CN113054372A

CN113054372A - Communication device and filter thereof

Info

Publication number: CN113054372A
Application number: CN201911383504.5A
Authority: CN
Inventors: 张海峰; 蔡永宏; 贺从虎; 唐梦军
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 filter. The filter includes: a housing having a first direction and a second direction perpendicular to each other; a first port disposed on the housing; the first filtering branch is connected with the first port and consists of six filtering cavities which are sequentially coupled, and the six filtering cavities of the first filtering branch form a capacitive cross-coupling zero point; and the second filtering branch is connected with the first port and consists of six filtering cavities which are sequentially coupled, and the six filtering cavities of the second filtering branch are arranged in an L shape. Therefore, the first filtering branch and the second filtering branch of the filter provided by the application share the taps, the number of the taps and the welding points are reduced, the size of the filter is reduced, and the cost is reduced.

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 precisely control its bandwidth.

The inventor of the present application finds, in long-term research and development work, that the existing filter is provided with a plurality of filter branches, and each filter branch needs to be provided with an input port and an output port, so that the number of taps of the filter is large, the size of the filter is large, and the cost is high.

Disclosure of Invention

The application provides a filter to solve the technical problems of large size and high cost of the filter in the prior art.

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

a housing having a first direction and a second direction perpendicular to the first direction;

a first port disposed on the housing;

the first filtering branch is connected with the first port and consists of six filtering cavities which are sequentially coupled, and the six filtering cavities of the first filtering branch form a capacitive cross-coupling zero point;

and the second filtering branch is connected with the first port and consists of six filtering cavities which are sequentially coupled, and the six filtering cavities of the second filtering branch are arranged in an L shape.

The sixth filtering cavity of the first filtering branch is connected with the first port;

the second filter cavity of the first filter branch is far away from the middle branching line of the shell in the first direction relative to the first filter cavity, so that an included angle between a connecting line of the center of the first filter cavity of the first filter branch and the center of the second filter cavity and the middle branching line is an acute angle;

the second filter cavity, the fourth filter cavity, the fifth filter cavity and the sixth filter cavity of the first filter branch are in a row and are arranged along the second direction, and the second filter cavity and the fourth filter cavity of the first filter branch are arranged at intervals;

the third filtering cavity, the second filtering cavity and the fourth filtering cavity of the first filtering branch are arranged adjacently, and the projection of the first filtering cavity of the first filtering branch in the first direction is located between the projection of the first filtering cavity of the first filtering branch in the first direction and the projection of the third filtering cavity of the first filtering branch in the first direction.

The sixth filtering cavity of the second filtering branch is connected with the first port;

the sixth filter cavity, the fifth filter cavity, the fourth filter cavity and the third filter cavity of the second filter branch are in a row and are arranged along the first direction, and the fifth filter cavity of the second filter branch is respectively intersected with the fourth filter cavity and the sixth filter cavity of the second filter branch;

and the third filtering cavity, the second filtering cavity and the first filtering cavity of the second filtering branch are arranged in a row and along the second direction, and the second filtering cavity of the second filtering branch is respectively intersected with the first filtering cavity and the third filtering cavity of the second filtering branch.

And the second filter cavity and the fourth filter cavity of the first filter branch are capacitively and cross-coupled to form a cross-coupling zero point of the first filter branch.

The filter further comprises a third filtering branch and a second port, the second port is connected with the first port, and the third filtering branch is composed of four filtering cavities which are sequentially coupled.

The second filter cavities, the third filter cavities and the fourth filter cavities of the third filter branch are arranged in a row and along the first direction, and the first filter cavities of the third filter branch are intersected with the first filter cavities of the second filter branch and the second filter cavities of the third filter branch respectively. The number of welding points and taps is reduced, the production cost is reduced, and meanwhile the flexibility of configuration is improved.

The filter further comprises a fourth filtering branch and a second port, the fourth filtering branch is connected with the second port and consists of six filtering cavities which are sequentially coupled, and the six filtering cavities of the fourth filtering branch are arranged in a C shape.

The first filtering cavities, the second filtering cavities and the third filtering cavities of the fourth filtering branch are in a row and are arranged along the first direction, and the fourth filtering cavities, the fifth filtering cavities and the sixth filtering cavities of the fourth filtering branch are in a row and are close to the central line of the second direction;

the second filter cavity of the fourth filter branch is respectively intersected with the first filter cavity and the third filter cavity of the fourth filter branch, the fourth filter cavity of the fourth filter branch is respectively intersected with the third filter cavity and the fifth filter cavity of the fourth filter branch, and the sixth filter cavity of the fourth filter branch is respectively intersected with the fifth filter cavity and the second port of the fourth filter branch;

the projection of the fourth filter cavity of the fourth filter branch in the first direction is positioned between the projections of the second filter cavity and the third filter cavity of the fourth filter branch in the first direction;

and a fourth filter cavity of the fourth filter branch is arranged adjacent to the first filter cavity of the third filter branch, and a sixth filter cavity of the fourth filter branch is arranged adjacent to the third filter cavity of the first filter branch.

Wherein the bandwidth of the first filtering branch is in the range of 1850Mhz-1995 Mhz;

the bandwidth of the second filtering branch circuit is in the range of 1695Mhz-1780 Mhz;

the bandwidth of the third filtering branch is in a range of 2110Mhz-2200 Mhz;

the bandwidth of the fourth filtering branch is in the range of 2305Mhz-2690 Mhz.

To solve the above problem, the present application further provides a communication device comprising an antenna and a radio frequency unit connected to the antenna, the radio frequency unit comprising the filter of any one of claims 1 to 9 for filtering a radio frequency signal.

Compared with the prior art, the first filtering branch and the second filtering branch of the filter of the application are connected with the first port, namely the first filtering branch and the second filtering branch share the tap, the number and the welding point of the tap are reduced, the size of the filter is reduced, and the cost is reduced. The six filter cavities of the first filter branch form a capacitive cross coupling zero point, only capacitive cross coupling is arranged, the types of materials are reduced, and the consistency of the materials is improved; in addition, six filtering cavities of the second filtering branch are arranged in an L shape and are regularly arranged, so that the size of the filtering cavities is reduced, and the stability of the filter is improved.

Drawings

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

FIG. 1 is a schematic structural diagram of a first 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 provided in the present application;

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

fig. 4 is a diagram illustrating simulation results of a first filtering branch of the filter provided in the present application;

FIG. 5 is a diagram illustrating simulation results of a second filtering branch of the filter provided in the present application;

fig. 6 is a schematic structural diagram of a second embodiment of the filter provided in the present application;

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

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

fig. 9 is a schematic diagram of simulation results of a third filtering branch and a fourth filtering branch of the filter provided in the present application;

fig. 10 is a schematic structural diagram of an embodiment of a 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 first embodiment is as follows:

the present application provides a first embodiment of a filter 10, as shown in fig. 1, fig. 1 is a schematic structural diagram of the first embodiment of the filter 10 of the present application.

The filter 10 of the embodiment of the present application includes a housing 11, a first port G1, a first filtering branch 12, and a second filtering branch 13. The first and

second filter branches

12, 13 may be receive filter branches or transmit filter branches.

The housing 11 has a first direction D and a second direction L perpendicular to each other, and the first filtering branch 12 and the second filtering branch 13 are connected to the first port G1 at the same time. Therefore, the first filtering branch 12 and the second filtering branch 13 of the filter 10 of the present application are both connected to the first port G1, that is, the first filtering branch 12 and the second filtering branch 13 share a tap, so that the number of taps and the welding point are reduced, the size of the filter 10 is reduced, and the cost is reduced. And the second filtering branch 13 consists of six filtering cavities which are coupled in sequence. Six filter cavities of the second filter branch 13 are arranged in an L shape; the first filtering branch 12 is composed of six filtering cavities coupled in sequence to form a capacitive cross coupling zero point 16, so that the filter 10 provided by the present application is only provided with capacitive cross coupling, the variety of materials is reduced, and the consistency of the materials is improved.

In particular, the sixth filtering chamber a6 of the first filtering branch 12 is connected to the first port G1. The second filter cavity a2 of the first filter branch 12 is separated from the central line of the first filter cavity a1 of the housing 11 in the first direction D, so that an included angle between a connecting line of the center of the first filter cavity a1 of the first filter branch 12 and the center of the second filter cavity a2 and the central line is an acute angle; the second filtering cavity a2, the fourth filtering cavity a4, the fifth filtering cavity a5 and the sixth filtering cavity a6 of the first filtering branch 12 are in a row and are arranged along the second direction L, and the second filtering cavity a2 and the fourth filtering cavity a4 of the first filtering branch 12 are arranged at intervals; the third filtering cavity A3 and the second filtering cavity a2 of the first filtering branch 12 are disposed adjacent to the fourth filtering cavity a4, and the projection of the first filtering cavity a1 of the first filtering branch 12 in the first direction D is located between the projection of the second filtering cavity a2 and the third filtering cavity A3 of the first filtering branch 12 in the first direction D.

The sixth filtering cavity B6 of the second filtering branch 13 is connected with the first port G1; the sixth filtering cavity B6, the fifth filtering cavity B5, the fourth filtering cavity B4 and the third filtering cavity B3 of the second filtering branch 13 are in a row and arranged along the first direction D, and the fifth filtering cavity B5 of the second filtering branch 13 is respectively intersected with the fourth filtering cavity B4 and the sixth filtering cavity B6 of the second filtering branch 13.

The third filter cavity B3, the second filter cavity B2 and the first filter cavity B1 of the second filter branch 13 are aligned in a row and arranged along the second direction L. Therefore, the filter cavities in the filter 10 are regularly arranged, the size of the filter 10 is reduced, and the stability of the filter 10 is improved. The second filter cavity B2 of the second filter branch 13 intersects with the first filter cavity B1 and the third filter cavity B3 of the second filter branch 13, respectively.

It should be noted that the filter 10 provided in the present application has a coupling window (not shown) disposed between the intersection positions of two intersecting filter cavities, and the width of the coupling window is equal to the distance between the intersection points. The filter cavities are arranged in an intersecting manner, so that a separation wall is prevented from being arranged between two coupled filter cavities in the traditional filter, and then a coupling window is arranged on the separation wall, so that materials are reduced, the processing is convenient, and the cost is saved; in addition, the distance between the two coupled filter cavities in the filter is reduced, and the coupling strength between the two filter cavities is improved.

Referring to fig. 1, 2 and 3, fig. 1 is a schematic structural diagram of a first embodiment of a filter 10 according to the present application; fig. 2 is a schematic diagram of a topology of a first filtering branch 12 of the filter 10 provided in the present application; fig. 3 is a schematic diagram of a topology of the second filtering branch 13 of the filter 10 provided in the present application.

In the first embodiment of the present application, the second filter cavity a2 and the fourth filter cavity a4 of the first filter branch 12 are capacitively cross-coupled to form a cross-coupled zero 16 of the first filter branch 12.

Specifically, a window may be disposed between the second filter cavity a2 and the fourth filter cavity a4 of the first filter branch 12, and a flying bar may be disposed at the window, so that capacitive cross-coupling is achieved between the second filter cavity a2 and the fourth filter cavity a4 of the first filter branch 12 to form a capacitive cross-coupling zero 16, which is equivalent to the capacitor C111 shown in fig. 2.

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

Optionally, a third port and a fourth port may be further provided in the housing 11. The third port is connected to the first filter cavity a1 of the first filter branch 12, and the fourth port is connected to the first filter cavity B1 of the second filter branch 13. Wherein the third port and the fourth port may be taps of the filter 10.

Referring to fig. 1 and 2, fig. 1 is a schematic structural diagram of a first embodiment of a filter 10 according to the present application; fig. 2 is a schematic diagram of a topology of the first filtering branch 12 of the filter 10 provided in the present application.

The first filtering branch 12 of the present embodiment may be a transmitting filtering branch. Wherein the bandwidth of the first filtering branch 12 is in the range of 2305Mhz-2690 Mhz. Specifically, the coupling bandwidth between the third port and the first filter cavity a1 of the first filter branch 12 ranges from 389Mhz to 437 Mhz; the coupling bandwidth between the first cavity a1 of the first filter branch 12 and the second cavity a2 of the first filter branch 12 ranges from 326Mhz to 367 Mhz; the coupling bandwidth between the second filter cavity a2 of the first filter branch 12 and the third filter cavity A3 of the first filter branch 12 ranges from 201Mhz to 228 Mhz; the coupling bandwidth between the second filter cavity a2 of the first filter branch 12 and the fourth filter cavity a4 of the first filter branch 12 ranges from-135 Mhz-125 Mhz; the coupling bandwidth between the third filter cavity A3 of the first filter branch 12 and the fourth filter cavity a4 of the first filter branch 12 ranges from 189Mhz to 215 Mhz; the coupling bandwidth between the fourth filter cavity a4 of the first filter branch 12 and the fifth filter cavity a5 of the first filter branch 12 ranges from 235Mhz to 267 Mhz; the coupling bandwidth between the fifth cavity a5 of the first filter branch 12 and the sixth cavity a6 of the first filter branch 12 ranges from 326Mhz to 367 Mhz; the coupling bandwidth of the sixth filter cavity a6 and the first port G1 of the first filter branch 12 ranges from 389Mhz to 437 Mhz; therefore, the bandwidth of the first filtering branch 12 of the filter 10 of the present embodiment is in the range of 2305Mhz-2690Mhz, which can meet the design requirement.

Therefore, the resonant frequencies of the first filter cavity a1 through the sixth filter cavity a6 of the first filter branch 12 are in the following ranges: 2485Mhz-2489 Mhz; 2486Mhz-2490 Mhz; 2362Mhz-2366 Mhz; 2489Mhz-2493 Mhz; 2486Mhz-2490 Mhz; 2485Mhz-2489 Mhz.

Referring to fig. 4, fig. 4 is a diagram illustrating simulation results of the first filtering branch 12 in the filter 10 shown in fig. 1.

Experimentally, the bandwidth of the first filtering branch 12 of the filter 10 of the present application is in the range 2305Mhz-2690Mhz, as shown by the band curve 20 in fig. 4. Wherein the bandwidth rejection is greater than 37dB at a frequency of 1847Mhz to 1998Mhz in the graph; when the frequency is 1692Mhz-1783Mhz, the bandwidth inhibition is more than 37 dB; at a frequency of 2107Mhz-2203Mhz, the bandwidth rejection is greater than 37 dB. Therefore, the performance of the filter 10 such as out-of-band rejection can be improved.

Referring to fig. 1 and 3, fig. 1 is a schematic structural diagram of a first embodiment of a filter 10 according to the present application; fig. 3 is a schematic diagram of a topology of the second filtering branch 13 of the filter 10 provided in the present application.

The second filtering branch 13 of the present embodiment may be a transmitting filtering branch. Wherein the bandwidth of the second filter branch 13 lies in the range of 1850Mhz-1995 Mhz.

Specifically, the coupling bandwidth between the fourth port and the first filter cavity B1 of the second filter branch 13 is in the range of 128Mhz-148 Mhz; the coupling bandwidth between the first filter cavity B1 of the second filter branch 13 and the second filter cavity B2 of the second filter branch 13 ranges from 109Mhz to 124 Mhz; the coupling bandwidth between the second filter cavity B2 of the second filter branch 13 and the third filter cavity B3 of the second filter branch 13 ranges from 77Mhz to 91 Mhz; the coupling bandwidth between the third filter cavity B3 of the second filter branch 13 and the fourth filter cavity B4 of the second filter branch 13 ranges from 73Mhz to 87 Mhz; the coupling bandwidth between the fourth filter cavity B4 of the second filter branch 13 and the fifth filter cavity B5 of the second filter branch 13 ranges from 77Mhz to 91 Mhz; the coupling bandwidth between the fifth filter cavity B5 of the second filter branch 13 and the sixth filter cavity B6 of the second filter branch 13 ranges from 109Mhz to 124 Mhz; the coupling bandwidth between the sixth filter cavity B6 of the second filter branch 13 and the first port G1 ranges from 128Mhz to 148 Mhz. Therefore, the bandwidth of the second filtering branch 13 of the filter 10 of the present embodiment is in the range of 1850Mhz-1995Mhz, which can meet the design requirement.

Therefore, the resonant frequencies of the first through sixth filter cavities B1-B6 of the second filter branch 13 lie in the following ranges: 1919Mhz-1923 Mhz; 1919Mhz-1923 Mhz; 1919Mhz-1923 Mhz; 1919Mhz-1923 Mhz; 1919Mhz-1923 Mhz; 1919Mhz-1923 Mhz.

Referring to fig. 5, fig. 5 is a diagram illustrating simulation results of the second filtering branch 13 in the filter 10 shown in fig. 1.

Experimentally tested, the bandwidth of the second filtering branch 13 of the filter 10 of the present application lies in the range of 1850Mhz-1995Mhz, as shown by the band curve 30 in fig. 5. Wherein the bandwidth rejection is greater than 37dB at frequencies 1692Mhz-1783Mhz in the graph; when the frequency is 2107Mhz-2203Mhz, the bandwidth inhibition is more than 37 dB; at frequencies from 2302Mhz to 5928Mhz, the bandwidth rejection is greater than 37 dB. Therefore, the performance of the filter 10 such as out-of-band rejection can be improved.

It is noted that the parameters of two or more coupling zeros of the present application may be the same; in the simulation diagram, the coupling zeros of the same parameters are shown as the same coupling zeros.

Example two:

referring to fig. 6, fig. 6 is a schematic structural diagram of a second embodiment of the filter 10 provided in the present application.

The filter 10 provided by the present application further includes a third filtering branch 14, a fourth filtering branch 15 and a second port G2, the second port G2 is connected with the first port G1, the third filtering branch 14 and the fourth filtering branch 15 are both connected with the second port G2, that is, the third filtering branch 14 and the fourth filtering branch 15 share a tap, the number and the welding point of the tap are reduced, the size of the filter 10 is reduced, and the cost is reduced. The third filtering branch 14 is composed of four filtering cavities which are coupled in sequence; the fourth filtering branch 15 is composed of six filtering cavities coupled in sequence, wherein the six filtering cavities of the fourth filtering branch 15 are arranged in a C-shape.

The second filtering cavity C2, the third filtering cavity C3 and the fourth filtering cavity C4 of the third filtering branch 14 are in a row and are arranged along the first direction D, and the first filtering cavity C1 of the third filtering branch 14 is intersected with the first filtering cavity B1 of the second filtering branch 13 and the second filtering cavity C2 of the third filtering branch 14.

The first filter cavity D1, the second filter cavity D2 and the third filter cavity D3 of the fourth filter branch 15 are aligned in a row and are arranged along the first direction D, and the fourth filter cavity D4, the fifth filter cavity D5 and the sixth filter cavity D6 of the fourth filter branch 15 are aligned in a row and are close to the center line of the second direction L.

The second filtering cavity D2 of the fourth filtering branch 15 intersects with the first filtering cavity D1 and the third filtering cavity D3 of the fourth filtering branch 15, the fourth filtering cavity D4 of the fourth filtering branch 15 intersects with the third filtering cavity D3 and the fifth filtering cavity D5 of the fourth filtering branch 15, and the sixth filtering cavity D6 of the fourth filtering branch 15 intersects with the fifth filtering cavity D5 and the second port G2 of the fourth filtering branch 15.

The projection of the fourth filter cavity D4 of the fourth filter branch 15 in the first direction D is located between the projections of the second filter cavity D2 and the third filter cavity D3 of the fourth filter branch 15 in the first direction D.

The fourth filter cavity D4 of the fourth filter branch 15 is disposed adjacent to the first filter cavity C1 of the third filter branch 14, and the sixth filter cavity D6 of the fourth filter branch 15 is disposed adjacent to the third filter cavity A3 of the first filter branch 12.

Optionally, the housing 11 may be further provided with a fifth port and a sixth port. The fifth port is connected to the first filter cavity C1 of the third filter branch 14, and the sixth port is connected to the first filter cavity D1 of the fourth filter branch 15. Wherein the fifth port and the sixth port may be taps of the filter 10.

Referring to fig. 6, 7 and 8, fig. 6 is a schematic structural diagram of a second embodiment of the filter 10 provided in the present application; fig. 7 is a schematic diagram of the topology of the third filtering branch 14 of the filter 10 provided in the present application; fig. 8 is a schematic diagram of a topology of the fourth filtering branch 15 of the filter 10 provided in the present application.

The third filtering branch 14 and the fourth filtering branch 15 in this embodiment may be a combined branch. Wherein the bandwidth of the third filtering branch 14 is in the range 1695Mhz-1780 Mhz. In particular, the coupling bandwidth between the fifth port and the first filter cavity C1 of the third filter branch 14 is in the range of 277Mhz-312 Mhz; the coupling bandwidth between the first filter cavity C1 of the third filter branch 14 and the second filter cavity C2 of the third filter branch 14 ranges from 72Mhz to 85 Mhz; the coupling bandwidth between the second filter cavity C2 of the third filter branch 14 and the third filter cavity C3 of the third filter branch 14 ranges from 57Mhz to 68 Mhz; the coupling bandwidth between the third filter cavity C3 of the third filter branch 14 and the fourth filter cavity C4 of the third filter branch 14 ranges from 75Mhz to 88 Mhz; the coupling bandwidth between the fourth filter cavity C4 and the second port G2 of the third filter branch 14 ranges from 87Mhz to 104 Mhz; therefore, the bandwidth of the third filtering branch 14 of the filter 10 of the present embodiment is in the range of 1695Mhz to 1780Mhz, which can meet the design requirement.

Therefore, the resonant frequencies of the first through fourth filter cavities C1-C4 of the third filter branch 14 lie in the following ranges: 1749Mhz-1753 Mhz; 1736Mhz-1740 Mhz; 1735Mhz-1739 Mhz; 1735Mhz-1739 Mhz.

Wherein the bandwidth of the fourth filtering branch 15 is in the range of 2110Mhz-2200 Mhz. In particular, the coupling bandwidth between the sixth port and the first filter cavity D1 of the fourth filter branch 15 ranges from 250Mhz to 283 Mhz; the coupling bandwidth between the first filter cavity D1 of the fourth filter branch 15 and the second filter cavity D2 of the fourth filter branch 15 ranges from 57Mhz to 68 Mhz; the coupling bandwidth between the second filter cavity D2 of the fourth filter branch 15 and the third filter cavity D3 of the fourth filter branch 15 ranges from 42Mhz to 52 Mhz; the coupling bandwidth between the third filter cavity D3 of the fourth filter branch 15 and the fourth filter cavity D4 of the fourth filter branch 15 ranges from 40Mhz to 49 Mhz; the coupling bandwidth between the fourth filter cavity D4 of the fourth filter branch 15 and the fifth filter cavity D5 of the fourth filter branch 15 ranges from 42Mhz to 52 Mhz; the coupling bandwidth between the fifth filter cavity D5 of the fourth filter branch 15 and the sixth filter cavity D6 of the fourth filter branch 15 ranges from 59Mhz to 70 Mhz; the coupling bandwidth between the sixth filter cavity D6 and the second port G2 of the fourth filter branch 15 ranges from 71Mhz to 83 Mhz; therefore, the bandwidth of the fourth filtering branch 14 of the filter 10 of the present embodiment is within a range from 2110Mhz to 2200Mhz, which can meet the design requirement.

Therefore, the resonant frequencies of the first through sixth filter cavities D1-D6 of the fourth filter branch 15 lie in the following ranges: 2138Mhz-2142 Mhz; 2151Mhz-2155 Mhz; 2152Mhz-2156 Mhz; 2152Mhz-2156 Mhz; 2152Mhz-2156 Mhz; 2152Mhz-2156 Mhz.

Referring to fig. 9, fig. 9 is a diagram illustrating simulation results of the third filtering branch 14 and the fourth filtering branch 15 in the filter 10 shown in fig. 6.

Through experimental tests, the bandwidth of the third filtering branch 14 of the filter 10 of the present application is in the range of 1695Mhz-1780Mhz, as shown by the frequency band curve 40 in fig. 9; the bandwidth of the fourth filtering branch 15 of the filter 10 of the present application lies in the range 2110Mhz to 2200Mhz, as shown by the frequency band curve 50 in fig. 9. Wherein the bandwidth rejection is greater than 37dB at a frequency of 1847Mhz to 1998Mhz in the graph; at frequencies from 2302Mhz to 5928Mhz, the bandwidth rejection is greater than 37 dB. Therefore, the performance of the filter 10 such as out-of-band rejection can be improved.

The present application further provides a communication device 60, as shown in fig. 10, fig. 10 is a schematic structural diagram of an embodiment of the communication device 60 of the present application. The communication device 60 of the present embodiment includes an antenna 62 and a Radio Unit 61(Remote Radio Unit, RRU), and the Radio Unit 61 further includes a filter 10 for filtering a Radio frequency signal. In other embodiments, the rf Unit 61 may be integrally designed with the Antenna 62 to form an Active Antenna Unit (AAU), wherein the filter 10 may be the above-mentioned filter 10, and will not be described herein again.

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

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

Claims

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

a first port disposed on the housing;

2. The filter of claim 1,

3. The filter of claim 2,

a sixth filtering cavity of the second filtering branch is connected with the first port;

4. The filter of claim 2,

5. The filter of claim 3,

the filter further comprises a third filtering branch and a second port, the second port is connected with the first port, the third filtering branch is connected with the second port, and the third filtering branch is composed of four filtering cavities which are sequentially coupled.

6. The filter of claim 5,

the second filtering cavities, the third filtering cavities and the fourth filtering cavities of the third filtering branch are arranged in a row and along the first direction, and the first filtering cavities of the third filtering branch and the first filtering cavities of the second filtering branch and the second filtering cavities of the third filtering branch are respectively arranged in an intersecting manner.

7. The filter of claim 6,

the filter further comprises a fourth filtering branch and the second port is connected, six filtering cavities which are sequentially coupled are formed, and the six filtering cavities of the fourth filtering branch are arranged in a C shape.

8. The filter of claim 7,

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

9. The filter of claim 8,

the bandwidth of the first filtering branch is in the range of 1850Mhz-1995 Mhz;

the bandwidth of the third filtering branch is in a range of 2110Mhz-2200 Mhz;

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 radio frequency signals.