CN113036366A

CN113036366A - Communication system and filter thereof

Info

Publication number: CN113036366A
Application number: CN201911361400.4A
Authority: CN
Inventors: 温世议; 李华; 蔡永宏; 王磊
Original assignee: Shenzhen Tatfook Technology Co Ltd
Current assignee: Shenzhen Tatfook Technology Co Ltd
Priority date: 2019-12-25
Filing date: 2019-12-25
Publication date: 2021-06-25

Abstract

The application discloses a communication system and a filter thereof. The filter includes: a housing having a first direction and a second direction perpendicular to each other; the first common cavity and the second common cavity are arranged on one side of the shell at intervals; the first filtering branch circuit is respectively coupled with the first common cavity and the second common cavity and consists of nine filtering cavities which are sequentially coupled; and the second filtering branch circuit is respectively coupled with the first common cavity and the second common cavity and consists of eight filtering cavities which are sequentially coupled. By the mode, the isolation between the two filtering branches is high, the product complexity can be reduced, and the stability of the filter is improved.

Description

Communication system and filter thereof

Technical Field

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

Background

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

The inventor of this application discovers in long-term research and development work, and for reducing the volume of wave filter, the wave filter is provided with the filtering branch road of two sets of or more than two sets of different frequencies usually, but every filtering branch road that has now all need independently to be provided with the tap, and the quantity of tapping is too much, leads to required welding point also more, is unfavorable for reducing the volume of wave filter, influences the stability of wave filter.

Disclosure of Invention

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

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

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

the first common cavity and the second common cavity are arranged on one side of the shell at intervals;

the first filtering branch circuit is respectively coupled with the first common cavity and the second common cavity and consists of nine filtering cavities which are sequentially coupled;

and the second filtering branch circuit is respectively coupled with the first common cavity and the second common cavity and consists of eight filtering cavities which are sequentially coupled.

Wherein the first common cavity, the second common cavity, the nine filter cavities of the first filter branch and the eight filter cavities of the second filter branch are divided into five columns arranged along the first direction;

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

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

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

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

and the seventh filtering cavity, the eighth filtering cavity, the second common cavity and the ninth filtering cavity of the first filtering branch are in a row and are sequentially arranged along the second direction.

The first common cavity is respectively adjacent to the first filter cavity of the first filter branch and the first filter cavity of the second filter branch;

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

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

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

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

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

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

and the ninth filter of the first filtering branch is respectively arranged adjacent to the seventh filter of the first filtering branch and the second common cavity.

The filter further comprises a third filtering branch, the third filtering branch is coupled with the first common cavity and consists of ten filtering cavities which are sequentially coupled, and the ten filtering cavities of the third filtering branch further form a cross-coupling zero point.

Wherein the first common cavity, the second common cavity, the nine filter cavities of the first filter branch, the eight filter cavities of the second filter branch, and the ten filter cavities of the third filter branch are divided into five columns arranged along the first direction.

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

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

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

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

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

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

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

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

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

and the tenth filtering cavity of the third filtering branch is respectively adjacent to the eighth filtering cavity, the ninth filtering cavity of the third filtering branch and the seventh filtering cavity of the second filtering branch.

And the fourth filter cavity and the sixth filter cavity of the third filter branch are in cross coupling to form the cross coupling zero point.

And the distances between the centers of any two adjacent filter cavities in the first filter branch, the second filter branch and the third filter branch are equal.

In order to solve the above problem, an embodiment of the present application provides a communication system, where the communication system includes a terminal and a base station, the base station includes a base station antenna and a radio frequency unit, the radio frequency unit includes the filter as described above, and the filter is used for filtering a radio frequency signal.

Compared with the prior art, the filter of this application includes: a housing having a first direction and a second direction perpendicular to each other; the first common cavity and the second common cavity are arranged on one side of the shell at intervals; the first filtering branch circuit is respectively coupled with the first common cavity and the second common cavity and consists of nine filtering cavities which are sequentially coupled; the second filtering branch circuit is respectively coupled with the first common cavity and the second common cavity and consists of eight filtering cavities which are sequentially coupled; this application is because the wave filter is provided with first common chamber and second common chamber, can dwindle the volume of wave filter, reduces the quantity of taking a percentage, reduces the welding point.

Drawings

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

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

FIG. 2 is a schematic diagram of the topology of the first filtering branch of FIG. 1;

FIG. 3 is a schematic diagram of the topology of the second filtering branch of FIG. 1;

FIG. 4 is a schematic structural diagram of another embodiment of a filter cavity of the present application;

FIG. 5 is a schematic diagram of the topology of the third filtering branch of FIG. 4;

FIG. 6 is a diagram showing simulation results of the filter of FIG. 1;

FIG. 7 is a diagram illustrating simulation results of a third filtering branch of the filter of FIG. 4;

fig. 8 is a schematic structural diagram of an embodiment of the communication system 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, as shown in fig. 1, fig. 1 is a schematic structural diagram of an embodiment of the filter of the present application. The filter 10 of the present embodiment includes a housing 11, a first common cavity 12, a second common cavity 13, a first filtering branch 14 and a second filtering branch 15; the first filtering branch 14 and the second filtering branch 15 may be a receiving filtering branch and a transmitting filtering branch, respectively, or may be both a receiving filtering branch or a transmitting filtering branch. The first common cavity 12 and the second common cavity 13 are spaced apart from each other on one side of the housing 11, 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 first direction L and a second direction D, and the first direction L of the housing 11 is perpendicular to the second direction D of the housing 11.

The first filtering branch 14 is coupled to the first common cavity 12 and the second common cavity 13, and is composed of nine filtering cavities coupled in sequence. The second filtering branch 15 is respectively coupled with the first common cavity 12 and the second common cavity 13, and is composed of eight filtering cavities coupled in sequence.

In this embodiment, the first filtering branch 14 and the second filtering branch 15 are connected between the first common cavity 12 and the second common cavity 13 to implement signal transceiving, and the number of taps can be reduced by setting the common cavity, so as to reduce the number of welding points, further reduce the size of the filter 10 and improve the out-of-band rejection performance of the filter 10.

Further, the first common cavity 12, the second common cavity 13, the nine filter cavities of the first filter branch 14 and the eight filter cavities of the second filter branch 15 are divided into five columns arranged along the first direction L.

Wherein, the first common cavity 12, the first filtering cavity a1 and the second filtering cavity a2 of the first filtering branch 14 are in a row and are sequentially arranged along the second direction D; the second filtering cavity B2, the first filtering cavity B1, the fourth filtering cavity a4 and the third filtering cavity A3 of the second filtering branch 15 are in a row and are sequentially arranged along the second direction D; the third filtering cavity B3, the fourth filtering cavity B4 of the second filtering branch 15, the fifth filtering cavity a5 and the sixth filtering cavity a6 of the first filtering branch 14 are in a row and are sequentially arranged along the second direction D; the sixth filtering cavity B6, the fifth filtering cavity B5 of the second filtering branch 15, the eighth filtering cavity a8 and the seventh filtering cavity a7 of the first filtering branch 14 are in a row and are sequentially arranged along the second direction D; the seventh filtering cavity B7, the eighth filtering cavity B8, the second common cavity 13 of the second filtering branch 15 and the ninth filtering cavity a9 of the first filtering branch 14 are in a row and are sequentially arranged along the second direction.

In particular, the first common cavity 12 is respectively arranged adjacent to the first filtering cavity a1 of the first filtering branch 14 and the first filtering cavity B1 of the second filtering branch 15; the fourth filtering cavity a4 of the first filtering branch 14 is respectively adjacent to the first filtering cavity a1 and the third filtering cavity A3 of the first filtering branch 14, the first filtering cavity B1 of the second filtering branch 15 and the fifth filtering cavity a5 of the first filtering branch 14; the fourth filtering cavity B4 of the second filtering branch 15 is respectively adjacent to the first filtering cavity B1 and the third filtering cavity B3 of the second filtering branch 15, the fifth filtering cavity a5 of the first filtering branch 14 and the fifth filtering cavity B5 of the second filtering branch 15; the sixth filtering cavity a6 of the first filtering branch 14 is respectively adjacent to the third filtering cavity A3, the fifth filtering cavity a5 and the seventh filtering cavity a7 of the first filtering branch 14; the sixth filtering cavity B6 of the second filtering branch 15 is respectively adjacent to the third filtering cavity B3, the fifth filtering cavity B5, the seventh filtering cavity B7 and the eighth filtering cavity B8 of the second filtering branch 15; the eighth filtering cavity B8 of the second filtering branch 15 is respectively adjacent to the fifth filtering cavity B5, the sixth filtering cavity B6, the seventh filtering cavity B7 and the second common cavity 13 of the second filtering branch 15; the eighth filtering cavity A8 of the first filtering branch 14 is respectively adjacent to the fifth filtering cavity a5, the seventh filtering cavity a7, the ninth filtering cavity a9 of the first filtering branch 14, the fifth filtering cavity B5 of the second filtering branch 15 and the second common cavity 13; the ninth filter a9 of the first filtering branch 14 is arranged adjacent to the seventh filter a7 and the second common cavity 13 of the first filtering branch 14, respectively.

Wherein, the nine filtering cavities of first common cavity 12, second common cavity 13, first filtering branch 14 and the eight filtering cavities of second filtering branch 15 are regularly arranged, can save the space in the casing 11, are favorable to reducing the volume of wave filter 10, improve the stability of wave filter 10. Further, the sizes of the filter cavities in the nine filter cavities of the first filter branch 14 and the eight filter cavities of the second filter branch 15 are the same, so that the filter cavities in the housing 11 can be arranged in an equidistant distribution manner, the distances between the centers of any two adjacent filter cavities are equal, the arrangement is tight, the layout and the debugging are facilitated, and the consistency of the filter 10 is improved.

That is, on the basis of regular arrangement of resonant cavities in the filter, the required pass band of the filter can be obtained by combining the resonant frequencies of the corresponding resonant cavities according to the actual design requirement; meanwhile, the resonant cavity has good consistency, so that the layout and debugging are convenient, and the consistency of the filter 10 is improved.

As shown in fig. 2 and 3, the first filtering branch 14 and the second filtering branch 15 are both pure window structures, and the window coupling consistency between adjacent filtering cavities is good, the cost is low, the material types are few, the complexity of the filter 10 can be reduced, and the stability of the filter 10 is improved.

In this embodiment, the first filtering branch 14 and the second filtering branch 15 are connected between the first common cavity 12 and the second common cavity 13 to implement signal transceiving, and the number of taps can be reduced by setting the common cavity, so as to reduce the number of welding points, further reduce the size of the filter 10 and improve the out-of-band rejection performance of the filter 10; nine filtering cavities of the first common cavity 12, the second common cavity 13 and the first filtering branch 14 and eight filtering cavities of the second filtering branch 15 in the filter 10 are regularly arranged, so that the space in the shell 11 can be saved, the size of the filter 10 is favorably reduced, and the stability of the filter 10 is improved.

Referring to fig. 4, fig. 4 is a schematic structural diagram of another embodiment of a filter cavity according to the present application. The filter 10 of the present embodiment further includes a third filtering branch 16 on the basis of the embodiment shown in fig. 1.

A third filter branch 16 is arranged on one side of the housing 11 and adjacent to the second filter branch 15. The third filtering branch 16 is coupled to the first common cavity 12 and is composed of ten filtering cavities coupled in sequence, wherein the ten filtering cavities of the third filtering branch 16 further form a cross-coupling zero 161, which can realize zero suppression.

In the present embodiment, the third filtering branch 16 is connected to the first common cavity 12 to implement signal transceiving, so as to reduce the size of the filter 10 and improve the out-of-band rejection performance of the filter 10.

Further, the first common cavity 12, the second common cavity 13, the nine filter cavities of the first filter branch 14, the eight filter cavities of the second filter branch 15 and the ten filter cavities of the third filter branch 16 are divided into five columns arranged along the first direction L.

The third filtering cavity C3, the second filtering cavity C2, the first filtering cavity C1, the first common cavity 12, the first filtering cavity a1 and the second filtering cavity a2 of the first filtering branch 14 of the third filtering branch 16 are in a row and are sequentially arranged along the second direction D; the fourth filtering cavity C4, the fifth filtering cavity C5 of the third filtering branch 16, the second filtering cavity B2 of the second filtering branch 15, the first filtering cavity B1, the fourth filtering cavity a4 and the third filtering cavity A3 of the first filtering branch 14 are in a row and are sequentially arranged along the second direction D; the seventh filtering cavity C7, the sixth filtering cavity C6 of the third filtering branch 16, the third filtering cavity B3 of the second filtering branch 15, the fourth filtering cavity B4, the fifth filtering cavity a5 and the sixth filtering cavity a6 of the first filtering branch 14 are in a row and are sequentially arranged along the second direction D; the eighth filtering cavity C8, the ninth filtering cavity C9 of the third filtering branch 16, the sixth filtering cavity B6, the fifth filtering cavity B5 of the second filtering branch 15, the eighth filtering cavity a8 and the seventh filtering cavity a7 of the first filtering branch 14 are in a row and are sequentially arranged along the second direction D; the tenth filter cavity C10 of the third filter branch 16, the seventh filter cavity B7 of the second filter branch 15, the eighth filter cavity B8, the second common cavity 13, and the ninth filter cavity a9 of the first filter branch 14 are arranged in a row and sequentially along the second direction D.

Specifically, the first filter cavity C1 of the third filter branch 16 is respectively disposed adjacent to the second filter cavity C2 of the third filter branch 16, the second filter cavity B2 of the second filter branch 15, and the first common cavity 12; the fifth filtering cavity C5 of the third filtering branch 16 is respectively adjacent to the second filtering cavity C2, the fourth filtering cavity C4, the sixth filtering cavity C6 of the third filtering branch 16 and the second filtering cavity B2 of the second filtering branch 15; the seventh filtering cavity C7 of the third filtering branch 16 is respectively adjacent to the fourth filtering cavity C4, the sixth filtering cavity C6 and the eighth filtering cavity C8 of the third filtering branch 16; the ninth filtering cavity C9 of the third filtering branch 16 is respectively adjacent to the sixth filtering cavity C6, the eighth filtering cavity C8, the tenth filtering cavity C10, the seventh filtering cavity B7 and the sixth filtering cavity B6 of the second filtering branch 15; the tenth filter cavity C10 of the third filter branch 16 is respectively disposed adjacent to the eighth filter cavity C8, the ninth filter cavity C9 of the third filter branch 16 and the seventh filter cavity B7 of the second filter branch 15.

Wherein, nine filtering cavities of first common cavity 12, second common cavity 13, first filtering branch 14, eight filtering cavities of second filtering branch 15 and ten filtering cavities of third filtering branch 16 are regularly arranged, can save the space in the casing 11, are favorable to reducing the volume of wave filter 10, improve the stability of wave filter 10. Further, the sizes of the nine filter cavities of the first common cavity 12 and the first common cavity 13 and the nine filter cavities of the first filter branch 14, the eight filter cavities of the second filter branch 15 and the ten filter cavities of the third filter branch 16 are the same, so that the filter cavities in the shell 11 can be arranged in an equidistant manner, the distances between the centers of any two adjacent filter cavities are equal, the arrangement is tight, the layout and debugging are facilitated, and the consistency of the filter 10 is improved.

As shown in fig. 5, the fourth filter cavity C4 of the third filter branch 16 is cross-coupled with the sixth filter cavity C6 to form a cross-coupling zero 161. The zero point suppression can be realized by setting the cross coupling zero point 161, so that the debugging index is convenient, and the design requirement is met.

The coupling zero is also referred to as a transmission zero. The transmission zero is the transmission function of the filter 10 equal to zero, that is, the electromagnetic energy 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 this embodiment, the third filtering branch 16 is connected to the first common cavity 12 to implement signal transceiving, so as to reduce the size of the filter 10 and improve the out-of-band rejection performance of the filter 10; the first common cavity 12, the second common cavity 13, the nine filter cavities of the first filter branch 14, the eight filter cavities of the second filter branch 15 and the ten filter cavities of the third filter branch 16 are regularly arranged, so that the space in the shell 11 can be saved, the size of the filter 10 can be reduced, and the stability of the filter 10 can be improved; nine filter cavities of the first filter branch 14, eight filter cavities of the second filter branch 15 and ten filter cavities of the third filter branch 16 of the first common cavity 12, the second common cavity 13 and the third common cavity are all the same in size, so that the filter cavities in the shell 11 can be distributed and arranged at equal intervals, the distances between the centers of any two adjacent filter cavities are equal, the arrangement is tight, the layout and debugging are convenient, and the consistency of the filter 10 is improved; the zero point suppression can be realized by the arrangement of the cross-coupling zero point 161 of the third filtering branch 16, so that the debugging index is convenient, and the design requirement is met.

Optionally, one side of the housing 11 is further provided with a first port (not shown), a second port (not shown) and a third port (not shown), the first common cavity 12 is connected with the first port, the tenth filtering cavity C10 of the third filtering branch 16 is connected with the second port, and the second common cavity 13 is connected with the third port. Wherein the first port, the second port, and the third port may all be taps of the filter 10. The filter 10 is provided with the first common cavity 12 and the second common cavity 13, so that the size of the filter 10 can be reduced, the number of taps can be reduced, and the number of welding points can be reduced.

The bandwidth of the first filtering branch 14 of this embodiment is in the range of 1709Mhz-1781 Mhz. Specifically, the coupling bandwidth between the first port and the first common cavity 12 ranges from 802Mhz to 896 Mhz; the coupling bandwidth between the first common cavity 12 and the first filter cavity a1 of the first filter branch 14 ranges from 242Mhz to 274 Mhz; the coupling bandwidth between the first filter cavity a1 of the first filter branch 14 and the second filter cavity a2 of the first filter branch 14 ranges from 52Mhz to 62 Mhz; the coupling bandwidth between the second filter cavity a2 of the first filter branch 14 and the third filter cavity A3 of the first filter branch 14 ranges from 39Mhz to 48 Mhz; the coupling bandwidth between the third filter cavity A3 of the first filter branch 14 and the fourth filter cavity a4 of the first filter branch 14 ranges from 36Mhz to 45 Mhz; the coupling bandwidth between the fourth filter cavity a4 of the first filter branch 14 and the fifth filter cavity a5 of the first filter branch 14 ranges from 35Mhz to 44 Mhz; the coupling bandwidth between the fifth filter cavity a5 of the first filter branch 14 and the sixth filter cavity a6 of the first filter branch 14 ranges from 35Mhz to 44 Mhz; the coupling bandwidth between the sixth filter cavity a6 of the first filter branch 14 and the seventh filter cavity a7 of the first filter branch 14 ranges from 36Mhz to 45 Mhz; the coupling bandwidth between the seventh filter cavity a7 of the first filter branch 14 and the eighth filter cavity A8 of the first filter branch 14 ranges from 39Mhz to 48 Mhz; the coupling bandwidth between the eighth filter cavity A8 of the first filter branch 14 and the ninth filter cavity a9 of the first filter branch 14 ranges from 56Mhz to 67 Mhz; the coupling bandwidth between the ninth filter cavity a9 of the first filter branch 14 and the second common cavity 13 ranges from 70Mhz to 82 Mhz.

The bandwidth of the second filtering branch 15 of this embodiment is in the range of 2109Mhz-2199 Mhz. In particular, the coupling bandwidth between the first common cavity 12 and the first filter cavity B1 of the second filter branch 15 ranges from 35143Mhz to 39053 Mhz; the coupling bandwidth between the first filter cavity B1 of the second filter branch 15 and the second filter cavity B2 of the second filter branch 15 ranges from 0.62Mhz to 0.74 Mhz; the coupling bandwidth between the second filter cavity B2 of the second filter branch 15 and the third filter cavity B3 of the second filter branch 15 ranges from 29Mhz to 37 Mhz; the coupling bandwidth between the third filter cavity B3 of the second filter branch 15 and the fourth filter cavity B4 of the second filter branch 15 ranges from 34Mhz to 43 Mhz; the coupling bandwidth between the fourth filter cavity B4 of the second filter branch 15 and the fifth filter cavity B5 of the second filter branch 15 ranges from 35Mhz to 44 Mhz; the coupling bandwidth between the fifth filter cavity B5 of the second filter branch 15 and the sixth filter cavity B6 of the second filter branch 15 ranges from 36Mhz to 45 Mhz; the coupling bandwidth between the sixth filter cavity B6 of the second filter branch 15 and the seventh filter cavity B7 of the second filter branch 15 ranges from 37Mhz to 46 Mhz; the coupling bandwidth between the seventh filter cavity B7 of the second filter branch 15 and the eighth filter cavity B8 of the second filter branch 15 ranges from 40Mhz to 49 Mhz; the coupling bandwidth between the eighth filter cavity B8 of the second filter branch 15 and the second common cavity 13 ranges from 57Mhz to 68 Mhz; the coupling bandwidth between the second common cavity 13 and the third port ranges from 68Mhz to 80 Mhz.

Thus, the resonant frequency of the first common cavity 12 is in the range 1938Mhz-1940Mhz, and the resonant frequency of the second common cavity 13 is in the range 2153Mhz-2154 Mhz.

The resonant frequencies of the first filter cavity a1 through the ninth filter cavity a9 of the first filter branch 14 are in the following ranges in sequence: 1757Mhz-1759Mhz, 1744Mhz-1746Mhz, 1743Mhz-1745Mhz, and 1743Mhz-1745 Mhz.

It can be seen that the resonant frequencies of the nine filter cavities of the first filter branch 14 are substantially the same, which improves the convenience of manufacturing and tuning the filter 10, i.e. the filter can be manufactured with the same specification parameters during the manufacturing process, and the required parameter range can be achieved only by simple tuning during the actual process.

The resonant frequencies of the second filter cavity B1 through the eighth filter cavity B8 of the second filter branch 15 are sequentially in the following ranges: 2101Mhz-2103Mhz, 2181Mhz-2183Mhz, 2159Mhz-2161Mhz, 2155Mhz-2157Mhz, 2154Mhz-2156Mhz, 2153Mhz-2155 Mhz.

It can be seen that the resonant frequencies of the eight filter cavities of the second filter branch 15 are substantially the same, which improves the convenience of manufacturing and tuning the filter 10, i.e. the filter can be manufactured with the same specification parameters during the manufacturing process, and the required parameter range can be achieved only by simple tuning during the actual process.

The bandwidth of the third filtering branch 16 of the present embodiment is in the range of 1849Mhz-1996 Mhz. Specifically, the coupling bandwidth between the first port and the first common cavity 12 ranges from 128Mhz to 147 Mhz; the coupling bandwidth between the first common cavity 12 and the first filter cavity C1 of the third filter branch 16 ranges from 105Mhz to 121 Mhz; the coupling bandwidth between the first filter cavity C1 of the third filter branch 16 and the second filter cavity C2 of the third filter branch 16 ranges from 73Mhz to 86 Mhz; the coupling bandwidth between the second filter cavity C2 of the third filter branch 16 and the third filter cavity C3 of the third filter branch 16 ranges from 68Mhz to 80 Mhz; the coupling bandwidth between the third filter cavity C3 of the third filter branch 16 and the fourth filter cavity C4 of the third filter branch 16 ranges from 66Mhz to 78 Mhz; the coupling bandwidth between the fourth filter cavity C4 of the third filter branch 16 and the fifth filter cavity C5 of the third filter branch 16 ranges from 58Mhz to 69 Mhz; the coupling bandwidth between the fourth filter cavity C4 of the third filter branch 16 and the sixth filter cavity C6 of the third filter branch 16 ranges from 28Mhz to 36 Mhz; the coupling bandwidth between the fifth filter cavity C5 of the third filter branch 16 and the sixth filter cavity C6 of the third filter branch 16 ranges from 58Mhz to 69 Mhz; the coupling bandwidth between the sixth filter cavity C6 of the third filter branch 16 and the seventh filter cavity C7 of the third filter branch 16 ranges from 66Mhz to 78 Mhz; the coupling bandwidth between the seventh filter cavity C7 of the third filter branch 16 and the eighth filter cavity C8 of the third filter branch 16 ranges from 68Mhz to 80 Mhz; the coupling bandwidth between the eighth filter cavity C8 of the third filter branch 16 and the ninth filter cavity C9 of the third filter branch 16 ranges from 73Mhz to 86 Mhz; the coupling bandwidth between the ninth filter cavity C9 of the third filter branch 16 and the tenth filter cavity C10 of the third filter branch 16 ranges from 105Mhz to 121 Mhz; the coupling bandwidth between the tenth filter cavity C10 of the third filter branch 16 and the second port is in the range 128Mhz-147 Mhz.

Therefore, the resonant frequency of the first common cavity 12 is in the range 1919Mhz-1921Mhz, and the resonant frequencies of the first filter cavity C1 through the tenth filter cavity C10 of the third filter branch 16 are in the following ranges in sequence: 1919Mhz-1921Mhz, 1954Mhz-1956Mhz, 1919Mhz-1921 Mhz.

It can be seen that the resonant frequencies of the ten filter cavities of the third filter branch 16 are substantially the same, which improves the convenience of manufacturing and tuning the filter 10, i.e. the filter can be manufactured with the same specification parameters during the manufacturing process, and the required parameter range can be reached only by simple tuning during the actual process.

As shown in fig. 6, fig. 6 is a diagram showing simulation results of the filter of fig. 1. Through experimental tests, the bandwidth of the first filtering branch 14 of the present application is in the range of 1709Mhz-1781Mhz, and the bandwidth of the second filtering branch 15 is in the range of 2109Mhz-2199Mhz, as shown in the first frequency band curve 21 and the second frequency band curve 22 in fig. 6. The first filtering branch 14 has a bandwidth rejection greater than 135dB in a frequency range below 1620Mhz and above 1890 Mhz; the second filtering branch 15 has a bandwidth rejection of more than 135dB in the frequency range below 1975Mhz and above 2340 Mhz. And the maximum insertion loss (Max insertion loss) is not more than 1.5 dB; therefore, the filter 10 can have a small insertion loss while improving performance such as out-of-band rejection.

As shown in fig. 7, fig. 7 is a diagram showing simulation results of the filter in fig. 4. Through experimental tests, the bandwidth of the third filtering branch 16 of the present application is in the range of 1849Mhz to 1996Mhz, as shown by the frequency band curve 30 in fig. 7. One cross-coupling zero 161 of the filter 10 of the present application is zero a, the frequency of the zero a is 2025MHz, at this time, the bandwidth rejection is greater than 100dB, and the maximum insertion loss (Max insertion loss) is not greater than 1.5 dB; therefore, the filter 10 can have a small insertion loss while improving performance such as out-of-band rejection.

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

The present application further provides a communication system, as shown in fig. 8, fig. 8 is a schematic structural diagram of an embodiment of the communication system of the present application. The communication device 40 of this embodiment includes a terminal 43 and a base station, where the terminal 43 communicates with other terminals through the base station, the base station includes a base station antenna 42 and a Radio frequency Unit (RRU) 41, the Radio frequency Unit 41 includes the filter 10 as shown in the above embodiment, and the filter 10 is used for filtering Radio frequency signals. In other embodiments, the rf Unit 41 may be integrally designed with the base station Antenna 42 to form an Active Antenna Unit (AAU). The terminal 43 may be an electronic device such as a smart phone, a tablet computer, a notebook computer, a desktop computer, or a wearable device.

In summary, the filter 10 is connected to the first filtering branch 14 and the second filtering branch 15 through the first common cavity 12 and the second common cavity 13, and is connected to the third filtering branch 16 through the first common cavity 12, so as to implement signal transceiving, reduce the size of the filter 10, and improve the out-of-band rejection performance of the filter 10; because the filter 10 is provided with the first common cavity 12 and the second common cavity 13, the size of the filter 10 can be reduced, the number of taps can be reduced, and welding points can be reduced; the first common cavity 12, the second common cavity 13, the nine filter cavities of the first filter branch 14, the eight filter cavities of the second filter branch 15 and the ten filter cavities of the third filter branch 16 are regularly arranged, so that the space in the shell 11 can be saved, the size of the filter 10 can be reduced, and the stability of the filter 10 can be improved; nine filter cavities of the first filter branch 14, eight filter cavities of the second filter branch 15 and ten filter cavities of the third filter branch 16 of the first common cavity 12, the second common cavity 13 and the first filter branch 13 are all the same in size, so that the filter cavities in the shell 11 can be distributed and arranged at equal intervals and are arranged closely, the layout and debugging are facilitated, and the consistency of the filter 10 is improved; the zero point suppression can be realized by the arrangement of the cross-coupling zero point 161 of the third filtering branch 16, so that the debugging index is convenient, and the design requirement is met.

Some embodiments of the present application are referred to as filters, and it is understood that other embodiments may also be referred to as combiners.

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

Claims

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

2. The filter of claim 1,

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

3. The filter of claim 2,

4. The filter of claim 3,

the filter also comprises a third filtering branch, the third filtering branch is coupled with the first common cavity and consists of ten filtering cavities which are sequentially coupled, and the ten filtering cavities of the third filtering branch further form a cross-coupling zero point.

5. The filter of claim 4,

the first common cavity, the second common cavity, the nine filter cavities of the first filter branch, the eight filter cavities of the second filter branch, and the ten filter cavities of the third filter branch are divided into five columns arranged along the first direction.

6. The filter of claim 5,

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

7. The filter of claim 6,

8. The filter of claim 7,

9. The filter of claim 7, wherein the distance between the centers of any two adjacent filter cavities in the first filter branch, the second filter branch and the third filter branch is equal.

10. A communication system comprising a terminal and a base station, the base station comprising a base station antenna and a radio unit, the radio unit comprising a filter according to any of claims 1 to 9, the filter being configured to filter a radio signal.