CN212323178U

CN212323178U - Filter and communication equipment

Info

Publication number: CN212323178U
Application number: CN202020837032.8U
Authority: CN
Inventors: 符其略; 李华
Original assignee: Anhui Tatfook Technology Co Ltd
Current assignee: Anhui Tatfook Technology Co Ltd
Priority date: 2020-05-15
Filing date: 2020-05-15
Publication date: 2021-01-08
Anticipated expiration: 2030-05-15

Abstract

The application discloses a filter and communication equipment. The filter includes: a housing having a first direction and a second direction which are arranged perpendicular to each other; the filtering branch is arranged on the shell and consists of eleven filtering cavities, the fifth filtering cavity and the seventh filtering cavity of the filtering branch and the first filtering cavity and the eleventh filtering cavity of the filtering branch are respectively subjected to inductive cross coupling, and the third filtering cavity and the fifth filtering cavity and the eighth filtering cavity and the tenth filtering cavity of the filtering branch are respectively subjected to capacitive cross coupling to form four cross coupling zeros of the filtering branch; wherein the bandwidth range of the filter is 3400MHz-3600 MHz. In this way, the stop-band rejection performance of the filter can be improved.

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 arrangement of a plurality of filter cavities in the existing cavity filter is complex and irregular, the size of the filter is increased, and the stop band inhibition performance of the cavity filter is poor.

SUMMERY OF THE UTILITY MODEL

The application provides a filter and communication equipment, so as to improve stop band suppression performance of the filter.

In order to solve the technical problem, the application adopts a technical scheme that: there is provided a filter comprising: a housing having a first direction and a second direction which are arranged perpendicular to each other; the filtering branch is arranged on the shell and consists of eleven filtering cavities, the fifth filtering cavity and the seventh filtering cavity of the filtering branch and the first filtering cavity and the eleventh filtering cavity of the filtering branch are respectively subjected to inductive cross coupling, and the third filtering cavity and the fifth filtering cavity and the eighth filtering cavity and the tenth filtering cavity of the filtering branch are respectively subjected to capacitive cross coupling to form four cross coupling zeros of the filtering branch; wherein the bandwidth range of the filter is 3400MHz-3600 MHz.

Optionally, the eleven filter cavities of the filter branch are divided into three rows arranged along the second direction; the fourth filtering cavities and the sixth filtering cavities of the filtering branch are in a row and are sequentially arranged along the first direction; the eleventh filtering cavity, the first filtering cavity, the second filtering cavity, the third filtering cavity, the fifth filtering cavity and the seventh filtering cavity of the filtering branch are in a row and are sequentially arranged along the first direction; the eighth filtering cavity, the ninth filtering cavity and the tenth filtering cavity of the filtering branch are in a row and are sequentially arranged along the first direction; the sixth filtering cavity, the seventh filtering cavity and the eighth filtering cavity of the filtering branch circuit are arranged in a straight line, and the seventh filtering cavity is positioned between the sixth filtering cavity and the eighth filtering cavity. Eleven filter cavities are divided into three rows which are sequentially arranged along the second direction, and the eleven filter cavities are regularly arranged, so that the size of the filter branch is reduced, and further, the size of the filter is reduced.

Optionally, a first window is respectively arranged between the fifth filtering cavity and the seventh filtering cavity of the filtering branch circuit, and between the first filtering cavity and the eleventh filtering cavity; and flying rods are arranged between the third filtering cavity and the fifth filtering cavity of the filtering branch circuit and between the eighth filtering cavity and the tenth filtering cavity of the filtering branch circuit.

Optionally, the flying bar comprises a support clamping seat and a capacitive coupling flying bar, the capacitive coupling flying bar is fixed on the support clamping seat, the first support clamping seat is provided with a window between the third filtering cavity and the fifth filtering cavity of the filtering branch, and the second support clamping seat is provided with a window between the eighth filtering cavity and the tenth filtering cavity. Capacitive cross coupling can be achieved by capacitively coupling the flying bar.

Optionally, the coupling 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 with the first coupling portion and the second coupling portion.

Optionally, metal coupling alloys are respectively arranged between the first filtering cavity and the second filtering cavity, between the fifth filtering cavity and the seventh filtering cavity, and between the first filtering cavity and the eleventh filtering cavity of the filtering branch;

optionally, the first filter cavity to the tenth filter cavity of the filter branch are sequentially window-coupled, and the first filter cavity of the filter branch is window-coupled with the eleventh filter cavity.

Optionally, each filter cavity is provided with: the resonance rod comprises a U-shaped side wall and a hollow inner cavity formed by the U-shaped side wall; one end of the tuning rod is arranged in the hollow inner cavity; wherein, the both ends of U-shaped lateral wall are to the direction bending extension of keeping away from hollow inner chamber to form disc structure at the both ends of U-shaped lateral wall, disc structure and the bottom parallel arrangement of U-shaped lateral wall. The disc-shaped structures at the two ends of the U-shaped side wall can increase the signal coupling amount of the resonant rod, and the resonant frequency of the resonant cavity can be adjusted by adjusting the depth of the tuning rod in the hollow inner cavity.

Optionally, the housing is further provided with a mounting post, and the U-shaped side wall is fixed on the mounting post.

The filter further comprises: the first port is connected with the first filtering cavity of the filtering branch circuit; and the second port is connected with the tenth filtering cavity of the filtering branch circuit. The filtering branch circuit is convenient to design and manufacture by arranging the first port and the second port, and is favorable for improving the implementation of a scheme.

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 which are arranged perpendicular to each other; the filtering branch is arranged on the shell and consists of eleven filtering cavities, the fifth filtering cavity and the seventh filtering cavity of the filtering branch and the first filtering cavity and the eleventh filtering cavity of the filtering branch are respectively subjected to inductive cross coupling, and the third filtering cavity and the fifth filtering cavity and the eighth filtering cavity and the tenth filtering cavity of the filtering branch are respectively subjected to capacitive cross coupling to form four cross coupling zeros of the filtering branch; wherein the bandwidth range of the filter is 3400MHz-3600 MHz. In the embodiment of the application, the inductive cross coupling is respectively performed between the fifth filtering cavity and the seventh filtering cavity of the filtering branch and between the first filtering cavity and the eleventh filtering cavity of the filtering branch, so that the high-end rejection of the bandwidth of the filtering branch can be well controlled, and the better high-end rejection of the bandwidth can be obtained; in addition, the bandwidth range of the filtering branch circuit is 3400MHz-3600MHz, and the bandwidth of the filtering branch circuit can be accurately controlled.

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 diagram of the structure of the flying rod in the filter of FIG. 1;

FIG. 4 is a schematic structural diagram of a tuning rod, a resonant rod and a mounting post combined structure of the filter cavity 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.

First, a filter is provided, please refer to fig. 1 and fig. 2, in which fig. 1 is a schematic structural diagram of a first embodiment of the filter of the present application, and fig. 2 is a schematic topological structural diagram of the filter of fig. 1. The filter 10 of the present embodiment includes: a housing 11 and eleven filter chambers, wherein the housing 11 has a first direction x and a second direction y arranged perpendicular to each other; the filtering branch 12 is arranged on the shell 11 and consists of eleven filtering cavities.

Specifically, the eleven filter cavities of the filter branch 12 include: a first filtering cavity A1, a second filtering cavity A2, a third filtering cavity A3, a fourth filtering cavity A4, a fifth filtering cavity A5, a sixth filtering cavity A6, a seventh filtering cavity A7, an eighth filtering cavity A8, a ninth filtering cavity A9, a tenth filtering cavity A10 and an eleventh filtering cavity A11; inductive cross coupling is respectively performed between the fifth filtering cavity A5 and the seventh filtering cavity A7, between the first filtering cavity A1 and the eleventh filtering cavity A11 of the filtering branch 12, capacitive cross coupling is respectively performed between the third filtering cavity A3 and the fifth filtering cavity A5, and between the eighth filtering cavity A8 and the tenth filtering cavity A10 of the filtering branch 12; wherein, the bandwidth range of the filter 10 is 3400MHz-3600 MHz.

It can be seen that, inductive cross-coupling is respectively performed between the fifth filter cavity a5 and the seventh filter cavity a7, and between the first filter cavity a1 and the eleventh filter cavity a11 of the filter branch 12, so that high-end rejection of the bandwidth of the filter branch 12 can be well controlled, and good high-end rejection of the bandwidth is obtained, and capacitive cross-coupling is respectively performed between the third filter cavity A3 and the fifth filter cavity a5, and between the eighth filter cavity A8 and the tenth filter cavity a10 of the filter branch 12, so that two capacitive coupling zeros can be realized, low-end rejection of the bandwidth of the filter branch 12 can be well controlled, and good low-end rejection of the bandwidth is obtained, and therefore, the stop band rejection performance of the filter 10 can be improved; in addition, the bandwidth range of the filtering branch 12 is 3400MHz-3600MHz, and the bandwidth of the filtering branch 12 can be accurately controlled.

Specifically, as shown in fig. 2, the fifth filter cavity a5 and the seventh filter cavity a7 of the filter branch 12 are inductively cross-coupled to form an inductive coupling zero L₁(ii) a First of allThe filter cavity A1 and the eleventh filter cavity A11 are inductively cross-coupled to form an inductive coupling zero point L₂(ii) a The third filter cavity A3 and the fifth filter cavity A5 of the filter branch 12 are capacitively cross-coupled to form a capacitive coupling zero point C₁(ii) a The eighth filter cavity A8 and the tenth filter cavity A10 are capacitively cross-coupled to form a capacitive coupling zero point C₂To form the four cross-coupling zeros of the filter branch 12. The cross-coupling zero is also referred to as a transmission zero. The transmission zero is the transmission function of the filter 10 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.

Alternatively, as shown in fig. 1, the eleven filter cavities of the filter branch 12 are divided into three columns arranged along the second direction y; the fourth filtering cavity a4 and the sixth filtering cavity a6 of the filtering branch 12 are in a row and are sequentially arranged along the first direction x; the eleventh filtering cavity a11, the first filtering cavity a1, the second filtering cavity a2, the third filtering cavity A3, the fifth filtering cavity a5 and the seventh filtering cavity a7 of the filtering branch 12 are in a row and are sequentially arranged along the first direction x; the eighth filtering cavity A8, the ninth filtering cavity a9 and the tenth filtering cavity a10 of the filtering branch 12 are in a row and are sequentially arranged along the first direction x; the sixth filtering cavity a6, the seventh filtering cavity a7 and the eighth filtering cavity A8 of the filtering branch 12 are arranged in a straight line, and the seventh filtering cavity a7 is located between the sixth filtering cavity a6 and the eighth filtering cavity A8.

It can be seen that the eleven filter cavities are divided into three rows arranged in sequence along the second direction y, and the eleven filter cavities are regularly arranged, so as to reduce the volume of the filter branch 12 and thus the filter 10.

Optionally, first windows are respectively arranged between the fifth filter cavity a5 and the seventh filter cavity a7, and between the first filter cavity a1 and the eleventh filter cavity a11 of the filter branch 12; flying rods are arranged between the third filtering cavity A3 and the fifth filtering cavity A5 of the filtering branch circuit 12 and between the eighth filtering cavity A8 and the tenth filtering cavity A10.

Referring to fig. 3, fig. 3 is a schematic structural diagram of a flying rod in the filter of fig. 1. Optionally, the flying bar comprises a support clamping seat 70 and a capacitive coupling flying bar 60, the capacitive coupling flying bar 60 is fixed on the support clamping seat 70, a first support clamping seat is arranged on a window between the third filter cavity A3 and the fifth filter cavity a5 of the filter branch 12, and a second support clamping seat is arranged on a window between the eighth filter cavity A8 and the tenth filter cavity a 10. Capacitive cross coupling can be achieved by capacitively coupling the flying bar.

Specifically, the capacitively coupled flying bar 60 includes a first coupling portion 610, a second coupling portion 620 and a connecting portion 630, two ends of the connecting portion 630 are respectively connected to the first coupling portion 610 and the second coupling portion 620, and the first coupling portion 610 and the second coupling portion 620 are located on the same side of the connecting portion 630. The first coupling part 610, the connecting part 630 and the second coupling part 620 are connected in sequence to form the capacitive coupling flying bar 60; the first coupling part 610 is coupled to the resonance rod 20 in the third filter cavity A3 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 fifth filter cavity a5 such that a coupling capacitance is formed between the second coupling part 620 and the resonance rod 20.

Similarly, a coupling probe is also arranged between the sixth filter cavity a6 and the eighth filter cavity A8, and the structure and the specific connection mode of the coupling probe are similar to those of the coupling probe arranged between the third filter cavity A3 and the fifth filter cavity a5, which are not described herein again.

As shown in fig. 1 and 3, the supporting clamp 70 may be disposed on the housing 11, and the supporting clamp 70 is provided with a through hole (not shown), wherein the connecting portion 630 penetrates through the through hole to fix the capacitively coupled flying bar 60 on the supporting clamp 70.

The capacitively coupled flying bar 60 of this embodiment may be implemented by a metal probe, and the support holder 70 may be implemented by PTFE or engineering plastic. For example, a metal flying bar is arranged between the eighth filter cavity A8 and the tenth filter cavity a10 of the filter branch 12, the metal flying bar comprises a screw and a metal sheet connected with the screw, the screw is used for fixing the metal sheet on a bottom platform between the eighth filter cavity A8 and the tenth filter cavity a10, the diameter of the bottom platform can be phi 5mm, and the metal flying bar is arranged at the side of the resonance bar of the eighth filter cavity A8 and the side of the resonance bar of the tenth filter cavity a10, so that the capacitive cross coupling between the eighth filter cavity A8 and the tenth filter cavity a10 of the filter branch 12 can be realized through the metal flying bar.

As shown in fig. 1, the first filtering cavity a1 to the tenth filtering cavity a11 of the filtering branch 12 are sequentially window-coupled, the first filtering cavity a1 of the filtering branch 12 is window-coupled with the eleventh filtering cavity a11, and a second window is disposed between the two sequentially-coupled filtering cavities of the filtering branch 12. That is, a second window is disposed between the first filtering cavity a1 and the second filtering cavity a2, a second window is disposed between the second filtering cavity a2 and the third filtering cavity A3, a second window is disposed between the third filtering cavity A3 and the fourth filtering cavity a4, a second window is disposed between the fourth filtering cavity a4 and the fifth filtering cavity a5, a second window is disposed between the fifth filtering cavity a5 and the sixth filtering cavity A6, a second window is disposed between the sixth filtering cavity A6 and the seventh filtering cavity a7, a second window is disposed between the seventh filtering cavity a7 and the eighth filtering cavity A8, a second window is disposed between the eighth filtering cavity A8 and the ninth filtering cavity a9, and a second window is disposed between the ninth filtering cavity a9 and the tenth filtering cavity a 10.

Therefore, the second window between two adjacent filter cavities from the first filter cavity a1 to the tenth filter cavity a10 on the coupling path of the filter branch 12 is pure window coupling, which reduces the cost of the filter 10.

Optionally, the first window and the second window are each provided with a first tuning rod 31 for adjusting the coupling strength, in particular, the first tuning rod 31 may be used for adjusting the coupling bandwidth between the fifth filter cavity a5 and the seventh filter cavity a7, and between the first filter cavity a1 and the eleventh filter cavity a 11. Electromagnetic energy can be transmitted between two adjacent filter cavities on the coupling path through the filter branch 12 through the window, and the coupling bandwidth can be adjusted through the first tuning rod 31 of the filter branch.

Further, as shown in fig. 1, a metal coupling alloy 80 is respectively disposed between the first filter cavity a1 and the second filter cavity a2, between the fifth filter cavity a5 and the seventh filter cavity a7, and between the first filter cavity a1 and the eleventh filter cavity a11 of the filter branch 12.

Referring to fig. 4, fig. 4 is a schematic structural diagram of a tuning rod, a resonant rod and a mounting post combined structure of the filter cavity of fig. 1. Optionally, each filter cavity is provided with: a resonant rod 20 including a U-shaped sidewall 210 and a hollow interior 220 formed by the U-shaped sidewall 210; a tuning rod 30, one end of the tuning rod 30 being disposed within the hollow interior 220; the two ends of the U-shaped sidewall 210 are bent and extended away from the hollow cavity 220, so as to form a disc-shaped structure 230 at the two ends of the U-shaped sidewall 210 and parallel to the bottom of the U-shaped sidewall 210. The housing 11 is further provided with a mounting post 40, the U-shaped sidewall 210 is fixed on the mounting post 40, and the resonant rod 20 is fixed on the housing 11 through the mounting post 40.

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

Further, a mounting hole (not shown) may be formed in the bottom of the U-shaped sidewall 210, one end of the mounting post 40 is fixed to 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 to 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.

Optionally, the eleven filter cavities 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 20 may also be an M8 or M4 screw rod, and be made of invar, copper, or silver.

Eleven filter chambers have the same size, so that the production is convenient and the cost is saved. The eleven filter cavities may have a radius of less than 21mm, e.g., 20mm, 19mm, 18mm, etc.

It can be seen that the resonant rod 20 can be secured to the housing 11 by the mounting post 40 and the resonant frequency of the resonant cavity can be adjusted by adjusting the depth of the tuning rod 30 within the hollow interior 220.

Further, the filter 10 further includes a cover plate (not shown) covering the eleven filter cavities, and the other end of the tuning rod 30 penetrates the cover plate, wherein the tuning rod 30 may be a metal screw rod.

The filter 10 further comprises: a first port connected to the first filter cavity a1 of the filter branch 12; and a second port connected to the tenth filter cavity a10 of the filter branch 12.

The equivalent circuit of the filter 10 of this embodiment is shown in fig. 5, where the impedance Z1 at the input port is about 50 ohms, and the impedance Z2 at the output port is about 50 ohms; in order to ensure that electromagnetic signals are transmitted between eleven filter cavities of the filter 10, impedance adjusters ZV1 are respectively disposed between the input port and the first filter cavity a1, between adjacent filter cavities on the coupling path, between non-cascaded filter cavities forming cross coupling, and between the tenth filter cavity a10 and the output port, so as to achieve impedance matching.

The bandwidth range of the filter 10 of the present embodiment is: 3400MHz-3600 MHz. Specifically, the coupling bandwidth between the first port and the first filter cavity A1 ranges from 255Mhz to 288 Mhz; the coupling bandwidth between the first filter cavity a1 and the eleventh filter cavity a11 ranges from 50Mhz to 60 Mhz; the coupling bandwidth between the first filter cavity a1 and the second filter cavity a2 ranges from 178Mhz to 202 Mhz; the coupling bandwidth between the second filter cavity a2 and the third filter cavity A3 ranges from 109Mhz to 126 Mhz; the coupling bandwidth between the third filter cavity A3 and the fourth filter cavity a4 ranges from 61Mhz to 72 Mhz; the coupling bandwidth between the third filter cavity A3 and the fifth filter cavity a5 ranges from (-89) Mhz- (-77) Mhz; the coupling bandwidth between the fourth filter cavity a4 and the fifth filter cavity a5 ranges from 55Mhz to 65 Mhz; the coupling bandwidth between the fifth filter cavity a5 and the sixth filter cavity a6 ranges from 83Mhz to 96 Mhz; the coupling bandwidth between the fifth filter cavity a5 and the seventh filter cavity a7 ranges from 38Mhz to 46 Mhz; the coupling bandwidth between the sixth filter cavity a6 and the seventh filter cavity a7 ranges from 85Mhz to 98 Mhz; the coupling bandwidth between the seventh filter cavity a7 and the eighth filter cavity A8 ranges from 98Mhz to 113 Mhz; the coupling bandwidth between the eighth filter cavity A8 and the ninth filter cavity a9 ranges from 77Mhz to 90 Mhz; the coupling bandwidth between the eighth filter cavity A8 and the tenth filter cavity a10 ranges from (-98) Mhz- (-85) Mhz; the coupling bandwidth between the ninth filter cavity a9 and the tenth filter cavity a10 ranges from 118Mhz to 135 Mhz; the coupling bandwidth between the tenth filter cavity a10 and the second port is in the range of 175Mhz-199Mhz, which can meet the design requirements.

Therefore, the resonant frequencies of the first through tenth filter cavities a1 through a10 and the eleventh filter cavity a11 of the filter 10 are sequentially in the following ranges: 3502Mhz-3504Mhz, 3493Mhz-3495Mhz, 3494Mhz-3496Mhz, 3415Mhz-3417Mhz, 3498Mhz-3500Mhz, 3545Mhz-3547Mhz, 3500Mhz-3502Mhz, 3505Mhz-3507Mhz, 3431Mhz-3433Mhz, 3495Mhz-3497Mh, 3609Mhz-3611 Mh. Therefore, the resonant frequency of each resonant cavity is within the designed bandwidth range, so that the convenience of manufacturing and debugging is improved; the method can be manufactured by adopting similar specification parameters, and the required parameter range can be reached only by simple debugging in the actual process.

The simulation result of the filter 10 of the present embodiment is shown in fig. 6, and it can be known from fig. 6 that the bandwidth of the filter 10 of the present embodiment is about 3400MHz-3600 MHz; as shown in the frequency band curve S1, there are two low-end coupling zeros a, b and two high-end coupling zeros c, d. The suppression of the filter branch 12 at the frequency point 3.370GHz (m1) is-49.725 dB, the suppression of the filter branch 12 at the frequency point 3.380GHz (m2) is-38.510 dB, the suppression of the filter branch 12 at the frequency point 3.391GHz (m3) is-23.965 dB, the suppression of the frequency point 3.610GHz (m4) is-26.961 dB, the suppression of the filter branch 12 at the frequency point 3.620GHz (m5) is-40.754 dB, the suppression of the frequency point 3.630GHz (m6) is-40.754 dB, the suppression of the filter branch 12 at the frequency point 3.400GHz (m13) is-0.998 dB, and the suppression of the filter branch 12 at the frequency point 3.600GHz (m14) is-1.181 dB, so that the design requirement of out-of-band suppression of the filter 10 can be met.

The filter 10 of the present embodiment is an 11-order microwave filter applied to a 5G mobile communication system, and has a working frequency band of 3400MHz-3600MHz, and has the characteristics of small in-band loss, strong anti-interference capability, small overall size, light weight, and large power capacity. Specifically, the in-band loss is less than 1.2dB, the average loss in the pass band is less than 0.6dB, the anti-interference rejection of 10MHz outside the pass band is more than 20dB, the anti-interference rejection of a 13GHz frequency band is more than 25dB, and the normal-temperature and normal-pressure bearing power is more than 2000W.

The filter 10 in the embodiment of the application has low loss, and can ensure low energy consumption of the communication module; the filter 10 is designed by combining 11-order resonant cavities, 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 10 has a simple design scheme, low cost, and good structural and electrical performance stability; the filter 10 can meet the use of the current latest 5G mobile communication system, and the filter 10 mainly relates to the 3400MHz-3600MHz 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 92 and a radio frequency unit 91 connected to the antenna 92, the radio frequency unit 91 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 91 may be integrated with the Antenna 92 to form an Active Antenna Unit (AAU).

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

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 which are arranged perpendicular to each other;

the filtering branch is arranged on the shell and consists of eleven filtering cavities, the fifth filtering cavity and the seventh filtering cavity of the filtering branch and the first filtering cavity and the eleventh filtering cavity of the filtering branch are respectively subjected to inductive cross coupling, and the third filtering cavity and the fifth filtering cavity and the eighth filtering cavity and the tenth filtering cavity of the filtering branch are respectively subjected to capacitive cross coupling to form four cross coupling zeros of the filtering branch;

the bandwidth range of the filter is 3400MHz-3600 MHz.

2. The filter of claim 1,

eleven filter cavities of the filter branch circuit are divided into three rows arranged along the second direction;

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

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

the eighth filtering cavity, the ninth filtering cavity and the tenth filtering cavity of the filtering branch are in a row and are sequentially arranged along the first direction;

and the sixth filtering cavity, the seventh filtering cavity and the eighth filtering cavity of the filtering branch circuit are linearly arranged, and the seventh filtering cavity is positioned between the sixth filtering cavity and the eighth filtering cavity.

3. The filter according to claim 2, wherein a first window is respectively arranged between the fifth filter cavity and the seventh filter cavity of the filter branch and between the first filter cavity and the eleventh filter cavity of the filter branch;

and flying rods are arranged between the third filtering cavity and the fifth filtering cavity of the filtering branch circuit and between the eighth filtering cavity and the tenth filtering cavity of the filtering branch circuit.

4. The filter according to claim 3, wherein the flying bar comprises a support clamping seat and a capacitive coupling flying bar, the capacitive coupling flying bar is fixed on the support clamping seat, a first support clamping seat is arranged on a window between the third filtering cavity and the fifth filtering cavity of the filtering branch, and a second support clamping seat is arranged on a window between the eighth filtering cavity and the tenth filtering cavity.

5. The filter of claim 4, wherein the capacitively coupled 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.

6. The filter of claim 5,

metal coupling alloys are respectively arranged between the first filtering cavity and the second filtering cavity, between the fifth filtering cavity and the seventh filtering cavity and between the first filtering cavity and the eleventh filtering cavity of the filtering branch circuit;

and the first filtering cavity to the tenth filtering cavity of the filtering branch circuit are sequentially coupled through windows, and the first filtering cavity of the filtering branch circuit is coupled with the eleventh filtering cavity through a window.

7. The filter of claim 6, wherein each of the filter cavities has disposed therein:

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

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

the two ends of the U-shaped side wall bend and extend in the direction away from the hollow inner cavity, so that disc-shaped structures are formed at the two ends of the U-shaped side wall, and the disc-shaped structures are arranged in parallel with the bottom of the U-shaped side wall.

8. The filter of claim 7, wherein the housing further comprises a mounting post, and the U-shaped sidewall is secured to the mounting post.

9. The filter of claim 7,

the filter further comprises:

the first port is connected with the first filtering cavity of the filtering branch circuit;

and the second port is connected with the tenth filtering cavity of the filtering branch circuit.

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.