CN212323176U - Filter and communication equipment - Google Patents

Abstract

The application discloses a filter and communication equipment. The filter includes: a housing; the transmitting and filtering branch is arranged on the shell and consists of eight transmitting and filtering cavities which are sequentially coupled; capacitive cross coupling is respectively carried out 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 emission filtering branch circuit; wherein, the bandwidth range of the emission filtering branch is 2110MHz-2170 MHz; the receiving filter branch is arranged on the shell and consists of seven receiving filter cavities which are sequentially coupled; capacitive cross coupling is respectively carried out between a first receiving filter cavity and a third receiving filter cavity, between a fourth receiving filter cavity and a sixth receiving filter cavity and between the fourth receiving filter cavity and a seventh receiving filter cavity of the receiving filter branch circuit; the bandwidth of the receiving filtering branch is in the range of 1920MHz-1980 MHz. 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 on signals outside the resonant frequencies, so that the function of selecting microwave transmission signals is realized; the cavity filter has the advantages of reliable structure, wide filtering frequency band, parasitic pass band far away from a channel, high Q value, stable electrical property, good heat dissipation performance and the like.

The inventor of the application finds that the 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 transmitting and filtering branch is arranged on the shell and consists of eight transmitting and filtering cavities which are sequentially coupled; capacitive cross coupling is respectively carried out 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 emission filtering branch circuit; wherein, the bandwidth range of the emission filtering branch is 2110MHz-2170 MHz; the receiving filter branch is arranged on the shell and consists of seven receiving filter cavities which are sequentially coupled; capacitive cross coupling is respectively carried out between a first receiving filter cavity and a third receiving filter cavity, between a fourth receiving filter cavity and a sixth receiving filter cavity and between the fourth receiving filter cavity and a seventh receiving filter cavity of the receiving filter branch circuit; the bandwidth of the receiving filtering branch is in the range of 1920MHz-1980 MHz.

Optionally, the eight emission filter cavities of the emission filter branch are divided into two rows arranged along a second direction, and the second direction is perpendicular to the first direction; a first emission filtering cavity, a second emission filtering cavity, a third emission filtering cavity, a fifth emission filtering cavity and an eighth emission filtering cavity of the emission filtering branch are in a row and are sequentially arranged along a first direction; the fourth emission filtering cavity, the sixth emission filtering cavity and the seventh emission filtering cavity of the emission filtering branch are in a row and are sequentially arranged along the first direction. The eight emission filter cavities are divided into two columns which are sequentially arranged along the second direction, and the eight emission filter cavities are regularly arranged, so that the size of the emission filter branch is reduced, and the size of the filter is further reduced.

Optionally, eight emission filtering cavities of the emission filtering branch are sequentially window-coupled; first 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 emission filtering branch circuit; 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 connected with the first coupling part and the second coupling part respectively. Capacitive cross coupling can be achieved by the first fly rod, and the first fly rod can be made simple in structure for processing and manufacturing.

Optionally, each emission filter cavity is provided with a first mounting post, 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; 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 the 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. The cost of the filter is reduced by pure window coupling between two adjacent filter cavities on the coupling path of the transmitting filter branch; and the first resonant rod may be secured to the housing by a first mounting post, and the resonant frequency of the first resonant cavity may be adjusted by adjusting the depth of the first tuning rod within the first hollow cavity.

Optionally, the receiving filter branches are 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 receiving filter branch are in a row and are sequentially arranged along a first direction; the second receiving filter cavity, the fourth receiving filter cavity and the sixth receiving filter cavity of the receiving filter branch are in a row and are sequentially arranged along the first direction; the seventh receiving filter cavities of the receiving filter branch are arranged in sequence in the first direction, and the seventh receiving filter cavities, the fourth receiving filter cavities and the third receiving filter cavities are arranged in a straight line. The receiving filter branch is divided into three rows which are sequentially arranged along the second direction, and seven receiving filter cavities are regularly arranged, so that the size of the receiving filter branch is reduced, and the size of the filter is further reduced.

Optionally, second 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 receiving filter branch; 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. Capacitive cross coupling can be achieved by the second fly rod, and the second fly rod can make its structure simple for processing and manufacturing.

Optionally, seven receiving filter cavities of the receiving filter branch are sequentially window-coupled, and 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 third receiving filter cavity, and between a fourth receiving filter cavity and a fifth receiving filter cavity of the receiving filter branch. The filter cost is reduced by pure window coupling between two adjacent filter cavities on the receiving filter branch coupling path, and the coupling strength 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 on the receiving filter branch coupling path can be improved through the metal coupling ribs, so that the energy loss is reduced, and the energy transmission quality is improved.

Optionally, each receiving filter cavity is provided with a second mounting post, 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; 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. The second resonant rod may be secured to the housing by a second mounting post, and the resonant frequency of the second resonant cavity may be adjusted by adjusting the depth of the second tuning rod within the second hollow cavity.

Optionally, the first port is connected to the eighth transmit filter cavity of the transmit filter branch and the seventh receive filter cavity of the receive filter branch;

the second port is connected with the first emission filtering cavity of the emission filtering branch circuit;

and the third port is connected with the first receiving filter cavity of the receiving filter branch circuit.

The transmitting filtering branch and the receiving filtering branch share the first port, so that the cost can be saved, and the size of the filter can be reduced.

In order to solve the above technical problem, the present application adopts another technical solution: a communication device is provided. The communication equipment comprises an antenna and a radio frequency unit connected with the antenna, wherein the radio frequency unit comprises the filter and is used for filtering radio frequency signals.

The beneficial effect of this application is: different from the prior art, capacitive cross coupling is respectively performed between the third emission filter cavity and the fifth emission filter cavity, between the fifth emission filter cavity and the eighth emission filter cavity, and between the sixth emission filter cavity and the eighth emission filter cavity of the emission filter branch circuit in the embodiment of the present application, so that high-end rejection of a bandwidth of the emission filter branch circuit can be well controlled, so as to obtain better high-end rejection of the bandwidth, and low-end rejection of a bandwidth of the emission filter branch circuit can be well controlled, so as to obtain better low-end rejection of the bandwidth; capacitive cross coupling is carried out between a first receiving filter cavity and a third receiving filter cavity, between a fourth receiving filter cavity and a sixth receiving filter cavity and between a fourth receiving filter cavity and a seventh receiving filter cavity of the receiving filter branch, so that high-end rejection of the bandwidth of the receiving filter branch can be well controlled, good high-end rejection of the bandwidth can be obtained, low-end rejection of the bandwidth of the receiving filter branch can be well controlled, good low-end rejection of the bandwidth can be obtained, and therefore the stop band rejection performance of the filter can be improved; in addition, the bandwidth range of the transmitting and filtering branch is 2110MHz-2170MHz, and the bandwidth of the transmitting and filtering branch can be accurately controlled; the bandwidth of the receiving filtering branch ranges from 1920MHz to 1980MHz, and the bandwidth of the receiving filtering branch can be accurately controlled.

Drawings

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings needed to be used in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings without creative efforts.

FIG. 1 is a schematic diagram of the structure of the transmitting filter branch of the filter of the present application;

FIG. 2 is a schematic diagram of the topology of the 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 support clamping seat in the transmitting filter branch of the embodiment of FIG. 1;

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

FIG. 6 is a schematic diagram of a simulation structure of the transmitting filter branch in the embodiment of FIG. 1;

FIG. 7 is a block diagram of a receiving filter branch of the filter of the present application;

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

FIG. 9 is a schematic diagram of an equivalent circuit structure of the receiving filter branch of the embodiment in FIG. 7;

FIG. 10 is a diagram illustrating a simulation structure of the receiving filter branch in the embodiment of FIG. 7;

fig. 11 is a schematic diagram of an equivalent circuit structure in which a transmitting filter branch and a receiving filter branch are combined to form a filter;

fig. 12 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 transmitting filter branch of the filter of the present application, and fig. 2 is a schematic structural diagram of the transmitting filter branch of the embodiment of fig. 1. The filter 10 of the present embodiment includes a housing 11 and a transmitting filter branch 12. And the transmitting and filtering branch 12 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 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, and an eighth emission filter cavity A8; capacitive cross coupling is respectively formed between the third emission filter cavity A3 and the fifth emission filter cavity A5, between the fifth emission filter cavity A5 and the eighth emission filter cavity A8, and between the sixth emission filter cavity A6 and the eighth emission filter cavity A8; wherein, the bandwidth of the transmitting and filtering branch circuit 12 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 A3 and the fifth emission filter cavity a5, between the fifth emission filter cavity a5 and the eighth emission filter cavity A8, and between the sixth emission filter cavity a6 and the eighth emission filter cavity A8 of the emission filter branch 12, so that high-end rejection of the bandwidth of the 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 emission filter branch can be well controlled to obtain better low-end rejection of the bandwidth, and therefore, the stop-band rejection performance of the filter 10 can be improved; in addition, the bandwidth of the transmitting and filtering branch 12 ranges from 2110MHz to 2170MHz, and the bandwidth of the transmitting and filtering branch 12 can be precisely controlled.

Optionally, as shown in fig. 1, the eight emission filter cavities of the 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 third emission filter cavity A3, the fifth emission filter cavity a5 and the eighth emission filter cavity A8 of the emission filter branch 12 are in a row and are sequentially arranged along a first direction x; the fourth emission filter cavity a4, the sixth emission filter cavity a6 and the seventh emission filter cavity a7 of the emission filter branch 12 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 emission filter branch 12, and further reduce the volume of the filter 10.

Optionally, as shown in fig. 1, eight emission filter cavities of the emission filter branch 12 are sequentially window-coupled, that is, a first emission filter cavity a1 is window-coupled to a second emission filter cavity a2, a second emission filter cavity a2 is window-coupled to a third emission filter cavity A3, a third emission filter cavity A3 is window-coupled to a fourth emission filter cavity a4, a fourth emission filter cavity a4 is window-coupled to a fifth emission filter cavity a5, a fifth emission filter cavity a5 is window-coupled to a sixth emission filter cavity A6, a sixth emission filter cavity A6 is window-coupled to a seventh emission filter cavity a7, and a seventh emission filter cavity a7 is window-coupled to an eighth emission filter cavity A8.

Therefore, the two adjacent filter cavities on the coupling path of the 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 emission filter cavity is provided with a first mounting post 40, a first resonant 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. In this embodiment, the first resonant rod 20, the first hollow cavity 220 and the first tuning rod 30 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 also be an M8 or M4 screw rod, and the like, and is made of copper or silver.

The eight emission filter cavities of the 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 21mm, e.g., 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 the transmitting filter branch of the embodiment of fig. 1. First flying rods 60 are respectively arranged between the third emission filter cavity A3 and the fifth emission filter cavity A5, between the fifth emission filter cavity A5 and the eighth emission filter cavity A8, and between the sixth emission filter cavity A6 and the eighth emission filter cavity A8 of the emission filter branch 12, so that the third emission filter cavity A3 and the fifth emission filter cavity A5, between the fifth emission filter cavity A5 and the eighth emission filter cavity A8, and between the sixth emission filter cavity A6 and the eighth emission filter cavity A8 are respectively capacitively cross-coupled. 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 third emission filter cavity A3 to form a coupling capacitance therebetween, and the second coupling part 620 is coupled with the first resonance rod 20 in the fifth emission filter cavity a5 to form a coupling capacitance therebetween.

Similarly, the first flying rod 60 is respectively arranged between the fifth emission filter cavity a5 and the eighth emission filter cavity A8, and between the sixth emission filter cavity a6 and the eighth emission filter cavity A8 of the emission filter branch 12, and the first flying rod 60 is arranged between the third emission filter cavity A3 and the fifth emission filter cavity a5, which is not described herein again.

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. For example, metal flying rods are respectively arranged between the fifth emission filter cavity a5 and the eighth emission filter cavity A8 and/or between the sixth emission filter cavity a6 and the eighth emission filter cavity A8 of the emission filter branch 12, each metal flying rod comprises a screw and a metal sheet connected with the screw, the screw is used for fixing the metal sheet on the bottom platform of the fifth emission filter cavity a5, the sixth emission filter cavity a6 and the eighth emission filter cavity A8, the diameter of the bottom platform can be phi 5mm, and therefore, the capacitive cross coupling between the fifth emission filter cavity a5 and the eighth emission filter cavity A8 and between the sixth emission filter cavity a6 and the eighth emission filter cavity A8 of the filter branch 12 can be realized through the metal flying rods.

It can be seen that, capacitive cross coupling is respectively performed between the third emission filter cavity A3 and the fifth emission filter cavity a5, between the fifth emission filter cavity a5 and the eighth emission filter cavity A8, and between the sixth emission filter cavity a6 and the eighth emission filter cavity A8 of the emission filter branch 12, so that three capacitive coupling zeros can be realized, and zero suppression is realized.

As shown in FIG. 2, specifically, the third emission filter cavity A3 and the fifth emission filter cavity A5 are capacitively cross-coupled to form a capacitive couplingCross coupling C₁The fifth emission filter cavity A5 and the eighth emission filter cavity A8 are capacitively cross-coupled to form a capacitive cross-coupling C₂The sixth emission filter cavity A6 and the eighth emission filter cavity A8 are capacitively cross-coupled to form a capacitive cross-coupling C₃To form the three cross-coupled zeros of the 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 transmitting filter branch 12 is shown in fig. 5, and 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 eight emission filter cavities of the 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 eighth emission filter cavity A8 and the output port, so as to implement impedance matching.

The bandwidth range of the transmitting filtering branch 12 of the filter 10 of the present embodiment is: 2110MHz to 2170 MHz. Specifically, the coupling bandwidth between the first port and the first emission filter cavity a1 ranges from 62Mhz to 73 Mhz; the coupling bandwidth between the first emission filter cavity a1 and the second emission filter cavity a2 ranges from 49Mhz to 59 Mhz; the coupling bandwidth between the second emission filter cavity a2 and the third emission filter cavity A3 ranges from 34Mhz-42 Mhz; the coupling bandwidth between the third emission filter cavity A3 and the fourth emission filter cavity a4 ranges from 31Mhz to 38 Mhz; the coupling bandwidth between the third emission filter cavity A3 and the fifth emission filter cavity a5 ranges from (-6) Mhz- (-1.6) Mhz; the coupling bandwidth between the fourth emission filter cavity a4 and the fifth emission filter cavity a5 ranges from 30Mhz to 38 Mhz; the coupling bandwidth between the fifth emission filter cavity a5 and the sixth emission filter cavity a6 ranges from 23Mhz to 30 Mhz; the coupling bandwidth between the sixth emission filter cavity a6 and the seventh emission filter cavity a7 ranges from 49Mhz to 59 Mhz; the coupling bandwidth between the sixth emission filter cavity a6 and the eighth emission filter cavity A8 ranges from (-2.4) Mhz- (-2) Mhz; the coupling bandwidth between the seventh emission filter cavity a7 and the eighth emission filter cavity A8 ranges from 42Mhz to 51 Mhz; the coupling bandwidth between the eighth emission filter cavity A8 and the second port is in the range of 62Mhz-73Mhz, which can meet the design requirement.

Therefore, the resonant frequencies of the first emission filter cavity a1 to the eighth emission filter cavity A8 of the filter 10 are sequentially located in the following ranges: 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.

Further, the simulation result of the transmitting filter branch 12 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, there are a low-end coupling zero point a and a high-end coupling zero point b. The transmit filter branch 12 has three capacitive cross-coupling zeros, but since the same rf parameters of the zeros will result in some simulation points being the same, only two cross-coupling zeros are shown in the simulation. The inhibition of the transmitting and filtering branch 12 at the frequency point 2.104GHz (m13) is-20.968 dB, and the inhibition of the transmitting and filtering branch 12 at the frequency point 2.176GHz (m14) is-20.672 dB. Therefore, the design requirement of out-of-band rejection of the transmit filter branch 12 can be met.

Referring to fig. 7 and 8, fig. 7 is a schematic diagram of a receiving filter branch of a filter according to the present application, and fig. 8 is a schematic diagram of a topology structure of the receiving filter branch of the embodiment of fig. 7. The filter 10 further includes a receiving filter branch 13 disposed on the housing 11 and composed of seven receiving filter cavities coupled in sequence.

Specifically, the seven receiving filter cavities of the receiving filter branch 13 include a first receiving filter cavity B1, a second receiving filter cavity B2, a third receiving filter cavity B3, a fourth receiving filter cavity B4, a fifth receiving filter cavity B5, a sixth receiving filter cavity B6 and a seventh receiving filter cavity B7.

Capacitive cross coupling is respectively formed between the first receiving filter cavity B1 and the third receiving filter cavity B3, between the fourth receiving filter cavity B4 and the sixth receiving filter cavity B6, and between the fourth receiving filter cavity B4 and the seventh receiving filter cavity B7 of the receiving filter branch 13, wherein the bandwidth of the receiving filter branch 13 is 1920MHz-1980 MHz.

Specifically, as shown in fig. 8, the first receiving filter cavity B1 and the third receiving filter cavity B3 of the receiving filter branch 13 are capacitively cross-coupled to form a capacitive cross-coupling zero C₄And the fourth receiving filter cavity B4 and the sixth receiving filter cavity B6 are capacitively cross-coupled to form a capacitive cross-coupling zero point C₅And the fourth receiving filter cavity B4 and the seventh receiving filter cavity B7 are capacitively cross-coupled to form a capacitive cross-coupling zero point C₆To form three capacitive cross-coupling zeros of the receive filter branch 13.

It can be seen that, capacitive cross coupling is respectively formed between the first receiving filter cavity B1 and the third receiving filter cavity B3, between the fourth receiving filter cavity B4 and the sixth receiving filter cavity B6, and between the fourth receiving filter cavity B4 and the seventh receiving filter cavity B7 of the receiving filter branch 13, so as to form three capacitive cross coupling zeros, which can well control the high-end rejection of the bandwidth of the receiving filter branch to obtain better high-end rejection of the bandwidth, and can well control the low-end rejection of the bandwidth of the receiving filter branch to obtain better low-end rejection of the bandwidth, thereby improving the stop-band rejection performance of the filter; in addition, the bandwidth range of the transmitting and filtering branch is 2110MHz-2170MHz, and the bandwidth of the transmitting and filtering branch can be accurately controlled; the bandwidth of the receiving filtering branch ranges from 1920MHz to 1980MHz, and the bandwidth of the receiving filtering branch can be accurately controlled.

Optionally, the receiving filter branch 13 is divided into three columns arranged along the second direction y; the second receiving filter cavity B2, the fourth receiving filter cavity B4 and the sixth receiving filter cavity B6 of the receiving filter branch 13 are in a row and are sequentially arranged along the first direction x; the seventh receiving filter cavities B7 of the receiving filter branch 13 are arranged in a row in the first direction x, and the seventh receiving filter cavity B7, the fourth receiving filter cavity B4 and the third receiving filter cavity B3 are arranged in a straight line.

As can be seen, the receiving filter branch 13 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 receiving filter branch 13, and further reduce the volume of the filter 10.

Optionally, seven receiving filter cavities of the receiving filter branch 13 are sequentially window-coupled, that is, a first receiving filter cavity B1 and a second receiving filter cavity B2 are window-coupled, a second receiving filter cavity B2 and a third receiving filter cavity B3 are window-coupled, a third receiving filter cavity B3 and a fourth receiving filter cavity B4 are window-coupled, a fourth receiving filter cavity B4 and a fifth receiving filter cavity B5 are window-coupled, a fifth receiving filter cavity B5 and a sixth receiving filter cavity B6 are window-coupled, and a sixth receiving filter cavity B6 and a seventh receiving filter cavity B7 are window-coupled.

The cost of the filter 10 is reduced by pure window coupling between two adjacent filter cavities on the coupling path of the receiving filter branch 13.

In addition, metal coupling ribs 81 are respectively arranged between the first receiving filter cavity B1 and the second receiving filter cavity B2, between the second receiving filter cavity B2 and the third receiving filter cavity B3, and between the fourth receiving filter cavity B4 and the fifth receiving filter cavity B5 of the receiving filter branch 13.

Therefore, the coupling strength between the first receiving filter cavity B1 and the second receiving filter cavity B2, between the second receiving filter cavity B2 and the third receiving filter cavity B3, and between the fourth receiving filter cavity B4 and the fifth receiving filter cavity B5 on the coupling path of the receiving filter branch 13 can be improved by the metal coupling rib 81, so that the loss of energy is reduced, and the quality of energy transmission is improved.

Each receiving filter cavity is provided with a second mounting post, a second resonant 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 schematic structural diagram of the combined structure of the second tuning rod 31, the second resonant rod 21 and the second mounting post of the receiving filtering branch 13 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 transmitting 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 the second resonant cavity can be adjusted by adjusting the depth of the second tuning rod 31 within the second hollow cavity.

Seven receiving filter cavities of the receiving filter branch circuit 13 are the same in size, so that the production is convenient, and the cost is saved. The radius of the seven receiving filter cavities may be less than 21mm, e.g. 20mm, 19mm, 18mm, etc.

Second flying rods are respectively arranged between the first receiving filter cavity B1 and the third receiving filter cavity B3, between the fourth receiving filter cavity B4 and the sixth receiving filter cavity B6, and between the fourth receiving filter cavity B4 and the seventh receiving filter cavity B7 of the receiving 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 structure 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 receiving filtering branch 13 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 transmitting filtering branch 12, as shown in fig. 4, and is not repeated here.

The equivalent circuit of the receiving filtering branch 13 is shown in fig. 9, with an impedance Z3 at the input port of about 50 ohms and an impedance Z4 at the output port of about 50 ohms; in order to ensure that electromagnetic signals are transmitted between the seven receiving filter cavities of the receiving filter branch 13, impedance adjusters ZV2 are respectively arranged between the input port and the first receiving filter cavity B1, between adjacent filter cavities on the coupling path, between non-cascaded filter cavities forming cross coupling, and between the seventh receiving filter cavity B7 and the output port, so as to realize impedance matching.

The bandwidth range of the receiving filtering branch 13 of the filter 10 of the present embodiment is: 1920MHz-1980 MHz. Specifically, the coupling bandwidth between the first port and the first receiving filter cavity B1 ranges from 472Mhz to 529 Mhz; the coupling bandwidth between the first receiving filter cavity B1 and the second receiving filter cavity B2 ranges from 169Mhz-192 Mhz; the coupling bandwidth between the second receiving filter cavity B2 and the third receiving filter cavity B3 ranges from 47Mhz to 57 Mhz; the coupling bandwidth between the second receiving filter cavity B2 and the fourth receiving filter cavity B4 ranges from (-16) Mhz- (-11) Mhz; the coupling bandwidth between the third receiving filter cavity B3 and the fourth receiving filter cavity B4 ranges from 35Mhz to 43 Mhz; the coupling bandwidth between the fourth receiving filter cavity B4 and the fifth receiving filter cavity B5 ranges from 34Mhz-42 Mhz; the coupling bandwidth between the fifth receiving filter cavity B5 and the sixth receiving filter cavity B6 ranges from 33Mhz to 41 Mhz; the coupling bandwidth between the fifth receiving filter cavity B5 and the eighth receiving filter cavity B8 ranges from (-9.6) Mhz- (-4.8) Mhz; the coupling bandwidth between the sixth receiving filter cavity B6 and the seventh receiving filter cavity B7 ranges from 41Mhz to 49 Mhz; the coupling bandwidth between the sixth receiving filter cavity B6 and the eighth receiving filter cavity B8 ranges from 3.9Mhz to 8.5 Mhz; the coupling bandwidth between the seventh receiving filter cavity B7 and the eighth receiving filter cavity B8 ranges from 53Mhz to 63 Mhz; the coupling bandwidth between the eighth receiving filter cavity B8 and the second port is in the range of 68Mhz-80Mhz, which can meet the design requirement.

Therefore, the resonant frequencies of the first receiving filter cavity B1 through the eighth receiving filter cavity B8 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 receiving filter branch 13 is shown in fig. 10, and it can be seen from fig. 10 that through experimental tests, as shown by the frequency band curve S2, there are two low-end coupling zero points c and d and one high-end coupling zero point e. The suppression of the receiving filtering branch 13 at the frequency point 1.884GHz (m11) is-83.924 dB, and the suppression of the receiving filtering branch 13 at the frequency point 2.004GHz (m12) is-48.837 dB, so that the receiving filtering branch 13 can meet the design requirement of out-of-band suppression.

Referring to fig. 11, fig. 11 is a schematic diagram of an equivalent circuit structure of a filter formed by combining a transmitting filter branch and a receiving filter branch. The filter 10 includes a transmit filter branch 12, a receive filter branch 13, a first port, a second port, and a third port.

Optionally, the first port is respectively connected with the eighth transmitting filter cavity A8 of the transmitting filter branch 12 and the seventh receiving filter cavity B7 of the receiving filter branch 13; the second port is connected with the first emission filter cavity a1 of the emission filter branch circuit 12; the third port is connected to the first receiving filter cavity B1 of the receiving filter branch 13. Therefore, the transmitting filter branch 12 and the receiving filter branch 13 share the first port, which can save cost and reduce the size of the filter 10.

The filter 10 is a microwave filter applied to a 5G mobile communication system, the working frequency band of a transmitting filtering branch is 2110MHz-2170MHz, the working frequency band of a receiving filtering branch is 1920MHz-1980MHz, and the microwave filter has the characteristics of strong anti-interference capability, small integral volume 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 transmitting and filtering branch of the filter 10 is designed by combining 8-order resonant cavities, the receiving and filtering branch of the filter 10 is designed by combining 7-order resonant cavities, and a coupling zero structure is introduced, so that the high-frequency-resistant filter has high anti-interference capacity and can ensure that a communication system is not 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. 12, fig. 12 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 (10)

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

a housing;

the transmitting and filtering branch is arranged on the shell and consists of eight transmitting and filtering cavities which are sequentially coupled; capacitive cross coupling is respectively carried out 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 emission filtering branch circuit; wherein the bandwidth range of the transmitting and filtering branch is 2110MHz-2170 MHz;

the receiving filter branch is arranged on the shell and consists of seven receiving filter cavities which are sequentially coupled; capacitive cross coupling is respectively formed between a first receiving filter cavity and a third receiving filter cavity, between a fourth receiving filter cavity and a sixth receiving filter cavity, and between the fourth receiving filter cavity and a seventh receiving filter cavity of the receiving filter branch circuit; wherein the bandwidth of the receiving filtering branch is in the range of 1920MHz-1980 MHz.

2. The filter according to claim 1, wherein the eight transmitting filter cavities of the transmitting filter branch are divided into two rows arranged along a second direction, and the second direction is perpendicular to the first 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 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 emission filtering branch are in a row and are sequentially arranged along the first direction.

3. The filter of claim 2, wherein eight transmit filter cavities of the transmit filter branch are sequentially window-coupled;

first 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 emission filtering branch circuit; 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.

4. The filter of claim 3,

each emission filter cavity 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 4,

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

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

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

6. The filter of claim 5,

second 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 receiving filter 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.

7. The filter of claim 6, wherein seven receiving filter cavities of the receiving filter branch are window-sequentially coupled;

and metal coupling ribs are respectively arranged between the first receiving filter cavity and the second receiving filter cavity of the receiving filter branch, 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.

8. The filter of claim 7,

each receiving filter cavity 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.

9. The filter of claim 8, further comprising:

the first port is connected with the eighth transmitting filter cavity of the transmitting filter branch circuit and the seventh receiving filter cavity of the receiving filter branch circuit;

the second port is connected with the first emission filtering cavity of the emission filtering branch circuit;

and the third port is connected with the first receiving filter cavity of the receiving filter branch circuit.

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.

Images