CN216354693U - Filter and communication device - Google Patents

Abstract

The application discloses filter and communication device, the filter includes: the filter comprises a shell, a common filter cavity, a first filter branch and a second filter branch, wherein the first filter branch consists of six filter cavities which are coupled in sequence, and the six filter cavities of the first filter branch form two capacitive cross-coupling zero points; the second filtering branch consists of five filtering cavities which are coupled in sequence, and the five filtering cavities of the second filtering branch form two inductive cross-coupling zeros; and the first filter cavity of the first filter branch and the first filter cavity of the second filter branch are respectively coupled with the common filter cavity. This application realizes combining through public filtering chamber, reduces the volume of wave filter, and through forming two capacitive cross coupling zeros at first filtering branch road, forms two inductive coupling zeros at second filtering branch road, improves wave filter stop band rejection performance, reinforcing interference killing feature.

Description

Filter and communication device

Technical Field

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

Background

In a base station system for mobile communication, communication signals carrying communication data in a specific frequency range are generally transmitted through a transmitting antenna, and the communication signals are received through a receiving antenna. The signal received by the receiving antenna contains not only the communication signal carrying the communication data within the specific frequency range, but also a number of spurious or interfering signals outside the specific frequency range. To obtain the communication signal carrying communication data in a specific frequency range transmitted by the transmitting antenna from the signal received by the receiving antenna, the signal received by the receiving antenna is usually filtered by a filter to filter out clutter or interference signals outside the specific frequency of the communication signal carrying communication data.

At present, a cavity filter is generally adopted in a base station system. Due to the difference of the used frequency bands, a filter is needed to divide the frequency bands. Although the electrical performance index of the traditional single-channel filter can be realized, if a plurality of single-channel filters are adopted for frequency division, the traditional single-channel filter not only occupies a large volume and causes high cost, but also is easily influenced by factors such as more stray signal interference, and the like, so that the stop band rejection performance of the cavity filter is poor, and the technical problem to be solved in the field is needed urgently.

SUMMERY OF THE UTILITY MODEL

The purpose of the present application is to provide a filter and a communication device, which can improve the stop band suppression performance of the filter.

The application discloses a filter, the filter includes: the filter comprises a shell, a common filter cavity, a first filter branch and a second filter branch; the common filter cavity is arranged on the shell; the first filtering branch is arranged on the shell and consists of six filtering cavities which are sequentially coupled, and the six filtering cavities of the first filtering branch form two capacitive cross-coupling zeros; the second filtering branch is arranged on the shell and consists of five filtering cavities which are sequentially coupled, and the five filtering cavities of the second filtering branch form two inductive cross-coupling zeros; the filter also comprises an output port, a first input end and a second input end, and the output port is connected with the common filter cavity; the first input end is connected with a sixth filtering cavity of the first filtering branch circuit; the second input end is connected with a fifth filtering cavity of the second filtering branch circuit; and the first filter cavity of the first filter branch and the first filter cavity of the second filter branch are respectively coupled with the common filter cavity.

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

Optionally, the first filter cavity, the second filter cavity, the third filter cavity, the fourth filter cavity, the fifth filter cavity and the sixth filter cavity of the first filter branch are arranged in a parallelogram; and the first filtering cavity, the second filtering cavity, the third filtering cavity, the fourth filtering cavity and the fifth filtering cavity of the second filtering branch are in trapezoidal arrangement.

Optionally, flying rods are respectively disposed between the first filtering cavity and the third filtering cavity of the first filtering branch, and between the third filtering cavity and the fifth filtering cavity of the first filtering branch, and the first filtering cavity and the third filtering cavity of the first filtering branch, and the third filtering cavity and the fifth filtering cavity of the first filtering branch are capacitively and cross-coupled through the flying rods; the working frequency range of the first filtering branch circuit is 811MHz-960 MHz; coupling windows are respectively arranged between the first filtering cavity and the third filtering cavity of the second filtering branch circuit and between the fourth filtering cavity and the fifth filtering cavity of the second filtering branch circuit, and the first filtering cavity and the third filtering cavity and the fourth filtering cavity and the fifth filtering cavity of the second filtering branch circuit are respectively in inductive cross coupling through the coupling windows; the working frequency range of the second filtering branch circuit is 703MHz-788 MHz.

Optionally, each filter cavity is provided with a resonance rod and a tuning rod; the resonance rod comprises a cavity wall and an inner cavity formed by the cavity wall; one end of the tuning rod is arranged in the inner cavity; the resonance rod is made of invar steel materials; the cavity wall comprises a bottom wall and a side wall, two ends of the side wall bend and extend in a direction away from the inner cavity so as to form flanging structures at two ends of the side wall, and the flanging structures are arranged in parallel with the bottom wall; each filtering cavity is further provided with a fixing column, a fixing hole is formed in the position, corresponding to the fixing column, of the bottom wall, and the cavity wall is fixed on the fixing column through the fixing hole.

Optionally, the flanging structure comprises a vertical part and a horizontal part, one end of the horizontal part is connected with the side wall, the other end of the horizontal part is connected with the vertical part, the vertical part is perpendicular to the horizontal part, the vertical part is parallel to the side wall, and the length of the horizontal part is greater than that of the vertical part.

Optionally, a chamfer structure is arranged at the joint of the horizontal part and the side wall, and the chamfer structure is a round chamfer.

Optionally, metal coupling ribs are arranged 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, between the fourth filter cavity and the fifth filter cavity, and between the fifth filter cavity and the sixth filter cavity of the first filter branch; and metal coupling ribs are arranged between the first filtering cavity and the second filtering cavity of the second 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 fourth filtering cavity and the fifth filtering cavity.

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 wave filter for carry out the filtering to radio frequency signal.

The filter is designed into two filtering branches and a common filtering cavity, the two filtering branches are simultaneously connected by the common filtering cavity for combining, six filtering cavities of the first filtering branch form six-order two zero points, and five filtering cavities of the second filtering branch form five-order two zero points, wherein two capacitive cross-coupling zero points formed by the first filtering branch can well control the low-end suppression of the bandwidth of the filtering branches and obtain better low-end suppression of the bandwidth; two inductive cross coupling zeros that form in the second filtering branch road, the high-end suppression of control filtering branch road bandwidth that can be fine, possess strong interference killing feature, ensure that communication system does not receive stray signal interference, and simultaneously, two filtering branch roads are through public filtering chamber coupling connection, the use of cable has been reduced, not only realize the electrical property index of original a plurality of single channel filters, and it is littleer to occupy the volume, be favorable to reducing the volume of wave filter, and because set up capacitive coupling zero in first filtering branch road and carry out the low-end suppression, set up inductive cross coupling zero in the second filtering branch road and carry out high-end suppression, therefore, can improve the stop band rejection performance of wave filter at passband low-end and passband high-end.

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 combined topology diagram of a first filtering branch and a second filtering branch according to an embodiment of the present application;

fig. 5 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. 6 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. 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, a communication device; 100. a filter; 200. an antenna; 300. a radio frequency unit; 110. a housing; 120. a first filtering branch; 130. a second filtering branch; c1, common filter cavity; 140. an output port; 150. a first input terminal; 160. a second input terminal; d1, first direction; d2, second direction; 170. a flying bar; 1801. a coupling window; 190. a filter cavity; 191. a resonant rod; 192. a tuning rod; 193. a chamber wall; 1931. a side wall; 1932. a bottom wall; 194. an inner cavity; 195. a flanging structure; 1951. a vertical portion; 1952. a horizontal portion; 196. A metal coupling rib; 197. fixing a column; 198. a fixing hole; 199. and (5) chamfering structure.

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, where the filter 100 includes: the filter comprises a shell 110, a common filter cavity C1, a first filter branch 120 and a second filter branch 130, wherein the common filter cavity C1 is arranged on the shell 110; the first filtering branch 120 is arranged on the housing 110 and consists of six filtering cavities 190 coupled in sequence, and the six filtering cavities 190 of the first filtering branch 120 form two capacitive cross-coupling zeros; the second filtering branch 130 is arranged on the housing 110 and is composed of five filtering cavities 190 coupled in sequence, and the five filtering cavities 190 of the second filtering branch 130 form two inductive cross-coupling zeros; the first filter cavity a1 of the first filter branch 120 and the first filter cavity B1 of the second filter branch 130 are respectively coupled to the common filter cavity C1.

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 related 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.

According to the filter 100, two filtering branches and a common filtering cavity C1 are designed, the common filtering cavity C1 is used for simultaneously connecting the two filtering branches to form a combined path, six filtering cavities 190 of a first filtering branch form six-order two zero points, and five filtering cavities 190 of a second filtering branch form five-order two zero points, wherein two capacitive cross-coupling zero points formed by the first filtering branch 120 can well control the low-end suppression of the bandwidth of the filtering branches, and better low-end suppression of the bandwidth is obtained; the two inductive cross-coupling zeros formed in the second filtering branch 130 can well control the high-end suppression of the bandwidth of the filtering branch, and have strong anti-interference capability, thereby ensuring that the communication system is not interfered by stray signals. Meanwhile, the first filtering branch 120 and the second filtering branch 130 are coupled and connected through the common filtering cavity C1, so that the use of cables is reduced, the electrical performance indexes of a plurality of original single-channel filters are realized, the occupied size is smaller, the size of the filter is favorably reduced, moreover, because the capacitive coupling zero point is arranged in the first filtering branch for low-end suppression, and the inductive cross coupling zero point is arranged in the second filtering branch for high-end suppression, therefore, the stop band suppression performance of the filter 100 at the low end of the pass band and the high end of the pass band can be improved.

Furthermore, the filter 100 further includes: an output port 140, a first input 150 and a second input 160, the output port 140 being connected to a common filter cavity C1; the first input terminal 150 is connected to the sixth filter cavity a6 of the first filter branch 120; the second input 160 is connected to the fifth filter chamber B5 of the second filter branch 130.

Therefore, the first filtering branch 120 and the second filtering branch 130 share the common filtering cavity C1, the first filtering branch 120 and the second filtering branch 130 can combine the signals together through the common filtering cavity C1 and then output from the output port 140, so that cable connection can be saved, cost is saved, occupied space inside the filter 100 is reduced, meanwhile, the output port 140, the first input end 150 and the second input end 160 are respectively connected with a connector, a connecting rod of the connector extends into an integrated resonance rod, a capacitor sleeve is used on the connecting rod of the connector to prevent contact between the connecting rod and the resonance rod of the connector from short circuit, and finally a strong capacitor is generated between the connecting rod and the resonance rod of the connector to form a tap, in the application, the filter 100 has three taps, so that the signals can be better input and output. The design scheme also adopts a three-low-pass structure, and low-pass rods can be arranged on the connectors of the output port 140, the first input end 150 and the second input end 160, so that the far-end inhibition can be obviously improved.

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 six filter cavities 190 of the first filter branch 120 are divided into two rows arranged along the first direction D1; the first filtering cavity a1, the fourth filtering cavity a4 and the sixth filtering cavity a6 of the first filtering branch 120 are arranged in sequence along the second direction D2; the second filter cavity a2, the third filter cavity A3 and the fifth filter cavity a5 of the first filter branch 120 are arranged in sequence along the second direction D2. The five filter cavities 190 of the second filter branch 130 are divided into two rows arranged along the first direction D1; the second filter cavity B2 and the third filter cavity B3 of the second filter branch 130 are in a row and are sequentially arranged along the second direction D2; the first filter cavity B1, the fourth filter cavity B4 and the fifth filter cavity B5 of the second filter branch 130 are arranged in a row and are sequentially arranged along the second direction D2.

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 six filter cavities 190 of the first filter branch 120 are arranged in two rows, the filter cavity 190 connected with the common filter cavity C1 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, a fourth filter cavity a4 and a sixth filter cavity a6 are sequentially arranged along a second direction D2 as a first row, and the sixth filter cavity a6 is connected with the first input end 150 of the filter 100; the second filter chamber a2, the third filter chamber A3, and the fifth filter chamber a5 are arranged in this order along the second direction D2 as a second row. The first filtering cavity a1, the second filtering cavity a2, the third filtering cavity A3, the fourth filtering cavity a4, the fifth filtering cavity a5 and the sixth filtering cavity a6 of the first filtering branch 120 are arranged in a parallelogram shape;

the five filter cavities 190 of the second filter branch 130 are divided into two rows to be arranged, the filter cavity 190 of the second filter branch 130, which is connected with the common filter cavity C1 of the filter 100, is the first filter cavity B1 of the second filter branch 130, and the first filter cavity B1, the fourth filter cavity B4 and the fifth filter cavity B5 of the second filter branch 130 are sequentially arranged along the second direction D2 as a first row, wherein the fifth filter cavity B5 of the second filter branch 130 is connected with the second input end 160; the second filter chamber B2 and the third filter chamber B3 are arranged in this order in the second direction D2 as a second row. The first filtering cavity a1, the second filtering cavity a2, the third filtering cavity A3, the fourth filtering cavity a4 and the fifth filtering cavity a5 of the second filtering branch 130 are arranged in a trapezoid shape.

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, a metal coupling rib 196 is disposed between the first filtering cavity a1 and the second filtering cavity a2, between the second filtering cavity a2 and the third filtering cavity A3, between the third filtering cavity A3 and the fourth filtering cavity a4, between the fourth filtering cavity a4 and the fifth filtering cavity a5, and between the fifth filtering cavity a5 and the sixth filtering cavity a6 of the first filtering branch 120; metal coupling ribs 196 are arranged between the first filtering cavity B1 and the second filtering cavity B2, between the second filtering cavity B2 and the third filtering cavity B3, between the third filtering cavity B3 and the fourth filtering cavity B4, and between the fourth filtering cavity B4 and the fifth filtering cavity B5 of the second filtering branch 130.

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 the first filtering branch according to the embodiment of the present application, and as shown in fig. 2 in combination with fig. 1, a flying bar 170 is respectively disposed between the first filtering cavity a1 and the third filtering cavity A3, and between the third filtering cavity A3 and the fifth filtering cavity a5 of the first filtering branch 120; the first filter cavity A1 and the third filter cavity A3 of the first filter branch 120 and the third filter cavity A3 and the fifth filter cavity A5 are capacitively and cross-coupled through a flying rod 170; the working frequency band of the first filtering branch 120 is 811MHz-960 MHz.

Capacitive cross coupling is respectively performed between the first filter cavity a1 and the third filter cavity A3, and between the third filter cavity A3 and the fifth filter cavity a5 of the first filter branch 120, so that the low-end suppression of the bandwidth of the first filter branch 120 can be well controlled, and good high-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 of the first filtering branch 120 is 811MHz-960MHz, and the bandwidth of the filtering branch can be accurately controlled. The flying bar is mainly used for realizing the coupling effect between the two filter cavities and is provided with a metal coupling probe.

Fig. 3 is a schematic view of a topology structure of a second filtering branch according to an embodiment of the present disclosure, as shown in fig. 3 in combination with fig. 1, coupling windows 1801 are respectively disposed between a first filtering cavity B1 and a third filtering cavity B3, and between a fourth filtering cavity B4 and a fifth filtering cavity B5 of the second filtering branch 130, and the first filtering cavity B1 and the third filtering cavity B3, and between the fourth filtering cavity B4 and the fifth filtering cavity B5 of the second filtering branch 130 are inductively cross-coupled through the coupling windows 1801; the working frequency band of the second filtering branch 130 is 703MHz-788 MHz.

Inductive cross coupling is respectively performed between the first filter cavity B1 and the third filter cavity B3, between the fourth filter cavity B4 and between the fifth filter cavity B5 of the second filter branch 130; two inductive coupling zeros are formed, so that the high-end rejection of the bandwidth of the filter 100 can be well controlled, and better high-end rejection of the bandwidth is obtained, and therefore, the stop band rejection performance of the filter 100 can be improved; in addition, the operating frequency range of the second filtering branch 130 is 703MHz-788MHz, which can accurately control the bandwidth of the filtering branch.

Fig. 4 is a combined topology diagram of a first filtering branch and a second filtering branch according to an embodiment of the present disclosure, fig. 5 is a schematic diagram of an equivalent combined circuit of the first filtering branch and the second filtering branch according to the present disclosure, as can be seen from fig. 4 and fig. 5, different filters have different coupling relationships and can be equivalently converted into resistors, and 120 in the first filtering branch has a main coupling relationship between a first filtering cavity a1 and a sixth filtering cavity a6, which is equivalently a first resistor R1; capacitive cross coupling is respectively performed between the first filter cavity A1 and the third filter cavity A3 of the first filter branch 120 and between the third filter cavity A3 and the fifth filter cavity A5, and the capacitive cross coupling is equivalent to a second resistor R2.

The second filtering branch 130 has a main coupling relationship between the first filtering cavity B1 and the second filtering cavity B5, and is equivalent to a third resistor R3; the first filter cavity B1 and the third filter cavity B3, the fourth filter cavity B4 and the sixth filter cavity B5 of the second filter branch 130 are inductively cross-coupled, and are equivalent to a fourth resistor R4.

The impedances Z2 and Z3 at the first input 150 and the second input 160 are about 50 ohms, and the impedance Z1 at the output port 140 is about 50 ohms; to ensure that electromagnetic signals are transmitted between the filter cavities 190 of the filter 10, an impedance adjuster Z21 is provided between the output port 140 and the common filter cavity C1; impedance adjusters Z22 are respectively provided between the output port 140 and the first filter cavity a1 of the first filter branch 120, between adjacent filter cavities on the coupling path, between the non-cascaded filter cavities 190 forming the cross coupling and between the sixth filter cavity a6 and the first input terminal 150,

impedance adjusters Z23 are respectively disposed between the output port 140 and the first filter cavity B1 of the second filter branch 130, between adjacent filter cavities 190 on the coupling path, between filter cavities 190 forming cross-coupling, and between the fifth filter cavity B5 and the second input terminal 160, to achieve impedance matching.

Figure 6 is a waveform diagram of a first filter branch and second filter branch combined circuit parameter response of an embodiment of the present application, as can be seen from fig. 6, the suppression of the frequency point 772.6MHz (m45) is-91.334 dB, the suppression of the frequency point 703.0MHz (m35) is-61.379 dB, the suppression of the frequency point 703.0MHz (m47) is-0.153 dB, the suppression of the frequency point 787.4MHz (m46) is-75.950 dB, the suppression of the frequency point 788.0MHz (m36) is-63.192 dB, the suppression of the frequency point 788.0MHz (m50) is-0.304 dB, the suppression of the frequency point 812.3MHz (m53) is-76.411 dB, the suppression of the frequency point 811.0MHz (m37) is-0.246 dB, the suppression of the frequency point 811.0MHz (m51) is-57.882 dB, the suppression of the frequency point 829.4MHz (m54) is-90.935 dB, the suppression of the frequency point 960.0MHz (m44) is-0.132 dB, and the suppression of the frequency point 960.0MHz (m52) is-62.362 dB, so that the filter can meet the requirements for suppression of the design of the frequency point 10.

Fig. 7 is a schematic structural diagram of a filter cavity according to an embodiment of the present application, and as shown in fig. 7, each filter cavity of the first filter branch 120 and the second filter branch 130 is provided with a resonance rod 191 and a tuning rod 192; resonant rod 191 includes a cavity wall 193 and an inner cavity 194 formed by cavity wall 193; one end of the tuning rod 192 is disposed in the inner cavity 194, and the resonant rod 191 is made of invar steel.

The cavity wall 193 includes a bottom wall 1932 and a side wall 1931, two ends of the side wall 1931 bend and extend in a direction away from the inner cavity 194, so as to form flange structures 195 at two ends of the side wall 1931, and the flange structures 195 are arranged in parallel with the bottom wall 1932; each filter cavity 190 is further provided with a fixing column 197, a fixing hole 198 is formed in the position, corresponding to the fixing column 197, of the bottom wall 1932, and the cavity wall 193 is fixed on the fixing column 197 through the fixing hole 198. This provides the resonant rod 191 with better stability. At the same time, the performance of the filter cavity 190 is adjusted by adjusting the distance the tuning rod 192 extends into the internal cavity 194.

Further, the burring structure 195 includes a vertical portion 1951 and a horizontal portion 1952, one end of the horizontal portion 1952 is connected to the sidewall 1931, and the other end is connected to the vertical portion 1951, the vertical portion 1951 is perpendicular to the horizontal portion 1952, the vertical portion 1951 is parallel to the sidewall 1931, and the length of the horizontal portion 1952 is greater than the length of the vertical portion 1951. Therefore, in the space defined by the filter cavity 190, the capacitance can be effectively increased, and the frequency can be reduced, that is, the volume of the tuning rod 192 and the volume of the resonance rod 191 can be effectively reduced under the condition that the requirement of the working frequency band is met, so that the volume of the filter cavity 190 and even the volume of the whole filter 100 can be reduced.

In addition, a chamfer structure 199 is arranged at the joint of the horizontal part 1952 and the side wall 1931, and the chamfer structure 199 is a round chamfer. In the actual production process, sharp edges are easily formed at the connection part of the side wall 1931 and the horizontal part 1952, so that the power is not controlled well; receive the electric field too big, can produce the phenomenon of discharging, influence the filtering effect, consequently set up chamfer structure 199 in the junction of horizontal part 1952 and lateral wall 1931 to adopt the round chamfer to round sharp-edged rounding off, avoid appearing the phenomenon of discharging, increase the stability of filter chamber.

The six filter cavities 190 in the first filter branch 120 and the five 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.

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, the 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 embodiments, and the filter 100 is used for filtering a radio frequency signal.

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 (9)

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

a housing;

a common filter cavity disposed on the housing;

the first filtering branch is arranged on the shell and consists of six filtering cavities which are sequentially coupled, and the six filtering cavities of the first filtering branch form two capacitive cross-coupling zeros;

the second filtering branch is arranged on the shell and consists of five filtering cavities which are sequentially coupled, and the five filtering cavities of the second filtering branch form two inductive cross-coupling zeros;

an output port connected to the common filter cavity;

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

the second input end is connected with a fifth filtering cavity of the second filtering branch circuit;

and the first filter cavity of the first filter branch and the first filter cavity of the second filter branch are respectively coupled with the common filter cavity.

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

the second filtering cavities and the third filtering cavities of the second filtering branch are in a row and are sequentially arranged along the second direction; and 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.

3. The filter according to claim 2, wherein the first, second, third, fourth, fifth and sixth filter cavities of the first filter branch are arranged in a parallelogram; and the first filtering cavity, the second filtering cavity, the third filtering cavity, the fourth filtering cavity and the fifth filtering cavity of the second filtering branch are in trapezoidal arrangement.

4. The filter according to claim 3, wherein flying rods are respectively arranged between the first filter cavity and the third filter cavity of the first filter branch and between the third filter cavity and the fifth filter cavity of the first filter branch, and the first filter cavity and the third filter cavity of the first filter branch and the third filter cavity and the fifth filter cavity of the first filter branch are capacitively and cross-coupled through the flying rods; the working frequency range of the first filtering branch circuit is 811MHz-960 MHz;

coupling windows are respectively arranged between the first filtering cavity and the third filtering cavity of the second filtering branch circuit and between the fourth filtering cavity and the fifth filtering cavity of the second filtering branch circuit, and the first filtering cavity and the third filtering cavity and the fourth filtering cavity and the fifth filtering cavity of the second filtering branch circuit are respectively in inductive cross coupling through the coupling windows; the working frequency range of the second filtering branch circuit is 703MHz-788 MHz.

5. The filter according to claim 1, wherein each of the filter cavities is provided with a resonance rod and a tuning rod; the resonance rod comprises a cavity wall and an inner cavity formed by the cavity wall; one end of the tuning rod is arranged in the inner cavity; the resonance rod is made of invar steel materials;

the cavity wall comprises a bottom wall and a side wall, two ends of the side wall bend and extend in a direction away from the inner cavity so as to form flanging structures at two ends of the side wall, and the flanging structures are arranged in parallel with the bottom wall;

each filtering cavity is further provided with a fixing column, a fixing hole is formed in the position, corresponding to the fixing column, of the bottom wall, and the cavity wall is fixed on the fixing column through the fixing hole.

6. The filter of claim 5, wherein the flanging structure comprises a vertical portion and a horizontal portion, one end of the horizontal portion is connected to the sidewall, the other end of the horizontal portion is connected to the vertical portion, the vertical portion is perpendicular to the horizontal portion, the vertical portion is parallel to the sidewall, and the length of the horizontal portion is greater than that of the vertical portion.

7. The filter of claim 6, wherein a junction of the horizontal portion and the side wall is provided with a chamfer structure, and the chamfer structure is a round chamfer.

8. The filter according to claim 1, wherein metal coupling ribs are arranged 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, between the fourth filter cavity and the fifth filter cavity, and between the fifth filter cavity and the sixth filter cavity of the first filter branch;

and metal coupling ribs are arranged between the first filtering cavity and the second filtering cavity of the second 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 fourth filtering cavity and the fifth filtering cavity.

9. 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 1-8 for filtering a radio frequency signal.

Images