CN212571290U

CN212571290U - Filter and communication equipment

Info

Publication number: CN212571290U
Application number: CN202020681874.9U
Authority: CN
Inventors: 符其略; 李华
Original assignee: Shenzhen Tatfook Technology Co Ltd
Current assignee: Anhui Tatfook Technology Co Ltd
Priority date: 2020-04-28
Filing date: 2020-04-28
Publication date: 2021-02-19
Anticipated expiration: 2030-04-28

Abstract

The application discloses a filter and communication equipment. The filter includes: the first emission filtering branch consists of eleven emission filtering cavities which are coupled in sequence to form five capacitive cross-coupling zeros; the second emission filtering branch consists of eight emission filtering cavities which are sequentially coupled to form three capacitive cross coupling zeros; the first receiving filter branch consists of nine receiving filter cavities which are coupled in sequence to form three inductive cross coupling zeros; the second receiving filter branch consists of seven receiving filter cavities which are coupled in sequence to form three capacitive cross coupling zeros. In this way, the stop-band rejection performance of the filter can be improved.

Description

Filter and communication equipment

Technical Field

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

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 for 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 arrangement of a plurality of filter cavities in the existing cavity filter is complex and irregular, the size of the filter is increased, and the stop band inhibition performance of the cavity filter is poor.

SUMMERY OF THE UTILITY MODEL

The application provides a filter and communication equipment, so as to improve stop band suppression performance of the filter.

In order to solve the technical problem, the application adopts a technical scheme that: providing a filter comprising a housing;

the first emission filtering branch is arranged on the shell and consists of eleven emission filtering cavities which are sequentially coupled; capacitive cross coupling is respectively formed between a second emission filtering cavity and a fourth emission filtering cavity, between a second emission filtering cavity and a fifth emission filtering cavity, between a fifth emission filtering cavity and a seventh emission filtering cavity, between the seventh emission filtering cavity and a tenth emission filtering cavity, and between an eighth emission filtering cavity and a tenth emission filtering cavity of the first emission filtering branch;

the second emission filtering branch is arranged on the shell and consists of eight emission filtering cavities which are sequentially coupled; capacitive cross coupling is respectively formed between a third emission filter cavity and a fifth emission filter cavity, between the fifth emission filter cavity and an eighth emission filter cavity, and between a sixth emission filter cavity and the eighth emission filter cavity of the second emission filter branch circuit;

the first receiving and filtering branch is arranged on the shell and consists of nine receiving and filtering cavities which are coupled in sequence; the second receiving filter cavity and the fourth receiving filter cavity, the second receiving filter cavity and the fifth receiving filter cavity, and the sixth receiving filter cavity and the eighth receiving filter cavity of the first receiving filter branch are in inductive cross coupling respectively;

the second receiving filter branch is arranged on the shell and consists of seven receiving filter cavities which are sequentially coupled; and the first receiving filter cavity and the third receiving filter cavity, the fourth receiving filter cavity and the sixth receiving filter cavity, and the fourth receiving filter cavity and the seventh receiving filter cavity of the second receiving filter branch are respectively in capacitive cross coupling.

In order to solve the above technical problem, the present application adopts another technical solution: there is provided a communication device comprising an antenna and a radio frequency unit connected to the antenna, the radio frequency unit comprising the above-mentioned filter for filtering a radio frequency signal.

The beneficial effect of this application is: different from the prior art, in the embodiment of the present application, capacitive cross coupling is respectively performed between the second emission filter cavity and the fourth emission filter cavity, between the second emission filter cavity and the fifth emission filter cavity, between the fifth emission filter cavity and the seventh emission filter cavity, between the seventh emission filter cavity and the tenth emission filter cavity, and between the eighth emission filter cavity and the tenth emission filter cavity of the first emission filter branch, so that high-end rejection of the bandwidth of the first emission filter branch can be well controlled to obtain better high-end rejection of the bandwidth, and low-end rejection of the bandwidth of the first emission filter branch can be well controlled to obtain better low-end rejection of the bandwidth; capacitive cross coupling is respectively formed between a third emission filter cavity and a fifth emission filter cavity, between a fifth emission filter cavity and an eighth emission filter cavity, and between a sixth emission filter cavity and an eighth emission filter cavity of the second emission filter branch, so that high-end suppression of the bandwidth of the second emission filter branch can be well controlled to obtain better high-end suppression of the bandwidth, and low-end suppression of the bandwidth of the second emission filter branch can be well controlled to obtain better low-end suppression of the bandwidth; inductive cross coupling is respectively carried out between a second receiving filter cavity and a fourth receiving filter cavity, between a second receiving filter cavity and a fifth receiving filter cavity and between a sixth receiving filter cavity and an eighth receiving filter cavity of the first receiving filter branch, so that the high-end suppression of the bandwidth of the first receiving filter branch can be well controlled, better high-end suppression of the bandwidth can be obtained, the low-end suppression of the bandwidth of the first receiving filter branch can be well controlled, and better low-end suppression of the bandwidth can be obtained; the first receiving filter cavity and the third receiving filter cavity of the second receiving filter branch circuit, the fourth receiving filter cavity and the sixth receiving filter cavity, the fourth receiving filter cavity and the seventh receiving filter cavity are in capacitive cross coupling, the high-end suppression of the bandwidth of the second receiving filter branch circuit can be well controlled, so that the good high-end suppression of the bandwidth can be obtained, the low-end suppression of the bandwidth of the second receiving filter branch circuit can be well controlled, the good low-end suppression of the bandwidth can be obtained, and therefore the stop band suppression performance of the filter can be improved.

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 structural diagram of a first transmit filter branch of a filter according to the present application;

FIG. 2 is a schematic diagram of a topology of a first transmit filter branch of the embodiment of FIG. 1;

FIG. 3 is a schematic structural diagram of a first tuning rod, a first resonant rod and a first mounting post assembly of the launch filter cavity of the embodiment of FIG. 1;

fig. 4 is a schematic structural diagram of a combined structure of a first flying bar and a first supporting clamping seat in the first emission filtering branch of the embodiment of fig. 1;

fig. 5 is a schematic diagram of an equivalent circuit structure of a first transmitting filter branch circuit in the embodiment of fig. 1;

FIG. 6 is a diagram illustrating a simulation structure of a filter according to an embodiment of the present application;

FIG. 7 is a schematic diagram of a second transmit filter branch of the filter of the present application;

FIG. 8 is a schematic diagram of the topology of the second transmit filter branch of the embodiment of FIG. 7;

fig. 9 is a schematic diagram of an equivalent circuit structure of a second transmitting filter branch in the embodiment of fig. 7;

fig. 10 is a schematic diagram of a first receiving filtering branch of the filter of the present application;

FIG. 11 is a schematic diagram of the topology of the first receiving filter branch of the embodiment of FIG. 10;

FIG. 12 is a schematic diagram of an equivalent circuit structure of the first receiving filter branch of the embodiment in FIG. 10;

fig. 13 is a schematic diagram of a second receive filter branch of the filter of the present application;

FIG. 14 is a schematic diagram of the topology of the second receive filter branch of the embodiment of FIG. 13;

FIG. 15 is a schematic diagram of an equivalent circuit structure of the second receiving filter branch of the embodiment in FIG. 13;

fig. 16 is a schematic diagram of an equivalent circuit structure of a filter formed by combining a first transmitting filter branch, a second transmitting filter branch, a first receiving filter branch and a second receiving filter branch;

fig. 17 is a schematic structural diagram of an embodiment of the communication device of the present application.

Detailed Description

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all of the 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" and "second" in this application are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. In the description of the present application, "plurality" means at least two, e.g., two, three, etc., unless explicitly specifically limited otherwise. 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.

First, a filter is proposed, please refer to fig. 1 and fig. 2, in which fig. 1 is a schematic structural diagram of a first transmitting and filtering branch of the filter of the present application, and fig. 2 is a schematic topological structural diagram of the first transmitting and filtering branch in the embodiment of fig. 1. The filter 10 of the present embodiment includes a housing 11 and a first transmitting filter branch 12. And the first emission filtering branch 12 is arranged on the shell 11 and consists of eleven emission filtering cavities which are coupled in sequence.

Specifically, the eleven emission filter cavities of the first emission filter branch 12 include a first emission filter cavity a1, a second emission filter cavity a2, a third emission filter cavity A3, a fourth emission filter cavity a4, a fifth emission filter cavity a5, a sixth emission filter cavity a6, a seventh emission filter cavity a7, an eighth emission filter cavity A8, a ninth emission filter cavity a9, a tenth emission filter cavity a10 and an eleventh emission filter cavity a 11; capacitive cross coupling is respectively formed between the second emission filter cavity A2 and the fourth emission filter cavity A4, between the second emission filter cavity A2 and the fifth emission filter cavity A5, between the fifth emission filter cavity A5 and the A7 of the seventh emission filter cavity, between the seventh emission filter cavity A7 and the tenth emission filter cavity A10, and between the eighth emission filter cavity A8 and the tenth emission filter cavity A10; the bandwidth of the first transmitting and filtering branch circuit 12 is 1805MHz-1880 MHz.

It can be seen that, capacitive cross coupling is respectively performed between the second emission filter cavity a2 and the fourth emission filter cavity a4, between the second emission filter cavity a2 and the fifth emission filter cavity a5, between the fifth emission filter cavity a5 and the a7 of the seventh emission filter cavity, between the seventh emission filter cavity a7 and the tenth emission filter cavity a10, and between the eighth emission filter cavity A8 and the tenth emission filter cavity a10 of the first emission filter branch 12, so that the high-end rejection of the bandwidth of the first emission filter branch can be well controlled, so as to obtain better high-end rejection of the bandwidth, and the low-end rejection of the bandwidth of the first emission filter branch can be well controlled, so as to obtain better low-end rejection of the bandwidth, thereby improving the stop-band rejection performance of the filter 10; in addition, the bandwidth of the first transmitting and filtering branch 12 ranges from 1805MHz to 1880MHz, and the bandwidth of the first transmitting and filtering branch 12 can be accurately controlled.

Optionally, as shown in fig. 1, the eleven emission filter cavities of the first emission filter branch 12 are divided into two rows arranged along a second direction y, and the second direction y is perpendicular to the first direction x; the first emission filter cavity a1, the second emission filter cavity a2, the fifth emission filter cavity a5, the seventh emission filter cavity a7, the tenth emission filter cavity a10 and the eleventh emission filter cavity a11 of the first emission filter branch 12 are in a row and are sequentially arranged along the first direction x; the third emission filter cavity A3, the fourth emission filter cavity a4, the sixth emission filter cavity a6, the eighth emission filter cavity A8 and the ninth emission filter cavity a9 of the first emission filter branch 12 are in a row and are sequentially arranged along the first direction x.

It can be seen that the eleven emission filter cavities are divided into two rows sequentially arranged along the second direction y, and the eleven emission filter cavities are regularly arranged, so as to reduce the volume of the first emission filter branch 12, and further reduce the volume of the filter 10.

Alternatively, as shown in fig. 1, eleven transmit filter cavities of the first transmit filter branch 12 are sequentially window-coupled, namely, the first emission filter cavity a1 is coupled with the second emission filter cavity a2 through a window, the second emission filter cavity a2 is coupled with the third emission filter cavity A3 through a window, the third emission filter cavity A3 is coupled with the fourth emission filter cavity a4 through a window, the fourth emission filter cavity a4 is coupled with the fifth emission filter cavity A5 through a window, the fifth emission filter cavity A5 is coupled with the sixth emission filter cavity A6 through a window, the sixth emission filter cavity A6 is coupled with the seventh emission filter cavity a7 through a window, the seventh emission filter cavity a7 is coupled with the eighth emission filter cavity A8 through a window, the eighth emission filter cavity A8 is coupled with the ninth emission filter cavity a9 through a window, the ninth emission filter cavity a9 is coupled with the tenth emission filter cavity a10 through a window, and the tenth emission filter cavity a10 a11 through a window.

Therefore, the two adjacent filter cavities on the coupling path of the first transmitting filter branch 12 are coupled by pure windows, so that the cost of the filter 10 can be reduced.

Referring to fig. 3, fig. 3 is a schematic structural diagram of a combination structure of a first tuning rod, a first resonant rod and a first mounting post of the transmission filter cavity in fig. 1. As shown in fig. 1 and 3, each of the emission filter cavities on the first emission filter branch 12 is provided with a first mounting post 40, a first resonance rod 20 and a first tuning rod 30. Wherein, the first resonant rod 20 comprises a first U-shaped sidewall 210 and a first hollow inner cavity 220 formed by the first U-shaped sidewall 210; one end of the first tuning rod 30 is disposed within the first hollow interior 220 and the resonant frequency of the first resonant cavity can be adjusted by adjusting the depth of the first tuning rod 30 within the first hollow interior 220. The two ends of the first U-shaped sidewall 210 are bent and extended in a direction away from the first hollow cavity 220, so as to form a first disc-shaped structure 230 at the two ends of the first U-shaped sidewall 210, and the first disc-shaped structure 230 is parallel to the bottom of the first U-shaped sidewall 210. The first U-shaped sidewall 210 is fixed to the first mounting post 40, as shown in fig. 3, the first U-shaped sidewall 210 is fixed to the first mounting post 40, and the first resonant rod 20 is fixed to the housing 11 through the first mounting post 40. The first resonant rod 20, the first hollow cavity 220, and the first tuning rod 30 of this embodiment are coaxially disposed.

Further, a mounting hole (not shown) may be provided on the bottom of the first U-shaped sidewall 210, one end of the first mounting post 40 is fixed on the housing 11, and the other end of the first mounting post 40 is mounted in the mounting hole, so as to fix the first resonant rod 20 on the first mounting post 40; the mounting holes may be through holes, the mounting holes may be threaded holes, and the first mounting post 40 is a stud. In other embodiments, the mounting hole may also be a blind hole.

Alternatively, the transmitting filter cavity of the present embodiment may be a metal filter cavity, and the first resonant rod 20 may be a metal resonant rod.

The material of the first resonant rod 20 of the present embodiment may be the cut 1215 MS. Of course, in other embodiments, the first resonant rod 20 may be an M8 or M4 screw rod, and may be made of copper, 45 steel, or silver.

The eight emission filter cavities of the first emission filter branch 12 have the same size, so that the production is convenient, and the cost is saved. The radii of the eight emission filter cavities may be less than 23mm, e.g., 23mm, 22mm, 21mm, 20mm, 19mm, 18mm, etc.

It can be seen that the first resonant rod 20 can be fixed to the housing 11 by the first mounting post 40, and the resonant frequency of the first resonant cavity can be adjusted by adjusting the depth of the first tuning rod 30 within the first hollow interior 220.

Referring to fig. 4, fig. 4 is a schematic structural diagram of a combined structure of a first flying bar and a first supporting clamping seat in a first emission filtering branch circuit of the embodiment of fig. 1. First flying rods 60 are respectively arranged between the second emission filter cavity A2 and the fourth emission filter cavity A4, between the second emission filter cavity A2 and the fifth emission filter cavity A5, between the fifth emission filter cavity A5 and A7 of the seventh emission filter cavity, between the seventh emission filter cavity A7 and the tenth emission filter cavity A10, and between the eighth emission filter cavity A8 and the tenth emission filter cavity A10 of the first emission filter branch 12, so that the emission filters are capacitively coupled between the second emission filter cavity A2 and the fourth emission filter cavity A4, between the second emission filter cavity A2 and the fifth emission filter cavity A5, between the fifth emission filter cavity A5 and A7 of the seventh emission filter cavity, between the seventh emission filter cavity A7 and the tenth emission filter cavity A10, and between the eighth emission filter cavity A8A 10. The arrangement of the first fly rod 60 can simplify the structure, facilitate processing and manufacturing, reduce production cost and improve the realizability of the scheme.

Specifically, the first flying bar 60 includes a first coupling portion 610, a second coupling portion 620 and a first connecting portion 630, two ends of the first connecting portion 630 are respectively connected with the first coupling portion 610 and the second coupling portion 620, and the first coupling portion 610 and the second coupling portion 620 are located on the same side of the first connecting portion 630. The first coupling portion 610, the first connecting portion 630, and the second coupling portion 620 are sequentially connected to form a first flying bar 60; the first coupling part 610 is coupled with the first resonance rod 20 in the second emission filter cavity a2 to form a coupling capacitance between the first coupling part 610 and the first resonance rod 20, and the second coupling part 620 is coupled with the first resonance rod 20 in the fourth emission filter cavity a4 to form a coupling capacitance between the second coupling part 620 and the first resonance rod 20.

Similarly, the first flying bar 60 disposed between the second emission filter cavity a2 and the fifth emission filter cavity a5, between the fifth emission filter cavity a5 and the a7 of the seventh emission filter cavity, between the seventh emission filter cavity a7 and the tenth emission filter cavity a10, and between the eighth emission filter cavity A8 and the tenth emission filter cavity a10 of the first emission filter branch 12 is similar, and is not repeated here.

A first metal coupling rib 80 is arranged between the first emission filter cavity a1 and the second emission filter cavity a2 of the first emission filter branch 12, and the coupling strength between the first emission filter cavity a1 and the second emission filter cavity a2 on the coupling path of the first emission filter branch 12 can be improved through the first metal coupling rib 80, so that the energy loss is reduced, and the energy transmission quality is improved.

As shown in fig. 4, the filter 10 further includes: the support socket 70 may be disposed on the housing 11, and the support socket 70 is provided with a through hole (not shown), wherein the first connecting portion 630 penetrates through the through hole, and the support socket 70 may fix the first flying bar 60.

The first flying bar 60 of the present embodiment may be implemented by a metal probe, and the support socket 70 may be implemented by PTFE or engineering plastic. If metal flying rods are respectively arranged between the second emission filter cavity A2 and the fifth emission filter cavity A5 of the first emission filter branch 12, between the fifth emission filter cavity A5 and the A7 of the seventh emission filter cavity, between the seventh emission filter cavity A7 and the tenth emission filter cavity A10, and between the eighth emission filter cavity A8 and the tenth emission filter cavity A10, the metal flying rods comprise screws and metal sheets connected with the screws, and the screws are used for fixing the metal sheets on the bottom platforms of the second emission filter cavity A2, the fifth emission filter cavity A5, the seventh emission filter cavity A7, the eighth emission filter cavity A8 and the tenth emission filter cavity A10, the diameter of the bottom platform can be phi 37mm, therefore, the metal flying rods can be used for realizing the diameter between the second emission filter cavity A2 and the fifth emission filter cavity A5, between the fifth emission filter cavity A638A and the seventh emission filter cavity A5, between the fifth emission filter cavity A638A and the seventh emission filter cavity A59623, Capacitive cross coupling between the eighth emission filter cavity A8 and the tenth emission filter cavity a 10.

It can be seen that, the capacitive cross coupling between the second emission filter cavity a2 and the fourth emission filter cavity a4, between the second emission filter cavity a2 and the fifth emission filter cavity a5, between the fifth emission filter cavity a5 and the a7 of the seventh emission filter cavity, between the seventh emission filter cavity a7 and the tenth emission filter cavity a10, and between the eighth emission filter cavity A8 and the tenth emission filter cavity a10 of the first emission filter branch 12 can be realized, five capacitive coupling zeros can be realized, so as to realize zero suppression, if a single-capacitance material is used, the consistency of the capacitive coupling zeros can be good, so as to reduce the production cost.

As shown in FIG. 2, specifically, capacitive cross coupling C is formed between the second emission filter cavity A2 and the fourth emission filter cavity A4₁The second emission filter cavity A2 and the fifth emission filter cavity A5 are capacitively cross-coupled to form a capacitive cross-coupling C₂A capacitive cross coupling between the fifth emission filter cavity A5 and the seventh emission filter cavity A7 to form a capacitive cross coupling C₃The seventh emission filter cavity A7 and the tenth emission filter cavity A10 are capacitively cross-coupled to form a capacitive cross-coupling C₄The eighth emission filter cavity A8 and the tenth emission filter cavity A10 are capacitively cross-coupled to form a capacitive cross-coupling C₅To form the five cross-coupled zeros of the first transmit filter branch 12. The cross coupling zero point is also called a transmission zero point, and the transmission zero point is a transmission function equal to zero, namely, the electromagnetic energy cannot pass through the network at the frequency point corresponding to the transmission zero point, so that the complete isolation effect is achieved, the suppression effect on signals outside a passband is achieved, and the high isolation among a plurality of passbands can be better achieved.

Further, the filter 10 further includes a cover plate (not shown) covering the eight emission filter cavities, and the other end of the first tuning rod 30 is disposed on the cover plate, wherein the first tuning rod 30 may be a metal screw.

In addition, the equivalent circuit of the first transmit filter branch 12 is shown in fig. 5, where the impedance Z1 at the input port is about 50 ohms and the impedance Z2 at the output port is about 50 ohms; in order to ensure that the electromagnetic signals are transmitted between the eleven emission filter cavities of the first emission filter branch 12, impedance adjusters ZV1 are respectively disposed between the input port and the first emission filter cavity a1, between adjacent filter cavities on the coupling path, between non-cascaded filter cavities forming cross coupling, and between the eleventh emission filter cavity a11 and the output port, so as to implement impedance matching.

The bandwidth range of the first transmit filter branch 12 of the filter 10 of the present embodiment is: 1805MHz-1880 MHz. In particular, the coupling bandwidth between the first port of the first transmit filter branch 12 and the first transmit filter cavity a1 ranges from 146Mhz to 166 Mhz; the coupling bandwidth between the first emission filter cavity a1 and the second emission filter cavity a2 ranges from 46Mhz to 56 Mhz; the coupling bandwidth between the second emission filter cavity a2 and the third emission filter cavity A3 ranges from 36Mhz to 45 Mhz; the coupling bandwidth between the second emission filter cavity a2 and the fourth emission filter cavity a4 ranges from (-8.8) Mhz- (-4.1) Mhz; the coupling bandwidth between the second emission filter cavity a2 and the fifth emission filter cavity a5 ranges from (-10) Mhz- (-5.2) Mhz; the coupling bandwidth between the third emission filter cavity A3 and the fourth emission filter cavity a4 ranges from 42Mhz to 51 Mhz; the coupling bandwidth between the fourth emission filter cavity a4 and the fifth emission filter cavity a5 ranges from 34Mhz-42 Mhz; the coupling bandwidth between the fifth emission filter cavity a5 and the sixth emission filter cavity a6 ranges from 33Mhz to 40 Mhz; the coupling bandwidth between the fifth emission filter cavity a5 and the seventh emission filter cavity a7 ranges from (-15) Mhz- (-9.9) Mhz; the coupling bandwidth between the sixth emission filter cavity a6 and the seventh emission filter cavity a7 ranges from 33Mhz to 40 Mhz; the coupling bandwidth between the seventh emission filter cavity a7 and the eighth emission filter cavity A8 ranges from 34Mhz-43 Mhz; the coupling bandwidth between the seventh emission filter cavity a7 and the tenth emission filter cavity a10 ranges from (-7.9) Mhz- (-3.3) Mhz; the coupling bandwidth between the eighth emission filter cavity A8 and the ninth emission filter cavity a9 ranges from 40Mhz to 49 Mhz; the coupling bandwidth between the eighth emission filter cavity A8 and the tenth emission filter cavity a10 ranges from (-9.8) Mhz- (-5) Mhz; the coupling bandwidth between the ninth emission filter cavity a9 and the tenth emission filter cavity a10 ranges from 39Mhz-47 Mhz; the coupling bandwidth between the tenth emission filter cavity a10 and the eleventh emission filter cavity a11 ranges from 58Mhz to 69 Mhz; the coupling bandwidth between the eleventh emission filter cavity a11 and the second port of the first emission filter branch 12 is in the range of 74Mhz-86Mhz, which can meet the design requirement.

Therefore, the resonant frequencies of the first through eleventh emission filter cavities a1 through a11 of the filter 10 are sequentially located in the following ranges: 1848Mhz-1850Mhz, 1843Mhz-1845Mhz, 1835Mhz-1837Mhz, 1842Mhz-1844Mhz, 1841Mhz-1843Mhz, 1827Mhz-1829Mhz, 1841Mhz-1843Mhz, 1842Mhz-1844Mhz, 1833Mhz-1835Mhz, 1841Mhz-1843 Mhz. Therefore, the resonant frequency of each resonant cavity is within the designed bandwidth range, so that the convenience of manufacturing and debugging is improved; the method can be manufactured by adopting similar specification parameters, and the required parameter range can be reached only by simple debugging in the actual process.

The simulation result of the first transmit filter branch 12 is shown in fig. 6, and it can be seen from fig. 6 that the experimental test is shown in the frequency band curve S1.

Fig. 7 is a schematic structural diagram of a second transmitting filter branch of the filter of the present application, and fig. 8 is a schematic structural diagram of a second transmitting filter branch of the embodiment of fig. 7. The filter 10 of the present embodiment further comprises a second transmit filter branch 13. And the second transmitting and filtering branch 13 is arranged on the shell 11 and consists of eight transmitting and filtering cavities which are coupled in sequence.

Specifically, the eight emission filter cavities of the second emission filter branch 13 include a first emission filter cavity B1, a second emission filter cavity B2, a third emission filter cavity B3, a fourth emission filter cavity B4, a fifth emission filter cavity B5, a sixth emission filter cavity B6, a seventh emission filter cavity B7, and an eighth emission filter cavity B8; capacitive cross coupling is respectively formed between the third emission filter cavity B3 and the fifth emission filter cavity B5, between the fifth emission filter cavity B5 and the eighth emission filter cavity B8, and between the sixth emission filter cavity B6 and the eighth emission filter cavity B8; wherein the bandwidth of the second transmitting and filtering branch 13 is in the range of 2110MHz-2170 MHz.

It can be seen that, capacitive cross coupling is respectively performed between the third emission filter cavity B3 and the fifth emission filter cavity B5, between the fifth emission filter cavity B5 and the eighth emission filter cavity B8, and between the sixth emission filter cavity B6 and the eighth emission filter cavity B8 of the second emission filter branch 13, so that high-end suppression of the bandwidth of the second emission filter branch can be well controlled to obtain better high-end suppression of the bandwidth, and low-end suppression of the bandwidth of the second emission filter branch can be well controlled to obtain better low-end suppression of the bandwidth, and therefore, the stop-band suppression performance of the filter 10 can be improved; in addition, the bandwidth of the second transmitting and filtering branch 13 ranges from 2110MHz to 2170MHz, and the bandwidth of the second transmitting and filtering branch 13 can be precisely controlled.

Alternatively, as shown in fig. 7, the eight emission filter cavities of the second emission filter branch 13 are divided into two rows arranged along a second direction y, and the second direction y is perpendicular to the first direction x; the first emission filter cavity B1, the second emission filter cavity B2, the third emission filter cavity B3, the fifth emission filter cavity B5 and the eighth emission filter cavity B8 of the second emission filter branch 13 are in a row and are sequentially arranged along the first direction x; the fourth emission filter cavity B4, the sixth emission filter cavity B6 and the seventh emission filter cavity B7 of the second emission filter branch 13 are in a row and are sequentially arranged along the first direction x.

It can be seen that the eight emission filter cavities are divided into two rows arranged in sequence along the second direction y, and the eight emission filter cavities are regularly arranged, so as to reduce the volume of the second emission filter branch 13, and further reduce the volume of the filter 10.

Optionally, as shown in fig. 7, eight emission filter cavities of the second emission filter branch 13 are sequentially window-coupled, that is, the first emission filter cavity B1 and the second emission filter cavity B2 are window-coupled, the second emission filter cavity B2 and the third emission filter cavity B3 are window-coupled, the third emission filter cavity B3 and the fourth emission filter cavity B4 are window-coupled, the fourth emission filter cavity B4 and the fifth emission filter cavity B5 are window-coupled, the fifth emission filter cavity B5 and the sixth emission filter cavity B6 are window-coupled, the sixth emission filter cavity B6 and the seventh emission filter cavity B7 are window-coupled, and the seventh emission filter cavity B7 and the eighth emission filter cavity B8 are window-coupled.

Therefore, the two adjacent filter cavities on the coupling path of the second transmitting filter branch 13 are coupled by pure windows, so that the cost of the filter 10 can be reduced.

The capacitive cross coupling between the third emission filter cavity B3 and the fifth emission filter cavity B5, between the fifth emission filter cavity B5 and the eighth emission filter cavity B8, and between the sixth emission filter cavity B6 and the eighth emission filter cavity B8 of the second emission filter branch 13 can be realized, so that three capacitive coupling zeros can be realized, thereby realizing zero suppression, if a single-capacitance material is adopted, the consistency of the capacitive coupling zeros can be good, and the production cost can be reduced.

As shown in FIG. 8, specifically, the third emission filter cavity B3 and the fifth emission filter cavity B5 are capacitively cross-coupled to form a capacitive cross-coupling C₆The fifth emission filter cavity B5 and the eighth emission filter cavity B8 are capacitively cross-coupled to form a capacitive cross-coupling C₇The sixth emission filter cavity B6 and the eighth emission filter cavity B8 are capacitively cross-coupled to form a capacitive cross-coupling C₈To form the three cross-coupled zeros of the second transmit filter branch 13.

Each emission filter cavity on the second emission filter branch 13 is provided with a second mounting column, a second resonance rod 21 and a second tuning rod 31; a second resonant rod 21 including a second U-shaped sidewall and a second hollow cavity formed by the second U-shaped sidewall; a second tuning rod 31, one end of the second tuning rod 31 is arranged in the second hollow inner cavity; the two ends of the second U-shaped side wall bend and extend in the direction departing from the second hollow inner cavity so as to form second disc-shaped structures at the two ends of the second U-shaped side wall, and the second disc-shaped structures are arranged in parallel with the bottom of the second U-shaped side wall; the second U-shaped side wall is fixed to the second mounting post.

The structural schematic diagram of the combined structure of the second tuning rod 31, the second resonant rod 21 and the second mounting post of the second transmitting and filtering branch 13 is similar to the structural schematic diagram of the combined structure of the first tuning rod 30, the first resonant rod 20 and the first mounting post 40 of the first transmitting and filtering branch 12, as shown in fig. 3, and is not repeated herein. Thus, the second resonant rod 21 is fixed to the housing 11 by the second mounting post, and the resonant frequency of each of the emission filter cavities in the second emission filter branch 13 can be adjusted by adjusting the depth of the second tuning rod 31 within the second hollow cavity.

The eight emission filter cavities of the second emission filter branch 13 have the same size, so that the production is convenient, and the cost is saved. The radius of the eight emission filter cavities may be less than 23mm, e.g., 23mm, 22mm, 21mm, etc.

Second flying rods are respectively arranged between the third emission filter cavity B3 and the fifth emission filter cavity B5, between the fifth emission filter cavity B5 and the eighth emission filter cavity B8, and between the sixth emission filter cavity B6 and the eighth emission filter cavity B8 of the second emission filter branch circuit 13; the second flying rod comprises a third coupling part, a fourth coupling part and a second connecting part, and two ends of the second connecting part are connected with the third coupling part and the fourth coupling part respectively. The second flying rod can be arranged in a sheet shape, and is simple in structure and convenient to process and manufacture.

Specifically, the schematic structural diagram of the combined structure of the second flying bar, the third coupling portion, the fourth coupling portion and the second connecting portion of the second emission filtering branch 13 is similar to the schematic structural diagram of the combined structure of the first flying bar, the first coupling portion, the second coupling portion and the first connecting portion of the first emission filtering branch 12, as shown in fig. 4, and is not repeated here.

In addition, the equivalent circuit of the second transmitting filter branch 13 is shown in fig. 9, and the impedance Z3 at the input port is about 50 ohms, and the impedance Z4 at the output port is about 50 ohms; in order to ensure that the electromagnetic signals are transmitted between the eight emission filter cavities of the second emission filter branch 13, impedance adjusters ZV2 are respectively required to be arranged between the input port and the first emission filter cavity B1, between adjacent filter cavities on the coupling path, between non-cascaded filter cavities forming cross coupling, and between the eighth emission filter cavity B8 and the output port, so as to realize impedance matching.

The bandwidth range of the second transmitting filter branch 13 of the filter 10 of the present embodiment is: 2110MHz to 2170 MHz. Specifically, the coupling bandwidth between the first port of the second emission filter branch 13 and the first emission filter cavity B1 is in the range of 62Mhz-73 Mhz; the coupling bandwidth between the first emission filter cavity B1 and the second emission filter cavity B2 ranges from 49Mhz to 59 Mhz; the coupling bandwidth between the second emission filter cavity B2 and the third emission filter cavity B3 ranges from 34Mhz-42 Mhz; the coupling bandwidth between the third emission filter cavity B3 and the fourth emission filter cavity B4 ranges from 31Mhz to 38 Mhz; the coupling bandwidth between the third emission filter cavity B3 and the fifth emission filter cavity B5 ranges from (-6) Mhz- (-1.6) Mhz; the coupling bandwidth between the fourth emission filter cavity B4 and the fifth emission filter cavity B5 ranges from 30Mhz to 38 Mhz; the coupling bandwidth between the fifth emission filter cavity B5 and the sixth emission filter cavity B6 ranges from 23Mhz to 30 Mhz; the coupling bandwidth between the sixth emission filter cavity B6 and the seventh emission filter cavity B7 ranges from 49Mhz to 59 Mhz; the coupling bandwidth between the sixth emission filter cavity B6 and the eighth emission filter cavity B8 ranges from (-2.4) Mhz- (-2) Mhz; the coupling bandwidth between the seventh emission filter cavity B7 and the eighth emission filter cavity B8 ranges from 42Mhz to 51 Mhz; the coupling bandwidth between the eighth emission filter cavity B8 and the second port of the second emission filter branch 13 is in the range of 62Mhz-73Mhz, which can meet the design requirement.

Therefore, the resonant frequencies of the first through eighth transmission-filter cavities B1-B8 of the filter 10 are in the following ranges in order: 2139Mhz-2141Mhz, 2135Mhz-2137Mhz, 2139Mhz-2141Mhz, 2138Mhz-2140Mhz, 2139Mhz-2141 Mhz. Therefore, the resonant frequency of each resonant cavity is within the designed bandwidth range, so that the convenience of manufacturing and debugging is improved; the method can be manufactured by adopting similar specification parameters, and the required parameter range can be reached only by simple debugging in the actual process.

Furthermore, the simulation result of the second transmitting and filtering branch 13 is shown in fig. 6, and it can be seen from fig. 6 that, through experimental tests, as shown by the frequency band curve S1, in combination with the first transmitting and filtering branch 12, there are four low-end coupling zero points a, b, c, d and three high-end coupling zero points e, f, g. The first transmit filter branch 12 has five capacitive cross-coupling zeros and the second transmit filter branch 13 has three capacitive cross-coupling zeros, but since the same rf parameters of the zeros will result in the same simulation points, only seven cross-coupling zeros are shown in the simulation. The transmit filter branch comprises a first transmit filter branch 12 and a second transmit filter branch 13. The inhibition of the transmitting and filtering branch at the frequency point 1.705GHz (m3) is-0.951 dB, the inhibition of the transmitting and filtering branch at the frequency point 1.785GHz (m9) is-0.983 dB, the inhibition of the transmitting and filtering branch at the frequency point 1.805GHz (m10) is-81.781 dB, the inhibition of the transmitting and filtering branch at the frequency point 1.920GHz (m22) is-0.973 dB, the inhibition of the transmitting and filtering branch at the frequency point 1.980GHz (m23) is-1.133 dB, the inhibition of the transmitting and filtering branch at the frequency point 1.877GHz (m24) is-94.235 dB, and the inhibition of the transmitting and filtering branch at the frequency point 2.025GHz (m25) is-64.277 dB. Therefore, the design requirement of out-of-band rejection of the transmitting filter branch can be met.

Referring to fig. 10 and fig. 11, fig. 10 is a schematic diagram of a first receiving filter branch of the filter of the present application, and fig. 11 is a schematic diagram of a topology structure of the first receiving filter branch in the embodiment of fig. 10. The filter 10 further includes a first receiving filter branch 14 disposed on the housing 11 and composed of nine receiving filter cavities coupled in sequence.

Specifically, the nine receiving filter cavities of the first receiving filter branch 14 include a first receiving filter cavity C1, a second receiving filter cavity C2, a third receiving filter cavity C3, a fourth receiving filter cavity C4, a fifth receiving filter cavity C5, a sixth receiving filter cavity C6, a seventh receiving filter cavity C7, an eighth receiving filter cavity C8, and a ninth receiving filter cavity C9.

Inductive cross coupling is respectively performed between the second receiving filter cavity C2 and the fourth receiving filter cavity C4, between the second receiving filter cavity C2 and the fifth receiving filter cavity C5, and between the sixth receiving filter cavity C6 and the eighth receiving filter cavity C8 of the first receiving filter branch 14, wherein the bandwidth range of the first receiving filter branch 14 is 1710MHz-1785 MHz.

Specifically, as shown in fig. 11, the second receiving filter cavity C2 and the fourth receiving filter cavity C4 of the first receiving filter branch 14 are inductively cross-coupled to form an inductive cross-coupling zero L₁The second receiving filter cavity C2 and the fifth receiving filter cavity C5 of the first receiving filter branch 14 are inductively cross-coupled to form an inductive cross-coupling zero L₂The sixth receiving filter cavity C6 and the eighth receiving filter cavity C8 of the first receiving filter branch 14 are inductively cross-coupled to form an inductive cross-coupling zero L₃To form the three inductive cross-coupling zeros of the first receive filter branch 14.

It can be seen that, between the second receiving filter cavity C2 and the fourth receiving filter cavity C4, between the second receiving filter cavity C2 and the fifth receiving filter cavity C5, and between the sixth receiving filter cavity C6 and the eighth receiving filter cavity C8 of the first receiving filter branch 14 are inductively cross-coupled, so as to form three inductive cross-coupling zeros, which can well control the high-end rejection of the bandwidth of the first receiving filter branch, so as to obtain a better high-end rejection of the bandwidth, and can well control the low-end rejection of the bandwidth of the first receiving filter branch, so as to obtain a better low-end rejection of the bandwidth, and therefore, the stop-band rejection performance of the filter can be improved; in addition, the bandwidth of the first receiving and filtering branch 14 ranges from 1710MHz to 1785MHz, and the bandwidth of the first receiving and filtering branch 14 can be accurately controlled.

Optionally, the first receiving filtering branch 14 is divided into three columns arranged along the second direction y; the second receiving filter cavity C2, the fifth receiving filter cavity C5, the sixth receiving filter cavity C6, the eighth receiving filter cavity C8 and the ninth receiving filter cavity C9 of the first receiving filter branch 14 are in a row and are sequentially arranged along the first direction x; the first receiving filter cavities C1 of the first receiving filter branch 14 are in a row, and the straight line formed by connecting the first receiving filter cavity C1 and the second receiving filter cavity C2 of the first receiving filter branch 14 and the second receiving filter cavity C2, the fifth receiving filter cavity C5, the sixth receiving filter cavity C6, the eighth receiving filter cavity C8 and the ninth receiving filter cavity C9 of the first receiving filter branch 14 are in a row and are connected to form a straight line, and the included angle is an acute angle, which may be 5 °, 10 ° or 30 °, specifically determined according to actual conditions; the third receiving filter cavity C3, the fourth receiving filter cavity C4 and the seventh receiving filter cavity C7 of the first receiving filter branch 14 are in a row and are sequentially arranged along the first direction x.

It can be seen that the first receiving filter branch 14 is divided into three rows arranged in sequence along the second direction y, and nine receiving filter cavities are regularly arranged, so as to reduce the volume of the first receiving filter branch 14, and thus the volume of the filter 10.

Optionally, nine receiving filter cavities of the first receiving filter branch 14 are sequentially window-coupled, that is, a window coupling is performed between the first receiving filter cavity C1 and the second receiving filter cavity C2, a window coupling is performed between the second receiving filter cavity C2 and the third receiving filter cavity C3, a window coupling is performed between the third receiving filter cavity C3 and the fourth receiving filter cavity C4, a window coupling is performed between the fourth receiving filter cavity C4 and the fifth receiving filter cavity C5, a window coupling is performed between the fifth receiving filter cavity C5 and the sixth receiving filter cavity C6, a window coupling is performed between the sixth receiving filter cavity C6 and the seventh receiving filter cavity C7, a window coupling is performed between the seventh receiving filter cavity C7 and the eighth receiving filter cavity C8, and a window coupling is performed between the eighth receiving filter cavity C8 and the ninth receiving filter cavity C9.

The two adjacent filter cavities on the coupling path of the first receiving filter branch 14 are in pure window coupling, so that the cost of the filter 10 is reduced.

Metal coupling ribs are respectively arranged between the second receiving filter cavity C2 and the fourth receiving filter cavity C4, between the second receiving filter cavity C2 and the fifth receiving filter cavity C5, and between the sixth receiving filter cavity C6 and the eighth receiving filter cavity C8 of the first receiving filter branch 14, and inductive cross coupling can be realized through the metal coupling ribs.

In addition, the second metal coupling ribs 81 are respectively disposed between the first receiving filter cavity C1 and the second receiving filter cavity C2, between the second receiving filter cavity C2 and the fourth receiving filter cavity C4, between the fourth receiving filter cavity C4 and the fifth receiving filter cavity C5, between the fifth receiving filter cavity C5 and the sixth receiving filter cavity C6, between the sixth receiving filter cavity C6 and the seventh receiving filter cavity C7, between the sixth receiving filter cavity C6 and the eighth receiving filter cavity C8, and between the eighth receiving filter cavity C8 and the ninth receiving filter cavity C9 of the first receiving filter branch 14.

Therefore, the coupling strength between the first receiving filter cavity C1 and the second receiving filter cavity C2, between the second receiving filter cavity C2 and the fourth receiving filter cavity C4, between the fourth receiving filter cavity C4 and the fifth receiving filter cavity C5, between the fifth receiving filter cavity C5 and the sixth receiving filter cavity C6, between the sixth receiving filter cavity C6 and the seventh receiving filter cavity C7, between the sixth receiving filter cavity C6 and the eighth receiving filter cavity C8, and between the eighth receiving filter cavity C8 and the ninth receiving filter cavity C9 in the coupling path of the first receiving filter branch 14 can be improved by adding the second metal coupling rib 81, so that the loss of energy is reduced, and the quality of energy transmission is improved.

Each receiving filter cavity on the first receiving filter branch 14 is provided with a third mounting column, a third resonance rod 22 and a third tuning rod 32; a third resonant bar 22 comprising a third U-shaped sidewall and a third hollow interior formed by the third U-shaped sidewall; a third tuning rod 32, one end of the third tuning rod 32 being disposed within the third hollow interior; the two ends of the third U-shaped side wall bend and extend in the direction departing from the third hollow inner cavity so as to form third disc-shaped structures at the two ends of the third U-shaped side wall, and the third disc-shaped structures are arranged in parallel with the bottom of the third U-shaped side wall; the third U-shaped side wall is fixed to the third mounting post.

The schematic structural diagram of the combined structure of the third tuning rod 32, the third resonant rod 22 and the third mounting post of the first receiving and filtering branch 14 is similar to the schematic structural diagram of the combined structure of the first tuning rod 30, the first resonant rod 20 and the first mounting post 40 of the first transmitting and filtering branch 12, as shown in fig. 3, and is not repeated herein.

Thus, the third resonant rod 22 is fixed to the housing 11 by the third mounting post, and the resonant frequency of the third resonant cavity can be adjusted by adjusting the depth of the third tuning rod 32 within the third hollow cavity.

Nine receiving filter cavities of the first receiving filter branch 14 are the same in size, so that the production is convenient, and the cost is saved. The radius of the nine receiving filter cavities may be less than 23mm, e.g. 23mm, 22mm, 21mm, etc.

The equivalent circuit of the first receiving filtering branch 14 is shown in fig. 12, with an impedance Z5 at the input port of about 50 ohms and an impedance Z6 at the output port of about 50 ohms; in order to ensure that the electromagnetic signals are transmitted between the nine receiving filter cavities of the first receiving filter branch 14, impedance adjusters ZV3 are required to be respectively arranged between the input port and the first receiving filter cavity C1, between adjacent filter cavities on the coupling path, between non-cascaded filter cavities forming cross coupling, and between the ninth receiving filter cavity C9 and the output port, so as to realize impedance matching.

The bandwidth range of the first receiving filtering branch 14 of the filter 10 of the present embodiment is: 1710MHz-1785 MHz. Specifically, the coupling bandwidth between the first port of the first receiving filtering branch 14 and the first receiving filtering cavity C1 ranges from 157Mhz to 179 Mhz; the coupling bandwidth between the first receiving filter cavity C1 and the second receiving filter cavity C2 ranges from 55Mhz to 65 Mhz; the coupling bandwidth between the second receiving filter cavity C2 and the third receiving filter cavity C3 ranges from 27Mhz to 34 Mhz; the coupling bandwidth between the second receiving filter cavity C2 and the fourth receiving filter cavity C4 ranges from 34Mhz to 42 Mhz; the coupling bandwidth between the second receiving filter cavity C2 and the fifth receiving filter cavity C5 ranges from 8.1Mhz to 13 Mhz; the coupling bandwidth between the third receiving filter cavity C3 and the fourth receiving filter cavity C4 ranges from 20Mhz to 26 Mhz; the coupling bandwidth between the fourth receiving filter cavity C4 and the fifth receiving filter cavity C5 ranges from 42Mhz to 51 Mhz; the coupling bandwidth between the fifth receiving filter cavity C5 and the sixth receiving filter cavity C6 ranges from 43Mhz to 52 Mhz; the coupling bandwidth between the sixth receiving filter cavity C6 and the seventh receiving filter cavity C7 ranges from 37Mhz to 45 Mhz; the coupling bandwidth between the sixth receiving filter cavity C6 and the eighth receiving filter cavity C8 ranges from 23Mhz to 30 Mhz; the coupling bandwidth between the seventh receiving filter cavity C7 and the eighth receiving filter cavity C8 ranges from 41Mhz to 50 Mhz; the coupling bandwidth between the eighth receiving filter cavity C8 and the ninth receiving filter cavity C9 ranges from 70Mhz to 82 Mhz; the coupling bandwidth between the ninth receiving filter cavity C9 and the second port of the first receiving filter branch 14 is in the range of 89Mhz-103Mhz, which can meet the design requirement.

Therefore, the resonant frequencies of the first through ninth receiving filter cavities C1 through C9 of the filter 10 are sequentially located in the following ranges: 1740Mhz-1742Mhz, 1745Mhz-1747Mhz, 1785Mhz-1787Mhz, 1754Mhz-1756Mhz, 1746Mhz-1748Mhz, 1773Mhz-1775Mhz, 1748Mhz-1750 Mhz. Therefore, the resonant frequency of each resonant cavity is within the designed bandwidth range, so that the convenience of manufacturing and debugging is improved; the method can be manufactured by adopting similar specification parameters, and the required parameter range can be reached only by simple debugging in the actual process.

The simulation result of the first receiving and filtering branch 14 is shown in fig. 6, and it can be seen from fig. 6 that the experimental test is performed, as shown by the frequency band curve S2.

Referring to fig. 13 and 14, fig. 13 is a schematic diagram of a second receiving filter branch of the filter of the present application, and fig. 14 is a schematic diagram of a topology structure of the second receiving filter branch of the embodiment of fig. 13. The filter 10 further includes a second receiving filter branch 15 disposed on the housing 11, and composed of seven receiving filter cavities coupled in sequence.

Specifically, the seven receiving filter cavities of the second receiving filter branch 15 include a first receiving filter cavity D1, a second receiving filter cavity D2, a third receiving filter cavity D3, a fourth receiving filter cavity D4, a fifth receiving filter cavity D5, a sixth receiving filter cavity D6, and a seventh receiving filter cavity D7.

Capacitive cross coupling is respectively carried out between the first receiving filter cavity D1 and the third receiving filter cavity D3, between the fourth receiving filter cavity D4 and the sixth receiving filter cavity D6, and between the fourth receiving filter cavity D4 and the seventh receiving filter cavity D7 of the second receiving filter branch 15, wherein the bandwidth of the second receiving filter branch 15 is in the range of 1920MHz-1980 MHz.

Specifically, as shown in fig. 14, the first receiving filter cavity D1 and the third receiving filter cavity D3 of the second receiving filter branch 15 are capacitively cross-coupled to form a capacitive cross-coupling zero point C₉And the fourth receiving filter cavity D4 and the sixth receiving filter cavity D6 are capacitively cross-coupled to form a capacitive cross-coupling zero point C₁₀And the fourth receiving filter cavity D4 and the seventh receiving filter cavity D7 are capacitively cross-coupled to form a capacitive cross-coupling zero point C₁₁To form the three capacitive cross-coupling zeros of the second receive filter branch 15.

It can be seen that, capacitive cross coupling is respectively performed between the first receiving filter cavity D1 and the third receiving filter cavity D3, between the fourth receiving filter cavity D4 and the sixth receiving filter cavity D6, and between the fourth receiving filter cavity D4 and the seventh receiving filter cavity D7 of the second receiving filter branch 15, so as to form three capacitive cross coupling zeros, which can well control the high-end rejection of the bandwidth of the second receiving filter branch, so as to obtain better high-end rejection of the bandwidth, and can well control the low-end rejection of the bandwidth of the second receiving filter branch, so as to obtain better low-end rejection of the bandwidth, and therefore, the stop-band rejection performance of the filter can be improved; furthermore, the bandwidth of the second receiving filtering branch 15 is in the range of 1920MHz-1980MHz, which enables to precisely control the bandwidth of the second receiving filtering branch 15.

Optionally, the second receiving filtering branch 15 is divided into three columns arranged along the second direction y; the second receiving filter cavity D2, the fourth receiving filter cavity D4 and the sixth receiving filter cavity D6 of the second receiving filter branch 15 are in a row and are sequentially arranged along the first direction x; the seventh receiving filter cavities D7 of the second receiving filter branch 15 are a row sequentially arranged in the first direction x, and the seventh receiving filter cavity D7, the fourth receiving filter cavity D4 and the third receiving filter cavity D3 are arranged in a straight line.

It can be seen that the second receiving filter branch 15 is divided into three rows arranged in sequence along the second direction y, and seven receiving filter cavities are regularly arranged, so as to reduce the volume of the second receiving filter branch 15, and thus the volume of the filter 10.

Optionally, seven receiving filter cavities of the second receiving filter branch 15 are sequentially window-coupled, that is, a window coupling is performed between the first receiving filter cavity D1 and the second receiving filter cavity D2, a window coupling is performed between the second receiving filter cavity D2 and the third receiving filter cavity D3, a window coupling is performed between the third receiving filter cavity D3 and the fourth receiving filter cavity D4, a window coupling is performed between the fourth receiving filter cavity D4 and the fifth receiving filter cavity D5, a window coupling is performed between the fifth receiving filter cavity D5 and the sixth receiving filter cavity D6, and a window coupling is performed between the sixth receiving filter cavity D6 and the seventh receiving filter cavity D7.

And pure window coupling is adopted between two adjacent filter cavities on the coupling path of the second receiving filter branch circuit 15, so that the cost of the filter 10 is reduced.

In addition, the third metal coupling ribs 82 are respectively disposed between the first receiving filter cavity D1 and the second receiving filter cavity D2, between the second receiving filter cavity D2 and the third receiving filter cavity D3, and between the fourth receiving filter cavity D4 and the fifth receiving filter cavity D5 of the second receiving filter branch 15.

Therefore, the third metal coupling rib 82 can improve the coupling strength between the first receiving filter cavity D1 and the second receiving filter cavity D2, between the second receiving filter cavity D2 and the third receiving filter cavity D3, and between the fourth receiving filter cavity D4 and the fifth receiving filter cavity D5 in the coupling path of the second receiving filter branch 15, thereby reducing the energy loss and improving the quality of energy transmission.

Each receiving filter cavity is provided with a fourth mounting post, a fourth resonant rod 23 and a fourth tuning rod 33; a fourth resonant rod 23 including a fourth U-shaped sidewall and a fourth hollow interior formed by the fourth U-shaped sidewall; a fourth tuning rod 33, one end of the fourth tuning rod 33 being disposed within the fourth hollow cavity; the two ends of the fourth U-shaped side wall bend and extend in the direction departing from the fourth hollow inner cavity so as to form fourth disc-shaped structures at the two ends of the fourth U-shaped side wall, and the fourth disc-shaped structures are arranged in parallel with the bottom of the fourth U-shaped side wall; the fourth U-shaped side wall is fixed to the fourth mounting post.

The schematic structural diagram of the combined structure of the fourth tuning rod 33, the fourth resonant rod 23 and the fourth mounting post of the second receiving filtering branch 15 is similar to the schematic structural diagram of the combined structure of the first tuning rod 30, the first resonant rod 20 and the first mounting post 40 of the first transmitting filtering branch 12, as shown in fig. 3, and is not repeated herein.

Thus, the fourth resonant rod 23 is fixed to the housing 11 by the fourth mounting post, and the resonant frequency of the fourth resonant cavity can be adjusted by adjusting the depth of the fourth tuning rod 33 within the fourth hollow cavity.

Seven receiving filter cavities of the second receiving filter branch circuit 15 have the same size, so that the production is convenient, and the cost is saved. The radius of the seven receiving filter cavities may be less than 23mm, e.g. 23mm, 22mm, 21mm, etc.

Third flying rods are respectively arranged between the first receiving filter cavity D1 and the third receiving filter cavity D3, between the fourth receiving filter cavity D4 and the sixth receiving filter cavity D6, and between the fourth receiving filter cavity D4 and the seventh receiving filter cavity D7 of the second receiving filter branch circuit 15; the third flying bar comprises a fifth coupling part, a sixth coupling part and a third connecting part, and two ends of the third connecting part are connected with the fifth coupling part and the sixth coupling part respectively. The third flying rod can be arranged in a sheet shape, and the structure is simple, and the processing and the manufacturing are convenient.

Specifically, the schematic structure diagram of the combined structure of the third flying bar, the fifth coupling portion, the sixth coupling portion and the third connecting portion of the second receiving filtering branch 15 is similar to the schematic structure diagram of the combined structure of the first flying bar, the first coupling portion, the second coupling portion and the first connecting portion of the first transmitting filtering branch 12, as shown in fig. 4, and is not repeated here.

The equivalent circuit of the second receiving filtering branch 15 is shown in fig. 15, with an impedance Z7 at the input port of about 50 ohms and an impedance Z8 at the output port of about 50 ohms; in order to ensure that the electromagnetic signal is transmitted between the seven receiving filter cavities of the second receiving filter branch 15, impedance adjusters ZV4 are respectively arranged between the input port and the first receiving filter cavity D1, between adjacent filter cavities on the coupling path, between non-cascaded filter cavities forming cross coupling, and between the seventh receiving filter cavity D7 and the output port, so as to realize impedance matching.

The bandwidth range of the second receiving filtering branch 15 of the filter 10 of the present embodiment is: 1920MHz-1980 MHz. In particular, the coupling bandwidth between the first port of the second receiving filtering branch 15 and the first receiving filtering cavity D1 ranges from 472Mhz to 529 Mhz; the coupling bandwidth between the first receiving filter cavity D1 and the second receiving filter cavity D2 ranges from 169Mhz to 192 Mhz; the coupling bandwidth between the second receiving filter cavity D2 and the third receiving filter cavity D3 ranges from 47Mhz to 57 Mhz; the coupling bandwidth between the second receiving filter cavity D2 and the fourth receiving filter cavity D4 ranges from (-16) Mhz- (-11) Mhz; the coupling bandwidth between the third receiving filter cavity D3 and the fourth receiving filter cavity D4 ranges from 35Mhz to 43 Mhz; the coupling bandwidth between the fourth receiving filter cavity D4 and the fifth receiving filter cavity D5 ranges from 34Mhz to 42 Mhz; the coupling bandwidth between the fifth receiving filter cavity D5 and the sixth receiving filter cavity D6 ranges from 33Mhz to 41 Mhz; the coupling bandwidth between the fifth receiving filter cavity D5 and the eighth receiving filter cavity D8 ranges from (-9.6) Mhz- (-4.8) Mhz; the coupling bandwidth between the sixth receiving filter cavity D6 and the seventh receiving filter cavity D7 ranges from 41Mhz to 49 Mhz; the coupling bandwidth between the sixth receiving filter cavity D6 and the eighth receiving filter cavity D8 ranges from 3.9Mhz to 8.5 Mhz; the coupling bandwidth between the seventh receiving filter cavity D7 and the eighth receiving filter cavity D8 ranges from 53Mhz to 63 Mhz; the coupling bandwidth between the eighth receiving filter cavity D8 and the second port of the second receiving filter branch 15 is in the range of 68Mhz-80Mhz, which can meet the design requirement.

Therefore, the resonant frequencies of the first to eighth receiving filter cavities D1 to D8 of the filter 10 are sequentially located in the following ranges: 2039Mhz-2041Mhz, 1955Mhz-1957Mhz, 1939Mhz-1941Mhz, 1950Mhz-1952Mhz, 1949Mhz-1951Mhz, 1953Mhz-1955Mhz, 1949Mhz-1951Mhz, and 1949Mhz-1951 Mhz. Therefore, the resonant frequency of each resonant cavity is within the designed bandwidth range, so that the convenience of manufacturing and debugging is improved; the method can be manufactured by adopting similar specification parameters, and the required parameter range can be reached only by simple debugging in the actual process.

The simulation result of the second receiving and filtering branch 15 is shown in fig. 6, and it can be seen from fig. 6 that, through experimental tests, as shown by the frequency band curve S2, in combination with the first receiving and filtering branch 14, there are three low-end coupling zero points h, i, j and three high-end coupling zero points k, l, m. The receiving filtering branch comprises a first receiving filtering branch 14 and a second receiving filtering branch 15. The suppression of the receiving filter branch at the frequency point 1.805GHz (m16) is-1.343 dB, the suppression of the receiving filter branch at the frequency point 1.880GHz (m17) is-1.154 dB, the suppression of the receiving filter branch at the frequency point 1.780GHz (m20) is-109.436 dB, the suppression of the receiving filter branch at the frequency point 1.913GHz (m21) is-108.821 dB, the suppression of the receiving filter branch at the frequency point 2.170GHz (m26) is-1.031 dB, the suppression of the receiving filter branch at the frequency point 2.110GHz (m27) is-1.039 dB, the suppression of the receiving filter branch at the frequency point 2.090GHz (m28) is-36.821 dB, and the suppression of the receiving filter branch at the frequency point 2.180GHz (m29) is-23.464 dB, so that the filtering of the receiving branch can meet the design requirement of suppression.

Referring to fig. 16, fig. 16 is a schematic diagram of an equivalent circuit structure of a filter formed by combining a first transmitting filter branch, a second transmitting filter branch, a first receiving filter branch and a second receiving filter branch. The filter 10 includes a first transmitting filter branch 12, a second transmitting filter branch 13, a first receiving filter branch 14, a second receiving filter branch 15, an input common port, a first output port, and a second output port.

The first transmitting filter cavity a1 of the first transmitting filter branch 12 is connected to the first receiving filter cavity B1 of the first receiving filter branch 14 and the first receiving filter cavity D1 of the second receiving filter branch 15 and coupled to the first transmitting filter cavity B1 of the second transmitting filter branch 13 to the input common of the filter 10; the eighth transmitting filter cavity B8 of the second transmitting filter branch 13 is connected to the eleventh transmitting filter cavity a11 of the first transmitting filter branch 12 and coupled to the first output terminal of the filter 10; the ninth receiving filter cavity C9 of the first receiving filter branch 12 is connected to the seventh receiving filter cavity D7 of the second receiving filter branch 15 and coupled to the second output terminal of the filter 10. Therefore, the first transmitting filter branch 12, the second transmitting filter branch 13, the first receiving filter branch 14 and the second receiving filter branch 15 share the common input terminal, so that the cost can be saved and the size of the filter 10 can be reduced.

The filter 10 is a microwave filter applied to a 5G mobile communication system, the working frequency band of a first transmitting and filtering branch is 1805MHz-1880MHz, the working frequency band of a second transmitting and filtering branch is 2110MHz-2170MHz, the working frequency band of a first receiving and filtering branch is 1710MHz-1785MHz, and the working frequency band of a second receiving and filtering branch is 1920MHz-1980MHz, and has the characteristics of strong anti-interference capability, small overall size and light weight.

The filter 10 in the embodiment of the application has low loss, and can ensure low energy consumption of the communication module; the first transmitting and filtering branch of the filter 10 is designed by combining 11-order resonant cavities, the second transmitting and filtering branch is designed by combining 8-order resonant cavities, the first receiving and filtering branch of the filter 10 is designed by combining 9-order resonant cavities, the second receiving and filtering branch is designed by combining 7-order resonant cavities, and a coupling zero structure is introduced, so that the high-interference-resistance capability is realized, and the communication system can be ensured not to be interfered by stray signals; the filter 10 is simple in design scheme, low in cost, and good in structure and stable in electrical performance.

The present application further provides a communication device, as shown in fig. 17, fig. 17 is a schematic structural diagram of an embodiment of the communication device of the present application. The communication device of the present embodiment includes an antenna 92 and a radio frequency unit 91 connected to the antenna 92, the radio frequency unit 91 includes a filter 10 as shown in the above-mentioned embodiment, and the filter 10 is used for filtering a radio frequency signal.

In other embodiments, the rf Unit 91 may be integrated with the Antenna 92 to form an Active Antenna Unit (AAU).

Some embodiments of the present application are referred to as filters and may also be referred to as combiners, i.e., dual-frequency combiners. It is understood that in other embodiments, the duplexer may be referred to as a duplexer.

The above description is only for the purpose of illustrating embodiments of the present application and is not intended to limit the scope of the present application, and all modifications of equivalent structures and equivalent processes, which are made by the contents of the specification and the drawings of the present application or are directly or indirectly applied to other related technical fields, are also included in the scope of the present application.

Claims

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

a housing;

2. The filter of claim 1, wherein the first transmit filter cavity of the first transmit filter branch is connected to the first receive filter cavity of the first receive filter branch and the first receive filter cavity of the second receive filter branch and coupled to the first transmit filter cavity of the second transmit filter branch at an input common of the filter;

the eighth emission filter cavity of the second emission filter branch is connected with the eleventh emission filter cavity of the first emission filter branch and is coupled with the first output end of the filter;

the ninth receiving filter cavity of the first receiving filter branch is connected with the seventh receiving filter cavity of the second receiving filter branch and is coupled with the second output end of the filter;

the bandwidth range of the first transmitting and filtering branch circuit is 1805MHz-1880 MHz;

the bandwidth range of the second transmitting and filtering branch is 2110MHz-2170 MHz;

the bandwidth range of the first receiving filtering branch circuit is 1710MHz-1785 MHz;

the bandwidth of the second receiving and filtering branch is in the range of 1920MHz-1980 MHz.

3. The filter according to claim 1, wherein the eleven emission filter cavities of the first emission filter branch are divided into two rows arranged along a second direction, the second direction being perpendicular to the first direction;

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

and the third emission filtering cavity, the fourth emission filtering cavity, the sixth emission filtering cavity, the eighth emission filtering cavity and the ninth emission filtering cavity of the first emission filtering branch are in a row and are sequentially arranged along the first direction.

4. The filter of claim 3, wherein eleven transmit filter cavities of the first transmit filter branch are sequentially window-coupled;

first flying rods are respectively arranged between a second emission filtering cavity and a fourth emission filtering cavity, between the second emission filtering cavity and a fifth emission filtering cavity, between the fifth emission filtering cavity and a seventh emission filtering cavity, between the seventh emission filtering cavity and a tenth emission filtering cavity, and between an eighth emission filtering cavity and a tenth emission filtering cavity of the first emission filtering branch; the first flying bar comprises a first coupling part, a second coupling part and a first connecting part, and two ends of the first connecting part are respectively connected with the first coupling part and the second coupling part;

a first metal coupling rib is arranged between a first emission filtering cavity and a second emission filtering cavity of the first emission filtering branch circuit;

each emission filter cavity of the first emission filter branch is provided with a first mounting column, a first resonance rod and a first tuning rod; the first resonance rod comprises a first U-shaped side wall and a first hollow inner cavity formed by the first U-shaped side wall; the first tuning rod, one end of the first tuning rod is arranged in the first hollow inner cavity; the two ends of the first U-shaped side wall bend and extend in a direction departing from the first hollow inner cavity so as to form first disc-shaped structures at the two ends of the first U-shaped side wall, and the first disc-shaped structures are arranged in parallel with the bottom of the first U-shaped side wall; the first U-shaped side wall is fixed to the first mounting post.

5. The filter of claim 3, wherein the eight transmit filter cavities of the second transmit filter branch are divided into two columns arranged along the second direction;

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

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

6. The filter of claim 5, wherein eight transmit filter cavities of the second transmit filter branch are window-coupled in sequence;

second flying rods are respectively arranged between a third emission filtering cavity and a fifth emission filtering cavity, between the fifth emission filtering cavity and an eighth emission filtering cavity and between a sixth emission filtering cavity and the eighth emission filtering cavity of the second emission filtering branch circuit; the second flying bar comprises a third coupling part, a fourth coupling part and a second connecting part, and two ends of the second connecting part are respectively connected with the third coupling part and the fourth coupling part;

each emission filter cavity of the second emission filter branch is provided with a second mounting column, a second resonance rod and a second tuning rod; the second resonance rod comprises a second U-shaped side wall and a second hollow inner cavity formed by the second U-shaped side wall; the second tuning rod, one end of the second tuning rod is arranged in the second hollow inner cavity; the two ends of the second U-shaped side wall bend and extend in the direction departing from the second hollow inner cavity so as to form second disc-shaped structures at the two ends of the second U-shaped side wall, and the second disc-shaped structures are arranged in parallel with the bottom of the second U-shaped side wall; the second U-shaped side wall is fixed to the second mounting post.

7. The filter of claim 3,

the first receiving filter branch is divided into two rows arranged along the second direction;

the second receiving filter cavity, the fifth receiving filter cavity, the sixth receiving filter cavity, the eighth receiving filter cavity and the ninth receiving filter cavity of the first receiving filter branch are in a row and are sequentially arranged along the first direction;

the first receiving filter cavities of the first receiving filter branch are in a row, and the included angle formed by the straight line formed by connecting the first receiving filter cavities of the first receiving filter branch with the second receiving filter cavities of the first receiving filter branch, the fifth receiving filter cavities of the first receiving filter branch, the sixth receiving filter cavities of the first receiving filter branch, the eighth receiving filter cavities of the first receiving filter branch and the ninth receiving filter cavities of the first receiving filter branch is an acute angle;

the third receiving filter cavity, the fourth receiving filter cavity and the seventh receiving filter cavity of the first receiving filter branch are in a row and are sequentially arranged along the first direction.

8. The filter of claim 7,

nine receiving filter cavities of the first receiving filter branch are sequentially window-coupled;

metal coupling ribs are respectively arranged between the second receiving filter cavity and the fourth receiving filter cavity, between the second receiving filter cavity and the fifth receiving filter cavity, and between the sixth receiving filter cavity and the eighth receiving filter cavity of the first receiving filter branch circuit;

second metal coupling ribs are respectively arranged between a first receiving filter cavity and a second receiving filter cavity, between the second receiving filter cavity and a fourth receiving filter cavity, between the fourth receiving filter cavity and a fifth receiving filter cavity, between the fifth receiving filter cavity and a sixth receiving filter cavity, between the sixth receiving filter cavity and a seventh receiving filter cavity, between the sixth receiving filter cavity and an eighth receiving filter cavity, and between the eighth receiving filter cavity and a ninth receiving filter cavity of the first receiving filter branch;

each receiving filter cavity of the first receiving filter branch is provided with a third mounting column, a third resonance rod and a third tuning rod; the third resonant rod comprises a third U-shaped side wall and a third hollow inner cavity formed by the third U-shaped side wall; one end of the third tuning rod is arranged in the third hollow inner cavity; the two ends of the third U-shaped side wall bend and extend in the direction departing from the third hollow inner cavity, so that third disc-shaped structures are formed at the two ends of the third U-shaped side wall and are arranged in parallel with the bottom of the third U-shaped side wall; the third U-shaped side wall is fixed to the third mounting post.

9. The filter of claim 3,

the second receiving filter branch is divided into three columns arranged along the second direction;

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

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

the seventh receiving filter cavities of the second receiving filter branch are arranged in a row in the first direction in sequence, and the seventh receiving filter cavities, the fourth receiving filter cavities and the third receiving filter cavities are arranged in a straight line;

third flying rods are respectively arranged between the first receiving filter cavity and the third receiving filter cavity, between the fourth receiving filter cavity and the sixth receiving filter cavity and between the fourth receiving filter cavity and the seventh receiving filter cavity of the second receiving filter branch circuit; the third flying bar comprises a fifth coupling part, a sixth coupling part and a third connecting part, and two ends of the third connecting part are respectively connected with the fifth coupling part and the sixth coupling part;

seven receiving filter cavities of the second receiving filter branch are sequentially window-coupled;

third metal coupling ribs are respectively arranged between the first receiving filter cavity and the second receiving filter cavity, between the second receiving filter cavity and the third receiving filter cavity, and between the fourth receiving filter cavity and the fifth receiving filter cavity of the second receiving filter branch circuit;

each receiving filter cavity of the second receiving filter branch is provided with a fourth mounting column, a fourth resonance rod and a fourth tuning rod; the fourth resonant rod comprises a fourth U-shaped side wall and a fourth hollow inner cavity formed by the fourth U-shaped side wall; one end of the fourth tuning rod is arranged in the fourth hollow inner cavity;

the two ends of the fourth U-shaped side wall bend and extend in the direction departing from the fourth hollow inner cavity so as to form fourth disc-shaped structures at the two ends of the fourth U-shaped side wall, and the fourth disc-shaped structures are arranged in parallel with the bottom of the fourth U-shaped side wall; the fourth U-shaped side wall is fixed to the fourth mounting post.

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