CN113054348A

CN113054348A - Communication system and filter thereof

Info

Publication number: CN113054348A
Application number: CN201911380990.5A
Authority: CN
Inventors: 温世议; 张海峰; 周峰; 汪俊
Original assignee: Shenzhen Tatfook Technology Co Ltd
Current assignee: Shenzhen Tatfook Technology Co Ltd
Priority date: 2019-12-27
Filing date: 2019-12-27
Publication date: 2021-06-29

Abstract

The application discloses a communication system and a filter thereof. The filter includes: the first port, the second port and a first common cavity connected with the first port are arranged on the shell; the first filtering branch is coupled with the first port and consists of ten filtering cavities which are sequentially coupled, and five cross-coupling zero points are further formed by the ten filtering cavities of the first filtering branch; the second filtering branch circuit is respectively coupled with the first common cavity and the second port and consists of eight filtering cavities which are sequentially coupled, and the eight filtering cavities of the second filtering branch circuit further form three cross-coupling zeros; the third filtering branch circuit is respectively coupled with the first common cavity and the second port and consists of five filtering cavities which are sequentially coupled, and the five filtering cavities of the third filtering branch circuit further form two cross-coupling zero points; through the mode, the number of taps can be reduced due to the arrangement of the common cavity and the common port, the size of the filter is reduced, zero point suppression can be realized through the cross coupling zero point, and the index debugging is facilitated.

Description

Communication system and filter thereof

Technical Field

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

Background

In a mobile communication system, a desired signal is modulated to form a modulated signal, the modulated signal is carried on a high-frequency carrier signal, the modulated signal is transmitted to the air through a transmitting antenna, the signal in the air is received through a receiving antenna, and the signal received by the receiving antenna does not include the desired signal but also includes harmonics and noise signals of other frequencies. The signal received by the receiving antenna needs to be filtered by a filter to remove unnecessary harmonic and noise signals. Therefore, the designed filter must precisely control its bandwidth.

The inventor of the application finds that in long-term research and development work, in order to reduce the size of the filter, the filter is generally provided with two or more groups of filter branches with different frequencies, but each filter branch in the prior art needs to be provided with a tap independently, and the number of the taps is too large, so that the required welding points are too many, the size of the filter is not reduced, and the stability of the filter is influenced; the existing filter has poor performances such as out-of-band rejection and the like, and high isolation among filtering branches with different frequencies is difficult to achieve.

Disclosure of Invention

The application provides a filter to it is too much to solve the quantity that prior art's filter was tapped, leads to required welding point also more, and performance such as outband suppression is relatively poor, accomplishes the technical problem of the high isolation between the filtering branch road of different frequencies very difficultly.

To solve the above problem, an embodiment of the present application provides a filter, where the filter includes: a housing having a first direction and a second direction perpendicular to each other;

the first port, the second port and a first common cavity connected with the first port are arranged on the shell;

the first filtering branch is coupled with the first port and consists of ten filtering cavities which are sequentially coupled, and five cross-coupling zero points are further formed by the ten filtering cavities of the first filtering branch;

the second filtering branch circuit is respectively coupled with the first common cavity and the second port and consists of eight filtering cavities which are sequentially coupled, and the eight filtering cavities of the second filtering branch circuit further form three cross-coupling zero points;

and the third filtering branch circuit is coupled with the first common cavity and the second port respectively and consists of five filtering cavities which are sequentially coupled, and the five filtering cavities of the third filtering branch circuit further form two cross-coupling zero points.

In order to solve the above problem, an embodiment of the present application provides a communication system, where the communication system includes an antenna and a radio frequency unit connected to the antenna, and the radio frequency unit includes the filter as described above and is configured to filter a radio frequency signal.

Compared with the prior art, the filter of this application includes: a housing having a first direction and a second direction perpendicular to each other; the first port, the second port and a first common cavity connected with the first port are arranged on the shell; the first filtering branch is coupled with the first port and consists of ten filtering cavities which are sequentially coupled, and five cross-coupling zero points are further formed by the ten filtering cavities of the first filtering branch; the second filtering branch circuit is respectively coupled with the first common cavity and the second port and consists of eight filtering cavities which are sequentially coupled, and the eight filtering cavities of the second filtering branch circuit further form three cross-coupling zeros; the third filtering branch circuit is respectively coupled with the first common cavity and the second port and consists of five filtering cavities which are sequentially coupled, and the five filtering cavities of the third filtering branch circuit further form two cross-coupling zero points; in this way, the filter of this application sets up first port and second port as the common port to and first public chamber can reduce the quantity of taking a percentage, reduces required welding point, reduces the filter volume, and the debugging and reduction in production cost of being convenient for, the isolation is high between the filtering branch road, can reduce the product complexity, improves the stability of filter, and cross coupling zero point can realize the suppression of zero point, and the debugging index of being convenient for reaches the design requirement.

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 provided herein;

fig. 2 is a schematic diagram of a topology of a first filtering branch provided in the present application;

fig. 3 is a schematic diagram of a topology of a second filtering branch provided in the present application;

fig. 4 is a schematic diagram of a topology of a third filtering branch provided in the present application;

FIG. 5 is a schematic diagram of another embodiment of a filter provided herein;

fig. 6 is a schematic diagram of a topology of a fourth filtering branch provided in the present application;

fig. 7 is a schematic diagram of a topology of a fifth filtering branch provided in the present application;

fig. 8 is a schematic diagram of a topology of a sixth filtering branch provided in the present application;

FIG. 9 is a schematic diagram of a filter according to another embodiment of the present application;

fig. 10 is a schematic diagram of a topology of a seventh filtering branch provided in the present application;

fig. 11 is a schematic diagram of a topology of an eighth filtering branch provided in the present application;

fig. 12 is a schematic diagram of a topology of a ninth filtering branch provided in the present application;

fig. 13 is a schematic diagram of a topology of a tenth filtering branch provided in the present application;

fig. 14 is a schematic diagram of a topology of an eleventh filtering branch provided in the present application;

fig. 15 is a schematic diagram of a topology of a twelfth filtering branch provided in the present application;

FIG. 16 is a diagram illustrating a first simulation result of the filter provided herein;

FIG. 17 is a diagram illustrating a second simulation result of the filter provided herein;

fig. 18 is a schematic structural diagram of an embodiment of a communication system provided in the present application.

Detailed Description

The present application will be described in further detail with reference to the following drawings and examples. It is to be noted that the following examples are only illustrative of the present application, and do not limit the scope of the present application. Likewise, the following examples are only some examples and not all examples of the present application, and all other examples obtained by a person of ordinary skill in the art without any inventive step are within the scope of the present application.

The terms "first," "second," "third," "fourth," and the like in the description and in the claims of the present application and in the drawings described above, if any, are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used is interchangeable under appropriate circumstances such that the embodiments of the application described herein are, for example, capable of operation in sequences other than those illustrated or otherwise described herein. Furthermore, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or system that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed, but may include other steps or elements not expressly listed or inherent to such process, method, article, or system.

The present application provides a filter, as shown in fig. 1, fig. 1 is a schematic structural diagram of an embodiment of the filter of the present application. The filter 10 of the present embodiment includes a housing 11, a first port 12, a second port 13, and a first common chamber 14 connected to the first port 12, and is disposed on the housing 11; a first filter branch 15, a second filter branch 16 and a third filter branch 17 are also included. The first filtering branch 15, the second filtering branch 16 and the third filtering branch 17 may be a receiving filtering branch and a transmitting filtering branch, respectively, or may also be a receiving filtering branch or a transmitting filtering branch. The housing 11 has a first direction L and a second direction D, and the first direction L of the housing 11 is perpendicular to the second direction D of the housing 11.

The first filtering branch 15 is coupled to the first port 12, and is composed of ten filtering cavities coupled in sequence, and the ten filtering cavities of the first filtering branch 15 further form five cross-coupling zeros 151.

And a second filtering branch 16, which is respectively coupled to the first common cavity 14 and the second port 13 and is composed of eight filtering cavities coupled in sequence, wherein the eight filtering cavities of the second filtering branch 16 further form three cross-coupling zeros 161.

And a third filtering branch 17, which is respectively coupled to the first common cavity 14 and the second port 13 and is composed of five filtering cavities coupled in sequence, wherein the five filtering cavities of the third filtering branch 17 further form two cross-coupling zeros 171.

In this embodiment, the first filtering cavity B1 of the second filtering branch 16 and the first filtering cavity C1 of the third filtering branch 17 are coupled to the first common cavity 14, the first common cavity 14 and the tenth filtering cavity a10 of the first filtering branch 15 are connected to the first port 12, and the eighth filtering cavity B8 of the second filtering branch 16 and the fifth filtering cavity C5 of the third filtering branch 17 are connected to the second port 13, so that the number of taps of the filter 10 can be reduced, the required welding points can be reduced, and the size of the filter 10 can be reduced.

Ten filter cavities of the first filter branch 15, eight filter cavities of the second filter branch 16, five filter cavities of the third filter branch 17 and the first common cavity 14 are divided into six rows arranged along the first direction L; the second filtering cavity a2, the first filtering cavity a1, the ninth filtering cavity a9 and the tenth filtering cavity a10 of the first filtering branch 15 are in a row and are sequentially arranged along the second direction D; the third filtering cavity A3, the sixth filtering cavity a6, the eighth filtering cavity A8 and the first common cavity 14 of the first filtering branch 15 are in a row and are sequentially arranged along the second direction D; the fourth filtering cavity a4, the fifth filtering cavity a5, the seventh filtering cavity a7 of the first filtering branch 15, the first filtering cavity B1 of the second filtering branch 16 and the first filtering cavity C1 of the third filtering branch 17 are in a row and are sequentially arranged along the second direction D; the fourth filtering cavity B4, the third filtering cavity B3, the second filtering cavity B2 of the second filtering branch 16, the fourth filtering cavity C4 and the second filtering cavity C2 of the third filtering branch 17 are in a row and are sequentially arranged along the second direction D; the fifth filtering cavity B5, the sixth filtering cavity B6, the seventh filtering cavity B7 of the second filtering branch 16, and the fifth filtering cavity C5 and the third filtering cavity C3 of the third filtering branch 17 are in a row and are sequentially arranged along the second direction D.

Further, the third filtering cavity A3 of the first filtering branch 15 is respectively adjacent to the first filtering cavity a1, the second filtering cavity a2, the fourth filtering cavity a4, the fifth filtering cavity a5 and the sixth filtering cavity a 6; the eighth filtering cavity A8 of the first filtering branch 15 is respectively adjacent to the sixth filtering cavity a6, the seventh filtering cavity a7, the ninth filtering cavity a9, the tenth filtering cavity a10, the first common cavity 14 and the first filtering cavity B1 of the second filtering branch 16; the fourth filtering cavity B4 of the second filtering branch 16 is respectively adjacent to the third filtering cavity B3, the fifth filtering cavity B5, the sixth filtering cavity B6, the fourth filtering cavity a4 and the fifth filtering cavity a5 of the first filtering branch 15; the second filtering cavity B2 of the second filtering branch 16 is respectively adjacent to the first filtering cavity B1, the third filtering cavity B3, the seventh filtering cavity B7, the seventh filtering cavity a7 of the first filtering branch 15, the fourth filtering cavity C4 and the fifth filtering cavity C5 of the third filtering branch 17; the second filtering cavity C2 of the third filtering branch 17 is respectively adjacent to the first filtering cavity C1, the third filtering cavity C3 and the fourth filtering cavity C4; the eighth filter chamber B8 of the second filter branch 16 is arranged adjacent to the sixth filter chamber B6 and the seventh filter chamber B7, respectively.

Wherein, ten filtering cavities of first filtering branch 15, eight filtering cavities of second filtering branch 16 and five filtering cavities of third filtering branch 17 are regularly arranged, can save the space in casing 11, are favorable to reducing the volume of wave filter 10, improve wave filter 10's stability. Further, the ten filter cavities of the first filter branch 15, the eight filter cavities of the second filter branch 16, and the five filter cavities of the third filter branch 17 are all the same in size, so that the first filter cavity a1 to the tenth filter cavity a10 of the first filter branch 15, the first filter cavity B1 to the eighth filter cavity B8 of the second filter branch 16, and the first filter cavity C1 to the fifth filter cavity C5 of the third filter branch 17 in the housing 11 may be distributed and disposed at equal intervals, and the distances between the centers of any two adjacent filter cavities are all equal, so that the arrangement is tight, the layout and debugging are facilitated, and the consistency of the filter 10 is improved.

Further, as shown in fig. 2, the fifth filtering cavity a5 and the eighth filtering cavity A8, the eighth filtering cavity A8 and the tenth filtering cavity a10 of the first filtering branch 15 are inductively cross-coupled, respectively, the second filtering cavity a2 and the fifth filtering cavity a5, the third filtering cavity A3 and the fifth filtering cavity a5, and the sixth filtering cavity a6 and the eighth filtering cavity A8 are capacitively cross-coupled, respectively, so as to form five cross-coupling zeros 151 of the first filtering branch 15, respectively, such as inductors L1, L2, capacitors C1, C2, and C3 shown in fig. 2. The zero point suppression can be realized by setting the cross-coupling zero point 151 of the first filtering branch 15, so that the debugging index is facilitated, and the design requirement is met.

Specifically, a window may be disposed between the fifth filter cavity a5 and the eighth filter cavity A8 of the first filter branch 15, and a metal coupling rib is disposed on the window, so that the fifth filter cavity a5 and the eighth filter cavity A8 are inductively cross-coupled to form an inductor L1. A window may be disposed between the eighth filtering cavity A8 and the tenth filtering cavity a10 of the first filtering branch 15, and a metal coupling rib is disposed on the window, so that the eighth filtering cavity A8 and the tenth filtering cavity a10 are inductively cross-coupled to form an inductor L2. A window may be disposed between the second filtering cavity a2 and the fifth filtering cavity a5 of the first filtering branch 15, and a capacitive flying bar is disposed at the window, so that capacitive cross coupling is achieved between the second filtering cavity a2 and the fifth filtering cavity a5, and a capacitor C1 is formed. A window may be disposed between the third filtering cavity A3 and the fifth filtering cavity a5 of the first filtering branch 15, and a capacitive flying bar is disposed at the window, so that capacitive cross coupling is achieved between the third filtering cavity A3 and the fifth filtering cavity a5, and a capacitor C2 is formed. A window may be disposed between the sixth filtering cavity a6 and the eighth filtering cavity A8 of the first filtering branch 15, and a capacitive flying rod is disposed at the window, so that capacitive cross coupling is achieved between the sixth filtering cavity a6 and the eighth filtering cavity A8, and a capacitor C3 is formed. 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 as to prevent the filter 10 from generating the temperature drift.

As shown in fig. 3, capacitive cross coupling is performed between the third filter cavity B3 and the sixth filter cavity B6, between the fourth filter cavity B4 and the sixth filter cavity B6, and inductive cross coupling is performed between the sixth filter cavity B6 and the eighth filter cavity B8 of the second filter branch 16, so as to form three cross-coupling zeros 161 of the second filter branch 16, such as capacitors C1, C2, and inductor L1 shown in fig. 3. The zero point suppression can be realized by the arrangement of the cross-coupling zero point 161 of the second filtering branch 16, so that the debugging index is facilitated, and the design requirement is met.

Specifically, a window may be disposed between the third filter cavity B3 and the sixth filter cavity B6 of the second filter branch 16, and a capacitive fly rod may be disposed at the window, so that capacitive cross coupling is achieved between the third filter cavity B3 and the sixth filter cavity B6, and a capacitor C1 is formed. A window may be disposed between the fourth filter cavity B4 and the sixth filter cavity B6 of the second filter branch 16, and a capacitive fly rod may be disposed at the window, so that capacitive cross coupling is achieved between the fourth filter cavity B4 and the sixth filter cavity B6, and a capacitor C2 is formed. A window may be disposed between the sixth filtering cavity B6 and the eighth filtering cavity B8 of the second filtering branch 16, and a metal coupling rib is disposed on the window, so that the sixth filtering cavity B6 and the eighth filtering cavity B8 realize inductive cross coupling, and an inductor L1 is formed. 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 as to prevent the filter 10 from generating the temperature drift.

As shown in fig. 4, the first filter cavity C1 of the third filter branch 17 is capacitively cross-coupled with the fourth filter cavity C4, and the second filter cavity C2 is inductively cross-coupled with the fourth filter cavity C4, so as to form two cross-coupling zeros 171 of the third filter branch 17, such as the capacitor C1 and the inductor L1 shown in fig. 4. The zero point suppression can be realized by the arrangement of the cross-coupling zero point 171 of the third filtering branch 17, so that the debugging index is convenient, and the design requirement is met.

Specifically, a window may be disposed between the first filtering cavity C1 and the fourth filtering cavity C4 of the third filtering branch 17, and a capacitive fly rod may be disposed at the window, so that capacitive cross coupling is achieved between the first filtering cavity C1 and the fourth filtering cavity C4, and a capacitor C1 is formed. A window may be disposed between the second filter cavity C2 and the fourth filter cavity C4 of the third filter branch 17, and a metal coupling rib is disposed on the window, so that the inductive cross coupling is implemented between the second filter cavity C2 and the fourth filter cavity C4, and an inductor L1 is formed. 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 as to prevent the filter 10 from generating the temperature drift.

The coupling zero is also referred to as a transmission zero. The transmission zero is the transmission function of the filter 10 equal to zero, that is, the electromagnetic energy cannot pass through the network at the frequency point corresponding to the transmission zero, so that the complete isolation effect is achieved, the inhibition effect on signals outside the band-pass is achieved, and the high isolation among a plurality of band-passes can be better achieved.

In this embodiment, the first filtering cavity B1 of the second filtering branch 16 and the first filtering cavity C1 of the third filtering branch 17 are coupled to the first common cavity 14, the first common cavity 14 and the tenth filtering cavity a10 of the first filtering branch 15 are connected to the first port 12, and the eighth filtering cavity B8 of the second filtering branch 16 and the fifth filtering cavity C5 of the third filtering branch 17 are connected to the second port 13, so that the number of taps of the filter 10 can be reduced, the required welding points can be reduced, and the size of the filter 10 can be reduced; ten filter cavities of the first filter branch 15, eight filter cavities of the second filter branch 16 and five filter cavities of the third filter branch 17 are regularly arranged, so that the space in the shell 11 can be saved, the size of the filter 10 can be reduced, and the stability of the filter 10 can be improved. Furthermore, the ten filter cavities of the first filter branch 15, the eight filter cavities of the second filter branch 16 and the five filter cavities of the third filter branch 17 are all the same in size, so that the first filter cavity a1 to the tenth filter cavity a10 of the first filter branch 15, the first filter cavity B1 to the eighth filter cavity B8 of the second filter branch 16 and the first filter cavity C1 to the fifth filter cavity C5 of the third filter branch 17 in the housing 11 can be distributed and arranged equidistantly, the distances between the centers of any two adjacent filter cavities are all the same, the arrangement is tight, the layout and debugging are facilitated, and the consistency of the filter 10 is improved; the zero point suppression can be realized by the arrangement of the cross coupling zero point 151 of the first filtering branch 15, the cross coupling zero point 161 of the second filtering branch 16 and the cross coupling zero point 171 of the third filtering branch 17, so that the debugging index is convenient, and the design requirement is met; 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 as to prevent the filter 10 from generating the temperature drift.

Referring to fig. 5, fig. 5 is a schematic structural diagram of another embodiment of the filter of the present application. The filter 10 of the present embodiment further includes, on the basis of the embodiment shown in fig. 1:

a third port 22, a fourth port 23 and a second common chamber 24 connected to the third port 22 are provided on the housing 11.

And a fourth filtering branch 25, coupled to the third port 22, and composed of ten filtering cavities coupled in sequence, where the ten filtering cavities of the fourth filtering branch 25 further form five cross-coupling zeros 251.

And a fifth filtering branch 26, which is respectively coupled to the second common cavity 24 and the fourth port 23, and is composed of eight filtering cavities coupled in sequence, wherein the eight filtering cavities of the fifth filtering branch 26 further form three cross-coupling zeros 261.

And a sixth filtering branch 27, which is respectively coupled to the second common cavity 24 and the fourth port 23, and is composed of five filtering cavities that are sequentially coupled, where the five filtering cavities of the sixth filtering branch 27 further form two cross-coupling zeros 271.

In this embodiment, the first filter cavity E1 of the fifth filter branch 26 and the first filter cavity F1 of the sixth filter branch 27 are coupled to the second common cavity 24, the tenth filter cavity D10 of the second common cavity 24 and the fourth filter branch 25 are connected to the third port 22, and the eighth filter cavity E8 of the fifth filter branch 26 and the fifth filter cavity F5 of the sixth filter branch 27 are connected to the fourth port 23, so that the number of taps of the filter 10 can be reduced, the required welding points can be reduced, and the size of the filter 10 can be reduced.

Wherein, ten filter cavities of the fourth filter branch 25, eight filter cavities of the fifth filter branch 26, five filter cavities of the sixth filter branch 27, and the second common cavity 24 are divided into six rows arranged along the second direction D; the sixth filtering cavity E6, the seventh filtering cavity E7 and the eighth filtering cavity E8 of the fifth filtering branch 26 are in a row and are sequentially arranged along the first direction L; the fifth filter cavity E5, the fourth filter cavity E4 of the fifth filter branch 26, the fifth filter cavity F5, the third filter cavity F3 and the second filter cavity F2 of the sixth filter branch 27 are in a row and are sequentially arranged along the first direction L; the third filter cavity E3, the second filter cavity E2 of the fifth filter branch 26, the fourth filter cavity F4 and the first filter cavity F1 of the sixth filter branch 27 are in a row and are sequentially arranged along the first direction L; the first filter cavity D1, the second filter cavity D2, the sixth filter cavity D6 of the fourth filter branch 25, and the first filter cavity E1 and the second common cavity 24 of the fifth filter branch 26 are in a row and are sequentially arranged along the first direction L; the third filter cavity D3, the fifth filter cavity D5, the seventh filter cavity D7 and the tenth filter cavity D10 of the fourth filter branch 25 are in a row and are sequentially arranged along the first direction L; the fourth filter cavity D4, the eighth filter cavity D8 and the ninth filter cavity D9 of the fourth filter branch 25 are in a row and are sequentially arranged along the first direction L.

Further, the third filtering cavity D3 of the fourth filtering branch 25 is respectively disposed adjacent to the first filtering cavity D1, the second filtering cavity D2, the fourth filtering cavity D4 and the fifth filtering cavity D5; the seventh filtering cavity D7 of the fourth filtering branch 25 is respectively adjacent to the sixth filtering cavity D6, the fifth filtering cavity D5, the eighth filtering cavity D8, the ninth filtering cavity D9, the tenth filtering cavity D10 and the first filtering cavity E1 of the fifth filtering branch 26; the first filtering cavity E1 of the fifth filtering branch 26 is respectively adjacent to the second filtering cavity E2, the fourth filtering cavity F4 of the sixth filtering branch 27, the second common cavity 24, the sixth filtering cavity D6 of the fourth filtering branch 25, the seventh filtering cavity D7 and the tenth filtering cavity D10; the third filter cavity F3 of the sixth filter branch 27 is respectively adjacent to the first filter cavity F1, the second filter cavity F2, the fourth filter cavity F4 and the fifth filter cavity F5; the fourth filter cavity E4 of the fifth filter branch 26 is respectively adjacent to the second filter cavity E2, the third filter cavity E3, the fifth filter cavity E5, the seventh filter cavity E7, the eighth filter cavity E8 and the fifth filter cavity F6 of the sixth filter branch 27.

Wherein, ten filter chambers of fourth filter branch 25, eight filter chambers of fifth filter branch 26 and five filter chambers of sixth filter branch 27 are regularly arranged, so that the space in housing 11 can be saved, the volume of filter 10 can be reduced, and the stability of filter 10 can be improved. Further, the ten filter cavities of the fourth filter branch 25, the eight filter cavities of the fifth filter branch 26, and the five filter cavities of the sixth filter branch 27 are all the same in size, so that the first filter cavity D1 to the tenth filter cavity D10 of the fourth filter branch 25, the first filter cavity E1 to the eighth filter cavity E8 of the fifth filter branch 26, and the first filter cavity F1 to the fifth filter cavity F5 of the sixth filter branch 27 in the housing 11 may be distributed and disposed at equal intervals, and the distances between the centers of any two adjacent filter cavities are all equal, and the arrangement is tight, so that the layout and debugging are facilitated, and the consistency of the filter 10 is improved.

As shown in fig. 6, the first filtering cavity D1 and the fourth filtering cavity D4, the second filtering cavity D2 and the fourth filtering cavity D4, the fourth filtering cavity D4 and the sixth filtering cavity D6, the sixth filtering cavity D6 and the eighth filtering cavity D8, and the sixth filtering cavity D6 and the ninth filtering cavity D9 of the fourth filtering branch 25 are respectively cross-coupled in a capacitive manner to form five cross-coupling zeros 251 of the fourth filtering branch 25, which are respectively shown as capacitors C1, C2, C3, C4, and C5 in fig. 6. The zero point suppression can be realized by setting the cross-coupling zero point 251 of the fourth filtering branch 25, so that the debugging index is facilitated, and the design requirement is met. Moreover, the fourth filtering branch 25 has good consistency of single-capacity materials and high product stability.

Specifically, a window may be disposed between the first filtering cavity D1 and the fourth filtering cavity D4 of the fourth filtering branch 25, and a capacitive fly rod is disposed at the window, so that capacitive cross coupling is achieved between the first filtering cavity D1 and the fourth filtering cavity D4, and a capacitor C1 is formed. A window may be disposed between the second filtering cavity D2 and the fourth filtering cavity D4 of the fourth filtering branch 25, and a capacitive flying bar is disposed at the window, so that capacitive cross coupling is achieved between the second filtering cavity D2 and the fourth filtering cavity D4, and a capacitor C2 is formed. A window may be disposed between the fourth filter cavity D4 and the sixth filter cavity D6 of the fourth filter branch 25, and a capacitive flying rod is disposed at the window, so that capacitive cross coupling is achieved between the fourth filter cavity D4 and the sixth filter cavity D6, and a capacitor C3 is formed. A window may be disposed between the sixth filtering cavity D6 and the eighth filtering cavity D8 of the fourth filtering branch 25, and a capacitive flying rod is disposed at the window, so that capacitive cross coupling is achieved between the sixth filtering cavity D6 and the eighth filtering cavity D8, and a capacitor C4 is formed. A window may be disposed between the sixth filtering cavity D6 and the ninth filtering cavity D9 of the fourth filtering branch 25, and a capacitive flying rod is disposed at the window, so that capacitive cross coupling is achieved between the sixth filtering cavity D6 and the ninth filtering cavity D9, and a capacitor C5 is formed.

As shown in fig. 7, the second filter cavity E2 and the fourth filter cavity E4 of the fifth filter branch 26 are inductively cross-coupled, the fourth filter cavity E4 and the seventh filter cavity E7 are capacitively cross-coupled, and the fifth filter cavity E5 and the seventh filter cavity E7 are capacitively cross-coupled, respectively, to form three cross-coupled zeros 261 of the fifth filter branch 26, such as an inductor L1, a capacitor C1, and a capacitor C2 shown in fig. 7. The zero point suppression can be realized by setting the cross-coupling zero point 261 of the fifth filtering branch 26, so that the debugging index is facilitated, and the design requirement is met.

Specifically, a window may be disposed between the second filter cavity E2 and the fourth filter cavity E4 of the fifth filter branch 26, and a metal coupling rib is disposed on the window, so that inductive cross coupling is achieved between the second filter cavity E2 and the fourth filter cavity E4, and an inductance L1 is formed. A window may be disposed between the fourth filter cavity E4 and the seventh filter cavity E7 of the fifth filter branch 26, and a capacitive fly rod is disposed at the window, so that capacitive cross coupling is achieved between the fourth filter cavity E4 and the seventh filter cavity E7, and a capacitor C1 is formed. A window may be disposed between the fifth filter cavity E5 and the seventh filter cavity E7 of the fifth filter branch 26, and a capacitive fly rod may be disposed at the window, so that capacitive cross coupling is achieved between the fifth filter cavity E5 and the seventh filter cavity E7, and a capacitor C2 is formed.

As shown in fig. 8, the first filter cavity F1 of the sixth filter branch 27 is capacitively cross-coupled with the fourth filter cavity F4, and the first filter cavity F1 is inductively cross-coupled with the third filter cavity F3, so as to form two cross-coupling zeros 271 of the sixth filter branch 27, such as the capacitor C1 and the inductor L1 shown in fig. 8. The zero point suppression can be realized by the arrangement of the cross-coupling zero point 271 of the sixth filtering branch 27, so that the debugging index is facilitated, and the design requirement is met.

Specifically, a window may be disposed between the first filtering cavity F1 and the fourth filtering cavity F4 of the sixth filtering branch 27, and a capacitive fly rod is disposed at the window, so that capacitive cross coupling is achieved between the first filtering cavity F1 and the fourth filtering cavity F4, and a capacitor C1 is formed. A window may be disposed between the first filter cavity F1 and the third filter cavity F3 of the sixth filter branch 27, and a metal coupling rib is disposed on the window, so that the inductive cross coupling is achieved between the first filter cavity F1 and the third filter cavity F3, and an inductor L1 is formed. 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 as to prevent the filter 10 from generating the temperature drift.

Referring to fig. 9, fig. 9 is a schematic structural diagram of another embodiment of the filter of the present application. The filter 10 of the present embodiment further includes, on the basis of the embodiment shown in fig. 5:

a fifth port 32, a sixth port 33, and a third common chamber 34 connected to the fifth port 32 are provided on the housing 11.

And a seventh filtering branch 35, coupled to the fifth port 32, and composed of ten filtering cavities coupled in sequence, where the ten filtering cavities of the seventh filtering branch 35 further form five cross-coupling zeros 351.

And an eighth filtering branch 36, respectively coupled to the third common cavity 34 and the sixth port 33, and composed of eight filtering cavities coupled in sequence, where the eight filtering cavities of the eighth filtering branch 36 further form three cross-coupling zeros 361.

And a ninth filtering branch 37, respectively coupled to the third common cavity 34 and the sixth port 33, and composed of five filtering cavities coupled in sequence, where the five filtering cavities of the ninth filtering branch 37 further form two cross-coupling zeros 371.

In this embodiment, the first filtering cavity H1 of the eighth filtering branch 36 and the first filtering cavity I1 of the ninth filtering branch 37 are coupled to the third common cavity 34, the tenth filtering cavity G10 of the third common cavity 34 and the seventh filtering branch 35 are connected to the fifth port 32, and the eighth filtering cavity H8 of the eighth filtering branch 36 and the fifth filtering cavity I5 of the ninth filtering branch 37 are connected to the sixth port 33, so that the number of taps of the filter 10 can be reduced, the number of required welding points can be reduced, and the size of the filter 10 can be reduced.

A seventh port 42, an eighth port 43, and a fourth common chamber 44 connected to the seventh port 42 are provided on the housing 11.

And a tenth filtering branch 45, coupled to the seventh port 42, and composed of ten filtering cavities coupled in sequence, where the ten filtering cavities of the tenth filtering branch 45 further form five cross-coupling zeros 451.

And an eleventh filtering branch 46, respectively coupled to the fourth common cavity 44 and the eighth port 43, and composed of eight filtering cavities coupled in sequence, where the eight filtering cavities of the eleventh filtering branch 46 further form three cross-coupling zeros 461.

And a twelfth filtering branch 47, respectively coupled to the fourth common cavity 44 and the eighth port 43, and composed of five filtering cavities coupled in sequence, where the five filtering cavities of the twelfth filtering branch 47 further form two cross-coupling zeros 471.

In this embodiment, the first filter cavity K1 of the eleventh filter branch 46 and the first filter cavity L1 of the twelfth filter branch 47 are coupled to the fourth common cavity 44, the fourth common cavity 44 and the tenth filter cavity J10 of the tenth filter branch 45 are connected to the seventh port 42, and the eighth filter cavity K8 of the eleventh filter branch 46 and the fifth filter cavity L5 of the twelfth filter branch 47 are connected to the eighth port 43, so that the number of taps of the filter 10 can be reduced, the number of required welding points can be reduced, and the size of the filter 10 can be reduced.

Wherein, the ten filter cavities of the seventh filter branch 35, the eight filter cavities of the eighth filter branch 36, the five filter cavities of the ninth filter branch 37, and the third common cavity 34 are divided into six rows arranged along the second direction D; the third filtering cavity H3, the fourth filtering cavity H4, the sixth filtering cavity H6 and the seventh filtering cavity H7 of the eighth filtering branch 36 are in a row and are sequentially arranged along the first direction L; the second filtering cavity H2, the first filtering cavity H1, the fifth filtering cavity H5 and the eighth filtering cavity H8 of the eighth filtering branch 36 are in a row and are sequentially arranged along the first direction L; the third common cavity 34, the first filter cavity I1, the fifth filter cavity I5 and the fourth filter cavity I4 of the ninth filter branch 37 are in a row and are sequentially arranged along the first direction L; the ninth filtering cavity G9, the tenth filtering cavity G10, the sixth filtering cavity G6 of the seventh filtering branch 35, and the second filtering cavity I2 and the third filtering cavity I3 of the ninth filtering branch 37 are in a row and are sequentially arranged along the first direction L; the eighth filtering cavity G8, the seventh filtering cavity G7, the fifth filtering cavity G5 and the fourth filtering cavity G4 of the seventh filtering branch 35 are in a row and are sequentially arranged along the first direction L; the first filter cavity G1, the second filter cavity G2, and the third filter cavity G3 of the seventh filter branch 35 are in a row and are sequentially arranged along the first direction L.

Further, the first filtering cavity H1 of the eighth filtering branch 36 is respectively disposed adjacent to the second filtering cavity H2, the third filtering cavity H3, the fourth filtering cavity H4, the fifth filtering cavity H5 and the third common cavity 34; the eighth filtering cavity H8 of the eighth filtering branch 36 is respectively adjacent to the fifth filtering cavity H5, the sixth filtering cavity H6, the seventh filtering cavity H7 and the fifth filtering cavity I5 of the ninth filtering branch 37; the first filter cavity I5 of the ninth filter branch 37 is respectively adjacent to the second filter cavity I2, the fifth filter cavity I5, the fifth filter cavity H5 of the eighth filter branch 36, the third common cavity 34 and the sixth filter cavity G6 of the seventh filter branch 35; the tenth filtering cavity G10 of the seventh filtering branch 35 is respectively adjacent to the ninth filtering cavity G9, the eighth filtering cavity G8, the seventh filtering cavity G7, the sixth filtering cavity G6 and the third common cavity 34; the fifth filtering cavity G5 of the seventh filtering branch 35 is respectively adjacent to the fourth filtering cavity G4, the second filtering cavity G2, the first filtering cavity G1, the seventh filtering cavity G7, the sixth filtering cavity G6 and the second filtering cavity I2 of the ninth filtering branch 37.

Wherein, ten filter chambers of seventh filtering branch 35, eight filter chambers of eighth filtering branch 36 and five filter chambers of ninth filtering branch 37 are regularly arranged, can save the space in casing 11, are favorable to reducing the volume of wave filter 10, improve wave filter 10's stability. Further, the ten filter cavities of the seventh filter branch 35, the eight filter cavities of the eighth filter branch 36, and the five filter cavities of the ninth filter branch 37 are all the same in size, so that the first filter cavity G1 to the tenth filter cavity G10 of the seventh filter branch 35, the first filter cavity H1 to the eighth filter cavity H8 of the eighth filter branch 36, and the first filter cavity I1 to the fifth filter cavity I5 of the ninth filter branch 37 in the housing 11 may be distributed and disposed at equal intervals, and the distances between the centers of any two adjacent filter cavities are all equal, and the arrangement is tight, so that the layout and debugging are facilitated, and the consistency of the filter 10 is improved.

As shown in fig. 10, the capacitors C1, C2, C3, C4 and C5 of the seventh filtering branch 35 are respectively formed by capacitive cross-coupling between the first filtering cavity G1 and the third filtering cavity G3, between the first filtering cavity G1 and the fourth filtering cavity G4, between the fourth filtering cavity G4 and the sixth filtering cavity G6, between the sixth filtering cavity G6 and the ninth filtering cavity G9, and between the seventh filtering cavity G7 and the ninth filtering cavity G9 of the seventh filtering branch 35, respectively, as shown in fig. 10. The zero point suppression can be realized by setting the cross-coupling zero point 351 of the seventh filtering branch 35, so that the debugging index is convenient, and the design requirement is met. Moreover, the seventh filtering branch 35 has good consistency of single-capacitance materials and high product stability.

Specifically, a window may be disposed between the first filtering cavity G1 and the third filtering cavity G3 of the seventh filtering branch 35, and a capacitive fly rod is disposed at the window, so that capacitive cross coupling is achieved between the first filtering cavity G1 and the third filtering cavity G3, and a capacitor C1 is formed. A window may be disposed between the first filtering cavity G1 and the fourth filtering cavity G4 of the seventh filtering branch 35, and a capacitive flying bar is disposed at the window, so that capacitive cross coupling is achieved between the first filtering cavity G1 and the fourth filtering cavity G4, and a capacitor C2 is formed. A window may be disposed between the fourth filtering cavity G4 and the sixth filtering cavity G6 of the seventh filtering branch 35, and a capacitive flying rod is disposed at the window, so that capacitive cross coupling is achieved between the fourth filtering cavity G4 and the sixth filtering cavity G6, and a capacitor C3 is formed. A window may be disposed between the sixth filtering cavity G6 and the ninth filtering cavity G9 of the seventh filtering branch 35, and a capacitive flying rod is disposed at the window, so that capacitive cross coupling is achieved between the sixth filtering cavity G6 and the ninth filtering cavity G9, and a capacitor C4 is formed. A window may be disposed between the seventh filtering cavity G7 and the ninth filtering cavity G9 of the seventh filtering branch 35, and a capacitive flying bar is disposed at the window, so that capacitive cross coupling is achieved between the seventh filtering cavity G7 and the ninth filtering cavity G9, and a capacitor C5 is formed.

As shown in fig. 11, the first filter cavity H1 and the third filter cavity H3, the first filter cavity H1 and the fourth filter cavity H4 of the eighth filter branch 36 are capacitively cross-coupled, and the sixth filter cavity H6 and the eighth filter cavity H8 are inductively cross-coupled, so as to form three cross-coupled zeros 361 of the eighth filter branch 36, such as capacitors C1, C2, and inductor L1 shown in fig. 11. The setting of the cross-coupling zero 361 of the eighth filtering branch 36 can realize zero suppression, thereby facilitating debugging indexes and meeting design requirements.

Specifically, a window may be disposed between the first filtering cavity H1 and the third filtering cavity H3 of the eighth filtering branch 36, and a capacitive fly rod is disposed at the window, so that capacitive cross coupling is achieved between the first filtering cavity H1 and the third filtering cavity H3, and a capacitor C1 is formed. A window may be disposed between the first filtering cavity H1 and the fourth filtering cavity H4 of the eighth filtering branch 36, and a capacitive flying bar is disposed at the window, so that capacitive cross coupling is achieved between the first filtering cavity H1 and the fourth filtering cavity H4, and a capacitor C2 is formed. A window may be disposed between the sixth filtering cavity H6 and the eighth filtering cavity H8 of the eighth filtering branch 36, and a metal coupling rib is disposed on the window, so that the sixth filtering cavity H6 and the eighth filtering cavity H8 are inductively cross-coupled to form an inductor L1.

As shown in fig. 12, the second filter cavity I2 of the ninth filter branch 37 is capacitively cross-coupled with the fifth filter cavity I5, and the third filter cavity I3 is inductively cross-coupled with the fifth filter cavity I5, so as to form two cross-coupling zeros 371 of the ninth filter branch 37, such as the capacitor C1 and the inductor L1 shown in fig. 12. The setting of the cross-coupling zero 371 of the ninth filtering branch 37 can realize zero suppression, thereby facilitating debugging indexes and meeting design requirements.

Specifically, a window may be disposed between the second filter cavity I2 and the fifth filter cavity I5 of the ninth filter branch 37, and a capacitive fly rod may be disposed at the window, so that capacitive cross coupling is achieved between the second filter cavity I2 and the fifth filter cavity I5, and a capacitor C1 is formed. A window may be disposed between the third filter cavity I3 and the fifth filter cavity I5 of the ninth filter branch 37, and a metal coupling rib is disposed on the window, so that the inductive cross coupling is implemented between the third filter cavity I3 and the fifth filter cavity I5, and an inductor L1 is formed.

Wherein, the ten filter cavities of the tenth filter branch 45, the eight filter cavities of the eleventh filter branch 46, the five filter cavities of the twelfth filter branch 47 and the fourth common cavity 44 are divided into six rows arranged along the second direction D; the fourth filtering cavity J4, the sixth filtering cavity J6, the eighth filtering cavity J8 and the ninth filtering cavity J9 of the tenth filtering branch 45 are in a row and are sequentially arranged along the first direction L; the third filtering cavity J3, the fifth filtering cavity J5, the seventh filtering cavity J7 and the tenth filtering cavity J10 of the tenth filtering branch 45 are in a row and are sequentially arranged along the first direction L; the second filtering cavity J2 of the tenth filtering branch 45, the second filtering cavity K2 of the eleventh filtering branch 46, the first filtering cavity K1 and the fourth common cavity 44 are in a row and are sequentially arranged along the first direction L; the first filtering cavity J1 of the tenth filtering branch 45, the third filtering cavity K3 of the eleventh filtering branch 46, the first filtering cavity L1 of the twelfth filtering branch 47 and the second filtering cavity L2 are in a row and are sequentially arranged along the first direction L; the fifth filtering cavity K5, the fourth filtering cavity K4 of the eleventh filtering branch 46, the fourth filtering cavity L4 and the third filtering cavity L3 of the twelfth filtering branch 47 are in a row and are sequentially arranged along the first direction L; the sixth filter cavity K6, the seventh filter cavity K7, the eighth filter cavity K8 of the eleventh filter branch 46 and the fifth filter cavity L5 of the twelfth filter branch 47 are arranged in a row in sequence along the first direction L.

Further, the fifth filtering cavity J5 of the tenth filtering branch 45 is respectively adjacent to the second filtering cavity J2, the third filtering cavity J3, the fourth filtering cavity J4, the sixth filtering cavity J6, the seventh filtering cavity J7, and the second filtering cavity K2 of the eleventh filtering branch 46; the tenth filtering cavity J10 of the tenth filtering branch 45 is respectively adjacent to the ninth filtering cavity J9, the eighth filtering cavity J8, the seventh filtering cavity J7, the first filtering cavity K1 of the eleventh filtering branch 46 and the fourth common cavity 44; the third filtering cavity K3 of the eleventh filtering branch 46 is respectively adjacent to the fourth filtering cavity K4, the first filtering cavity K1, the second filtering cavity K2, the first filtering cavity J1 of the tenth filtering branch 45, the first filtering cavity L1 of the twelfth filtering branch 47 and the fourth filtering cavity L4; the seventh filtering cavity K7 of the eleventh filtering branch 46 is respectively adjacent to the fourth filtering cavity K4, the fifth filtering cavity J5, the sixth filtering cavity J6 and the eighth filtering cavity J8; the third filter cavity L3 of the twelfth filter branch 47 is respectively adjacent to the first filter cavity L1, the second filter cavity L2, the fourth filter cavity L4 and the fifth filter cavity L5.

The ten filter cavities of the tenth filter branch 45, the eight filter cavities of the eleventh filter branch 46 and the five filter cavities of the twelfth filter branch 47 are regularly arranged, so that the space in the housing 11 can be saved, the size of the filter 10 can be reduced, and the stability of the filter 10 can be improved. Further, the ten filter cavities of the tenth filter branch 45, the eight filter cavities of the eleventh filter branch 46, and the five filter cavities of the twelfth filter branch 47 have the same size, so that the first filter cavity J1 through the tenth filter cavity J10 of the tenth filter branch 45, the first filter cavity K1 through the eighth filter cavity K8 of the eleventh filter branch 46, and the first filter cavity L1 through the fifth filter cavity L5 of the twelfth filter branch 47 in the housing 11 may be distributed and disposed at equal intervals, and the distances between the centers of any two adjacent filter cavities are equal, so that the arrangement is tight, the layout and debugging are facilitated, and the uniformity of the filter 10 is improved.

As shown in fig. 13, the first filtering cavity J1 and the third filtering cavity J3, the first filtering cavity J1 and the fourth filtering cavity J4, the fourth filtering cavity J4 and the sixth filtering cavity J6, the sixth filtering cavity J6 and the eighth filtering cavity J8, and the sixth filtering cavity J6 and the ninth filtering cavity J9 of the tenth filtering branch 45 are respectively cross-coupled in a capacitive manner to form five cross-coupling zeros 451 of the tenth filtering branch 45, which are respectively the capacitors C1, C2, C3, C4, and C5 shown in fig. 13. The setting of the cross-coupling zero 451 of the tenth filtering branch 45 can realize zero suppression, facilitate debugging indexes, and meet design requirements. Moreover, the tenth filtering branch 45 has good consistency of single-capacity materials and high product stability.

Specifically, a window may be disposed between the first filtering cavity J1 and the third filtering cavity J3 of the tenth filtering branch 45, and a capacitive fly rod may be disposed at the window, so that capacitive cross coupling is achieved between the first filtering cavity J1 and the third filtering cavity J3, and a capacitor C1 is formed. A window may be disposed between the first filtering cavity J1 and the fourth filtering cavity J4 of the tenth filtering branch 45, and a capacitive flying bar is disposed at the window, so that capacitive cross coupling is achieved between the first filtering cavity J1 and the fourth filtering cavity J4, and a capacitor C2 is formed. A window may be disposed between the fourth filtering cavity J4 and the sixth filtering cavity J6 of the tenth filtering branch 45, and a capacitive flying rod is disposed at the window, so that capacitive cross coupling is achieved between the fourth filtering cavity J4 and the sixth filtering cavity J6, and a capacitor C3 is formed. A window may be disposed between the sixth filtering cavity J6 and the eighth filtering cavity J8 of the tenth filtering branch 45, and a capacitive flying rod is disposed at the window, so that capacitive cross coupling is achieved between the sixth filtering cavity J6 and the eighth filtering cavity J8, and a capacitor C4 is formed. A window may be disposed between the sixth filtering cavity J6 and the ninth filtering cavity J9 of the tenth filtering branch 45, and a capacitive flying rod may be disposed at the window, so that capacitive cross coupling is achieved between the sixth filtering cavity J6 and the ninth filtering cavity J9, and a capacitor C5 is formed.

As shown in fig. 14, the first filter cavity K1 and the third filter cavity K3 of the eleventh filter branch 46 are inductively cross-coupled, and the fourth filter cavity K4 and the seventh filter cavity K7, and the fifth filter cavity K5 and the seventh filter cavity K7 are capacitively cross-coupled, respectively, to form three cross-coupled zeros 461 of the eleventh filter branch 46, such as an inductor L1, a capacitor C1, and a capacitor C2 shown in fig. 14. The zero suppression can be realized by setting the cross-coupling zero 461 of the eleventh filtering branch 46, so that the debugging index is facilitated, and the design requirement is met.

Specifically, a window may be disposed between the first filter cavity K1 and the third filter cavity K3 of the eleventh filter branch 46, and a metal coupling rib is disposed on the window, so that the inductive cross coupling is implemented between the first filter cavity K1 and the third filter cavity K3, and an inductance L1 is formed. A window may be disposed between the fourth filtering cavity K4 and the seventh filtering cavity K7 of the eleventh filtering branch 46, and a capacitive flying bar is disposed at the window, so that capacitive cross coupling is achieved between the fourth filtering cavity K4 and the seventh filtering cavity K7, and a capacitor C1 is formed. A window may be disposed between the fifth filtering cavity K5 and the seventh filtering cavity K7 of the eleventh filtering branch 46, and a capacitive flying bar is disposed at the window, so that capacitive cross coupling is achieved between the fifth filtering cavity K5 and the seventh filtering cavity K7, and a capacitor C2 is formed.

As shown in fig. 15, the first filter cavity L1 of the twelfth filter branch 47 is inductively cross-coupled to the third filter cavity L3, and the first filter cavity L1 is capacitively cross-coupled to the fourth filter cavity L4, so as to form two cross-coupling zeros 471 of the twelfth filter branch 47, such as the inductor L1 and the capacitor C1 shown in fig. 15. The setting of the cross-coupling zero point 471 of the twelfth filtering branch 47 can realize zero point suppression, thereby facilitating debugging indexes and meeting design requirements.

Specifically, a window may be disposed between the first filter cavity L1 and the third filter cavity L3 of the twelfth filter branch 47, and a metal coupling rib is disposed on the window, so that the inductive cross coupling is implemented between the first filter cavity L1 and the third filter cavity L3, and an inductance L1 is formed. A window may be disposed between the first filter cavity L1 and the fourth filter cavity L4 of the twelfth filter branch 47, and a capacitive fly rod may be disposed at the window, so that capacitive cross coupling is achieved between the first filter cavity L1 and the fourth filter cavity L4, and a capacitor C1 is formed.

Optionally, a ninth port (not shown), a tenth port (not shown), an eleventh port (not shown) and a twelfth port (not shown) are further disposed on the housing 11.

The tenth filtering cavity a10 of the first filtering branch 15 is connected to the ninth port, the tenth filtering cavity D10 of the fourth filtering branch 25 is connected to the tenth port, the tenth filtering cavity G10 of the seventh filtering branch 35 is connected to the eleventh port, and the tenth filtering cavity J10 of the tenth filtering branch 45 is connected to the twelfth port.

The first port 12 to the twelfth port may be taps of the filter 10.

The bandwidth of the first filtering branch 15 of the present embodiment is in the range of 2511Mhz-2676 Mhz. In particular, the coupling bandwidth between the first port 12 and the first filter cavity a1 of the first filter branch 15 ranges from 163Mhz to 186 Mhz; the coupling bandwidth between the first filter cavity a1 and the second filter cavity a2 of the first filter branch 15 ranges from 127Mhz to 146 Mhz; the coupling bandwidth between the second filter cavity a2 and the third filter cavity A3 of the first filter branch 15 ranges from 86Mhz to 100 Mhz; the coupling bandwidth between the second filter cavity a2 and the fifth filter cavity a5 of the first filter branch 15 ranges from 10Mhz to 16 Mhz; the coupling bandwidth between the third filter cavity A3 and the fourth filter cavity a4 of the first filter branch 15 ranges from 48Mhz to 58 Mhz; the coupling bandwidth between the third filter cavity A3 and the fifth filter cavity a5 of the first filter branch 15 ranges from-63 Mhz to-52 Mhz; the coupling bandwidth between the fourth filter cavity a4 and the fifth filter cavity a5 of the first filter branch 15 ranges from 53Mhz to 64 Mhz; the coupling bandwidth between the fifth filter cavity a5 and the sixth filter cavity a6 of the first filter branch 15 ranges from 75Mhz to 88 Mhz; the coupling bandwidth between the fifth filter cavity a5 and the eighth filter cavity A8 of the first filter branch 15 ranges from-15 Mhz to-9 Mhz; the coupling bandwidth between the sixth filter cavity a6 and the seventh filter cavity a7 of the first filter branch 15 ranges from 88Mhz to 103 Mhz; the coupling bandwidth between the sixth filter cavity a6 and the eighth filter cavity A8 of the first filter branch 15 ranges from 2Mhz to 7 Mhz; the coupling bandwidth between the seventh filter cavity a7 and the eighth filter cavity A8 of the first filter branch 15 ranges from 78Mhz to 91 Mhz; the coupling bandwidth between the eighth filter cavity A8 and the ninth filter cavity a9 of the first filter branch 15 ranges from 77Mhz to 90 Mhz; the coupling bandwidth between the eighth filter cavity A8 and the tenth filter cavity a10 of the first filter branch 15 ranges from 47Mhz to 57 Mhz; the coupling bandwidth between the ninth filter cavity a9 and the tenth filter cavity a10 of the first filter branch 15 ranges from 117Mhz to 135 Mhz; the coupling bandwidth between the tenth filter cavity a10 and the ninth port of the first filter branch 15 ranges from 163Mhz to 186 Mhz.

The bandwidth of the second filtering branch 16 of this embodiment lies in the range 1884Mhz-1916 Mhz. Specifically, the coupling bandwidth between the first port 12 and the first common cavity 14 ranges from 258Mhz to 291 Mhz; the coupling bandwidth between the first common cavity 14 and the first filter cavity B1 of the second filter branch 16 ranges from 82Mhz to 96 Mhz; the coupling bandwidth between the first filter cavity B1 and the second filter cavity B2 of the second filter branch 16 ranges from 21Mhz to 28 Mhz; the coupling bandwidth between the second filter cavity B2 and the third filter cavity B3 of the second filter branch 16 ranges from 16Mhz to 22 Mhz; the coupling bandwidth between the third filter cavity B3 and the fourth filter cavity B4 of the second filter branch 16 ranges from 14Mhz to 20 Mhz; the coupling bandwidth between the third filter cavity B3 and the sixth filter cavity B6 of the second filter branch 16 ranges from-8 Mhz to-3 Mhz; the coupling bandwidth between the fourth filter cavity B4 and the fifth filter cavity B5 of the second filter branch 16 ranges from 18Mhz to 25 Mhz; the coupling bandwidth between the fourth filter cavity B4 and the sixth filter cavity B6 of the second filter branch 16 ranges from-4 Mhz-1 Mhz; the coupling bandwidth between the fifth filter cavity B5 and the sixth filter cavity B6 of the second filter branch 16 ranges from 13Mhz to 19 Mhz; the coupling bandwidth between the sixth filter cavity B6 and the seventh filter cavity B7 of the second filter branch 16 ranges from 8Mhz to 14 Mhz; the coupling bandwidth between the sixth filter cavity B6 and the eighth filter cavity B8 of the second filter branch 16 ranges from 16Mhz to 22 Mhz; the coupling bandwidth between the seventh filter cavity B7 and the eighth filter cavity B8 of the second filter branch 16 ranges from 16Mhz to 22 Mhz; the coupling bandwidth between the eighth filter cavity B8 of the second filter branch 16 and the second port 13 ranges from 29Mhz to 37 Mhz.

The bandwidth of the third filtering branch 17 of the present embodiment is in the range of 2009Mhz-2026 Mhz. In particular, the coupling bandwidth between the first common cavity 14 and the first filtering cavity C1 of the third filtering branch 17 ranges from 82Mhz to 96 Mhz; the coupling bandwidth between the first filter cavity C1 and the second filter cavity C2 of the third filter branch 17 ranges from 18Mhz to 25 Mhz; the coupling bandwidth between the first filter cavity C1 and the fourth filter cavity C4 of the third filter branch 17 ranges from-3 Mhz to 2 Mhz; the coupling bandwidth between the second filter cavity C2 and the third filter cavity C3 of the third filter branch 17 ranges from 14Mhz to 20 Mhz; the coupling bandwidth between the second filter cavity C2 and the fourth filter cavity C4 of the third filter branch 17 ranges from-2 Mhz to 2 Mhz; the coupling bandwidth between the third filter cavity C3 and the fourth filter cavity C4 of the third filter branch 17 ranges from 13Mhz to 19 Mhz; the coupling bandwidth between the fourth filter cavity C4 and the fifth filter cavity C5 of the third filter branch 17 ranges from 20Mhz to 27 Mhz; the coupling bandwidth between the fifth filter cavity C5 of the third filter branch 17 and the second port 13 is in the range of 26Mhz-34 Mhz.

The bandwidth of the fourth filtering branch 25 of the present embodiment is in the range of 2511Mhz-2676 Mhz. In particular, the coupling bandwidth between the third port 22 and the first filter cavity D1 of the fourth filter branch 25 ranges from 163Mhz to 186 Mhz; the coupling bandwidth between the first filter cavity D1 and the second filter cavity D2 of the fourth filter branch 25 ranges from 125Mhz to 144 Mhz; the coupling bandwidth between the first filter cavity D1 and the fourth filter cavity D4 of the fourth filter branch 25 ranges from 18Mhz to 25 Mhz; the coupling bandwidth between the second filter cavity D2 and the third filter cavity D3 of the fourth filter branch 25 ranges from 52Mhz to 62 Mhz; the coupling bandwidth between the second filter cavity D2 and the fourth filter cavity D4 of the fourth filter branch 25 ranges from-69 Mhz to-58 Mhz; the coupling bandwidth between the third filter cavity D3 and the fourth filter cavity D4 of the fourth filter branch 25 ranges from 54Mhz to 65 Mhz; the coupling bandwidth between the fourth filter cavity D4 and the fifth filter cavity D5 of the fourth filter branch 25 ranges from 72Mhz to 85 Mhz; the coupling bandwidth between the fourth filter cavity D4 and the sixth filter cavity D6 of the fourth filter branch 25 ranges from-34 Mhz to-26 Mhz; the coupling bandwidth between the fifth filter cavity D5 and the sixth filter cavity D6 of the fourth filter branch 25 ranges from 72Mhz to 85 Mhz; the coupling bandwidth between the sixth filter cavity D6 and the seventh filter cavity D7 of the fourth filter branch 25 ranges from 56Mhz to 67 Mhz; the coupling bandwidth between the sixth filter cavity D6 and the eighth filter cavity D8 of the fourth filter branch 25 ranges from 51Mhz to 61 Mhz; the coupling bandwidth between the sixth filter cavity D6 and the ninth filter cavity D9 of the fourth filter branch 25 ranges from 10Mhz to 16 Mhz; the coupling bandwidth between the seventh filter cavity D7 and the eighth filter cavity D8 of the fourth filter branch 25 ranges from 50Mhz to 60 Mhz; the coupling bandwidth between the eighth filter cavity D8 and the ninth filter cavity D9 of the fourth filter branch 25 ranges from 86Mhz to 100 Mhz; the coupling bandwidth between the ninth filter cavity D9 and the tenth filter cavity D10 of the fourth filter branch 25 ranges from 127Mhz to 146 Mhz; the coupling bandwidth between the tenth filter cavity D10 and the tenth port of the fourth filter branch 25 ranges from 163Mhz to 186 Mhz.

The bandwidth of the fifth filtering branch 26 of this embodiment lies in the range 1884Mhz-1916 Mhz. Specifically, the coupling bandwidth between the third port 22 and the second common cavity 24 ranges from 258Mhz to 291 Mhz; the coupling bandwidth between the second common cavity 24 and the first filter cavity E1 of the fifth filter branch 26 ranges from 82Mhz to 96 Mhz; the coupling bandwidth between the first filter cavity E1 and the second filter cavity E2 of the fifth filter branch 26 ranges from 21Mhz to 28 Mhz; the coupling bandwidth between the second filter cavity E2 and the third filter cavity E3 of the fifth filter branch 26 ranges from 13Mhz to 19 Mhz; the coupling bandwidth between the second filter cavity E2 and the fourth filter cavity E4 of the fifth filter branch 26 ranges from 7Mhz to 13 Mhz; the coupling bandwidth between the third filter cavity E3 and the fourth filter cavity E4 of the fifth filter branch 26 ranges from 11Mhz to 17 Mhz; the coupling bandwidth between the fourth filter cavity E4 and the fifth filter cavity E5 of the fifth filter branch 26 ranges from 12Mhz to 18 Mhz; the coupling bandwidth between the fourth filter cavity E4 and the seventh filter cavity E7 of the fifth filter branch 26 ranges from-9 Mhz to-4 Mhz; the coupling bandwidth between the fifth filter cavity E5 and the sixth filter cavity E6 of the fifth filter branch 26 ranges from 20Mhz to 27 Mhz; the coupling bandwidth between the fifth filter cavity E5 and the seventh filter cavity E7 of the fifth filter branch 26 ranges from-2 Mhz-3 Mhz; the coupling bandwidth between the sixth filter cavity E6 and the seventh filter cavity E7 of the fifth filter branch 26 ranges from 14Mhz to 20 Mhz; the coupling bandwidth between the seventh filter cavity E7 and the eighth filter cavity E8 of the fifth filter branch 26 ranges from 23Mhz to 30 Mhz; the coupling bandwidth between the eighth filter cavity E8 of the fifth filter branch 26 and the fourth port 23 ranges from 29Mhz to 37 Mhz.

The bandwidth of the sixth filtering branch 27 of the present embodiment is in the range of 2009Mhz-2026 Mhz. In particular, the coupling bandwidth between the second common cavity 24 and the first filter cavity F1 of the sixth filter branch 27 ranges from 82Mhz to 96 Mhz; the coupling bandwidth between the first filter cavity F1 and the second filter cavity F2 of the sixth filter branch 27 ranges from 18Mhz to 25 Mhz; the coupling bandwidth between the first filter cavity F1 and the third filter cavity F3 of the sixth filter branch 27 ranges from-2 Mhz to 2 Mhz; the coupling bandwidth between the first filter cavity F1 and the fourth filter cavity F4 of the sixth filter branch 27 ranges from-3 Mhz to 2 Mhz; the coupling bandwidth between the second filter cavity F2 and the third filter cavity F3 of the sixth filter branch 27 ranges from 14Mhz to 20 Mhz; the coupling bandwidth between the third filter cavity F3 and the fourth filter cavity F4 of the sixth filter branch 27 ranges from 13Mhz to 19 Mhz; the coupling bandwidth between the fourth filter cavity F4 and the fifth filter cavity F5 of the sixth filter branch 27 ranges from 20Mhz to 27 Mhz; the coupling bandwidth between the fifth filter cavity F5 and the fourth port 23 of the sixth filter branch 27 is in the range of 26Mhz-34 Mhz.

The bandwidth of the seventh filtering branch 35 of the present embodiment is in the range of 2511Mhz-2676 Mhz. In particular, the coupling bandwidth between the fifth port 32 and the first filtering cavity G1 of the seventh filtering branch 35 ranges from 163Mhz to 186 Mhz; the coupling bandwidth between the first filter cavity G1 and the second filter cavity G2 of the seventh filter branch 35 ranges from 85Mhz to 99 Mhz; the coupling bandwidth between the first filter cavity G1 and the third filter cavity G3 of the seventh filter branch 35 ranges from-105 Mhz to 90 Mhz; the coupling bandwidth between the first filter cavity G1 and the fourth filter cavity G4 of the seventh filter branch 35 ranges from 18Mhz to 25 Mhz; the coupling bandwidth between the second filter cavity G2 and the third filter cavity G3 of the seventh filter branch 35 ranges from 40Mhz to 49 Mhz; the coupling bandwidth between the third filter cavity G3 and the fourth filter cavity G4 of the seventh filter branch 35 ranges from 80Mhz to 94 Mhz; the coupling bandwidth between the fourth filter cavity G4 and the fifth filter cavity G5 of the seventh filter branch 35 ranges from 72Mhz to 85 Mhz; the coupling bandwidth between the fourth filter cavity G4 and the sixth filter cavity G6 of the seventh filter branch 35 ranges from-34 Mhz to-26 Mhz; the coupling bandwidth between the fifth filter cavity G5 and the sixth filter cavity G6 of the seventh filter branch 35 ranges from 72Mhz to 85 Mhz; the coupling bandwidth between the sixth filter cavity G6 and the seventh filter cavity G7 of the seventh filter branch 35 ranges from 77Mhz to 90 Mhz; the coupling bandwidth between the sixth filter cavity G6 and the ninth filter cavity G9 of the seventh filter branch 35 ranges from 10Mhz to 16 Mhz; the coupling bandwidth between the seventh filtering cavity G7 and the eighth filtering cavity G8 of the seventh filtering branch 35 ranges from 46Mhz to 56 Mhz; the coupling bandwidth between the seventh filter cavity G7 and the ninth filter cavity G9 of the seventh filter branch 35 ranges from 57Mhz to 68 Mhz; the coupling bandwidth between the eighth filter cavity G8 and the ninth filter cavity G9 of the seventh filter branch 35 ranges from 62Mhz to 74 Mhz; the coupling bandwidth between the ninth filter cavity G9 and the tenth filter cavity G10 of the seventh filter branch 35 ranges from 127Mhz to 146 Mhz; the coupling bandwidth between the tenth filtering cavity G10 of the seventh filtering branch 35 and the eleventh port ranges from 163Mhz to 186 Mhz.

The bandwidth of the eighth filtering branch 36 of this embodiment lies in the range 1884Mhz-1916 Mhz. Specifically, the coupling bandwidth between the fifth port 32 and the third common cavity 34 ranges from 258Mhz to 291 Mhz; the coupling bandwidth between the third common cavity 34 and the first filter cavity H1 of the eighth filter branch 36 ranges from 82Mhz to 96 Mhz; the coupling bandwidth between the first filter cavity H1 and the second filter cavity H2 of the eighth filter branch 36 is in the range of 19Mhz-26 Mhz; the coupling bandwidth between the first filter cavity H1 and the third filter cavity H3 of the eighth filter branch 36 ranges from-3 Mhz to 2 Mhz; the coupling bandwidth between the first filter cavity H1 and the fourth filter cavity H4 of the eighth filter branch 36 ranges from-11 Mhz-4 Mhz; the coupling bandwidth between the second filter cavity H2 and the third filter cavity H3 of the eighth filter branch 36 ranges from 22Mhz to 29 Mhz; the coupling bandwidth between the third filter cavity H3 and the fourth filter cavity H4 of the eighth filter branch 36 ranges from 12Mhz to 18 Mhz; the coupling bandwidth between the fourth filter cavity H4 and the fifth filter cavity H5 of the eighth filter branch 36 ranges from 14Mhz to 20 Mhz; the coupling bandwidth between the fifth filter cavity H5 and the sixth filter cavity H6 of the eighth filter branch 36 ranges from 14Mhz to 20 Mhz; the coupling bandwidth between the sixth filter cavity H6 and the seventh filter cavity H7 of the eighth filter branch 36 ranges from 8Mhz to 14 Mhz; the coupling bandwidth between the sixth filter cavity H6 and the eighth filter cavity H8 of the eighth filter branch 36 ranges from 16Mhz to 22 Mhz; the coupling bandwidth between the seventh filter cavity H7 and the eighth filter cavity H8 of the eighth filter branch 36 ranges from 16Mhz to 22 Mhz; the coupling bandwidth between the eighth filter cavity H8 of the eighth filter branch 36 and the sixth port 33 ranges from 29Mhz to 37 Mhz.

The bandwidth of the ninth filtering branch 37 of the present embodiment is in the range of 2009Mhz-2026 Mhz. In particular, the coupling bandwidth between the third common cavity 44 and the first filter cavity I1 of the ninth filter branch 37 ranges from 82Mhz to 96 Mhz; the coupling bandwidth between the first filter cavity I1 and the second filter cavity I2 of the ninth filter branch 37 ranges from 18Mhz to 25 Mhz; the coupling bandwidth between the second filter cavity I2 and the third filter cavity I3 of the ninth filter branch 37 ranges from 13Mhz to 17 Mhz; the coupling bandwidth between the second filter cavity I2 and the fifth filter cavity I5 of the ninth filter branch 37 ranges from-3 Mhz to 2 Mhz; the coupling bandwidth between the third filter cavity I3 and the fourth filter cavity I4 of the ninth filter branch 37 ranges from 14Mhz to 20 Mhz; the coupling bandwidth between the third filter cavity I3 and the fifth filter cavity I5 of the ninth filter branch 37 ranges from-2 Mhz to 2 Mhz; the coupling bandwidth between the fourth filter cavity I4 and the fifth filter cavity I5 of the ninth filter branch 37 ranges from 20Mhz to 27 Mhz; the coupling bandwidth between the fifth filter cavity I5 and the sixth port 33 of the ninth filter branch 37 is in the range of 26Mhz-34 Mhz.

The bandwidth of the tenth filtering branch 45 of the present embodiment is in the range of 2511Mhz-2676 Mhz. In particular, the coupling bandwidth between the seventh port 42 and the first filter cavity J1 of the tenth filter branch 45 ranges from 163Mhz to 186 Mhz; the coupling bandwidth between the first filtering cavity J1 and the second filtering cavity J2 of the tenth filtering branch 45 ranges from 85Mhz to 99 Mhz; the coupling bandwidth between the first filter cavity J1 and the third filter cavity J3 of the tenth filter branch 45 ranges from-105 Mhz to 90 Mhz; the coupling bandwidth between the first filtering cavity J1 and the fourth filtering cavity J4 of the tenth filtering branch 45 ranges from 18Mhz to 25 Mhz; the coupling bandwidth between the second filter cavity J2 and the third filter cavity J3 of the tenth filter branch 45 ranges from 40Mhz to 49 Mhz; the coupling bandwidth between the third filter cavity J3 and the fourth filter cavity J4 of the tenth filter branch 45 ranges from 80Mhz to 94 Mhz; the coupling bandwidth between the fourth filter cavity J4 and the fifth filter cavity J5 of the tenth filter branch 45 ranges from 72Mhz to 85 Mhz; the coupling bandwidth between the fourth filter cavity J4 and the sixth filter cavity J6 of the tenth filter branch 45 ranges from-34 Mhz to-26 Mhz; the coupling bandwidth between the fifth filter cavity J5 and the sixth filter cavity J6 of the tenth filter branch 45 ranges from 72Mhz to 85 Mhz; the coupling bandwidth between the sixth filtering cavity J6 and the seventh filtering cavity J7 of the tenth filtering branch 45 ranges from 56Mhz to 67 Mhz; the coupling bandwidth between the sixth filtering cavity J6 and the eighth filtering cavity J8 of the tenth filtering branch 45 ranges from 51Mhz to 61 Mhz; the coupling bandwidth between the sixth filter cavity J6 and the ninth filter cavity J9 of the tenth filter branch 45 ranges from 10Mhz to 14 Mhz; the coupling bandwidth between the seventh filtering cavity J7 and the eighth filtering cavity J8 of the tenth filtering branch 45 ranges from 50Mhz to 60 Mhz; the coupling bandwidth between the eighth filter cavity J8 and the ninth filter cavity J9 of the tenth filter branch 45 ranges from 86Mhz to 100 Mhz; the coupling bandwidth between the ninth filtering cavity J9 and the tenth filtering cavity J10 of the tenth filtering branch 45 ranges from 127Mhz to 146 Mhz; the coupling bandwidth between the tenth filtering cavity J10 of the tenth filtering branch 45 and the twelfth port ranges from 163Mhz to 186 Mhz.

The bandwidth of the eleventh filtering branch 46 of this embodiment lies in the range 1884Mhz-1916 Mhz. Specifically, the coupling bandwidth between the seventh port 42 and the fourth common cavity 44 ranges from 258Mhz to 291 Mhz; the coupling bandwidth between the fourth common cavity 44 and the first filter cavity K1 of the eleventh filter branch 46 ranges from 82Mhz to 96 Mhz; the coupling bandwidth between the first filter cavity K1 and the second filter cavity K2 of the eleventh filter branch 46 ranges from 16Mhz to 23 Mhz; the coupling bandwidth between the first filter cavity K1 and the third filter cavity K3 of the eleventh filter branch 46 is in the range of 11Mhz-17 Mhz; the coupling bandwidth between the second filter cavity K2 and the third filter cavity K3 of the eleventh filter branch 46 ranges from 10Mhz to 16 Mhz; the coupling bandwidth between the third filter cavity K3 and the fourth filter cavity K4 of the eleventh filter branch 46 ranges from 14Mhz to 20 Mhz; the coupling bandwidth between the fourth filter cavity K4 and the fifth filter cavity K5 of the eleventh filter branch 46 ranges from 14Mhz to 20 Mhz; the coupling bandwidth between the fifth filter cavity K5 and the sixth filter cavity K6 of the eleventh filter branch 46 ranges from 11Mhz to 17 Mhz; the coupling bandwidth between the fifth filter cavity K5 and the eighth filter cavity K8 of the eleventh filter branch 46 ranges from-14 Mhz to-8 Mhz; the coupling bandwidth between the sixth filter cavity K6 and the seventh filter cavity K7 of the eleventh filter branch 46 ranges from 22Mhz to 29 Mhz; the coupling bandwidth between the sixth filter cavity K6 and the eighth filter cavity K8 of the eleventh filter branch 46 ranges from 0Mhz to 5 Mhz; the coupling bandwidth between the seventh filter cavity K7 and the eighth filter cavity K8 of the eleventh filter branch 46 ranges from 20Mhz to 27 Mhz; the coupling bandwidth between the eighth filter cavity K8 of the eleventh filter branch 46 and the eighth port 43 ranges from 29Mhz to 37 Mhz.

The bandwidth of the twelfth filtering branch 47 of the present embodiment is in the range of 2009Mhz-2026 Mhz. In particular, the coupling bandwidth between the fourth common cavity 44 and the first filter cavity L1 of the twelfth filter branch 47 ranges from 82Mhz to 96 Mhz; the coupling bandwidth between the first filter cavity L1 and the second filter cavity L2 of the twelfth filter branch 47 ranges from 18Mhz to 25 Mhz; the coupling bandwidth between the first filter cavity L1 and the third filter cavity L3 of the twelfth filter branch 47 ranges from-2 Mhz to 2 Mhz; the coupling bandwidth between the first filter cavity L1 and the fourth filter cavity L4 of the twelfth filter branch 47 ranges from-3 Mhz to 2 Mhz; the coupling bandwidth between the second filter cavity L2 and the third filter cavity L3 of the twelfth filter branch 47 ranges from 14Mhz to 20 Mhz; the coupling bandwidth between the third filter cavity L3 and the fourth filter cavity L4 of the twelfth filter branch 47 ranges from 13Mhz to 19 Mhz; the coupling bandwidth between the fourth filter cavity L4 and the fifth filter cavity L5 of the twelfth filter branch 47 ranges from 20Mhz to 27 Mhz; the coupling bandwidth between the fifth filter cavity L5 and the eighth port 43 of the twelfth filter branch 47 is in the range of 26Mhz-34 Mhz.

Therefore, the resonant frequencies of the first filter cavity a1 through the tenth filter cavity a10 of the first filter branch 15 are sequentially located in the following ranges: 2592Mhz-2594Mhz, 2583Mhz-2585Mhz, 2533Mhz-2535Mhz, 2593Mhz-2595Mhz, 2591Mhz-2593Mhz, 2596Mhz-2598Mhz, 2586Mhz-2588Mhz, 2630Mhz-2632Mhz and 2592Mhz-2594 Mhz.

The resonant frequency of the first common cavity 14 is in the range 1955Mhz-1957 Mhz.

The resonant frequencies of the first filter cavity B1 through the eighth filter cavity B8 of the second filter branch 16 are sequentially in the following ranges: 1901Mhz-1903Mhz, 1899Mhz-1901Mhz, 1900Mhz-1902Mhz, 1896Mhz-1898Mhz, 1897Mhz-1899Mhz, 1912Mhz-1914Mhz, and 1899Mhz-1901 Mhz.

The resonant frequencies of the first filter cavity C1 to the fifth filter cavity C5 of the third filter branch 17 are sequentially in the following ranges: 2012Mhz-2014Mhz, 2016Mhz-2018Mhz, 2017Mhz-2019 Mhz.

The resonant frequencies of the first filter cavity D1 through the tenth filter cavity D10 of the fourth filter branch 25 are sequentially in the following ranges: 2592Mhz-2594Mhz, 2581Mhz-2584Mhz, 2530Mhz-2532Mhz, 2596Mhz-2598Mhz, 2562Mhz-2564Mhz, 2591Mhz-2593Mhz, 2651Mhz2653Mhz, 2601Mhz-2603Mhz, 2592Mhz-2594 Mhz.

The resonant frequency of the second common cavity 24 is in the range 1955Mhz-1957 Mhz.

The resonant frequencies of the first filter cavity E1 through the eighth filter cavity E8 of the fifth filter branch 26 are in the following ranges in sequence: 1901Mhz-1903Mhz, 1899Mhz-1901Mhz, 1900Mhz-1902Mhz, 1896Mhz-1898Mhz, 1897Mhz-1899Mhz, 1912Mhz-1914Mhz, and 1899Mhz-1901 Mhz.

The resonant frequencies of the first filter cavity F1 through the fifth filter cavity F5 of the sixth filter branch 27 are sequentially in the following ranges: 2012Mhz-2014Mhz, 2016Mhz-2018Mhz, 2017Mhz-2019 Mhz.

The resonant frequencies of the first filtering cavity G1 through the tenth filtering cavity G10 of the seventh filtering branch 35 are sequentially in the following ranges: 2592Mhz-2594Mhz, 2524Mhz-2526Mhz, 2587Mhz-2589Mhz, 2596Mhz-2598Mhz, 2562Mhz-2564Mhz, 2591Mhz-2593Mhz, 2599Mhz-2601Mhz, 2653Mhz-2655Mhz, 2592Mhz-2594 Mhz.

The resonant frequency of the third common cavity 34 is in the range 1955Mhz-1957 Mhz.

The resonant frequencies of the first filter cavity H1 through the eighth filter cavity H8 of the eighth filter branch 36 are sequentially in the following ranges: 1901Mhz-1903Mhz, 1898Mhz-1900Mhz, 1899Mhz-1901Mhz, 1898Mhz-1900Mhz, 1897Mhz-1899Mhz, 1912Mhz-1914Mhz, and 1899Mhz-1901 Mhz.

The resonant frequencies of the first filter cavity I1 through the fifth filter cavity I5 of the ninth filter branch 37 are sequentially in the following ranges: 2012Mhz-2014Mhz, 2016Mhz-2018Mhz, 2017Mhz-2019 Mhz.

The resonant frequencies of the first filtering cavity J1 through the tenth filtering cavity J10 of the tenth filtering branch 45 are sequentially located in the following ranges: 2592Mhz-2594Mhz, 2524Mhz-2526Mhz, 2587Mhz-2589Mhz, 2596Mhz-2598Mhz, 2562Mhz-2564Mhz, 2591Mhz-2593Mhz, 2651Mhz-2653Mhz, 2601Mhz-2603Mhz, 2592Mhz-2594 Mhz.

The resonant frequency of the fourth common cavity 44 is in the range 1955Mhz-1957 Mhz.

The resonant frequencies of the first filter cavity K1 through the eighth filter cavity K8 of the eleventh filter branch 46 are sequentially in the following ranges: 1901Mhz-1903Mhz, 1911Mhz-1913Mhz, 1897Mhz-1900Mhz, 1898Mhz-1900Mhz, 1897Mhz-1899Mhz, 1901Mhz-1903Mhz, and 1899Mhz-1901 Mhz.

The resonant frequencies of the first filter cavity L1 through the fifth filter cavity L5 of the twelfth filter branch 47 are sequentially in the following ranges: 2012Mhz-2014Mhz, 2017Mhz-2019 Mhz.

It can be seen that the resonant frequencies of the filter cavities of the first filter branch 15, the fourth filter branch 25 and the seventh filter branch 35 are substantially the same; the resonant frequencies of the filter cavities of the second filter branch 16, the fifth filter branch 26 and the eighth filter branch 36 are substantially the same, wherein the resonant frequencies of the filter cavities of the second filter branch 16 and the fifth filter branch 26 are substantially the same; the resonant frequencies of the filter cavities of the third filter branch 17, the sixth filter branch 27 and the ninth filter branch 37 are substantially the same; the convenience of manufacturing and debugging the filter 10 is improved, namely the filter can be manufactured by adopting the same specification parameters in the manufacturing process, and the required parameter range can be reached only by simple debugging in the actual process.

As shown in fig. 16, fig. 16 is a schematic diagram of a first simulation result of the filter provided in the present application. Through experimental tests, the bandwidths of the first filtering branch 15, the fourth filtering branch 25, the seventh filtering branch 35 and the tenth filtering branch 45 of the present application are within a range of 2511Mhz-2676Mhz, as shown by a frequency band curve 21 in fig. 16. The bandwidth rejection of the band curve 21 is greater than 85dB at a frequency of 2445Mhz, greater than 65dB at a frequency of 2483.5Mhz, greater than 45dB at a frequency of 2500Mhz, greater than 45dB at a frequency of 2700Mhz, and greater than 65dB at a frequency of 2745 Mhz. Therefore, the performance of the filter 10 such as out-of-band rejection can be improved.

Further, as shown in the frequency band curve 21 in fig. 16, one inductive cross-coupling zero 151 of the first filtering branch 15 is zero a, and the frequency of the zero a is 2700Mhz, where the bandwidth rejection is greater than 66 dB.

As shown in fig. 17, fig. 17 is a schematic diagram of a second simulation result of the filter provided in the present application. Through experimental tests, the bandwidths of the second filtering branch 16, the fifth filtering branch 26, the eighth filtering branch 36 and the eleventh filtering branch 46 of the present application are in the range of 1884Mhz-1916Mhz, as shown by the frequency band curve 22 in fig. 17, and the bandwidths of the third filtering branch 17, the sixth filtering branch 27, the ninth filtering branch 37 and the twelfth filtering branch 47 are in the range of 2009Mhz-2026Mhz, as shown by the frequency band curve 23 in fig. 17. The band rejection of the band curves 22 and 23 is greater than 90dB at 1778Mhz, greater than 86dB at 1785Mhz, greater than 60dB at 1850Mhz, greater than 38dB at 1870Mhz, greater than 32dB at 1875Mhz, greater than 28dB at 1880Mhz, greater than 42dB at 1920Mhz, greater than 57dB at 1945Mhz, greater than 57dB at 1960Mhz, greater than 50dB at 1980Mhz, greater than 25dB at 1990Mhz, and greater than 47dB at 2055 Mhz. Therefore, the performance of the filter 10 such as out-of-band rejection can be improved.

Further, as shown in the frequency band curve 22 in fig. 17, one cross-coupling zero 161 of the second filtering branch 16 is zero B, which has a frequency of 1880Mhz, and the bandwidth rejection is greater than 39 dB. As shown in the frequency band curve 23 in fig. 17, one cross-coupling zero 171 of the third filtering branch 17 is zero C, whose frequency is 1978Mhz, and where the bandwidth rejection is greater than 78 dB.

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.

Therefore, the filter 10 of the present application can reduce the size of the filter 10 and improve the performance of the filter 10 such as out-of-band rejection.

The present application further provides a communication system, as shown in fig. 18, fig. 18 is a schematic structural diagram of an embodiment of the communication system of the present application. The communication system 50 of the present embodiment includes an antenna 51 and a radio frequency unit 52 connected to the antenna 51, wherein the radio frequency unit 52 includes the filter 10 as shown in the above-mentioned embodiment, and the filter 10 is used for filtering the radio frequency signal. In other embodiments, the rf Unit 52 may be integrally designed with the Antenna 51 to form an Active Antenna Unit (AAU).

Some embodiments of the present application are referred to as filters, and it is understood that in other embodiments, the present application may also be a combiner, i.e., a dual-frequency combiner.

The principle and the implementation of the present application are explained herein by applying specific examples, and the above description of the embodiments is only used to help understand the method and the core idea of the present application; meanwhile, for a person skilled in the art, according to the idea of the present application, there may be variations in the specific embodiments and the application scope, and in summary, the content of the present specification should not be construed as a limitation to the present application.

Claims

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

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

2. The filter of claim 1,

ten filter cavities of the first filter branch, eight filter cavities of the second filter branch, five filter cavities of the third filter branch and the first common cavity are divided into six rows arranged along the first direction;

the second filtering cavity, the first filtering cavity, the ninth filtering cavity and the tenth filtering cavity of the first filtering branch are in a row and are sequentially arranged along the second direction;

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

the fourth filtering cavity, the fifth filtering cavity, the seventh 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 are in a row and are sequentially arranged along the second direction;

the fourth filtering cavity, the third filtering cavity and the second filtering cavity of the second filtering branch circuit are in a row and are sequentially arranged along the second direction;

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

the third filtering cavity of the first filtering branch is respectively adjacent to the first filtering cavity, the second filtering cavity, the fourth filtering cavity, the fifth filtering cavity and the sixth filtering cavity;

the eighth filtering cavity of the first filtering branch is respectively adjacent to the sixth filtering cavity, the seventh filtering cavity, the ninth filtering cavity, the tenth filtering cavity, the first common cavity and the first filtering cavity of the second filtering branch;

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

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

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

and the eighth filtering cavity of the second filtering branch is respectively adjacent to the sixth filtering cavity and the seventh filtering cavity.

3. The filter of claim 2,

inductive cross coupling is respectively carried out between a fifth filtering cavity and an eighth filtering cavity of the first filtering branch and between the eighth filtering cavity and a tenth filtering cavity of the first filtering branch, capacitive cross coupling is respectively carried out between the second filtering cavity and the fifth filtering cavity, between the third filtering cavity and the fifth filtering cavity and between the sixth filtering cavity and the eighth filtering cavity, so as to form five cross coupling zeros of the first filtering branch;

capacitive cross coupling is respectively performed between a third filtering cavity and a sixth filtering cavity of the second filtering branch, between a fourth filtering cavity and the sixth filtering cavity, and inductive cross coupling is performed between the sixth filtering cavity and an eighth filtering cavity to form three cross coupling zeros of the second filtering branch;

and the first filtering cavity and the fourth filtering cavity of the third filtering branch circuit are in capacitive cross coupling, and the second filtering cavity and the fourth filtering cavity are in inductive cross coupling, so that two cross coupling zeros of the third filtering branch circuit are formed.

4. The filter of claim 3, further comprising:

a third port, a fourth port and a second common chamber connected to the third port, disposed on the housing;

the fourth filtering branch is coupled with the third port and consists of ten filtering cavities which are sequentially coupled, and five cross-coupling zero points are further formed by the ten filtering cavities of the fourth filtering branch;

the fifth filtering branch is respectively coupled with the second common cavity and the fourth port and consists of eight filtering cavities which are sequentially coupled, and the eight filtering cavities of the fifth filtering branch further form three cross-coupling zeros;

and the sixth filtering branch circuit is coupled with the second common cavity and the fourth port respectively and consists of five filtering cavities which are sequentially coupled, and the five filtering cavities of the sixth filtering branch circuit further form two cross-coupling zero points.

5. The filter of claim 4,

ten filter cavities of the fourth filter branch, eight filter cavities of the fifth filter branch, five filter cavities of the sixth filter branch and the second common cavity are divided into six rows arranged along the second direction;

the sixth filtering cavity, the seventh filtering cavity and the eighth filtering cavity of the fifth filtering branch are in a row and are sequentially arranged along the first direction;

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

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

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

the third filtering cavity, the fifth filtering cavity, the seventh filtering cavity and the tenth filtering cavity of the fourth filtering branch are in a row and are sequentially arranged along the first direction;

the fourth filtering cavity, the eighth filtering cavity and the ninth filtering cavity of the fourth filtering branch are in a row and are sequentially arranged along the first direction;

a third filtering cavity of the fourth filtering branch is respectively adjacent to the first filtering cavity, the second filtering cavity, the fourth filtering cavity and the fifth filtering cavity;

a seventh filtering cavity of the fourth filtering branch is respectively adjacent to a sixth filtering cavity, a fifth filtering cavity, an eighth filtering cavity, a ninth filtering cavity, a tenth filtering cavity and the first filtering cavity of the fifth filtering branch;

the first filtering cavity of the fifth filtering branch is respectively adjacent to the second filtering cavity, the fourth filtering cavity of the sixth filtering branch, the second common cavity, the sixth filtering cavity of the fourth filtering branch, the seventh filtering cavity and the tenth filtering cavity;

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

a fourth filtering cavity of the fifth filtering branch is respectively adjacent to a second filtering cavity, a third filtering cavity, a fifth filtering cavity, a seventh filtering cavity, an eighth filtering cavity and a fifth filtering cavity of the sixth filtering branch;

capacitive cross coupling is respectively performed between a first filtering cavity and a fourth filtering cavity, between a second filtering cavity and the fourth filtering cavity, between the fourth filtering cavity and a sixth filtering cavity, between the sixth filtering cavity and an eighth filtering cavity and between the sixth filtering cavity and a ninth filtering cavity of the fourth filtering branch circuit, so as to form five cross coupling zeros of the fourth filtering branch circuit;

inductive cross coupling is performed between a second filtering cavity and a fourth filtering cavity of the fifth filtering branch, capacitive cross coupling is performed between the fourth filtering cavity and a seventh filtering cavity, and between the fifth filtering cavity and the seventh filtering cavity respectively, so that three cross coupling zeros of the fifth filtering branch are formed;

and the first filtering cavity and the fourth filtering cavity of the sixth filtering branch are in capacitive cross coupling, and the first filtering cavity and the third filtering cavity are in inductive cross coupling, so that two cross coupling zeros of the sixth filtering branch are formed.

6. The filter of claim 5, further comprising:

a fifth port, a sixth port and a third common chamber connected to the fifth port, disposed on the housing;

the seventh filtering branch is coupled with the fifth port and consists of ten filtering cavities which are sequentially coupled, and five cross-coupling zeros are further formed by the ten filtering cavities of the seventh filtering branch;

the eighth filtering branch is respectively coupled with the third common cavity and the sixth port and consists of eight filtering cavities which are sequentially coupled, and the eight filtering cavities of the eighth filtering branch further form three cross-coupling zeros;

and the ninth filtering branch is coupled with the third common cavity and the sixth port respectively and consists of five filtering cavities which are sequentially coupled, and the five filtering cavities of the ninth filtering branch further form two cross-coupling zeros.

7. The filter of claim 6,

ten filter cavities of the seventh filter branch, eight filter cavities of the eighth filter branch, five filter cavities of the ninth filter branch and the third common cavity are divided into six rows arranged along the second direction;

the third filtering cavity, the fourth filtering cavity, the sixth filtering cavity and the seventh filtering cavity of the eighth filtering branch are in a row and are sequentially arranged along the first direction;

the second filtering cavity, the first filtering cavity, the fifth filtering cavity and the eighth filtering cavity of the eighth filtering branch are in a row and are sequentially arranged along the first direction;

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

a ninth filtering cavity, a tenth filtering cavity, a sixth filtering cavity of the seventh filtering branch, and a second filtering cavity and a third filtering cavity of the ninth filtering branch are in a row and are sequentially arranged along the first direction;

the eighth filtering cavity, the seventh filtering cavity, the fifth filtering cavity and the fourth filtering cavity of the seventh filtering branch are in a row and are sequentially arranged along the first direction;

the first filtering cavity, the second filtering cavity and the third filtering cavity of the seventh filtering branch are in a row and are sequentially arranged along the first direction;

the first filtering cavity of the eighth filtering branch is respectively adjacent to the second filtering cavity, the third filtering cavity, the fourth filtering cavity, the fifth filtering cavity and the third common cavity;

the eighth filtering cavity of the eighth filtering branch is respectively adjacent to the fifth filtering cavity, the sixth filtering cavity, the seventh filtering cavity and the fifth filtering cavity of the ninth filtering branch;

the first filter cavity of the ninth filter branch is respectively adjacent to the second filter cavity, the fifth filter cavity of the eighth filter branch, the third common cavity and the sixth filter cavity of the seventh filter branch;

a tenth filtering cavity of the seventh filtering branch is respectively adjacent to the ninth filtering cavity, the eighth filtering cavity, the seventh filtering cavity, the sixth filtering cavity and the third common cavity;

a fifth filtering cavity of the seventh filtering branch is respectively adjacent to a fourth filtering cavity, a second filtering cavity, a first filtering cavity, a seventh filtering cavity, a sixth filtering cavity and a second filtering cavity of the ninth filtering branch;

capacitive cross coupling is respectively performed between a first filtering cavity and a third filtering cavity, between the first filtering cavity and a fourth filtering cavity, between the fourth filtering cavity and a sixth filtering cavity, between the sixth filtering cavity and a ninth filtering cavity and between the seventh filtering cavity and the ninth filtering cavity of the seventh filtering branch circuit so as to form five cross coupling zeros of the seventh filtering branch circuit;

capacitive cross coupling is respectively performed between the first filtering cavity and the third filtering cavity and between the first filtering cavity and the fourth filtering cavity of the eighth filtering branch, and inductive cross coupling is performed between the sixth filtering cavity and the eighth filtering cavity to form three cross coupling zeros of the eighth filtering branch;

and the second filtering cavity and the fifth filtering cavity of the ninth filtering branch are in capacitive cross coupling, and the third filtering cavity and the fifth filtering cavity are in inductive cross coupling, so that two cross coupling zeros of the ninth filtering branch are formed.

8. The filter of claim 7, further comprising:

a seventh port, an eighth port, and a fourth common chamber connected to the seventh port, disposed on the housing;

a tenth filtering branch, coupled to the seventh port, and composed of ten filtering cavities coupled in sequence, where the ten filtering cavities of the tenth filtering branch further form five cross-coupling zeros;

the eleventh filtering branch is respectively coupled with the fourth common cavity and the eighth port and consists of eight filtering cavities which are sequentially coupled, and the eight filtering cavities of the eleventh filtering branch further form three cross-coupling zeros;

and the twelfth filtering branch is respectively coupled with the fourth common cavity and the eighth port and consists of five filtering cavities which are sequentially coupled, and the five filtering cavities of the twelfth filtering branch further form two cross-coupling zeros.

9. The filter of claim 8,

ten filter cavities of the tenth filter branch, eight filter cavities of the eleventh filter branch, five filter cavities of the twelfth filter branch and the fourth common cavity are divided into six columns arranged along the second direction;

the fourth filtering cavity, the sixth filtering cavity, the eighth filtering cavity and the ninth filtering cavity of the tenth filtering branch are in a row and are sequentially arranged along the first direction;

the third filtering cavity, the fifth filtering cavity, the seventh filtering cavity and the tenth filtering cavity of the tenth filtering branch are in a row and are sequentially arranged along the first direction;

the second filtering cavity of the tenth filtering branch, the second filtering cavity of the eleventh filtering branch, the first filtering cavity and the fourth common cavity are in a row and are sequentially arranged along the first direction;

the first filter cavity of the tenth filter branch, the third filter cavity of the eleventh filter branch, the first filter cavity of the twelfth filter branch and the second filter cavity of the twelfth filter branch are in a row and are sequentially arranged along the first direction;

a fifth filtering cavity and a fourth filtering cavity of the eleventh filtering branch, and a fourth filtering cavity and a third filtering cavity of the twelfth filtering branch are in a row and are sequentially arranged along the first direction;

a sixth filtering cavity, a seventh filtering cavity, an eighth filtering cavity of the eleventh filtering branch and a fifth filtering cavity of the twelfth filtering branch are in a row and are sequentially arranged along the first direction;

a fifth filtering cavity of the tenth filtering branch is respectively adjacent to a second filtering cavity, a third filtering cavity, a fourth filtering cavity, a sixth filtering cavity, a seventh filtering cavity and a second filtering cavity of the eleventh filtering branch;

a tenth filtering cavity of the tenth filtering branch is respectively adjacent to a ninth filtering cavity, an eighth filtering cavity, a seventh filtering cavity, a first filtering cavity of the eleventh filtering branch and the fourth common cavity;

the third filtering cavity of the eleventh filtering branch is respectively adjacent to the fourth filtering cavity, the first filtering cavity, the second filtering cavity, the first filtering cavity of the tenth filtering branch, the first filtering cavity of the twelfth filtering branch and the fourth filtering cavity;

a seventh filtering cavity of the eleventh filtering branch is respectively adjacent to the fourth filtering cavity, the fifth filtering cavity, the sixth filtering cavity and the eighth filtering cavity;

a third filtering cavity of the twelfth filtering branch is respectively adjacent to the first filtering cavity, the second filtering cavity, the fourth filtering cavity and the fifth filtering cavity;

capacitive cross coupling is respectively performed between a first filtering cavity and a third filtering cavity, between the first filtering cavity and a fourth filtering cavity, between the fourth filtering cavity and a sixth filtering cavity, between the sixth filtering cavity and an eighth filtering cavity and between the sixth filtering cavity and a ninth filtering cavity of the tenth filtering branch so as to form five cross coupling zeros of the tenth filtering branch;

inductive cross coupling is performed between a first filtering cavity and a third filtering cavity of the eleventh filtering branch, capacitive cross coupling is performed between a fourth filtering cavity and a seventh filtering cavity, and between a fifth filtering cavity and the seventh filtering cavity respectively, so that three cross coupling zeros of the eleventh filtering branch are formed;

and the first filtering cavity and the third filtering cavity of the twelfth filtering branch are inductively cross-coupled, and the first filtering cavity and the fourth filtering cavity are capacitively cross-coupled to form two cross-coupling zeros of the twelfth filtering branch.

10. A communication system, comprising a terminal and a base station, wherein the base station comprises a base station antenna and a radio frequency unit connected to the base station antenna, and wherein the radio frequency unit comprises a filter according to any one of claims 1 to 9, and wherein the filter is configured to filter a radio frequency signal.