A3 and the fourth filtering cavity a4 of the first filtering branch 12 are in a row and are sequentially and adjacently arranged along the second direction y, the third filtering cavity B3 and the fifth filtering cavity B5 of the second filtering branch 13, and the fifth filtering cavity a5 and the sixth filtering cavity a6 of the first filtering branch 12 are in a row and are sequentially and adjacently arranged along the second direction y; and the first filtering cavity a1 of the first filtering branch 12 is also respectively adjacent to the first common cavity ABC, the third filtering cavity B3 of the second filtering branch 13 and the fifth filtering cavity B5 of the second filtering branch 13.

From the above analysis, it can be known that the first filtering cavity a1 to the sixth filtering cavity a6 of the first filtering branch 12 and the second filtering cavity B2 to the fifth filtering cavity B5 of the second filtering branch 13 are arranged in three rows, and the three rows of filtering cavities are adjacently arranged, a plurality of filtering cavities in each row are adjacently arranged in sequence, and the three rows of filtering cavities are alternately arranged, so that the arrangement space of the first filtering branch 12 and the second filtering branch 13 can be reduced.

As shown in fig. 1, the first common cavity ABC, the first filtering cavity B1 of the second filtering branch 13, and the first filtering cavity C1 to the eighth filtering cavity C8 of the third filtering branch 14 are divided into two rows sequentially arranged along the first direction x; the first common cavity ABC, the first filter cavity C1, the second filter cavity C2, the third filter cavity C3 and the fourth filter cavity C4 of the third filter branch 14 are in a row and are sequentially and adjacently arranged along the second direction y; the first filtering cavity B1 of the second filtering branch 13 and the seventh filtering cavity C7 to the fifth filtering cavity C5 of the third filtering branch 14 are in a row and are sequentially and adjacently arranged along the second direction y; and the first filter cavity C1 of the third filter branch 14 is respectively adjacent to the first filter cavity B1 of the second filter branch 13 and the eighth filter cavity C8 of the third filter branch 14.

From the above analysis, it can be known that the first common cavity ABC, the first filtering cavity B1 of the second filtering branch 13 and the first filtering cavity C1 to the eighth filtering cavity C8 of the third filtering branch 14 are arranged in two rows, and the two rows of filtering cavities are adjacent to each other, a plurality of filtering cavities in each row are adjacent to each other in sequence, and the two rows of filtering cavities are staggered to reduce the arrangement space of the first common cavity ABC, the second filtering branch 13 and the third filtering branch 14.

The projection of the centre of the first filter cavity a1 of the first filter branch 12 in the first direction x is located between the centre of the first common cavity ABC and the projection of the centre of the third filter cavity B3 of the second filter branch 13 in the first direction x, and the projection of the centre of the first common cavity ABC in the second direction y is located between the centre of the first filter cavity a1 of the first filter branch 12 and the projection of the centre of the first filter cavity C1 of the third filter branch 14 in the second direction y.

As can be seen from the above analysis, the first filtering branch 12 and the second filtering branch 13 are distributed along the first direction x, and the filtering cavity in the first filtering branch 12, the filtering cavity in the second filtering branch 13, and the filtering cavity in the third filtering branch 14 are all distributed along the first direction x; the first filtering branch 12, the first common cavity ABC and the third filtering branch 14 are distributed along the second direction y, so that the filter 10 can be prevented from being too large in the first direction x and the second direction y.

Further, as shown in fig. 1, the six filter cavities a1-a6 of the first filter branch 12 have the same size, and as can be seen from the arrangement of the filter cavities, the distances between the centers of any two adjacent filter cavities are equal, so that the cavity array of the first filter branch 12 can be more compact, and the arrangement space of the first filter branch 12 can be reduced; the five filter cavities B1-B5 of the second filter branch 13 are the same in size, and the distances between the centers of any two adjacent filter cavities are equal, so that the cavity arrangement of the second filter branch 13 can be more compact, and the arrangement space of the second filter branch 13 can be reduced; the eight filter cavities C1-C8 of the third filter branch 14 have the same size, and the distances between the centers of any two adjacent filter cavities are equal, so that the cavity array of the third filter branch 14 is more compact, and the arrangement space of the third filter branch 14 can be reduced.

Alternatively, the topology of the first filtering branch 12 is as shown in fig. 3.

Alternatively, as shown in fig. 1, the second filter cavity B2 of the second filter branch 13 is inductively cross-coupled with the fourth filter cavity B4 of the second filter branch 13 to form an inductive coupling zero of the second filter branch 13.

The coupling zero is also referred to as a transmission zero. The transmission zero is the transmission function of the filter is equal to zero, namely, the electromagnetic energy cannot pass through the network on the frequency point corresponding to the transmission zero, so that the full isolation effect is achieved, the suppression effect on signals outside the passband is achieved, and the high isolation among the multiple passbands can be better achieved.

Generally, the inductive coupling zero point is realized by a window, and a metal coupling rib is arranged on the window. As shown in fig. 4, a window and a metal coupling rib (not shown, shown by a dotted line) may be provided between the second filter chamber B2 and the fourth filter chamber B4; in this embodiment, the inductive cross coupling is realized by the metal coupling rib, and the metal coupling rib is less subject to the change of the external temperature, so that the temperature drift of the second filtering branch 13 can be reduced.

Optionally, as shown in fig. 1, capacitive cross-coupling is formed between the third filter cavity C3 of the third filter branch 14 and the sixth filter cavity C6 of the third filter branch 14, and between the fourth filter cavity C4 of the third filter branch 14 and the sixth filter cavity C6 of the third filter branch 14, respectively, so as to form two capacitive coupling zeros of the third filter branch 14.

Generally, the capacitive coupling zero is realized by a capacitive cross-coupling element, and a typical capacitive cross-coupling element may be a flying bar. As shown in fig. 5, flying rods (not shown, shown by dotted lines) may be respectively disposed between the third filter chamber C3 and the sixth filter chamber C6 and between the fourth filter chamber C4 and the sixth filter chamber C6.

From the above analysis, it can be known that the distance between the third filter cavity C3 and the sixth filter cavity C6 and the distance between the fourth filter cavity C4 and the sixth filter cavity C6 are equal, and two capacitive coupling zeros of the third filter branch 14 can be implemented by using two flying bars with the same model, so that the consistency of materials can be improved, the process is simplified, and the cost is saved.

In another embodiment, as shown in fig. 2 to 7, fig. 2 is a schematic structural diagram of an embodiment of the filter of the present application; FIG. 3 is a schematic diagram of a topology of a first filtering branch in an embodiment of a filter according to the present application; FIG. 4 is a schematic diagram of a topology of a second filtering branch in an embodiment of the filter of the present application; FIG. 5 is a schematic diagram of a topology of a third filtering branch in an embodiment of the filter of the present application; FIG. 6 is a schematic diagram of a topology of an eighth filtering branch in an embodiment of the filter of the present application; FIG. 7 is a diagram illustrating simulation results of an embodiment of the filter of the present application.

As shown in fig. 2, the filter 10 of the present embodiment further includes, on the basis of the foregoing embodiment: a fourth filtering branch 15, a fifth filtering branch 16 and a second common cavity DE; the fourth filtering branch 15 is arranged on the housing 11, and the fourth filtering branch 15 is composed of six filtering cavities D1-D6 which are coupled in sequence along a fourth coupling path; the fifth filtering branch 16 is arranged on the housing 11, and the fifth filtering branch 16 is composed of five filtering cavities E1-E5 coupled in sequence along a fifth coupling path to form an inductive coupling zero point of the fifth filtering branch 16; the second common cavity DE is provided in the housing 11 and is coupled to the first filter cavity D1 of the fourth filter branch 15 and the first filter cavity E1 of the fifth filter branch 16, respectively.

As shown in fig. 2, the six filter cavities D1-D6 of the fourth filter branch 15 include: a first filter cavity D1, a second filter cavity D2, a third filter cavity D3, a fourth filter cavity D4, a fifth filter cavity D5 and a sixth filter cavity D6; the five filter chambers E1-E5 of the fifth filter branch 16 comprise: a first filter cavity E1, a second filter cavity E2, a third filter cavity E3, a fourth filter cavity E4 and a fifth filter cavity E5.

As shown in fig. 2, the second common cavity DE, the first filtering cavity D1 to the sixth filtering cavity D6 of the fourth filtering branch 15, and the first filtering cavity E1 to the fifth filtering cavity E5 of the fifth filtering branch 16 are divided into four rows arranged in sequence along the first direction x; the fifth filter cavity D5 and the sixth filter cavity D6 of the fourth filter branch 15 are in a row and are sequentially and adjacently arranged along the second direction y, the third filter cavity D3 and the fourth filter cavity D4 of the fourth filter branch 15 are in a row and are sequentially and adjacently arranged along the second direction y, the second filter cavity D2 of the fourth filter branch 15 and the third filter cavity E3 of the fifth filter branch 16 are in a row and are sequentially and adjacently arranged along the second direction y, the first filter cavity E1, the second filter cavity E2, the fourth filter cavity E4 and the fifth filter cavity E5 of the second common cavity DE and the fifth filter branch 16 are in a row and are sequentially and adjacently arranged along the second direction y; the third filtering cavity D3 of the fourth filtering branch 15 is further disposed adjacent to the fifth filtering cavity D5 of the fourth filtering branch 15, the second filtering cavity D2 of the fourth filtering branch 15 and the third filtering cavity E3 of the fifth filtering branch 16, respectively, and the second filtering cavity E2 of the fifth filtering branch 16 is further disposed adjacent to the second filtering cavity D2 of the fourth filtering branch 15 and the third filtering cavity E3 of the fifth filtering branch 16, respectively.

From the above analysis, it can be known that the filter cavities of the second common cavity DE, the fourth filter branch 15 and the fifth filter branch 16 are arranged in four rows, the four rows of filter cavities are adjacently arranged, the plurality of filter cavities in each row are sequentially adjacently arranged, the two rows of filter cavities are arranged in a staggered manner, and the arrangement space of the second common cavity DE, the fourth filter branch 15 and the fifth filter branch 16 can be reduced.

Further, as shown in fig. 2, the six filter cavities D1-D6 of the fourth filter branch 15 have the same size, and as can be seen from the arrangement of the filter cavities, the distances between the centers of any two adjacent filter cavities are equal, so that the cavity array of the fourth filter branch 15 can be more compact, and the arrangement space of the fourth filter branch 15 can be reduced; the five filter cavities E1-E5 of the fifth filter branch 16 have the same size, and the distances between the centers of any two adjacent filter cavities are equal, so that the row cavities of the fifth filter branch 16 are more compact, and the arrangement space of the fifth filter branch 16 can be reduced.

The distribution and the topological structure of the coupling zero point of the fourth filtering branch 15 are the same as the topological structure of the first filtering branch 12, which is not described herein; the distribution and topology of the coupling zero of the fifth filtering branch 16 are the same as those of the second filtering branch 13, and are not described herein.

Optionally, as shown in fig. 2, the filter 10 further includes: and the sixth filtering branch 17 is arranged on the shell 11, and the sixth filtering branch 17 is composed of eight filtering cavities F1-F8 which are sequentially coupled along a sixth coupling path to form two capacitive coupling zeros of the sixth filtering branch 17. The coupling zero points of the sixth filtering branch 17 are all capacitive coupling zero points, so that the consistency of materials can be improved.

Wherein the eight filter cavities F1-F8 of the sixth filter branch 17 include: a first filter cavity F1, a second filter cavity F2, a third filter cavity F3, a fourth filter cavity F4, a fifth filter cavity F5, a sixth filter cavity F6, a seventh filter cavity F7 and an eighth filter cavity F8.

The third filtering cavity F3 to the eighth filtering cavity F8 of the sixth filtering branch 17 are divided into four rows arranged in sequence along the first direction x; the fifth filtering cavity F5, the sixth filtering cavity F6 and the seventh filtering cavity F7 of the sixth filtering branch 17 are in a row and are sequentially and adjacently arranged along the second direction y, and the fourth filtering cavity F4, the third filtering cavity F3 and the eighth filtering cavity F8 of the sixth filtering branch 17 are in a row and are sequentially and adjacently arranged along the second direction y; the third filtering cavity F3 of the sixth filtering branch 17 is also respectively adjacent to the sixth filtering cavity F6, the seventh filtering cavity F7, the second filtering cavity F2 of the sixth filtering branch 17 and the first filtering cavity D1 of the fourth filtering branch 15, and the second filtering cavity F2 of the sixth filtering branch 17 is also adjacent to the eighth filtering cavity F8 of the sixth filtering branch 17, the first filtering cavity F1, the second common cavity DE and the first filtering cavity D1 of the fourth filtering branch 15; the first filter cavity F1 of the sixth filter branch 17 overlaps the projection of the second common cavity DE in the first direction x, the second filter cavity F2 of the sixth filter branch 17 overlaps the projection of the first filter cavity D1 of the fourth filter branch 15 in the first direction x, and the fourth filter cavity F4 of the sixth filter branch 17 overlaps the projection of the third filter cavity D3 of the fourth filter branch 15 in the first direction x.

As can be seen from the above analysis, the filter cavities of the sixth filter branch 17 and the fourth filter branch 14 are in the same column and are disposed adjacent to each other, so that the cavities can be arranged more regularly, and the size of the filter 10 can be reduced.

The distribution and topology of the coupling zero of the sixth filtering branch 17 are the same as those of the third filtering branch 14, and are not described herein.

Optionally, as shown in fig. 2, the filter 10 further includes: the seventh filtering branch 18 is arranged on the shell 11, and the seventh filtering branch 18 is composed of eight filtering cavities G1-G8 which are sequentially coupled along a seventh coupling path to form two capacitive coupling zeros of the seventh filtering branch 18; coupling zero points of the seventh filtering branch 18 are all capacitive coupling zero points, so that consistency of materials can be improved.

Wherein the eight filter cavities G1-G8 of the seventh filter branch 18 include: the filter comprises a first filter cavity G1, a second filter cavity G2, a third filter cavity G3, a fourth filter cavity G4, a fifth filter cavity G5, a sixth filter cavity G6, a seventh filter cavity G7 and an eighth filter cavity G8.

The first filtering cavity G1 to the eighth filtering cavity G8 of the seventh filtering branch 18 are divided into four rows arranged in sequence along the first direction x; the first filtering cavity G1 and the eighth filtering cavity G8 of the seventh filtering branch 18 are in a row and are sequentially and adjacently arranged along the second direction y, the second filtering cavity G2 and the seventh filtering cavity G7 of the seventh filtering branch 18 are in a row and are sequentially and adjacently arranged along the second direction y, the third filtering cavity G3 and the sixth filtering cavity G6 of the seventh filtering branch 18 are in a row and are sequentially and adjacently arranged along the second direction y, and the fourth filtering cavity G4 and the fifth filtering cavity G5 of the seventh filtering branch 18 are in a row and are sequentially and adjacently arranged along the second direction y; the seventh filtering cavity G7 of the seventh filtering branch 18 is further disposed adjacent to the first filtering cavity G1, the eighth filtering cavity G8, the third filtering cavity G3 and the sixth filtering cavity G6 of the seventh filtering branch 18, respectively, and the fourth filtering cavity G4 of the seventh filtering branch 18 is further disposed adjacent to the seventh filtering cavity C7 and the sixth filtering cavity C6 of the third filtering branch 14.

The eight filter cavities G1-G8 of the seventh filter branch 18 are arranged in multiple rows, so that the rows of cavities are more regular, and the arrangement space is reduced, and the seventh filter branch 18 and the third filter branch 14 are arranged adjacently, so that the size of the filter 10 can be reduced.

The coupling zero distribution and the topology of the seventh filtering branch 18 are the same as those of the third filtering branch 14, and are not described herein again.

Optionally, as shown in fig. 2, the filter 10 further includes: the eighth filtering branch 19 is arranged on the shell 11, and the eighth filtering branch 19 consists of eight filtering cavities H1-H8 which are sequentially coupled along an eighth coupling path to form two capacitive coupling zeros of the eighth filtering branch 19; coupling zero points of the eighth filtering branch circuit 19 are all capacitive coupling zero points, so that the consistency of materials can be improved.

Wherein, the eight filter cavities H1-H8 of the eighth filter branch 19 include: the filter comprises a first filter cavity H1, a second filter cavity H2, a third filter cavity H3, a fourth filter cavity H4, a fifth filter cavity H5, a sixth filter cavity H6, a seventh filter cavity H7 and an eighth filter cavity H8.

The second filtering cavity H2 to the sixth filtering cavity H6 of the eighth filtering branch 19 are divided into two rows arranged in sequence along the first direction x; the second filtering cavity H2, the third filtering cavity H3 and the fourth filtering cavity H4 of the eighth filtering branch 19 are in a row and are sequentially and adjacently arranged along the second direction y, and the sixth filtering cavity H6 and the fifth filtering cavity H5 of the eighth filtering branch 19 are in a row and are sequentially and adjacently arranged along the second direction y; the third filter cavity H3 of the eighth filter branch 19 is further disposed adjacent to the fifth filter cavity H5 and the sixth filter cavity H6 of the eighth filter branch 19, and the fifth filter cavity E5 of the fifth filter branch 16, respectively, and the fifth filter cavity H5 of the eighth filter branch 19 is further disposed adjacent to the fourth filter cavity H4 of the eighth filter branch 19, and the fourth filter cavity D4 and the sixth filter cavity D6 of the fourth filter branch 15; the fourth filter cavity H4 of the eighth filter branch 19 overlaps the projection of the third filter cavity E3 of the fifth filter branch 16 in the first direction x, and the fifth filter cavity H5 of the eighth filter branch 19 overlaps the projection of the fourth filter cavity D4 of the fourth filter branch 15 in the first direction x; the first filter cavity H1, the second filter cavity H2, the sixth filter cavity H6, the seventh filter cavity H7 and the eighth filter cavity H8 of the eighth filter branch 19 are sequentially and adjacently arranged, and the distance between the projection of the center of the second filter cavity H2, the center of the sixth filter cavity H6, the center of the seventh filter cavity H7 and the center of the eighth filter cavity H8 of the eighth filter branch 19 in the first direction x and the projection of the center of the first filter cavity H1 of the eighth filter branch 19 in the first direction x gradually increases; the projections of the seventh filter cavity H7 and the eighth filter cavity H8 of the eighth filter branch 19 in the second direction y overlap, and the projection of the center of the second filter cavity H2 of the eighth filter branch 19 in the second direction y is located between the center of the first filter cavity H1 of the eighth filter branch 19 and the projection of the center of the third filter cavity H3 of the eighth filter branch 19 in the second direction y.

As can be seen from the above analysis, the filter cavity of the eighth filter branch 19, the filter cavity of the fourth filter branch 14, and the filter cavity of the fifth filter branch 16 are arranged in the same row and adjacent to each other, so that the cavity arrangement is more regular, and the size of the filter 10 can be reduced.

Further, as shown in fig. 2, the eight filter cavities H1-H8 of the eighth filter branch 19 have the same size, and as can be seen from the arrangement of the filter cavities, the distances between the centers of any two adjacent filter cavities are equal, so that the cavity array of the eighth filter branch 19 can be more compact, and the arrangement space of the eighth filter branch 19 can be reduced.

As shown in fig. 2, capacitive cross coupling is respectively formed between the third filter cavity H3 of the eighth filter branch 19 and the fifth filter cavity H5 of the eighth filter branch 19, and between the third filter cavity H3 of the eighth filter branch 19 and the sixth filter cavity H6 of the eighth filter branch 19, so as to form two capacitive coupling zeros of the eighth filter branch 19.

As shown in fig. 6, flying rods (not shown, shown in dotted lines) may be disposed between the third filter chamber H3 and the fifth filter chamber H5 and between the third filter chamber H3 and the sixth filter chamber H6, respectively.

From the above analysis, it can be known that the distance between the third filter cavity H3 and the fifth filter cavity H5 and the distance between the third filter cavity H3 and the sixth filter cavity H6 are equal, and two capacitive coupling zeros of the eighth filter branch 19 can be realized by using two flying bars with the same type, so that the consistency of materials can be improved, the process is simplified, and the cost is saved.

Optionally, the seventh filtering branch 18 and the third filtering branch 14 are arranged adjacently along the first direction x; the first filtering branch 12, the second filtering branch 13, the third filtering branch 14 and the seventh filtering branch 18 are arranged in a first region (not shown) of the housing 11, the fourth filtering branch 15, the fifth filtering branch 16, the sixth filtering branch 17 and the eighth filtering branch 18 are arranged in a second region (not shown) of the housing 11, and the first region and the second region are arranged at intervals; an input/output port may be provided at a spaced region between the first region and the second region to reduce the length of the tap.

Further, as shown in fig. 2, the housing 11 is further provided with: a first input port (not shown) connected to the first common cavity ABC; a second input port (not shown) connected to the second common chamber DE; a third input port (not shown) connected to the first filter chamber F1 of the sixth filter branch 17; a fourth input port (not shown) connected to the first filter cavity G1 of the seventh filter branch 18; a fifth input port (not shown) connected to the first filter chamber H1 of the eighth filter branch 19; the first output port (not shown) to the eighth output port (not shown) are respectively connected to the sixth filtering cavity a6 of the first filtering branch 12, the fifth filtering cavity B5 of the second filtering branch 13, the eighth filtering cavity C8 of the third filtering branch 14, the sixth filtering cavity D6 of the fourth filtering branch 15, the fifth filtering cavity E5 of the fifth filtering branch 16, the eighth filtering cavity F8 of the sixth filtering branch 17, the eighth filtering cavity G8 of the seventh filtering branch 18, and the eighth filtering cavity H8 of the eighth filtering branch 19.

The port is used for filtering signal transmission; the ports may each be taps.

As shown in fig. 2, in the first filter branch 12, the coupling bandwidth between the first input port of the present embodiment and the first filter cavity a1 is in the range of 129MHz-133 MHz; the coupling bandwidth between the first filter cavity a1 and the second filter cavity a2 is in the range of 108MHz112 MHz; the coupling bandwidth between the second filter cavity a2 and the third filter cavity A3 is in the range of 77MHz-81 MHz; the coupling bandwidth between the third filter cavity A3 and the fourth filter cavity a4 is in the range of 74MHz-78 MHz; the coupling bandwidth between the fourth filter cavity a4 and the fifth filter cavity a5 is in the range of 77MHz-81 MHz; the coupling bandwidth between the fifth filter cavity a5 and the sixth filter cavity a6 is in the range of 108MHz112 MHz; the coupling bandwidth between the sixth filter cavity a6 and the first output port is in the range of 129MHz-133MHz, which can meet the design requirements.

The resonant frequencies of the first filter cavity a1 to the sixth filter cavity a6 of the first filter branch 12 are sequentially in the following ranges: 2348MHz-2350MHz, 2348MHz-2350MHz and 2348MHz-2350 MHz.

Therefore, the resonant frequency of each filter cavity is the same, and the convenience of manufacturing and debugging is improved; the method can be manufactured by adopting the same specification parameters, and the required parameter range can be reached only by simple debugging in the actual process.

As shown in fig. 2, in the second filter branch 13, the coupling bandwidth between the first input port of the present embodiment and the first filter cavity B1 is in the range of 180MHz-184 MHz; the coupling bandwidth between the first filter cavity B1 and the second filter cavity B2 ranges from 151MHz to 155 MHz; the coupling bandwidth between the second filter cavity B2 and the third filter cavity B3 ranges from 92MHz to 96 MHz; the coupling bandwidth between the second filter cavity B2 and the fourth filter cavity B4 ranges from 61MHz to 65 MHz; the coupling bandwidth between the third filter cavity B3 and the fourth filter cavity B4 ranges from 92MHz to 96 MHz; the coupling bandwidth between the fourth filter cavity B4 and the fifth filter cavity B5 ranges from 151MHz to 155 MHz; the coupling bandwidth between the fifth filter cavity B5 and the second output port is in the range of 180MHz-184MHz, which can meet the design requirements.

The resonant frequencies of the first filtering cavity B1 to the fifth filtering cavity B5 of the second filter branch 13 are sequentially in the following ranges: 1789MHz to 1791MHz, 1788MHz to 1790MHz, 1845MHz to 1847MHz, 1788MHz to 1790MHz, 1789MHz to 1791 MHz.

Therefore, the resonant frequencies of the filter cavities are basically the same, and the convenience of manufacturing and debugging is improved; the method can be manufactured by adopting the same specification parameters, and the required parameter range can be reached only by simple debugging in the actual process.

As shown in fig. 2, in the third filter branch 14, the coupling bandwidth between the first input port of the present embodiment and the first filter cavity C1 is in the range of 158MHz-162 MHz; the coupling bandwidth between the first filter cavity C1 and the second filter cavity C2 ranges from 132MHz to 136 MHz; the coupling bandwidth between the second filter chamber C2 and the third filter chamber C3 ranges from 94MHz to 98 MHz; the coupling bandwidth between the third filter chamber C3 and the fourth filter chamber C4 ranges from 84MHz to 88 MHz; the coupling bandwidth between the third filter cavity C3 and the sixth filter cavity C6 is in the range of (-27) MHz- (-23) MHz; the coupling bandwidth between the fourth filter cavity C4 and the fifth filter cavity C5 ranges from 104MHz to 108 MHz; the coupling bandwidth between the fourth filter cavity C4 and the sixth filter cavity C6 is in the range of (-28) MHz- (-27) MHz; the coupling bandwidth between the fifth filter cavity C5 and the sixth filter cavity C6 ranges from 80MHz to 84 MHz; the coupling bandwidth between the sixth filtering cavity C6 and the seventh filtering cavity C7 ranges from 94MHz to 98 MHz; the coupling bandwidth between the seventh filtering cavity C7 and the eighth filtering cavity C8 ranges from 132MHz to 136 MHz; the coupling bandwidth between the eighth filter cavity C8 and the third output port is in the range of 158MHz-162MHz, which can meet the design requirement.

The resonant frequencies of the first filtering cavity C1 to the eighth filtering cavity C8 of the third filter branch 14 are sequentially in the following ranges: 2593MHz-2595MHz, 2601MHz-2603MHz, 2567MHz-2569MHz, 2593MHz-2595MHz and 2593MHz-2595 MHz.

Therefore, the resonant frequencies of the filter cavities are basically the same, and the convenience of manufacturing and debugging is improved; the method can be manufactured by adopting the same specification parameters, and the required parameter range can be reached only by simple debugging in the actual process.

As shown in fig. 7, the bandwidth of the first filtering branch 12 is in the range of 2299MHz-2301MHz, the frequency band curve is shown as S1, and the rejection of the first filtering branch 12 satisfies: 9KHz-960MHz is greater than or equal to 40dB, 1710MHz-1880MHz is greater than or equal to 25dB, 1920MHz-2170MHz is greater than or equal to 25dB, 2496MHz-2690MHz is greater than or equal to 25dB, 3400MHz-3800MHz is greater than or equal to 25 dB.

The bandwidth of the second filtering branch 13 is in the range of 1709MHz-1881MHz, the frequency band curve is as shown in S2, and the suppression of the second filtering branch 13 satisfies: 9KHz-960MHz is greater than or equal to 40dB, 1920MHz-2170MHz is greater than or equal to 25dB, 2300MHz-2690MHz is greater than or equal to 25dB, 3400MHz-3800MHz is greater than or equal to 25 dB.

The bandwidth of the third filtering branch 14 is in the range of 2514MHz-2676MHz, the frequency band curve is as shown in S3, and the rejection of the third filtering branch 14 satisfies: 9KHz-960MHz is greater than or equal to 40dB, 1710MHz-1880MHz is greater than or equal to 25dB, 1920MHz-2170MHz is greater than or equal to 25dB, 2483.5MHz-2500MHz is greater than or equal to 28dB, 2700MHz-2900MHz is greater than or equal to 25dB, 3400MHz-3800MHz is greater than or equal to 25 dB.

It can be seen that the bandwidths of the first filtering branch 12, the second filtering branch 13 and the third filtering branch 14 are different, and the signal isolation is high.

The radio frequency parameters and simulation results of the fourth filtering branch 15 are the same as those of the first filtering branch 12, the radio frequency parameters and simulation results of the fifth filtering branch 16 are the same as those of the second filtering branch 13, and the radio frequency parameters and simulation results of the sixth filtering branch 17 and the seventh filtering branch 18 are the same as those of the third filtering branch 14, which are not described herein again.

It should be noted that the parameters (e.g., frequency point and suppression) of two or more coupling zeros of the present application may be the same; in the simulation diagram, the coupling zeros of the same parameters are shown as the same coupling zeros.

Some embodiments of the present application are referred to as filters, and may also be referred to as duplexers or combiners.

The present application further provides a communication device, as shown in fig. 8, fig. 8 is a schematic structural diagram of an embodiment of the communication device of the present application. The communication device of the present embodiment includes an antenna 32 and a radio frequency unit 31 connected to the antenna 32, the radio frequency unit 31 includes a filter 10 as shown in the above-mentioned embodiment, and the filter 10 is used for filtering a radio frequency signal.

In other embodiments, the rf Unit 31 may be integrated with the Antenna 32 to form an Active Antenna Unit (AAU).

Different from the prior art, the filter of the embodiment of the application comprises: a housing having a first direction and a second direction perpendicular to each other; the first filtering branch is arranged on the shell and consists of six filtering cavities which are sequentially coupled along a first coupling path; the second filtering branch is arranged on the shell and consists of five filtering cavities which are sequentially coupled along a second coupling path to form an inductive coupling zero point of the second filtering branch; the third filtering branch is arranged on the shell and consists of eight filtering cavities which are sequentially coupled along a third coupling path to form two capacitive coupling zeros of the third filtering branch; and the first common cavity is arranged on the shell and is respectively coupled with the first filtering cavity of the first filtering branch, the first filtering cavity of the second filtering branch and the first filtering cavity of the third filtering branch. The first filtering branch, the second filtering branch and the third filtering branch of the filter share the first common cavity, so that the size of the filter can be reduced, the first filtering branch, the second filtering branch and the third filtering branch can be connected with the common port through the first common cavity, and the ports do not need to be arranged for the first filtering branch, the second filtering branch and the third filtering branch respectively, therefore, the number of taps and tap welding points can be reduced, and the cost of the filter can be reduced; meanwhile, the first filtering branch circuit has no coupling zero point, and the type of the coupling zero point of the second filtering branch circuit is different from that of the coupling zero point of the third filtering branch circuit, so that the signal isolation among the first filtering branch circuit, the second filtering branch circuit and the third filtering branch circuit can be improved.

The above description is only for the purpose of illustrating embodiments of the present application and is not intended to limit the scope of the present application, and all modifications of equivalent structures and equivalent processes, which are made by the contents of the specification and the drawings of the present application or are directly or indirectly applied to other related technical fields, are also included in the scope of the present application.

Claims (10)

1. A filter, characterized in that the filter comprises:

a housing having a first direction and a second direction perpendicular to each other;

the first filtering branch is arranged on the shell and consists of six filtering cavities which are sequentially coupled along a first coupling path;

the second filtering branch is arranged on the shell and consists of five filtering cavities which are sequentially coupled along a second coupling path to form an inductive coupling zero point of the second filtering branch;

the third filtering branch is arranged on the shell and consists of eight filtering cavities which are sequentially coupled along a third coupling path to form two capacitive coupling zeros of the third filtering branch;

and the first common cavity is arranged on the shell and is respectively coupled with the first filtering cavity of the first filtering branch, the first filtering cavity of the second filtering branch and the first filtering cavity of the third filtering branch.

2. The filter according to claim 1, wherein the first to sixth filter cavities of the first filter branch and the second to fifth filter cavities of the second filter branch are divided into three rows arranged in sequence along the first direction;

the first filtering cavity, the second filtering cavity, the third filtering cavity and the fourth filtering cavity of the first filtering branch are in a row and are sequentially and adjacently arranged along the second direction, and the third filtering cavity and the fifth filtering cavity of the second filtering branch, the fifth filtering cavity and the sixth filtering cavity of the first filtering branch are in a row and are sequentially and adjacently arranged along the second direction; the first filter cavity of the first filter branch is respectively adjacent to the first common cavity, the third filter cavity of the second filter branch and the fifth filter cavity of the second filter branch;

the first common cavity, the first filter cavity of the second filter branch and the first to eighth filter cavities of the third filter branch are divided into two rows which are sequentially arranged along the first direction;

the first common cavity and the first filtering cavity to the fourth filtering cavity of the third filtering branch are in a row and are sequentially and adjacently arranged along the second direction; the first filtering cavity of the second filtering branch and the seventh filtering cavity to the fifth filtering cavity of the third filtering branch are in a row and are sequentially and adjacently arranged along the second direction; the first filter cavity of the third filter branch is respectively adjacent to the first filter cavity of the second filter branch and the eighth filter cavity of the third filter branch;

the projection of the center of the first filter cavity of the first filter branch in the first direction is located between the projection of the center of the first common cavity and the projection of the center of the third filter cavity of the second filter branch in the first direction, and the projection of the center of the first common cavity in the second direction is located between the projection of the center of the first filter cavity of the first filter branch and the projection of the center of the first filter cavity of the third filter branch in the second direction.

3. The filter according to claim 2, wherein the second filter cavity of the second filter branch and the fourth filter cavity of the second filter branch form an inductive cross-coupling therebetween, thereby forming an inductive coupling zero of the second filter branch;

capacitive cross coupling is respectively formed between a third filter cavity of the third filter branch and a sixth filter cavity of the third filter branch and between a fourth filter cavity of the third filter branch and the sixth filter cavity of the third filter branch, so that two capacitive coupling zeros of the third filter branch are formed.

4. The filter of claim 3, further comprising:

the fourth filtering branch is arranged on the shell and consists of six filtering cavities which are sequentially coupled along a fourth coupling path;

the fifth filtering branch is arranged on the shell and consists of five filtering cavities which are sequentially coupled along a fifth coupling path to form an inductive coupling zero point of the fifth filtering branch;

and the second common cavity is arranged on the shell and is respectively coupled with the first filtering cavity of the fourth filtering branch and the first filtering cavity of the fifth filtering branch.

5. The filter according to claim 4, wherein the second common cavity, the first to sixth filter cavities of the fourth filter branch, and the first to fifth filter cavities of the fifth filter branch are divided into four rows arranged in sequence along the first direction;

the fifth filtering cavity and the sixth filtering cavity of the fourth filtering branch are in a row and are sequentially and adjacently arranged along the second direction, the third filtering cavity and the fourth filtering cavity of the fourth filtering branch are in a row and are sequentially and adjacently arranged along the second direction, the second filtering cavity of the fourth filtering branch and the third filtering cavity of the fifth filtering branch are in a row and are sequentially and adjacently arranged along the second direction, and the first filtering cavity, the second filtering cavity, the fourth filtering cavity and the fifth filtering cavity of the second common cavity and the fifth filtering branch are in a row and are sequentially and adjacently arranged along the second direction;

the third filter cavity of the fourth filter branch is respectively adjacent to the fifth filter cavity of the fourth filter branch, the second filter cavity of the fourth filter branch and the third filter cavity of the fifth filter branch, and the second filter cavity of the fifth filter branch is respectively adjacent to the second filter cavity of the fourth filter branch and the third filter cavity of the fifth filter branch;

and the coupling zero distribution of the fifth filtering branch is the same as that of the second filtering branch.

6. The filter of claim 5, further comprising:

the sixth filtering branch is arranged on the shell and consists of eight filtering cavities which are sequentially coupled along a sixth coupling path to form two capacitive coupling zeros of the sixth filtering branch;

a third filtering cavity to an eighth filtering cavity of the sixth filtering branch are divided into four rows which are sequentially arranged along the first direction; the fifth filtering cavity, the sixth filtering cavity and the seventh filtering cavity of the sixth filtering branch are in a row and are sequentially and adjacently arranged along the second direction, and the fourth filtering cavity, the third filtering cavity and the eighth filtering cavity of the sixth filtering branch are in a row and are sequentially and adjacently arranged along the second direction; the third filter cavity of the sixth filter branch is respectively adjacent to the sixth filter cavity, the seventh filter cavity, the second filter cavity of the sixth filter branch and the first filter cavity of the fourth filter branch, and the second filter cavity of the sixth filter branch is also adjacent to the eighth filter cavity, the first filter cavity, the second common cavity and the first filter cavity of the fourth filter branch of the sixth filter branch; the projection of the first filter cavity of the sixth filter branch and the projection of the second common cavity in the first direction are overlapped, the projection of the second filter cavity of the sixth filter branch and the projection of the first filter cavity of the fourth filter branch in the first direction are overlapped, and the projection of the fourth filter cavity of the sixth filter branch and the projection of the third filter cavity of the fourth filter branch in the first direction are overlapped;

and the coupling zero distribution of the sixth filtering branch is the same as that of the third filtering branch.

7. The filter of claim 6, further comprising:

the seventh filtering branch is arranged on the shell and consists of eight filtering cavities which are sequentially coupled along a seventh coupling path to form two capacitive coupling zeros of the seventh filtering branch;

the first filtering cavity to the eighth filtering cavity of the seventh filtering branch circuit are divided into four rows which are sequentially arranged along the first direction; the first filtering cavities and the eighth filtering cavities of the seventh filtering branch are in a row and are sequentially and adjacently arranged along the second direction, the second filtering cavities and the seventh filtering cavities of the seventh filtering branch are in a row and are sequentially and adjacently arranged along the second direction, the third filtering cavities and the sixth filtering cavities of the seventh filtering branch are in a row and are sequentially and adjacently arranged along the second direction, and the fourth filtering cavities and the fifth filtering cavities of the seventh filtering branch are in a row and are sequentially and adjacently arranged along the second direction; the seventh filter cavity of the seventh filter branch is also respectively adjacent to the first filter cavity, the eighth filter cavity, the third filter cavity and the sixth filter cavity of the seventh filter branch, and the fourth filter cavity of the seventh filter branch is also adjacent to the seventh filter cavity and the sixth filter cavity of the third filter branch;

and the coupling zero distribution of the seventh filtering branch is the same as that of the third filtering branch.

8. The filter of claim 7, further comprising:

the eighth filtering branch is arranged on the shell and consists of eight filtering cavities which are sequentially coupled along an eighth coupling path to form two capacitive coupling zeros of the eighth filtering branch;

the second filtering cavity to the sixth filtering cavity of the eighth filtering branch are divided into two rows which are sequentially arranged along the first direction; the second filtering cavities, the third filtering cavities and the fourth filtering cavities of the eighth filtering branch are in a row and are sequentially and adjacently arranged along the second direction, and the sixth filtering cavities and the fifth filtering cavities of the eighth filtering branch are in a row and are sequentially and adjacently arranged along the second direction; the third filter cavity of the eighth filter branch is also respectively adjacent to the fifth filter cavity and the sixth filter cavity of the eighth filter branch, and the fifth filter cavity of the fifth filter branch, and the fifth filter cavity of the eighth filter branch is also adjacent to the fourth filter cavity of the eighth filter branch, and the fourth filter cavity and the sixth filter cavity of the fourth filter branch; the projection of the fourth filter cavity of the eighth filter branch and the projection of the third filter cavity of the fifth filter branch in the first direction are overlapped, and the projection of the fifth filter cavity of the eighth filter branch and the projection of the fourth filter cavity of the fourth filter branch in the first direction are overlapped;

the first filtering cavity, the second filtering cavity, the sixth filtering cavity, the seventh filtering cavity and the eighth filtering cavity of the eighth filtering branch are sequentially and adjacently arranged, and the distance between the projection of the center of the second filtering cavity, the center of the sixth filtering cavity, the center of the seventh filtering cavity and the center of the eighth filtering cavity of the eighth filtering branch in the first direction and the projection of the center of the first filtering cavity of the eighth filtering branch in the first direction is gradually increased; the projections of the seventh filter cavity and the eighth filter cavity of the eighth filter branch in the second direction are overlapped, and the projection of the center of the second filter cavity of the eighth filter branch in the second direction is located between the projection of the center of the first filter cavity of the eighth filter branch and the projection of the center of the third filter cavity of the eighth filter branch in the second direction;

and capacitive cross coupling is respectively performed between the third filtering cavity of the eighth filtering branch and the fifth filtering cavity of the eighth filtering branch and between the third filtering cavity of the eighth filtering branch and the sixth filtering cavity of the eighth filtering branch, so that two capacitive coupling zeros of the eighth filtering branch are formed.

9. The filter of claim 8, wherein the seventh filtering branch is arranged adjacent to the third filtering branch along the first direction;

the first filtering branch, the second filtering branch, the third filtering branch and the seventh filtering branch are arranged in a first area of the shell, the fourth filtering branch, the fifth filtering branch, the sixth filtering branch and the eighth filtering branch are arranged in a second area of the shell, and the first area and the second area are arranged at intervals.

10. A communication device, characterized in that the communication device comprises an antenna and a radio frequency unit connected to the antenna, the radio frequency unit comprising a filter according to any of claims 1-9 for filtering a radio frequency signal.

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