CN113889728A

CN113889728A - Communication device and filter thereof

Info

Publication number: CN113889728A
Application number: CN202010636085.8A
Authority: CN
Inventors: 符其略; 李华
Original assignee: Anhui Tatfook Technology Co Ltd
Current assignee: Anhui Tatfook Technology Co Ltd
Priority date: 2020-07-03
Filing date: 2020-07-03
Publication date: 2022-01-04

Abstract

The application discloses a communication device and a filter thereof. The filter includes: the filter comprises a shell and a filtering branch, wherein the shell is provided with a first direction and a second direction which are perpendicular to each other; the filtering branch is arranged on the shell, comprises ten filtering cavities which are sequentially coupled and forms four cross-coupling zero points of the filtering branch, and the bandwidth range of the filtering branch is 3400 MHz-3600 MHz; the first filtering cavity to the tenth filtering cavity of the filtering branch circuit are divided into two rows arranged along the first direction. Through the mode, zero point suppression can be realized, the suppression effect of the filtering branch is improved, the debugging index is convenient, the size of the filter can be reduced, and the miniaturization of the filter is facilitated.

Description

Communication device and filter thereof

Technical Field

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

Background

The microwave 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 microwave cavity filter structure 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 a passband range, and the microwave cavity filter structure 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 filter in the prior art is large in size, poor in performance such as out-of-band rejection and weak in anti-interference capability in long-term research and development work.

Disclosure of Invention

In order to solve the above problems of the prior art filter, the present application provides a communication device and a filter thereof.

To solve the above problem, an embodiment of the present application provides a filter, including: a housing having a first direction and a second direction perpendicular to each other; the filtering branch is arranged on the shell, comprises ten filtering cavities which are sequentially coupled and forms four cross-coupling zero points of the filtering branch, and the bandwidth range of the filtering branch is 3400 MHz-3600 MHz; the first filtering cavity to the tenth filtering cavity of the filtering branch circuit are divided into two rows arranged along the first direction.

The second filtering cavity, the third filtering cavity and the seventh filtering cavity of the filtering branch are in a row and are sequentially arranged along the second direction; the first filtering cavity, the fourth filtering cavity, the fifth filtering cavity, the sixth filtering cavity, 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 second direction. The design scheme of the filter is simple, the miniaturization of the filter is facilitated, the cost is reduced, and the filter has good stability.

The first filtering cavity and the third filtering cavity of the filtering branch are inductively cross-coupled, the first filtering cavity and the fourth filtering cavity of the filtering branch are inductively cross-coupled, the sixth filtering cavity and the eighth filtering cavity of the filtering branch are capacitively cross-coupled, and the eighth filtering cavity and the tenth filtering cavity of the filtering branch are capacitively cross-coupled to form four cross-coupling zeros of the filtering branch. Zero point suppression is realized, so that the filter branch circuit meets the design requirement, and the suppression performance of the filter branch circuit is improved.

The filter also comprises a flying rod and a supporting clamping seat, wherein the flying rod is fixed on the supporting clamping seat; and a flying rod is arranged between the sixth filtering cavity and the eighth filtering cavity of the filtering branch circuit so as to realize capacitive cross coupling.

The filter further comprises a metal coupling rib, and the metal coupling rib is arranged between the eighth filtering cavity and the tenth filtering cavity of the filtering branch circuit so as to realize capacitive cross coupling.

The filter branch circuit comprises ten filter cavities, a first filter cavity, a third filter cavity, a first filter cavity, a fourth filter cavity, a second filter cavity, a third filter cavity, a fourth filter cavity and a fourth filter cavity, wherein the ten filter cavities of the filter branch circuit are sequentially coupled, and windows are arranged between the two filter cavities, the first filter cavity and the third filter cavity of the filter branch circuit and the first filter cavity and the fourth filter cavity of the filter branch circuit to realize window coupling. The window coupling consistency is good, other materials are not needed, and the cost is reduced.

The filter further comprises an adjusting screw rod, the window is provided with the adjusting screw rod, and the adjusting screw rod is used for adjusting the coupling bandwidth between the two filter cavities.

Wherein the outer diameter range of the filter cavity is 28mm-32mm, and the height range of the filter cavity is 18mm-22 mm. The filter has small volume and is beneficial to the miniaturization of the filter.

Wherein, be provided with resonance rod and tuning rod in the filtering chamber, the resonance rod is provided with a cavity inner chamber, and the cavity inner chamber is arranged in to the one end of tuning rod for adjust the resonant frequency in filtering chamber.

In order to solve the above problem, an embodiment of the present application provides a communication device, where the communication device includes an antenna and a radio frequency unit connected to the antenna, and the radio frequency unit includes the filter of any of the above embodiments, and is configured to filter a radio frequency signal.

The filter is different from the situation of the prior art, in the application, ten filter cavities of the filter branch are divided into two rows arranged along the first direction, the filter cavities are arranged regularly, the design scheme of the filter is simple, the size of the filter can be reduced, and the miniaturization of the filter is facilitated; the ten filter cavities of the filter branch form four cross coupling zero points, so that the bandwidth range of the filter branch is 3400 MHz-3600 MHz, the suppression effect of the filter branch is improved, and the debugging index is facilitated.

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 an embodiment of the filter cavity of FIG. 1;

FIG. 3 is a schematic of the topology of the filter of FIG. 1;

FIG. 4 is a schematic diagram of an equivalent circuit configuration of the filter of FIG. 1;

FIG. 5 is a diagram of simulation results for the filter of FIG. 1;

fig. 6 is a schematic structural diagram of an embodiment of a communication device of the present application.

Detailed Description

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

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

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

As shown in fig. 1, the filtering branch 12 is disposed on the housing 11 and is composed of ten filtering cavities coupled in sequence, the ten filtering cavities of the filtering branch 12 are a first filtering cavity a1, a second filtering cavity a2, a third filtering cavity A3, a fourth filtering cavity a4, a fifth filtering cavity a5, a sixth filtering cavity a6, a seventh filtering cavity a7, an eighth filtering cavity A8, a ninth filtering cavity a9 and a tenth filtering cavity a10 of the filtering branch 12.

Further, as shown in fig. 1, the first through tenth filter cavities a1 through a10 of the filter branch 12 are divided into two columns arranged in the first direction L1. Specifically, the second filter cavity a2, the third filter cavity A3 and the seventh filter cavity a7 of the filter branch 12 are in a row and are sequentially arranged along the second direction L2; the first filtering cavity a1, the fourth filtering cavity a4, the fifth filtering cavity a5, the sixth filtering cavity a6, 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 second direction L2. The filter cavities a1-a10 of the filter branch 12 of the present embodiment are regularly arranged, so that the design scheme of the filter is simple, the production cost is reduced, and the size of the filter can be reduced.

As shown in fig. 2, fig. 2 is a schematic structural diagram of an embodiment of the filter cavity in fig. 1, a resonant rod 13 and a tuning rod 14 are arranged in ten filter cavities a1-a10 of the filter branch 12, the resonant rod 13 may have a structure without a turning plate, the resonant rod 13 forms a hollow inner cavity (not shown), and one end of the tuning rod 14 is arranged in the hollow inner cavity; the resonant frequency of the filter cavity can be adjusted by adjusting the depth of the tuning rod 14 within the hollow interior cavity.

The materials of the filter cavity, the resonant rod 13 and the tuning rod 14 can all adopt metal materials, and the metal materials can be iron, silver, copper, aluminum, titanium, gold or the like. Preferably, the resonant rod 13 is made of invar steel to improve the stability of the filter.

The filter cavity of this embodiment can be the metal filter cavity, and the diameter scope of metal filter cavity is 28mm-32mm, preferably 30mm, and the high scope of filter cavity is 18mm-22mm, preferably 20mm, and the filter of this embodiment can satisfy the design requirement, and the volume is less.

Further, the filter further includes a cover plate (not shown) covering the ten filter cavities a1-a10, and the other end of the tuning rod 14 is inserted on the cover plate, wherein the tuning rod 14 may be a metal screw.

As shown in fig. 1, ten filter cavities a1-a10 of the filter branch 12 are sequentially and adjacently arranged along a main coupling path, and windows (not shown) are respectively arranged between two adjacent filter cavities (i.e. arranged in a cascade manner) along the main coupling path, between the first filter cavity a1 and the third filter cavity A3 of the filter branch 12, and between the first filter cavity a1 and the fourth filter cavity a4, so as to implement window coupling, wherein electromagnetic energy is transmitted between the two adjacent filter cavities on the main coupling path through the windows.

In order to improve the coupling strength between two adjacent filter cavities, reinforcing ribs 18 may be further disposed at the windows, for example, the reinforcing ribs 18 may be disposed between the first filter cavity a1 and the second filter cavity a2, between the first filter cavity a1 and the third filter cavity A3, 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, and between the ninth filter cavity a9 and the tenth filter cavity a10 of the filter branch 12, respectively, so as to increase the coupling strength. In other embodiments, the reinforcing rib 18 may be selectively disposed between the eighth filter cavity A8 and the ninth filter cavity a9 of the filter branch 12 according to actual conditions.

As shown in fig. 1, the filter of the present embodiment further includes a plurality of adjusting screws 15 to adjust the coupling strength between the two filter cavities, and the adjusting screws 15 may be disposed in the above-mentioned windows, for example, the ten-fold adjusting screws 15 may be disposed between the first filter cavity a1 and the second filter cavity a2, between the first filter cavity a1 and the third filter cavity A3, between the first filter cavity a1 and the fourth filter cavity A4, 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 a 3648 and the sixth filter cavity a 465, and the ninth filter cavity a 5857323 a.

As shown in fig. 1 and fig. 3, fig. 3 is a schematic diagram of a topology structure of the filtering branch 12 in fig. 1, in which the first filtering cavity a1 and the third filtering cavity A3 of the filtering branch 12 are inductively cross-coupled, the first filtering cavity a1 and the fourth filtering cavity a4 are inductively cross-coupled, the sixth filtering cavity a6 and the eighth filtering cavity A8 are capacitively cross-coupled, and the eighth filtering cavity A8 and the tenth filtering cavity a10 are capacitively cross-coupled, so as to form four cross-coupling zeros of the filtering branch 12, so that two transmission zeros are generated at the high end and the low end of the pass band, thereby implementing a stop band rejection function and improving a rejection performance of the filter band.

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.

Specifically, in this embodiment, the first filter cavity a1 and the third filter cavity A3 of the filter branch 12 are coupled through a window, and a reinforcing rib 18 is disposed between the first filter cavity a1 and the third filter cavity A3, so that the first filter cavity a1 and the third filter cavity A3 are inductively cross-coupled to form an inductive cross-coupling zero of the filter branch 12, and the first filter cavity a1 and the fourth filter cavity a4 are coupled through a window, so that the first filter cavity a1 and the fourth filter cavity a4 are inductively cross-coupled to form another inductive cross-coupling zero of the filter branch 12.

As shown in fig. 1, the filter further includes a flying bar 171 and a supporting clamp 172, the flying bar 171 is fixed on the supporting clamp 172; in this embodiment, the flying bar 171 is disposed between the sixth filter cavity a6 and the eighth filter cavity A8 of the filter branch 12 to realize capacitive cross coupling, wherein the supporting clamp 172 may be disposed between the sixth filter cavity a6 and the eighth filter cavity A8, and the flying bar 171 may be dumbbell-shaped.

Further, as shown in fig. 1, the filter further includes a metal coupling rib 16, and the metal coupling rib 16 is disposed between the eighth filter cavity A8 and the tenth filter cavity a10 of the filter branch 12, and is used for implementing capacitive cross coupling between the eighth filter cavity A8 and the tenth filter cavity a 10. Specifically, a base (not shown) may be provided at one side of the resonance rod 13 in the eighth filter chamber A8 and one side of the resonance rod 13 in the tenth filter chamber a10, respectively, and the diameter of the base may be 5 mm; then, the two ends of the metal coupling rib 16 are respectively fixed on the base by screws to fix the metal coupling rib 16. The cross coupling structure of the embodiment is simple, the processing is convenient, and the cost can be saved.

Optionally, the filter further includes a first port 101 and a second port 102, the first filter cavity a1 of the filter branch 12 is connected to the first port 101, and the tenth filter cavity a10 of the filter branch 12 is connected to the second port 102, wherein the first port 101 and the second port 102 may be taps of the filter.

The first port 101 is connected to the first filter chamber a1, and inputs an electromagnetic signal to the first filter chamber a 1; the second port 102 is connected to the tenth filter chamber a10 and outputs an electromagnetic signal in the tenth filter chamber a 10.

The equivalent circuit of the filter of the present embodiment is shown in fig. 4, and the circuit model includes a filter cavity a1-a10 and an impedance transformer 41, the impedance at the first port 101 is about 50 ohms, and the impedance at the second port 102 is about 50 ohms; in order to ensure the normal transmission of electromagnetic signals in the transmission link, impedance transformers 41 are required to be arranged between the first port 101 and the first filter cavity a1, between adjacent filter cavities in the main coupling path, between non-cascaded filter cavities forming cross coupling, and between the tenth filter cavity a10 and the second port 102, so that the impedance through each filter cavity is matched with the impedance of the transmission link to realize signal transmission.

As shown in fig. 5, fig. 5 is a schematic diagram of a simulation result of the filter of the present application, and a simulation bandwidth of the filtering branch 12 is shown as a frequency band curve 51 in fig. 5, and it can be seen from the simulation diagram that the bandwidth of the filtering branch 12 is within a range of 3400MHz to 3600MHz, which meets the design requirement of the filter and can accurately control the bandwidth of the filtering branch 12. The suppression of the frequency point 3400MHz (m2) is-1.059 dB, and the suppression of the frequency point 3600MHz (m1) is-0.963 dB, so that the in-band loss of the filter is small (less than 0.6dB), and the filter has the performance of strong anti-interference capability (the suppression of 10MHz out of a pass band is more than 20dB, and the suppression of a 13GHz frequency band is more than 25 dB).

The filter of the embodiment can be a ten-order microwave filter applied to a 5G mobile communication system, the working frequency band of the filter is 3400 MHz-3600 MHz, and the filter has the characteristics of small in-band loss, strong anti-jamming capability and large power capacity (the normal temperature and normal pressure bearing power is more than 2000W).

In summary, the filter provided by the embodiment is designed by combining the ten-order filter cavities, the filter design scheme is simple, and the cavity arrangement is regular, so that the design cost can be reduced, and the size of the filter can be reduced; ten filter cavities of the filter branch circuit 12 form four cross-coupling zero points, so that zero point suppression can be realized, the filter has strong anti-interference capability, the communication system is ensured not to be interfered by stray signals, and the use of the current latest 5G mobile communication system can be met.

The present application further provides a communication device, as shown in fig. 6, fig. 6 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).

The principle and the implementation of the present application are explained herein by applying specific examples, and the above description of the embodiments is only used to help understand the method and the core idea of the present application; meanwhile, for a person skilled in the art, according to the idea of the present application, there may be variations in the specific embodiments and the application scope, and in summary, the content of the present specification should not be construed as a limitation to 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;

the filtering branch circuit is arranged on the shell, comprises ten filtering cavities which are sequentially coupled and forms four cross-coupling zero points of the filtering branch circuit, and the bandwidth range of the filtering branch circuit is 3400 MHz-3600 MHz;

and the first filtering cavity to the tenth filtering cavity of the filtering branch circuit are divided into two rows arranged along the first direction.

2. The filter of claim 1,

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

the first filtering cavity, the fourth filtering cavity, the fifth filtering cavity, the sixth filtering cavity, 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 second direction.

3. The filter of claim 2,

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

4. The filter of claim 3, further comprising a flying bar and a support clamp, wherein the flying bar is fixed on the support clamp;

and the flying rod is arranged between the sixth filtering cavity and the eighth filtering cavity of the filtering branch circuit so as to realize capacitive cross coupling.

5. The filter of claim 3, further comprising a metal coupling rib,

and the metal coupling rib is arranged between the eighth filtering cavity and the tenth filtering cavity of the filtering branch circuit so as to realize capacitive cross coupling.

6. The filter according to claim 1, wherein windows are disposed between two filter cavities sequentially coupled in the ten filter cavities of the filter branch, between the first filter cavity and the third filter cavity of the filter branch, and between the first filter cavity and the fourth filter cavity of the filter branch, so as to implement window coupling.

7. The filter of claim 6,

8. The filter of claim 1, wherein the filter cavity has an outer diameter in the range of 28mm to 32mm and a height in the range of 18mm to 22 mm.

9. The filter of claim 1, wherein the filter cavity is provided with a resonant rod and a tuning rod, the resonant rod is provided with a hollow inner cavity, and one end of the tuning rod is disposed in the hollow inner cavity for adjusting the resonant frequency of the filter cavity.

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.