CN113889727A - Communication device and filter thereof - Google Patents

Abstract

The application discloses communication equipment and wave filter thereof, this wave filter includes: a housing having a first direction and a second direction perpendicular to each other; the receiving filter branch is arranged on the shell and consists of eight filter cavities which are sequentially coupled to form three capacitive cross-coupling zeros of the receiving filter branch; and the transmitting and filtering branch is arranged on the shell and consists of eleven filtering cavities which are sequentially coupled to form four cross-coupling zero points of the transmitting and filtering branch, and the first filtering cavity to the eighth filtering cavity of the receiving and filtering branch, the second filtering cavity to the sixth filtering cavity of the transmitting and filtering branch and the eleventh filtering cavity of the transmitting and filtering branch are divided into three rows arranged along the first direction. Through the mode, the filter can realize zero point suppression, has strong out-of-band suppression performance, can reduce the size of the filter, and is beneficial to the miniaturization of the filter.

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 receiving filter branch is arranged on the shell and consists of eight filter cavities which are sequentially coupled to form three capacitive cross-coupling zeros of the receiving filter branch; and the transmitting and filtering branch is arranged on the shell and consists of eleven filtering cavities which are sequentially coupled to form four cross-coupling zero points of the transmitting and filtering branch, and the first filtering cavity to the eighth filtering cavity of the receiving and filtering branch, the second filtering cavity to the sixth filtering cavity of the transmitting and filtering branch and the eleventh filtering cavity of the transmitting and filtering branch are divided into three rows arranged along the first direction.

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, eight filter cavities of the receiving filter branch form three capacitive cross coupling zero points, eleven filter cavities of the transmitting filter branch form four cross coupling zero points, zero point suppression can be realized, and the out-of-band suppression performance and the anti-interference capability are strong; the first filtering cavity to the eighth filtering cavity of the receiving filtering branch circuit, the second filtering cavity to the sixth filtering cavity of the transmitting filtering branch circuit and the eleventh filtering cavity of the transmitting filtering branch circuit are divided into three rows arranged along the first direction, the filtering 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.

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;

figure 2 is a schematic diagram of the structure of one embodiment of a first metal resonator rod and tuning rod of the filter of figure 1;

figure 3 is a schematic diagram of the structure of the metal resonating bar and the tuning bar of the filter of figure 1;

figure 4 is a schematic diagram of the structure of the dielectric resonator rod and the tuning rod of the filter of figure 1;

FIG. 5 is a schematic diagram of the topology of the receive filter branch of the filter of FIG. 1;

FIG. 6 is a schematic diagram of the topology of the transmit filter branch of the filter of FIG. 1;

FIG. 7 is a schematic diagram of the equivalent circuit of the filter of FIG. 1;

FIG. 8 is a diagram showing simulation results of the filter of FIG. 1;

fig. 9 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 work 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, a receiving filter branch 12 and a transmitting filter branch 13, 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 receiving filter branch 12 is disposed on the housing 11 and is composed of eight filter cavities coupled in sequence; the eight filter cavities for receiving the filter branch circuit 12 are a first filter cavity a1, a second filter cavity a2, a third filter cavity A3, a fourth filter cavity a4, a fifth filter cavity a5, a sixth filter cavity a6, a seventh filter cavity a7 and an eighth filter cavity A8 for receiving the filter branch circuit 12. Namely, the receiving filter branch 12 is composed of an eighth-order filter cavity, and three capacitive cross-coupling zeros are formed, so that the out-of-band rejection performance of the receiving filter branch 12 is improved.

The emission filtering branch 13 is also arranged on the housing 11 and is composed of eleven filtering cavities coupled in sequence, and the eleven filtering cavities of the emission filtering branch 13 are a first filtering cavity B1, a second filtering cavity B2, a third filtering cavity B3, a fourth filtering cavity B4, a fifth filtering cavity B5, a sixth filtering cavity B6, a seventh filtering cavity B7, an eighth filtering cavity B8, a ninth filtering cavity B9, a tenth filtering cavity B10 and an eleventh filtering cavity B11 of the emission filtering branch 13.

As shown in fig. 1, the projection of the receiving filter branch 12 and the transmitting filter branch 13 in the second direction L2 are overlapped, so as to fully utilize the space of the housing 11 and reduce the size of the filter.

Further, as shown in fig. 1, the first to eighth filter cavities a1 to A8 of the receiving filter branch 12, the second to sixth filter cavities B2 to B6 of the transmitting filter branch 13, and the eleventh filter cavity B11 of the transmitting filter branch 13 are divided into three 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 receiving 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 and the eighth filtering cavity A8 of the receiving filtering branch 12 are in a row and are sequentially arranged along the second direction L2; the second filtering cavity B2, the third filtering cavity B3, the fourth filtering cavity B4, the fifth filtering cavity B5, the sixth filtering cavity B6 and the eleventh filtering cavity B11 of the emission filtering branch 13 are in a row and are sequentially arranged along the second direction L2. The sixth filtering cavity B6 and the seventh filtering cavity B7 of the transmitting filtering branch 13 are symmetrical to the eleventh filtering cavity B11 and the tenth filtering cavity B10 of the transmitting filtering branch 13 along the central connecting line of the eighth filtering cavity B8 and the ninth filtering cavity B9 of the transmitting filtering branch 13. 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, the size of the filter can be reduced, and the requirement of 5G miniaturization is met.

The eight filter cavities a1-A8 of the receiving filter branch 12 may be first metal filter cavities, specifically, the diameter range of the first metal filter cavities is 20-24mm, and the height range of the first metal filter cavities is 41-45 mm.

As shown in fig. 1, a first metal resonant rod 14 and a tuning rod 15 are disposed in the first metal filter cavity, as shown in fig. 2, fig. 2 is a schematic structural diagram of the first metal resonant rod 14 and the tuning rod 15 in fig. 1, the first metal resonant rod 14 is provided with a first hollow inner cavity (not labeled in the figure), and one end of the tuning rod 15 is disposed in the first hollow inner cavity for adjusting a resonant frequency of the first metal filter cavity. The first metal resonance rod 14 includes a first turn-up 141 and a first resonance column 142, the first turn-up 141 has a diameter larger than that of the first resonance column 142, and the first turn-up 141 is located at one end of the first resonance column 142. Among them, the first turning plate 141 and the first resonant post 142 may be integrally formed to make the design simpler. The first metal resonance rod 14 in this embodiment uses a tape reel structure, and the signal coupling amount of the first metal resonance rod 14 can be increased. The first metal resonant rod 14 may be 304 stainless steel to improve the stability of the filter. In other embodiments, the material of the first metal resonant rod 14 may also be the slitted 1215 MS. Of course, in other embodiments, the first metal resonant rod 14 may also be an M8 or M4 screw rod, and is made of copper or silver. In this embodiment, the first metal resonant rod 14, the first hollow cavity and the tuning rod 15 may be coaxially disposed.

The eight filter cavities a1-A8 of the receiving filter branch 12 may be of the same size and material to improve filter uniformity.

Optionally, the eleven filter cavities B1-B11 of the transmitting filter branch 13 may be metal filter cavities or dielectric filter cavities. And a metal resonance rod is arranged in the metal filter cavity, and a medium resonance rod is arranged in the medium filter cavity. In particular, the type of filter cavity may be selected according to the magnitude of the power of each filter cavity, such as a dielectric filter cavity when the power of the filter cavity is large and a metal filter cavity when the power of the filter cavity is small.

In this embodiment, the first filtering cavity B1, the second filtering cavity B2, the third filtering cavity B3, the fourth filtering cavity B4, the fifth filtering cavity B5, the sixth filtering cavity B6, the eighth filtering cavity B8, and the eleventh filtering cavity B11 of the transmitting filtering branch 13 are metal resonant cavities, and the seventh filtering cavity B7, the ninth filtering cavity B9, and the tenth filtering cavity B10 of the transmitting filtering branch 13 are dielectric resonant cavities, so that the filter meets the design requirements, and the size of the filter can be reduced.

Specifically, the diameter range of the metal filter cavity is 29-33mm, and the height range of the metal filter cavity is 41-45 mm. The diameter range of the medium resonant cavity is 29-33mm, and the height range of the medium filter cavity is 41-45 mm. That is, the volume of the filter cavity in this embodiment is small, so that the weight of the filter can be reduced, the miniaturization of the filter is facilitated, and the requirement of 5G miniaturization can be met.

As shown in fig. 1, a metal resonance rod 16 and a tuning rod 15 are disposed in the metal filter cavity, as shown in fig. 3, fig. 3 is a schematic structural diagram of the metal resonance rod 16 and the tuning rod 15 in fig. 1, and the metal resonance rod 16 is provided with a hollow inner cavity (not labeled in the figure) in which one end of the tuning rod 15 is disposed for adjusting the resonance frequency of the metal filter cavity. The metal resonance rod 16 comprises a turning plate 161 and a resonance column 162, the diameter of the turning plate 161 is larger than that of the resonance column 162, the turning plate 161 is arranged at one end of the resonance column 162, and the turning plate 161 and the resonance column 162 can be integrally formed, so that the design is simpler. The metal resonant rod 16 may be 304 stainless steel to improve the stability of the filter. In other embodiments, the material of the metal resonant rod 16 may be the slitted 1215 MS. Of course, in other embodiments, the metal resonant rod 16 may be an M8 or M4 screw rod, and may be made of copper or silver. In this embodiment, the metal resonance rod 16, the hollow cavity and the tuning rod 15 may be coaxially disposed.

As shown in fig. 1, a dielectric resonance rod 17 and a resonance rod 15 are disposed in the dielectric filter cavity, and as shown in fig. 4, fig. 4 is a schematic structural view of the dielectric resonance rod 17 and the resonance rod 15 in fig. 1. The dielectric resonance rod 17 is provided with a receiving space (not shown) in which one end of the resonance rod 15 is disposed, and the dielectric resonance rod 17 is formed by combining a dielectric and a metal. In this embodiment, the dielectric resonant rod 17 includes a metal part 171 and a dielectric disc 172, the metal part 171 is connected to the dielectric disc 172, wherein the metal part 171 may be made of iron, and the dielectric disc 172 may be made of ceramic. Preferably, the dielectric disc 172 is made of ceramic with a dielectric constant of 23 to improve the stability of the filter. In other embodiments, the material of the metal portion 171 may be silver, copper, aluminum, titanium, gold, or the like. In this embodiment, the dielectric resonance rod 17, the accommodating space and the resonance rod 15 may be coaxially disposed.

Further, the filter further includes a cover plate (not shown) covering the filter cavities a1-a9 and B1-B11, and the other end of the tuning rod 15 is inserted into the cover plate, wherein the tuning rod 15 may be a metal screw.

First windows (not marked in the figure) are arranged between two sequentially coupled filter cavities in the eight filter cavities A1-A8 of the receiving filter branch 12 and between two sequentially coupled filter cavities in the eleven filter cavities B1-B11 of the transmitting filter branch 13, and electromagnetic energy is transmitted between the two sequentially coupled filter cavities through the first windows.

As shown in fig. 1, in order to improve the coupling strength between two adjacent filter cavities on the main coupling path, a second metal coupling rib 18 may be further provided, for example, the second metal coupling rib 18 may be respectively provided between the first filter cavity B1 and the second filter cavity B2 of the transmitting filter branch 13, between the sixth filter cavity B6 and the seventh filter cavity B7, between the seventh filter cavity B7 and the eighth filter cavity B8, between the tenth filter cavity B10 and the eleventh filter cavity B11, between the sixth filter cavity A6 and the seventh filter cavity a7, and between the seventh filter cavity a7 and the eighth filter cavity A8 of the receiving filter branch 12, so as to increase the coupling strength. In other embodiments, the second metal coupling rib 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, and the like of the receiving filter branch 12 according to actual situations.

As shown in fig. 1 and fig. 5, fig. 5 is a schematic topology diagram of the receiving filter branch 12 in fig. 1, a capacitive cross coupling exists between the first filter cavity a1 and the third filter cavity A3 of the receiving filter branch 12, an inductive cross coupling exists between the first filter cavity a1 and the fourth filter cavity a4, the two sets of cross couplings are combined together to form two capacitive cross coupling zeros, and in addition, a capacitive cross coupling exists between the sixth filter cavity a6 and the eighth filter cavity A8, so that the three capacitive cross coupling zeros of the receiving filter branch 12 are formed, the out-of-band rejection performance of the receiving filter branch 12 is improved, and the receiving filter branch has strong anti-interference capability, and ensures that the communication system is not interfered by spurious 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.

As shown in fig. 1 and fig. 6, fig. 6 is a schematic topological structure diagram of the transmitting filter branch 13 in fig. 1, wherein the third filter cavity B3 and the fifth filter cavity B5 of the transmitting filter branch 13 are capacitively cross-coupled, the sixth filter cavity B6 and the eighth filter cavity B8 of the transmitting filter branch 13 are capacitively cross-coupled, the eighth filter cavity B8 and the tenth filter cavity B10 of the transmitting filter branch 13 are inductively cross-coupled, and the eighth filter cavity B8 and the eleventh filter cavity B11 of the transmitting filter branch 13 are inductively cross-coupled, so as to form four cross-coupling zeros of the transmitting filter branch 13, improve the out-of-band rejection performance of the filter, and ensure that the communication system is not interfered by the stray signals.

As shown in fig. 1, the filter further includes a flying rod 19, and in this embodiment, the flying rod 19 is disposed between the first filter cavity a1 and the third filter cavity A3 of the receiving filter branch 12, between the sixth filter cavity a6 and the eighth filter cavity A8 of the receiving filter branch 12, and between the sixth filter cavity B6 and the eighth filter cavity B8 of the transmitting filter branch 13, so as to implement capacitive cross coupling. In a particular embodiment, the flying bar 19 comprises: the coupling probe is fixed on the supporting clamping seat; wherein the support clamp may be disposed at a window (not shown) between the two filter cavities that are cross-coupled. Alternatively, the coupling probe is a metal probe, and the material of the support holder may be PTFE (polytetrafluoroethylene) or engineering plastic.

Further, as shown in fig. 1, the filter further includes a metal plate 20, both ends of the metal plate 20 are provided with an insulating spacer (not shown), and the metal plate 20 and the insulating spacer are provided between the third filter cavity B3 and the fifth filter cavity B5 of the transmitting filter branch 13, so as to implement capacitive cross coupling between the third filter cavity B3 and the fifth filter cavity B5 of the transmitting filter branch 13. The metal sheet 20 may be copper, iron, etc., and the insulating spacer may be a plastic spacer.

As shown in fig. 1, a second window (not labeled) is disposed between the first filter cavity a1 and the fourth filter cavity a4 of the receiving filter branch 12, so as to implement the inductive cross coupling between the first filter cavity a1 and the fourth filter cavity a4 of the receiving filter branch 12. Third windows (not marked in the figure) are arranged between the eighth filtering cavity B8 and the tenth filtering cavity B10 of the emission filtering branch 13 and between the eighth filtering cavity B8 and the eleventh filtering cavity B11, and first metal coupling ribs 21 are further arranged between the eighth filtering cavity B8 and the tenth filtering cavity B10 of the emission filtering branch 13, so that inductive cross coupling between the eighth filtering cavity B8 and the tenth filtering cavity B10 of the emission filtering branch 13 and between the eighth filtering cavity B8 and the eleventh filtering cavity B11 is realized.

The filter further includes a low pass filter unit 22, a first port (not shown), a second port (not shown), and a third port (not shown), the first filter cavity a1 of the receiving filter branch 12 is connected to the first port, the eighth filter cavity A8 of the receiving filter branch 12 is connected to the second port, the first filter cavity B1 of the transmitting filter branch 13 is connected to the first port, and the eleventh filter cavity B11 of the transmitting filter branch 13 is connected to the third port through the low pass filter unit 22, wherein the first port, the second port, and the third port may be taps of the filter. The low pass filter unit 22 may include a plurality of low pass filters (not shown) arranged in series for improving the far end performance of the filter.

In this embodiment, the receiving filtering branch 12 and the transmitting filtering branch 13 share the first port, so that the number of taps can be reduced, the number of taps of the filter can be reduced, the space occupied by the taps of the filter can be reduced, the size of the filter can be reduced, and the cost can be reduced.

The equivalent circuit of the filter of this embodiment is shown in fig. 7, and the circuit model includes a filter cavity a1-A8, a filter cavity B1-B11 and an impedance transformer 71, wherein 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, in the receiving filtering branch 12, impedance changers 71 are required to be arranged between the first port and the first filtering cavity a1 of the receiving filtering branch 12, between adjacent filtering cavities on the main coupling path of the receiving filtering branch 12, between non-cascaded filtering cavities forming cross coupling, and between the eighth filtering cavity A8 and the second port of the receiving filtering branch 12, so that the impedance of each filtering cavity in the receiving filtering branch 12 matches the impedance of the transmission link to realize signal transmission. In the transmitting filter branch 13, it is necessary to provide an impedance changer 71 between the first port and the first filter cavity B1 of the transmitting filter branch 13, between adjacent filter cavities on the main coupling path of the transmitting filter branch 13, between non-cascaded filter cavities forming cross coupling, and between the eleventh filter cavity B11 and the third port of the transmitting filter branch 13, so that the impedance passing through each filter cavity in the transmitting filter branch 13 matches the impedance of the transmission link to realize signal transmission.

As shown in fig. 8, fig. 8 is a schematic diagram of simulation results of the filter of the present application, and the simulation bandwidth of the transmitting filter branch 13 is shown as a frequency band curve 81 in fig. 8, and it can be seen from the simulation diagram that the bandwidth of the transmitting filter branch 13 is located in a range from 791MHz to 821MHz, which meets the design requirement of the filter, and can accurately control the bandwidth of the transmitting filter branch 13. The suppression of the frequency point 790MHz (m31) is-13.588 dB, the suppression of the frequency point 821MHz (m30) is-2.23 dB, the suppression of the frequency point 791MHz (m29) is-2.465 dB, and the suppression of the frequency point 832MHz (m35) is-124.67 dB, so that the filter has small in-band loss (less than 1.4dB) and has strong anti-interference capability (the suppression of the 1MHz outside a passband is more than 9 dB).

The simulation bandwidth of the receiving and filtering branch 12 is shown as a frequency band curve 82 in fig. 8, and it can be seen from the simulation diagram that the bandwidth of the receiving and filtering branch 12 is in the range of 832MHz-862MHz, which meets the design requirement of the filter, and can accurately control the bandwidth of the receiving and filtering branch 12. The suppression of a frequency point 832MHz (m32) is-1.42 dB, the suppression of a frequency point 862MHz (m33) is-1.057 dB, and the suppression of a frequency point 821MHz (m34) is-92.448 dB, so that the filter has small in-band loss (less than 1.4dB) and has the performance of strong anti-interference capability (the suppression of 1MHz outside a passband is more than 9 dB).

The filter of the embodiment is a duplexer applied to a 5G mobile communication system, the working frequency band of the receiving filtering branch 12 is 832MHz-862MHz, the working frequency band of the transmitting filtering branch 13 is 791MHz-821MHz, and the filter has the characteristics of small in-band loss, strong anti-jamming capability and large power capacity (the bearing power at normal temperature and normal pressure is more than 160W).

In summary, in the filter provided by this embodiment, the receiving filtering branch 12 is designed by combining eight-order filtering cavities, the transmitting filtering branch 13 is designed by combining eleven-order filtering cavities, the filtering cavities are arranged regularly, the size of the filter is reduced, and the filter design scheme is simple, so the design cost can be reduced; and a transmission zero structure is introduced into the receiving filtering branch 12 and the transmitting filtering branch 13, so that zero suppression can be realized, the filter has strong anti-interference capability, the 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. 9, fig. 9 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 receiving filter branch is arranged on the shell and consists of eight filter cavities which are sequentially coupled to form three capacitive cross-coupling zeros of the receiving filter branch;

the transmitting and filtering branch is arranged on the shell and consists of eleven filtering cavities which are sequentially coupled to form four cross-coupling zero points of the transmitting and filtering branch;

the first filtering cavity to the eighth filtering cavity of the receiving filtering branch, the second filtering cavity to the sixth filtering cavity of the transmitting filtering branch and the eleventh filtering cavity of the transmitting filtering branch are divided into three 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 receiving 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 and the eighth filtering cavity of the receiving filtering branch are in a row and are sequentially arranged along the second direction;

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

and the sixth filtering cavity and the seventh filtering cavity of the emission filtering branch circuit and the eleventh filtering cavity and the tenth filtering cavity of the emission filtering branch circuit are symmetrical along the central connecting line of the eighth filtering cavity and the ninth filtering cavity of the emission filtering branch circuit.

3. The filter according to claim 2, wherein the first, second, third, fourth, fifth, sixth, eighth and eleventh filter cavities of the transmitting filter branch are metal filter cavities, and the seventh, ninth and tenth filter cavities of the transmitting filter branch are dielectric filter cavities, wherein a metal resonance rod is disposed in the metal filter cavities, and a dielectric resonance rod is disposed in the dielectric filter.

4. The filter of claim 2,

the first filter cavity and the third filter cavity of the receiving filter branch are capacitively and cross-coupled, the first filter cavity and the fourth filter cavity of the receiving filter branch are inductively and cross-coupled, and the sixth filter cavity and the eighth filter cavity of the receiving filter branch are capacitively and cross-coupled to form three capacitive cross-coupling zeros of the receiving filter branch;

capacitive cross coupling is respectively performed between the third filtering cavity and the fifth filtering cavity of the transmitting filtering branch, between the sixth filtering cavity and the eighth filtering cavity of the transmitting filtering branch, and inductive cross coupling is respectively performed between the eighth filtering cavity and the tenth filtering cavity of the transmitting filtering branch, and between the eighth filtering cavity and the eleventh filtering cavity of the transmitting filtering branch, so as to form four cross coupling zeros of the transmitting filtering branch.

5. The filter according to claim 4, wherein first windows are disposed between two sequentially coupled filter cavities of the eight filter cavities of the receiving filter branch and between two sequentially coupled filter cavities of the eleven filter cavities of the transmitting filter branch, so as to implement window coupling.

6. The filter according to claim 5, wherein a second window is disposed between the first filter cavity and the fourth filter cavity of the receiving filter branch to achieve inductive cross coupling between the first filter cavity and the fourth filter cavity of the receiving filter branch, third windows are disposed between the eighth filter cavity and the tenth filter cavity of the transmitting filter branch, and between the eighth filter cavity and the eleventh filter cavity of the transmitting filter branch, and a first metal coupling rib is further disposed between the eighth filter cavity and the tenth filter cavity of the transmitting filter branch to achieve inductive cross coupling between the eighth filter cavity and the tenth filter cavity of the transmitting filter branch, and between the eighth filter cavity and the eleventh filter cavity of the transmitting filter branch.

7. The filter of claim 4, further comprising a coupling probe and a support socket, the coupling probe being fixed to the support socket; the coupling probes are arranged between the first filter cavity and the third filter cavity of the receiving filter branch, between the sixth filter cavity and the eighth filter cavity of the receiving filter branch and between the sixth filter cavity and the eighth filter cavity of the transmitting filter branch, so as to realize capacitive cross coupling between the first filter cavity and the third filter cavity of the receiving filter branch, between the sixth filter cavity and the eighth filter cavity of the receiving filter branch and between the sixth filter cavity and the eighth filter cavity of the transmitting filter branch;

the filter further comprises a metal sheet, insulating gaskets are arranged at two ends of the metal sheet, and capacitive cross coupling between the third filtering cavity and the fifth filtering cavity of the transmitting filtering branch is achieved.

8. The filter according to claim 2, wherein second metal coupling ribs are disposed between the sixth filter cavity and the seventh filter cavity of the receiving filter branch, between the seventh filter cavity and the eighth filter cavity of the receiving filter branch, between the first filter cavity and the second filter cavity of the transmitting filter branch, between the sixth filter cavity and the seventh filter cavity of the transmitting filter branch, between the seventh filter cavity and the eighth filter cavity of the transmitting filter branch, and between the tenth filter cavity and the eleventh filter cavity of the transmitting filter branch.

9. The filter according to any one of claims 1-8,

the bandwidth range of the transmitting filtering branch circuit is as follows: 791MHz-821 MHz;

the bandwidth range of the receiving filtering branch circuit is as follows: 832MHz-862 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 radio frequency signals.

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