CN113054352A - Communication device and filter thereof - Google Patents

Abstract

The application discloses a communication device and a filter thereof. The filter includes: a housing having a length direction and a width direction; at least one emission filtering branch, which is arranged on the first side of the shell and consists of six emission filtering cavities coupled in sequence, wherein the six emission filtering cavities further form a capacitive coupling zero point, so that the bandwidth of the emission filtering branch is within the range of 3430Mhz-3488 Mhz. By the mode, the complexity of a product can be reduced, and the stability of the filter can be improved; can adopt the mould to produce, improve and generate efficiency, do benefit to miniaturized design.

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 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 accurately control its upper and lower limit frequencies. And should also consider maintaining high isolation between the passbands of the channels if both transmit and receive channels are present.

The inventor of the application finds that the existing filter is provided with capacitive cross coupling and inductive cross coupling at the same time in long-term research and development work, and the product complexity is high due to the fact that materials of the capacitive cross coupling are different from materials of the inductive cross coupling, and the types of the materials needed by the filter are multiple.

Disclosure of Invention

In order to solve the above problems of the prior art filter, the present application provides a communication device and a filter thereof.

To solve the above problem, an embodiment of the present application provides a filter, including:

a housing having a length direction and a width direction;

at least one emission filtering branch, which is arranged on the first side of the shell and consists of six emission filtering cavities coupled in sequence, wherein the six emission filtering cavities further form a capacitive coupling zero point, so that the bandwidth of the emission filtering branch is within the range of 3430Mhz-3488 Mhz.

In order to solve the above problem, an embodiment of the present application provides a communication device, where the communication device includes the above filter and a communication base station, and the communication base station transmits a radio frequency signal through the filter.

Compared with the prior art, the filter of this application includes: a housing having a length direction and a width direction; at least one emission filtering branch, which is arranged on the first side of the shell and consists of six emission filtering cavities coupled in sequence, wherein the six emission filtering cavities further form a capacitive coupling zero point, so that the bandwidth of the emission filtering branch is within the range of 3430Mhz-3488 Mhz; because the filter is only provided with the capacitive cross coupling zero, zero suppression is realized, and the debugging index is convenient; in addition, the material types are reduced, the product complexity is reduced, and the stability of the filter is improved; in addition, the filter is simple in structure, can be produced by adopting a die, improves the generation efficiency and is beneficial to miniaturization design.

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 a first embodiment of a filter according to the present application;

fig. 2 is a schematic diagram of a topology of the first transmit filter branch of fig. 1;

FIG. 3 is a diagram showing simulation results of the filter of FIG. 1;

FIG. 4 is a schematic diagram of the structure of a second embodiment of the filter of the present application;

fig. 5 is a schematic diagram of the topology of the second transmit filter branch of fig. 4;

FIG. 6 is a schematic diagram of the structure of a second embodiment of the filter of the present application;

fig. 7 is a schematic diagram of the topology of the third transmit filter branch of fig. 6;

fig. 8 is a schematic diagram of the topology of the fourth transmit filter branch of fig. 6;

fig. 9 is a schematic structural diagram of an embodiment of the communication device of 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 apparatus 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 apparatus.

The present application provides a filter of a first embodiment, as shown in fig. 1, fig. 1 is a schematic structural diagram of the first embodiment of the filter of the present application. The filter 10 of the present embodiment includes a housing 11 and at least one transmitting filter branch 12, where the housing 11 may be a bottom wall of a filter cavity (not shown) of the filter 10, and the filter cavity of the filter 10 may further include a side wall disposed on the housing 11 and a cover disposed on the side wall.

The housing 11 has a length direction L and a width direction D, and the length direction L of the housing 11 is perpendicular to the width direction D of the housing 11. The emission filter branch 12 includes six emission filter cavities 121 disposed on the first side 111 of the housing 11 and coupled in sequence, and the six emission filter cavities 121 further form a capacitive cross-coupling zero 122.

The at least one emission filtering branch 12 of this embodiment includes one emission filtering branch 12, that is, a first emission filtering branch 12, the first emission filtering branch 12 is composed of six first emission filtering cavities 121 coupled in sequence, and the six first emission filtering cavities 121 are divided into three rows arranged along the width direction D.

Specifically, the sixth first emission filter cavity a6 and the fifth first emission filter cavity a5 are in a row and are sequentially arranged along the length direction L; the third first emission filter cavity A3 and the fourth first emission filter cavity A4 are in a row and are sequentially arranged along the length direction L; the first and second first transmission filter cavities a1 and a2 are aligned in a row and are sequentially arranged along the length direction L, so that the six first transmission filter cavities 121 are divided into three rows arranged along the length direction L. Because the six first emission filter cavities 121 of the filter 10 are arranged in sequence, the space of the filter cavities can be fully utilized, the cavity volume of the filter 10 is reduced, and the debugging and the production cost are convenient to achieve.

Wherein the third first emission filter cavity A3 is further disposed adjacent to the sixth first emission filter cavity a6 and the first emission filter cavity a 1; the projection of the center of the third first emission filter cavity A3 in the width direction D is located between the center of the sixth first emission filter cavity a6 and the projection of the center of the first emission filter cavity a1 in the width direction D; the projection of the center of the first emission filter cavity a1 in the length direction L is located between the center of the sixth first emission filter cavity a6 and the projection of the center of the third first emission filter cavity A3 in the length direction L.

The third first transmit filter cavity A3 is capacitively cross-coupled with the fifth first transmit filter cavity a5 to form a first capacitive coupling null 122. Specifically, a window (not shown) may be disposed between the third first emission filter cavity A3 and the fifth first emission filter cavity a5, and a capacitive fly bar (not shown) may be disposed between the third first emission filter cavity A3 and the fifth first emission filter cavity a5, so that the third first emission filter cavity A3 and the fifth first emission filter cavity a5 are capacitively cross-coupled, which is equivalent to the capacitor c1 shown in fig. 2.

Wherein the size of the first emission filter cavity a1, the size of the second first emission filter cavity a2, the size of the third first emission filter cavity A3, the size of the fourth first emission filter cavity a4, the size of the fifth first emission filter cavity a5 and the size of the sixth first emission filter cavity a6 may be the same.

The third first emission filter cavity A3 and the fifth first emission filter cavity a5 of the present embodiment are capacitively cross-coupled to form the first capacitive coupling zero 122, so as to implement zero suppression and facilitate index debugging. Compared with the filter in the prior art which is provided with capacitive cross coupling and inductive cross coupling at the same time, the filter 10 of the embodiment is only provided with the first capacitive coupling zero point 122, so that the material types are reduced, the product complexity is reduced, the stability of the filter is improved, and the production cost is reduced; in addition, the filter 10 has a simple structure, can be produced by using a mold, improves the production efficiency, and is beneficial to miniaturization design.

Optionally, the first side 111 of the housing 11 is further provided with a first input port (not shown) and a first output port (not shown), the first emission filter cavity a1 is connected with the first input port, and the sixth first emission filter cavity a6 is connected with the first output port.

The bandwidth of the transmitting filter branch 12 of the present application is in the range of 3430Mhz-3488 Mhz. Specifically, the coupling bandwidth between the first input port and the first emission filter cavity a1 ranges from 64Mhz to 68 Mhz; the coupling bandwidth between the first emission filter cavity a1 and the second first emission filter cavity a2 ranges from 47Mhz to 51 Mhz; the coupling bandwidth between the second first emission filter cavity a2 and the third first emission filter cavity A3 ranges from 31Mhz to 35 Mhz; the coupling bandwidth between the third first emission filter cavity A3 and the fourth first emission filter cavity a4 ranges from 29Mhz to 33 Mhz; the coupling bandwidth between the third first emission filter cavity A3 and the fifth first emission filter cavity a5 is in the range of (-7) Mhz- (-3) Mhz; the coupling bandwidth between the fourth first emission filter cavity a4 and the fifth first emission filter cavity a5 ranges from 31Mhz to 35 Mhz; the coupling bandwidth between the fifth first emission filter cavity a5 and the sixth first emission filter cavity a6 ranges from 47Mhz to 51 Mhz; the coupling bandwidth between the sixth first transmit filter cavity a6 and the first output port is in the range of 64Mhz-58 Mhz.

Therefore, the resonant frequencies of the first to sixth first transmission filter cavities a1 to a6 are in the following ranges in order: 3457Mhz-3461Mhz, 3452Mhz-3456Mhz, 3457Mhz-3461 Mhz.

As shown in fig. 3, fig. 3 is a diagram showing simulation results of the filter of fig. 1. Experimental tests have shown that the bandwidth of the filter 10 of the present application is in the range of 3430Mhz-3488Mhz, as shown by the band curve 20 in fig. 3, where the emission bandwidth rejection satisfies: 3346MHz >75 dB; 3370 MHz-3390 MHz >60-3 x (f-3370) dB; 3556.8 MHz-3596.8 MHz >20 dB; 3560 MHz-3600 MHz >23 dB; 3586 MHz-3606 MHz >13 dB; 3600 MHz-4200 MHz >48 dB; 3618.24 MHz-3658.24 MHz >55 dB; 3620 MHz-12750 MHz >35 dB; 3625 MHz-3800 MHz >78 dB; 3800 MHz-7750 MHz >78 dB; 3864 MHz-3904 MHz >85 dB; 12750 MHz-18000 MHz >20 dB. In addition, the bandwidth of the first capacitive cross-coupling zero 122 is 3370MHz, and the bandwidth rejection is greater than 60dB, so that the out-of-band rejection performance of the filter 10 can be improved.

The present application provides a filter of the second embodiment, which is described on the basis of the filter 10 disclosed in the first embodiment. As shown in fig. 4, the filter 10 of the present embodiment further includes a second transmitting filter branch 123, and the second transmitting filter branch 123 is composed of six second transmitting filter cavities 124 coupled in sequence. Therein, the six first emission filter cavities 121 and the six second emission filter cavities 124 are divided into three rows arranged in the width direction D.

Specifically, the sixth first emission filter cavity a6, the fifth first emission filter cavity a5, the sixth second emission filter cavity B6 and the fifth second emission filter cavity B5 are in a row and are sequentially arranged along the length direction L; the third first emission filter cavity A3, the fourth first emission filter cavity A4, the third second emission filter cavity B3 and the fourth second emission filter cavity B4 are in a row and are sequentially arranged along the length direction L; the first emission filter cavity A1, the second first emission filter cavity A2, the first second emission filter cavity B1 and the second emission filter cavity B2 are in a row and are sequentially arranged along the length direction L; the third second emission filter cavity B3 is further disposed adjacent to the sixth second emission filter cavity B6 and the first second emission filter cavity B1.

Wherein the third second emission filter cavity B3 is capacitively cross-coupled with the fifth second emission filter cavity B5 to form the second capacitive coupling zero 125. Specifically, a window (not shown) may be disposed between the third second emission filter cavity B3 and the fifth second emission filter cavity B5, and a capacitive fly rod (not shown) may be disposed between the third second emission filter cavity B3 and the fifth second emission filter cavity B5, so that the third second emission filter cavity B3 and the fifth second emission filter cavity B5 are capacitively cross-coupled, which is equivalent to the capacitor c2 shown in fig. 5.

Optionally, the first side 111 of the housing 11 is further provided with a second input port (not shown) and a second output port (not shown), the first and second transmitting filter cavities B1 are connected to the second input port, and the sixth transmitting filter cavity B6 is connected to the second output port.

The bandwidth of the second transmit filter branch 123 of the present application is in the range of 3430Mhz-3488 Mhz. Specifically, the coupling bandwidth between the second input port and the first second emission filter cavity B1 is in the range of 64Mhz-68 Mhz; the coupling bandwidth between the first second emission filter cavity B1 and the second emission filter cavity B2 ranges from 47Mhz to 51 Mhz; the coupling bandwidth between the second emission filter cavity B2 and the third second emission filter cavity B3 ranges from 31Mhz to 35 Mhz; the coupling bandwidth between the third second emission filter cavity B3 and the fourth second emission filter cavity B4 ranges from 29Mhz to 33 Mhz; the coupling bandwidth between the third second emission filter cavity B3 and the fifth second emission filter cavity B5 is in the range of (-7) Mhz- (-3) Mhz; the coupling bandwidth between the fourth second emission filter cavity B4 and the fifth second emission filter cavity B5 ranges from 31Mhz to 35 Mhz; the coupling bandwidth between the fifth second emission filter cavity B5 and the sixth second emission filter cavity B6 ranges from 47Mhz to 51 Mhz; the coupling bandwidth between the sixth second emission filter cavity B6 and the second output port ranges from 64Mhz to 58 Mhz.

Therefore, the resonant frequencies of the first second emission filter cavity B1 to the sixth second emission filter cavity B6 are sequentially located in the following ranges: 3457Mhz-3461Mhz, 3452Mhz-3456Mhz, 3457Mhz-3461 Mhz. The simulation result of the second transmitting and filtering branch 123 is the same as the frequency band curve 20 shown in fig. 3, and is not described herein again.

The cavities of the first transmitting filter branch 12 and the second transmitting filter branch 123 of the present embodiment are arranged in sequence, so that the space of the filter 10 can be fully utilized, the size of the filter 10 is reduced, and the production cost is reduced. In addition, the filter 10 of the present embodiment includes two transmitting and filtering branches, which can improve the isolation between the radio frequency signals and improve the out-of-band rejection and other performances of the filter 10.

The present application provides a filter of a third embodiment, which is described on the basis of the filter 10 disclosed in the second embodiment. As shown in fig. 6, the filter 10 of this embodiment further includes a third transmitting filter branch 126 and a fourth transmitting filter branch 129, where the third transmitting filter branch 126 is composed of six third transmitting filter cavities 127 coupled in sequence, and the fourth transmitting filter branch 129 is composed of six fourth transmitting filter cavities 130 coupled in sequence. Wherein, the six first emission filter cavities 121, the six second emission filter cavities 124, the six third emission filter cavities 127 and the six fourth emission filter cavities 130 are divided into three rows arranged along the width direction D.

Specifically, a sixth first emission filter cavity a6, a fifth first emission filter cavity a5, a sixth second emission filter cavity B6, a fifth second emission filter cavity B5, a sixth third emission filter cavity C6, a fifth third emission filter cavity C5, a sixth fourth emission filter cavity D6, and a fifth fourth emission filter cavity D5 are in a row and are sequentially arranged along the length direction L; the third first emission filter cavity A3, the fourth first emission filter cavity A4, the third second emission filter cavity B3, the fourth second emission filter cavity B4, the third emission filter cavity C3, the fourth third emission filter cavity C4, the third fourth emission filter cavity D3 and the fourth emission filter cavity D4 are in a row and are sequentially arranged along the length direction L; the first emission filter cavity A1, the second first emission filter cavity A2, the first second emission filter cavity B1, the second emission filter cavity B2, the second third emission filter cavity C2, the first third emission filter cavity C1, the second fourth emission filter cavity D2 and the first fourth emission filter cavity D1 are in a column and are sequentially arranged along the length direction L.

Wherein the third emission filter cavity C3 is further disposed adjacent to the sixth emission filter cavity C6 and the second emission filter cavity C2; the third fourth emission filter cavity D3 is further disposed adjacent to the sixth emission filter cavity D6 and the second fourth emission filter cavity D2.

Wherein the third emission filter cavity C3 is capacitively cross-coupled with the fifth emission filter cavity C5 to form a third capacitive coupling zero 128, which is equivalent to the capacitor C3 shown in fig. 7. The third fourth emission filter cavity D3 is capacitively cross-coupled with the fifth emission filter cavity D5 to form a fourth capacitive coupling zero 131, which is equivalent to the capacitor c4 shown in fig. 8.

Optionally, the first side 111 of the housing 11 is further provided with a third input port, a fourth input port, a third output port and a fourth output port, the first third emission filter cavity C1 is connected to the third input port, the sixth third emission filter cavity C6 is connected to the third output port, the first fourth emission filter cavity D1 is connected to the fourth input port, and the sixth fourth emission filter cavity D6 is connected to the fourth output port.

The bandwidth of the third transmit filter branch 126 is in the range of 3430Mhz-3488 Mhz. Specifically, the coupling bandwidth between the third input port and the first third emission filter cavity C1 is in the range of 64Mhz-68 Mhz; the coupling bandwidth between the first third emission filter cavity C1 and the second third emission filter cavity C2 ranges from 47Mhz to 51 Mhz; the coupling bandwidth between the second third emission filter cavity C2 and the third emission filter cavity C3 ranges from 31Mhz to 35 Mhz; the coupling bandwidth between the third emission filter cavity C3 and the fourth emission filter cavity C4 ranges from 29Mhz to 33 Mhz; the coupling bandwidth between the third emission filter cavity C3 and the fifth emission filter cavity C5 is in the range of (-7) Mhz- (-3) Mhz; the coupling bandwidth between the fourth third emission filter cavity C4 and the fifth third emission filter cavity C5 ranges from 31Mhz to 35 Mhz; the coupling bandwidth between the fifth third emission filter cavity C5 and the sixth third emission filter cavity C6 ranges from 47Mhz to 51 Mhz; the coupling bandwidth between the sixth third emission filter cavity C6 and the third output port ranges from 64Mhz to 58 Mhz.

Therefore, the resonant frequencies of the first third emission filter cavity C1 to the sixth third emission filter cavity C6 are sequentially located in the following ranges: 3457Mhz-3461Mhz, 3452Mhz-3456Mhz, 3457Mhz-3461 Mhz.

The bandwidth of the fourth transmit filter branch 129 is in the range of 3430Mhz-3488 Mhz. Specifically, the coupling bandwidth between the fourth input port and the first fourth emission filter cavity D1 is in the range of 64Mhz-68 Mhz; the coupling bandwidth between the first fourth emission filter cavity D1 and the second fourth emission filter cavity D2 ranges from 47Mhz to 51 Mhz; the coupling bandwidth between the second fourth emission filter cavity D2 and the third fourth emission filter cavity D3 ranges from 31Mhz to 35 Mhz; the coupling bandwidth between the third fourth emission filter cavity D3 and the fourth emission filter cavity D4 ranges from 29Mhz to 33 Mhz; the coupling bandwidth between the third fourth emission filter cavity D3 and the fifth fourth emission filter cavity D5 is in the range of (-7) Mhz- (-3) Mhz; the coupling bandwidth between the fourth emission filter cavity D4 and the fifth emission filter cavity D5 ranges from 31Mhz to 35 Mhz; the coupling bandwidth between the fifth and sixth emission filter cavities D5 and D6 ranges from 47Mhz to 51 Mhz; the coupling bandwidth between the sixth fourth emission filter cavity D6 and the fourth output port ranges from 64Mhz to 58 Mhz.

Therefore, the resonant frequencies of the first fourth emission filter cavity D1 to the sixth fourth emission filter cavity D6 are sequentially located in the following ranges: 3457Mhz-3461Mhz, 3452Mhz-3456Mhz, 3457Mhz-3461 Mhz.

The simulation results of the third transmitting filter branch 126 and the fourth transmitting filter branch 129 are the same as the frequency band curve 20 shown in fig. 3, and are not described herein again.

The filter 10 of this embodiment can be provided with four emission filtering branches, and the cavities of the first emission filtering branch 12, the second emission filtering branch 123, the third emission filtering branch 126, and the fourth emission filtering branch 129 are arranged in sequence, so that the space of the filter 10 can be fully utilized, the size of the filter 10 is reduced, and the production cost is reduced.

The present application further provides a communication device, as shown in fig. 9, fig. 9 is a schematic structural diagram of an embodiment of the communication device of the present application. The communication device of this embodiment includes a communication base station 91 and a filter 92, where the filter 92 is disposed at a radio frequency front end of the communication base station 91, so that the communication base station 91 transmits and receives radio frequency signals through the filter 92, and the filter 92 may be the above-mentioned filter 10, which is not described herein again.

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 (10)

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

a housing having a length direction and a width direction;

at least one emission filtering branch, which is arranged on the first side of the shell and consists of six emission filtering cavities coupled in sequence, wherein the six emission filtering cavities further form a capacitive coupling zero point, so that the bandwidth of the emission filtering branch is within the range of 3430Mhz-3488 Mhz.

2. The filter according to claim 1, wherein the at least one emission filtering branch comprises a first emission filtering branch, the first emission filtering branch is composed of six first emission filtering cavities coupled in sequence, and the six first emission filtering cavities are divided into three rows arranged along the width direction;

the sixth first emission filter cavity and the fifth first emission filter cavity are in a row and are sequentially arranged along the length direction;

the third first emission filter cavity and the fourth first emission filter cavity are in a row and are sequentially arranged along the length direction;

the first emission filter cavity and the second emission filter cavity are in a row and are sequentially arranged along the length direction;

the third first emission filter cavity is further adjacent to the sixth first emission filter cavity and the first emission filter cavity, the third projection of the center of the first emission filter cavity in the width direction is located the sixth projection of the center of the first emission filter cavity and the first projection of the center of the first emission filter cavity in the width direction are located between the projections in the width direction, the first projection of the center of the first emission filter cavity in the length direction is located the sixth projection of the center of the first emission filter cavity and the third projection of the center of the first emission filter cavity in the length direction are located between the projections in the length direction.

3. The filter of claim 2, wherein a third of the first transmit filter cavities is capacitively cross-coupled with a fifth of the first transmit filter cavities to form a first capacitive coupling zero.

4. The filter according to claim 2, wherein the at least one transmit filter branch further includes a second transmit filter branch, the second transmit filter branch is composed of six second transmit filter cavities coupled in sequence, and the six first transmit filter cavities and the six second transmit filter cavities are divided into three rows arranged along the width direction;

the sixth first emission filter cavity, the fifth first emission filter cavity, the sixth second emission filter cavity and the fifth second emission filter cavity are in a row and are sequentially arranged along the length direction;

the third first emission filter cavity, the fourth first emission filter cavity, the third second emission filter cavity and the fourth second emission filter cavity are in a row and are sequentially arranged along the length direction;

the first emission filter cavity, the second first emission filter cavity, the first second emission filter cavity and the second emission filter cavity are in a row and are sequentially arranged along the length direction;

the third second emission filter cavity is further arranged adjacent to the sixth second emission filter cavity and the first second emission filter cavity.

5. The filter of claim 4 wherein a third of said second transmit filter cavities is capacitively cross-coupled to a fifth of said second transmit filter cavities to form a second capacitive coupling zero.

6. The filter according to claim 4, wherein the at least one transmitting filter branch further includes a third transmitting filter branch and a fourth transmitting filter branch, the third transmitting filter branch is composed of six third transmitting filter cavities coupled in sequence, and the fourth transmitting filter branch is composed of six fourth transmitting filter cavities coupled in sequence.

7. The filter of claim 6, wherein a sixth of the first emission filter cavity, a fifth of the first emission filter cavity, a sixth of the second emission filter cavity, a fifth of the second emission filter cavity, a sixth of the third emission filter cavity, a fifth of the third emission filter cavity, a sixth of the fourth emission filter cavity, and a fifth of the fourth emission filter cavity are in a row and are arranged in sequence along the length direction;

the third first emission filter cavity, the fourth first emission filter cavity, the third second emission filter cavity, the fourth second emission filter cavity, the third emission filter cavity, the fourth third emission filter cavity, the third fourth emission filter cavity and the fourth emission filter cavity are in a row and are sequentially arranged along the length direction;

the first emission filter cavity, the second emission filter cavity, the third emission filter cavity, the first emission filter cavity, the second emission filter cavity, the fourth emission filter cavity and the first emission filter cavity are in a row and are sequentially arranged along the length direction.

8. The filter of claim 7, wherein a third of the third emission filter cavities is further disposed adjacent to a sixth of the third emission filter cavities and a second of the third emission filter cavities;

the third emission filter cavity is further adjacent to the sixth emission filter cavity and the second emission filter cavity.

9. The filter of claim 8, wherein a third of the third transmit filter cavities is capacitively cross-coupled with a fifth of the third transmit filter cavities to form a third capacitive coupling zero;

a third of said fourth transmit filter cavities is capacitively cross-coupled with a fifth of said fourth transmit filter cavities to form a fourth capacitive coupling zero.

10. A communication device, characterized in that it comprises a filter according to any one of claims 1-9 and a communication base station, which transmits radio frequency signals through the filter.

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