CN212323180U - Communication device and filter thereof - Google Patents

Abstract

The application discloses a communication device and a filter thereof. 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 and consists of eleven filtering cavities which are sequentially coupled to form three capacitive cross coupling zero points, and the bandwidth range of the filtering branch is 925 MHz-960 MHz; the first to eleventh filter cavities of the filter branch are divided into two rows arranged along the first direction. By the mode, the filter is simple in design scheme, zero suppression can be achieved, the suppression effect of the filtering branch is improved, and debugging indexes are 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, strong adjustability, high Q value, stable electrical property, good heat dissipation performance and the like.

The inventor of the present application finds, in long-term research and development work, that a filter in the prior art is designed to achieve a frequency of 900MHz, the design scheme is complex, the performance such as out-of-band rejection is poor, and the anti-interference capability is weak.

SUMMERY OF THE UTILITY MODEL

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 and consists of eleven filtering cavities which are sequentially coupled to form three capacitive cross coupling zero points, and the bandwidth range of the filtering branch is 925 MHz-960 MHz; the first to eleventh filter cavities of the filter branch are divided into two rows arranged along the first direction.

The fourth filtering cavity, the seventh filtering cavity and the ninth filtering cavity of the filtering branch are in a row and are sequentially arranged along the second direction; the first filtering cavity, the second filtering cavity, the third filtering cavity, the fifth filtering cavity, the sixth filtering cavity, the eighth filtering cavity, the tenth filtering cavity and the eleventh filtering cavity of the filtering branch are in a row and are sequentially arranged along the second direction.

The third filtering cavity and the fifth filtering cavity of the filtering branch are in capacitive cross coupling, the sixth filtering cavity and the eighth filtering cavity of the filtering branch are in capacitive cross coupling, and the eighth filtering cavity and the tenth filtering cavity of the filtering branch are in capacitive cross coupling, so that three capacitive cross coupling zeros of the filtering branch are formed.

Wherein, the filter also comprises a flying rod; and flying rods are arranged between the third filtering cavity and the fifth filtering cavity of the filtering branch circuit, between the sixth filtering cavity and the eighth filtering cavity of the filtering branch circuit and between the eighth filtering cavity and the tenth filtering cavity of the filtering branch circuit so as to realize capacitive cross coupling.

And windows are arranged between the two sequentially coupled filtering cavities in the filtering branch circuit so as to realize window coupling.

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

Wherein the diameter range of the filter cavity is 31.5mm-35.5mm, and the height range of the filter cavity is 31mm-35 mm.

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.

Wherein, resonance pole includes resonance post and tilting disk, and the tilting disk is located the one end of resonance post.

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.

Different from the situation of the prior art, eleven filtering cavities of the filtering branch form three capacitive cross coupling zero points, so that the suppression effect of the filtering branch is improved while the bandwidth range of the filtering branch is 925 MHz-960 MHz, and the debugging index is facilitated; the filter only adopts capacitive cross coupling, thereby reducing the material types and being beneficial to processing; the first filtering cavity to the eleventh filtering cavity of the filtering branch circuit are divided into two rows arranged along the second direction, so that the design scheme of the filter is simple, and the size and the production cost of the filter are reduced.

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 diagram of the topology of the filtering branch of FIG. 1;

FIG. 4 is a schematic structural view of the fly rod of FIG. 1;

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

FIG. 6 is a diagram showing simulation results of the filter of FIG. 1;

fig. 7 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 eleven filtering cavities coupled in sequence, where the eleven 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, a tenth filtering cavity a10 and an eleventh filtering cavity a11 of the filtering branch 12.

Further, as shown in fig. 1, the first through eleventh filter cavities a1 through a11 of the filter branch 12 are divided into two columns arranged in the first direction L1. Specifically, the fourth filter cavity a4, the seventh filter cavity a7 and the ninth filter cavity a9 of the filter branch 12 are in a row and are sequentially arranged along the second direction L2; the first filtering cavity a1, the second filtering cavity a2, the third filtering cavity A3, the fifth filtering cavity a5, the sixth filtering cavity a6, the eighth filtering cavity A8, the tenth filtering cavity a10 and the eleventh filtering cavity a11 of the filtering branch 12 are in a row and are sequentially arranged along the second direction L2. The filter cavities a1-a11 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, in which the eleven filter cavities a1-a11 of the filter branch 12 are respectively provided with a resonant rod 13 and a tuning rod 14, the resonant rod 13 forms a hollow inner cavity (not shown), and one end of the tuning rod 14 is disposed 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 resonant rod 13 can adopt a tilting tray structure to meet the requirements of low-frequency characteristics and high-power bearing. The resonant rod 13 comprises a turning plate 131 and a resonant column 132, the turning plate 131 is disposed at one end of the resonant column 132, and the turning plate 131 and the resonant column 132 can be integrally formed to increase the stability of the filter.

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.

The filter cavity of this embodiment can be the metal filter cavity, and the diameter scope of metal filter cavity is 31.5mm-35.5mm, preferred 33.5mm, and the high scope of filter cavity is 31mm-35mm, preferred 33mm, 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 eleven filter cavities a1-a11, and the other end of the tuning rod 14 penetrates the cover plate, wherein the tuning rod 14 may be a metal screw.

As shown in fig. 1, the first filtering cavity a1 to the eleventh filtering cavity a11 of the filtering branch 12 are sequentially and adjacently arranged along the main coupling path, and a window (not shown in the figure) is disposed between two adjacent filtering cavities (i.e. in a cascade arrangement) arranged along the main coupling path, so as to implement window coupling, wherein electromagnetic energy is transmitted between the two adjacent filtering cavities on the main coupling path through the window. The filter of the embodiment has good window coupling consistency, does not need other materials, reduces the cost and has good electrical property stability.

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 third filter cavity A3 and the fourth filter cavity a4, between the fourth filter cavity a4 and the fifth filter cavity a5, 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, between the ninth filter cavity a9 and the tenth filter cavity a10, and between the tenth filter cavity a10 and the eleventh filter cavity a11 of the filter branch 12, respectively, so as to increase the coupling strength. In other embodiments, the reinforcing ribs 18 may be selectively 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 fifth filter cavity a5 and the sixth filter cavity a6, and the like 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 (not labeled) for adjusting the coupling strength between the two coupled filter cavities, which may be disposed in the above-mentioned window, for example, the adjusting screws 10 may be 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, between the ninth filter cavity a 586 and the tenth filter cavity a10, and the eleventh filter cavity a 10.

As shown in fig. 1 and fig. 3, fig. 3 is a schematic diagram of a topology structure of the filter branch 12 in fig. 1, a capacitive cross coupling exists between the third filter cavity A3 and the fifth filter cavity a5 of the filter branch 12, a capacitive cross coupling exists between the sixth filter cavity a6 and the eighth filter cavity A8, and a capacitive cross coupling exists between the eighth filter cavity A8 and the tenth filter cavity a10, so that three capacitive cross coupling zeros are formed at the lower end of the pass band, thereby implementing a stop band rejection function and improving a rejection performance of the filter band. And the materials required by the cross coupling can be kept consistent in the application, so that the material types are reduced, the processing is convenient, the types of the used clamps are few, and the installation efficiency is improved.

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.

As shown in fig. 1, the filter further includes a flying bar 17, and the flying bar 17 is disposed between the third filter cavity A3 and the fifth filter cavity a5, 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 of the filter branch 12, so as to implement capacitive cross coupling, and form three capacitive cross coupling zeros of the filter branch 12.

Specifically, as shown in fig. 4, the flying bar 17 includes a first connecting portion 171, a second connecting portion 172, and a connecting rod 173, the first connecting portion 171 and the second connecting portion 172 are respectively located at opposite ends of the connecting rod 173, wherein the first connecting portion 171 and the second connecting portion 172 are symmetrically disposed with respect to a center line of the connecting rod 173. I.e. the flying bar 17 may be dumbbell-shaped to make the structure of the filter simpler.

Optionally, the filter further includes a first port (not shown) and a second port (not shown), the first filter cavity a1 of the filter branch 12 is connected to the first port, and the eleventh filter cavity a11 of the filter branch 12 is connected to the second port, wherein the first port and the second port may be taps of the filter.

The first port is connected with the first filter cavity A1 and inputs electromagnetic signals to the first filter cavity A1; the second port is connected to the eleventh filter chamber a11, and outputs an electromagnetic signal in the eleventh filter chamber a 11.

The equivalent circuit of the filter of this embodiment is shown in fig. 5, and the circuit model includes a filter cavity a1-a11 and an impedance transformer 41, the impedance at the first port is about 50 ohms, and the impedance at the second port 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 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 eleventh filter cavity a11 and the second port, so that the impedance passing through each filter cavity is matched with the impedance of the transmission link to realize signal transmission.

As shown in fig. 6, fig. 6 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. 6, and it can be seen from the simulation diagram that the bandwidth of the filtering branch 12 is within a range of 925MHz to 960MHz, 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 925MHz (m12) is-1.496 dB, the suppression of the frequency point 960MHz (m13) is-1.081 dB, the suppression of the frequency point 920MHz (m8) is-19.248 dB, the suppression of the frequency point 915MHz (m9) is-114.706 dB, the suppression of the frequency point 965.0MHz (m10) is-14.547 dB, the suppression of the frequency point 970MHz (m11) is-37.927 dB, so that the in-band loss of the filter is small (less than 1.2dB), and the filter has strong anti-jamming capability (suppression is more than 105dB in the range of 880 plus 915 MHz).

The filter of the embodiment can be an eleven-order microwave filter applied to a 5G mobile communication system, the working frequency band of the filter is 925 MHz-960 MHz, and the filter has the characteristics of small in-band loss, strong anti-interference capability, low temperature drift fluctuation and large power capacity (the bearing power at normal temperature and normal pressure is more than 2500W).

In summary, the filter provided by the embodiment is designed by combining eleven-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; eleven filtering cavities of the filtering branch circuit 12 form three capacitive cross coupling zero points, zero point inhibition can be realized, the filter has strong anti-interference capacity, the communication system is not interfered by stray signals, the use of the current latest 5G mobile communication system can be met, in addition, the filter only adopts capacitive cross coupling in the application, the material consistency is good, and the processing is convenient.

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 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 (10)

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 is arranged on the shell and consists of eleven filtering cavities which are sequentially coupled to form three capacitive cross coupling zero points, and the bandwidth range of the filtering branch is 925 MHz-960 MHz;

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

2. The filter of claim 1,

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

the first filtering cavity, the second filtering cavity, the third filtering cavity, the fifth filtering cavity, the sixth filtering cavity, the eighth filtering cavity, the tenth filtering cavity and the eleventh filtering cavity of the filtering branch are in a row and are sequentially arranged along the second direction.

3. The filter according to claim 2, wherein the third filter cavity and the fifth filter cavity of the filter branch are capacitively cross-coupled, the sixth filter cavity and the eighth filter cavity of the filter branch are capacitively cross-coupled, and the eighth filter cavity and the tenth filter cavity of the filter branch are capacitively cross-coupled, so as to form three capacitive cross-coupling zeros of the filter branch.

4. The filter of claim 3, further comprising a fly rod;

the flying rod is arranged between the third filtering cavity and the fifth filtering cavity of the filtering branch circuit, between the sixth filtering cavity and the eighth filtering cavity of the filtering branch circuit and between the eighth filtering cavity and the tenth filtering cavity of the filtering branch circuit, so that capacitive cross coupling is realized.

5. The filter according to claim 1, wherein a window is disposed between each of the two sequentially coupled filter cavities in the filter branch to implement window coupling.

6. The filter of claim 5,

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

7. The filter according to claim 1, wherein the filter cavity has a diameter in the range of 31.5mm-35.5mm and a height in the range of 31mm-35 mm.

8. 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.

9. The filter of claim 8, wherein the resonant rod comprises a resonant post and a flap, the flap being located at one end of the resonant post.

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.

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