CN216214004U - Filter and communication device - Google Patents

Abstract

The application discloses wave filter and communication equipment, the wave filter includes: the filter circuit comprises a shell, a filter branch, an input port and an output port, wherein the filter branch is arranged on the shell and consists of nine filter cavities which are coupled in sequence; the input port is connected with a first filtering cavity of the filtering branch circuit; the output port is connected with a ninth filtering cavity of the filtering branch circuit; the second filtering cavity and the fourth filtering cavity of the filtering branch circuit are arranged between the first filtering cavity and the fourth filtering cavity; the second filtering cavity and the fifth filtering cavity are capacitively and crossly coupled to form two capacitive coupling zeros; the bandwidth range of the filtering branch circuit is 3400MHz-3800 MHz. 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 filters, in particular to a filter and communication equipment.

Background

With the progress of society and the continuous development of communication equipment, the filter becomes the key equipment of the current mobile communication system and is widely applied to wireless communication base stations and various communication terminals; the 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 the passband range, and the filter structure has a blocking function on signals outside the resonant frequencies, so that the function of selecting microwave transmission signals is realized; however, 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 rejection performance of the cavity filter is poor.

How to enhance the stop-band rejection performance of the filter becomes a problem to be solved urgently in the field.

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 also discloses a filter, the filter includes: the filter comprises a shell, a filtering branch, an input port and an output port; the filtering branch is arranged on the shell and consists of nine filtering cavities which are coupled in sequence; the input port is connected with a first filtering cavity of the filtering branch circuit; the output port is connected with a ninth filtering cavity of the filtering branch circuit; capacitive cross coupling is performed between a second filtering cavity and a fourth filtering cavity of the filtering branch circuit and between the second filtering cavity and a fifth filtering cavity of the filtering branch circuit, so that two capacitive coupling zeros are formed; the bandwidth range of the filtering branch circuit is 3400MHz-3800 MHz.

Optionally, the housing has a first direction and a second direction, and the first direction is perpendicular to the second direction; the first filtering cavities and the seventh filtering cavities of the filtering branch are arranged in a row and are sequentially arranged in a straight line along the first direction; the second filtering cavity, the fifth filtering cavity, the sixth filtering cavity, the eighth filtering cavity and the ninth filtering cavity of the filtering branch are arranged in a row and are sequentially arranged in a straight line along the first direction; the third filtering cavity and the fourth filtering cavity of the filtering branch are arranged in a row and are arranged in sequence in a straight line in the first direction.

Optionally, the second filtering cavity in the filtering branch is arranged corresponding to a midpoint of a connecting line of the third filtering cavity and the fourth filtering cavity, and the third filtering cavity, the fourth filtering cavity and the fourth filtering cavity are arranged in a triangle; the first filtering cavity of the filtering branch circuit is arranged corresponding to the middle point of the connecting line of the second filtering cavity and the fifth filtering cavity and is arranged in a triangular shape; the fourth filtering cavity of the filtering branch circuit is arranged corresponding to the middle point of the connecting line of the second filtering cavity and the fifth filtering cavity and is arranged in a triangular shape; the seventh filtering cavity of the filtering branch is arranged corresponding to the middle point of the connecting line of the sixth filtering cavity and the eighth filtering cavity and is arranged in a triangular shape; and the second filtering cavity, the third filtering cavity, the fourth filtering cavity and the fifth filtering cavity of the filtering branch are arranged in a parallelogram shape.

Optionally, each filter cavity of the filter branch is provided with a resonance rod and a tuning rod; the resonant rod comprises a cavity wall and a cavity enclosed by the cavity wall, and one end of the tuning rod is arranged in the cavity; the resonance rod is made of free-cutting steel.

Optionally, the cavity wall is U-shaped, the cavity wall includes a side wall and a bottom wall, the side wall surrounds the bottom wall for a circle and is connected to the bottom wall, the top of the side wall bends and extends in a direction away from the cavity to form a flange structure at the top of the side wall, and the flange structure is parallel to the bottom wall; each filtering cavity of the filtering branch is also provided with a fixed column, and the cavity wall is fixed on the fixed column.

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

Optionally, a first flying bar and a second flying bar are respectively arranged between the second filtering cavity and the fourth filtering cavity of the filtering branch and between the second filtering cavity and the fifth filtering cavity of the filtering branch for capacitive cross coupling; the first flying bar and the second flying bar respectively comprise a first coupling part, a second coupling part and a dielectric block, and the first coupling part and the second coupling part are respectively connected with the dielectric block; windows are arranged between the second filtering cavity and the fourth filtering cavity of the filtering branch circuit and between the second filtering cavity and the fifth filtering cavity of the filtering branch circuit, and the first flying rod and the second flying rod are correspondingly arranged in the windows.

Optionally, the first coupling portion and the second coupling portion are symmetrically disposed on two sides of the dielectric block, and both the first coupling portion and the second coupling portion are metal coupling probes; the first coupling part comprises a first protruding part and a second protruding part, the connecting parts of the first protruding part and the second protruding part are connected to the dielectric block, and the first protruding part and the second protruding part both extend in a bending mode towards the direction departing from the dielectric block; the second coupling part comprises a third protruding part and a fourth protruding part, one end of the third protruding part is connected with one end of the fourth protruding part, and the other ends of the third protruding part and the fourth protruding part extend towards the direction deviating from the dielectric block in a bending mode.

Optionally, the length of the first protrusion is greater than the length of the second protrusion, and the length of the third protrusion is greater than the length of the fourth protrusion; the first coupling part of the first flying rod is connected with the second filter cavity of the filter branch circuit, and the second coupling part is connected with the fourth filter cavity of the filter branch circuit; the first coupling part of the second flying rod is connected with the second filter cavity of the filter branch circuit, and the second coupling part is connected with the fifth filter cavity of the filter branch circuit; the second protruding portion of the first fly rod and the second protruding portion of the second fly rod are disposed close to each other.

The application also discloses a communication device, the communication device includes antenna and radio frequency unit, the antenna with the radio frequency unit is connected, the radio frequency unit includes the aforesaid wave filter.

The filter is designed with nine filter cavities of one filter branch to form nine-order two capacitive coupling zeros, namely, the nine-order capacitive coupling zeros pass between a second filter cavity and a fourth filter cavity of the filter branch; the second filtering cavity and the fifth filtering cavity are capacitively and crossly coupled to form two capacitive coupling zeros; the working frequency band of the stop band rejection performance of the filter can be improved to be 3400-3800 MHz, and the bandwidth of the filtering branch can be accurately controlled. The device has the advantages of low in-band loss and strong anti-interference capability.

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 partial structural diagram of a filter according to an embodiment of the present application;

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

fig. 3 is a schematic diagram of an equivalent circuit of a filter branch according to an embodiment of the present application;

FIG. 4 is a waveform diagram illustrating a parameter response of a filter branch circuit according to an embodiment of the present application;

FIG. 5 is a schematic structural diagram of a filter cavity according to an embodiment of the present disclosure;

FIG. 6 is a schematic structural diagram of a fly rod in an embodiment of the present application;

fig. 7 is a schematic structural diagram of a communication device according to an embodiment of the present application.

10, communication equipment; 100. a filter; 110. a housing; 120. a filtering branch circuit; 200. an antenna; 300. a radio frequency unit; 140. an input port; 150. an output port; d1, first direction; d2, second direction; 170. a flying bar; 1701. a first fly rod; 1702. a second fly rod; 171. a first coupling part; 172. a second coupling part; 174. a first protrusion; 175. a second protrusion; 176. a third projection; 177. a fourth protrusion; 180. a window; 181. a dielectric block; 190. a filter cavity; 191. a resonant rod; 192. a tuning rod; 193. a chamber wall; 1931 side walls; 1932. a bottom wall; (ii) a 194. A cavity; 195. a flanging structure; 196. a metal coupling rib; 197. mounting holes; 198. and (5) fixing the column.

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 partial structure diagram of a filter according to an embodiment of the present application, and fig. 2 is a schematic topological structure diagram of a filtering branch according to an embodiment of the present application; as shown in fig. 1 in conjunction with fig. 2, the present application discloses a filter 100, the filter 100 comprising: the filter comprises a shell 110, a filter branch 120, an input port 140 and an output port 150, wherein the filter branch 120 is arranged on the shell 110 and consists of nine filter cavities which are coupled in sequence; the input port 140 is connected to the first filter cavity a1 of the filter branch 120; the output port 150 is connected to the ninth filter cavity a9 of the filter branch 120; wherein, the second filter cavity a2 and the fourth filter cavity a4 of the filter branch 120; the second filter cavity A2 and the fifth filter cavity A5 are capacitively cross-coupled to form two capacitively coupled zeros; the bandwidth of the filtered branch 120 is 3400MHz-3800 MHz.

In the present application, a filter 100 is designed with nine filter cavities of one filter branch 120 to form nine-order 2 capacitive coupling zeros, that is, the nine-order 2 capacitive coupling zeros pass between the second filter cavity a2 and the fourth filter cavity a4 of the filter branch 120; the second filter cavity A2 and the fifth filter cavity A5 are capacitively cross-coupled to form two capacitively coupled zeros; the stop band rejection performance of the filter 100 can be improved, and the filter has the advantages of low in-band loss and strong anti-interference capability. The working frequency band is 3400-3800 MHz, and the bandwidth of the filtering branch circuit 120 can be accurately controlled.

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.

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

Specifically, as shown in fig. 1, the housing 110 has a first direction D1 and a second direction D2 perpendicular to the first direction D1; the nine filter cavities of the filter branch 120 are divided into five rows arranged along the first direction D1, and the first filter cavity a1, the second filter cavity a2 and the third filter cavity A3 of the filter branch 120 are arranged along the second direction D2 as a row; the fourth filter cavity a4 and the fifth filter cavity a5 of the filter branch 120 are arranged in a row along the second direction D2; the sixth filter cavity a6 and the seventh filter cavity a7 of the filter branch 120 are arranged in a row along the second direction D2; the eighth filter cavities A8 of the filter branch 120 are arranged in a row along the second direction D2; the ninth filter cavities a9 of the filter branch 120 are arranged in a row along the second direction D2.

Because this application has adopted the filtering branch road 120 that nine filtering chambeies formed to form, the filtering chamber quantity in the wave filter 100 is more, consequently has carried out the design of arranging to the filtering chamber on the filtering branch road 120, specifically arranges as follows:

the first filtering cavity a1 and the seventh filtering cavity a7 of the filtering branch 120 are arranged in a row and are sequentially arranged in a straight line along the first direction D1; the second filtering cavity a2, the fifth filtering cavity a5, the sixth filtering cavity a6, the eighth filtering cavity A8 and the ninth filtering cavity a9 of the filtering branch 120 are arranged in a row and are sequentially arranged in a straight line along the first direction D1; the third filter cavity A3 and the fourth filter cavity a4 of the filter branch 120 are arranged in a row and are sequentially arranged in a straight line along the first direction D1.

Further, the second filtering cavity a2 in the filtering branch 120 is arranged corresponding to the midpoint of the connecting line between the third filtering cavity A3 and the fourth filtering cavity a4, and the three are arranged in a triangle; the first filtering cavity a1 of the filtering branch 120 is arranged corresponding to the midpoint of the connecting line between the second filtering cavity a2 and the fifth filtering cavity a5, and the three are arranged in a triangle; the fourth filtering cavity a4 of the filtering branch 120 is arranged corresponding to the midpoint of the connecting line between the second filtering cavity a2 and the fifth filtering cavity a5, and the three are arranged in a triangle; the seventh filtering cavity a7 of the filtering branch 120 is arranged corresponding to the midpoint of the connecting line between the sixth filtering cavity a6 and the eighth filtering cavity A8, and the seventh filtering cavity a7, the sixth filtering cavity a6 and the eighth filtering cavity A8 are arranged in a triangle; and the second filtering cavity a2, the third filtering cavity A3, the fourth filtering cavity a4 and the fifth filtering cavity a5 of the filtering branch 120 are arranged in a parallelogram. The triangular arrangement makes the arrangement among the filter cavities 190 more compact, and further reduces the volume occupied by the filter cavities 190.

By adopting the above arrangement manner for the nine filtering cavities in the filtering branch 120, the size of the filtering branch 120 is reduced, the size of the filter 100 is further reduced, the signal transmission of the filter 100 is not affected, and the performance of the filter 100 is enhanced. The plurality of filter cavities of the filter branch 120 are arranged in a straight line, so that the structure can be simplified, and the design and the arrangement are facilitated.

In this embodiment, as shown in fig. 1, metal coupling ribs 196 are disposed between the first filter cavity a1 and the second filter cavity a2, between the second filter cavity a2 and the third filter cavity A3, between the third filter cavity A3 and the fourth filter cavity a4, and between the eighth filter cavity A8 and the ninth filter cavity a9 of the filter branch 120. By arranging the metal coupling rib 196, the coupling strength between two adjacent filter cavities on the coupling path is improved, and therefore the coupling quality of energy transmission is improved.

FIG. 3 is a schematic diagram of an equivalent circuit of a filter branch circuit according to the present application; as shown in fig. 3, the filter branch 120 has a main coupling relationship between a1 and a9, which is equivalent to a first resistor R1, between the second filter cavity a2 and the fourth filter cavity a4 of the filter branch 120; the capacitive cross coupling between the second filter cavity a2 and the fifth filter cavity a5 is equivalent to a second resistor R2.

The impedance Z1 at the input port 140 is about 50 ohms and the impedance Z2 at the output port 150 is about 50 ohms; to ensure transmission of electromagnetic signals between the nine filter cavities of the filter 100, impedance adjusters Z11 and Z21 are required to be respectively disposed between the input port 140 and the first filter cavity a1, between adjacent filter cavities on the coupling path, between non-cascaded filter cavities forming cross coupling, and between the ninth filter cavity a9 and the output port 150, so as to achieve impedance matching.

FIG. 4 is a waveform diagram of a parameter response of a filter branch circuit according to an embodiment of the present application; as shown in fig. 4, the bandwidth of the filter 100 of this embodiment is about 3400MHz-3800 MHz; as shown by a frequency band curve, the suppression of the frequency point 3.36200GHz (m3) is-32.50605 dB, the suppression of the frequency point 3.34200GHz (m8) is-35.46751 dB, the suppression of the frequency point 3.25100GHz (m9) is-52.58218 dB, the suppression of the frequency point 3.10100GHz (m10) is-77.53622 dB, the suppression of the frequency point 3.84000GHz (m11) is-32.36996 dB, the suppression of the frequency point 3.86000GHz (m12) is-34.51763 dB, the suppression of the frequency point 3.95000GHz (m13) is-48.53463 dB, and the suppression of the frequency point 4.40000GHz (m14) is-97.54166 dB, so that the design requirement of out-of-band suppression of the filter 100 can be met.

Fig. 5 is a schematic structural diagram of filter cavities according to an embodiment of the present application, each filter cavity of the filter branch 120 is provided with a resonance rod 191 and a tuning rod 192; the resonant rod 191 comprises a cavity wall 193 and a cavity 194 formed by the cavity wall 193, and one end of the resonant rod 192 is arranged in the cavity 194; the resonant rod 191 is made of a free-cutting steel material.

Nine filter cavities in the filter branch circuit 120 are the same in size, and the size of the resonant cavity is smaller than 30 × 18mm, so that the production is facilitated, and the cost is saved. The nine filter cavities in the filter branch 120 of the present embodiment may be metal filter cavities, and the resonant rod 191 may be a metal resonant rod 191.

The cavity wall 193 is U-shaped, the cavity wall 193 comprises a side wall 1931 and a bottom wall 1932, the side wall 1931 surrounds the bottom wall 1932 for a circle and is connected with the bottom wall 1932, the top of the side wall 1931 extends in a bending manner in a direction away from the cavity 194 so as to form a flange structure 195 at the top of the side wall 1931, and the flange structure 195 is arranged in parallel with the bottom wall 1932; in order to further strengthen the electric coupling, a flange structure 195 is arranged on one side of the cavity wall 193 of the resonant cavity close to the resonant rod 191, so that the height of the metal connecting sheet can be raised, and the purpose of drawing the resonant rod 191 close is achieved, thereby enhancing the coupling effect.

Each filtering cavity of the filtering branch circuit 120 is further provided with a fixed column, and the cavity wall 193 is fixed on the fixed column. The resonant beam 191 may be secured to the housing 110 by a fixed post and the resonant frequency of the resonant cavity may be adjusted by adjusting the depth of the tuning rod 192 within the cavity 194.

The resonant rod 191, the cavity 194, and the tuning rod 192 of the present embodiment are coaxially disposed, or may be disposed coaxially, but not limited to this embodiment.

Further, a mounting hole 197 may be further provided on the bottom of the U-shaped cavity wall 193, that is, the bottom wall 1932, one end of the fixing column 198 is fixed on the housing 110, and the other end of the fixing column 198 is mounted in the mounting hole 197, so as to fix the resonance rod 191 on the fixing column 198; the mounting hole 197 may be a through hole or a threaded hole, and the fixing post is a stud.

Fig. 6 is a schematic view of a flying bar in an embodiment of the present application, as shown in fig. 6. A first flying rod 1701 and a second flying rod 1702 are respectively arranged between the second filter cavity A2 and the fourth filter cavity A4 and between the second filter cavity A2 and the fifth filter cavity A5 of the filter branch 120; the first flying bar 1701 and the second flying bar 1702 both include a first coupling portion 171, a second coupling portion 172 and a dielectric block 181, and the first coupling portion 171 and the second coupling portion 172 are connected to the dielectric block 181 respectively; windows 180 are arranged between the second filter cavity A2 and the fourth filter cavity A4 of the filter branch 120 and between the second filter cavity A2 and the fifth filter cavity A5, and the first flying bar 1701 and the second flying bar 1702 are correspondingly arranged in the windows 180.

The first coupling part 171, the dielectric block 181, and the second coupling part 172 are sequentially connected to form the flying bar 170; taking the coupling between the second filter cavity a2 and the fourth filter cavity a4 in the filter branch 120 as an example, the first coupling portion 171 of the first flying bar 1701 is coupled to the resonant rod 191 in the second filter cavity a2, so that a coupling capacitance is formed between the first coupling portion 171 and the resonant rod 191, and the second coupling portion 172 is coupled to the resonant rod 191 in the fourth filter cavity a4, so that a coupling capacitance is formed between the second coupling portion 172 and the resonant rod 191.

Specifically, the first flying bar 1701 and the second flying bar 1702 may be capacitive coupling probes, and coupling capacitors may be formed between the capacitive coupling probes and two adjacent filter cavities by mounting the capacitive coupling probes on the dielectric block 181. In addition, the capacitive coupling probe of the present embodiment may be made of a metal probe, and the dielectric block 181 is made of PTFE or engineering plastic.

As shown in fig. 6, the first coupling part 171 and the second coupling part 172 are symmetrically disposed on both sides of the dielectric block 181, and both the first coupling part 171 and the second coupling part 172 are metal coupling probes; the first coupling part 171 includes a first protrusion 174 and a second protrusion 175, one end of the first protrusion 174 is connected with one end of the second protrusion 175, the other ends of the first protrusion 174 and the second protrusion 175 are both bent and extended in a direction away from the dielectric block 181, the shape enclosed by the first protrusion 174 and the second protrusion 175 matches the shape of the cavity wall 193, and the length of the first protrusion 174 is greater than that of the second protrusion 175; the second coupling part 172 includes a third protrusion 176 and a fourth protrusion 177, one end of the third protrusion 176 is connected with one end of the fourth protrusion 177, the other ends of the third protrusion 176 and the fourth protrusion 177 are both bent and extended in a direction away from the dielectric block 181, the shape enclosed by the third protrusion 176 and the fourth protrusion 177 matches with the shape of the cavity wall 193, and the length of the third protrusion 176 is greater than the length of the fourth protrusion 177.

In an actual installation process, a metal coupling probe is installed on a dielectric block 181 to form a flying bar 170, the flying bar 170 is correspondingly installed in a window 180 between a second filter cavity a2 and a fourth filter cavity a4 of a filter branch 120, and a second filter cavity a2 and a fifth filter cavity a5 respectively to form capacitive cross coupling, taking a second filter cavity a2 and a fourth filter cavity a4 of the filter branch 120 as an example, a first coupling part 171 formed by a first protrusion 174 and a second protrusion 175 is attached to a cavity wall 193 of a second filter cavity a2 to form a coupling capacitor, and a second coupling part 172 formed by a third protrusion 176 and a fourth protrusion 177 is attached to a cavity wall 193 of a fourth filter cavity a4 to form a coupling capacitor, so that signal loss is reduced, and coupling effect is enhanced.

The length of the first protrusion 174 is greater than that of the second protrusion 175, the length of the third protrusion 175 is greater than that of the fourth protrusion 177, the first coupling portion 171 of the first fly rod 1701 is connected to the second filter cavity a2 of the filter branch 120, and the second coupling portion 172 is connected to the fourth filter cavity a4 of the filter branch 120; the first coupling part 171 of the second flying bar 1702 is connected with the second filter cavity a2 of the filter branch 120, and the second coupling part 172 is connected with the fifth filter cavity a5 of the filter branch 120; the second protrusion 175 of the first fly rod 1701 and the second protrusion 175 of the second fly rod 1702 are disposed close to each other. Thus, two flying rods 170 can be connected to one filter cavity 190, further enhancing the coupling effect and saving space.

The filter 100 in the embodiment of the application has low loss, and can ensure low energy consumption of the communication module; the filtering branch 120 of the filter 100 is designed by combining 9-order resonant cavities and introducing a coupling zero structure, so that the filter has strong 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. 7 is a schematic structural diagram of an embodiment of a communication device of the present application, and as shown in fig. 7, the communication device 10 of 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 200 (AAU).

The filter 100 in some embodiments of the present application may also be referred to as a combiner, i.e., a dual-frequency combiner. 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 filtering branch is arranged on the shell and consists of nine filtering cavities which are coupled in sequence;

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

the output port is connected with the ninth filtering cavity of the filtering branch circuit;

capacitive cross coupling is performed between a second filtering cavity and a fourth filtering cavity of the filtering branch circuit and between the second filtering cavity and a fifth filtering cavity of the filtering branch circuit, so that two capacitive coupling zeros are formed; the bandwidth range of the filtering branch circuit is 3400MHz-3800 MHz.

2. The filter of claim 1, wherein the housing has a first direction and a second direction, the first direction being perpendicular to the second direction; the first filtering cavities and the seventh filtering cavities of the filtering branch are arranged in a row and are sequentially arranged in a straight line along the first direction; the second filtering cavity, the fifth filtering cavity, the sixth filtering cavity, the eighth filtering cavity and the ninth filtering cavity of the filtering branch are arranged in a row and are sequentially arranged in a straight line along the first direction; the third filtering cavity and the fourth filtering cavity of the filtering branch are arranged in a row and are arranged in sequence in a straight line in the first direction.

3. The filter according to claim 2, wherein the second filter cavity in the filter branch is arranged corresponding to a midpoint of a connecting line of the third filter cavity and the fourth filter cavity, and the third filter cavity, the fourth filter cavity and the fourth filter cavity are arranged in a triangle; the first filtering cavity of the filtering branch circuit is arranged corresponding to the middle point of the connecting line of the second filtering cavity and the fifth filtering cavity and is arranged in a triangular shape; the fourth filtering cavity of the filtering branch circuit is arranged corresponding to the middle point of the connecting line of the second filtering cavity and the fifth filtering cavity and is arranged in a triangular shape; the seventh filtering cavity of the filtering branch is arranged corresponding to the middle point of the connecting line of the sixth filtering cavity and the eighth filtering cavity and is arranged in a triangular shape;

and the second filtering cavity, the third filtering cavity, the fourth filtering cavity and the fifth filtering cavity of the filtering branch are arranged in a parallelogram shape.

4. The filter according to claim 1, characterized in that each filter cavity of the filter branches is provided with a resonance rod and a tuning rod; the resonant rod comprises a cavity wall and a cavity enclosed by the cavity wall, and one end of the tuning rod is arranged in the cavity; the resonance rod is made of free-cutting steel.

5. The filter according to claim 4, wherein the cavity wall is U-shaped, the cavity wall comprises a side wall and a bottom wall, the side wall surrounds the bottom wall for a circle and is connected with the bottom wall, the top of the side wall is bent and extended in a direction away from the cavity to form a flanging structure at the top of the side wall, and the flanging structure is arranged in parallel with the bottom wall; each filtering cavity of the filtering branch is also provided with a fixed column, and the cavity wall is fixed on the fixed column.

6. The filter according to claim 2, wherein metal coupling ribs are disposed between the first filter cavity and the second filter cavity, between the second filter cavity and the third filter cavity, between the third filter cavity and the fourth filter cavity, and between the eighth filter cavity and the ninth filter cavity of the filter branch.

7. The filter according to claim 2, wherein a first flying bar and a second flying bar are respectively arranged between the second filter cavity and the fourth filter cavity and between the second filter cavity and the fifth filter cavity of the filter branch circuit for capacitive cross coupling; the first flying bar and the second flying bar respectively comprise a first coupling part, a second coupling part and a dielectric block, and the first coupling part and the second coupling part are respectively connected with the dielectric block;

windows are arranged between the second filtering cavity and the fourth filtering cavity of the filtering branch circuit and between the second filtering cavity and the fifth filtering cavity of the filtering branch circuit, and the first flying rod and the second flying rod are correspondingly arranged in the windows.

8. The filter of claim 7, wherein the first coupling part and the second coupling part are symmetrically disposed on two sides of the dielectric block, and both the first coupling part and the second coupling part are metal coupling probes;

the first coupling part comprises a first protruding part and a second protruding part, the connecting parts of the first protruding part and the second protruding part are connected to the dielectric block, and the first protruding part and the second protruding part both extend in a bending mode towards the direction departing from the dielectric block;

the second coupling part comprises a third protruding part and a fourth protruding part, one end of the third protruding part is connected with one end of the fourth protruding part, and the other ends of the third protruding part and the fourth protruding part extend towards the direction deviating from the dielectric block in a bending mode.

9. The filter of claim 8, wherein the length of the first protrusion is greater than the length of the second protrusion, and the length of the third protrusion is greater than the length of the fourth protrusion;

the first coupling part of the first flying rod is connected with the second filter cavity of the filter branch circuit, and the second coupling part is connected with the fourth filter cavity of the filter branch circuit; the first coupling part of the second flying rod is connected with the second filter cavity of the filter branch circuit, and the second coupling part is connected with the fifth filter cavity of the filter branch circuit; the second protruding portion of the first fly rod and the second protruding portion of the second fly rod are disposed close to each other.

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

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