Filter

Abstract

The utility model relates to the technical field of communication, and provides a filter, which comprises a cavity, a capacitive cross coupling structure, and a first resonance piece, a second resonance piece and a third resonance piece which are arranged in the cavity, the cavity is provided with an isolation wall, the isolation wall is provided with a coupling window, the first resonance piece is positioned on one side of the isolation wall, and the third resonance piece is positioned on the other side of the isolation wall. The second resonance part and the third resonance part are located on the other side of the isolation wall, and the second resonance part is in coupling connection with the third resonance part; the capacitive cross coupling structure comprises a first capacitive coupling piece and a second capacitive coupling piece, one end of the first capacitive coupling piece and one end of the second capacitive coupling piece are both connected to the first resonance piece, and the other end of the first capacitive coupling piece and the other end of the second capacitive coupling piece extend towards the second resonance piece and the third resonance piece respectively. Wherein one end of the first capacitive coupling piece and one end of the second capacitive coupling piece are both connected to the first resonance piece, the first capacitive coupling piece and the second capacitive coupling piece do not need to be installed on the isolation wall through two insulation clamping bases, the insulation clamping bases do not need to be assembled, assembling operation is simplified, and the material cost of the filter is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of communication, in particular to a filter. Background Art

[0002] A filter is a device or circuit that processes signals. Its main function is to allow useful signals to pass through as unattenuated as possible and to attenuate useless signals as much as possible. It is often used as a frequency selection device to select the communication signal frequency and filter out clutter or interference signals other than the communication signal frequency. It is widely used in mobile base stations to reduce intermodulation signal interference and generate high-quality communication signals. It is an indispensable device in electronic communication systems.

[0003] The filter includes multiple resonators located in a cavity, and the multiple resonators are coupled to form a filter channel. A flying rod can be set between two non-adjacent resonators on the filter channel to achieve cross-coupling between the two resonators to form a transmission zero point, thereby adjusting the out-of-band suppression of the passband. When two capacitive couplings need to be formed between the resonators with a cross-coupling relationship, two flying rods need to be assembled, and the two flying rods are respectively installed in the cavity through insulating sockets, resulting in the technical problems of multiple material types and complex assembly of the filter. Utility Model Content

[0004] The utility model aims to provide a filter, aiming to solve the technical problems of the existing filters that there are many types of materials and complex assembly.

[0005] The present application provides a filter, the filter comprising a cavity, a capacitive cross-coupling structure, and a first resonator, a second resonator, and a third resonator installed in the cavity, the cavity is provided with a partition wall, the partition wall has a coupling window, the first resonator is located on one side of the partition wall, the second resonator and the third resonator are located on the other side of the partition wall, and the second resonator and the third resonator are coupled and connected;

[0006] The capacitive cross-coupling structure includes a first capacitive coupling component and a second capacitive coupling component, one end of the first capacitive coupling component and the second capacitive coupling component are both connected to the first resonant component, and the other ends of the first capacitive coupling component and the second capacitive coupling component extend toward the second resonant component and the third resonant component, respectively.

[0007] In one embodiment, the first capacitive coupling element and the first resonant element are integrally formed, and / or the second capacitive coupling element and the first resonant element are integrally formed.

[0008] In one embodiment, the first capacitive coupling element and the second capacitive coupling element are integrally formed.

[0009] In one embodiment, the side of the first capacitive coupling element close to the second capacitive coupling element is attached to the second capacitive coupling element; or the side of the second capacitive coupling element close to the first capacitive coupling element is attached to the first capacitive coupling element.

[0010] In one embodiment, projections of the first resonant element and the second resonant element in the thickness direction of the coupling window overlap; and an extension length of the first capacitive coupling element is smaller than an extension length of the second capacitive coupling element.

[0011] In one embodiment, the filter further includes a fourth resonant component installed in the cavity, wherein the fourth resonant component and the first resonant component are located on the same side of the isolation wall, the fourth resonant component is coupled to the first resonant component, and the fourth resonant component is coupled to the third resonant component; the projections of the fourth resonant component and the third resonant component in the thickness direction of the isolation wall overlap.

[0012] In one embodiment, a connection line between the first resonant element and the third resonant element is a first connection line, and the second capacitive coupling element is located on a side of the first connection line close to the first capacitive coupling element.

[0013] In one embodiment, the first capacitive coupling element is bent and disposed close to an end of the second resonant element; and / or the second capacitive coupling element is bent and disposed close to an end of the third resonant element.

[0014] In one embodiment, the first capacitive coupling element is spaced apart from the top of the second resonant element in the height direction, and the projections of the first capacitive coupling element and the second resonant element in the height direction overlap; and / or, the second capacitive coupling element is spaced apart from the top of the third resonant element in the height direction, and the projections of the second capacitive coupling element and the third resonant element in the height direction overlap.

[0015] In one embodiment, the first resonant element includes a supporting portion and a coupling portion, the supporting portion is mounted on the inner bottom wall of the cavity, the coupling portion and the capacitive cross-coupling structure are both sheet structures, the coupling portion is separately connected to the supporting portion, and the first capacitive coupling element and the second capacitive coupling element are connected to the coupling portion.

[0016] The filter provided by the utility model has the following beneficial effects: the first resonant component and the second resonant component located on both sides of the isolation wall realize capacitive coupling through the coupling window with the help of the first capacitive coupling component, and the first resonant component and the third resonant component located on both sides of the isolation wall realize capacitive coupling through the coupling window with the help of the second capacitive coupling component, thereby realizing cross coupling among the first resonant component, the second resonant component and the third resonant component, one end of the first capacitive coupling component and the second capacitive coupling component are both connected to the first resonant component, realizing that the capacitive cross coupling structure is assembled in the cavity, and it is not necessary to use two additional insulating card holders to be installed on the isolation wall, thereby reducing the types of materials such as the insulating card holder, and there is no need to perform the assembly operation of the insulating card holder, and it is also avoided that the small assembly operation space caused by the additional insulating card holder is avoided, the assembly operation is simplified, and the technical problems of many material types and complex assembly of the existing filter are solved, thereby reducing the assembly difficulty of the filter and reducing the material cost of the filter. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0018] Figure 1 A schematic diagram of the structure of a filter provided in an embodiment of the utility model;

[0019] Figure 2 A schematic diagram of the first internal structure of the filter provided by an embodiment of the utility model;

[0020] Figure 3 for Figure 2 Another view of the filter in ;

[0021] Figure 4 for Figure 2 A schematic diagram of connection between the capacitive cross-coupling structure and the first resonant element;

[0022] Figure 5 for Figure 2 The S-parameter response diagram of the filter in;

[0023] Figure 6 A schematic diagram of a second internal structure of a filter provided by an embodiment of the utility model;

[0024] Figure 7 for Figure 6 A schematic diagram of connection between the capacitive cross-coupling structure and the first resonant element;

[0025] Figure 8A third internal structure schematic diagram of a filter provided in an embodiment of the utility model;

[0026] Fig. 9 A fourth internal structure schematic diagram of the filter provided in an embodiment of the utility model.

[0027] Among them, the reference numerals in the figure are:

[0028] 100, cavity; 110, partition wall; 111, coupling window; 120, coupling rib;

[0029] 200, capacitive cross-coupling structure; 201, bending portion; 210, first capacitive coupling element; 220, second capacitive coupling element;

[0030] 301, first resonant component; 302, second resonant component; 303, third resonant component; 304, fourth resonant component; 305, fifth resonant component; 306, sixth resonant component; 307, seventh resonant component; 308, eighth resonant component; 309, ninth resonant component; 310, tenth resonant component; 311, supporting portion; 312, coupling portion;

[0031] 400. Cover plate. DETAILED DESCRIPTION

[0032] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0033] Reference throughout the specification to "one embodiment" or "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present application. Thus, when the phrases "in one embodiment" or "in some embodiments" appear in various places throughout the specification, not all references are to the same embodiment. Furthermore, in one or more embodiments, the particular features, structures, or characteristics may be combined in any suitable manner.

[0034] In the description of the present invention, it should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0035] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features.

[0036] In the present invention, unless otherwise clearly specified and limited, the terms "install", "connect", "connect", "fix" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0037] Combination Figures 1 to 3 The present application provides a filter, including a cavity 100, a capacitive cross-coupling structure 200, and a first resonator 301, a second resonator 302, and a third resonator 303 installed in the cavity 100. The cavity 100 is provided with a partition wall 110, the partition wall 110 has a coupling window 111, the first resonator 301 is located on one side of the partition wall 110, the second resonator 302 and the third resonator 303 are located on the other side of the partition wall 110, and the second resonator 302 is coupled to the third resonator 303.

[0038] The capacitive cross-coupling structure 200 includes a first capacitive coupling element 210 and a second capacitive coupling element 220. One end of the first capacitive coupling element 210 and the second capacitive coupling element 220 are both connected to the first resonant element 301, and the other ends of the first capacitive coupling element 210 and the second capacitive coupling element 220 extend toward the second resonant element 302 and the third resonant element 303, respectively. The first capacitive coupling element 210 and the second resonant element 302 are spaced apart. In this embodiment, no specific requirements are made on the extension length of the first capacitive coupling element 210. The first capacitive coupling element 210 can extend from one side of the isolation wall 110 to the other side of the isolation wall 110 through the coupling window 111, can extend into the coupling window 111, or can be located as a whole on one side of the isolation wall 110 close to the first resonant element 301, as long as the first resonant element 301 and the second resonant element 302 can be capacitively coupled. The second capacitive coupling element 220 and the third resonant element 303 are spaced apart. This embodiment does not make any specific requirements on the extension length of the second capacitive coupling element 220. The second capacitive coupling element 220 can extend from one side of the isolation wall 110 to the other side of the isolation wall 110 through the coupling window 111, can extend into the coupling window 111, or can be located as a whole on a side of the isolation wall 110 close to the first resonant element 301. It is only necessary to enable the first resonant element 301 and the third resonant element 303 to be capacitively coupled.

[0039] The second resonant component 302 and the third resonant component 303 may be coupled and connected via a coupling rib 120, or may be coupled and connected via a coupling rod, a coupling sheet or other coupling structures, or may be coupled and connected via a window, or may be directly coupled via an interval arrangement without any other structure being provided between the two. As long as the two can establish a coupling relationship, this embodiment does not limit the implementation method of the coupling connection between the second resonant component 302 and the third resonant component 303. The coupling relationship between the second resonant component 302 and the third resonant component 303 may be inductive coupling or capacitive coupling.

[0040] Since the first resonant element 301 and the second resonant element 302 located on both sides of the isolation wall 110 are capacitively coupled through the coupling window 111 by means of the first capacitive coupling element 210, the first resonant element 301 and the third resonant element 303 located on both sides of the isolation wall 110 are capacitively coupled through the coupling window 111 by means of the second capacitive coupling element 220, and the second resonant element 302 and the third resonant element 303 are coupled to each other, the first resonant element 301, the second resonant element 302 and the third resonant element 303 are coupled to each other, and cross coupling between the first resonant element 301, the second resonant element 302 and the third resonant element 303 is achieved, and a transmission zero point is generated to enhance the out-of-band suppression of the filter passband.

[0041] In the present embodiment, one end of the first capacitive coupling element 210 and one end of the second capacitive coupling element 220 are both connected to the first resonant element 301, so that the capacitive cross-coupling structure 200 is assembled in the cavity 100. There is no need to use two additional insulating sockets to be installed on the isolation wall 110 or other structures provided in the cavity 100, which reduces the types and quantities of materials such as insulating sockets, eliminates the need for assembling insulating sockets, and avoids the small assembly operation space caused by adding insulating sockets, thereby simplifying the assembly operation and reducing the assembly difficulty and material cost of the filter.

[0042] In addition, the first capacitive coupling element 210 and the second capacitive coupling element 220 do not need to be assembled at the coupling window 111 through an insulating socket, so the coupling window 111 does not need to consider accommodating the insulating socket. The size of the coupling window 111 can be designed more flexibly according to the radio frequency indicators without being restricted by the insulating socket.

[0043] In this embodiment, combined with Figure 3 and Figure 4 The end size of the first capacitive coupling element 210 close to the second resonant element 302 and the distance between the first capacitive coupling element 210 and the second resonant element 302 can be used to independently adjust the capacitive coupling strength between the first resonant element 301 and the second resonant element 302, that is, the capacitive coupling strength between the first resonant element 301 and the second resonant element 302 can be enhanced by increasing the free end width size a of the first capacitive coupling element 210 or increasing the extension length c of the first capacitive coupling element 210; the capacitive coupling strength between the first resonant element 301 and the second resonant element 302 can be weakened by reducing the free end width size a of the first capacitive coupling element 210 or reducing the extension length c of the first capacitive coupling element 210. The end size of the second capacitive coupling element 220 close to the third resonant element 303 and the distance between the second capacitive coupling element 220 and the third resonant element 303 can be used to independently adjust the capacitive coupling strength between the first resonant element 301 and the third resonant element 303, that is, the capacitive coupling strength between the first resonant element 301 and the third resonant element 303 can be enhanced by increasing the free end width size b of the second capacitive coupling element 220 or increasing the extension length of the second capacitive coupling element 220; the capacitive coupling strength between the first resonant element 301 and the third resonant element 303 can be weakened by reducing the free end width size b of the second capacitive coupling element 220 or reducing the extension length of the second capacitive coupling element 220.

[0044] Based on this, the capacitive coupling strength between the first resonant element 301 and the second resonant element 302, and the first resonant element 301 and the third resonant element 303 can be relatively independently regulated, avoiding interference with the other capacitive coupling strength when regulating one capacitive coupling strength, thereby greatly reducing the difficulty and complexity of regulation. At the same time, the filter does not need to introduce external adjustment screws and other components to adjust the coupling strength of the first capacitive coupling element 210 and the second capacitive coupling element 220, saving the types and quantities of materials, simplifying the internal structure of the filter, and being more conducive to the miniaturization design of the filter.

[0045] In some embodiments, in combination Figure 4 The first capacitive coupling component 210 and the first resonant component 301 are integrally formed, that is, there is no need to perform a separate connection operation between the first capacitive coupling component 210 and the first resonant component 301, which greatly reduces assembly errors, reduces assembly difficulty, and improves assembly consistency. In addition, the position accuracy between the first capacitive coupling component 210 and the first resonant component 301 is high, which can ensure the dimensional stability and assembly consistency of the product, thereby improving the stability of product indicators.

[0046] It can be understood that in other embodiments, the first capacitive coupling element 210 and the first resonant element 301 can also be connected by means of but not limited to bonding, welding, threaded connection, fastener connection, snap connection, crimping, plug-in connection, sleeve connection, interference fit and other separate connection methods.

[0047] In some embodiments, in combination Figure 4 The second capacitive coupling component 220 and the first resonant component 301 are integrally formed, that is, there is no need to perform a separate connection operation between the second capacitive coupling component 220 and the first resonant component 301, which greatly reduces assembly errors, reduces assembly difficulty, and improves assembly consistency. In addition, the position accuracy between the second capacitive coupling component 220 and the first resonant component 301 is high, which can ensure the dimensional stability and assembly consistency of the product, thereby improving the stability of product indicators.

[0048] It can be understood that in other embodiments, the second capacitive coupling element 220 and the first resonant element 301 can also be connected by means of but not limited to bonding, welding, threaded connection, fastener connection, snap connection, crimping, plug-in connection, sleeve connection, interference fit and other separate connection methods.

[0049] In some embodiments, in combination Figure 4The first capacitive coupling element 210 and the second capacitive coupling element 220 are integrally formed so that they do not interfere with each other and have high positional accuracy, which can ensure the dimensional stability and assembly consistency of the capacitive cross-coupling structure 200. In addition, the first capacitive coupling element 210 and the second capacitive coupling element 220 are an integral whole, and the assembly of the capacitive cross-coupling structure 200 can be completed by assembling only one of the first capacitive coupling element 210 and the second capacitive coupling element 220 with the first resonant element 301, thereby reducing the number of assembly times of the capacitive cross-coupling structure 200 and reducing the assembly difficulty of the filter.

[0050] In one embodiment, in combination Figure 4 The first capacitive coupling element 210, the second capacitive coupling element 220 and the first resonant element 301 are integrally formed, and there is no need for separate connection operations, which greatly reduces assembly errors, reduces assembly difficulty, improves assembly consistency, and has high positional accuracy between the three, which can ensure the dimensional stability and assembly consistency of the product, thereby improving the stability of product indicators.

[0051] In some embodiments, in combination Figure 3 and Figure 4 , the side of the first capacitive coupling element 210 close to the second capacitive coupling element 220 is attached to the second capacitive coupling element 220, avoiding the generation of a gap between the first capacitive coupling element 210 and the second capacitive coupling element 220, reducing the overall size of the capacitive cross-coupling structure 200, facilitating the design of the coupling window 111 to reduce the signal crosstalk caused by the coupling window 111 being too large. At the same time, one side of the first capacitive coupling element 210 is integrally attached to the second capacitive coupling element 220, and the attachment area is large, so that the bonding force between the first capacitive coupling element 210 and the second capacitive coupling element 220 is large, and the integrity is strong, avoiding the capacitive cross-coupling structure 200 from shaking during use and causing changes in coupling strength, thereby improving the stability of product indicators.

[0052] In some embodiments, the side of the second capacitive coupling element 220 close to the first capacitive coupling element 210 is attached to the first capacitive coupling element 210, which reduces the overall size of the capacitive cross-coupling structure 200 and facilitates the design of reducing the coupling window 111. At the same time, the contact area between the second capacitive coupling element 220 and the first capacitive coupling element 210 is large, so that the bonding force between the first capacitive coupling element 210 and the second capacitive coupling element 220 is large, the integrity is strong, and the position is stable, which improves the stability of product indicators. In particular, one side of the second capacitive coupling element 220 is integrally attached to the first capacitive coupling element 210 to prevent the second capacitive coupling element 220 from being suspended, improve the position stability of the second capacitive coupling element 220, and ensure the stability of the coupling strength between the first resonant element 301 and the third resonant element 303.

[0053] In this embodiment, the coupling window 111 has a thickness direction X, a length direction Y, and a height direction Z which are perpendicular to each other.

[0054] In some embodiments, in combination Figure 2 and Figure 3 , the projections of the first resonant element 301 and the second resonant element 302 in the thickness direction X of the coupling window 111 overlap. Based on this, in the thickness direction X, the first resonant element 301 and the second resonant element 302 are arranged opposite to each other, and the distance between them is short, which increases the opposite area of ​​the two through the coupling window 111, which is conducive to improving the capacitive coupling strength between the two, so that under the condition of meeting the same coupling strength, it is conducive to the design of the first capacitive coupling element 210 to be smaller, including reducing the width dimension a of the free end of the first capacitive coupling element 210 and reducing the extension length c of the first capacitive coupling element 210, so as to avoid the first capacitive coupling element 210 from interfering with other structures due to its excessive size.

[0055] In addition, the first resonant element 301 and the second resonant element 302 are respectively located on both sides of the coupling window 111 along the thickness direction X, and are compactly arranged, which is beneficial to optimizing the cavity structure and facilitating the miniaturization design of the filter.

[0056] In one embodiment, in combination Figure 3 and Figure 4 , the extension length of the first capacitive coupling element 210 is less than the extension length of the second capacitive coupling element 220. Since the first resonant element 301 and the second resonant element 302 are arranged opposite to each other in the thickness direction X, it is beneficial to shorten the first capacitive coupling element 210 to reduce the volume of the capacitive cross-coupling structure 200. At the same time, the first resonant element 301 and the third resonant element 303 are staggered in the thickness direction X. By increasing the length of the second capacitive coupling element 220, it is ensured that the first resonant element 301 and the third resonant element 303 reach a preset coupling strength, so that the lengths of the first capacitive coupling element 210 and the second capacitive coupling element 220 are different, so as to avoid the same length size of the two causing the end size of the capacitive cross-coupling structure 200 to be too large and easy to interfere with other structures.

[0057] In some embodiments, in combination Figure 2 , Figure 3 , Figure 6 , Figure 8 and Fig. 9 The filter further includes a fourth resonant component 304 installed in the cavity 100 . The fourth resonant component 304 and the first resonant component 301 are located on the same side of the isolation wall 110 . The fourth resonant component 304 is coupled to the first resonant component 301 , and the fourth resonant component 304 is coupled to the third resonant component 303 .

[0058] The fourth resonant component 304 and the first resonant component 301, and the fourth resonant component 304 and the third resonant component 303 may be coupled and connected through the coupling rib 120, or may be coupled and connected through a coupling rod, a coupling sheet or other coupling structures, or may be coupled and connected through a window, or may be directly coupled through an interval arrangement without any other structure between the two. As long as the two can establish a coupling relationship, this embodiment does not limit the implementation method of the coupling connection between the fourth resonant component 304 and the first resonant component 301, and between the fourth resonant component 304 and the third resonant component 303. The coupling relationship between the fourth resonant component 304 and the first resonant component 301, and between the fourth resonant component 304 and the third resonant component 303 may be inductive coupling or capacitive coupling.

[0059] Since the first resonant element 301 and the second resonant element 302 located on both sides of the isolation wall 110 are capacitively coupled through the coupling window 111 by means of the first capacitive coupling element 210, the first resonant element 301 and the third resonant element 303 located on both sides of the isolation wall 110 are capacitively coupled through the coupling window 111 by means of the second capacitive coupling element 220, and the second resonant element 302 and the third resonant element 303 are coupled and connected, the fourth resonant element 304 and the first resonant element 301 are coupled and connected, and the fourth resonant element 304 and the third resonant element 303 are coupled and connected, a nested cross-coupling structure is formed among the first resonant element 301, the second resonant element 302, the third resonant element 303 and the fourth resonant element 304, and two transmission zeros can be generated to enhance the out-of-band suppression of the filter passband.

[0060] For example, combined with Figure 5 The first resonant element 301 is capacitively coupled with the second resonant element 302 and the third resonant element 303 through the capacitive cross-coupling structure 200. The second resonant element 302 and the third resonant element 303, the fourth resonant element 304 and the first resonant element 301, and the fourth resonant element 304 and the third resonant element 303 are all inductively coupled. The cross-coupling of the nested structure generates a transmission zero point A and B at the high end and the low end of the passband.

[0061] In some embodiments, in combination Figure 2 , Figure 3 , Figure 6 , Figure 8 and Fig. 9, the projections of the fourth resonant component 304 and the third resonant component 303 in the thickness direction X of the partition wall 110 overlap. Based on this, in the thickness direction X, the fourth resonant component 304 and the third resonant component 303 are arranged opposite to each other, and the distance between them is short, which is conducive to improving the coupling strength between them. In addition, the fourth resonant component 304 and the third resonant component 303 are respectively located on both sides of the partition wall 110 along the thickness direction X, and the arrangement is compact, which is conducive to optimizing the cavity structure and facilitating the miniaturization design of the filter.

[0062] In other embodiments, when the fourth resonant element 304 and the first resonant element 301 are located on the same side of the isolation wall 110 and the fourth resonant element 304 is coupled to the first resonant element 301, the fourth resonant element 304 may not be coupled to the third resonant element 303, but the fourth resonant element 304 is coupled to the second resonant element 302. In this way, a cross-coupling of a nested structure can be formed between the first resonant element 301, the second resonant element 302, the third resonant element 303 and the fourth resonant element 304, generating two transmission zeros.

[0063] In some embodiments, in combination Figure 3 , the connection line between the first resonant element 301 and the third resonant element 303 is the first connection line L, and the second capacitive coupling element 220 is located on the side of the first connection line close to the first capacitive coupling element 210. Based on this, the second capacitive coupling element 220 is arranged close to the first capacitive coupling element 210, which is conducive to reducing the size of the entire capacitive cross-coupling structure 200, reducing the risk of interference with other structures, and reducing the difficulty of arrangement inside the cavity 100; on the other hand, the second capacitive coupling element 220 does not pass through the first connection line L, and the coupling window 111 does not need to be expanded to the first connection line L, which is conducive to the design of reducing the coupling window 111 and avoiding the coupling window 111 being too large and prone to signal crosstalk.

[0064] In some embodiments, in combination Figure 3 , the cross section of the first capacitive coupling element 210 remains unchanged along its extension direction. On the one hand, the first capacitive coupling element 210 has a regular shape along the extension direction, and the signal will not have a sudden change during the transmission process, and the signal transmission is more stable. On the other hand, the cross-sectional shape of the first capacitive coupling element 210 remains unchanged, which can simplify the processing, manufacturing and assembly operations, and improve the production efficiency and dimensional consistency of the capacitive cross-coupling structure 200.

[0065] In some embodiments, in combination Figure 3, the cross section of the second capacitive coupling element 220 remains unchanged along its extension direction. On the one hand, the second capacitive coupling element 220 has a regular shape along the extension direction, and the signal will not have a sudden change during the transmission process, the signal transmission is more stable, and the coupling strength adjustment between the second capacitive coupling element 220 and the third resonant element 303 can be more controllable. On the other hand, the cross-sectional shape of the second capacitive coupling element 220 remains unchanged, which can simplify the processing, manufacturing and assembly operations, and improve the production efficiency and dimensional consistency of the capacitive cross-coupling structure 200.

[0066] In some embodiments, in combination Figure 6 and Figure 7 The first capacitive coupling element 210 is bent at the end close to the second resonant element 302 to increase the coupling area between the first capacitive coupling element 210 and the second resonant element 302, and the coupling strength can be adjusted in a larger range to improve the coupling sensitivity. At the same time, when the same coupling strength is met, the first capacitive coupling element 210 can reduce the width of the free end or reduce the extension length by bending, which is conducive to reducing the size and volume of the first capacitive coupling element 210.

[0067] It should be noted that the end of the first capacitive coupling element 210 close to the second resonant element 302 can be bent along the positive direction of the height direction Z, or can be bent along the negative direction of the height direction Z. The bending direction of the end of the first capacitive coupling element 210 close to the second resonant element 302 can be selected according to the positional relationship of the first capacitive coupling element 210 relative to the top of the second resonant element 302 in the height direction Z, as long as it can be ensured that the first capacitive coupling element 210 and the second resonant element 302 have a sufficient coupling area. For example, when the first capacitive coupling element 210 is located above the top of the second resonant element 302, the end of the first capacitive coupling element 210 close to the second resonant element 302 is bent toward the negative direction of the height direction Z; when the first capacitive coupling element 210 is located below the top of the second resonant element 302, the end of the first capacitive coupling element 210 close to the second resonant element 302 can be bent toward the negative direction of the height direction Z or the positive direction of the height direction Z; when the first capacitive coupling element 210 is flush with the top of the second resonant element 302, the end of the first capacitive coupling element 210 close to the second resonant element 302 is bent toward the negative direction of the height direction Z.

[0068] Specifically, a bending portion 201 extending along the height direction Z is provided at the end of the first capacitive coupling element 210 close to the second resonant element 302, and one side surface of the bending portion 201 faces the second resonant element 302, so that the coupling area between the bending portion 201 and the second resonant element 302 is maximized.

[0069] Optionally, the bent portion 201 may be separately connected to the first capacitive coupling component 210 , or may be integrally formed with the first capacitive coupling component 210 , which is not limited herein.

[0070] In some embodiments, in combination Figure 6 and Figure 7 The second capacitive coupling element 220 is bent at the end close to the third resonant element 303 to increase the coupling area between the second capacitive coupling element 220 and the third resonant element 303, and the coupling strength can be adjusted in a larger range to improve the coupling sensitivity. At the same time, when the same coupling strength is met, the second capacitive coupling element 220 can be bent to reduce its extension length, avoid interference with other structures due to excessive length, and also help reduce the size and volume of the second capacitive coupling element 220.

[0071] It should be noted that the end of the second capacitive coupling element 220 close to the third resonant element 303 can be bent along the positive direction of the height direction Z, or can be bent along the negative direction of the height direction Z. The bending direction of the end of the second capacitive coupling element 220 close to the third resonant element 303 can be selected according to the positional relationship of the second capacitive coupling element 220 relative to the top of the third resonant element 303 in the height direction Z, as long as it can be ensured that the second capacitive coupling element 220 and the third resonant element 303 have a sufficient coupling area. For example, when the second capacitive coupling element 220 is located above the top of the third resonant element 303, the end of the second capacitive coupling element 220 close to the third resonant element 303 is bent toward the negative direction of the height direction Z; when the second capacitive coupling element 220 is located below the top of the third resonant element 303, the end of the second capacitive coupling element 220 close to the third resonant element 303 can be bent toward the negative direction of the height direction Z or the positive direction of the height direction Z; when the second capacitive coupling element 220 is flush with the top of the third resonant element 303, the end of the second capacitive coupling element 220 close to the third resonant element 303 is bent toward the negative direction of the height direction Z.

[0072] In some embodiments, the first capacitive coupling element 210 and the top of the second resonant element 302 are spaced apart in the height direction Z, and the projections of the first capacitive coupling element 210 and the second resonant element 302 in the height direction Z overlap. Based on this, the first capacitive coupling element 210 can extend to the bottom or top of the second resonant element 302, reducing the space between the two, and the projections in the height direction Z overlap, thereby enhancing the capacitive coupling strength between the two and improving the coupling sensitivity, so that when the first capacitive coupling element 210 is thin or the size of the second resonant element 302 is small, the first capacitive coupling element 210 can still maintain effective capacitive coupling with the second resonant element 302, which is beneficial to the lightweight design of the filter.

[0073] It can be understood that in other embodiments, in the projection in the thickness direction X or the height direction Z, the first capacitive coupling element 210 and the second resonant element 302 do not overlap, so as to avoid interference between the first capacitive coupling element 210 and the second resonant element 302 .

[0074] It can be understood that in other embodiments, the first capacitive coupling element 210 is flush with the top of the second resonant element 302 in the height direction Z.

[0075] In some embodiments, the second capacitive coupling element 220 and the top of the third resonant element 303 are spaced apart in the height direction Z, and the projections of the second capacitive coupling element 220 and the third resonant element 303 in the height direction Z overlap. Based on this, the second capacitive coupling element 220 can extend to the bottom or top of the third resonant element 303, reducing the interval between the two, and the projections in the height direction Z overlap, thereby enhancing the capacitive coupling strength between the two and improving the coupling sensitivity, so that when the thickness of the second capacitive coupling element 220 is small or the size of the third resonant element 303 is small, the second capacitive coupling element 220 can still maintain effective capacitive coupling with the third resonant element 303, which is beneficial to the lightweight design of the filter.

[0076] It can be understood that in other embodiments, in the projection in the thickness direction X or the height direction Z, the second capacitive coupling element 220 and the third resonant element 303 do not overlap, so as to avoid interference between the second capacitive coupling element 220 and the third resonant element 303 .

[0077] It can be understood that in other embodiments, the second capacitive coupling element 220 is flush with the top of the third resonant element 303 in the height direction Z.

[0078] In this embodiment, the capacitive cross-coupling structure 200 may be a sheet-like structure, a rod-like structure or a linear structure, which is not limited here. In one embodiment, the capacitive cross-coupling structure 200 is a sheet-like structure, and a first capacitive coupling member 210 and a second capacitive coupling member 220 of a required length can be processed by cutting or punching a flat plate material, and a bending portion 201 can be selectively processed by a bending process, which simplifies the processing technology of the capacitive cross-coupling structure 200 and reduces the processing difficulty. At the same time, the staff can use the same flat plate prototype and obtain multiple capacitive cross-coupling structures 200 of the required shape through machining, which greatly reduces the types of materials to be prepared.

[0079] In some embodiments, in combination Figure 3The first resonant element 301 includes a supporting portion 311 and a coupling portion 312. The supporting portion 311 is installed on the inner bottom wall of the cavity 100. The coupling portion 312 and the capacitive cross-coupling structure 200 are both sheet structures. The coupling portion 312 is separately connected to the supporting portion 311, and the first capacitive coupling element 210 and the second capacitive coupling element 220 are connected to the coupling portion 312. The supporting portion 311 and the coupling portion 312 are manufactured separately, which reduces the difficulty of molding the first resonant element 301. The sheet-shaped coupling portion 312 and the capacitive cross-coupling structure 200 are small in size, which is conducive to reducing the volume of the first resonant element 301 and the capacitive cross-coupling structure 200, thereby reducing the difficulty of assembling the capacitive cross-coupling structure 200, and is conducive to the design of reducing the coupling window 111, and avoiding interference between the capacitive cross-coupling structure 200 and other structures.

[0080] In addition, since the coupling portion 312 is installed on the supporting portion 311, the first capacitive coupling element 210 and the second capacitive coupling element 220 are connected to the coupling portion 312. Therefore, the first capacitive coupling element 210 and the top of the second resonant element 302 can be spaced apart in the height direction Z by raising or lowering the height of the supporting portion 311, and the second capacitive coupling element 220 and the top of the third resonant element 303 can be spaced apart in the height direction Z by raising or lowering the height of the supporting portion 311.

[0081] It can be understood that, since both the coupling portion 312 and the capacitive cross-coupling structure 200 are sheet structures, the first capacitive coupling component 210 and the coupling portion 312 of the first resonant component 301 can be spaced apart in the height direction Z, and the second capacitive coupling component 220 and the coupling portion 312 of the first resonant component 301 can be spaced apart in the height direction Z, thereby achieving a space between the first capacitive coupling component 210 and the top of the second resonant component 302 in the height direction Z, and a space between the second capacitive coupling component 220 and the top of the third resonant component 303 in the height direction Z.

[0082] In one embodiment, the sheet-like coupling portion 312 and the capacitive cross-coupling structure 200 can be integrally formed, with strong integrity, reduced number of components and assembly operations, high connection reliability, high assembly consistency, and the sheet-like structure simplifies the integral molding process, improves the qualified rate of integral molding manufacturing, improves the manufacturing accuracy of the integral molding process, and has a compact structure. It can also be connected in parts, such as but not limited to bonding, welding, threaded connection, fastener connection, snap connection, crimping, plug-in, sleeve connection, interference fit and other split connection methods, which are not limited here. It is not limited here. It can be understood that the coupling portion 312 and the capacitive cross-coupling structure 200 can be integrally formed by stamping, integrally formed by casting, or integrally formed by injection molding and then plated with a metal layer, which is not limited here. In one embodiment, the coupling portion 312 and the support portion 311 can be integrally connected by but not limited to bonding, welding, threaded connection, fastener connection, snap connection, crimping, plug-in, sleeve connection, interference fit and other split connection methods, which are not limited here.

[0083] Specifically, the coupling portion 312 is sleeved on an end of the support portion 311 away from the bottom of the cavity 100. For example, the coupling portion 312 is crimped and fixed to the end of the support portion 311, and the connection method is quick, convenient and reliable. For another example, the coupling portion 312 is hot-melt sleeved or welded to the end of the support portion 311 to increase the bonding force between the coupling portion 312 and the support portion 311.

[0084] In some embodiments, the second resonant member 302 and the third resonant member 303 also include the coupling portion 312 and the supporting portion 311, that is, the second resonant member 302 and the third resonant member 303 are resonant members with the same structural form. Based on this, the consistency of the first resonant member 301, the second resonant member 302 and the third resonant member 303 can be improved. At the same time, the structural form in which multiple resonant members are all installed on the supporting portion 311 using the sheet-shaped coupling portion 312 can greatly utilize the advantages of this structural form, greatly reduce the difficulty of assembly, facilitate the processing and manufacturing of the resonant member, reduce costs, and facilitate the miniaturization and lightweighting of the filter.

[0085] In some embodiments, in combination Figure 2 , Figure 6 , Figure 8 and Fig. 9 The connecting line of the first resonant element 301 and the fourth resonant element 304 is parallel to the isolation wall 110, that is, the intervals between the first resonant element 301 and the fourth resonant element 304 and the isolation wall 110 are the same, so that the first resonant element 301 and the fourth resonant element 304 are arranged in order in the cavity 100, and the isolation interval between the two and the isolation wall 110 can be minimized as much as possible, which is conducive to the cavity arrangement design and the miniaturization design of the filter.

[0086] In some embodiments, in combination Figure 2 , Figure 6 , Figure 8 and Fig. 9 The connecting line of the second resonant element 302 and the third resonant element 303 is parallel to the isolation wall 110, that is, the intervals between the second resonant element 302 and the third resonant element 303 and the isolation wall 110 are the same, so that the second resonant element 302 and the third resonant element 303 are arranged in order in the cavity 100, and the isolation interval between the second resonant element 302 and the isolation wall 110 can be minimized as much as possible, which is conducive to the cavity arrangement design and the miniaturization design of the filter.

[0087] In some embodiments, in combination Figure 2 , Figure 6 , Figure 8 and Fig. 9 , the line connecting the first resonator 301 and the second resonator 302 is perpendicular to the partition wall 110, the line connecting the third resonator 303 and the fourth resonator 304 is perpendicular to the partition wall 110, and the four resonators are distributed in the cavity 100 in a rectangular shape, and the arrangement is compact, which is conducive to the miniaturization design of the cavity 100. Optionally, the first resonator 301 and the second resonator 302 are symmetrically distributed about the partition wall 110, and the third resonator 303 and the fourth resonator 304 are symmetrically distributed about the partition wall 110, so that the isolation interval between the first resonator 301 and the second resonator 302 and the partition wall 110 can be minimized as much as possible, and the isolation interval between the third resonator 303 and the fourth resonator 304 and the partition wall 110 can be minimized as much as possible, which is conducive to the miniaturization design of the filter.

[0088] In some embodiments, in combination Fig. 9 , the first resonator 301, the fourth resonator 304, the third resonator 303 and the second resonator 302 are coupled in sequence through the coupling ribs 120, and the coupling window 111 is located between the first resonator 301 and the second resonator 302. In this way, the first resonator 301, the fourth resonator 304, the second resonator 302 and the third resonator 303 are coupled in sequence to form a main signal channel for signal transmission and filtering. The signal can pass through the first resonator 301, the fourth resonator 304, the second resonator 302 and the third resonator 303 in sequence along the main signal channel, or pass through the third resonator 303, the second resonator 302, the fourth resonator 304 and the first resonator 301 in sequence along the main signal channel. In the main signal channel, the first resonant element 301, the second resonant element 302 and the third resonant element 303 are non-cascaded. The first resonant element 301 is capacitively cross-coupled with the second resonant element 302 through the first capacitive coupling element 210, and is capacitively cross-coupled with the third resonant element 303 through the second capacitive coupling element 220, thereby generating two transmission zeros in the passband.

[0089] It can be understood that in other embodiments, the filter further includes other resonant elements.

[0090] For example, combined with Figure 8 The filter further includes a fifth resonant component 305 and a sixth resonant component 306. The fourth resonant component 304, the first resonant component 301, the fifth resonant component 305, the sixth resonant component 306, the second resonant component 302 and the third resonant component 303 are coupled in sequence to form a main signal channel for signal transmission.

[0091] For example, combining Figure 2 and Figure 6 The filter further includes a fifth resonant component 305, a sixth resonant component 306, and a seventh resonant component 307, an eighth resonant component 308, a ninth resonant component 309 and a tenth resonant component 310 coupled in sequence. The fourth resonant component 304, the first resonant component 301, the fifth resonant component 305, the sixth resonant component 306, the second resonant component 302, the third resonant component 303, the seventh resonant component 307, the eighth resonant component 308, the ninth resonant component 309 and the tenth resonant component 310 are coupled in sequence to form a main signal channel for signal transmission. Optionally, the seventh resonant component 307 and the ninth resonant component 309 are cross-coupled to generate a transmission zero at the high end of the passband, and the seventh resonant component 307 and the tenth resonant component 310 generate parasitic cross-coupling to generate another transmission zero at the high end of the passband.

[0092] In this embodiment, the resonant components including the first resonant component 301 , the second resonant component 302 , the third resonant component 303 and the fourth resonant component 304 can be independently rod-shaped structures, cylindrical structures or sheet-shaped structures.

[0093] In some embodiments, all resonant components including the first resonant component 301, the second resonant component 302, the third resonant component 303 and the fourth resonant component 304 have the same structure, so as to reduce the types of components of the filter and simplify the internal structure of the cavity 100. Among them, the first resonant component 301, the second resonant component 302, the third resonant component 303 and the fourth resonant component 304 can be metal coaxial resonant components, or ceramic dielectric resonant components, ceramic dielectric loaded resonant components, sheet metal resonant components, sheet resonant components, etc., and the present application does not limit the specific types of resonant components.

[0094] Combination Figure 1 The filter further includes a cover plate 400. The cavity 100 has an opening. The cover plate 400 covers one end of the cavity 100 having the opening to form a closed cavity, realize a shielding function, and ensure that the signal in the cavity 100 will not leak.

[0095] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A filter, characterized in that: The filter comprises a cavity, a capacitive cross-coupling structure, and a first resonator, a second resonator and a third resonator installed in the cavity, the cavity is provided with a partition wall, the partition wall has a coupling window, the first resonator is located on one side of the partition wall, the second resonator and the third resonator are located on the other side of the partition wall, and the second resonator is coupled to the third resonator; The capacitive cross-coupling structure includes a first capacitive coupling component and a second capacitive coupling component, one end of the first capacitive coupling component and the second capacitive coupling component are both connected to the first resonant component, and the other ends of the first capacitive coupling component and the second capacitive coupling component extend toward the second resonant component and the third resonant component, respectively.

2. The filter according to claim 1, characterized in that: The first capacitive coupling component and the first resonant component are integrally formed, and / or the second capacitive coupling component and the first resonant component are integrally formed.

3. The filter according to claim 1, characterized in that: The first capacitive coupling component and the second capacitive coupling component are integrally formed.

4. The filter according to claim 1, characterized in that: The side of the first capacitive coupling element close to the second capacitive coupling element is attached to the second capacitive coupling element; or the side of the second capacitive coupling element close to the first capacitive coupling element is attached to the first capacitive coupling element.

5. The filter according to claim 1, characterized in that: The projections of the first resonant element and the second resonant element in the thickness direction of the coupling window overlap; and the extension length of the first capacitive coupling element is smaller than the extension length of the second capacitive coupling element.

6. The filter according to claim 5, characterized in that: The filter further includes a fourth resonant component installed in the cavity, the fourth resonant component and the first resonant component are located on the same side of the isolation wall, the fourth resonant component is coupled to the first resonant component, and the fourth resonant component is coupled to the third resonant component; Projections of the fourth resonator and the third resonator in the thickness direction of the partition wall overlap.

7. The filter according to claim 1, characterized in that: A connection line between the first resonant element and the third resonant element is a first connection line, and the second capacitive coupling element is located on a side of the first connection line close to the first capacitive coupling element.

8. The filter according to claim 1, characterized in that: The first capacitive coupling element is bent and arranged near the end of the second resonant element; And / or, the second capacitive coupling element is bent and disposed close to an end of the third resonant element.

9. The filter according to claim 1, characterized in that: The first capacitive coupling component and the top of the second resonant component are spaced apart in a height direction, and projections of the first capacitive coupling component and the second resonant component in the height direction overlap; And / or, the second capacitive coupling element is spaced apart from the top of the third resonant element in the height direction, and projections of the second capacitive coupling element and the third resonant element in the height direction overlap.

10. The filter according to any one of claims 1 to 9, characterized in that: The first resonant component includes a supporting portion and a coupling portion, the supporting portion is mounted on the inner bottom wall of the cavity, the coupling portion and the capacitive cross-coupling structure are both sheet structures, the coupling portion is separately connected to the supporting portion, and the first capacitive coupling component and the second capacitive coupling component are connected to the coupling portion.

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