CN113725574A

CN113725574A - Communication equipment and filter

Info

Publication number: CN113725574A
Application number: CN202010432338.XA
Authority: CN
Inventors: 刘建伟
Original assignee: Anhui Tatfook Technology Co Ltd
Current assignee: Anhui Tatfook Technology Co Ltd
Priority date: 2020-05-20
Filing date: 2020-05-20
Publication date: 2021-11-30

Abstract

The application discloses a communication device and a filter thereof, wherein the filter comprises a shell; a common chamber disposed on the housing; the emission filtering branch is coupled with the common cavity and consists of ten filtering cavities which are sequentially coupled to form three capacitive cross coupling zeros; the bandwidth range of the emission filtering branch circuit is 925MHz-960 MHz; the receiving filter branch circuit is coupled with the common cavity and consists of eight filter cavities which are sequentially coupled to form three inductive cross coupling zeros; wherein, the bandwidth range of the receiving filter branch circuit is 880MHz-915 MHz. The transmitting filtering branch can realize filtering of 925MHz-960MHz bandwidth, and the receiving filtering branch can realize filtering of 880MHz-915MHz bandwidth; the transmitting filtering branch and the receiving filtering branch respectively form three capacitive coupling zeros and three inductive cross coupling zeros, so that the stop band rejection performance of the filter can be improved; the application realizes the combination between the transmitting filtering branch and the receiving filtering branch by setting the common cavity, and realizes the requirement of high intermodulation of the filter.

Description

Communication equipment and filter

Technical Field

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

Background

The cavity filter is a key device of a modern mobile communication system and is widely applied to wireless communication base stations and various communication terminals; the cavity filter is composed of a radio frequency connector, a cavity, a cover plate, a plurality of resonator units and a frequency tuning and coupling strength adjusting component, wherein the resonant frequencies of the plurality of resonator units are distributed in the passband range, and the cavity filter has a blocking function on signals outside the resonant frequencies, so that the function of selecting microwave transmission signals is realized; the cavity filter has the advantages of reliable structure, wide filtering frequency band, parasitic pass band far away from a channel, high Q value, stable electrical property, good heat dissipation performance and the like.

The inventor of the present application finds, in long-term research and development work, that the stop band rejection performance of the existing cavity filter is poor.

Disclosure of Invention

The application provides a communication device and a filter thereof, which are used for improving the stop band suppression performance of the filter.

In order to solve the above technical problem, the present application provides a filter, including: a housing; a common chamber disposed on the housing; the emission filtering branch is coupled with the common cavity and consists of ten filtering cavities which are sequentially coupled to form three capacitive cross coupling zeros; the bandwidth range of the emission filtering branch circuit is 925MHz-960 MHz; the receiving filter branch circuit is coupled with the common cavity and consists of eight filter cavities which are sequentially coupled to form three inductive cross coupling zeros; wherein, the bandwidth range of the receiving filter branch circuit is 880MHz-915 MHz.

The common cavity is coupled with the first filter cavity of the transmitting filter branch circuit and the first filter cavity of the receiving filter branch circuit; the common cavity and ten filter cavities of the transmitting filter branch circuit are divided into four rows arranged along the second direction; the fifth filtering cavity, the sixth filtering cavity and the seventh filtering cavity of the emission filtering branch are in a row and are sequentially arranged along the first direction; the common cavity and the first filtering cavities of the emission filtering branch are in a row and are sequentially arranged along a first direction; the second filtering cavity, the fourth filtering cavity and the eighth filtering cavity of the emission filtering branch are in a row and are sequentially arranged along a first direction; the third filtering cavity, the ninth filtering cavity and the tenth filtering cavity of the emission filtering branch are in a row and are sequentially arranged along the first direction; wherein the second direction is perpendicular to the first direction.

The second filter cavity of the emission filter branch is close to the midline of the shell in the second direction relative to the first filter cavity of the emission filter branch, and an included angle between a connecting line of the center of the first filter cavity of the emission filter branch and the center of the second filter cavity of the emission filter branch and a connecting line of the center of the first filter cavity of the emission filter branch and the center of the common cavity is an obtuse angle; the third filter cavity of the transmitting filter branch is far away from the middle branching line of the shell in the second direction relative to the second filter cavity of the transmitting filter branch, and an included angle between a connecting line of the center of the second filter cavity of the transmitting filter branch and the center of the third filter cavity of the transmitting filter branch and a connecting line of the center line is an acute angle; the fifth filter cavity of the transmitting filter branch is far away from the middle branching line of the shell in the second direction relative to the fourth filter cavity of the transmitting filter branch, and an included angle between a connecting line of the center of the fifth filter cavity of the transmitting filter branch and the center of the fourth filter cavity of the transmitting filter branch and a connecting line of the center line is an acute angle; the projection of the center of the third filter cavity of the emission filter branch in the first direction is superposed with the projection of the center of the fifth filter cavity of the emission filter branch in the first direction; the projection of the center of the ninth filtering cavity of the emission filtering branch in the first direction is superposed with the projection of the center of the sixth filtering cavity of the emission filtering branch in the first direction; the projection of the center of the tenth filter cavity of the emission filter branch in the first direction is coincident with the projection of the center of the seventh filter cavity of the emission filter branch in the first direction.

And capacitive cross coupling is respectively performed between the second filtering cavity and the fourth filtering cavity of the transmitting filtering branch, between the fourth filtering cavity and the sixth filtering cavity of the transmitting filtering branch, and between the eighth filtering cavity and the tenth filtering cavity of the transmitting filtering branch, so that three capacitive cross coupling zeros of the transmitting filtering branch are formed.

The eight filter cavities of the receiving filter branch circuit are divided into three rows arranged along the second direction; the second filtering cavity, the first filtering cavity and the fifth filtering cavity of the receiving filtering branch are in a row and are sequentially arranged along a first direction; the third filtering cavity, the fourth filtering cavity and the sixth filtering cavity of the receiving filtering branch are in a row and are sequentially arranged along the first direction; the seventh filtering cavity and the eighth filtering cavity of the receiving filtering branch are in a row and are sequentially arranged along the first direction; wherein the second direction is perpendicular to the first direction.

The projection of the center of the first filter cavity of the receiving filter branch in the first direction is superposed with the projection of the center of the common cavity in the first direction; the projection of the center of the seventh filter cavity of the receiving filter branch in the first direction is superposed with the projection of the center of the fifth filter cavity of the receiving filter branch in the first direction; the third filter cavity of the receiving filter branch is close to the middle branching line of the shell in the first direction relative to the second filter cavity of the receiving filter branch, and an included angle between a connecting line of the center of the second filter cavity of the receiving filter branch and the center of the third filter cavity of the receiving filter branch and the center line is an acute angle; the seventh filter cavity of the receiving filter branch is close to the middle branching line of the shell in the first direction relative to the sixth filter cavity of the receiving filter branch, and an included angle between a connecting line of the center of the seventh filter cavity of the receiving filter branch and the center of the sixth filter cavity of the receiving filter branch and the center line is an acute angle.

And the inductive cross coupling is respectively carried out between the first filtering cavity and the third filtering cavity of the receiving filtering branch, between the fourth filtering cavity and the sixth filtering cavity of the receiving filtering branch and between the sixth filtering cavity and the eighth filtering cavity of the receiving filtering branch so as to form three inductive cross coupling zeros of the receiving filtering branch.

The flying rods are arranged between the second filter cavity and the fourth filter cavity of the transmitting filter branch, between the fourth filter cavity and the sixth filter cavity of the transmitting filter branch and between the eighth filter cavity and the tenth filter cavity of the transmitting filter branch; metal coupling ribs are arranged between the common cavity and the first filter cavity of the transmitting filter branch circuit, between the common cavity and the first filter cavity of the receiving filter branch circuit, between the third filter cavity and the fourth filter cavity of the receiving filter branch circuit, between the sixth filter cavity and the seventh filter cavity of the receiving filter branch circuit and between the seventh filter cavity and the eighth filter cavity of the receiving filter branch circuit.

Wherein the filter further comprises: the resonance rod comprises a U-shaped side wall and a hollow inner cavity formed by the U-shaped side wall; the top end of the U-shaped side wall bends and extends in a direction away from the hollow inner cavity so as to form a disc-shaped structure at the top end of the U-shaped side wall, and the disc-shaped structure is parallel to the bottom of the U-shaped side wall; one end of the tuning rod is arranged in the hollow inner cavity; and the U-shaped side wall is fixed on the mounting column.

In order to solve the above technical problem, the present application provides a communication device, including an antenna and a radio frequency unit connected to the antenna; the radio frequency unit comprises a filter as described above for filtering the radio frequency signal.

The beneficial effect of this application is: compared with the prior art, the transmitting filtering branch can realize filtering with bandwidth of 925MHz-960MHz, and the receiving filtering branch can realize filtering with bandwidth of 880MHz-915 MHz; the transmitting filtering branch and the receiving filtering branch respectively form three capacitive coupling zeros and three inductive cross coupling zeros, so that the stop band rejection performance of the filter can be improved; the application realizes the combination between the transmitting filtering branch and the receiving filtering branch by setting the common cavity, and realizes the requirement of high intermodulation of the filter.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the description of the embodiments are briefly introduced 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 based on these drawings without creative efforts.

Fig. 1 is a schematic structural diagram of an embodiment of a transmit filter branch according to the present application;

FIG. 2 is a schematic diagram of a topology of a transmit filter branch of the present application;

FIG. 3 is a schematic structural view of the filter cavity, tuning rod, resonating rod, and mounting post assembly of FIG. 1;

FIG. 4 is a schematic structural diagram of an embodiment of a receiving filter branch according to the present application;

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

FIG. 6 is a schematic diagram of an equivalent circuit structure of the filter of the present application;

FIG. 7 is a schematic diagram of a simulated structure of a filter according to the present application;

fig. 8 is a schematic structural diagram of an embodiment of the communication device of the present application.

Detailed Description

In order to make those skilled in the art better understand the technical solution of the present application, the communication device and the filter provided in the present application are described in further detail below with reference to the accompanying drawings and the detailed description. It is to be understood that the embodiments described are only a few embodiments of the present application and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

The terms "first", "second", etc. in this application are used to distinguish between different objects and not to describe a particular order. Furthermore, the terms "include" and "have," as well as any variations thereof, are intended to cover non-exclusive inclusions. For example, a process, method, system, article, or apparatus that comprises a list of steps or elements is not limited to only those steps or elements listed, but may alternatively include other steps or elements not listed, or inherent to such process, method, article, or apparatus.

Referring to fig. 1 to 7, fig. 1 is a schematic structural diagram of an embodiment of a transmitting filter branch according to the present application; FIG. 2 is a schematic diagram of a topology of a transmit filter branch of the present application; FIG. 3 is a schematic structural view of the filter cavity, tuning rod, resonating rod, and mounting post assembly of FIG. 1; FIG. 4 is a schematic structural diagram of an embodiment of a receiving filter branch according to the present application; FIG. 5 is a schematic diagram of the topology of the receive filter branch of the present application; FIG. 6 is a schematic diagram of an equivalent circuit structure of the filter of the present application; fig. 7 is a schematic diagram of a simulation structure of the filter of the present application.

The filter 10 of the present embodiment includes: housing 11, common cavity a0, transmit filter branch 12, and receive filter branch 13.

A common cavity a0 is provided in the housing 11 and is coupled to the transmit filter branch 12 and the receive filter branch 13, respectively.

The emission filtering branch 12 is arranged on the housing 11 and consists of ten filtering cavities 121 coupled in sequence, 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, wherein the first filtering cavity a1 is coupled with the common cavity a 0. Wherein the transmit filter branch 12 further forms three capacitive cross-coupling zeros. The bandwidth range of the transmitting and filtering branch 12 is 925MHz-960 MHz.

The receiving filtering branch 13 is disposed on the housing 11, and is composed of eight filtering cavities 131 coupled in sequence, namely 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, and an eighth filtering cavity B8, wherein the first filtering cavity B1 is coupled with a common cavity a 0. Wherein the receiving filtering branch 13 further forms three inductive cross-coupling zeros. The bandwidth range of the receiving filter branch 13 is 880MHz-915 MHz.

Different from the prior art, the transmitting filtering branch 12 in this embodiment can implement filtering with bandwidth ranging from 925MHz to 960MHz, and the receiving filtering branch 13 can implement filtering with bandwidth ranging from 880MHz to 915 MHz; in this embodiment, the transmitting filtering branch 12 forms three capacitive coupling zeros and the receiving filtering branch 13 forms three inductive cross-coupling zeros, so that a stronger mutual suppression function between the transmitting filtering branch 12 and the receiving filtering branch 13 can be achieved, a strong suppression effect on the bandwidth of the filter 10 is achieved, and the stop band suppression performance of the filter 10 is improved.

As shown in fig. 1, the ten filter cavities 121 of the transmitting filter branch 12 and the common cavity a0 are divided into four columns arranged along the second direction ii. Wherein, first direction I and second direction II are mutually perpendicular. Alternatively, the first direction i may be a length direction of the housing 11, and the second direction ii may be a width direction of the housing 11.

The common cavity a0 and the first filter cavity a1 of the transmitting filter branch 12 are in a row and are sequentially arranged along a first direction i; the fifth filtering cavity A5, the sixth filtering cavity A6 and the seventh filtering cavity A7 of the emission filtering branch 12 are in a row and are sequentially arranged along the first direction I; the second filtering cavity A2, the fourth filtering cavity A4 and the eighth filtering cavity A8 of the emission filtering branch 12 are in a row and are sequentially arranged along the first direction I; the third filter cavity A3, the ninth filter cavity a9 and the tenth filter cavity a10 of the emission filter branch 12 are in a row and are sequentially arranged along the first direction i.

The second filter cavity a2 of the emission filter branch 12 is close to the midline of the housing 11 in the second direction ii relative to the first filter cavity a1 of the emission filter branch 12, and an included angle between a connecting line between the center of the first filter cavity a1 of the emission filter branch 12 and the center of the second filter cavity a2 of the emission filter branch 12 and a connecting line between the center of the first filter cavity a1 of the emission filter branch 12 and the center of the common cavity a0 is an obtuse angle; the third filter cavity A3 of the transmitting filter branch 12 is separated from the second filter cavity a2 of the transmitting filter branch 12 toward the middle branching line of the housing 11 in the second direction ii, and an included angle between a connecting line of the center of the second filter cavity a2 of the transmitting filter branch 12 and the center A3 of the third filter cavity of the transmitting filter branch 12 and a connecting line of the center line is an acute angle; the fifth filter cavity a5 of the transmitting filter branch 12 is separated from the fourth filter cavity a4 of the transmitting filter branch 12 toward the middle branch of the housing 11 in the second direction ii, and an included angle between a connecting line of the center of the fifth filter cavity a5 of the transmitting filter branch 12 and the center of the fourth filter cavity a4 of the transmitting filter branch 12 and a connecting line of the center line is an acute angle. Alternatively, the obtuse angle may be any angle greater than 90 ° and less than 180 °, such as 120 °. Alternatively, the acute angle may be any angle greater than 0 ° and less than 90 °, such as 30 °.

Wherein, the projection of the center of the third filter cavity A3 of the emission filter branch 12 in the first direction i coincides with the projection of the center of the fifth filter cavity a5 of the emission filter branch 12 in the first direction i; the projection of the center of the ninth filter cavity a9 of the emission filter branch 12 in the first direction i coincides with the projection of the center of the sixth filter cavity a6 of the emission filter branch 12 in the first direction i; the projection of the center of the tenth filter cavity a10 of the transmitting filter branch 12 onto the first direction i coincides with the projection of the center of the seventh filter cavity a7 of the transmitting filter branch 12 onto the first direction i.

Optionally, the ten filter cavities 121 of the transmit filter branch 12 are the same size and shape.

As can be seen from fig. 1, the ten filter cavities 121 and the common cavity a0 of the emission filter branch 12 are divided into four rows regularly arranged along the second direction ii, and the projections of the third filter cavity A3 and the fifth filter cavity a5, the ninth filter cavity a9 and the sixth filter cavity a6, and the projection of the tenth filter cavity a10 and the seventh filter cavity a7 are overlapped, so that the row cavities of the filter 10 are regularly compact, and the processing and the volume reduction are facilitated.

As shown in fig. 1 and 3, the ten filter cavities 121 of the transmitting filter branch 12 are each provided with a resonant rod 14 and a tuning rod 15. The resonant rod 14 includes a U-shaped sidewall 141 and a hollow cavity 142 formed by the U-shaped sidewall 141, and one end of the tuning rod 15 is disposed in the hollow cavity 142. The transmission filter branch 12 of the present embodiment can adjust the resonant frequency of the filter cavity 121 by adjusting the depth of the tuning rod 15 in the hollow inner cavity 142.

Optionally, the resonant rod 14, the hollow interior 142 and the tuning rod 15 are coaxially arranged.

Alternatively, as shown in fig. 3, the top end of the U-shaped sidewall 141 is bent and extended away from the hollow cavity 142 to form a disc structure 143 at the top end of the U-shaped sidewall 141, and the disc structure 143 is disposed parallel to the bottom of the U-shaped sidewall 141. The disc-like structure 143 at the top end of the U-shaped sidewall 141 can increase the signal coupling amount of the resonant bar 14.

Alternatively, the ten filter cavities 121 of the transmitting filter branch 12 may be metal filter cavities, and the resonant rod 14 may be a metal resonant rod. Wherein the metal material may be iron. The resonant rod 14 made of the ferrous material is used in the embodiment, so that the production cost can be effectively reduced.

Optionally, the material of the resonant rod 14 of the present embodiment may be a thread 1215MS, an M8 or an M4 screw.

As shown in fig. 3, the housing 11 is further provided with a mounting post 16, and the U-shaped sidewall 141 is fixed to the mounting post 16 and fixed to the housing 11 by the mounting post 16.

Further, a mounting hole (not shown) may be provided on the bottom of the U-shaped sidewall 141, one end of the mounting post 16 is fixed to the housing 11, and the other end of the mounting post 16 is mounted in the mounting hole to fix the resonant rod 14 to the mounting post 16. Alternatively, the mounting hole may be a through hole, a blind hole, a threaded hole, or the like, the mounting post 16 may be a stud, and the mounting post 16 is configured with the mounting hole.

Further, the filter 10 further includes a cover plate (not shown) covering the ten filter cavities 121 of the transmitting filter branch 12, and the other end of the tuning rod 15 is disposed on the cover plate. Alternatively, the tuning rod 15 may be a metal screw, and a screw hole is provided on the cover plate, so that the tuning rod 15 is inserted into the cover plate.

The 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. 2, the flying rods 17 are respectively disposed between the second filtering cavity a2 and the fourth filtering cavity a4, between the fourth filtering cavity a4 and the sixth filtering cavity A6, and between the eighth filtering cavity A8 and the tenth filtering cavity a10 of the emission filtering branch 12 of the present embodiment, and the capacitive cross coupling is realized by the flying rods 17, which is equivalent to that a first capacitor C1, a second capacitor C2, and a third capacitor C3 are respectively disposed between the second filtering cavity a2 and the fourth filtering cavity a4, between the fourth filtering cavity a4 and the sixth filtering cavity A6, and between the eighth filtering cavity A8 and the tenth filtering cavity a 10. Capacitive cross coupling is adopted between the second filter cavity a2 and the fourth filter cavity a4, between the fourth filter cavity a4 and the sixth filter cavity a6, and between the eighth filter cavity A8 and the tenth filter cavity a10, so that the emission filter branch 12 generates three transmission zeros, namely three capacitive cross coupling zeros, at the lower end of the passband.

Ten filter cavities 121 of the transmitting filter branch 12 are arranged adjacently in sequence along a main coupling path, a first window (not shown) is arranged between any group of adjacent filter cavities 121, and electromagnetic energy is transmitted between two adjacent filter cavities 121 on the main coupling path through the first window. For example, first windows are respectively 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, and between the ninth filter cavity a9 and the tenth filter cavity a 10.

Further, a first window is formed between the common cavity a0 and the first filter cavity a1 of the emission filter branch 12, and a metal coupling rib 18 is arranged, so that the coupling strength between the common cavity a0 and the first filter cavity a1 of the emission filter branch 12 is improved.

Further, the transmitting filter branch circuit 12 of the present embodiment further includes: an input port (not shown) connected to the common cavity a0 and an output port (not shown) connected to the tenth filter cavity a10 of the transmit filter branch 12. The input port and the output port are both taps.

As shown in fig. 4, the eight filter cavities 131 of the receiving filter branch 13 are divided into three columns arranged in the second direction ii. Wherein, first direction I and second direction II are mutually perpendicular. Alternatively, the first direction i may be a length direction of the housing 11, and the second direction ii may be a width direction of the housing 11.

The second filtering cavity B2, the first filtering cavity B1 and the fifth filtering cavity B5 of the receiving filtering branch circuit 13 are in a row and are sequentially arranged along the first direction I; the third filtering cavity B3, the fourth filtering cavity B4 and the sixth filtering cavity B6 of the receiving filtering branch 13 are in a row and are sequentially arranged along the first direction i; the seventh filter cavity B7 and the eighth filter cavity B8 of the receiving filter branch 13 are aligned in a row and are arranged in sequence along the first direction i.

The third filter cavity B3 of the receiving filter branch 13 is close to the centerline of the housing 11 in the first direction i relative to the second filter cavity B2 of the receiving filter branch 13, and an included angle between a connecting line of the center of the second filter cavity B2 of the receiving filter branch 13 and the center of the third filter cavity B3 of the receiving filter branch 13 and the centerline is an acute angle; the seventh filter cavity B7 of the receiving filter branch 13 is close to the centerline of the housing 11 in the first direction i relative to the sixth filter cavity B6 of the receiving filter branch 13, and an included angle between a connecting line of the center of the seventh filter cavity B7 of the receiving filter branch 13 and the center of the sixth filter cavity B6 of the receiving filter branch 13 and the centerline is an acute angle. Alternatively, the acute angle may be any angle greater than 0 ° and less than 90 °, such as 30 °.

Wherein the projection of the center of the first filter cavity B1 of the receiving filter branch 13 in the first direction i coincides with the projection of the center of the common cavity a0 in the first direction i; the projection of the center of the seventh filter chamber B7 of the receiving filter branch 13 in the first direction i coincides with the projection of the center of the fifth filter chamber B5 of the receiving filter branch 13 in the first direction i.

Optionally, the eight filter cavities 131 of the receiving filter branch 13 are of the same size and shape.

As can be seen from fig. 4, the eight filter cavities 131 of the receiving filter branch 13 are divided into three rows regularly arranged along the second direction ii, and the projections of the first filter cavity B1 and the common cavity a0, and the projections of the seventh filter cavity B7 and the fifth filter cavity B5 are overlapped, so that the rows of cavities of the filter 10 are regularly compact, and the processing and the volume reduction are convenient.

Further, the eight filter cavities 131 receiving the filter branches 13 are all provided with a resonance rod, a tuning rod and a mounting post, and the structures and the arrangements of the resonance rod, the tuning rod and the mounting post are the same as those shown in fig. 3, and are not described herein again. Alternatively, the resonant rod is a metallic resonant rod and the metallic material may be copper. The resonant rod made of the copper material is used in the embodiment, so that the production cost can be effectively reduced.

As can be seen from fig. 1 and 3, the size of the filter cavity 131 of the receiving filter branch 13 is smaller than the size of the filter cavity 121 of the transmitting filter branch 12.

As shown in fig. 4 and fig. 5, in this embodiment, second windows (not shown) are respectively disposed between the first filter cavity B1 and the third filter cavity B3 of the receiving filter branch 13, between the fourth filter cavity B4 and the sixth filter cavity B6 of the receiving filter branch 13, and between the sixth filter cavity B6 and the eighth filter cavity B8 of the receiving filter branch 13, and the inductive cross coupling is realized through the second windows, which is equivalent to that a first inductor L1, a second inductor L2, and a third inductor L3 are respectively disposed between the first filter cavity B1 and the third filter cavity B3, between the fourth filter cavity B4 and the sixth filter cavity B6, and between the sixth filter cavity B6 and the eighth filter cavity B8. Inductive cross coupling is respectively adopted between the first filter cavity B1 and the third filter cavity B3, between the fourth filter cavity B4 and the sixth filter cavity B6, and between the sixth filter cavity B6 and the eighth filter cavity B8, so that the receiving filter branch circuit 13 generates three transmission zeros, namely three inductive cross coupling zeros, at the high end of the pass band.

Eight filter cavities 131 of this embodiment receiving filter branch 13 are arranged adjacently along the main coupling path in proper order, and all are equipped with first window (not marked in the figure) between the filter cavity 131 that arbitrary a set of adjacent setting, carry out electromagnetic energy transmission through first window on the main coupling path between two adjacent filter cavities 131. For example, first windows are respectively disposed between the first filter cavity B1 and the second filter cavity B2, between the second filter cavity B2 and the third filter cavity B3, between the third filter cavity B3 and the fourth filter cavity B4, between the fourth filter cavity B4 and the fifth filter cavity B5, between the fifth filter cavity B5 and the sixth filter cavity B6, between the sixth filter cavity B6 and the seventh filter cavity B7, and between the seventh filter cavity B7 and the eighth filter cavity B8.

Further, a first window is formed between the common cavity a0 and the first filter cavity B1 of the receiving filter branch 13, and a metal coupling rib 18 is arranged, so that the coupling strength between the common cavity a0 and the first filter cavity a1 of the transmitting filter branch 12 is improved.

Further, metal coupling ribs 18 are arranged between the third filtering cavity B3 and the fourth filtering cavity B4, between the sixth filtering cavity B6 and the seventh filtering cavity B7, and between the seventh filtering cavity B7 and the eighth filtering cavity B8 of the receiving filtering branch 13, so that the coupling strength between the adjacent filtering cavities 131 is improved.

Further, the receiving filter branch circuit 13 of the present embodiment includes: an input port (not shown) connected to the common chamber a0 and an output port (not shown) connected to the eighth filter chamber B8 of the receiving filter branch 13. The input port and the output port are both taps.

As shown in fig. 6, in the equivalent circuit of the filter 10 of this embodiment, an impedance Z1 is provided at an input port, an impedance Z2 is provided at an output port of the transmitting filtering branch 12, and an impedance Z3 is provided at an output port of the receiving filtering branch 13.

In order to ensure that electromagnetic signals are transmitted between the common chamber a0 and the first filter chamber a1 of the transmitting filter branch 12, between the ten filter chambers 121 of the transmitting filter branch 12, between the common chamber a0 and the first filter chamber B1 of the receiving filter branch 13, and between the eight filter chambers 131 of the receiving filter branch 13, it is necessary to transmit electromagnetic signals between the input port and the common chamber a0, between the common chamber a0 and the first filter chamber a1 of the transmitting filter branch 12, between the common chamber a0 and the first filter chamber B1 of the receiving filter branch 13, between adjacent filter chambers 121 of the transmitting filter branch 12, between adjacent filter chambers 131 of the receiving filter branch 13, between the non-cascaded filter chambers 121 of the transmitting filter branch 12 forming a cross coupling, between the non-cascaded filter chambers 131 of the receiving filter branch 13 forming a cross coupling, between the tenth filter chamber a10 of the transmitting filter branch 12 and the output port of the transmitting filter branch 12, and between the eighth filter chambers 8 of the receiving filter branch 13 and the output port of the receiving filter branch 13 Impedance regulators ZV are respectively arranged between the output ports to realize impedance matching.

The simulation result of the filter 10 of this embodiment is shown in fig. 7, and it can be known from fig. 7 that the bandwidth of the transmitting and filtering branch 12 of this embodiment is about 925MHz-960 MHz; there are three low-end coupling zeros a, b, c, as shown by the band curve S2. The rejection at point a exceeds 140dB, the rejection at point b exceeds 130dB, and the rejection at point c exceeds 120dB, i.e. the rejection of the low end outside the passband of the transmit filter branch 12 is greater than 120dB, and the in-band loss of the transmit filter branch 12 is less than 2 dB; the bandwidth of the receiving filter branch 13 in this embodiment is about 880MHz-915 MHz; as shown in the band curve S1, there are three high-end coupling zeros d, e, and f. The rejection at the point d exceeds 100dB, the rejection at the point e exceeds 120dB, and the rejection at the point f exceeds 110dB, that is, the rejection of the low end outside the passband of the receiving filtering branch 13 is greater than 100dB, and the in-band loss of the receiving filtering branch 13 is less than 1.5dB, so that a stronger mutual rejection function between the transmitting filtering branch 12 and the receiving filtering branch 13 is realized, and the filter 10 has the characteristics of strong anti-interference capability and small in-band loss.

The filter 10 in the embodiment of the application has the advantages of low loss, capability of ensuring low energy consumption of the communication module, simple design scheme, low cost and good structure and electrical property stability. The filter 10 realizes the combination between the transmitting filtering branch 12 and the receiving filtering branch 13 by arranging the common cavity a0, and the requirement of high intermodulation of the filter 10 is realized.

Referring to fig. 8, fig. 8 is a schematic structural diagram of an embodiment of a communication device according to the present application. The communication device 20 of the present embodiment includes an antenna 22 and a radio frequency unit 21 connected to the antenna 22, the radio frequency unit 21 includes a filter 10 as shown in the above-mentioned embodiment, and the filter 10 is used for filtering radio frequency signals. In other embodiments, the rf Unit 21 may be integrated with the Antenna 22 to form an Active Antenna Unit (AAU).

Optionally, the communication device 20 is one of a multiplexer, a filter, a splitter, a combiner, and a tower top amplifier.

The above embodiments are merely examples, and not intended to limit the scope of the present application, and all modifications, equivalents, and flow charts using the contents of the specification and drawings of the present application, or those directly or indirectly applied to other related arts, are included in the scope of the present application.

Claims

1. A filter, characterized in that the filter comprises:

a housing;

a common chamber disposed on the housing;

the emission filtering branch is coupled with the common cavity, consists of ten filtering cavities which are sequentially coupled and forms three capacitive cross coupling zeros; the bandwidth range of the transmitting and filtering branch circuit is 925MHz-960 MHz;

the receiving filter branch circuit is coupled with the common cavity and consists of eight filter cavities which are sequentially coupled to form three inductive cross coupling zeros; the bandwidth range of the receiving filtering branch circuit is 880MHz-915 MHz.

2. The filter of claim 1,

the common cavity is coupled with the first filter cavity of the transmitting filter branch circuit and the first filter cavity of the receiving filter branch circuit;

the common cavity and ten filter cavities of the transmitting filter branch circuit are divided into four rows arranged along a second direction;

the fifth filtering cavity, the sixth filtering cavity and the seventh filtering cavity of the emission filtering branch are in a row and are sequentially arranged along a first direction;

the common cavity and the first filtering cavities of the emission filtering branch are in a row and are sequentially arranged along the first direction;

the second filtering cavity, the fourth filtering cavity and the eighth filtering cavity of the emission filtering branch are in a row and are sequentially arranged along the first direction;

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

wherein the second direction is perpendicular to the first direction.

3. The filter of claim 2,

the second filter cavity of the transmitting filter branch is close to the middle branching line of the shell in the second direction relative to the first filter cavity of the transmitting filter branch, and an included angle between a connecting line of the center of the first filter cavity of the transmitting filter branch and the center of the second filter cavity of the transmitting filter branch and a connecting line of the center of the first filter cavity of the transmitting filter branch and the center of the common cavity is an obtuse angle;

the third filter cavity of the transmitting filter branch is far away from the middle branching line of the shell in the second direction relative to the second filter cavity of the transmitting filter branch, and an included angle between a connecting line of the center of the second filter cavity of the transmitting filter branch and the center of the third filter cavity of the transmitting filter branch and a connecting line of the center line is an acute angle;

the fifth filter cavity of the transmitting filter branch is far away from the middle branching line of the shell in the second direction relative to the fourth filter cavity of the transmitting filter branch, and an included angle between a connecting line of the center of the fifth filter cavity of the transmitting filter branch and the center of the fourth filter cavity of the transmitting filter branch and a connecting line of the center line is an acute angle;

the projection of the center of the third filter cavity of the emission filter branch in the first direction is coincident with the projection of the center of the fifth filter cavity of the emission filter branch in the first direction;

the projection of the center of the ninth filter cavity of the emission filter branch in the first direction is coincident with the projection of the center of the sixth filter cavity of the emission filter branch in the first direction;

and the projection of the center of the tenth filter cavity of the emission filter branch in the first direction is coincident with the projection of the center of the seventh filter cavity of the emission filter branch in the first direction.

4. The filter according to claim 3, wherein capacitive cross coupling is performed between the second filter cavity and the fourth filter cavity of the transmitting filter branch, between the fourth filter cavity and the sixth filter cavity of the transmitting filter branch, and between the eighth filter cavity and the tenth filter cavity of the transmitting filter branch, respectively, to form three capacitive cross coupling zeros of the transmitting filter branch.

5. The filter of claim 1,

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

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

the third filtering cavity, the fourth filtering cavity and the sixth filtering cavity of the receiving filtering branch are in a row and are sequentially arranged along the first direction;

the seventh filtering cavity and the eighth filtering cavity of the receiving filtering branch are in a row and are sequentially arranged along the first direction;

wherein the second direction is perpendicular to the first direction.

6. The filter of claim 5,

the projection of the center of the first filter cavity of the receiving filter branch in the first direction is coincident with the projection of the center of the common cavity in the first direction;

the projection of the center of the seventh filter cavity of the receiving filter branch in the first direction is coincident with the projection of the center of the fifth filter cavity of the receiving filter branch in the first direction;

the third filter cavity of the receiving filter branch is close to the middle branching line of the shell in the first direction relative to the second filter cavity of the receiving filter branch, and an included angle between a connecting line of the center of the second filter cavity of the receiving filter branch and the center of the third filter cavity of the receiving filter branch and the central line is an acute angle;

the seventh filter cavity of the receiving filter branch is close to the middle branching line of the shell in the first direction relative to the sixth filter cavity of the receiving filter branch, and an included angle between a connecting line of the center of the seventh filter cavity of the receiving filter branch and the center of the sixth filter cavity of the receiving filter branch and the central line is an acute angle.

7. The filter of claim 6,

and the inductive cross coupling is respectively performed between the first filtering cavity and the third filtering cavity of the receiving filtering branch, between the fourth filtering cavity and the sixth filtering cavity of the receiving filtering branch, and between the sixth filtering cavity and the eighth filtering cavity of the receiving filtering branch, so as to form three inductive cross coupling zeros of the receiving filtering branch.

8. The filter of claim 1,

flying rods are arranged between the second filter cavity and the fourth filter cavity of the transmitting filter branch, between the fourth filter cavity and the sixth filter cavity of the transmitting filter branch and between the eighth filter cavity and the tenth filter cavity of the transmitting filter branch;

metal coupling ribs are arranged between the common cavity and the first filter cavity of the transmitting filter branch circuit, between the common cavity and the first filter cavity of the receiving filter branch circuit, between the third filter cavity and the fourth filter cavity of the receiving filter branch circuit, between the sixth filter cavity and the seventh filter cavity of the receiving filter branch circuit and between the seventh filter cavity and the eighth filter cavity of the receiving filter branch circuit.

9. The filter of claim 1, wherein the filter further comprises:

the resonance rod comprises a U-shaped side wall and a hollow inner cavity formed by the U-shaped side wall; the top end of the U-shaped side wall is bent and extended in a direction away from the hollow inner cavity so as to form a disc-shaped structure at the top end of the U-shaped side wall, and the disc-shaped structure is arranged in parallel with the bottom of the U-shaped side wall;

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

and the U-shaped side wall is fixed on the mounting column.

10. A communication device, characterized in that the communication device comprises an antenna and a radio frequency unit connected with the antenna; the radio frequency unit comprising a filter according to any of claims 1-9 for filtering a radio frequency signal.