CN113054334A

CN113054334A - Communication device and filter thereof

Info

Publication number: CN113054334A
Application number: CN201911380935.6A
Authority: CN
Inventors: 钟志波; 温世议; 张海峰; 周峰
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 device and a filter thereof, wherein the filter comprises a shell, a first side and a second side, wherein the first side and the second side are perpendicular to each other; a first common chamber disposed on the housing; the first filtering branch circuit is coupled with the first common cavity, consists of eleven filtering cavities which are sequentially coupled and forms five cross-coupling zeros; the second filtering branch circuit is coupled with the first common cavity, consists of eight filtering cavities which are sequentially coupled and forms three cross-coupling zeros; the third filtering branch is coupled with the first common cavity, is arranged adjacent to the second filtering branch, consists of eight filtering cavities which are sequentially coupled and forms a cross coupling zero point; and the fourth filtering branch is arranged adjacent to the first filtering branch and consists of nine filtering cavities which are sequentially coupled to form two cross-coupling zeros. The filter of this application is provided with first public chamber, can reduce the quantity of welding point and take a percentage, reduce cost improves the configuration flexibility.

Description

Communication device and filter thereof

Technical Field

The present application relates to the field of communications technologies, and in particular, to a communication device 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 includes not only the desired signal but also 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 when the existing filter comprises a plurality of branches, a plurality of signal input ends and signal output ends exist, so that the filter has a plurality of welding points and taps, the structure of the filter is complex, and the cost is high.

Disclosure of Invention

The application provides a communication device and a filter thereof, which are used for solving the problems of the filter in the prior art.

In order to solve the above technical problem, the present application provides a filter, including: a housing having a first direction and a second direction perpendicular to each other; a first common chamber disposed on the housing; the first filtering branch circuit is coupled with the first common cavity and consists of eleven filtering cavities which are sequentially coupled, and the eleven filtering cavities of the first filtering branch circuit form five cross-coupling zeros; the second filtering branch circuit is coupled with the first common cavity and consists of eight filtering cavities which are sequentially coupled, and the eight filtering cavities of the second filtering branch circuit form three cross-coupling zero points; the third filtering branch circuit is coupled with the first common cavity, is arranged adjacent to the second filtering branch circuit and consists of eight filtering cavities which are sequentially coupled, and the eight filtering cavities of the third filtering branch circuit form a cross-coupling zero point; and the fourth filtering branch is arranged adjacent to the first filtering branch and consists of nine filtering cavities which are sequentially coupled, and the nine filtering cavities of the fourth filtering branch form two cross-coupling zero points.

Optionally, the first common cavity and the first to eleventh filter cavities of the first filter branch are divided into two rows arranged along the second direction; the first common cavity, the second filtering cavity, the fourth filtering cavity, the sixth filtering cavity, the eighth filtering cavity and the tenth filtering cavity of the first filtering branch are in a row and are sequentially arranged along the first direction; the first filtering cavity, the third filtering cavity, the fifth filtering cavity, the seventh filtering cavity, the ninth filtering cavity and the eleventh filtering cavity of the first filtering branch are in a row and are sequentially arranged along the first direction; the third filter cavity of the first filter branch is further arranged adjacent to the second filter cavity and the fourth filter cavity of the first filter branch respectively; the sixth filter cavity of the first filter branch is further arranged adjacent to the fifth filter cavity and the seventh filter cavity of the first filter branch; and the ninth filtering cavity of the first filtering branch circuit is further arranged adjacent to the eighth filtering cavity and the tenth filtering cavity of the first filtering branch circuit. Through the mode, the first filtering branches are arranged regularly and distributed compactly, and layout and miniaturization are facilitated.

Optionally, capacitive cross coupling is respectively performed between the first filter cavity and the third filter cavity of the first filter branch, between the third filter cavity and the fifth filter cavity of the first filter branch, and between the fifth filter cavity and the seventh filter cavity of the first filter branch, so as to form three capacitive cross coupling zeros; and the seventh filtering cavity and the ninth filtering cavity of the first filtering branch circuit and the ninth filtering cavity and the eleventh filtering cavity of the first filtering branch circuit are inductively and cross-coupled respectively to form two inductive cross-coupling zeros. Through the mode, the first filtering branch comprises five cross-coupling zero points, zero point suppression can be realized, and debugging is facilitated.

Optionally, the first to eighth filter cavities of the second filter branch are divided into two rows arranged along the second direction; the first filtering cavity, the second filtering cavity, the fifth filtering cavity, the sixth filtering cavity and the eighth filtering cavity of the second filtering branch are in a row and are sequentially arranged along the first direction; the third filtering cavity, the fourth filtering cavity and the seventh filtering cavity of the second filtering branch are in a row and are sequentially arranged along the first direction; the second filter cavity of the second filter branch is further respectively adjacent to the first filter cavity, the third filter cavity, the fourth filter cavity and the fifth filter cavity of the second filter branch; and the sixth filtering cavity of the second filtering branch is further respectively adjacent to the fifth filtering cavity, the seventh filtering cavity and the eighth filtering cavity of the second filtering branch. Through the mode, the second filtering branches are arranged regularly and distributed compactly, and layout and miniaturization are facilitated.

Optionally, the inductive cross coupling is performed between the second filter cavity and the fourth filter cavity of the second filter branch, between the second filter cavity and the fifth filter cavity of the second filter branch, and between the sixth filter cavity and the eighth filter cavity of the second filter branch, respectively, to form three inductive cross coupling zeros. Through the mode, the second filtering branch comprises three cross-coupling zero points, so that zero point suppression can be realized, and debugging is facilitated; the second filtering branch circuit is in pure inductive cross coupling, so that the material consistency is good, and the stability is high.

Optionally, the first filter cavity and the second filter cavity of the third filter branch are sequentially separated from the central line of the housing in the second direction with respect to the first common cavity; the second filtering cavity to the eighth filtering cavity of the third filtering branch and the first filtering cavity to the eighth filtering cavity of the second filtering branch are divided into three rows arranged along the second direction; the first filtering cavity, the second filtering cavity, the fifth filtering cavity, the sixth filtering cavity and the eighth filtering cavity of the second filtering branch are in a row and are sequentially arranged along the first direction; the third filter cavity and the fourth filter cavity of the second filter branch, the fifth filter cavity of the third filter branch, the seventh filter cavity of the second filter branch and the eighth filter cavity of the third filter branch are in a row and are sequentially arranged along the first direction, wherein the eighth filter cavity of the second filter branch is far away from the center line of the shell in the second direction relative to the seventh filter cavity of the second filter branch; the second filtering cavity, the third filtering cavity, the fourth filtering cavity, the sixth filtering cavity and the seventh filtering cavity of the third filtering branch are in a row and are sequentially arranged along the first direction; the third filter cavity of the second filter branch is further respectively adjacent to the first filter cavity, the second filter cavity, the fourth filter cavity of the second filter branch, the third filter cavity of the third filter branch and the second filter cavity of the second filter branch; the seventh filtering cavity of the second filtering branch is further adjacent to the sixth filtering cavity, the eighth filtering cavity of the second filtering branch, the fifth filtering cavity, the sixth filtering cavity, the seventh filtering cavity and the eighth filtering cavity of the third filtering branch. Through the mode, the second filtering branch and the third filtering branch are arranged regularly and distributed compactly, and layout and miniaturization are facilitated.

Optionally, the fourth filter cavity and the sixth filter cavity of the third filter branch are capacitively cross-coupled to form a capacitive cross-coupling zero. Through the mode, the third filtering branch comprises the cross-coupling zero point, so that zero point suppression can be realized, and debugging is facilitated; and the third filtering branch circuit is in pure capacitive cross coupling, so that the material consistency is good and the stability is high.

Optionally, the first to ninth filter cavities of the fourth filter branch, the first to eleventh filter cavities of the first filter branch, and the first common cavity are divided into three rows arranged along the second direction; the first filtering cavity, the second filtering cavity, the third filtering cavity, the fourth filtering cavity, the fifth filtering cavity, the sixth filtering cavity and the seventh filtering cavity of the fourth filtering branch are in a row and are sequentially arranged along the first direction; the first common cavity, the second filtering cavity, the fourth filtering cavity, the sixth filtering cavity, the eighth filtering cavity, the tenth filtering cavity of the first filtering branch, the ninth filtering cavity and the eighth filtering cavity of the fourth filtering branch are in a row and are sequentially arranged along the first direction; the first filtering cavity, the third filtering cavity, the fifth filtering cavity, the seventh filtering cavity, the ninth filtering cavity and the eleventh filtering cavity of the first filtering branch are in a row and are sequentially arranged along the first direction; the first common cavity is further arranged adjacent to a first filter cavity of the fourth filter branch, a first filter cavity of the first filter branch, a second filter cavity of the first filter branch, a first filter cavity of the second filter branch and a first filter cavity of the third filter branch; the tenth filtering cavity of the first filtering branch is further respectively adjacent to the eleventh filtering cavity, the ninth filtering cavity of the first filtering branch, the seventh filtering cavity of the fourth filtering branch and the sixth filtering cavity of the fourth filtering branch; the ninth filter cavity of the fourth filter branch is further respectively adjacent to the seventh filter cavity, the sixth filter cavity of the fourth filter branch and the eleventh filter cavity of the first filter branch; the fourth filtering cavity of the first filtering branch is further respectively adjacent to the third filtering cavity and the fifth filtering cavity of the first filtering branch, and the third filtering cavity and the second filtering cavity of the fourth filtering branch. Through the mode, the first filtering branch and the fourth filtering branch are arranged regularly and distributed compactly, and layout and miniaturization are facilitated.

Optionally, the sixth filter cavity and the ninth filter cavity of the fourth filter branch are capacitively cross-coupled to form a capacitive cross-coupling zero; and the seventh filtering cavity and the ninth filtering cavity of the fourth filtering branch are inductively cross-coupled to form an inductive cross-coupling zero point. Through the mode, the fourth filtering branch comprises two cross-coupling zero points, zero point suppression can be realized, and debugging is facilitated.

In order to solve the above technical problem, the present application provides a communication device, where the communication device includes an antenna and a radio frequency unit connected to the antenna, the radio frequency unit includes any one of the above filters, and the filter is configured to filter the radio frequency signal.

Different from the prior art, the first filtering branch, the second filtering branch and the third filtering branch are connected through the common cavity, so that the number of welding points and taps can be reduced, and the size of the filter can be reduced; meanwhile, the four filtering branches are provided with cross-coupling zero points, so that zero point suppression can be realized for the four filtering branches, debugging is facilitated, and filtering signals of the four filtering branches are highly isolated; therefore, the size of the filter can be reduced, and the out-of-band rejection performance of the filter can be improved.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the description of the embodiments are briefly introduced 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 based on these drawings without creative efforts.

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

FIG. 2 is a schematic diagram of a topology of a first filtering branch of a filter according to the present application;

FIG. 3 is a schematic diagram of a topology of a second filtering branch of the filter of the present application;

FIG. 4 is a schematic diagram of a topology of a third filtering branch of the filter of the present application;

FIG. 5 is a schematic diagram of a topology of a fourth filtering branch of the filter of the present application;

FIG. 6 is a diagram illustrating simulation results of a first filtering branch of the filter according to the present application;

FIG. 7 is a diagram illustrating simulation results of a second filtering branch of the filter according to the present application;

FIG. 8 is a diagram illustrating simulation results of a third filtering branch of the filter according to the present application;

FIG. 9 is a diagram illustrating simulation results of a fourth filtering branch of the filter according to the present application;

fig. 10 is a schematic structural diagram of an embodiment of the communication device of the present application.

Detailed Description

In order to make those skilled in the art better understand the technical solution of the present application, the communication device and the filter thereof provided by the present invention are further described in detail below with reference to the accompanying drawings and the detailed description.

Fig. 1 to 5 show a schematic structure diagram of a filter according to an embodiment of the present application, fig. 2 shows a schematic topology structure diagram of a first filtering branch of the filter according to the present application, fig. 3 shows a schematic topology structure diagram of a second filtering branch of the filter according to the present application, fig. 4 shows a schematic topology structure diagram of a third filtering branch of the filter according to the present application, and fig. 5 shows a schematic topology structure diagram of a fourth filtering branch of the filter according to the present application.

As shown in fig. 1, the filter 10 of the present embodiment includes a housing 11, a first common cavity G1, a first filtering branch 12, a second filtering branch 13, a third filtering branch 14, and a fourth filtering branch 15. The first filtering branch 12, the second filtering branch 13, the third filtering branch 14 and the fourth filtering branch 15 may be a receiving filtering branch or a transmitting filtering branch, and are not limited herein.

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. And a first common chamber G1 provided on the housing 11. The first filtering branch 12 is coupled to the first common cavity G1 and is composed of eleven filtering cavities 121 coupled in sequence, and the eleven filtering cavities 121 of the first filtering branch 12 form five cross-coupling zeros 122. And the second filtering branch 13 is coupled with the first common cavity G1 and consists of eight filtering cavities 131 which are coupled in sequence, and the eight filtering cavities 131 of the second filtering branch 13 form three cross-coupling zeros 132. And the third filtering branch 14 is coupled with the first common cavity G1, is arranged adjacent to the second filtering branch 13, and consists of eight filtering cavities 141 coupled in sequence, and the eight filtering cavities 141 of the third filtering branch 14 form a cross-coupling zero point 142. The fourth filtering branch 15 is disposed adjacent to the first filtering branch 12, and is composed of nine filtering cavities 151 coupled in sequence, and the nine filtering cavities 151 of the fourth filtering branch 15 form two cross-coupling zeros 152.

The filter 10 includes a first common cavity G1, the first common cavity G1 is coupled to the first filter cavity T11 of the first filter branch 12, the first filter cavity R11 of the second filter branch 13, and the first filter cavity R21 of the third filter branch 14, respectively, so that the number of welding points and taps can be reduced, the cost is reduced, and the flexibility of configuration is improved.

Five cross coupling zero points 122 are formed on the first filtering branch 12, three cross coupling zero points 132 are formed on the second filtering branch 13, one cross coupling zero point 142 is formed on the third filtering branch 14, two cross coupling zero points 152 are formed on the fourth filtering branch 15, zero point suppression can be realized on each filtering branch, debugging indexes are facilitated, and isolation between corresponding pass bands of the four filtering branches can be improved.

Wherein the cross-coupling zero may also be 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 at the frequency point corresponding to the transmission zero cannot pass through the network, so that the complete isolation effect is achieved, the suppression effect on the signals outside the passband is achieved, and the high isolation among a plurality of passbands can be better achieved.

In particular, with continued reference to fig. 1, the first filter branch 12 includes a first filter cavity T11 through an eleventh filter cavity T111. In particular, the first common cavity G1, the first filter cavity T11 through the eleventh filter cavity T111 of the first filter branch 12 are divided into two columns arranged along the second direction D. The first common cavity G1, the second filter cavity T12, the fourth filter cavity T14, the sixth filter cavity T16, the eighth filter cavity T18 and the tenth filter cavity T110 of the first filter branch 12 are in a row and are sequentially arranged along the first direction L; the first filter cavity T11, the third filter cavity T13, the fifth filter cavity T15, the seventh filter cavity T17, the ninth filter cavity T19 and the eleventh filter cavity T111 of the first filter branch 12 are in a row and are sequentially arranged along the first direction L.

The third filter cavity T13 of the first filter branch 12 is further disposed adjacent to the second filter cavity T12 and the fourth filter cavity T14 of the first filter branch 12, respectively; the sixth filter cavity T16 of the first filter branch 12 is further disposed adjacent to the fifth filter cavity T15 and the seventh filter cavity T17 of the first filter branch 12; the ninth filter cavity T19 of the first filter branch 12 is further disposed adjacent to the eighth filter cavity T18 and the tenth filter cavity T110 of the first filter branch 12. As shown in fig. 1, the first filtering branch 12 is divided into two rows arranged along the second direction D, and the arrangement is regular, the distribution is compact, the layout and miniaturization are facilitated, and the stability is high.

In addition, the eighth filter cavity T18 of the first filter branch 12 is spaced apart from the tenth filter cavity T110 and the sixth filter cavity T16, respectively; the fourth filter cavity T14 of the first filter branch 12 is respectively arranged at an interval with the sixth filter cavity T16 and the second filter cavity T12; the ninth filter cavity T19 of the first filter branch 12 is spaced from the eleventh filter cavity T111 and the seventh filter cavity T17, respectively; the fifth filter cavity T15 of the first filter branch 12 is respectively arranged at intervals with the seventh filter cavity T17 and the third filter cavity T13; and the distances among the filter cavities are equal, so that the layout and debugging are facilitated.

The first filter cavity T11 of the first filter branch 12 is further spaced apart from the third filter cavity T13 of the first filter branch 12, and is adjacent to the second filter cavity T12 of the first filter branch 12, the first common cavity G1, and the first filter cavity R21 of the third filter branch 14.

As shown in fig. 2, capacitive cross-coupling is performed between the first filter cavity T11 and the third filter cavity T13 of the first filter branch 12, between the third filter cavity T13 and the fifth filter cavity T15 of the first filter branch 12, and between the fifth filter cavity T15 and the seventh filter cavity T17 of the first filter branch 12, respectively, so as to form three capacitive cross-coupling zeros.

Specifically, in the first filtering branch 12, windows may be respectively disposed between the first filtering cavity T11 and the third filtering cavity T13, between the third filtering cavity T13 and the fifth filtering cavity T15, and between the fifth filtering cavity T15 and the seventh filtering cavity T17, so that capacitive cross-coupling is respectively achieved between the first filtering cavity T11 and the third filtering cavity T13, between the third filtering cavity T13 and the fifth filtering cavity T15, and between the fifth filtering cavity T15 and the seventh filtering cavity T17, and a capacitive cross-coupling zero point is formed.

In some embodiments, capacitive zero coupling may also be achieved by providing capacitive cross-coupling elements. The capacitive cross-coupling element may be a flying bar, that is, a flying bar may be respectively disposed between the first filter cavity T11 and the third filter cavity T13, between the third filter cavity T13 and the fifth filter cavity T15, and between the fifth filter cavity T15 and the seventh filter cavity T17.

Inductive cross-coupling is respectively performed between the seventh filter cavity T17 and the ninth filter cavity T19 of the first filter branch 12 and between the ninth filter cavity T19 and the eleventh filter cavity T111 of the first filter branch 12 to form two inductive cross-coupling zeros.

Specifically, in the first filtering branch 12, windows may be respectively disposed between the seventh filtering cavity T17 and the ninth filtering cavity T19, and between the ninth filtering cavity T19 and the eleventh filtering cavity T111, and metal coupling ribs are disposed at the windows, so that inductive cross coupling is respectively achieved between the seventh filtering cavity T17 and the ninth filtering cavity T19, and between the ninth filtering cavity T19 and the eleventh filtering cavity T111, so as to form inductive cross coupling zeros.

Capacitive cross coupling is equivalent to connecting capacitors between the first filter cavity T11 and the third filter cavity T13, between the third filter cavity T13 and the fifth filter cavity T15, and between the fifth filter cavity T15 and the seventh filter cavity T17 respectively; the inductive cross coupling is equivalent to connecting inductors between the seventh filter cavity T17 and the ninth filter cavity T19 and between the ninth filter cavity T19 and the eleventh filter cavity T111 respectively; the inductive cross coupling and the capacitive cross coupling can realize zero point suppression, so that the debugging index is convenient, and the designed filter meets the parameter requirement.

The size of the first common cavity G1 is the same as the size of the first filtering cavity T11 to the eleventh filtering cavity T111 of the first filtering branch 12, so that the layout and debugging are facilitated, the space utilization rate is improved, the size is reduced, and the consistency of the filter 10 is improved.

With continued reference to fig. 1, the second filter branch 13 includes first through eighth filter cavities R11 through R18. The first filter cavity R11 through the eighth filter cavity R18 of the second filter branch 13 are divided into two rows arranged along the second direction D; the first filter cavity R11, the second filter cavity R12, the fifth filter cavity R15, the sixth filter cavity R16 and the eighth filter cavity R18 of the second filter branch 13 are in a row and are sequentially arranged along the first direction L; the third filter cavity R13, the fourth filter cavity R14 and the seventh filter cavity R17 of the second filter branch 13 are in a row and are sequentially arranged along the first direction L.

The second filter cavity R12 of the second filter branch 13 is further disposed adjacent to the first filter cavity R11, the third filter cavity R13, the fourth filter cavity R14 and the fifth filter cavity R15 of the second filter branch 13, respectively; the sixth filter cavity R16 of the second filter branch 13 is further disposed adjacent to the fifth filter cavity R15, the seventh filter cavity R17 and the eighth filter cavity R18 of the second filter branch 13, respectively. As shown in fig. 1, the second filtering branches 13 are divided into two rows arranged along the second direction D, and the filtering cavities of the second filtering branches 13 are regularly arranged, so that the distribution is compact, and the layout and miniaturization are facilitated.

Inductive cross coupling is respectively performed between the second filter cavity R12 and the fourth filter cavity R14 of the second filter branch 13, between the second filter cavity R12 and the fifth filter cavity R15 of the second filter branch 13, and between the sixth filter cavity R16 and the eighth filter cavity R18 of the second filter branch 13, so as to form three inductive cross coupling zeros.

As shown in fig. 3, the three cross-coupling zeros 132 in the second filtering branch 13 are all inductive cross-coupling zeros, so that the second filtering branch 13 is purely inductive cross-coupled, that is, metal coupling ribs are respectively disposed between the second filtering cavity R12 and the fourth filtering cavity R14, between the second filtering cavity R12 and the fifth filtering cavity R15, and between the sixth filtering cavity R16 and the eighth filtering cavity R18, which can reduce the complexity of the product, and has good material consistency and high stability; the metal coupling rib is slightly changed by the external temperature, so that the temperature drift is avoided.

With continued reference to fig. 1, the third filter branch 14 includes first through eighth filter cavities R21 through R28. The first filter cavity R21 and the second filter cavity R22 of the third filter branch 14 are sequentially away from the first common cavity G1 toward the bisector MM' of the housing 11 in the second direction D; the second through eighth filter cavities R22 through R28 of the third filter branch 14 and the first through eighth filter cavities R11 through R18 of the second filter branch 13 are divided into three rows arranged along the second direction D.

The first filter cavity R11, the second filter cavity R12, the fifth filter cavity R15, the sixth filter cavity R16 and the eighth filter cavity R18 of the second filter branch 13 are in a row and are sequentially arranged along the first direction L; the third filter cavity R13, the fourth filter cavity R14, the fifth filter cavity R25 of the third filter branch 14, the seventh filter cavity R17 of the second filter branch 13, and the eighth filter cavity R28 of the third filter branch 14 are arranged in a row in sequence along the first direction L, wherein the eighth filter cavity R18 of the second filter branch 13 is far away from the mid-parting MM' of the housing 11 in the second direction D relative to the seventh filter cavity R17 of the second filter branch 13; the second filter cavity R22, the third filter cavity R23, the fourth filter cavity R24, the sixth filter cavity R26 and the seventh filter cavity R27 of the third filter branch 14 are in a row and are sequentially arranged along the first direction L.

The third filter cavity R13 of the second filter branch 13 is further disposed adjacent to the first filter cavity R11, the second filter cavity R12, the fourth filter cavity R14, the third filter cavity R23 of the third filter branch 14, and the second filter cavity R22 of the second filter branch 13, respectively; the seventh filtering cavity R17 of the second filtering branch 13 is further disposed adjacent to the sixth filtering cavity R16, the eighth filtering cavity R18 of the second filtering branch 13, the fifth filtering cavity R25, the sixth filtering cavity R26, the seventh filtering cavity R27 and the eighth filtering cavity R28 of the third filtering branch 14, as shown in fig. 1, the second filtering branch 13 and the third filtering branch 14 are substantially divided into three rows arranged along the second direction D, the filtering cavities are arranged regularly and distributed compactly, and layout and miniaturization are facilitated.

As shown in fig. 4, the fourth R24 and sixth R26 filter cavities of the third filter branch 14 are capacitively cross-coupled to form a capacitive cross-coupling zero. Therefore, the third filtering branch 14 is purely capacitively cross-coupled, the material consistency is good, the stability is high, and the production cost can be reduced.

With continued reference to fig. 1, the fourth filter branch 15 includes first through ninth filter cavities T21-T29. The first filter cavity T21 through the ninth filter cavity T29 of the fourth filter branch 15, the first filter cavity T11 through the eleventh filter cavity T111 of the first filter branch 12, and the first common cavity G1 are divided into three rows arranged along the second direction D.

The first filtering cavity T21, the second filtering cavity T22, the third filtering cavity T23, the fourth filtering cavity T24, the fifth filtering cavity T25, the sixth filtering cavity T26 and the seventh filtering cavity T27 of the fourth filtering branch 15 are in a row and are sequentially arranged along the first direction L; the first common cavity G1, the second filter cavity T12, the fourth filter cavity T14, the sixth filter cavity T16, the eighth filter cavity T18, the tenth filter cavity T110, the ninth filter cavity T29 and the eighth filter cavity T28 of the fourth filter branch circuit 15 are in a row and are sequentially arranged along the first direction L; the first filter cavity T11, the third filter cavity T13, the fifth filter cavity T15, the seventh filter cavity T17, the ninth filter cavity T19 and the eleventh filter cavity T111 of the first filter branch 12 are in a row and are sequentially arranged along the first direction L.

The first common cavity G1 is further disposed adjacent to the first filter cavity T21 of the fourth filter branch 15, the first filter cavity T11 of the first filter branch 12, the second filter cavity T12, the first filter cavity R11 of the second filter branch 13, and the first filter cavity R21 of the third filter branch 14; the tenth filter cavity T110 of the first filter branch 12 is further disposed adjacent to the eleventh filter cavity T111, the ninth filter cavity T19 of the first filter branch 12, the seventh filter cavity T27 of the fourth filter branch 15, and the sixth filter cavity T26, respectively; the ninth filter cavity T29 of the fourth filter branch 15 is further disposed adjacent to the seventh filter cavity T27, the sixth filter cavity T26 of the fourth filter branch 15, and the eleventh filter cavity T111 of the first filter branch 12, respectively; the fourth filter cavity T14 of the first filter branch 12 is further disposed adjacent to the third filter cavity T13 of the first filter branch 12, the fifth filter cavity T15 of the first filter branch, and the third filter cavity T23 and the second filter cavity T22 of the fourth filter branch 15, respectively.

Further, a sixth filtering cavity T26 of the fourth filtering branch 15 is respectively arranged at intervals with a seventh filtering cavity T27 and a fifth filtering cavity T25, a fourth filtering cavity T24 of the fourth filtering branch 15 is respectively arranged at intervals with a fifth filtering cavity T25 and a third filtering cavity T23, a second filtering cavity T22 of the fourth filtering branch 15 is respectively arranged at intervals with a third filtering cavity T23 and a first filtering cavity T21, and a ninth filtering cavity T29 of the fourth filtering branch 15 is respectively arranged at intervals with an eighth filtering cavity T28 of the fourth filtering branch 15 and a tenth filtering cavity T110 of the first filtering branch 12.

As shown in fig. 1, the first filtering branch 12 and the fourth filtering branch 15 are disposed adjacent to each other, the second filtering branch 13 and the third filtering branch 14 are disposed adjacent to each other, and the four filtering branches are integrally arranged in the first direction L, so that the size of the filter 10 in the second direction D can be reduced, and the filtering cavities are regularly arranged and compactly distributed, thereby facilitating layout and miniaturization.

As shown in fig. 5, the sixth filter cavity T26 of the fourth filter branch 15 is capacitively cross-coupled with the ninth filter cavity T29 to form a capacitive cross-coupling zero; the seventh filter cavity T27 of the fourth filter branch 15 is inductively cross-coupled with the ninth filter cavity T29 to form an inductive cross-coupling zero.

In addition, part of the adjacent filter cavities are intersected, as shown in fig. 1. For example, the first common cavity G1 is respectively intersected with the first filter cavity T21 of the fourth filter branch 15, the first filter cavity T11 of the first filter branch 12, the first filter cavity T11 of the second filter branch 13, and the first filter cavity T21 of the third filter branch 14; the first filter cavity R21 of the third filter branch 14 intersects the second filter cavity R22.

Taking the first filter cavity R21 and the second filter cavity R22 of the third filter branch 14 as an example, the first filter cavity R21 and the second filter cavity R22 are disposed in an intersecting manner to form two intersecting points; between the first R21 and the second R22 there is arranged a window having a width equal to the distance between the two intersections. The distance between the two filter cavities can be reduced and the coupling is strengthened by the crossed arrangement of the filter cavities; the method that a separation wall needs to be arranged between two filter cavities which are sequentially coupled in the traditional filter and then a coupling window is arranged on the separation wall is avoided, materials are reduced, and the processing is convenient.

In this embodiment, the filter includes a first common cavity disposed on the housing; the first filtering branch circuit is coupled with the first common cavity, consists of eleven filtering cavities which are sequentially coupled and forms five cross-coupling zeros; the second filtering branch circuit is coupled with the first common cavity, consists of eight filtering cavities which are sequentially coupled and forms three cross-coupling zeros; the third filtering branch is coupled with the first common cavity, is arranged adjacent to the second filtering branch, consists of eight filtering cavities which are sequentially coupled and forms a cross coupling zero point; the fourth filtering branch is arranged adjacent to the first filtering branch and consists of nine filtering cavities which are sequentially coupled to form two cross-coupling zero points; the filter is provided with the first common cavity, so that the number of welding points and taps can be reduced, the cost is reduced, and the configuration flexibility is improved; each filter cavity branch is provided with a coupling zero, so that zero suppression can be realized, and debugging is facilitated; the filtered signals of the four filtering branches can be kept highly isolated.

Referring to fig. 6 to 9, fig. 6 is a schematic diagram of simulation results of a first filtering branch of the filter of the present application, fig. 7 is a schematic diagram of simulation results of a second filtering branch of the filter of the present application, fig. 8 is a schematic diagram of simulation results of a third filtering branch of the filter of the present application, and fig. 9 is a schematic diagram of simulation results of a fourth filtering branch of the filter of the present application.

In this embodiment, the first filtering branch 12 and the fourth filtering branch 15 are transmitting filtering branches, and the second filtering branch 13 and the third filtering branch 14 are receiving filtering branches.

The bandwidth of the first filtering branch 12 is in the range 1804Mhz to 1881 Mhz. In particular, in the first filtering branch 12, the coupling bandwidth between the input (i.e. the first common cavity G1) and the first filtering cavity T11 ranges from 62.8Mhz to 74 Mhz; the coupling bandwidth between the first filter cavity T11 and the second filter cavity T12 ranges from 49.3Mhz to 59 Mhz; the coupling bandwidth between the first filter cavity T11 and the third filter cavity T13 ranges from-15.1 Mhz to-21 Mhz; the coupling bandwidth between the second filter cavity T12 and the third filter cavity T13 ranges from 34Mhz to 42 Mhz; the coupling bandwidth between the third filter cavity T13 and the fourth filter cavity T14 ranges from 31.3Mhz to 39 Mhz; the coupling bandwidth between the third filter cavity T13 and the fifth filter cavity T15 ranges from-10.6 Mhz to-16 Mhz; the coupling bandwidth between the fourth filter cavity T14 and the fifth filter cavity T15 ranges from 30.4Mhz to 38 Mhz; the coupling bandwidth between the fifth filter cavity T15 and the sixth filter cavity T16 ranges from 29.5Mhz to 37 Mhz; the coupling bandwidth between the fifth filter cavity T15 and the seventh filter cavity T17 ranges from-11.5 Mhz to-17 Mhz; the coupling bandwidth between the sixth filter cavity T16 and the seventh filter cavity T17 ranges from 30.4Mhz to 38 Mhz; the coupling bandwidth range between the seventh filter cavity T17 and the eighth filter cavity T18 is 32.2 Mhz-40 Mhz; the coupling bandwidth between the seventh filter cavity T17 and the ninth filter cavity T19 ranges from 6.1Mhz to 11 Mhz; the coupling bandwidth between the eighth filter cavity T18 and the ninth filter cavity T19 ranges from 33.1Mhz to 41 Mhz; the coupling bandwidth between the ninth filter cavity T19 and the tenth filter cavity T110 ranges from 33.1Mhz to 41 Mhz; the coupling bandwidth between the ninth filter cavity T19 and the eleventh filter cavity T111 ranges from 16Mhz to 22 Mhz; the coupling bandwidth between the tenth filter cavity T110 and the eleventh filter cavity T111 ranges from 48.4Mhz to 58 Mhz; the coupling bandwidth range between the eleventh filter cavity T111 and the output end is 62.8 Mhz-74 Mhz; therefore, the bandwidth of the first filtering branch 12 of the filter 10 of the present embodiment is located at 1804Mhz to 1881Mhz, which can meet the design requirement.

Therefore, the resonant frequencies of the first filter cavity T11 through the eleventh filter cavity T111 of the first filter branch 12 are sequentially located in the following ranges: 1841 Mhz-1843 Mhz, 1827 Mhz-1829 Mhz, 1843 Mhz-1845 Mhz, 1827 Mhz-1829 Mhz, 1841 Mhz-1843 Mhz, 1825 Mhz-1827 Mhz, 1840 Mhz-1842 Mhz, 1850 Mhz-1852 Mhz, 1839 Mhz-1841 Mhz, 1856 Mhz-1858 Mhz, and 1841 Mhz-1843 Mhz. Therefore, the resonant frequencies of the filter cavities are basically the same, and the convenience of manufacturing and debugging is improved; the method can be manufactured by adopting the same specification parameters, and the required parameter range can be reached only by simple debugging in the actual process.

The bandwidth of the first filtering branch 12 is in the range 1804Mhz to 1881Mhz, as shown in a frequency band curve 20 in fig. 6, and five coupling zeros are formed, and the bandwidth rejection of the first filtering branch 12 satisfies the following parameters:

the bandwidth of the second filter branch 13 is in the range of 1709Mhz to 1786 Mhz. In particular, in the second filtering branch 13, the coupling bandwidth between the input (i.e. the first common cavity G1) and the first filtering cavity R11 ranges from 63.7Mhz to 75 Mhz; the coupling bandwidth between the first filter cavity R11 and the second filter cavity R12 ranges from 52.9Mhz to 63 Mhz; the coupling bandwidth between the second filter cavity R12 and the third filter cavity R13 ranges from 27.7Mhz to 35 Mhz; the coupling bandwidth between the second filter cavity R12 and the fourth filter cavity R14 ranges from 23.2Mhz to 30 Mhz; the coupling bandwidth between the second filter cavity R12 and the fifth filter cavity R15 ranges from 2.5Mhz to 7 Mhz; the coupling bandwidth between the third filter cavity R13 and the fourth filter cavity R14 ranges from 21.4Mhz to 28 Mhz; the coupling bandwidth between the fourth filter cavity R14 and the fifth filter cavity R15 ranges from 34Mhz to 42 Mhz; the coupling bandwidth between the fifth filter cavity R15 and the sixth filter cavity R16 ranges from 34.9Mhz to 43 Mhz; the coupling bandwidth between the sixth filter cavity R16 and the seventh filter cavity R17 ranges from 29.5Mhz to 37 Mhz; the coupling bandwidth between the sixth filter cavity R16 and the eighth filter cavity R18 ranges from 25.9Mhz to 33 Mhz; the coupling bandwidth between the seventh filter cavity R17 and the eighth filter cavity R18 ranges from 44.8Mhz to 54 Mhz; the coupling bandwidth range between the eighth filter cavity R18 and the output end is 63.7 Mhz-75 Mhz; therefore, the bandwidth of the second filtering branch 13 of the filter 10 of the present embodiment is 1709Mhz to 1786Mhz, which can meet the design requirement.

Therefore, the resonant frequencies of the first filter cavity R11 through the eighth filter cavity R18 of the second filter branch 13 are sequentially located in the following ranges: 1745 Mhz-1747 Mhz, 1772 Mhz-1774 Mhz, 1747 Mhz-1749 Mhz, 1744 Mhz-1746 Mhz, 1742 Mhz-1744 Mhz, 1767 Mhz-1769 Mhz, 1745 Mhz-1747 Mhz. Therefore, the resonant frequencies of the filter cavities are basically the same, and the convenience of manufacturing and debugging is improved; the method can be manufactured by adopting the same specification parameters, and the required parameter range can be reached only by simple debugging in the actual process.

The bandwidth of the second filtering branch 13 is in the range of 1709Mhz to 1786Mhz, as shown in the frequency band curve 30 in fig. 7, and three coupling zeros are formed, and the bandwidth rejection of the second filtering branch 13 satisfies the following parameters:

frequency (MHz)
		1420～1605	≥50dB
1605～1670	≥35dB
		1670～1690	≥15dB
1690～1695	≥10dB
		1805～1825	≥75dB
1825～1880	≥85dB
		1880～1900	≥25dB
2000～2020	≥20dB

The bandwidth of the third filtering branch 14 is in the range 1919Mhz to 1981 Mhz. In particular, in the third filtering branch 14, the coupling bandwidth between the input (i.e. the first common cavity G1) and the first filtering cavity R21 ranges from 50.2Mhz to 60 Mhz; the coupling bandwidth between the first filter cavity R21 and the second filter cavity R22 ranges from 42.1Mhz to 51 Mhz; the coupling bandwidth between the second filter cavity R22 and the third filter cavity R23 ranges from 29.5Mhz to 37 Mhz; the coupling bandwidth between the third filter cavity R23 and the fourth filter cavity R24 ranges from 27.7Mhz to 35 Mhz; the coupling bandwidth between the fourth filter cavity R24 and the fifth filter cavity R25 ranges from 25.9Mhz to 33 Mhz; the coupling bandwidth between the fourth filter cavity R24 and the sixth filter cavity R26 ranges from-6.1 Mhz to-11 Mhz; the coupling bandwidth between the fifth filter cavity R25 and the sixth filter cavity R26 ranges from 25.9Mhz to 33 Mhz; the coupling bandwidth between the sixth filter cavity R26 and the seventh filter cavity R27 ranges from 29.5Mhz to 37 Mhz; the coupling bandwidth between the seventh filter cavity R27 and the eighth filter cavity R28 ranges from 42.1Mhz to 51 Mhz; the coupling bandwidth range between the eighth filter cavity R28 and the output end is 50.2 Mhz-60 Mhz; therefore, the bandwidth of the third filtering branch 14 of the filter 10 of the present embodiment is 1919 Mhz-1981 Mhz, which can meet the design requirement.

Therefore, the resonant frequencies of the first filter cavity R21 through the eighth filter cavity R28 of the third filter branch 14 are sequentially in the following ranges: 1948 Mhz-1950 Mhz, 1949 Mhz-1951 Mhz, 1939 Mhz-1941 Mhz, 1948 Mhz-1950 Mhz, and 1948 Mhz-1950 Mhz. Therefore, the resonant frequencies of the filter cavities are basically the same, and the convenience of manufacturing and debugging is improved; the method can be manufactured by adopting the same specification parameters, and the required parameter range can be reached only by simple debugging in the actual process.

The bandwidth of the third filtering branch 14 is in the range of 1919 Mhz-1981 Mhz, as shown by the frequency band curve 40 in fig. 8, and a coupling zero is formed, and the bandwidth rejection of the third filtering branch 14 satisfies the following parameters:

frequency (MHz)
		1805～1825	≥75dB
1825～1880	≥85dB
		1880～1900	≥25dB
2000～2020	≥20dB
		2100～2110	≥49dB

The bandwidth of the fourth filtering branch 15 is in the range of 2109 Mhz-2171 Mhz. Specifically, in the fourth filtering branch 15, the coupling bandwidth between the input end and the first filtering cavity T21 ranges from 50.2Mhz to 60 Mhz; the coupling bandwidth between the first filter cavity T21 and the second filter cavity T22 ranges from 42.1Mhz to 51 Mhz; the coupling bandwidth between the second filter cavity T22 and the third filter cavity T23 ranges from 28.6Mhz to 36 Mhz; the coupling bandwidth between the third filter cavity T23 and the fourth filter cavity T24 ranges from 26.8Mhz to 34 Mhz; the coupling bandwidth between the fourth filter cavity T24 and the fifth filter cavity T25 ranges from 25.9Mhz to 33 Mhz; the coupling bandwidth between the fifth filter cavity T25 and the sixth filter cavity T26 ranges from 25.9Mhz to 33 Mhz; the coupling bandwidth range between the sixth filter cavity T26 and the seventh filter cavity T27 is 23.2 Mhz-30 Mhz; the coupling bandwidth between the sixth filter cavity T26 and the ninth filter cavity T29 ranges from-11.5 Mhz to-17 Mhz; the coupling bandwidth between the seventh filter cavity T27 and the eighth filter cavity T28 ranges from 37.6Mhz to 46 Mhz; the coupling bandwidth between the seventh filter cavity T27 and the ninth filter cavity T29 ranges from-1.1 Mhz to 3 Mhz; the coupling bandwidth between the eighth filter cavity T28 and the ninth filter cavity T29 ranges from 39.4Mhz to 48 Mhz; the coupling bandwidth range between the ninth filter cavity T29 and the output end is 50.2 Mhz-60 Mhz; therefore, the bandwidth of the fourth filtering branch 15 of the filter 10 of the present embodiment is between 2109Mhz and 2171Mhz, which can meet the design requirement.

Therefore, the resonant frequencies of the first filter cavity T21 through the ninth filter cavity T29 of the fourth filter branch 15 are sequentially located in the following ranges: 2138Mhz to 2140Mhz, 2139Mhz to 2141Mhz, and 2138Mhz to 2140 Mhz. Therefore, the resonant frequencies of the filter cavities are basically the same, and the convenience of manufacturing and debugging is improved; the method can be manufactured by adopting the same specification parameters, and the required parameter range can be reached only by simple debugging in the actual process.

The bandwidth of the fourth filtering branch 15 is in the range of 2109Mhz to 2171Mhz, as shown in the frequency band curve 50 in fig. 9, and two coupling zeros are formed, and the bandwidth rejection of the fourth filtering branch 15 satisfies the following parameters:

frequency (MHz)
		1990～2025	≥80dB
2025～2095	≥19dB
		2095～2100	≥15dB
2100～2103.5	≥15-3.4*(f-2100)dB
		2103.5～2105	≥2dB
2175～2176.5	≥2dB
		2176.5～2180	≥15-3.4*(2180-f)dB
2180～2240	≥15dB
		2240～2280	≥41dB
2280～2300	≥41dB
		2300～2320	≥80dB
2320～2500	≥88dB

As can be seen from the above description, the bandwidth of the first filtering branch 12 is in the range of 1804Mhz to 1881Mhz, the bandwidth of the second filtering branch 13 is in the range of 1709Mhz to 1786Mhz, the bandwidth of the third filtering branch 14 is in the range of 1919Mhz to 1981Mhz, the bandwidth of the fourth filtering branch 15 is in the range of 2109Mhz to 2171Mhz, and the four filtering branches are in different bandwidth ranges and do not interfere with each other, so that the first signal of the first filtering branch 12, the second signal of the second filtering branch 13, the third signal of the third filtering branch 14, and the fourth signal of the fourth filtering branch 15 of the filter 10 of this embodiment are highly isolated from each other, thereby improving the out-of-band rejection performance of the filter 10.

Referring to fig. 10, fig. 10 is a schematic structural diagram of an embodiment of a communication device of the present application. The communication device 60 may include an antenna 61 and a Radio frequency Unit 62(Remote Radio Unit, RRU) connected to the antenna 61, where the Radio frequency Unit 62 includes the filter 10 shown in the above embodiment, and the filter 10 may be used to filter a Radio frequency signal. Therefore, the bandwidth of the first frequency band signal of the communication device 60 can be set to be 1804Mhz to 1881Mhz, the bandwidth of the second frequency band signal can be set to be 1709Mhz to 1786Mhz, the bandwidth of the third frequency band signal can be set to be 1919Mhz to 1981Mhz, and the bandwidth of the fourth frequency band signal can be set to be 2109Mhz to 2171Mhz, which can meet the design requirement.

The communication device 60 may be a base station through which a terminal may communicate with other terminals. In other embodiments, the rf Unit 62 and the Antenna 61 may be designed integrally to form an Active Antenna Unit (AAU).

Some embodiments of the present application are filters, which may also be referred to as combiners, i.e., dual-frequency combiners. It is understood that in other embodiments, the duplexer may be referred to as a duplexer.

It is to be understood that the specific embodiments described herein are merely illustrative of the application and are not limiting of the application. In addition, for convenience of description, only a part of structures related to the present application, not all of the structures, are shown in the drawings. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

The terms "first", "second", etc. in this application are used to distinguish between different objects and not to describe a particular order. Furthermore, the terms "include" and "have," as well as any variations thereof, are intended to cover non-exclusive inclusions. For example, a process, method, system, article, or apparatus that comprises a list of steps or elements is not limited to only those steps or elements listed, but may alternatively include other steps or elements not listed, or inherent to such process, method, article, or apparatus.

Reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the application. The appearances of the phrase in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. It is explicitly and implicitly understood by one skilled in the art that the embodiments described herein can be combined with other embodiments.

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

Claims

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

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

a first common chamber disposed on the housing;

the first filtering branch circuit is coupled with the first common cavity and consists of eleven filtering cavities which are sequentially coupled, and the eleven filtering cavities of the first filtering branch circuit form five cross-coupling zeros;

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

the third filtering branch circuit is coupled with the first common cavity, is arranged adjacent to the second filtering branch circuit and consists of eight filtering cavities which are sequentially coupled, and the eight filtering cavities of the third filtering branch circuit form a cross-coupling zero point;

and the fourth filtering branch is arranged adjacent to the first filtering branch and consists of nine filtering cavities which are sequentially coupled, and the nine filtering cavities of the fourth filtering branch form two cross-coupling zero points.

2. The filter of claim 1,

the first common cavity and the first filtering cavity to the eleventh filtering cavity of the first filtering branch circuit are divided into two rows arranged along the second direction;

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

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

the third filter cavity of the first filter branch is further arranged adjacent to the second filter cavity and the fourth filter cavity of the first filter branch respectively; the sixth filter cavity of the first filter branch is further arranged adjacent to the fifth filter cavity and the seventh filter cavity of the first filter branch; and the ninth filtering cavity of the first filtering branch circuit is further arranged adjacent to the eighth filtering cavity and the tenth filtering cavity of the first filtering branch circuit.

3. The filter of claim 2,

capacitive cross coupling is respectively performed between a first filtering cavity and a third filtering cavity of the first filtering branch, between the third filtering cavity and a fifth filtering cavity of the first filtering branch, and between the fifth filtering cavity and a seventh filtering cavity of the first filtering branch so as to form three capacitive cross coupling zeros;

and the seventh filtering cavity and the ninth filtering cavity of the first filtering branch circuit and the ninth filtering cavity and the eleventh filtering cavity of the first filtering branch circuit are inductively and cross-coupled respectively to form two inductive cross-coupling zeros.

4. The filter of claim 3,

the first filtering cavity to the eighth filtering cavity of the second filtering branch circuit are divided into two rows arranged along the second direction;

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

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

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

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

5. The filter of claim 4,

and the inductive cross coupling is respectively performed between the second filtering cavity and the fourth filtering cavity of the second filtering branch, between the second filtering cavity and the fifth filtering cavity of the second filtering branch, and between the sixth filtering cavity and the eighth filtering cavity of the second filtering branch, so as to form three inductive cross coupling zeros.

6. The filter of claim 5,

the first filtering cavity and the second filtering cavity of the third filtering branch are sequentially far away from the middle branching line of the shell in the second direction relative to the first common cavity; the second filtering cavity to the eighth filtering cavity of the third filtering branch and the first filtering cavity to the eighth filtering cavity of the second filtering branch are divided into three rows arranged along the second direction;

the third filter cavity and the fourth filter cavity of the second filter branch, the fifth filter cavity of the third filter branch, the seventh filter cavity of the second filter branch and the eighth filter cavity of the third filter branch are in a row and are sequentially arranged along the first direction, wherein the eighth filter cavity of the second filter branch is far away from the center line of the shell in the second direction relative to the seventh filter cavity of the second filter branch;

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

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

the seventh filtering cavity of the second filtering branch is further adjacent to the sixth filtering cavity, the eighth filtering cavity of the second filtering branch, the fifth filtering cavity, the sixth filtering cavity, the seventh filtering cavity and the eighth filtering cavity of the third filtering branch.

7. The filter of claim 6,

and the fourth filter cavity and the sixth filter cavity of the third filter branch are capacitively cross-coupled to form a capacitive cross-coupling zero point.

8. The filter of claim 7,

the first filtering cavity to the ninth filtering cavity of the fourth filtering branch, the first filtering cavity to the eleventh filtering cavity of the first filtering branch and the first common cavity are divided into three rows arranged along the second direction;

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

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

the first common cavity is further arranged adjacent to a first filter cavity of the fourth filter branch, a first filter cavity of the first filter branch, a second filter cavity of the first filter branch, a first filter cavity of the second filter branch and a first filter cavity of the third filter branch;

the tenth filtering cavity of the first filtering branch is further respectively adjacent to the eleventh filtering cavity, the ninth filtering cavity of the first filtering branch, the seventh filtering cavity of the fourth filtering branch and the sixth filtering cavity of the fourth filtering branch;

the ninth filter cavity of the fourth filter branch is further respectively adjacent to the seventh filter cavity, the sixth filter cavity of the fourth filter branch and the eleventh filter cavity of the first filter branch;

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

9. The filter according to any one of claims 1 to 8,

the sixth filter cavity and the ninth filter cavity of the fourth filter branch are capacitively cross-coupled to form a capacitive cross-coupling zero point;

and the seventh filtering cavity and the ninth filtering cavity of the fourth filtering branch are inductively cross-coupled to form an inductive cross-coupling zero point.

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