CN211125969U

CN211125969U - Filter and communication equipment

Info

Publication number: CN211125969U
Application number: CN201922391479.7U
Authority: CN
Inventors: 韩军平; 蔡永宏; 何慧华; 张宝真
Original assignee: Shenzhen Tatfook Technology Co Ltd
Current assignee: Anhui Tatfook Technology Co Ltd
Priority date: 2019-12-25
Filing date: 2019-12-25
Publication date: 2020-07-28
Anticipated expiration: 2029-12-25

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; the first filtering branch is arranged on the first surface of the shell and consists of eight filtering cavities which are sequentially coupled, and the eight filtering cavities of the first filtering branch form four cross-coupling zeros; and the second filtering branch circuit is arranged on the second surface of the shell and consists of seven filtering cavities which are sequentially coupled, and the seven filtering cavities of the second filtering branch circuit form three cross-coupling zeros. In this way, the first surface and the second surface of the shell are provided with the filtering branches, so that the size of the filter can be 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 at least first filtering branch road and second filtering branch road among the prior art, and first filtering branch road and second filtering branch road all set up on the same surface of wave filter casing, lead to the bulky of wave filter.

SUMMERY OF THE UTILITY MODEL

The application provides a filter and communication equipment to solve the technical problem that the filter is large in size 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;

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

and the second filtering branch circuit is arranged on the second surface of the shell and consists of seven filtering cavities which are sequentially coupled, and the seven filtering cavities of the second filtering branch circuit form three cross-coupling zeros.

Wherein the eight filter cavities of the first filter branch are divided into three rows arranged along the first direction;

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

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

the seventh filtering cavities of the first filtering branch are in a row;

and the first filtering cavity and the third filtering cavity, the first filtering cavity and the fourth filtering cavity and the fifth filtering cavity and the eighth filtering cavity of the first filtering branch are inductively and cross-coupled, and the sixth filtering cavity and the eighth filtering cavity of the first filtering branch are capacitively and cross-coupled to form four cross-coupling zeros of the first filtering branch.

The first filtering cavity of the first filtering branch is respectively adjacent to the second filtering cavity, the third filtering cavity and the fourth filtering cavity;

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

Wherein the seven filter cavities of the second filter branch are divided into three columns arranged along the first direction;

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

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

the sixth filtering cavities of the second filtering branch are in a row;

and the first filtering cavity and the third filtering cavity of the second filtering branch circuit and the fifth filtering cavity and the seventh filtering cavity of the second filtering branch circuit are in inductive cross coupling respectively, and the third filtering cavity and the fifth filtering cavity of the second filtering branch circuit are in capacitive cross coupling so as to form three cross coupling zeros of the second filtering branch circuit.

And the fifth filtering cavity of the second filtering branch is respectively adjacent to the first filtering cavity, the third filtering cavity, the fourth filtering cavity, the sixth filtering cavity and the seventh filtering cavity.

Wherein the filter comprises:

the third filtering branch is arranged on the first surface and consists of eight filtering cavities which are sequentially coupled, and the eight filtering cavities of the third filtering branch form four cross-coupling zero points;

and the fourth filtering branch is arranged on the second surface and consists of seven filtering cavities which are sequentially coupled, and the seven filtering cavities of the second filtering branch form three cross-coupling zeros.

The third filtering branch and the first filtering branch are divided into five columns arranged along the first direction;

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

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

the second filtering cavity and the third filtering cavity of the third filtering branch circuit and the seventh filtering cavity of the first filtering branch circuit are in a row and are arranged along the second direction;

the fourth filtering branch and the second filtering branch are divided into five columns arranged along the first direction;

the second filter cavity, the first filter cavity and the seventh filter cavity of the fourth filter branch are in a row and are arranged along the second direction;

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

and the fourth filter cavities of the fourth filter branch and the sixth filter cavities of the second filter branch are in a row and are arranged along the second direction.

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

a sixth filter cavity and a fourth filter cavity of the third filter branch are arranged adjacently;

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

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

Wherein, the bandwidth range of the first filtering branch circuit is: 1851-;

the bandwidth range of the second filtering branch is as follows: 1749 and 1793 MHz;

the bandwidth range of the third filtering branch is as follows: 1851-;

the bandwidth range of the fourth filtering branch is as follows: 1749 and 1793 MHz.

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, the first filtering branch road of this application sets up on the first surface of casing, and the second filtering branch road sets up on the second surface of casing, and the first surface of casing and second surface all are provided with the filtering branch road promptly, can reduce the volume of wave filter, reduce cost.

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 first filtering branch of a filter provided in the present application;

fig. 2 is a schematic structural diagram of a first embodiment of a second filtering branch of the filter provided by the present application;

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

FIG. 4 is a diagram illustrating simulation results of a filter provided herein;

FIG. 5 is a schematic diagram of the topology of the second filtering branch of FIG. 2;

FIG. 6 is a diagram illustrating simulation results of a filter provided herein;

fig. 7 is a schematic structural diagram of a second embodiment of a first filtering branch of a filter provided by the present application;

fig. 8 is a schematic structural diagram of a second embodiment of a second filtering branch of the filter provided in the present application;

fig. 9 is a schematic structural diagram of a first embodiment of a third filtering branch of the filter provided by the present application;

fig. 10 is a schematic structural diagram of a first embodiment of a fourth filtering branch of the filter provided in the present application;

FIG. 11 is a schematic diagram of the topology of the third filtering branch of FIG. 9;

FIG. 12 is a schematic of the topology of the fourth filtering branch of FIG. 10;

fig. 13 is a schematic structural diagram of a second embodiment of a third filtering branch of the filter provided in the present application;

fig. 14 is a schematic structural diagram of a second embodiment of a fourth filtering branch of the filter provided in the present application;

fig. 15 is a schematic structural diagram of an embodiment of a communication device 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. 1-2, fig. 1 is a schematic structural diagram of a first embodiment of a first filtering branch of a filter provided by the present application, and fig. 2 is a schematic structural diagram of a first embodiment of a second filtering branch of a filter provided by the present application, the filter of the present embodiment includes a housing, a first filtering branch 12 and a second filtering branch 13, the housing 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, the second direction L2 may be a width direction of the housing, the housing includes a first surface 111 and a second surface 112, and the first surface 111 and the second surface 112 are disposed opposite to each other.

As shown in fig. 1, the first filtering branch 12 is disposed on the first surface 111 of the housing and is composed of eight filtering cavities coupled in sequence, and the eight filtering cavities of the first filtering branch 12 form four cross-coupling zeros; the eight filter cavities of the first filter branch 12 are a first filter cavity a1, a second filter cavity a2, a third filter cavity A3, a fourth filter cavity a4, a fifth filter cavity a5, a sixth filter cavity a6, a seventh filter cavity a7 and an eighth filter cavity A8 of the first filter branch 12.

As shown in fig. 2, the second filtering branch 13 is disposed on the second surface 112 of the housing and is composed of seven filtering cavities coupled in sequence, and the seven filtering cavities of the second filtering branch 13 form three cross-coupling zeros; the seven filter cavities of the second filter branch 13 are a first filter cavity B1, a second filter cavity B2, a third filter cavity B3, a fourth filter cavity B4, a fifth filter cavity B5, a sixth filter cavity B6 and a seventh filter cavity B7 of the second filter branch 13.

The first filtering branch 12 is disposed on the first surface 111 of the housing, and the second filtering branch 13 is disposed on the second surface 112 of the housing, that is, the first surface 111 and the second surface 112 of the housing are both provided with filtering branches, so as to reduce the length or width of the housing, reduce the size of the filter, and reduce the cost.

As shown in fig. 1, the eight filter cavities of the first filter branch 12 are divided into three rows arranged along the first direction L1, the first filter cavity a1, the fourth filter cavity A4 and the fifth filter cavity A5 of the first filter branch 12 are arranged in a row and arranged along the second direction L, the second filter cavity a2, the third filter cavity A3, the sixth filter cavity A6 and the eighth filter cavity a 539a 7 of the first filter branch 12 are arranged in a row and arranged along the second direction 632, and the seventh filter cavity L of the first filter branch 12 is arranged in a row, so that the eight filter cavities of the first filter branch 12 are regularly arranged in the three rows for design convenience, and the volume of the filter is reduced.

As shown in fig. 1 and 3, fig. 3 is a schematic diagram of the topology of the first filtering branch in fig. 1. Inductive cross coupling is respectively performed between the first filter cavity a1 and the third filter cavity A3, between the first filter cavity a and the fourth filter cavity a4, and between the fifth filter cavity a5 and the eighth filter cavity A8 of the first filter branch 12, and capacitive cross coupling is performed between the sixth filter cavity a6 and the eighth filter cavity A8 of the first filter branch 12, so as to form four cross-coupling zeros of the first filter branch 12. Typically, the inductive cross-coupling element may be a metal rib, i.e. a metal rib is arranged between the first filter cavity a1 and the third filter cavity A3. Typically the capacitive cross-coupling element may be a flying rod, i.e. a flying rod is arranged between the sixth filter cavity a6 and the eighth filter cavity A8. The first filtering branch 12 realizes zero suppression by setting four cross-coupling zeros, so that the first filtering branch 12 meets design requirements, and debugging is facilitated.

The first filtering cavity a1 to the sixth filtering cavity a6 of the first filtering branch 12 are arranged in a 5-shape, and the sixth filtering cavity a6 to the eighth filtering cavity A8 of the first filtering branch 12 are arranged in a V-shape, so that the eight filtering cavities of the first filtering branch 12 are compactly arranged, and the size of the filter is reduced.

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.

In the first filtering branch 12, the coupling bandwidth between the first filtering cavity a1 and the second filtering cavity a2 is in the range of 8-14 MHz; the bandwidth of the coupling between the first filter cavity a1 and the third filter cavity A3 is in the range of (-21) - (-14) MHz; the coupling bandwidth between the first filter cavity A1 and the fourth filter cavity A4 is in the range of 3-8 MHz; the coupling bandwidth between the second filter cavity A2 and the third filter cavity A3 is in the range of 2-7 MHz; the coupling bandwidth between the third filter cavity A3 and the fourth filter cavity A4 is in the range of 11-17 MHz; the coupling bandwidth between the fourth filter cavity A4 and the fifth filter cavity A5 is in the range of 11-17 MHz; the coupling bandwidth between the fifth filter cavity A5 and the sixth filter cavity A6 is in the range of 11-17 MHz; the coupling bandwidth between the fifth filter cavity A5 and the eighth filter cavity A8 is in the range of 1-6 MHz; the coupling bandwidth between the sixth filter cavity A6 and the seventh filter cavity A7 is in the range of 5-10 MHz; the coupling bandwidth between the sixth filter cavity A6 and the eighth filter cavity A8 is in the range of 12-18 MHz; the coupling bandwidth between the seventh filter cavity a7 and the eighth filter cavity A8 is in the range of 12-18 MHz.

The resonant frequencies of the first filter cavity a1 through the eighth filter cavity A8 of the first filter branch 12 are sequentially in the following ranges: 1864-1866MHz, 1852-1854MHz, 1862-1864MHz, 1865-1867MHz, 1864-1866MHz, 1865-1867MHz, 1875-1877MHz and 1866-1867 MHz. Therefore, the bandwidth of the first filtering branch 12 of this embodiment is located in the range of 1851-1880MHz, which can accurately control the bandwidth of the first filtering branch 12 to meet the design requirement of the filter.

As shown in fig. 4, fig. 4 is a schematic diagram of simulation results of the filter provided in the present application. The simulated bandwidth of the first filtering branch 12 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 12 is located in the range of 1851-1880MHz, which meets the design requirement of the filter, and can accurately control the bandwidth of the first filtering branch 12. When the frequency range of the first filtering branch 12 is 0-1786MHz, the suppression is more than or equal to 91 dB; the first filtering branch 12 suppresses more than or equal to 28dB in the frequency range of 1785-1851 MHz; when the frequency range of the first filtering branch 12 is 1884-1900MHz, the suppression is greater than or equal to 53 dB; the first filtering branch 12 suppresses more than or equal to 68dB in the frequency band range of 1899-1920 MHz; the first filtering branch 12 suppresses more than or equal to 73dB in the frequency range of 1919-3700 MHz; the out-of-band rejection etc. of the first filtering branch 12 can thus be improved.

As shown in fig. 2, the seven filter cavities of the second filter branch 13 are divided into three rows arranged along the first direction L1, the second filter cavity B2, the third filter cavity B3 and the fourth filter cavity B4 of the second filter branch 13 are arranged in one row and arranged along the second direction L2, the first filter cavity B1, the fifth filter cavity B5 and the seventh filter cavity B7 of the second filter branch 13 are arranged in one row and arranged along the second direction L2, the sixth filter cavity B6 of the second filter branch 13 is arranged in one row, so that the seven filter cavities of the second filter branch 13 are regularly arranged in three rows for design and reduction of the volume of the filter, the seven filter cavities of the second filter branch 13 of the present embodiment are arranged at a sub-interval, and the intervals of the two filter cavities coupled in sequence are equal, for example, the interval between the sixth filter cavity B6 and the seventh filter cavity B7 is equal to the interval between the first filter cavity B1 and the second filter cavity B2.

As shown in fig. 2 and 5, fig. 5 is a schematic diagram of the topology of the second filtering branch in fig. 2. Inductive cross coupling is respectively performed between the first filtering cavity B1 and the third filtering cavity B3 of the second filtering branch 13 and between the fifth filtering cavity B5 and the seventh filtering cavity B7, and the third filtering cavity B3 and the fifth filtering cavity B5 of the second filtering branch 13 are capacitively cross-coupled to form three cross-coupling zeros of the second filtering branch 13. The second filtering branch 13 realizes zero suppression by setting three cross-coupling zeros, so that the second filtering branch 13 meets the design requirement, and is convenient to debug.

The first filtering cavity B1 to the third filtering cavity B3 of the second filtering branch 13 are arranged in a V shape, and the third filtering cavity B3 to the seventh filtering cavity B7 of the second filtering branch 13 are arranged in an M shape, so that the seven filtering cavities of the second filtering branch 13 are compactly arranged, and the size of the filter is reduced.

In the second filtering branch 13, the coupling bandwidth between the first filtering cavity B1 and the second filtering cavity B2 is in the range of 30-38 MHz; the coupling bandwidth between the first filter cavity B1 and the third filter cavity B3 is in the range of 2-7 MHz; the coupling bandwidth between the second filter cavity B2 and the third filter cavity B3 is in the range of 20-27 MHz; the coupling bandwidth between the third filter cavity B3 and the fourth filter cavity B4 is in the range of 14-20 MHz; the bandwidth of the coupling between the third filter cavity B3 and the fifth filter cavity B5 is in the range of (-17) - (-11) MHz; the coupling bandwidth between the fourth filter cavity B4 and the fifth filter cavity B5 is in the range of 14-21 MHz; the coupling bandwidth between the fifth filter cavity B5 and the sixth filter cavity B6 is in the range of 15-22 MHz; the coupling bandwidth between the fifth filter cavity B5 and the seventh filter cavity B7 is in the range of 16-22 MHz; the coupling bandwidth between the sixth filter cavity B6 and the seventh filter cavity B7 is in the range of 25-33 MHz.

The resonant frequencies of the first filter cavity B1 through the seventh filter cavity B7 of the second filter branch 13 are sequentially in the following ranges: 1769-1771MHz, 1773-1775MHz, 1769-1771MHz, 1755-1757MHz, 1768-1770MHz, 1783-1785MHz and 1769-1771 MHz. Therefore, the bandwidth of the second filtering branch 13 of the present embodiment is located in the range of 1749-1793MHz, and the bandwidth of the second filtering branch 13 can be accurately controlled, so as to meet the design requirement of the filter.

As shown in fig. 6, fig. 6 is a schematic diagram of simulation results of the filter provided in the present application. The simulated bandwidth of the second filtering branch 13 in this embodiment is as shown in the frequency band curve 32 in fig. 6, and it can be obtained that the simulated bandwidth of the second filtering branch 13 is located in the range of 1749-1793MHz, which meets the design requirement of the filter and can accurately control the bandwidth of the second filtering branch 13. The second filtering branch 13 suppresses more than or equal to 83dB in the frequency range of 1500-1576 MHz; the second filtering branch 13 suppresses more than or equal to 71dB in the frequency range of 1575-1616 MHz; the second filtering branch 13 suppresses more than or equal to 37dB in the frequency band range of 1665-1679 MHz; when the frequency band range of the second filtering branch 13 is 1678-1746MHz, the suppression is greater than or equal to 28 dB; when the frequency band range of the second filtering branch 13 is 1799 and 1860MHz, the suppression is greater than or equal to 38 dB; the second filtering branch 13 suppresses more than or equal to 78dB in the frequency range of 1859-1880 MHz; when the frequency range of the second filtering branch 13 is 1879-2690MHz, the suppression is greater than or equal to 93 dB; the out-of-band rejection etc. of the second filter branch 13 can thus be improved.

As shown in fig. 7-8, fig. 7 is a schematic structural diagram of a second embodiment of a first filtering branch of the filter provided by the present application; fig. 8 is a schematic structural diagram of a second embodiment of a second filtering branch of the filter provided in the present application. The filter of the present embodiment is different from the filter of the first embodiment in that:

the first filtering cavity a1 of the first filtering branch 12 is respectively adjacent to the second filtering cavity a2, the third filtering cavity A3 and the fourth filtering cavity a 4; the sixth filtering cavity a6 of the first filtering branch 12 is respectively adjacent to the third filtering cavity A3, the fourth filtering cavity a4, the fifth filtering cavity a5, the eighth filtering cavity A8 and the seventh filtering cavity a 7; the fifth filtering cavity B5 of the second filtering branch 13 is respectively adjacent to the first filtering cavity B1, the third filtering cavity B3, the fourth filtering cavity B4, the sixth filtering cavity B6 and the seventh filtering cavity B7. Compared with the filter of the first embodiment, the filter of the present embodiment has a plurality of filter cavities arranged closely, and the volume of the filter can be reduced.

As shown in fig. 9-10, fig. 9 is a schematic structural diagram of a first embodiment of a third filtering branch of the filter provided by the present application; fig. 10 is a schematic structural diagram of a first embodiment of a fourth filtering branch of the filter provided by the present application. The filter of this embodiment is described on the basis of the filter of the first embodiment, and the filter further includes a third filtering branch 14 and a fourth filtering branch 15.

As shown in fig. 9, the third filtering branch 14 is disposed on the first surface 111 and is composed of eight filtering cavities coupled in sequence, and the eight filtering cavities of the third filtering branch 14 form four cross-coupling zeros; the eight filter cavities of the third filter branch 14 are a first filter cavity C1, a second filter cavity C2, a third filter cavity C3, a fourth filter cavity C4, a fifth filter cavity C5, a sixth filter cavity C6, a seventh filter cavity C7 and an eighth filter cavity C8 of the third filter branch 14.

The third filtering branch 14 and the first filtering branch 12 are divided into five rows arranged along a first direction L1, the sixth filtering cavity C6 and the seventh filtering cavity C7 of the third filtering branch 14 are one row and arranged along a second direction L2, the first filtering cavity C1, the fourth filtering cavity C4, the fifth filtering cavity C5 and the eighth filtering cavity C8 of the third filtering branch 14 are one row and arranged along the second direction L2, the second filtering cavity C2 and the third filtering cavity C3 of the third filtering branch 14 and the seventh filtering cavity a7 of the first filtering branch 12 are one row and arranged along the second direction L2, so that the third filtering branch 14 and the first filtering branch 12 are regularly divided into five rows.

As shown in fig. 9 and 11, fig. 11 is a schematic diagram of the topology of the third filtering branch in fig. 9. Inductive cross coupling is respectively performed between the first filtering cavity C1 and the fourth filtering cavity C4, between the second filtering cavity C2 and the fourth filtering cavity C4, and between the fifth filtering cavity C5 and the eighth filtering cavity C8 of the third filtering branch 14, and capacitive cross coupling is performed between the fifth filtering cavity C5 and the seventh filtering cavity C7 of the third filtering branch 14, so as to form four cross-coupling zeros of the third filtering branch 14. The third filtering branch 14 realizes zero suppression by setting four cross-coupling zeros, so that the third filtering branch 14 meets design requirements, and is convenient to debug.

The first filtering cavity C1 to the fourth filtering cavity C4 of the third filtering branch 14 are arranged in a U shape, and the third filtering cavity C3 to the eighth filtering cavity C8 of the third filtering branch 14 are arranged in a3 shape, so that the eight filtering cavities of the third filtering branch 14 are compactly arranged, and the size of the filter is reduced.

In the third filtering branch 14, the coupling bandwidth between the first filtering cavity C1 and the second filtering cavity C2 is in the range of 17-24 MHz; the coupling bandwidth between the first filter cavity C1 and the fourth filter cavity C4 is in the range of 3-8 MHz; the coupling bandwidth between the second filter cavity C2 and the third filter cavity C3 is in the range of 4-9 MHz; the coupling bandwidth between the second filter cavity C2 and the fourth filter cavity C4 ranges from (-15) - (-9) MHz; the coupling bandwidth between the third filter cavity C3 and the fourth filter cavity C4 ranges from 4MHz to 10 MHz; the coupling bandwidth between the fourth filter cavity C4 and the fifth filter cavity C5 is in the range of 11-17 MHz; the coupling bandwidth between the fifth filter cavity C5 and the sixth filter cavity C6 is in the range of 7-13 MHz; the coupling bandwidth between the fifth filter cavity C5 and the seventh filter cavity C7 is in the range of 7-13 MHz; the coupling bandwidth between the fifth filter cavity C5 and the eighth filter cavity C8 is in the range of 1-6 MHz; the coupling bandwidth between the sixth filter cavity C6 and the seventh filter cavity C7 is in the range of 7-13 MHz; the coupling bandwidth between the seventh filter cavity C7 and the eighth filter cavity C8 is in the range of 18-25 MHz.

The resonant frequencies of the first filter cavity C1 through the eighth filter cavity C8 of the third filter branch 14 are sequentially in the following ranges: 1864-1866MHz, 1861-1863MHz, 1852-1854MHz, 1865-1867MHz, 1864-1866MHz, 1874-1876MHz, 1866-1868MHz and 1864-1868 MHz. Therefore, the bandwidth of the third filtering branch 14 of this embodiment is located in the range of 1851-1880MHz, and the bandwidth of the third filtering branch 14 can be accurately controlled, so as to meet the design requirement of the filter.

As shown in fig. 4, fig. 4 is a schematic diagram of simulation results of the filter provided in the present application. The simulated bandwidth of the third filtering branch 14 in this embodiment is as the band curve 31 in fig. 4, and it can be obtained that the simulated bandwidth of the third filtering branch 14 is located in the range of 1851-1880MHz, which meets the design requirement of the filter and can accurately control the bandwidth of the third filtering branch 14. When the frequency range of the third filtering branch 14 is 0-1786MHz, the suppression is more than or equal to 91 dB; the third filtering branch 14 suppresses more than or equal to 28dB in the frequency range of 1785-1851 MHz; when the frequency range of the third filtering branch 14 is 1884-1900MHz, the suppression is greater than or equal to 53 dB; the third filtering branch 14 suppresses more than or equal to 68dB in the frequency band range of 1899-1920 MHz; the third filtering branch 14 suppresses more than or equal to 73dB in the frequency range of 1919-3700 MHz; the out-of-band rejection etc. of the third filter branch 14 can be improved.

As shown in fig. 10, the fourth filtering branch 15 is disposed on the second surface 112 and is composed of seven filtering cavities coupled in sequence, and the seven filtering cavities of the fourth filtering branch 15 form three cross-coupling zeros; the seven filter cavities of the fourth filter branch 15 are a first filter cavity D1, a second filter cavity D2, a third filter cavity D3, a fourth filter cavity D4, a fifth filter cavity D5, a sixth filter cavity D6 and a seventh filter cavity D7 of the fourth filter branch 15.

The fourth filtering branch 15 and the second filtering branch 13 are divided into five rows arranged along a first direction L1, the fourth filtering branch 15 is provided with a second filtering cavity D2, a first filtering cavity D1 and a seventh filtering cavity D7 which are arranged in a row and arranged along a second direction L2, the fourth filtering cavity D3, the fifth filtering cavity D5 and the sixth filtering cavity D6 of the fourth filtering branch 15 are provided with a row and arranged along the second direction L2, and the fourth filtering cavity D4 of the fourth filtering branch 15 is provided with a sixth filtering cavity B6 of the second filtering branch 13 which are arranged in a row and arranged along the second direction L2.

As shown in fig. 10 and 12, fig. 12 is a schematic diagram of the topology of the fourth filtering branch in fig. 10. Inductive cross coupling is respectively performed between the first filtering cavity D1 and the third filtering cavity D3 of the fourth filtering branch 15 and between the fifth filtering cavity D5 and the seventh filtering cavity D7, and the third filtering cavity D3 and the fifth filtering cavity D5 of the fourth filtering branch 15 are capacitively cross-coupled to form three cross-coupling zeros of the fourth filtering branch 15. The fourth filtering branch 15 realizes zero suppression by setting three cross-coupling zeros, so that the fourth filtering branch 15 meets design requirements, and debugging is facilitated.

The first filtering cavity D1 to the third filtering cavity D3 of the fourth filtering branch 15 are arranged in a V shape, and the third filtering cavity D3 to the seventh filtering cavity D7 of the fourth filtering branch 15 are arranged in an M shape, so that the seven filtering cavities of the fourth filtering branch 15 are compactly arranged, and the size of the filter is reduced.

In the fourth filtering branch 15, the coupling bandwidth between the first filtering cavity D1 and the second filtering cavity D2 is in the range of 30-38 MHz; the coupling bandwidth between the first filter cavity D1 and the third filter cavity D3 is in the range of 2-7 MHz; the coupling bandwidth between the second filter cavity D2 and the third filter cavity D3 is in the range of 20-27 MHz; the coupling bandwidth between the third filter cavity D3 and the fourth filter cavity D4 is in the range of 14-20 MHz; the coupling bandwidth between the third filter cavity D3 and the fifth filter cavity D5 ranges from (-17) - (-11) MHz; the coupling bandwidth between the fourth filter cavity D4 and the fifth filter cavity D5 is in the range of 14-21 MHz; the coupling bandwidth between the fifth filter cavity D5 and the sixth filter cavity D6 is in the range of 15-22 MHz; the coupling bandwidth between the fifth filter cavity D5 and the seventh filter cavity D7 is in the range of 16-22 MHz; the coupling bandwidth between the sixth filter cavity D6 and the seventh filter cavity D7 is in the range of 25-33 MHz.

The resonant frequencies of the first filter cavity D1 through the seventh filter cavity D7 of the fourth filter branch 15 are sequentially in the following ranges: 1769-1771MHz, 1773-1775MHz, 1769-1771MHz, 1755-1757MHz, 1768-1770MHz, 1783-1785MHz and 1769-1771 MHz. Therefore, the bandwidth of the fourth filtering branch 15 of the present embodiment is located in the range of 1749-1793MHz, and the bandwidth of the fourth filtering branch 15 can be accurately controlled, so as to meet the design requirement of the filter.

As shown in fig. 6, fig. 6 is a schematic diagram of simulation results of the filter provided in the present application. The simulated bandwidth of the fourth filtering branch 15 in this embodiment is as shown in the frequency band curve 32 in fig. 6, and it can be obtained that the simulated bandwidth of the fourth filtering branch 15 is within the range of 1749-1793MHz, which meets the design requirement of the filter and can accurately control the bandwidth of the fourth filtering branch 15. The fourth filtering branch 15 suppresses the signal greater than or equal to 83dD when the frequency range is 1500-; the fourth filtering branch 15 suppresses the signal greater than or equal to 71dD when the frequency range is 1575-1616 MHz; the fourth filtering branch 15 suppresses the signal greater than or equal to 37dD when the frequency band ranges from 1665-1679 MHz; the fourth filtering branch 15 suppresses the signal at a frequency range of 1678-1746MHz to be greater than or equal to 28 dD; the fourth filtering branch circuit 15 suppresses the signal level greater than or equal to 38dD when the frequency range is 1799 and 1860 MHz; the fourth filtering branch 15 suppresses the signal greater than or equal to 78dD when the frequency range is 1859-1880 MHz; when the frequency range is 1879-2690MHz, the fourth filtering branch 15 suppresses the signal level greater than or equal to 93 dD; the out-of-band rejection etc. of the fourth filtering branch 15 can thus be improved.

As shown in fig. 13-14, fig. 13 is a schematic structural diagram of a second embodiment of a third filtering branch of the filter provided in the present application; fig. 14 is a schematic structural diagram of a second embodiment of a fourth filtering branch of the filter provided in the present application. The filter of the present embodiment differs from the filters shown in fig. 9 to 12 in that:

the third filtering cavity C3 of the third filtering branch 14 is respectively adjacent to the second filtering cavity C2, the fourth filtering cavity C4 and the fifth filtering cavity C5 of the third filtering branch 14, and the seventh filtering cavity a7, the sixth filtering cavity a6 and the third filtering cavity A3 of the first filtering branch 12; the sixth filter cavity C6 of the third filter branch 14 is arranged adjacent to the fourth filter cavity C4; the fourth filtering cavity D4 of the fourth filtering branch 15 is respectively adjacent to the first filtering cavity B1, the fifth filtering cavity B5 and the sixth filtering cavity B6 of the second filtering branch 13, and the third filtering cavity D3 and the fifth filtering cavity D5 of the fourth filtering branch 15; the first filter cavity D1 of the fourth filter branch 15 is respectively disposed adjacent to the third filter cavity D3, the fifth filter cavity D5 and the seventh filter cavity D7. Compared with the filter of the first embodiment, the filter of the present embodiment has a plurality of filter cavities arranged closely, and the volume of the filter can be reduced.

The first filtering branch 12 to the fourth filtering branch 15 of the present application may be a transmitting filtering branch or a receiving filtering branch.

The present application further provides a communication device, as shown in fig. 15, fig. 15 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:

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

the first surface and the second surface of the shell are arranged oppositely.

2. The filter of claim 1,

the eight filter cavities of the first filter branch are divided into three rows arranged along the first direction;

the seventh filtering cavities of the first filtering branch are in a row;

3. The filter of claim 2,

4. The filter according to claim 2 or 3,

seven filter cavities of the second filter branch are divided into three rows arranged along the first direction;

the sixth filtering cavities of the second filtering branch are in a row;

5. The filter of claim 4,

and a fifth filtering cavity of the second filtering branch is respectively adjacent to the first filtering cavity, the third filtering cavity, the fourth filtering cavity, the sixth filtering cavity and the seventh filtering cavity.

6. The filter of claim 4, wherein the filter comprises:

7. The filter of claim 6,

8. The filter of claim 7,

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

9. The filter of claim 8,

the bandwidth range of the first filtering branch is as follows: 1851-;

the bandwidth range of the third filtering branch is as follows: 1851-;

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.