CN113497316A

CN113497316A - Filter and communication equipment

Info

Publication number: CN113497316A
Application number: CN202010271310.2A
Authority: CN
Inventors: 陈砚昌
Original assignee: Shenzhen Tatfook Technology Co Ltd
Current assignee: Shenzhen Tatfook Technology Co Ltd
Priority date: 2020-04-08
Filing date: 2020-04-08
Publication date: 2021-10-12
Anticipated expiration: 2040-04-08
Also published as: CN113497316B

Abstract

The application discloses a filter and communication equipment. The filter includes: a housing having a first direction and a second direction perpendicular to each other; ten filter cavities are arranged on the shell and are sequentially coupled along the main coupling path, and capacitive cross coupling is respectively carried out between a second filter cavity and a fourth filter cavity, between the fourth filter cavity and a sixth filter cavity, between the sixth filter cavity and an eighth filter cavity and between the eighth filter cavity and the tenth filter cavity of the ten filter cavities, so as to form four capacitive coupling zeros of the filter; wherein, ten filter chambers are divided into three columns which are arranged in sequence along the second direction. By the mode, the material consistency of the filter is improved, the size of the filter is reduced, and the cost is saved.

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

The cavity filter is a key device of a modern mobile communication system and is widely applied to wireless communication base stations and various communication terminals; the cavity filter is composed of a radio frequency connector, a cavity, a cover plate, a plurality of resonator units and a frequency tuning and coupling strength adjusting component, wherein the resonant frequencies of the plurality of resonator units are distributed in the passband range, and the cavity filter has a blocking function on signals outside the resonant frequencies, so that the function of selecting microwave transmission signals is realized; the cavity filter has the advantages of reliable structure, wide filtering frequency band, parasitic pass band far away from a channel, high Q value, stable electrical property, good heat dissipation performance and the like.

The inventor of the application finds that the existing cavity filter has a large volume in long-term research and development work, and in order to improve the performance such as out-of-band rejection, a coupling zero point is usually formed between non-cascaded filter cavities, but the types of filter materials are increased, the complexity is improved, and the cost is high.

Disclosure of Invention

The technical problem that this application mainly solved provides a wave filter and communication equipment to improve the material uniformity of wave filter, reduce the volume of wave filter, practice thrift the cost.

In order to solve the technical problem, the application adopts a technical scheme that: a filter is provided. The filter includes: a housing having a first direction and a second direction perpendicular to each other; ten filter cavities are arranged on the shell and sequentially coupled along a main coupling path, and capacitive cross coupling is respectively performed between a second filter cavity and a fourth filter cavity, between a fourth filter cavity and a sixth filter cavity, between the sixth filter cavity and an eighth filter cavity and between the eighth filter cavity and the tenth filter cavity of the ten filter cavities, so as to form three capacitive coupling zeros of the filter; wherein the ten filter cavities are divided into three rows arranged in sequence along the second direction.

Optionally, a first filter cavity, a second filter cavity and a third filter cavity of the ten filter cavities are in a row and are sequentially arranged along the first direction; a fourth filtering cavity, a sixth filtering cavity, an eighth filtering cavity and a tenth filtering cavity of the ten filtering cavities are in a row and are sequentially arranged along the first direction; a fifth filtering cavity, a seventh filtering cavity and a ninth filtering cavity of the ten filtering cavities are in a row and are sequentially arranged along the first direction; the projection of the center of the third filter cavity in the first direction is located between the projection of the center of the fourth filter cavity and the projection of the center of the sixth filter cavity in the first direction, and the projection of the center of the sixth filter cavity in the first direction is located between the projection of the center of the fifth filter cavity and the projection of the center of the seventh filter cavity in the first direction. Ten filtering cavities are arranged in three rows, and the three rows of filtering cavities are arranged in a staggered manner, so that the rows of cavities of the filter are regular, the processing is convenient, and the volume is reduced.

Optionally, the ten filter cavities are sequentially and adjacently arranged along the main coupling path, first windows are arranged between any group of adjacently arranged filter cavities, and each first window is provided with an adjusting rod and a metal coupling rib. Electromagnetic energy transmission and adjustment between the adjacent filter cavities can be realized, and the signal coupling strength between the adjacent filter cavities is enhanced.

Optionally, a flying bar is respectively disposed between the second filtering cavity and the fourth filtering cavity of the ten filtering cavities, between the fourth filtering cavity and the sixth filtering cavity of the ten filtering cavities, between the sixth filtering cavity and the eighth filtering cavity of the ten filtering cavities, and between the eighth filtering cavity and the tenth filtering cavity of the ten filtering cavities. The four low-end coupling zeros of the filter are realized, and the stop band rejection performance of the filter is improved.

Optionally, the flying bar includes a first coupling portion, a second coupling portion and a connecting portion, and two ends of the connecting portion are respectively connected to the first coupling portion and the second coupling portion; the first coupling part and the second coupling part are arranged in a disc shape. The flying rod is simple in structure, simple to machine and capable of saving cost.

Optionally, the filter further comprises a low-pass filtering module coupled to a tenth of the ten filter cavities. The low-pass filtering module is used for performing low-pass filtering on the electromagnetic signal of the filter to obtain a low-frequency signal.

Optionally, the filtering cavity is provided with: the resonance rod comprises a side wall and a hollow inner cavity formed by the side wall; a tuning rod, one end of the tuning rod being disposed within the hollow interior. The resonant frequency of the resonant cavity can be adjusted by adjusting the depth of the tuning rod within the hollow interior.

Optionally, the side walls include a first U-shaped side wall, a second U-shaped side wall, and a third U-shaped side wall, and two ends of the second U-shaped side wall are respectively connected to one end of the first U-shaped side wall and one end of the third U-shaped side wall; wherein the opening direction of the second U-shaped side wall is opposite to the opening direction of the first U-shaped side wall and the opening direction of the third U-shaped side wall. This structure can form the turn-over structure at both ends of the side wall 210, and the turn-over structure at both ends of the side wall 210 can increase the signal coupling amount of the resonant rod 20.

Optionally, the frequency band of the filter is 924MHz to 961 MHz.

In order to solve the above technical problem, the present application adopts another technical solution: a communication device is provided. The communication equipment comprises an antenna and a radio frequency unit connected with the antenna, wherein the radio frequency unit comprises the filter and is used for filtering radio frequency signals.

The beneficial effect of this application is: different from the prior art, the filter of the embodiment of the application comprises: a housing having a first direction and a second direction perpendicular to each other; ten filter cavities are arranged on the shell and are sequentially coupled along the main coupling path, and capacitive cross coupling is respectively carried out between a second filter cavity and a fourth filter cavity, between the fourth filter cavity and a sixth filter cavity, between the sixth filter cavity and an eighth filter cavity and between the eighth filter cavity and the tenth filter cavity of the ten filter cavities, so as to form four capacitive coupling zeros of the filter; wherein, ten filter chambers are divided into three columns which are arranged in sequence along the second direction. The filter of the embodiment of the application can realize four capacitive coupling zeros, and can ensure the out-of-band rejection and other performances of the filter; the four coupling zeros are the same in type and can be realized by adopting the same material, so that the material consistency of the filter can be improved, the process is simplified, and the cost is saved; meanwhile, ten filter cavities are divided into three rows which are sequentially arranged along the second direction, so that the filter cavities are regular, the overlarge sizes of the filter in the first direction and the filter in the second direction can be avoided, the size of the filter is favorably reduced, and the cost is saved.

Drawings

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

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

FIG. 2 is a schematic diagram of the topology of the filter of the embodiment of FIG. 1;

FIG. 3 is a schematic structural diagram of a tuning rod, a resonant rod and a mounting post assembly of the filter of FIG. 1;

FIG. 4 is a schematic structural diagram of a combination structure of a flying rod and a fixed seat in the filter of FIG. 1;

FIG. 5 is a schematic diagram of an equivalent circuit configuration of the filter of the embodiment of FIG. 1;

FIG. 6 is a diagram illustrating a simulated structure of the filter of the embodiment of FIG. 1;

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

Detailed Description

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, 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 application.

The terms "first" and "second" in this application are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. In the description of the present application, "plurality" means at least two, e.g., two, three, etc., unless explicitly specifically limited otherwise. Furthermore, the terms "include" and "have," as well as any variations thereof, are intended to cover non-exclusive inclusions. For example, a process, method, system, article, or apparatus that comprises a list of steps or elements is not limited to only those steps or elements listed, but may alternatively include other steps or elements not listed, or inherent to such process, method, article, or apparatus.

The present application first proposes a filter, as shown in fig. 1 to 6, fig. 1 is a schematic structural diagram of an embodiment of the filter of the present application; FIG. 2 is a schematic diagram of the topology of the filter of the embodiment of FIG. 1; FIG. 3 is a schematic structural diagram of a tuning rod, a resonant rod and a mounting post assembly of the filter of FIG. 1; FIG. 4 is a schematic structural diagram of a combination structure of a flying rod and a fixed seat in the filter of FIG. 1; FIG. 5 is a schematic diagram of an equivalent circuit configuration of the filter of the embodiment of FIG. 1; fig. 6 is a schematic diagram of a simulation structure of the filter of the embodiment of fig. 1. The filter 10 of the present embodiment includes: a housing 11 and a tenth filter chamber a1-a10, wherein the housing 11 has a first direction x and a second direction y perpendicular to each other; ten filter cavities a1-a10 are provided on the housing 11, ten filter cavities a1-a10 are coupled in sequence along the main coupling path and capacitively cross-coupled between the second filter cavity a2 and the fourth filter cavity a4, between the fourth filter cavity a4 and the sixth filter cavity A6, between the sixth filter cavity A6 and the eighth filter cavity A8, and between the eighth filter cavity A8 and the tenth filter cavity a10, respectively, to form four capacitive coupling zeros of the filter 10.

Wherein, ten filter cavities A1-A10 include: the filter comprises 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, an eighth filter cavity A8, a ninth filter cavity A9 and a tenth filter cavity A10.

The filter cavity is a communication device for frequency selection and signal suppression, the filter cavity mainly plays a role in frequency control, and the filter cavity is required by the communication device related to frequency transmission and reception.

Compared with the prior art, the filter 10 in the embodiment of the application can realize four capacitive coupling zeros, and can ensure the out-of-band rejection and other performances of the filter 10; the four coupling zeros are of the same type and can be realized by adopting the same material, so that the material consistency of the filter 10 can be improved, the process is simplified, and the cost is saved; meanwhile, the ten filter cavities A1-A10 are divided into three rows arranged in sequence along the second direction y, so that the cavities of the filter 10 are arranged regularly, the overlarge sizes of the filter 10 in the first direction x and the second direction y can be avoided, the size of the filter 10 is reduced, and the cost is saved.

Optionally, as shown in fig. 1, a first filter cavity a1, a second filter cavity a2 and a third filter cavity A3 of ten filter cavities a1-a10 are in a row and are sequentially arranged along a first direction x; the fourth filter cavity A4, the sixth filter cavity A6, the eighth filter cavity A8 and the tenth filter cavity A10 are in a row and are sequentially arranged along the first direction x; the fifth filtering cavity A5, the seventh filtering cavity A7 and the ninth filtering cavity A9 are divided into a row and are sequentially arranged along the first direction x; the projection of the centre of third filter chamber A3 in first direction x is located between the centre of fourth filter chamber a4 and the projection of the centre of sixth filter chamber a6 in first direction x, and the projection of the centre of sixth filter chamber a6 in first direction x is located between the centre of fifth filter chamber a5 and the projection of the centre of seventh filter chamber a7 in first direction x.

From the above analysis, it can be seen that the ten filter cavities a1-a10 are arranged in three rows, and the three rows are staggered, so that the filter 10 has regular cavity arrangement, and is convenient to process and reduce in size.

As shown in fig. 1 and 3, the resonance rod 20 and the tuning rod 30 are arranged in each of the ten filter cavities a1-a 10; the resonant rod 20 comprises a side wall 210 and a hollow inner cavity 220 formed by the side wall 210, and one end of the tuning rod 30 is arranged in the hollow inner cavity 220; the resonant frequency of the resonant cavity can be adjusted by adjusting the depth of the tuning rod 30 within the hollow interior 220.

The resonant rod 20, the hollow cavity 220 and the tuning rod 30 of the present embodiment are coaxially disposed.

Optionally, as shown in fig. 3, the side wall 210 includes a first U-shaped side wall 211, a second U-shaped side wall 212 and a third U-shaped side wall 213, two ends of the second U-shaped side wall 212 are respectively connected to one end of the first U-shaped side wall 211 and one end of the third U-shaped side wall 213; wherein, the opening direction of the second U-shaped side wall 212 is opposite to the opening direction of the first U-shaped side wall 211 and the opening direction of the third U-shaped side wall 213; the second U-shaped sidewall 212 forms a hollow interior 220. This structure enables the formation of a tray-flipping structure at both ends of the sidewall 210.

The tilting structure at both ends of the sidewall 210 can increase the signal coupling amount of the resonant bar 20.

Alternatively, the ten filter cavities a1-a10 of the present embodiment may be metal filter cavities, and the resonant rod 20 may be a metal resonant rod.

The material of the resonant rod 20 of the present embodiment may be the cut 1215 MS. Of course, in other embodiments, the resonant rod may be an M8 or M4 screw rod, and the like, and made of copper or silver.

The ten filter cavities A1-A10 are the same in size, so that the production is convenient, and the cost is saved. The radii of the ten filter cavities a1-a10 may be less than 39mm, e.g., 38mm, 37mm, 36mm, etc.

Optionally, as shown in fig. 1 and 3, a mounting post 40 is further disposed on the housing 11, and the sidewall 210 is fixed on the mounting post 40. The resonant rod 20 is fixed to the housing 11 by a mounting post 40.

Further, a mounting hole (not shown) may be provided on the bottom of the second U-shaped sidewall 212, one end of the mounting post 40 is fixed on the housing 11, and the other end of the mounting post 40 is mounted in the mounting hole, so as to fix the resonant rod 20 on the mounting post 40; the mounting holes may be through holes, the mounting holes may be threaded holes, and the mounting posts 40 are studs. In other embodiments, the mounting hole may also be a blind hole.

Further, the filter 10 further includes a cover plate (not shown) covering the ten filter cavities a1-a10, and the other end of the tuning rod 30 is inserted into the cover plate, wherein the tuning rod 30 may be a metal screw.

Optionally, as shown in fig. 1, ten filter cavities a1-a10 are sequentially and adjacently disposed along a main coupling path, and a first window (indicated in the drawing) is disposed between any group of adjacently disposed filter cavities, that is, a first window is disposed between two adjacent filter cavities (i.e., arranged in a cascade) that are sequentially arranged along the main coupling path, and electromagnetic energy is transmitted between two adjacent filter cavities on the main coupling path through the first window. For example, first windows are respectively disposed between the first filter cavity a1 and the second filter cavity a2, between the second filter cavity a2 and the third filter cavity A3, between the third filter cavity A3 and the fourth filter cavity a4, between the fourth filter cavity a4 and the fifth filter cavity a5, between the fifth filter cavity a5 and the sixth filter cavity A6, between the sixth filter cavity A6 and the seventh filter cavity a7, between the seventh filter cavity a7 and the eighth filter cavity A8, between the eighth filter cavity A8 and the ninth filter cavity a9, and between the ninth filter cavity a9 and the tenth filter cavity a 10.

The filter 10 of the present embodiment further includes a plurality of adjustment bars 50 and a plurality of metal coupling ribs 80.

In order to adjust the coupling strength between two adjacent filter cavities on the main coupling path, an adjusting rod 50 may be provided at each first window, for example, a first window between the first filter cavity a1 and the second filter cavity a2, a first window between the second filter cavity a2 and the third filter cavity A3, a first window between the third filter cavity A3 and the fourth filter cavity A4, a first window between the fourth filter cavity A4 and the fifth filter cavity A5, a first window between the fifth filter cavity A5 and the sixth filter cavity A6, a first window between the sixth filter cavity A6 and the seventh filter cavity A7, a first window between the seventh filter cavity A7 and the eighth filter cavity A8, a first window between the eighth filter cavity A8 and the ninth filter cavity a9, a first window between the ninth filter cavity a9 and the ninth filter cavity a10, respectively.

In order to improve the coupling strength between two adjacent filter cavities on the main coupling path, a metal coupling rib 80 may be disposed at a first window, for example, a first window between the first filter cavity a1 and the second filter cavity a2, a first window between the second filter cavity a2 and the third filter cavity A3, a first window between the third filter cavity A3 and the fourth filter cavity A4, a first window between the fourth filter cavity A4 and the fifth filter cavity A5, a first window between the fifth filter cavity A5 and the sixth filter cavity A6, a first window between the sixth filter cavity A6 and the seventh filter cavity A7, a first window between the seventh filter cavity A7 and the eighth filter cavity A8, a first window between the eighth filter cavity A8 and the ninth filter cavity a9, and a first window between the ninth filter cavity a9 and the tenth filter cavity a10, respectively.

As shown in fig. 1 and fig. 2, capacitive cross coupling is respectively performed between the second filter cavity a2 and the fourth filter cavity a4, between the fourth filter cavity a4 and the sixth filter cavity a6, between the sixth filter cavity a6 and the eighth filter cavity A8, and between the eighth filter cavity A8 and the tenth filter cavity a10, so as to form four capacitive coupling zeros of the filter 10, so as to implement four low-end coupling zeros of the filter 10, and improve the stop band rejection performance of the filter 10.

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

As shown in fig. 1 and 2, the present embodiment may provide flying bars 60 (which may be equivalent to capacitors) between the second filter cavity a2 and the fourth filter cavity a4, between the fourth filter cavity a4 and the sixth filter cavity A6, between the sixth filter cavity A6 and the eighth filter cavity A8, and between the eighth filter cavity A8 and the tenth filter cavity a10, respectively, to achieve capacitive cross coupling between the second filter cavity a2 and the fourth filter cavity a4, between the fourth filter cavity a4 and the sixth filter cavity A6, between the sixth filter cavity A6 and the eighth filter cavity A8, and between the eighth filter cavity A8 and the tenth filter cavity a10, respectively.

Alternatively, as shown in fig. 1 and 4, the flying bar 60 of the present embodiment includes: a first coupling part 610, a second coupling part 620 and a connecting part 630, wherein two ends of the connecting part 630 are respectively connected with the first coupling part 610 and the second coupling part 620; the first coupling part 610 is coupled to the resonance rod 20 in the second filter cavity a2 such that a coupling capacitance is formed between the first coupling part 610 and the resonance rod 20, and the second coupling part 620 is coupled to the resonance rod 20 in the fourth filter cavity a4 such that a coupling capacitance is formed between the second coupling part 620 and the resonance rod 20.

The first coupling portion 610 and the second coupling portion 620 of the present embodiment are both disposed in a disc shape. The flying bar 60 of the embodiment has a simple structure and simple processing, and can save cost.

As shown in fig. 1 and 4, the filter 10 further includes: the fixing seat 70 is disposed on the housing 11, the fixing seat 70 is provided with a through hole (not shown), and the connecting portion 630 penetrates through the through hole to fix the flying bar 60 and the fixing seat 70.

The flying bar 60 of the present embodiment can be implemented by a metal probe, and the fixed seat 70 is implemented by PTFE or engineering plastic.

Further, as shown in fig. 1, the filter 10 of the present embodiment further includes: an input port 12 and an output port 13, the input port 12 being connected to the first filter cavity a1 of the filter 10, the output port 13 being coupled to the tenth filter cavity a10 of the filter 10.

The input port 12 and the output port 13 are both tapped, the input port 12 is connected with the resonance rod 20 in the first filter cavity A1, and electromagnetic signals are input into the first filter cavity A1; the output port 13 is connected to the resonant rod 20 in the tenth filter chamber a10, and outputs the electromagnetic signal in the tenth filter chamber a 10.

The equivalent circuit of the filter 10 of the present embodiment is shown in fig. 5, where the impedance Z1 at the input port 12 is about 50 ohms, and the impedance Z2 at the output port 13 is about 50 ohms; in order to ensure the transmission of electromagnetic signals between the filter cavities a1-a10 of the filter 10, impedance adjusters ZV are required to be disposed between the input port 12 and the first filter cavity a1, between adjacent filter cavities on the main coupling path, between non-cascaded filter cavities forming cross coupling, and between the tenth filter cavity a10 and the output port 13, so as to realize impedance matching.

As shown in fig. 6, the simulation result of the filter 10 of the present embodiment is shown in fig. 6, and it can be seen from fig. 6 that the frequency band of the filter 10 of the present embodiment is about 924MHz to 761MHz, and the frequency band curve is shown as S1, and the frequency band curve has a low-end coupling zero: a. b, c (partial coupling zero overlap); the suppression of the frequency point 925MHz (m1) is-1.347 dB, and the suppression of the frequency point 960MHz (m2) is-0.895 dB, so that the filter 10 has the characteristic of small in-band loss (less than 1.8 dB); and the inhibition of the frequency point 915MHz (m3) is-111.315 dB, and the inhibition of the frequency point 970MHz (m4) is-30.674 dB, so that the filter 10 has the performance of strong anti-interference capability (the inhibition of 10MHz is more than 105dB outside a passband, and the inhibition of a10 GHz frequency band is more than 20 dB).

Optionally, the filter 10 of the present embodiment further includes a low-pass filtering module 120, and the low-pass filtering module 120 is coupled to the tenth filtering cavity a 10. The low-pass filtering module 120 is configured to perform low-pass filtering on the electromagnetic signal of the filter 10 to obtain a low-frequency signal.

The low-pass filtering module 120 includes a plurality of low-pass filtering units (not shown) connected in series.

The filter 10 of this embodiment is a 10-order microwave filter applied to a 5G mobile communication system, and has a working frequency band of 924MHz to 761MHz, and has the characteristics of small in-band loss (less than 1.8dB), strong anti-interference capability (the 10MHz is more than 105dB of suppression outside a passband, and the 10GHz band suppression is more than 20dB), and large power capacity (the normal temperature and normal pressure power of the filter is more than 2000W).

The filter has low loss, and can ensure low energy consumption of the communication module; the filter is designed by combining a 10-order filter cavity, and a coupling zero structure is introduced, so that the filter has strong anti-interference capability and can ensure that a communication system is not interfered by stray signals; the filter has the advantages of simple design scheme, low cost, good structure and electrical property stability; the filter can meet the use requirement of the current latest 5G mobile communication system and mainly relates to a 900MHz frequency band.

The present application further provides a communication device, as shown in fig. 7, fig. 7 is a schematic structural diagram of an embodiment of the communication device of the present application. The communication device of the present embodiment includes an antenna 32 and a radio frequency unit 31 connected to the antenna 32, the radio frequency unit 31 includes a filter 10 as shown in the above-mentioned embodiment, and the filter 10 is used for filtering a radio frequency signal.

In other embodiments, the rf Unit 31 may be integrated with the Antenna 32 to form an Active Antenna Unit (AAU).

Different from the prior art, the filter of the embodiment of the application comprises: a housing having a first direction and a second direction perpendicular to each other; ten filter cavities are arranged on the shell and are sequentially coupled along the main coupling path, and capacitive cross coupling is respectively carried out between a second filter cavity and a fourth filter cavity, between the fourth filter cavity and a sixth filter cavity, between the sixth filter cavity and an eighth filter cavity and between the eighth filter cavity and the tenth filter cavity of the ten filter cavities, so as to form four capacitive coupling zeros of the filter; wherein, ten filter chambers are divided into three columns which are arranged in sequence along the second direction. The filter of the embodiment of the application can realize four capacitive coupling zeros, and can ensure the out-of-band rejection and other performances of the filter; the four coupling zeros are the same in type and can be realized by adopting the same material, so that the material consistency of the filter can be improved, the process is simplified, and the cost is saved; meanwhile, ten filter cavities are divided into three rows which are sequentially arranged along the second direction, so that the filter cavities are regular, the overlarge sizes of the filter in the first direction and the filter in the second direction can be avoided, the size of the filter is favorably reduced, and the cost is saved.

The above description is only for the purpose of illustrating embodiments of the present application and is not intended to limit the scope of the present application, and all modifications of equivalent structures and equivalent processes, which are made by the contents of the specification and the drawings of the present application or are directly or indirectly applied to other related technical fields, are also included in the scope of the present application.

Claims

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

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

ten filter cavities are arranged on the shell and sequentially coupled along a main coupling path, and capacitive cross coupling is respectively performed between a second filter cavity and a fourth filter cavity, between a fourth filter cavity and a sixth filter cavity, between the sixth filter cavity and an eighth filter cavity and between the eighth filter cavity and the tenth filter cavity of the ten filter cavities, so as to form four capacitive coupling zeros of the filter;

wherein the ten filter cavities are divided into three rows arranged in sequence along the second direction.

2. The filter according to claim 1, wherein the first, second and third filter cavities of the ten filter cavities are in a row and are arranged in sequence along the first direction;

a fourth filtering cavity, a sixth filtering cavity, an eighth filtering cavity and a tenth filtering cavity of the ten filtering cavities are in a row and are sequentially arranged along the first direction;

a fifth filtering cavity, a seventh filtering cavity and a ninth filtering cavity of the ten filtering cavities are in a row and are sequentially arranged along the first direction;

the projection of the center of the third filter cavity in the first direction is located between the projection of the center of the fourth filter cavity and the projection of the center of the sixth filter cavity in the first direction, and the projection of the center of the sixth filter cavity in the first direction is located between the projection of the center of the fifth filter cavity and the projection of the center of the seventh filter cavity in the first direction.

3. The filter according to claim 2, wherein the ten filter cavities are sequentially arranged adjacently along the main coupling path, and a first window is arranged between any group of adjacently arranged filter cavities, and each first window is provided with an adjusting rod and a metal coupling rib.

4. The filter of claim 2, wherein flying rods are respectively arranged between the second filtering cavity and the fourth filtering cavity of the ten filtering cavities, between the fourth filtering cavity and the sixth filtering cavity of the ten filtering cavities, between the sixth filtering cavity and the eighth filtering cavity of the ten filtering cavities, and between the eighth filtering cavity and the tenth filtering cavity of the ten filtering cavities.

5. The filter according to claim 4, wherein the flying bar comprises a first coupling portion, a second coupling portion and a connecting portion, and both ends of the connecting portion are respectively connected with the first coupling portion and the second coupling portion; the first coupling part and the second coupling part are arranged in a disc shape.

6. The filter of claim 1, further comprising a low pass filtering module coupled to a tenth of the ten filter cavities.

7. The filter of claim 1, wherein the filter cavity is provided with:

the resonance rod comprises a side wall and a hollow inner cavity formed by the side wall;

a tuning rod, one end of the tuning rod being disposed within the hollow interior.

8. The filter of claim 7, wherein the sidewalls comprise a first U-shaped sidewall, a second U-shaped sidewall and a third U-shaped sidewall, and two ends of the second U-shaped sidewall are respectively connected to one end of the first U-shaped sidewall and one end of the third U-shaped sidewall;

wherein the opening direction of the second U-shaped side wall is opposite to the opening direction of the first U-shaped side wall and the opening direction of the third U-shaped side wall.

9. The filter of claim 1, wherein the frequency band of the filter is between 924MHz and 961 MHz.

10. A communication device, characterized in that the communication device comprises an antenna and a radio frequency unit connected to the antenna, the radio frequency unit comprising a filter according to any of claims 1-9 for filtering a radio frequency signal.