CN113131123A

CN113131123A - Communication device and filter

Info

Publication number: CN113131123A
Application number: CN201911399784.9A
Authority: CN
Inventors: 杨绍春; 韩军平; 马基良; 林海鑫
Original assignee: Shenzhen Tatfook Technology Co Ltd
Current assignee: Shenzhen Tatfook Technology Co Ltd
Priority date: 2019-12-30
Filing date: 2019-12-30
Publication date: 2021-07-16

Abstract

The application discloses a filter, the filter includes: the filter comprises a shell, a first filtering branch and a second filtering branch; the shell is provided with a first direction and a second direction which are perpendicular to each other; the first filtering branch is arranged on the shell and consists of seven filtering cavities which are sequentially coupled, and the seven filtering cavities of the first filtering branch form three cross-coupling zeros; the second filtering branch and the first filtering branch are arranged along the first direction and are arranged adjacently; seven filter cavities of the first filter branch are divided into two rows arranged along the first direction, and the structure of the second filter branch is the same as that of the first filter branch. Through the mode, the filter cavity can be closely arranged, design and debugging are facilitated, and the size of the filter can be reduced.

Description

Communication device and filter

Technical Field

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

Background

In a mobile communication system, a desired signal is modulated to form a modulated signal, the modulated signal is carried on a high-frequency carrier signal, the modulated signal is transmitted to the air through a transmitting antenna, the signal in the air is received through a receiving antenna, and the signal received by the receiving antenna does not include the desired signal but also includes harmonics and noise signals of other frequencies. The signal received by the receiving antenna needs to be filtered by a filter to remove unnecessary harmonic and noise signals. Therefore, the designed filter must accurately control its upper and lower limit frequencies. And should also consider maintaining high isolation between the passbands of the channels if both transmit and receive channels are present.

The inventor of the present application finds, in long-term research and development work, that the filter in the present invention may have unequal spacing distribution between the filter cavities in the filter, so that the arrangement between the filter cavities is not tight, resulting in a larger size of the whole filter.

Disclosure of Invention

The technical problem that this application mainly solved provides a communication equipment and wave filter to solve the bulky and with high costs problem of wave filter among the prior art.

In order to solve the technical problem, the application adopts a technical scheme that: providing a filter, the filter comprising: the filter includes: a housing having a first direction and a second direction perpendicular to each other; the first filtering branch is arranged on the shell and consists of seven filtering cavities which are sequentially coupled, and the seven filtering cavities of the first filtering branch form three cross-coupling zeros; the second filtering branch circuit and the first filtering branch circuit are arranged along the first direction and are arranged adjacently; seven filter cavities of the first filter branch are divided into two rows arranged along the first direction, and the structure of the second filter branch is the same as that of the first filter branch.

The first filtering cavity, the third filter, the fifth 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 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 first filtering cavity to the fifth filtering cavity of the first filtering branch are arranged in a W shape, and the fifth filtering cavity to the seventh filtering cavity of the first filtering branch are arranged in a V shape.

The second filter cavity of the first filter branch is respectively adjacent to the first filter cavity and the third filter cavity, and the first filter cavity and the third filter cavity of the second filter branch are respectively adjacent to the third filter cavity; the fourth filter cavity of the first filter branch is respectively adjacent to the third filter cavity and the fifth filter cavity as well as the third filter cavity and the fifth filter cavity of the second filter branch; and the sixth filter cavity of the first filter branch is respectively adjacent to the fifth filter cavity and the seventh filter cavity, and the fifth filter cavity and the seventh filter cavity of the second filter branch are arranged.

Inductive cross coupling is performed between a first filtering cavity and a third filtering cavity of the first filtering branch, capacitive cross coupling is performed between the third filtering cavity and a fifth filtering cavity of the first filtering branch, and between the fifth filtering cavity and a seventh filtering cavity of the first filtering branch, so that three cross coupling zeros of the first filtering branch are formed; the bandwidth of the first filtering branch circuit is located in the range of 1801-1836MHz, and the bandwidth of the second filtering branch circuit is located in the range of 1801-1836 MHz.

The filter also comprises a third filtering branch and a fourth filtering cavity which are arranged along the second direction with the first filtering branch and the second filtering branch; the projection of the third filtering branch and the fourth filtering cavity in the first direction is overlapped with the projection of the first filtering branch and the second filtering branch in the first direction.

Wherein the third filtering branch consists of five filtering cavities; the fourth filtering cavities and the first filtering cavities of the third filtering branch are in a row and are sequentially arranged along the second direction; the third filtering cavities and the second filtering cavities of the third filtering branch are in a row and are sequentially arranged along the second direction; a fifth filter cavity of the third filter branch is close to a middle branching line of the shell in the first direction relative to a fourth filter cavity, and an included angle between a connecting line of the center of the fifth filter cavity of the third filter branch and the center of the fourth filter cavity and the middle branching line is an acute angle; the first filter cavity of the third filter branch is respectively adjacent to the second filter cavity, the third filter cavity and the fourth filter cavity, and the fifth filter cavity of the third filter branch is adjacent to the fourth filter cavity.

The second filter cavity of the fourth filter branch is close to the middle branching line relative to the first filter cavity, and the second filter cavity of the fourth filter branch and the third filter cavity of the third filter branch are in a row and are sequentially arranged along the first direction; a third filter cavity of the fourth filter branch is respectively adjacent to the second filter cavity and the third filter cavity of the third filter branch; a fourth filter cavity of the fourth filter branch is far away from the midline relative to a third filter cavity, the second filter cavity to the fourth filter cavity of the fourth filter branch are arranged in a triangular shape, the projection of the third filter cavity center of the fourth filter branch in the second direction is positioned between the projection of the second filter cavity center and the projection of the fourth filter cavity center in the second direction, and the projection of the second filter cavity center of the fourth filter branch in the first direction is positioned between the projection of the third filter cavity center and the projection of the fourth filter cavity center in the first direction; a projection of the center of the third filter cavity of the fourth filter branch in the first direction is located between the center of the fifth filter cavity and a projection of the center of the fourth filter cavity of the fourth filter branch in the first direction, and a projection of the center of the fourth filter cavity of the fourth filter branch in the second direction is located between the centers of the third filter cavity and the fifth filter cavity in the second direction; a third filter cavity of the fourth filter branch is respectively adjacent to the second filter cavity, the fourth filter cavity and the third filter cavity and the fifth filter cavity of the third filter branch; the first filter cavity and the second filter cavity of the fourth filter branch are arranged adjacently; and a fourth filtering cavity of the fourth filtering branch is respectively adjacent to the third filtering cavity and the fifth filtering cavity.

The first filtering cavity and the third filtering cavity of the third filtering branch are inductively cross-coupled to form a cross-coupling zero point of the third filtering branch, and the bandwidth of the third filtering branch is located within the range of 1708-1732 MHz; the third filtering cavity and the fifth filtering cavity of the fourth filtering branch are inductively cross-coupled to form a cross-coupling zero point of the fourth filtering branch, and the bandwidth of the third filtering branch is located within the range of 1708-1732 MHz.

In order to solve the above technical problem, another technical solution adopted by the present application is: there is provided a communication device comprising the filter described above and a communication base station that transceives radio frequency signals through the filter.

The beneficial effect of this application is: different from the prior art, the filter is provided with a first filtering branch and a second filtering branch; the structure of the second filtering branch is the same as that of the first filtering branch; the filter cavities are closely arranged, so that the design and debugging are convenient, and the size of the filter can be reduced.

Drawings

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

FIG. 2 is a schematic diagram of another embodiment of the filter of the present application;

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

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

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

FIG. 6 is a schematic diagram of a topology of a fourth filtering branch of the filter shown in the present application;

FIG. 7 is a diagram showing simulation results of the filter of the present application;

fig. 8 is a schematic structural diagram of an embodiment of a communication device provided in the present application.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

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 91, as shown in fig. 1, fig. 1 is a schematic structural diagram of the first embodiment of the filter 91 of the present application.

The filter 91 of the embodiment of the present application includes a housing 10, a first filtering branch 30 and a second filtering branch 40. The first filtering branch 30 and the second filtering branch 40 may be a receiving filtering branch or a transmitting filtering branch.

The housing 10 has a first direction L and a second direction D perpendicular to each other. The first filtering branch 30 is disposed on the housing 10 and is composed of seven filtering cavities coupled in sequence, and the seven filtering cavities of the first filtering branch 30 form three cross-coupling zeros. A second filtering branch 40 arranged adjacent to the first filtering branch 30 along the first direction L; the seven filter cavities of the first filter branch 30 are divided into two rows arranged in the first direction L, and the structure of the second filter branch 40 is the same as that of the first filter branch 30.

Specifically, the first filter cavity a1, the third filter cavity A3, the fifth filter cavity a5 and the seventh filter cavity a7 of the first filter branch 30 are in a row and are sequentially arranged along the second direction D; the second filter cavity a2, the fourth filter cavity a4 and the sixth filter cavity a6 of the first filter branch 30 are in a row and are sequentially arranged along the second direction D.

The first filtering cavity B1, the third filtering cavity B3, the fifth filtering cavity B5 and the seventh filtering cavity B7 of the second filtering branch 40 are in a row and are sequentially arranged along the second direction D; the second filter cavity B2, the fourth filter cavity B4 and the sixth filter cavity B6 of the second filter branch 40 are in a row and are sequentially arranged along the second direction D.

The first filtering cavity a1 to the fifth filtering cavity a5 of the first filtering branch 30 are arranged in a W shape, and the fifth filtering cavity a5 to the seventh filtering cavity a7 of the first filtering branch 30 are arranged in a V shape.

The second filtering cavity a2 of the first filtering branch 30 is respectively adjacent to the first filtering cavity a1 and the third filtering cavity A3, and the first filtering cavity B1 and the third filtering cavity B3 of the second filtering branch 40; the fourth filtering cavity a4 of the first filtering branch 30 is respectively adjacent to the third filtering cavity A3 and the fifth filtering cavity a5, and the third filtering cavity B3 and the fifth filtering cavity B5 of the second filtering branch 40; the sixth filter cavity a6 of the first filter branch 30 is respectively disposed adjacent to the fifth filter cavity a5 and the seventh filter cavity a7, and the fifth filter cavity B5 and the seventh filter cavity B7 of the second filter branch 40. That is, the filter cavities are regularly distributed, so that the space utilization rate of the filter 91 is improved, the size of the filter 91 is reduced, and the stability of the filter 91 is improved.

Referring to fig. 1, 3 and 4, fig. 1 is a schematic structural diagram of a first embodiment of a filter 91 provided in the present application; fig. 3 is a schematic diagram of the topology of the first filtering branch 30 of the filter 91 shown in the present application; fig. 4 is a schematic diagram of the topology of the second filtering branch 40 of the filter 91 shown in the present application.

In the present embodiment, the first filter cavity a1 and the third filter cavity A3 of the first filter branch 30 are inductively cross-coupled, the third filter cavity A3 and the fifth filter cavity a5 of the first filter branch 30 are capacitively cross-coupled, and the fifth filter cavity a5 and the seventh filter cavity a7 are capacitively cross-coupled, respectively, to form three cross-coupling zeros of the first filter branch 30.

The first filter cavity B1 and the third filter cavity B3 of the second filter branch 40 are inductively cross-coupled, the third filter cavity B3 and the fifth filter cavity B5 of the second filter branch 40 are capacitively cross-coupled, and the fifth filter cavity B5 and the seventh filter cavity B7 are capacitively cross-coupled, respectively, to form three cross-coupling zeros of the second filter branch 40.

Specifically, a window may be disposed between the first filter cavity a1 and the third filter cavity A3 of the first filter branch 30, and the window is disposed with a metal coupling rib, so that the inductive cross-coupling is achieved between the first filter cavity a1 and the third filter cavity A3 of the first filter branch 30, so as to form an inductive cross-coupling zero, which is equivalent to the inductor L111 shown in fig. 3. A window may be disposed between the first filter cavity B1 and the third filter cavity B3 of the second filter branch 40, and the window is disposed with a metal coupling rib, so that an inductive cross-coupling is achieved between the first filter cavity B1 and the third filter cavity B3 of the second filter branch 40 to form an inductive cross-coupling zero, which is equivalent to the inductor L211 shown in fig. 4. In this embodiment, the inductive cross coupling is realized by the metal coupling rib, and the metal coupling rib is welded to the resonance rod in the two adjacent filter cavities, so that the cross coupling between the two adjacent filter cavities is less affected by the change of the external temperature, and therefore, the temperature drift of the filter 91 can be avoided by realizing the inductive cross coupling by the metal coupling rib.

A window may be disposed between the third filter cavity A3 and the fifth filter cavity a5 of the first filter branch 30, and a flying bar is disposed at the window, so that the third filter cavity A3 and the fifth filter cavity a5 of the first filter branch 30 implement capacitive cross coupling, and form a capacitive cross coupling zero, which is equivalent to the capacitor C111 shown in fig. 3; a window may be disposed between the fifth filter cavity a5 and the seventh filter cavity a7 of the first filter branch 30, and a flying bar may be disposed at the window, so that the fifth filter cavity a5 and the seventh filter cavity a7 of the first filter branch 30 implement capacitive cross coupling, forming a capacitive cross coupling zero, which is equivalent to the capacitor C112 shown in fig. 3. A window may be disposed between the third filter cavity B3 and the fifth filter cavity B5 of the second filter branch 40, and a flying bar is disposed at the window, so that the third filter cavity B3 and the fifth filter cavity B5 of the second filter branch 40 implement capacitive cross coupling, and form a capacitive cross coupling zero, which is equivalent to the capacitor C211 shown in fig. 4; a window may be disposed between the fifth filter cavity B5 and the seventh filter cavity B7 of the second filter branch 40, and a flying bar may be disposed at the window, so that the fifth filter cavity B5 and the seventh filter cavity B7 of the second filter branch 40 implement capacitive cross coupling, and form a capacitive cross coupling zero, which is equivalent to the capacitor C212 shown in fig. 4. In this embodiment, the capacitive cross coupling is realized through the flying bars with the same specification, so as to achieve the effect of realizing the zero point of the capacitive cross coupling, and when the filtering branch is formed, the types of materials can be reduced, the manufacturing is convenient, the complexity of the product is reduced, and the cost is saved.

Note that the coupling zero is also referred to as a transmission zero. The transmission zero is the transmission function of the filter 91 is 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.

Optionally, the housing 10 may be further provided with a first port, a second port, a third port and a fourth port. The first port is connected to the first filter cavity of the first filter branch 30, the second port is connected to the seventh filter cavity a7 of the first filter branch 30, the third port is connected to the first filter cavity B1 of the second filter branch 40, and the fourth port is connected to the seventh filter cavity B7 of the second filter branch 40. The first port, the second port, the third port and the fourth port may be taps of the filter 91.

Referring to fig. 1 and 3, fig. 1 is a schematic structural diagram of a first embodiment of a filter 91 of the present application; fig. 3 is a schematic diagram of a topology of the first filtering branch 30 of the filter 91 provided in the present application.

The first filtering branch 30 of the present embodiment may be a transmitting filtering branch. Wherein the bandwidth of the first filtering branch 30 is within the range of 1801-1836 MHz. Specifically, the coupling bandwidth between the first port and the first filter cavity a1 of the first filter branch 30 is in the range of 31MHz-39 MHz; the coupling bandwidth between the first filter cavity a1 of the first filter branch 30 and the second filter cavity a2 of the first filter branch 30 ranges from 23MHz to 30 MHz; the coupling bandwidth between the first filter cavity a1 of the first filter branch 30 and the third filter cavity A3 of the first filter branch 30 ranges from 4MHz to 9 MHz; the coupling bandwidth between the second filter cavity a2 of the first filter branch 30 and the third filter cavity A3 of the first filter branch 30 ranges from 15MHz to 21 MHz; the coupling bandwidth between the third filter cavity A3 of the first filter branch 30 and the fourth filter cavity a4 of the first filter branch 30 ranges from 15MHz to 21 MHz; the coupling bandwidth between the third filter cavity A3 of the first filter branch 30 and the fifth filter cavity a5 of the first filter branch 30 ranges from-3 MHz to 0 MHz; the coupling bandwidth between the fourth filter cavity a4 of the first filter branch 30 and the fifth filter cavity a5 of the first filter branch 30 ranges from 15MHz to 21 MHz; the coupling bandwidth between the fifth filter cavity a5 of the first filter branch 30 and the sixth filter cavity a6 of the first filter branch 30 ranges from 15MHz to 21 MHz; the coupling bandwidth between the fifth filter cavity a5 of the first filter branch 30 and the seventh filter cavity a7 of the first filter branch 30 ranges from-10 MHz to 7 MHz; the coupling bandwidth between the sixth filter cavity a6 of the first filter branch 30 and the seventh filter cavity a7 of the first filter branch 30 ranges from 23MHz to 30 MHz; the coupling bandwidth between the seventh filter cavity a7 of the first filter branch 30 and the second port is in the range of 31MHz-39 MHz. Therefore, the bandwidth of the first filtering branch 30 of the filter 91 of the present embodiment is within the range of 1801-1836MHz, which can satisfy the design requirement.

Therefore, the resonant frequencies of the first through seventh filter cavities a 1-a 7 of the first filter branch 30 lie in the following ranges: 1817MHz-1821 MHz; 1822MHz-1826 MHz; 1816MHz-1820 MHz; 1814MHz-1818 MHz; 1817MHz-1821 MHz; 1810MHz-1814 MHz; 1817MHz-1821 MHz.

Referring to fig. 1 and 4, fig. 1 is a schematic structural diagram of a first embodiment of a filter 91 of the present application; fig. 4 is a schematic diagram of the topology of the second filtering branch 40 of the filter 91 provided in the present application.

The second filtering branch 40 of the present embodiment may be a transmitting filtering branch. Wherein the bandwidth of the second filtering branch 40 is within the range of 1801-1836 MHz. Specifically, the coupling bandwidth between the first port and the first filter cavity B1 of the second filter branch 40 is in the range of 31MHz to 39 MHz; the coupling bandwidth between the first filter cavity B1 of the second filter branch 40 and the second filter cavity B2 of the second filter branch 40 ranges from 23MHz to 30 MHz; the coupling bandwidth between the first filter cavity B1 of the second filter branch 40 and the third filter cavity B3 of the second filter branch 40 ranges from 4MHz to 9 MHz; the coupling bandwidth between the second filter cavity B2 of the second filter branch 40 and the third filter cavity B3 of the second filter branch 40 ranges from 15MHz to 21 MHz; the coupling bandwidth between the third filter cavity B3 of the second filter branch 40 and the fourth filter cavity B4 of the second filter branch 40 ranges from 15MHz to 21 MHz; the coupling bandwidth between the third filter cavity B3 of the second filter branch 40 and the fifth filter cavity B5 of the second filter branch 40 ranges from-3 MHz to 0 MHz; the coupling bandwidth between the fourth filter cavity B4 of the second filter branch 40 and the fifth filter cavity B5 of the second filter branch 40 ranges from 15MHz to 21 MHz; the coupling bandwidth between the fifth filter cavity B5 of the second filter branch 40 and the sixth filter cavity B6 of the second filter branch 40 ranges from 15MHz to 21 MHz; the coupling bandwidth between the fifth filter cavity B5 of the second filter branch 40 and the seventh filter cavity B7 of the second filter branch 40 ranges from-10 MHz to 7 MHz; the coupling bandwidth between the sixth filter cavity B6 of the second filter branch 40 and the seventh filter cavity B7 of the second filter branch 40 ranges from 23MHz to 30 MHz; the coupling bandwidth between the seventh filter cavity B7 of the second filter branch 40 and the second port is in the range of 31MHz-39 MHz. Therefore, the bandwidth of the second filtering branch 40 of the filter 91 of the present embodiment is within the range of 1801-1836MHz, which can satisfy the design requirement.

Therefore, the resonant frequencies of the first through seventh filter cavities a 1-a 7 of the second filter branch 40 lie in the following ranges: 1817MHz-1821 MHz; 1822MHz-1826 MHz; 1816MHz-1820 MHz; 1814MHz-1818 MHz; 1817MHz-1821 MHz; 1810MHz-1814 MHz; 1817MHz-1821 MHz.

Example two:

fig. 2 is a schematic structural diagram of another embodiment of the filter 91 of the present application.

The filter 91 of the second embodiment further includes a third filtering branch 50 and a fourth filtering branch 60 arranged along the second direction D with the first filtering branch 30 and the second filtering branch 40. Wherein, the projections of the third filtering branch 50 and the fourth filtering branch 60 in the first direction L overlap with the projections of the first filtering branch 30 and the second filtering branch 40 in the first direction L.

Specifically, the third filtering branch 50 is composed of five filtering cavities, the fourth filtering cavity C4 and the first filtering cavity C1 of the third filtering branch 50 are in a row and are sequentially arranged along the second direction D, and the third filtering cavity C3 and the second filtering cavity C2 of the third filtering branch 50 are in a row and are sequentially arranged along the second direction D. The fifth filtering cavity C5 of the third filtering branch 50 is close to the midline of the housing 10 in the first direction L relative to the fourth filtering cavity C4, an included angle between a connecting line of the center of the fifth filtering cavity C5 of the third filtering branch 50 and the center of the fourth filtering cavity C4 and the midline is an acute angle, the first filtering cavity C1 of the third filtering branch 50 is respectively adjacent to the second filtering cavity C2, the third filtering cavity C3 and the fourth filtering cavity C4, and the fifth filtering cavity C5 of the third filtering branch 50 is adjacent to the fourth filtering cavity C4. The second filter cavity D2 of the fourth filter leg 60 is bisected closer to the first filter cavity D1.

The second filtering cavity D2 of the fourth filtering branch 60 and the third filtering cavity C3 of the third filtering branch 50 are in a row and are sequentially arranged along the first direction L, and the third filtering cavity D3 of the fourth filtering branch 60 is respectively adjacent to the second filtering cavity D2 and the third filtering cavity C3 of the third filtering branch 50. The fourth filter cavity D4 of the fourth filter branch 60 is separated from the third filter cavity D3 toward the midline, the second filter cavity D2 to the fourth filter cavity D4 of the fourth filter branch 60 are arranged in a triangle, the projection of the center of the third filter cavity D3 of the fourth filter branch 60 in the second direction D is located between the projections of the center of the second filter cavity D2 and the center of the fourth filter cavity D4 in the second direction D, and the projection of the center of the second filter cavity D2 of the fourth filter branch 60 in the first direction L is located between the projections of the center of the third filter cavity D3 and the center of the fourth filter cavity D4 in the first direction L. The third filtering cavity D3 to the fifth filtering cavity D5 of the fourth filtering branch 60 are arranged in a triangle, the projection of the center of the third filtering cavity D3 of the fourth filtering branch 60 in the first direction L is located between the projection of the center of the fifth filtering cavity D5 and the projection of the center of the fourth filtering cavity D4 in the first direction L, and the projection of the center of the fourth filtering cavity D4 of the fourth filtering branch 60 in the second direction D is located between the projection of the center of the third filtering cavity D3 and the projection of the center of the fifth filtering cavity D5 in the second direction D.

The third filtering cavity D3 of the fourth filtering branch 60 is respectively adjacent to the third filtering cavity C3 and the fifth filtering cavity C5 of the second filtering cavity D2, the fourth filtering cavity D4 and the third filtering cavity C3 of the third filtering branch 50, the first filtering cavity D1 of the fourth filtering branch 60 is adjacent to the second filtering cavity D2, and the fourth filtering cavity D4 of the fourth filtering branch 60 is adjacent to the third filtering cavity D3 and the fifth filtering cavity D5.

Referring to fig. 2, 5 and 6, fig. 2 is a schematic structural diagram of a second embodiment of the filter 91 of the present application; fig. 5 is a schematic diagram of the topology of the third filtering branch 50 of the filter 91 shown in the present application; fig. 6 is a schematic diagram of the topology of the fourth filtering branch 60 of the filter 91 shown in the present application.

In this embodiment, a window may be disposed between the first filter cavity C1 and the third filter cavity C3 of the third filter branch 50, and a metal coupling rib is disposed on the window, so that the inductive cross-coupling is achieved between the first filter cavity C1 and the third filter cavity C3 of the third filter branch 50, so as to form an inductive cross-coupling zero, which is equivalent to the inductor L311 shown in fig. 5. A window may be disposed between the third filter cavity D3 and the fifth filter cavity D5 of the fourth filter branch 60, and a metal coupling rib is disposed on the window, so that the inductive cross-coupling is achieved between the third filter cavity D3 and the fifth filter cavity D5 of the fourth filter branch 60, so as to form an inductive cross-coupling zero, which is equivalent to the inductor L411 shown in fig. 6. In this embodiment, the inductive cross coupling is realized by the metal coupling rib, and the metal coupling rib is welded to the resonance rod in the two adjacent filter cavities, so that the cross coupling between the two adjacent filter cavities is less affected by the change of the external temperature, and therefore, the temperature drift of the filter 91 can be avoided by realizing the inductive cross coupling by the metal coupling rib.

Optionally, the housing 10 may be further provided with a first port, a second port, a third port, a fourth port, a fifth port and a sixth port. The first port is connected to the first filter cavity a1 of the first filter branch 30 and the first filter cavity C1 of the third filter branch 50, the second port is connected to the seventh filter cavity a7 of the first filter branch 30, the third port is connected to the first filter cavity B1 of the second filter branch 40 and the first filter cavity D1 of the fourth filter branch 60, the fourth port is connected to the seventh filter cavity B7 of the second filter branch 40, the fifth port is connected to the fifth filter cavity C5 of the third filter branch 50, and the sixth port is connected to the fifth filter cavity D5 of the fourth filter branch 60. Wherein the first port, the second port, the third port, the fourth port, the fifth port and the sixth port may be taps of the filter 91.

Referring to fig. 2 and 5, fig. 2 is a schematic structural diagram of a second embodiment of the filter 91 provided in the present application; fig. 5 is a schematic diagram of a topology of the third filtering branch 50 of the filter 91 provided in the present application.

The third filtering branch 50 of the present embodiment may be a transmitting filtering branch. Wherein the bandwidth of the third filtering branch 50 is within the range of 1708-1732 MHz. Specifically, the coupling bandwidth between the first port and the first filtering cavity C1 of the third filtering branch 50 is in the range of 23MHz to 30 MHz; the coupling bandwidth between the first filter cavity C1 of the third filter branch 50 and the second filter cavity C2 of the third filter branch 50 ranges from 17MHz to 24 MHz; the coupling bandwidth between the first filter cavity C1 of the third filter branch 50 and the third filter cavity C3 of the third filter branch 50 ranges from 5MHz to 10 MHz; the coupling bandwidth between the second filter cavity C2 of the third filter branch 50 and the third filter cavity C3 of the third filter branch 50 ranges from 11MHz to 17 MHz; the coupling bandwidth between the third filter cavity C3 of the third filter branch 50 and the fourth filter cavity C4 of the third filter branch 50 ranges from 13MHz to 19 MHz; the coupling bandwidth between the fourth filter cavity C4 of the third filter branch 50 and the fifth filter cavity C5 of the third filter branch 50 ranges from 18MHz to 25 MHz; the coupling bandwidth between the fifth filter cavity C5 and the fifth port of the third filter branch 50 is in the range of 23MHz-30 MHz. Therefore, the bandwidth of the third filtering branch 50 of the filter 91 of the present embodiment is within the range of 1708-1732MHz, which can satisfy the design requirement.

Therefore, the resonant frequencies of the first through fifth filter cavities C1-C5 of the third filter branch 50 lie in the following ranges: 1720MHz-1724 MHz; 1725MHz-1729 MHz; 1719MHz-1723 MHz; 1720MHz-1724 MHz; 1720MHz-1724 MHz.

Referring to fig. 2 and fig. 6, fig. 2 is a schematic structural diagram of a second embodiment of the filter 91 provided in the present application; fig. 6 is a schematic diagram of a topology of a fourth filtering branch 60 of a filter 91 provided in the present application.

The fourth filtering branch 60 of the present embodiment may be a transmit filtering branch. Wherein the bandwidth of the fourth filtering branch 60 is within the range of 1708-1732 MHz. Specifically, the coupling bandwidth between the third port and the first filter cavity D1 of the fourth filter branch 60 is in the range of 23MHz to 30 MHz; the coupling bandwidth between the first filter cavity D1 of the fourth filter branch 60 and the second filter cavity D2 of the fourth filter branch 60 ranges from 18MHz to 25 MHz; the coupling bandwidth between the second filter cavity D2 of the fourth filter branch 60 and the third filter cavity D3 of the fourth filter branch 60 ranges from 13MHz to 19 MHz; the coupling bandwidth between the third filter cavity D3 of the fourth filter branch 60 and the fourth filter cavity D4 of the fourth filter branch 60 ranges from 11MHz to 17 MHz; the coupling bandwidth between the third filter cavity D3 of the fourth filter branch 60 and the fifth filter cavity D5 of the fourth filter branch 60 ranges from 5MHz to 10 MHz; the coupling bandwidth between the fourth filter cavity D4 of the fourth filter branch 60 and the fifth filter cavity D5 of the fourth filter branch 60 ranges from 17MHz to 24 MHz; the coupling bandwidth between the fifth filter cavity D5 and the sixth port of the fourth filter branch 60 is in the range of 23MHz-30 MHz. Therefore, the bandwidth of the fourth filtering branch 60 of the filter 91 of the present embodiment is within the range of 1708-1732MHz, which can meet the design requirement.

Therefore, the resonant frequencies of the first filter cavity D1 through the fifth filter cavity of the fourth filter branch 60 are in the following ranges: 1720MHz-1724 MHz; 1725MHz-1729 MHz; 1719MHz-1723 MHz; 1725MHz-1729 MHz; 1720MHz-1724 MHz.

Referring to fig. 7, fig. 7 is a diagram showing simulation results of the filter 91. Through experimental tests, the bandwidths of the first filtering branch 30 and the second filtering branch 40 of the filter 91 of the present application are located at 1801-1836MHz, as shown by the frequency band curve 110 in fig. 7. Wherein the bandwidth rejection is greater than 105dB at 1735MHz in the graph; wherein the bandwidth rejection is greater than 75dB for a frequency of 1785MHz in the figure; where the bandwidth rejection is greater than 75dB for a frequency of 1880MHz in the figure. Therefore, the performance of the filter 91, such as out-of-band rejection, can be improved.

The bandwidths of the third filtering branch 50 and the fourth filtering branch 60 are located at 1708-1732MHz, as shown by the frequency band curve 100 in fig. 7. Wherein the bandwidth rejection is greater than 10dB for a frequency of 1700MHz in the figure; wherein the bandwidth rejection is greater than 30dB for a 1755MHz frequency in the figure; where the bandwidth rejection is greater than 80dB for a frequency of 1805MHz in the figure. Therefore, the performance of the filter 91, 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. 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.

The present application further provides a communication device 90, as shown in fig. 8, fig. 8 is a schematic structural diagram of an embodiment of the communication device 90 of the present application. The communication device 90 of this embodiment includes an antenna 93 and a Radio frequency Unit (RRU), and the RRU further includes a filter 91 for filtering a Radio frequency signal. In other embodiments, the rf Unit may be integrally designed with the Antenna 93 to form an Active Antenna Unit (AAU) 93, wherein the filter 91 may be the above-mentioned filter 91, and will not be described herein again.

The above description is only an embodiment of the present invention, and not intended to limit the scope of the present invention, and all modifications of equivalent structures and equivalent processes performed by the present specification and drawings, or directly or indirectly applied to other related technical fields, are included in the scope of the present invention.

Claims

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

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

the first filtering branch is arranged on the shell and consists of seven filtering cavities which are sequentially coupled, and the seven filtering cavities of the first filtering branch form three cross-coupling zeros;

the second filtering branch circuit and the first filtering branch circuit are arranged along the first direction and are arranged adjacently;

seven filter cavities of the first filter branch are divided into two rows arranged along the first direction, and the structure of the second filter branch is the same as that of the first filter branch.

2. The filter of claim 1,

the first filtering cavity, the third filtering cavity, the fifth 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 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.

3. The filter of claim 2,

4. The filter of claim 3,

the second filter cavity of the first filter branch is respectively adjacent to the first filter cavity and the third filter cavity as well as the first filter cavity and the third filter cavity of the second filter branch;

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

and the sixth filter cavity of the first filter branch is respectively adjacent to the fifth filter cavity and the seventh filter cavity, and the fifth filter cavity and the seventh filter cavity of the second filter branch are arranged.

5. The filter according to claim 3, wherein the first filter cavity and the third filter cavity of the first filter branch are inductively cross-coupled, and the third filter cavity and the fifth filter cavity of the first filter branch are capacitively cross-coupled, respectively, with the seventh filter cavity, to form three cross-coupling zeros of the first filter branch;

the bandwidth of the first filtering branch circuit is located in the range of 1801-1836MHz, and the bandwidth of the second filtering branch circuit is located in the range of 1801-1836 MHz.

6. The filter according to any of claims 1-5, further comprising a third filtering branch and a fourth filtering branch, aligned with the first filtering branch and the second filtering branch along the second direction;

the projection of the third filtering branch and the fourth filtering branch in the first direction is overlapped with the projection of the first filtering branch and the second filtering branch in the first direction.

7. The filter of claim 6,

the third filtering branch consists of five filtering cavities;

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

the third filtering cavities and the second filtering cavities of the third filtering branch are in a row and are sequentially arranged along the second direction;

a fifth filter cavity of the third filter branch is close to a middle branching line of the shell in the first direction relative to a fourth filter cavity, and an included angle between a connecting line of the center of the fifth filter cavity of the third filter branch and the center of the fourth filter cavity and the middle branching line is an acute angle;

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

8. The filter of claim 7,

the second filter cavity of the fourth filter branch is close to the middle branching line relative to the first filter cavity, and the second filter cavity of the fourth filter branch and the third filter cavity of the third filter branch are in a row and are sequentially arranged along the first direction;

a third filter cavity of the fourth filter branch is respectively adjacent to the second filter cavity and the third filter cavity of the third filter branch;

a fourth filter cavity of the fourth filter branch is far away from the midline relative to a third filter cavity, the second filter cavity to the fourth filter cavity of the fourth filter branch are arranged in a triangular shape, the projection of the third filter cavity center of the fourth filter branch in the second direction is positioned between the projection of the second filter cavity center and the projection of the fourth filter cavity center in the second direction, and the projection of the second filter cavity center of the fourth filter branch in the first direction is positioned between the projection of the third filter cavity center and the projection of the fourth filter cavity center in the first direction;

a projection of the center of the third filter cavity of the fourth filter branch in the first direction is located between the center of the fifth filter cavity and a projection of the center of the fourth filter cavity of the fourth filter branch in the first direction, and a projection of the center of the fourth filter cavity of the fourth filter branch in the second direction is located between the centers of the third filter cavity and the fifth filter cavity in the second direction;

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

the first filter cavity and the second filter cavity of the fourth filter branch are arranged adjacently;

and a fourth filtering cavity of the fourth filtering branch is respectively adjacent to the third filtering cavity and the fifth filtering cavity.

9. The filter of claim 8,

the first filtering cavity and the third filtering cavity of the third filtering branch are inductively cross-coupled to form a cross-coupling zero point of the third filtering branch, and the bandwidth of the third filtering branch is within the range of 1708-1732 MHz;

the third filtering cavity and the fifth filtering cavity of the fourth filtering branch are inductively cross-coupled to form a cross-coupling zero point of the fourth filtering branch, and the bandwidth of the third filtering branch is located within the range of 1708-1732 MHz.

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