CN113629370A - Communication device and filter thereof - Google Patents

Abstract

The application discloses a communication device and a filter thereof. The filter includes: the filter branch is arranged on the shell and consists of ten filter cavities which are sequentially coupled, and the ten filter cavities of the filter branch form three capacitive cross coupling zero points and two inductive cross coupling zero points; the second filtering cavity and the fifth filtering cavity of the filtering branch circuit are in capacitive cross coupling, the third filtering cavity and the fifth filtering cavity are in capacitive cross coupling, the sixth filtering cavity and the eighth filtering cavity are in capacitive cross coupling, the fifth filtering cavity and the eighth filtering cavity are in inductive cross coupling, and the eighth filtering cavity and the tenth filtering cavity are in inductive cross coupling; the first to tenth filter cavities of the filter branch are divided into three rows arranged along the first direction. Through the mode, zero point suppression can be realized, 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.

In the prior art, the filter realizes 2600MHz high frequency, is large in size and cannot meet the requirement of 5G miniaturization.

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 filter branch is arranged on the shell and consists of ten filter cavities which are sequentially coupled, and the ten filter cavities of the filter branch form three capacitive cross coupling zero points and two inductive cross coupling zero points, wherein the second filter cavity and the fifth filter cavity of the filter branch are capacitively cross coupled, 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, the fifth filter cavity and the eighth filter cavity of the filter branch are inductively cross coupled, and the eighth filter cavity and the tenth filter cavity of the filter branch are inductively cross coupled; the first to tenth filter cavities of the filter branch are divided into three rows arranged along the first direction.

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

The filter also comprises a coupling probe and a supporting clamping seat, wherein the coupling probe is fixed on the supporting clamping seat; coupling probes are arranged between the second filtering cavity and the fifth filtering cavity of the filtering branch, between the third filtering cavity and the fifth filtering cavity of the filtering branch and between the sixth filtering cavity and the eighth filtering cavity of the filtering branch, so that capacitive cross coupling between the second filtering cavity and the fifth filtering cavity, between the third filtering cavity and the fifth filtering cavity and between the sixth filtering cavity and the eighth filtering cavity of the filtering branch is achieved respectively.

And windows are arranged between the two sequentially coupled filtering cavities of the filtering branch circuit, between the fifth 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 window coupling.

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 coupling bandwidths between the two filter cavities, between the fifth filter cavity and the eighth filter cavity of the filter branch circuit and between the eighth filter cavity and the tenth filter cavity of the filter branch circuit which are sequentially coupled.

Wherein the diameter of the filter cavity is less than or equal to 21 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.

The bandwidth range of the filtering branch circuit is 2515MHz to 2675 MHz.

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 the above embodiment, and is configured to filter a radio frequency signal.

Different from the situation of the prior art, in the application, capacitive cross coupling exists between the second filter cavity and the fifth filter cavity of the filter branch, capacitive cross coupling exists between the third filter cavity and the fifth filter cavity of the filter branch, capacitive cross coupling exists between the sixth filter cavity and the eighth filter cavity of the filter branch, inductive cross coupling exists between the fifth filter cavity and the eighth filter cavity of the filter branch, and inductive cross coupling exists between the eighth filter cavity and the tenth filter cavity of the filter branch to form five cross coupling zeros so as to form three capacitive cross coupling zeros and two inductive cross coupling zeros, so that zero suppression can be realized and the filter has strong out-of-band suppression performance; ten filter chambers of the filter branch circuit are divided into three rows arranged along the first direction, the filter chambers 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.

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 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.

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 three columns arranged in the first direction L1. Specifically, the first filter cavity a1, the second filter cavity a2, the tenth filter cavity a10 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 third filtering cavity A3, the fifth filtering cavity a5 and the eighth filtering cavity A8 of the filtering branch 12 are in a row and are sequentially arranged along the second direction L2; the fourth filter cavity a4, the sixth filter cavity a6 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 filter cavities of the filter of the 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, each of the ten filter cavities a1-a10 of the filter branch 12 may be 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.

As shown in fig. 2, the resonant rod 13 includes a turn-up 131 and a resonant post 132, the turn-up 131 has a diameter larger than that of the resonant post 132, the turn-up 131 is located at one end of the resonant post 132, and the turn-up 131 and the resonant post 132 may be integrally formed to make the design simpler. In the present embodiment, the resonance rod 13 uses a tape reel structure, and the signal coupling amount of the resonance rod 13 can be increased. The resonant rod 13, the hollow cavity and the tuning rod 14 of the present embodiment are coaxially disposed.

The filtering cavity of the embodiment can be a metal filtering cavity, the diameter of the metal filtering cavity is smaller than or equal to 21mm, and the filter has small overall size and light weight while meeting the design requirements. 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 material of the resonant rod 13 is 45 steel to improve the stability of the filter.

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.

Optionally, the size of the ten filter cavities a1-a10 may also be the same to improve the uniformity of the filter.

As shown in fig. 1, ten filter cavities a1-a10 of the filter branch 12 are sequentially and adjacently arranged along the main coupling path, and a window (not shown) is disposed between two adjacent filter cavities (i.e., in a cascade arrangement) along the main coupling path, so as to implement window coupling. And electromagnetic energy is transmitted between two adjacent filter cavities on the main coupling path through the window.

As shown in fig. 1, the filter of the present embodiment further includes a plurality of adjustment screws 15. In order to adjust the coupling strength between two adjacent filter cavities on the main coupling path, the adjusting screw 15 may be disposed at the above-mentioned window, for example, the adjusting screw 15 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 a9 and the tenth filter cavity a 10.

Further, 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, where ten filtering cavities a1-a10 of the filtering branch 12 form five cross-coupling zeros of the filtering branch 12, specifically, a capacitive cross-coupling is performed between the second filtering cavity a2 and the fifth filtering cavity a5 of the filtering branch 12, a capacitive cross-coupling is performed between the third filtering cavity A3 and the fifth filtering cavity a5, so that two transmission zeros are generated at two ends of the pass band, an inductive cross-coupling is performed between the fifth filtering cavity a5 and the eighth filtering cavity A8 of the filtering branch 12, and a capacitive cross-coupling is performed between the sixth filtering cavity a6 and the eighth filtering cavity A8, so that two transmission zeros are generated at a low end of the pass band; the eighth filter cavity A8 and the tenth filter cavity a10 of the filtering branch 12 are inductively cross-coupled to generate a transmission zero at the high end of the pass band, so as to achieve the function of stop band rejection, improve the rejection performance of the filter band, and prevent the communication system from being interfered by stray signals.

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.

Further, as shown in fig. 1, the filter further includes a flying rod 17, and in this embodiment, the flying rod 17 is disposed between the second filter cavity a2 and the fifth filter cavity a5, between the third filter cavity A3 and the fifth filter cavity a5, and between the sixth filter cavity a6 and the eighth filter cavity A8 of the filter branch 12, so as to implement capacitive cross coupling. As shown in fig. 4, fig. 4 is a schematic structural diagram of an embodiment of the flying bar 17 in fig. 1, and the flying bar 17 includes: a coupling probe 171 and a supporting clamp 172, the coupling probe 171 being fixed on the supporting clamp 172; wherein the support clamp 172 may be disposed at a window (not shown) between two filter cavities that are cross-coupled. Alternatively, the coupling probe 171 may be a metal probe, and the coupling probe 171 may be cylindrical in shape to improve the stability of the filter; the material of the support holder 172 may be PTFE (polytetrafluoroethylene) or engineering plastic. Optionally, adjusting screws 15 may be further disposed between the second filter cavity a2 and the fifth filter cavity a5, between the third filter cavity A3 and the fifth filter cavity a5, and between the sixth filter cavity a6 and the eighth filter cavity A8, for adjusting the coupling strength between the two filter cavities of capacitive cross coupling. The capacitive cross coupling structure is simple, convenient to machine and capable of saving cost.

Further, as shown in fig. 1, the present embodiment respectively arranges windows between the fifth filter cavity a5 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 realize the inductive cross coupling between the fifth filter cavity a5 and the eighth filter cavity A8 and the inductive cross coupling between the eighth filter cavity A8 and the tenth filter cavity a 10. The embodiment realizes the inductive cross coupling by opening the window, has a simple design scheme, and can reduce the cost of the filter.

The filter may further include 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 tenth filter cavity a10 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 tenth filter chamber a10, and outputs an electromagnetic signal in the tenth filter chamber a 10.

The equivalent circuit of the filter of this embodiment is shown in fig. 5, and the circuit model includes a filter cavity a1-a10 and an impedance transformer 51, 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, it is necessary to provide impedance changers 51 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 tenth filter cavity a10 and the second port, so that the impedance through each filter cavity matches 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 601 in fig. 6, and it can be seen from the simulation diagram that the bandwidth of the filtering branch 12 is located in a range of 2515MHz to 2675MHz, which meets the design requirement of the filter and can accurately control the bandwidth of the filtering branch 12. The suppression of a frequency point 2515MHz (m1) is-1.333 dB, the suppression of a frequency point 2675MHz (m2) is-1.018 dB, the suppression of a frequency point 2500MHz (m3) is-63.637 dB, and the suppression of a frequency point 2700MHz (m4) is-67.999 dB, so that the filter has small in-band loss (less than 2.0dB) and strong anti-interference capability (the suppression of 15MHz at the lower end outside a passband is greater than 45dB, and the suppression of 25MHz at the higher end outside the passband is greater than 45 dB).

The filter of the embodiment is a ten-order microwave filter applied to a 5G mobile communication system, the working frequency band of the filter is 2515 MHz-2675 MHz, and the filter has the characteristics of small in-band loss, wide bandwidth (160M) and strong anti-interference capability.

In summary, the filter provided in this embodiment is designed by combining ten-order filter cavities, the first filter cavity a1 to the tenth filter cavity a10 of the filter branch 12 are divided into three rows arranged along the first direction L1, the filter design is simple, and the cavity arrangement is regular, so that the design cost can be reduced, and the volume of the filter can be reduced; ten filter cavities of the filter branch circuit 12 form three capacitive cross coupling zero points and two inductive cross coupling zero points, so that zero point suppression can be realized, the filter has strong anti-interference capability, a communication system is not interfered by stray signals, and the use of the latest 5G mobile communication system can be met.

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).

It should be noted that some embodiments of the present application refer to the present application as a filter, and may also be referred to as a combiner, that is, a dual-band combiner, and may also be referred to as a duplexer in other embodiments.

The 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 filter branch is arranged on the shell and consists of ten filter cavities which are sequentially coupled, and the ten filter cavities of the filter branch form three capacitive cross coupling zero points and two inductive cross coupling zero points, wherein the second filter cavity and the fifth filter cavity of the filter branch are capacitively cross coupled, 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, the fifth filter cavity and the eighth filter cavity of the filter branch are inductively cross coupled, and the eighth filter cavity and the tenth filter cavity of the filter branch are inductively cross coupled;

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

2. The filter of claim 1,

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

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

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

3. The filter of claim 2, further comprising a coupling probe and a support socket, wherein the coupling probe is fixed to the support socket;

the coupling probe is arranged between the second filtering cavity and the fifth filtering cavity of the filtering branch circuit and between the third filtering cavity and the fifth filtering cavity of the filtering branch circuit and between the sixth filtering cavity and the eighth filtering cavity of the filtering branch circuit, so as to respectively realize capacitive cross coupling between the second filtering cavity and the fifth filtering cavity of the filtering branch circuit, between the third filtering cavity and the fifth filtering cavity and between the sixth filtering cavity and the eighth filtering cavity.

4. The filter according to claim 1, wherein windows are disposed between two sequentially coupled filter cavities of the filter branch, between the fifth filter cavity and the eighth filter cavity of the filter branch, and between the eighth filter cavity and the tenth filter cavity of the filter branch, so as to implement window coupling.

5. The filter according to claim 4, further comprising an adjusting screw, wherein the window is provided with the adjusting screw, and the adjusting screw is used for adjusting coupling bandwidths between the two sequentially coupled filter cavities, between a fifth filter cavity and an eighth filter cavity of the filter branch, and between the eighth filter cavity and a tenth filter cavity of the filter branch.

6. The filter according to claim 1, characterized in that the diameter of the filter cavity is less than or equal to 21 mm.

7. 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.

8. The filter of claim 7, wherein the resonant rod comprises a resonant post and a flap, the flap being located at one end of the resonant post.

9. The filter according to any of claims 1-8, characterized in that the bandwidth of the filtering branches ranges from 2515MHz to 2675 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.

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