CN113054347A

CN113054347A - Filter and communication equipment

Info

Publication number: CN113054347A
Application number: CN201911380989.2A
Authority: CN
Inventors: 张海峰; 蔡永宏; 张宝真; 宋文刚
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 wave filter and communication equipment, this wave filter includes: a housing having a first direction and a second direction perpendicular to the first direction; a common chamber disposed on the housing; the first filtering branch circuit is coupled with the common cavity and consists of six filtering cavities which are sequentially coupled, and the six filtering cavities of the first filtering branch circuit form two inductive cross-coupling zeros; and the second filtering branch circuit is coupled with the public cavity and consists of six filtering cavities which are sequentially coupled, and the six filtering cavities of the second filtering branch circuit form two capacitive cross-coupling zeros. Through the mode, the first filtering branch and the second filtering branch share the taps, so that the tap quantity of the filter is reduced, the space of the filter occupied by the taps is reduced, the size of the filter is reduced, and the cost is reduced.

Description

Filter and communication equipment

Technical Field

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

Background

In a mobile communication device, 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 that the wave filter is provided with first filtering branch road and second filtering branch road among the prior art, and first filtering branch road and second filtering branch road all need independently to set up the tap of input and output, and it is many to take a percentage, occupy the space of wave filter, lead to the wave filter bulky, with high costs.

Disclosure of Invention

The application provides a filter to solve the technical problem that filters are large in size and high in cost in the prior art.

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 common chamber disposed on the housing;

the first filtering branch circuit is coupled with the common cavity and consists of six filtering cavities which are sequentially coupled, and the six filtering cavities of the first filtering branch circuit comprise two inductive cross-coupling zeros;

and the second filtering branch circuit is coupled with the common cavity and consists of six filtering cavities which are sequentially coupled, and the six filtering cavities of the second filtering branch circuit comprise two capacitive cross-coupling zeros. Because the first filtering branch and the second filtering branch are coupled with the common cavity and share the taps, the number of taps of the filter is reduced, the space occupied by the taps of the filter is reduced, the size of the filter is reduced, and the cost is reduced.

Optionally, the common cavity, the first filter branch and the second filter branch are divided into four columns arranged along the first direction, and the first filter cavity of the first filter branch and the first filter cavity of the second filter branch are coupled with the common cavity;

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

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

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

and the second filtering cavity, the third filtering cavity and the fifth filtering cavity of the second filtering branch are in a row and are sequentially arranged along the second direction. The common cavity, the first filtering branch and the second filtering branch are divided into four rows, namely the filtering cavities of the filter are regularly arranged, so that the design and debugging of the filter are facilitated.

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

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

the second filtering cavity of the first filtering branch is respectively adjacent to the common cavity, the first filtering cavity of the first filtering branch, the third filtering cavity and the fourth filtering cavity. Because the partial filter cavity of the second filter branch is adjacent to the partial filter cavity of the first filter branch, the distance between the common cavity, the first filter branch and the second filter branch is reduced, so that the filter cavities of the filter are arranged closely, and the size of the filter is further reduced.

Optionally, the sixth filtering cavity of the first filtering branch is respectively intersected with the fourth filtering cavity and the fifth filtering cavity of the first filtering branch;

and the sixth filter cavity of the second filter branch is respectively intersected with the fifth filter cavity of the first filter branch, the fourth filter cavity of the second filter branch and the fifth filter cavity. The crossed arrangement of the filter cavities avoids the situation that a separation wall needs to be 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.

Optionally, the first filter cavity and the third filter cavity of the first filter branch, and the fourth filter cavity and the sixth filter cavity of the first filter branch are inductively cross-coupled, respectively, to form two inductive cross-coupling zeros of the first filter branch;

capacitive cross coupling is respectively performed between a second filtering cavity and a fourth filtering cavity of the second filtering branch circuit and between the fourth filtering cavity and a sixth filtering cavity of the second filtering branch circuit, so that two capacitive cross coupling zeros of the second filtering branch circuit are formed. Because the first filtering branch is provided with the two inductive cross coupling zero points, and the second filtering branch is provided with the two capacitive cross coupling zero points, the isolation between the first filtering branch and the second filtering branch can be improved, and the suppression performance of the pass bands of the first filtering branch and the second filtering branch can be improved.

Optionally, the bandwidth range of the first filtering branch is: 789 and 863 MHz;

the bandwidth range of the second filtering branch is as follows: 879 and 961 MHz. Therefore, the first filtering branch and the second filtering branch both meet the design requirements, and the bandwidths of the first filtering branch and the second filtering branch can be accurately controlled.

Optionally, the filter cavity includes a third filter branch and a first port, the common cavity and the third filter branch are connected to the first port, and the third filter branch and the second filter branch are arranged at an interval along the first direction. Because the third filtering branch and the common cavity share the first port, the number of taps is further reduced, welding points are reduced, and the cost is reduced.

Optionally, the third filtering branch is composed of six sequentially coupled filtering cavities, and the first filtering cavity, the second filtering cavity, the third filtering cavity, the fourth filtering cavity, the fifth filtering cavity and the sixth filtering cavity of the third filtering branch are in a row and are sequentially arranged along the second direction. The third filtering branches are arranged linearly and regularly, so that the space occupied by the third filtering branches can be reduced, the size of the filter is reduced, and the design is easy.

Optionally, the bandwidth range of the third filtering branch is: 1707 and 2703 MHz. Therefore, the third filtering branch circuit meets the design requirement, and the bandwidth of the third filtering branch circuit can be accurately controlled.

The embodiment of the application also provides communication equipment, which comprises an antenna and a radio frequency unit connected with the antenna, wherein the radio frequency unit comprises the filter for filtering the radio frequency signal.

Be different from prior art's condition, first filtering branch road and second filtering branch road all with public chamber coupling, the sharing of this application is taken a percentage, consequently reduces the quantity of taking a percentage of wave filter, reduces the space of taking a percentage shared wave filter, reduces the volume of wave filter, reduce cost. In addition, two inductive cross-coupling zeros are arranged in the six filter cavities of the first filter branch and two capacitive cross-coupling zeros are arranged in the six filter cavities of the second filter branch, so that the suppression performance of the pass bands of the first filter branch and the second filter branch 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 provided in the present application;

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

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

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

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

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

fig. 7 is a schematic structural diagram of an embodiment of a communication device provided in the present application;

fig. 8 is a diagram illustrating simulation results of a second filtering branch provided in the present application;

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

Detailed Description

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

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

Referring to fig. 1, fig. 1 is a schematic structural diagram of a first embodiment of a filter provided in the present application. The filter of the present embodiment includes a housing 11, a common cavity 12, a first filter branch 13 and a second filter branch 14, the housing 11 has a first direction L1 and a second direction L2 perpendicular to the first direction L1, the first direction L1 may be a length direction of the housing 11, and the second direction L2 may be a width direction of the housing 11.

As shown in fig. 1, the common cavity 12 is disposed on the housing 11, the first filtering branch 13 is coupled to the common cavity 12, and the second filtering branch 14 is coupled to the common cavity 12, that is, the first filtering branch 13 and the second filtering branch 14 share a tap, so that the number of taps of the filter is reduced, the space occupied by the taps is reduced, the size of the filter is reduced, and the cost is reduced. The first filtering branch 13 consists of six filtering cavities which are coupled in sequence, and the six filtering cavities of the first filtering branch 13 are a first filtering cavity a1, a second filtering cavity a2, a third filtering cavity A3, a fourth filtering cavity a4, a fifth filtering cavity a5 and a sixth filtering cavity a6 of the first filtering branch 13; the six filter cavities of the first filter branch 13 include two inductive cross-coupling zeros, which are all inductive cross-coupling, so that the material consistency of the first filter branch 13 is good. The second filtering branch 14 is composed of six filtering cavities coupled in sequence, the six filtering cavities of the second filtering branch 14 are a first filtering cavity B1, a second filtering cavity B2, a third filtering cavity B3, a fourth filtering cavity B4, a fifth filtering cavity B5 and a sixth filtering cavity B6 of the second filtering branch 14, and the six filtering cavities of the second filtering branch 14 include two capacitive cross-coupling zeros which are both capacitive cross-coupling, so that the material consistency of the second filtering branch 14 is good, and the complexity of the filter is further reduced.

In particular, common cavity 12, first filtering branch 13 and second filtering branch 14 are divided into four columns arranged along first direction L1, first filtering cavity a1 of first filtering branch 13 and first filtering cavity B1 of second filtering branch 14 being coupled to common cavity 12. As shown in fig. 1, the first filter cavity a1, the second filter cavity a2, the fourth filter cavity a4 and the sixth filter cavity a6 of the first filter branch 13 are in a row and are sequentially arranged along the second direction L2; the common cavity 12, the third filter cavity A3 and the fifth filter cavity a5 of the first filter branch 13 are in a row and are sequentially arranged along a second direction L2; the first filtering cavity B1, the fourth filtering cavity B4 and the sixth filtering cavity B6 of the second filtering branch 14 are in a row and are sequentially arranged along the second direction L2; the second filter cavity B2, the third filter cavity B3 and the fifth filter cavity B5 of the second filter branch 14 are in a row and are sequentially arranged along the second direction L2. Therefore, the common cavity 12, the first filtering branch 13 and the second filtering branch 14 can be divided into four rows, that is, the filtering cavities of the filter are regularly arranged, which is convenient for designing and debugging the filter.

As shown in fig. 1, the fourth filter cavity B4 of the second filter branch 14 is respectively disposed adjacent to the first filter cavity B1, the third filter cavity B3 and the fifth filter cavity B5 of the second filter branch 14, and the fifth filter cavity a5 and the third filter cavity A3 of the first filter branch 13; the first filtering cavity B1 of the second filtering branch 14 is respectively adjacent to the common cavity 12, the third filtering cavity A3 of the first filtering branch 13, and the second filtering cavity B2, the third filtering cavity B3 and the fourth filtering cavity B4 of the second filtering branch 14; the second filter cavity a2 of the first filter branch 13 is respectively disposed adjacent to the common cavity 12, the first filter cavity a1, the third filter cavity A3 and the fourth filter cavity a4 of the first filter branch 13. Because the partial filter cavity of the second filter branch 14 is adjacent to the partial filter cavity of the first filter branch 13, the distance between the common cavity 12, the first filter branch 13 and the second filter branch 14 can be reduced, so that the filter cavities of the filter are arranged closely, and the size of the filter is further reduced.

The sixth filtering cavity a6 of the first filtering branch 13 intersects with the fourth filtering cavity a4 and the fifth filtering cavity a5 of the first filtering branch 13 respectively; taking the sixth filter chamber a6 and the fourth filter chamber a4 of the first filter branch 13 as an example, the sixth filter chamber a6 and the fourth filter chamber a4 intersect to form intersections D and E, and the intersection of the sixth filter chamber a6 and the fourth filter chamber a4 is a coupling window (not shown) provided between the sixth filter chamber a6 and the fourth filter chamber a4, and the width of the coupling window is equal to the distance between the intersections D and E. The sixth filter cavity B6 of the second filter branch 14 intersects with the fifth filter a5 of the first filter branch 13, the fourth filter cavity B4 of the second filter branch 14 and the fifth filter cavity B5, respectively. 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 and 2, fig. 2 is a schematic diagram of a topology structure of a first filtering branch provided in the present application, in which a second filtering cavity a2 and a fourth filtering cavity a4 of the first filtering branch 13 and a fourth filtering cavity a4 and a sixth filtering cavity a6 of the first filtering branch 13 are inductively cross-coupled to form two inductive cross-coupling zeros of the first filtering branch 13, respectively. Usually, the inductive cross-coupling element may be a metal coupling rib, that is, a metal coupling rib is disposed between the first filter cavity a1 and the third filter cavity A3 of the first filter branch 13. The first filtering branch 13 realizes zero suppression by setting two inductive cross-coupling zeros, so that the first filtering branch 13 meets design requirements, and debugging is facilitated.

The cross-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.

Referring to fig. 1 and 3, fig. 3 is a schematic diagram of a topology structure of the second filtering branch provided in the present application, wherein capacitive cross coupling is respectively performed between the first filtering cavity B1 and the third filtering cavity B3 of the second filtering branch 14 and between the fourth filtering cavity B4 and the sixth filtering cavity B6 of the second filtering branch 14, so as to form two capacitive cross coupling zeros of the second filtering branch 14. Typically, the capacitive cross-coupling element may be a flying rod, i.e. a flying rod is arranged between the first filter cavity a1 and the third filter cavity A3 of the second filter branch 14. The second filtering branch 14 realizes zero suppression by setting two capacitive cross-coupling zeros, so that the second filtering branch 14 meets design requirements, and debugging is facilitated.

Because two inductive cross-coupling zero points are arranged on the first filtering branch 13 and two capacitive cross-coupling zero points are arranged on the second filtering branch 14, the isolation between the first filtering branch 13 and the second filtering branch 14 can be improved, and the suppression performance of the pass bands of the first filtering branch and the second filtering branch can be improved.

The housing 11 provided in this embodiment is further provided with a second port and a third port, the sixth filtering cavity a6 of the first filtering branch 13 is coupled with the second port, and the sixth filtering cavity B6 of the second filtering branch 14 is coupled with the third port. Wherein the second port and the third port can both be taps of the filter.

In the first filtering branch 13, the coupling bandwidth between the common cavity 12 and the first filtering cavity a1 ranges from 76 to 89 MHz; the coupling bandwidth between the first filter cavity a1 and the second filter cavity a2 is in the range of 59-70 MHz; the coupling bandwidth between the second filter cavity A2 and the third filter cavity A3 is in the range of 34-43 MHz; the coupling bandwidth between the second filter cavity A2 and the fourth filter cavity A4 is in the range of 20-27 MHz; the coupling bandwidth between the third filter cavity A3 and the fourth filter cavity A4 is in the range of 31-40 MHz; the coupling bandwidth between the fourth filter cavity a4 and the fifth filter cavity a5 is in the range of 34-43 MHz; the coupling bandwidth between the fourth filter cavity A4 and the sixth filter cavity A6 is in the range of 23-31 MHz; the coupling bandwidth between the fifth filter cavity A5 and the sixth filter cavity A6 is in the range of 53-63 MHz; the coupling bandwidth between the sixth filter cavity a6 and the second port is in the range of 76-89 MHz.

The resonant frequencies of the first filter cavity a1 through the sixth filter cavity a6 of the first filter branch 13 are sequentially in the following ranges: 822-, 824MHz, 841-, 843MHz, 819-, 821MHz, 846-, 848MHz, and 822-, 824 MHz.

Therefore, the bandwidth of the first filtering branch 13 of the present embodiment is located in the range of 789-863MHz, the bandwidth of the first filtering branch 13 can be accurately controlled, and the design requirement of the filter is satisfied, and in addition, the bandwidth of the first filtering branch 13 between the second filtering cavity a2 and the fourth filtering cavity a4 and the bandwidth of the first filtering branch 13 between the fourth filtering cavity a4 and the sixth filtering cavity a6 are inductively cross-coupled, respectively, so that the bandwidth of the first filtering branch 13 can be highly suppressed when the bandwidth is located in the range of 789-863 MHz.

As shown in fig. 4, fig. 4 is a schematic diagram of a simulation result of the first filtering branch provided in the present application. The simulated bandwidth of the first filtering branch 13 in this embodiment is as shown in the frequency band curve 31 in fig. 4, and it can be obtained that the simulated bandwidth of the first filtering branch 13 is within the range of 789-863MHz, which meets the design requirement of the filter and can accurately control the bandwidth of the first filtering branch 13. When the frequency range of the first filtering branch 13 is 879.5-960MHz, the suppression is more than 49 dB; when the frequency range of the first filtering branch 13 is 1710 and 2700MHz, the suppression is greater than 52 dB; the out-of-band rejection etc. of the first filter branch 13 can thus be improved.

In the second filter branch 14, the coupling bandwidth between the common cavity 12 and the first filter cavity B1 is in the range of 84-98 MHz; the coupling bandwidth between the first filter cavity B1 and the second filter cavity B2 is in the range of 58-70 MHz; the coupling bandwidth between the first filter cavity B1 and the third filter cavity B3 is in the range (-39) - (-31) MHz; the coupling bandwidth between the second filter cavity B2 and the third filter cavity B3 is in the range of 38-46 MHz; the coupling bandwidth between the third filter cavity B3 and the fourth filter cavity B4 is in the range of 41-51 MHz; the coupling bandwidth between the fourth filter cavity B4 and the fifth filter cavity B5 is in the range of 33-42 MHz; the coupling bandwidth between the fourth filter cavity B4 and the sixth filter cavity B6 ranges from (-45) - (-36)0 MHz; the coupling bandwidth between the fifth filter cavity B5 and the sixth filter cavity B6 is in the range of 54-64 MHz; the coupling bandwidth between the sixth filter cavity B6 and the third port is in the range of 84-98 MHz.

The resonant frequencies of the first filter cavity B1 through the sixth filter cavity B6 of the second filter branch 14 are in the following ranges in sequence: 919-.

Therefore, the bandwidth of the second filtering branch 14 of the present embodiment is located in the range of 879-961MHz, the bandwidth of the second filtering branch 14 can be precisely controlled, and the design requirement of the filter is satisfied, and in addition, the bandwidth of the second filtering branch 14 can be highly suppressed when the bandwidth of the second filtering branch 14 is located in the range of 879-961MHz by respectively capacitively cross-coupling between the first filtering cavity B1 and the fourth filtering cavity B3 of the second filtering branch 14 and the fourth filtering cavity B4 and the sixth filtering cavity B6 of the second filtering branch 14.

As shown in fig. 8, fig. 8 is a schematic diagram of simulation results of the second filtering branch provided in the present application. The simulated bandwidth of the second filtering branch 14 in this embodiment is as the frequency band curve 32 in fig. 8, and it can be obtained that the simulated bandwidth of the second filtering branch 14 is within the range of 879-961MHz, which meets the design requirement of the filter and can accurately control the bandwidth of the second filtering branch 14. When the frequency range of the second filtering branch circuit 14 is 790-862.5MHz, the suppression is more than 49 dB; when the frequency range of the second filtering branch 14 is 1710-2700MHz, the suppression is greater than 52 dB; the out-of-band rejection etc. of the second filter branch 14 can thus be improved.

Referring further to fig. 5, fig. 5 is a schematic structural diagram of a second embodiment of the filter provided in the present application. The filter of the present embodiment is described on the basis of the filter disclosed in the first embodiment: the filter also comprises a third filtering branch 15 and a first port, the common cavity 12 and the third filtering branch 15 are connected with the first port, the third filtering branch 15 and the second filtering branch 15 are arranged at intervals along the first direction L1, and the third filtering branch 15 and the common cavity 12 share the first port, so that the number of taps is further reduced, the welding point is reduced, the size of the filter is reduced, and the cost is reduced.

As shown in fig. 5, the third filtering branch 15 is composed of six sequentially coupled filtering cavities, the six filtering cavities of the third filtering branch 15 are a first filtering cavity C1, a second filtering cavity C2, a third filtering cavity C3, a fourth filtering cavity C4, a fifth filtering cavity C5 and a sixth filtering cavity C6, and the first filtering cavity C1 of the third filtering branch 15 is connected to the first port. The first filtering cavity C1, the second filtering cavity C2, the third filtering cavity C3, the fourth filtering cavity C4, the fifth filtering cavity C5 and the sixth filtering cavity C6 of the third filtering branch 15 are in a row and are sequentially arranged along a second direction L2; that is, the third filtering branches 15 are arranged linearly and arranged regularly, so that the space occupied by the third filtering branches 15 can be reduced, the size of the filter is reduced, and the design is easy.

As shown in fig. 6, fig. 6 is a schematic topology structure diagram of a third filtering branch provided in this application, a first filtering cavity C1, a second filtering cavity C2, a third filtering cavity C3, a fourth filtering cavity C4, a fifth filtering cavity C5, and a sixth filtering cavity C6 of the third filtering branch 15 are sequentially coupled, that is, a window (not shown) is disposed between the first filtering cavity C1 and the second filtering cavity C2 of the third filtering branch 15, a window (not shown) is disposed between the second filtering cavity C2 and the third filtering cavity C3 of the third filtering branch 15, a window (not shown) is disposed between the third filtering cavity C3 and the fourth filtering cavity C4 of the third filtering branch 15, a window (not shown) is disposed between the fourth filtering cavity C4 and the fifth filtering cavity C5 of the third filtering branch 15, and a window (not shown) is disposed between the fifth filtering cavity C5 and the sixth filtering cavity C6 of the third filtering branch 15. Therefore, the window coupling consistency of the third filtering branch 15 is good, other materials do not need to be arranged, and the cost is low.

Wherein, the housing 11 is further provided with a fourth port, and the sixth filtering cavity C6 of the third filtering branch 15 is coupled with the fourth port, and the fourth port may be a tap of the filter.

In the third filtering branch 15, the coupling bandwidth between the first port and the first filtering cavity C1 is in the range of 1051-; the coupling bandwidth range between the first filter cavity C1 and the second filter cavity C2 is 822-919 MHz; the coupling bandwidth range between the second filter cavity C2 and the third filter cavity C3 is 571 and 640 MHz; the coupling bandwidth between the third filter cavity C3 and the fourth filter cavity C4 is 541-605 MHz; the coupling bandwidth range between the fourth filter cavity C4 and the fifth filter cavity C5 is 571 and 640 MHz; the coupling bandwidth range between the fifth filter cavity C5 and the sixth filter cavity C6 is 822-919 MHz; the coupling bandwidth between the sixth filter cavity C6 and the fourth port is in the range of 1051-.

The resonant frequencies of the first filter cavity C1 through the sixth filter cavity C6 of the third filter branch 15 are sequentially in the following ranges: 2147-2149MHz, 2147-2149MHz and 2147-2149 MHz.

Therefore, the bandwidth of the third filtering branch 15 of the present embodiment is located in the range of 1707-2703MHz, and the bandwidth of the third filtering branch 15 can be accurately controlled, so as to meet the design requirement of the filter.

As shown in fig. 9, fig. 9 is a schematic diagram of a simulation result of the third filtering branch provided in the present application. The simulated bandwidth of the third filtering branch 15 in this embodiment is as the frequency band curve 33 in fig. 9, and it can be obtained that the simulated bandwidth of the third filtering branch 15 is located in the range of 1707-2703MHz, which meets the design requirement of the filter, and can accurately control the bandwidth of the third filtering branch 15. When the frequency range of the third filtering branch 15 is 790-865MHz, the suppression is greater than 52 dB; when the frequency range of the third filtering branch 15 is 880-963MHz, the suppression is greater than 50 dB; the out-of-band rejection etc. of the third filter branch 15 can thus be improved.

The present application further provides a communication device, as shown in fig. 7, fig. 7 is a schematic structural diagram of an embodiment of the communication device provided in the present application. The communication device of the present embodiment includes an antenna 62 and a radio frequency unit 61. The antenna 62 and the radio frequency unit 61 can be installed on a base station, and can also be installed on objects such as a street lamp; the antenna 62 is connected to a Radio Unit (RRU) 61. The radio frequency unit 61 comprises the filter disclosed in the above embodiments for filtering the radio frequency signal.

In other embodiments, the rf Unit 61 may be integrated with the Antenna 62 to form an Active Antenna Unit (AAU).

It should be noted that some embodiments of the present application refer to the present application as a filter, and may also be referred to as a combiner, that is, a dual-band combiner, and may also be referred to as a duplexer in other embodiments.

The above embodiments are merely examples and are not intended to limit the scope of the present disclosure, and all modifications, equivalents, and flow charts using the contents of the specification and drawings of the present disclosure or those directly or indirectly applied to other related technical fields are intended to be included in the scope of the present disclosure.

Claims

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

a common chamber disposed on the housing;

and the second filtering branch circuit is coupled with the common cavity and consists of six filtering cavities which are sequentially coupled, and the six filtering cavities of the second filtering branch circuit comprise two capacitive cross-coupling zeros.

2. The filter of claim 1,

the common cavity, the first filtering branch and the second filtering branch are divided into four rows arranged along the first direction, and a first filtering cavity of the first filtering branch and a first filtering cavity of the second filtering branch are respectively coupled with the common cavity;

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

3. The filter of claim 2,

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

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

4. The filter of claim 3,

the sixth filtering cavity of the first filtering branch is respectively intersected with the fourth filtering cavity and the fifth filtering cavity of the first filtering branch;

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

5. The filter of claim 4,

the second filtering cavity and the fourth filtering cavity of the first filtering branch circuit and the fourth filtering cavity and the sixth filtering cavity of the first filtering branch circuit are inductively cross-coupled respectively to form two inductive cross-coupling zeros of the first filtering branch circuit;

capacitive cross coupling is respectively performed between the first filtering cavity and the third filtering cavity of the second filtering branch circuit and between the fourth filtering cavity and the sixth filtering cavity of the second filtering branch circuit, so that two capacitive cross coupling zeros of the second filtering branch circuit are formed.

6. The filter of claim 5,

the bandwidth range of the first filtering branch is as follows: 789 and 863 MHz;

the bandwidth range of the second filtering branch is as follows: 879 and 961 MHz.

7. The filter according to any of claims 1-6, further comprising a third filtering branch and a first port, wherein the common cavity and the third filtering branch are connected to the first port, and wherein the third filtering branch and the second filtering branch are spaced apart along the first direction.

8. The filter of claim 7,

the third filtering branch is composed of six filtering cavities which are coupled in sequence, and a first filtering cavity, a second filtering cavity, a third filtering cavity, a fourth filtering cavity, a fifth filtering cavity and a sixth filtering cavity of the third filtering branch are in a row and are arranged in sequence in the second direction.

9. The filter of claim 8,

the bandwidth range of the third filtering branch is as follows: 1707 and 2703 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.