CN216214003U - Filter and communication device - Google Patents

Abstract

The application discloses wave filter and communication equipment, the wave filter includes: the filter comprises a shell, a first filter branch and a second filter branch, wherein the first filter branch is arranged on the shell and consists of eight filter cavities which are sequentially coupled, and the eight filter cavities of the first filter branch form three capacitive cross-coupling zero points and one inductive cross-coupling zero point; the second filtering branch is arranged on the shell and consists of nine filtering cavities which are sequentially coupled, and the nine filtering cavities of the second filtering branch form four capacitive cross-coupling zero points and one inductive cross-coupling zero point; wherein the first filtering branch and the second filtering branch share an output end of the filter. This application can strengthen the stop band rejection performance of wave filter through above mode.

Description

Filter and communication device

Technical Field

The application relates to the technical field of communication, in particular to a filter and communication equipment.

Background

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

A plurality of filter cavities in the existing cavity filter are arranged in a complex and irregular mode, the size of the filter is increased, and the stop band rejection performance of the cavity filter is poor.

SUMMERY OF THE UTILITY MODEL

The application aims to provide a filter and a communication device, and the stop band suppression performance of the filter is enhanced.

The application discloses a filter, the filter includes: the filter comprises a shell, a first filter branch and a second filter branch, wherein the first filter branch is arranged on the shell and consists of eight filter cavities which are sequentially coupled, and the eight filter cavities of the first filter branch form three capacitive cross-coupling zero points and one inductive cross-coupling zero point; the second filtering branch is arranged on the shell and consists of nine filtering cavities which are sequentially coupled, and the nine filtering cavities of the second filtering branch form four capacitive cross-coupling zero points and one inductive cross-coupling zero point; wherein the first filtering branch and the second filtering branch share an output end of the filter.

Optionally, the filter further includes: the output port is connected with the eighth filter cavity of the first filter branch and the ninth filter cavity of the second filter branch; the first input end is connected with a first filter cavity of the first filter branch circuit; the second input end is connected with the first filter cavity of the second filter branch circuit.

Optionally, the housing has a first direction and a second direction perpendicular to the first direction; the eight filter cavities of the first filter branch circuit are divided into three rows arranged along the first direction; the first filtering cavity, the second filtering cavity and the eighth filtering cavity of the first filtering branch are arranged in a row in sequence along the second direction; the third filtering cavity, the sixth filtering cavity and the seventh filtering cavity of the first filtering branch are arranged in a row in sequence along the second direction; the fourth filtering cavity of the first filtering branch and the fifth filtering cavity of the first filtering branch are arranged in a row along the second direction in sequence.

Optionally, the nine filter cavities of the second filter branch are divided into four rows arranged along the first direction; the second filtering cavities and the third filtering cavities of the second filtering branch are arranged in a row and are sequentially arranged along the second direction; the first filtering cavity, the fourth filtering cavity and the fifth filtering cavity of the second filtering branch are in a row and are sequentially arranged along the second direction; the sixth filtering cavities and the seventh filtering cavities of the second filtering branch are arranged in a row and are sequentially arranged along the second direction; the eighth filtering cavity and the ninth filtering cavity of the second filtering branch are arranged in a row and are sequentially arranged along the second direction.

Optionally, capacitive cross-coupling elements are respectively arranged between the first filter cavity and the third filter cavity, between the third filter cavity and the fifth filter cavity, and between the third filter cavity and the sixth filter cavity of the first filter branch; an inductive cross coupling element is arranged between the sixth filtering cavity and the eighth filtering cavity of the first filtering branch circuit; the working frequency band of the first filtering branch is 3700-3800 MHZ.

Optionally, capacitive cross-coupling elements are respectively arranged between the first filter cavity and the fourth filter cavity, between the second filter cavity and the fourth filter cavity, between the sixth filter cavity and the eighth filter cavity, and between the sixth filter cavity and the ninth filter cavity of the second filter branch; an inductive cross coupling element is arranged between a fourth filtering cavity and a sixth filtering cavity of the second filtering branch circuit; the working frequency band of the second filtering branch circuit is 3900-.

Optionally, the capacitive cross-coupling element and the inductive cross-coupling element are both flying rods; flying rods are respectively arranged between the first filtering cavity and the fourth filtering cavity, between the second filtering cavity and the fourth filtering cavity, between the sixth filtering cavity and the eighth filtering cavity and between the sixth filtering cavity and the ninth filtering cavity of the second filtering branch circuit; the flying rod comprises a first coupling part, a second coupling part and a connecting part, wherein two ends of the connecting part are respectively connected with the first coupling part and the second coupling part and used for coupling two adjacent filter cavities; in the first filtering branch and the second filtering branch, two adjacent filtering cavities are provided with windows corresponding to the positions of the flying rods; a supporting clamping seat is arranged in the window, and the flying rod is fixed on the supporting clamping seat.

Optionally, each of the filter cavities of the first filter branch and the second filter branch is provided with a resonant rod and a tuning rod; the resonance rod comprises a side wall and a hollow inner cavity formed by the side wall; one end of the tuning rod is arranged in the hollow inner cavity; the side wall is close to one side of resonance pole is provided with the turn-ups, and the resonance pole is made for the invar steel material.

Optionally, eight filter cavities of the first filter branch are sequentially window-coupled; and metal coupling ribs are arranged between the first filtering cavity and the second filtering cavity, between the second filtering cavity and the third filtering cavity, between the third filtering cavity and the fourth filtering cavity, between the fourth filtering cavity and the fifth filtering cavity, between the fifth filtering cavity and the sixth filtering cavity, between the seventh filtering cavity and the eighth filtering cavity, and between the eighth filtering cavity and the ninth filtering cavity of the second filtering branch.

The application also discloses a communication device, the communication device include the antenna and with the radio frequency unit that the antenna is connected, the radio frequency unit includes foretell the wave filter for carry out the filtering to radio frequency signal.

According to the filter, the filter is designed into two filtering branches, eight-order four zero points are formed through eight filtering cavities of one filtering branch, nine-order five zero points are formed through nine filtering cavities of the other filtering branch, two inductive cross-coupling zero points are respectively formed in the first filtering branch and the second filtering branch, high-end suppression of the bandwidth of the filtering branches can be well controlled, and good high-end suppression of the bandwidth is obtained; three capacitive cross coupling zero points formed in the first filtering branch circuit and four capacitive cross coupling zero points formed in the second filtering branch circuit are introduced into the transmission zero point structure, so that the high anti-interference capability is realized, and the communication system is ensured not to be interfered by stray signals.

Drawings

The accompanying drawings, which are included to provide a further understanding of the embodiments of the application, are incorporated in and constitute a part of this specification, illustrate embodiments of the application and together with the description serve to explain the principles of the application. It is obvious that the drawings in the following description are only some embodiments of the application, and that for a person skilled in the art, other drawings can be derived from them without inventive effort. In the drawings:

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

fig. 2 is a schematic diagram of a topology of a first filtering branch according to an embodiment of the present application;

fig. 3 is a schematic diagram of a topology of a second filtering branch according to an embodiment of the present application;

fig. 4 is a schematic diagram of a first filtering branch and a second filtering branch combining circuit according to an embodiment of the present application;

FIG. 5 is a waveform diagram illustrating a parameter response of a first filtering branch and a second filtering branch combined circuit according to an embodiment of the present application;

fig. 6 is a schematic diagram of a partial filter cavity of a filter according to an embodiment of the present application:

FIG. 7 is a schematic structural diagram of a filter cavity according to an embodiment of the present disclosure;

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

10, communication equipment; 100. a filter; 200. an antenna; 300. a radio frequency unit; 110. a housing; 120. a first filtering branch; 130. a second filtering branch; 140. an output port; 150. a first input terminal; 160. a second input terminal; d1, first direction; d2, second direction; 170. a flying bar; 171. a first coupling part; 172. a second coupling part; 173. a connecting portion; 180. a window; 181. supporting the card holder; 190. a filter cavity; 191. a resonant rod; 192. A tuning rod; 193. a side wall; 194. a hollow interior cavity; 195. flanging; 196. a metal coupling rib; 400. low pass.

Detailed Description

It is to be understood that the terminology, the specific structural and functional details disclosed herein are for the purpose of describing particular embodiments only, and are representative, but that the present application may be embodied in many alternate forms and should not be construed as limited to only the embodiments set forth herein.

In the description of the present application, the terms "first", "second" are used for descriptive purposes only and are not to be construed as indicating relative importance or as implicitly indicating the number of technical features indicated. Thus, unless otherwise specified, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature; "plurality" means two or more. The terms "comprises" and "comprising," and any variations thereof, are intended to cover a non-exclusive inclusion, such that one or more other features, integers, steps, operations, elements, components, and/or combinations thereof may be present or added.

Further, terms of orientation or positional relationship indicated by "center", "lateral", "upper", "lower", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like, are described based on the orientation or relative positional relationship shown in the drawings, are simply for convenience of description of the present application, and do not indicate that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present application.

Furthermore, unless expressly stated or limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly and may include, for example, fixed connections, removable connections, and integral connections; can be mechanically or electrically connected; either directly or indirectly through intervening media, or through both elements. The specific meaning of the above terms in the present application can be understood by those of ordinary skill in the art as appropriate.

The present application is described in detail below with reference to the figures and alternative embodiments.

Fig. 1 is a schematic structural diagram of a filter according to an embodiment of the present application, and as shown in fig. 1, the present application discloses a filter 100, where the filter 100 includes: a housing 110 having a first direction D1 and a second direction D2 perpendicular to the first direction D1; the first filtering branch 120 is arranged on the housing 110 and consists of eight filtering cavities 190 coupled in sequence, and the eight filtering cavities 190 of the first filtering branch 120 form four capacitive cross-coupling zeros; the second filtering branch 130 is arranged on the housing 110 and consists of nine filtering cavities 190 coupled in sequence, and the nine filtering cavities 190 of the second filtering branch 130 form five capacitive cross-coupling zeros; the first filtering branch 120 and the second filtering branch 130 share an output terminal of the filter 100.

The filter is a communication device for frequency selection and signal suppression, and the filter cavity of the filter mainly plays a role in frequency control, and the filter cavity is required by the communication device which relates to frequency transmission and reception.

According to the filter 100, the filter is designed into two filtering branches, 8-order 4 zero points are formed by eight filtering cavities 190 of one filtering branch, and 9-order 5 zero points are formed by nine filtering cavities 190 of the other filtering branch, wherein two inductive cross-coupling zero points are respectively formed in the first filtering branch 120 and the second filtering branch 130, so that high-end suppression of the bandwidth of the filtering branches can be well controlled, and better high-end suppression of the bandwidth is obtained; three capacitive cross coupling zeros formed in the first filtering branch 120 and four capacitive cross coupling zeros formed in the second filtering branch 130 are introduced into the transmission zero structure, so that the anti-interference capability is strong, and the communication system is ensured not to be interfered by stray signals.

Furthermore, the filter 100 in the present application further includes: an output port 140 connected to the eighth filter cavity A8 of the first filter branch 120 and the ninth filter cavity B9 of the second filter branch 130; a first input terminal 150 connected to the first filter cavity a1 of the first filter branch 120; the second input terminal 160 is connected to the first filter cavity B1 of the second filter branch 130.

Therefore, the first filtering branch 120 and the second filtering branch 130 share the output port 140, which can save cost and reduce the size of the filter 100. The design scheme adopts a double low-pass structure, and can obviously improve the far-end inhibition.

Specifically, as shown in fig. 1, the eight filter cavities 190 of the first filter branch 120 are divided into three columns arranged along the first direction D1; the nine filter cavities 190 of the second filter branch 130 are divided into four columns arranged along the first direction D1; the first filtering cavity a1, the second filtering cavity a2 and the eighth filtering cavity A8 of the first filtering branch 120 are arranged in a row in sequence along the second direction D2; the third filtering cavity A3, the sixth filtering cavity a6 and the seventh filtering cavity a7 of the first filtering branch 120 are arranged in a row in sequence along the second direction D2; the fourth filter cavity a4 and the fifth filter cavity a5 of the first filter branch 120 are arranged in a row in sequence along the second direction D2; the second filtering cavity B2 and the third filtering cavity B3 of the second filtering branch 130 are in a row and are sequentially arranged along the second direction D2; the first filtering cavity B1, the fourth filtering cavity B4 and the fifth filtering cavity B5 of the second filtering branch 130 are in a row and are sequentially arranged along a second direction D2; the sixth filtering cavity B6 and the seventh filtering cavity B7 of the second filtering branch 130 are in a row and are sequentially arranged along the second direction D2; the eighth filter cavity B8 and the ninth filter cavity B9 of the second filter branch 130 are arranged in a row and are sequentially arranged along the second direction D2. In this embodiment, two ends of the passband respectively generate 2 transmission zeros, thereby realizing the strong rejection function of the stop band.

Because this application has adopted two filters branch road to form wave filter 100, the filtering chamber 190 in wave filter 100 is in a great number, consequently has carried out the design of arranging to filtering chamber 190 on two filtering branch roads, specifically arranges as follows:

the 8 filter cavities 190 of the first filter branch 120 are arranged in three rows, the filter cavity 190 connected with the input end of the filter 100 in the first filter branch 120 is taken as a first filter cavity a1, the first filter cavity a1 is taken as a starting point, and a second filter cavity a2 and an eighth filter cavity A8 are sequentially arranged along a second direction D2, wherein the eighth filter cavity A8 is connected with the power amplifier end of the filter 100 and taken as a first row; the third filtering cavity A3, the sixth filtering cavity A6 and the seventh filtering cavity A7 are sequentially arranged along the second direction D2 as a second row, and the fourth filtering cavity A4 and the fifth filtering cavity A5 are sequentially arranged along the second direction D2 as a third row;

9 filter cavities 190 of the second filter branch 130 are divided into four rows to be arranged, the filter cavity 190 connected with the other input end of the filter 100 in the second filter branch 130 is taken as a first filter cavity B1 in the second filter branch 130, the first filter cavity B1, the fourth filter cavity B4 and the fifth filter cavity B5 in the second filter branch 130 are sequentially arranged along the second direction D2 to serve as a second row positioned in the middle, the second filter cavity B2 and the third filter cavity B3 are sequentially arranged along the second direction D2 to serve as a first row, and the sixth filter cavity B6 and the seventh filter cavity B7 are taken as a row and are sequentially arranged along the second direction D2 to serve as a third row; the eighth filter cavity B8 and the ninth filter cavity B9 of the second filter branch 130 are sequentially arranged along the second direction D2 as a fourth row, wherein the ninth filter cavity B9 of the second filter branch 130 is connected to the output end of the filter 100.

By adopting the above arrangement for the filtering cavities 190 in the first filtering branch 120 and the second filtering branch 130, the size of the filtering branches is reduced, and further the size of the filter 100 is reduced, the signal transmission of the filter 100 is not affected, and the performance of the filter 100 is enhanced.

In this embodiment, as shown in fig. 1, eight filter cavities 190 of the first filter branch 120 are sequentially coupled by a window 180; between the first filter cavity B1 and the second filter cavity B2, between the second filter cavity B2 and the third filter cavity B3, between the third filter cavity B3 and the fourth filter cavity B4, between the fourth filter cavity B4 and the fifth filter cavity B5 of the second filter branch 130; between the fifth filter chamber B5 and the sixth filter chamber B6; between the seventh filter chamber B7 and the eighth filter chamber B8; and a metal coupling rib 196 is arranged between the eighth filter cavity B8 and the ninth filter cavity B9. By arranging the metal coupling rib 196, the coupling strength between two adjacent filter cavities 190 on the coupling path is improved, so that the coupling quality of energy transmission is improved.

Fig. 2 is a schematic topology structure diagram of a first filtering branch according to an embodiment of the present application, and as shown in fig. 2 in combination with fig. 1, capacitive cross coupling is respectively performed between a first filtering cavity a1 and a third filtering cavity A3, between a third filtering cavity A3 and a fifth filtering cavity a5, and between a third filtering cavity A3 and a sixth filtering cavity a6 of the first filtering branch 120; inductive cross-coupling between the sixth filter cavity a6 and the eighth filter cavity A8 of the first filter branch 120; the operating frequency band of the first filtering branch 120 is 3700-3800 MHZ.

The inductive cross coupling between the sixth filter cavity a6 and the eighth filter cavity A8 of the first filter branch 120 can well control the high suppression of the bandwidth of the first filter branch 120; capacitive cross coupling is respectively formed between the first filtering cavity A1 and the third filtering cavity A3, between the third filtering cavity A3 and the fifth filtering cavity A5, and between the third filtering cavity A3 and the sixth filtering cavity A6 of the first filtering branch 120; three capacitive coupling zeros and one inductive coupling zero are formed, so that the low-end suppression of the bandwidth of the filter 100 can be well controlled, and better low-end suppression of the bandwidth can be obtained, and therefore, the stop band suppression performance of the filter 100 can be improved; in addition, the operating frequency range of the first filtering branch 120 is 3700-.

Fig. 3 is a schematic topology structure diagram of a second filtering branch according to an embodiment of the present application, and as shown in fig. 3 in combination with fig. 1, capacitive cross coupling is respectively performed between a first filtering cavity B1 and a fourth filtering cavity B4, between a second filtering cavity B2 and a fourth filtering cavity B4, between a sixth filtering cavity B6 and an eighth filtering cavity B8, and between a sixth filtering cavity B6 and a ninth filtering cavity B9 of the second filtering branch 130; inductive cross-coupling between the fourth filter cavity B4 and the sixth filter cavity B6 of the second filter branch 130; the working frequency band of the second filtering branch 130 is 3900-.

The inductive cross coupling between the fourth filter cavity B4 and the sixth filter cavity B6 in the second filter branch 130 can well control the high suppression of the bandwidth of the second filter branch 120; capacitive cross coupling is respectively formed between the first filtering cavity B1 and the fourth filtering cavity B4, between the second filtering cavity B2 and the fourth filtering cavity B4, between the sixth filtering cavity B6 and the eighth filtering cavity B8, and between the sixth filtering cavity B6 and the ninth filtering cavity B9 of the second filtering branch 130; four capacitive coupling zeros and one inductive coupling zero are formed, so that the low-end suppression of the bandwidth of the filter 100 can be well controlled, and better low-end suppression of the bandwidth can be obtained, and therefore, the stop band suppression performance of the filter 100 can be improved; in addition, the working frequency range 3900-.

Fig. 4 is a schematic diagram of an equivalent combination circuit of a first filtering branch and a second filtering branch according to an embodiment of the present application, where different filters have different coupling relationships and may be converted into equivalent resistances, as shown in fig. 4, the first filtering branch 120 has a main coupling relationship between a1 and A8 and is equivalent to a first resistor R1, and the first filtering branch 120 is capacitively cross-coupled between a first filtering cavity a1 and a third filtering cavity A3, between a third filtering cavity A3 and a fifth filtering cavity a5, and between a third filtering cavity A3 and a sixth filtering cavity a 6; equivalent to a second resistor R2; the inductive cross-coupling relationship between the sixth filter cavity a6 and the eighth filter cavity A8 of the first filter branch 120 is equivalent to a third resistor R3.

The second filtering branch 130 has a main coupling relationship between B1 and B9, and is equivalent to a fourth resistor R4; capacitive cross coupling is respectively performed between the first filtering cavity B1 and the fourth filtering cavity B4, between the second filtering cavity B2 and the fourth filtering cavity B4, between the sixth filtering cavity B6 and the eighth filtering cavity B8, and between the sixth filtering cavity B6 and the ninth filtering cavity B9 of the second filtering branch 130, and the capacitive cross coupling is equivalent to a fifth resistor R5; inductive cross-coupling between the fourth filter cavity B4 and the sixth filter cavity B6 of the second filter branch 130; equivalent to a sixth resistor R6.

The impedances Z2 and Z3 at the second and third ports are about 50 ohms, and the impedance Z1 at the output port is about 50 ohms; in order to ensure that electromagnetic signals are transmitted between the nine filter cavities 190 of the filter 10, impedance adjusters Z11 are respectively disposed between the input port and the first filter cavity a1 of the first filter branch, between adjacent filter cavities on the coupling path, between non-cascaded filter cavities forming cross coupling, and between the eighth filter cavity A8 and the output port, and impedance adjusters Z21 are respectively disposed between the input port and the first filter cavity B1 of the second filter branch 130, between adjacent filter cavities 190 on the coupling path, between non-cascaded filter cavities 190 forming cross coupling, and between the ninth filter cavity B9 and the output port, so as to achieve impedance matching.

FIG. 5 is a waveform diagram illustrating a parameter response of a first filtering branch and a second filtering branch combined circuit according to an embodiment of the present application; the suppression of the frequency point 3.700GHz (m3) is-0.886 dB, the suppression of the frequency point 3.800GHz (m4) is-0.954 dB, the suppression of the frequency point 3.900GHz (m5) is-0.897 dB, and the suppression of the frequency point 4.100GHz (m6) is-0.887 dB, so the design requirement of the out-of-band suppression of the filter 10 can be met.

As can be seen from fig. 4 and fig. 5, in the present application, the filter 100 is designed into two filtering branches, and 8-order 4 zeros are formed by eight filtering cavities 190 of one filtering branch, and 9-order 5 zeros are formed by nine filtering cavities 190 of the other filtering branch, where two inductive cross-coupling zeros are respectively formed in the first filtering branch 120 and the second filtering branch 130, so that high-end rejection of the bandwidth of the filtering branches can be well controlled, and good high-end rejection of the bandwidth is obtained; the three capacitive cross-coupling zeros formed in the first filtering branch 120 and the four capacitive cross-coupling zeros formed in the second filtering branch 130 can also well control the low-end rejection of the bandwidth of the filter 100, and obtain a better low-end rejection of the bandwidth, so that the stop-band rejection performance of the filter 100 can be improved.

The cross-coupling zero is also referred to as a transmission zero. The transmission zero is the transmission function of the filter 100 equal to zero, that is, the electromagnetic energy at the frequency point corresponding to the transmission zero cannot pass through the network, so that the complete isolation effect is achieved, the suppression effect on the signals outside the passband is achieved, and the high isolation among a plurality of passbands can be better achieved.

Fig. 6 is a schematic diagram of a partial filter cavity of a filter according to an embodiment of the present invention, and as shown in fig. 6 in combination with fig. 1, in this embodiment, flying rods 170 are respectively disposed between the third filter cavity A3 and the fifth filter cavity a5, between the third filter cavity A3 and the sixth filter cavity a6, and between the sixth filter cavity a6 and the eighth filter cavity A8 of the first filter branch 120; the flying rods 170 are respectively arranged between the first filtering cavity B1 and the fourth filtering cavity B4, between the second filtering cavity B2 and the fourth filtering cavity B4, between the sixth filtering cavity B6 and the eighth filtering cavity B8, and between the sixth filtering cavity B6 and the ninth filtering cavity B9 of the second filtering branch 130; the flying bar 170 includes a first coupling portion 171, a second coupling portion 172, and a connecting portion 173, and two ends of the connecting portion 173 are respectively connected to the first coupling portion 171 and the second coupling portion 172 for coupling the two adjacent filter cavities 190.

Specifically, two ends of the connecting portion 173 are respectively connected to the first coupling portion 171 and the second coupling portion 172, and the first coupling portion 171 and the second coupling portion 172 are located on the same side of the connecting portion 173. The first coupling portion 171, the connecting portion 173, and the second coupling portion 172 are sequentially connected to form the flying bar 170; in the first filtering branch 120 and the second filtering branch 130, two adjacent filtering cavities 190 are provided with windows 180 at positions corresponding to the flying bar 170; a supporting clamping seat 181 is arranged in the window 180, and the flying bar 170 is fixed on the supporting clamping seat 181.

Taking the first filtering branch 120 as an example, the first coupling part 171 is coupled to the resonant rod 191 in the third filtering cavity A3 in the first filtering branch 120, so that a coupling capacitance is formed between the first coupling part 171 and the resonant rod 191, and the second coupling part 172 is coupled to the resonant rod in the fifth filtering cavity a5, so that a coupling capacitance is formed between the second coupling part 172 and the resonant rod 191.

FIG. 7 is a schematic structural diagram of a filter cavity according to an embodiment of the present disclosure; as shown in fig. 7, each of the filter cavities of the first and second filter branches 120 and 130 is provided with a resonance rod 191 and a tuning rod 192; a resonating rod 191 including a sidewall 193 and a hollow lumen 194 formed by the sidewall 193; a tuning rod 192, one end of the tuning rod 192 being disposed within the hollow lumen 194; a flange 195 is arranged on one side of the side wall 193 close to the resonance rod 191, and the resonance rod 191 is made of invar steel.

In order to further enhance the electric coupling, a flange 195 is disposed on a side of the side wall 193 of the resonant cavity close to the resonant rod 191, so that the height of the metal connecting piece can be raised, and the purpose of pulling the resonant rod 191 closer is achieved, thereby enhancing the coupling effect.

The sizes of the 8 filter cavities 190 in the first filter branch 120 and the 9 filter cavities 190 in the second filter branch 130 are the same, and the size of the filter cavity 190 is smaller than phi 30 x 18mm, so that the production is convenient, and the cost is saved. The eight filter cavities 190 in the first filter branch 120 and the nine filter cavities 190 in the second filter branch 130 of the present embodiment may be metal filter cavities, and the resonant rod 191 may be a metal resonant rod 191. The filter 100 in the embodiment of the application has low loss, and can ensure low energy consumption of the communication module; the first filtering branch 120 of the filter 100 is designed by combining the filtering cavities 190 of 8 orders, the second filtering branch 130 of the filter 100 is designed by combining the filtering cavities 190 of 9 orders, and a coupling zero structure is introduced, so that the high-frequency-resistant filter has high anti-interference capability and can ensure that a communication system is not interfered by stray signals; the filter 100 has a simple design scheme, low cost, good structure and stable electrical performance.

Fig. 8 is a schematic structural diagram of a communication device according to an embodiment of the present application, and as shown in fig. 8, a communication device 10 according to the present embodiment includes an antenna 200 and a radio frequency unit 300 connected to the antenna 200, where the radio frequency unit 300 includes a filter 100 as shown in the above embodiment, and the filter 100 is used for filtering a radio frequency signal. The filter 100 of the present application may also adopt a dual low-pass connection mode to enhance the signal transmission effect.

In other embodiments, the rf Unit 300 may be integrated with the Antenna 200 to form an Active Antenna Unit (AAU).

Some embodiments of the present application are referred to as filters 100 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.

It should be noted that the inventive concept of the present application can form many embodiments, but the present application has a limited space and cannot be listed one by one, so that, on the premise of no conflict, any combination between the above-described embodiments or technical features can form a new embodiment, and after the embodiments or technical features are combined, the original technical effect will be enhanced.

The foregoing is a more detailed description of the present application in connection with specific alternative embodiments, and the specific implementations of the present application are not to be considered limited to these descriptions. For those skilled in the art to which the present application pertains, several simple deductions or substitutions may be made without departing from the concept of the present application, and all should be considered as belonging to the protection scope of the present application.

Claims (10)

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

a housing;

the first filtering branch is arranged on the shell and consists of eight filtering cavities which are sequentially coupled, and the eight filtering cavities of the first filtering branch form three capacitive cross-coupling zero points and one inductive cross-coupling zero point;

the second filtering branch is arranged on the shell and consists of nine filtering cavities which are sequentially coupled, and the nine filtering cavities of the second filtering branch form four capacitive cross-coupling zero points and one inductive cross-coupling zero point; and

wherein the first filtering branch and the second filtering branch share an output end of the filter.

2. The filter of claim 1, further comprising:

the output port is respectively connected with the eighth filtering cavity of the first filtering branch circuit and the ninth filtering cavity of the second filtering branch circuit;

the first input end is connected with the first filtering cavity of the first filtering branch circuit;

and the second input end is connected with the first filtering cavity of the second filtering branch circuit.

3. The filter of claim 2, wherein the housing has a first direction and a second direction perpendicular to the first direction; the eight filter cavities of the first filter branch circuit are divided into three rows arranged along the first direction;

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

4. The filter according to claim 3, wherein the nine filter cavities of the second filter branch are divided into four rows arranged along the first direction;

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

5. The filter according to claim 3, wherein capacitive cross coupling elements are respectively arranged between the first filter cavity and the third filter cavity, between the third filter cavity and the fifth filter cavity, and between the third filter cavity and the sixth filter cavity of the first filter branch; an inductive cross coupling element is arranged between the sixth filtering cavity and the eighth filtering cavity of the first filtering branch circuit; the working frequency band of the first filtering branch is 3700-3800 MHZ.

6. The filter according to claim 4, wherein capacitive cross-coupling elements are respectively arranged between the first filter cavity and the fourth filter cavity, between the second filter cavity and the fourth filter cavity, between the sixth filter cavity and the eighth filter cavity, and between the sixth filter cavity and the ninth filter cavity of the second filter branch; an inductive cross coupling element is arranged between a fourth filtering cavity and a sixth filtering cavity of the second filtering branch circuit; the working frequency band of the second filtering branch circuit is 3900-.

7. The filter of claim 5 or 6, wherein the capacitive cross-coupling elements and the inductive cross-coupling elements are flybars;

the flying rod comprises a first coupling part, a second coupling part and a connecting part, wherein two ends of the connecting part are respectively connected with the first coupling part and the second coupling part;

in the first filtering branch and the second filtering branch, a window is arranged at a position corresponding to the flying rod, a supporting clamping seat is arranged in the window, and the flying rod is fixed on the supporting clamping seat.

8. The filter according to claim 2, wherein each of the filter cavities of the first and second filter branches is provided with a resonance rod and a tuning rod; the resonance rod comprises a side wall and a hollow inner cavity formed by the side wall; one end of the tuning rod is arranged in the hollow inner cavity; the side wall is close to one side of resonance pole is provided with the turn-ups, and the resonance pole is made for the invar steel material.

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

and metal coupling ribs are arranged between the first filtering cavity and the second filtering cavity, between the second filtering cavity and the third filtering cavity, between the third filtering cavity and the fourth filtering cavity, between the fourth filtering cavity and the fifth filtering cavity, between the fifth filtering cavity and the sixth filtering cavity, between the seventh filtering cavity and the eighth filtering cavity, and between the eighth filtering cavity and the ninth filtering cavity of the second filtering branch.

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

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