WO2020014980A1 - Cross-coupling structure and cavity filter - Google Patents

Abstract

A cross-coupling structure (20) and a cavity filter (100). The cavity filter (100) comprises a filter cavity (10); the filter cavity (10) comprises a first resonant cavity (11), a second resonant cavity (12), and a third resonant cavity (13); a passage (17) is provided between the first resonant cavity (11) and the second resonant cavity (12) which are arranged oppositely; the third resonant cavity (13) is communicated with the passage (17); the crossing-coupling structure (20) comprises a connection line (21), a tap (22), a first bridging sheet (23), and a second bridging sheet (24); the connection line (21) is accommodated in the passage (17) and extends to the third resonant cavity (13); the tap (22) is disposed in the third resonant cavity (13) and is connected to the end of the connection line (21); the first resonant cavity (11) is provided with a first window (111); the first bridging sheet (23) is connected to the connection line (21) and extends to the interior of the first resonant cavity (11) through the first window (111); the second resonant cavity (12) is provided with a second window (121); and the second bridging sheet (24) is connected to the connection line (21) and extends to the interior of the second resonant cavity (12) through the second window (121). The cavity filter (100) can meet the requirement of specified electrical property even with a small size.

Description

Cross-coupling structure and cavity filter Ranch

[Technical Field]

The invention relates to the technical field of communication radio frequency, in particular to a cross-coupling structure and a cavity filter.

 【Background technique】

With the rapid development of mobile communications, the demand for cavity RF devices such as filters, duplexers, and combiners is increasing, and at the same time, the requirements for their quality and performance are also higher. Considering the limited spectrum resources and the need to save power, RF devices are required to have small insertion loss, large out-of-band rejection, and small volume. In most cases, cross-coupling is required to meet the requirements of electrical performance indicators.

At present, the cross-coupling used by RF devices is divided into capacitive and inductive. The cross-coupling amount corresponds to the cavity structure. After the coupling amount is determined, the corresponding internal structure is also determined. In order to improve the electrical performance of the filter, a capacitor structure and an inductor structure are usually loaded between the resonators. For a capacitor structure, please refer to FIG. 1. A window 230 is opened between the two resonators 210 and 220, and a fixed position is provided at the window 230. Dielectric material 240, a gap (not shown) is formed through the dielectric material 240, and the metal coupling rod 250 is snapped into the gap and fixed to realize a capacitor structure.

In the long-term research, the inventor of the present application found that in the case of fixing the structure of the cavity filter, the positions of the input end and the output end, the traditional method of loading the capacitor structure and the inductance structure cannot make the cavity filter generate at the low end. With zero transmission points, electrical performance cannot be met.

 [Summary of the Invention]

The present invention provides a cross-coupling structure and a cavity filter, in order to solve the problem that in the prior art, the structure of the cavity filter, the position of the input end, and the position of the output end, the traditional way of loading the capacitor structure and the inductor structure cannot The cavity filter generates three transmission zeros at the low end, which cannot meet the technical problem of electrical performance indicators.

To solve the above technical problem, one technical solution of the present invention is to provide a cross-coupling structure applied to a cavity filter, the cavity filter including a filter cavity, and the filter cavity including a first resonance Cavity, a second resonant cavity, and a third resonant cavity, a channel is opened between the first resonant cavity and the second resonant cavity, and is oppositely disposed, and the third resonant cavity is in communication with the channel;

The cross-coupling structure includes a connection line, a tap, a first open circuit piece, and a second open circuit piece;

Wherein, the connection line is accommodated in the channel and extends to the third resonant cavity;

The tap is disposed in the third resonant cavity and is connected to an end of the connection line;

A first window is opened in the first resonant cavity of the first resonant cavity close to the channel, and the first open circuit piece is connected to the connection line and extends into the first resonant cavity through the first window. ;

A second window of the second resonant cavity adjacent to the channel is provided with a second window, and the second open circuit piece is connected to the connection line and extends into the second resonant cavity through the second window. .

To solve the above technical problem, another technical solution of the present invention is to provide a cavity filter, including:

The filter cavity includes a first resonant cavity, a second resonant cavity, and a third resonant cavity. A channel is opened between the first resonant cavity and the second resonant cavity, and the third resonant cavity is oppositely disposed. Communicating with the channel;

A first cross-coupling structure, including a connection line, a tap, a first open circuit piece, and a second open circuit piece;

Wherein, the connection line is accommodated in the channel and extends to the third resonant cavity;

The tap is disposed in the third resonant cavity and is connected to an end of the connection line;

A first window is opened in the first resonant cavity of the first resonant cavity close to the channel, and the first open circuit piece is connected to the connection line and extends into the first resonant cavity through the first window. ;

A second window of the second resonant cavity adjacent to the channel is provided with a second window, and the second open circuit piece is connected to the connection line and extends into the second resonant cavity through the second window. .

Different from the situation of the prior art, the cross-coupling structure provided by the present invention connects the first open circuit piece, the second open circuit piece and the tap through a connection line, and extends to the first resonant cavity and the second resonant cavity of the filter cavity, respectively And the third resonant cavity, so that two transmission zeros are generated at the low end, which can meet the specified electrical performance requirements of the cavity filter when the structure, position of the input end and the output end of the cavity filter are limited, and, The filter cavity is small in size, simple in structure, easy to assemble, and can achieve high out-of-band suppression requirements, thereby effectively reducing costs.

 [Brief Description of the Drawings]

In order to explain the technical solutions in the embodiments of the present invention more clearly, the drawings used in the description of the embodiments are briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without paying creative labor, of which:

1 is a schematic structural diagram of an implementation manner of a filter cavity in the prior art;

2 is a schematic top view of a filter cavity in a cavity filter according to an embodiment of the present invention;

3 is a schematic structural diagram of the filter cavity shown in FIG. 2 at another angle;

4 is an exploded view of the filter cavity shown in FIG. 3;

5 is a simulation circuit diagram of the cavity filter shown in FIG. 2;

FIG. 6 is a response curve diagram of the cavity filter shown in FIG. 2.

【detailed description】

In the following, the technical solutions in the embodiments of the present invention will be clearly and completely described with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by a person of ordinary skill in the art without making creative efforts shall fall within the protection scope of the present invention.

Please refer to FIG. 2, FIG. 3, and FIG. 4, an embodiment of the present invention provides a cavity filter 100, which includes a filter cavity 10, a first cross-coupling structure 20, and a second cross-coupling structure. 30. A first coupling screw 40, a second coupling screw 50, a plurality of resonators 60, and a plurality of resonant rods 70. The filter cavity 10 includes a first resonant cavity 11, a second resonant cavity 12, a third resonant cavity 13, The fourth resonant cavity 14, the fifth resonant cavity 15, and a plurality of isolation ribs. The plurality of isolation ribs include a first isolation rib 161, a second isolation rib 162, and a third isolation rib 163.

The first resonant cavity 11 and the second resonant cavity 12 are provided with a channel 17 therebetween, and the third resonant cavity 13 is in communication with the channel 17. In this embodiment, the first resonant cavity 11, the second resonant cavity 12 and the third resonant cavity 13 are arranged in a triangle line.

The first cross-coupling structure 20 includes a connecting wire 21, a tap 22, a first open circuit piece 23, a second open circuit piece 24, and a fixing member 25.

The connecting line 21 is accommodated in the channel 17 and extends to the third resonant cavity 13. In this embodiment, the connection line 21 is in a sheet shape and is placed in the channel 17 in an upright manner. Further, the connection line 21 is in an “L” shape. Of course, in other embodiments, the shape and setting manner of the connecting wire 21 can be adjusted according to requirements, which is not limited herein.

The tap 22 is disposed in the third resonant cavity 13 and is connected to an end of the connection line 21. In this embodiment, the tap 22 is provided on the top side of the connection line 21.

The first resonance cavity 161 of the first resonant cavity 11 adjacent to the channel 17 is provided with a first window 111. The first open piece 23 is connected to the connection line 21 and extends into the first resonant cavity 11 through the first window 111.

The second isolation rib 162 of the second resonant cavity 12 adjacent to the channel 17 is provided with a second window 121. The second open circuit piece 24 is connected to the connection line 21 and extends into the second resonant cavity 12 through the second window 121.

Please refer to FIG. 4 in combination, the fixing member 25 is used for fixing the connecting wire 21 in the channel 17. In this embodiment, the fixing member 25 is provided with a groove 251. The fixing member 25 is covered on the connecting wire 21, and the connecting wire 21 is embedded in the groove 251. The width of the fixing member 25 is equal to the width of the channel 17, so that the fixing member 25 is fixedly disposed in the channel 17, thereby fixing the connecting wire 21 in the channel 17. Further, the groove 251 is a “U” -shaped groove.

In this embodiment, the connecting wire 21, the tap 22, the first open circuit piece 23, and the second open circuit piece 24 are integrally formed. The first open circuit piece 23 and the second open circuit piece 24 may be “L” shaped. Of course, in other embodiments, the first open circuit piece 23 and the second open circuit piece 24 may also have other shapes, which are not limited herein.

It can be understood that the length, width, and height of the first open circuit piece 23 and the second open circuit piece 24 will affect the amount of coupling. Therefore, the length of the first open circuit piece 23 and the second open circuit piece 24, The width is not limited here.

It can be understood that the first cross-coupling structure 20 connects the first open circuit piece 23, the second open circuit piece 24, and the tap 22 through the connection line 21, and extends to the first resonant cavity 11 and the second resonant cavity of the filter cavity 10, respectively. 12 and the third resonant cavity 13 so that two transmission zeros are generated at the low end. For the case that the structure, position of the input end and the output end of the cavity filter 100 are limited, the specified electrical performance of the cavity filter 100 can be satisfied. Claim.

The fourth resonant cavity 14 and the third resonant cavity 13 are separated by a third isolation rib 163, and the second cross-coupling structure 30 is fixed on the third isolation rib 163.

Specifically, the second cross-coupling structure 30 includes a mounting member 31 and a cross-coupling structure 32. The mounting member 31 is provided with a through hole (not shown). The cross-coupling structure 32 passes through the through hole and is fixed on the mounting member 31. The third isolation rib 163 is provided with a notch 141, and the mounting member 31 is fixedly disposed at the notch 141, so that the second cross coupling structure 30 is fixedly disposed on the third isolation rib 163.

Optionally, the fifth resonant cavity 15 is disposed between the first resonant cavity 11 and the fourth resonant cavity 14, and is disposed adjacent to the third resonant cavity 13. In this embodiment, the first resonant cavity 11, the fifth resonant cavity 15, and the fourth resonant cavity 14 are sequentially arranged, the second resonant cavity 12 and the third resonant cavity 13 are sequentially arranged, and the third resonant cavity 13 and the fifth resonant cavity are sequentially arranged. 15 Same as the central axis. Of course, in other embodiments, the arrangement of the first resonant cavity 11, the second resonant cavity 12, the third resonant cavity 13, the fourth resonant cavity 14, and the fifth resonant cavity 15 can be adaptively adjusted according to requirements. This is not limited.

A first coupling window 151 is provided between the fifth resonant cavity 15 and the third resonant cavity 13, and a first coupling screw 40 is provided at the first coupling window 151. A first coupling window 151 is provided between the fifth resonant cavity 15 and the fourth resonant cavity 14. The two coupling windows 152 are disposed on the second coupling window 152.

A plurality of resonators 60 are respectively disposed in the first resonant cavity 11, a second resonant cavity 12, a third resonant cavity 13, a fourth resonant cavity 14, and a fifth resonant cavity 15, and a plurality of resonant rods 70 are respectively disposed in the corresponding resonant cavity. Within the resonator 60.

Optionally, a boss 80 is disposed in each resonant cavity, and a plurality of resonators 60 are disposed on the boss 80 in the corresponding resonant cavity. Wherein, the boss 80 may be integrally formed with the filter cavity 10.

Further, referring to FIG. 5, the filter cavity 10 includes an input terminal 91 and an output terminal 92. The input terminal 91 is located at an end of the connection line 21, and the output terminal 92 is disposed in the fourth resonant cavity 14 away from the fifth resonant cavity 15. On the side walls.

Please refer to FIG. 6, which is a response curve diagram of the cavity filter 100 provided by the present invention. As can be seen from the figure, when the structure of the cavity filter 100 and the positions of the input end 91 and the output end 92 are fixed, the cavity filter 100 provided by the embodiment of the present invention can generate three transmissions at the low end. Zero point, where m3 refers to the transmission zero point generated by the first cross-coupling structure 20, and m4 refers to the transmission zero point generated by the second cross-coupling structure 30.

Different from the prior art, the first cross-coupling structure 20 in the cavity filter 100 provided by the embodiment of the present invention connects the first open piece 23, the second open piece 24, and the tap 22 through the connecting line 21, and extends to The first resonant cavity 11, the second resonant cavity 12, and the third resonant cavity 13 of the filter cavity 10 generate two transmission zeros at the low end. For the structure defining the cavity filter 100, the input 91, and In the case of the position of the output terminal 92, it can meet the specified electrical performance requirements of the cavity filter 100. In addition, the filter cavity 10 has a small volume, a simple structure, and is easy to assemble. cost.

The above is only an embodiment of the present invention, and thus does not limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made by using the description and drawings of the present invention, or directly or indirectly used in other related technical fields All are included in the patent protection scope of the present invention.

Claims (15)

1. A cross-coupling structure applied to a cavity filter, characterized in that the cavity filter includes a filter cavity, and the filter cavity includes a first resonant cavity, a second resonant cavity, and a third resonant cavity A channel is provided between the first resonant cavity and the second resonant cavity and is oppositely disposed, and the third resonant cavity is in communication with the channel;

   The cross-coupling structure includes a connection line, a tap, a first open circuit piece, and a second open circuit piece;

   Wherein, the connection line is accommodated in the channel and extends to the third resonant cavity;

   The tap is disposed in the third resonant cavity and is connected to an end of the connection line;

   A first window is opened in the first resonant cavity of the first resonant cavity close to the channel, and the first open circuit piece is connected to the connection line and extends into the first resonant cavity through the first window. ;

   A second window of the second resonant cavity adjacent to the channel is provided with a second window, and the second open circuit piece is connected to the connection line and extends into the second resonant cavity through the second window. .
2. The cross-coupling structure according to claim 1, wherein the cross-coupling structure further comprises a fixing member for fixing the connection line in the channel.
3. The cross-coupling structure according to claim 2, wherein the fixing member is provided with a groove, the fixing member is covered on the connection line, and the connection line is embedded in the groove.
4. The cross-coupling structure according to claim 1, wherein the connection line, the tap, the first open circuit piece and the second open circuit piece are integrally formed.
5. The cross-coupling structure according to claim 1, wherein each of the first open circuit piece and the second open circuit piece has an "L" shape.
6. A cavity filter, comprising:

   The filter cavity includes a first resonant cavity, a second resonant cavity, and a third resonant cavity. A channel is opened between the first resonant cavity and the second resonant cavity, and the third resonant cavity is oppositely disposed. Communicating with the channel;

   A first cross-coupling structure, including a connection line, a tap, a first open circuit piece, and a second open circuit piece;

   Wherein, the connection line is accommodated in the channel and extends to the third resonant cavity;

   The tap is disposed in the third resonant cavity and is connected to an end of the connection line;

   A first window is opened in the first resonant cavity of the first resonant cavity close to the channel, and the first open circuit piece is connected to the connection line and extends into the first resonant cavity through the first window. ;

   A second window of the second resonant cavity adjacent to the channel is provided with a second window, and the second open circuit piece is connected to the connection line and extends into the second resonant cavity through the second window. .
7. The cavity filter according to claim 6, wherein the first cross-coupling structure further comprises a fixing member, and the fixing member is used for fixing the connection line in the channel.
8. The cavity filter according to claim 7, wherein the fixing member is provided with a groove, the fixing member is covered on the connection line, and the connection line is embedded in the groove. .
9. The cavity filter according to claim 6, wherein the connection line, the tap, the first open circuit piece and the second open circuit piece are integrally formed.
10. The cavity filter according to claim 6, wherein each of the first open circuit piece and the second open circuit piece has an "L" shape.
11. The cavity filter according to claim 6, wherein the cavity filter further comprises a second cross-coupling structure, the filter cavity further comprises a fourth resonant cavity, and the fourth resonant cavity and The third resonant cavity is separated by a third isolation rib, and the second cross-coupling structure is fixedly disposed on the third isolation rib.
12. The cavity filter according to claim 11, wherein the second cross-coupling structure includes a mounting member and a cross-coupling structure, the mounting member is provided with a through hole, and the cross-coupling structure passes through the through The hole is fixed on the mounting member.
13. The cavity filter according to claim 11, wherein the filter cavity further comprises a fifth resonant cavity, a first coupling screw, and a second coupling screw, and the fifth resonant cavity is disposed at the first A resonant cavity and the fourth resonant cavity are disposed adjacent to the third resonant cavity;

    A first coupling window is provided between the fifth resonant cavity and the third resonant cavity, and the first coupling screw is disposed at the first coupling window;

    A second coupling window is provided between the fifth resonant cavity and the fourth resonant cavity, and the second coupling screw is disposed at the second coupling window.
14. The cavity filter according to claim 13, wherein the cavity filter further comprises a plurality of resonators, and the plurality of resonators are respectively disposed in the first resonance cavity and the second resonance. Cavity, the third resonant cavity, the fourth resonant cavity, and the fifth resonant cavity.
15. The cavity filter according to claim 14, wherein the cavity filter further comprises a plurality of resonance rods, and the plurality of resonance rods are respectively disposed on the corresponding resonators.