Electromagnetic hybrid coupling structure, filter and multiplexer

Abstract

The invention provides an electromagnetic hybrid coupling structure, which is arranged in a filter and comprises a dielectric plate, an electric coupling plate, a first coupling screw rod, a first metal arc-shaped plate, a second metal arc-shaped plate and two resonators, the metal layer surface of the dielectric plate is provided with a coupling gap; the electric coupling plate is fixedly arranged in the coupling gap, and two ends of the electric coupling plate are respectively connected with the first metal arc-shaped plate and the second metal arc-shaped plate; the first metal arc-shaped plate and the second metal arc-shaped plate are symmetrically distributed relative to the first coupling screw rod; each resonator and the first metal arc-shaped plate or the second metal arc-shaped plate are coaxially arranged in the filter, and the resonators are connected through coupling connecting ribs to form a magnetic coupling structure. The electric coupling structure and the magnetic coupling structure are independently arranged, and in the debugging process, the electric coupling strength and the magnetic coupling strength can be correspondingly debugged by adjusting the size and the position of the first coupling screw rod and the coupling rib.

Description

Technical Field

[0001] The present invention belongs to the technical field of wire communication microwave filters, and particularly relates to an electromagnetic hybrid coupling structure, a filter and a multiplexer. Background Art

[0002] With the rapid development of modern wireless communication technologies, radio spectrum resources have become increasingly crowded and precious. In order to fully optimize the utilization rate of spectrum resources and reduce interference, microwave filters with high frequency selection characteristics play a crucial role. Metal coaxial cavity filters are widely used in microwave wireless communication systems due to their advantages such as high reliability, low insertion loss (high Q value), large power capacity, good heat dissipation characteristics, mature production processes and simple debugging.

[0003] Among them, the out-of-band rejection characteristic is an important electrical performance index of the filter. Generally, the out-of-band rejection characteristic of the filter can be improved by two methods: increasing the order of the filter and introducing transmission zeros. Increasing the order of the filter often causes an increase in the external dimensions and insertion loss of the filter, and also increases the cost and the difficulty of product design.

[0004] Without increasing the order of the filter, introducing transmission zeros to improve the out-of-band rejection characteristic of the filter is the most widely used method. Different from the traditional method of introducing cross-coupling between non-adjacent resonant units to generate transmission zeros, electromagnetic hybridization means that when there are both electrical coupling paths and magnetic coupling paths between two adjacent or non-adjacent resonant units, and the magnitudes of the electrical coupling and the magnetic coupling are comparable, new transmission zeros will be generated, thereby improving the out-of-band rejection of the filter.

[0005] At present, electromagnetic hybridization is relatively common in the design of planar structure filters such as microstrip, substrate integrated waveguide and coplanar waveguide. However, its electromagnetic hybrid coupling structure is complex and difficult to debug, and it is not suitable for mass production applications. How to improve the electromagnetic coupling structure to solve the debugging problem is an important development direction of current filters. Summary of the Invention

[0006] In order to solve the problem of how to improve the electromagnetic coupling structure to solve the debugging problem described in the background art, the present invention proposes the following technical solutions:

[0007] An electromagnetic hybrid coupling structure is provided inside a filter, comprising: a dielectric plate, an electric coupling plate, a first coupling screw, a first metal arc plate, a second metal arc plate, and two resonators; the dielectric plate is detachably provided at the open end of the filter, and metal layers are respectively provided on two opposite wide surfaces of the dielectric plate, and a coupling notch is provided on the surface of the metal layer close to the filter side; the electric coupling plate is fixedly provided in the coupling notch, and two ends of the electric coupling plate are respectively connected to the first metal arc plate and the second metal arc plate; one end of the first coupling screw passes through the coupling notch and enters the filter, and the first metal arc plate and the second metal arc plate are symmetrically distributed with respect to the first coupling screw; each resonator is coaxially arranged with the first metal arc plate or the second metal arc plate inside the filter, and the resonators are connected by coupling connecting ribs to form a magnetic coupling structure.

[0008] Wherein, the openings of the first metal arc plate and the second metal arc plate are arranged facing each other, and the diameter of the first metal arc plate is larger than the diameter of the resonator.

[0009] Furthermore, a resonance cavity is provided inside each resonator, and there is a coupling interval between the open end of each resonator and the coupling notch.

[0010] Furthermore, a plurality of mounting holes for fixing a second coupling screw are provided in the coupling notch, and each of the mounting holes is symmetric with respect to the first coupling screw.

[0011] Furthermore, a protective layer formed by electroplating is provided on the outer peripheral surface of each resonator.

[0012] Furthermore, the electric coupling plate divides the coupling notch into a left side part and a right side part, and the projected area of each resonator on the dielectric plate is smaller than the area of the left side part or the area of the right side part.

[0013] Furthermore, there is a coupling gap between the electric coupling plate and the metal layer.

[0014] Another object of the present invention is to provide a filter, comprising: a base and a plurality of the above-mentioned electromagnetic hybrid coupling structures; a filtering cavity with an opening is provided inside the base, one side of each electromagnetic hybrid coupling structure is detachably connected to the bottom surface of the filtering cavity, and the other side of each electromagnetic hybrid coupling structure is detachably connected to the open end of the base; connectors are respectively provided through both sides of the base, and each electromagnetic hybrid coupling structure is fixedly connected to enclose the filtering cavity.

[0015] Further, each of the electromagnetic hybrid coupling structures is arranged in sequence along the length direction of the base in the filtering cavity, and one side close to the filtering cavity between adjacent electromagnetic hybrid coupling structures is connected by the coupling connecting rib.

[0016] Another object of the present invention is to provide a multiplexer, which includes a plurality of the above electromagnetic coupling structures.

[0017] Beneficial effects: By independently providing the electric coupling structure and the magnetic coupling structure, during the debugging process, the electric coupling strength and the magnetic coupling strength can be respectively adjusted by adjusting the sizes and positions of the first coupling screw and the coupling connecting rib to complete the corresponding debugging. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 FIG. is an exploded schematic view of an electromagnetic hybrid coupling structure according to an embodiment of the present invention;

[0019] Figure 2 FIG. is an exploded schematic view of a dielectric plate according to an embodiment of the present invention;

[0020] Figure 3 FIG. is a sectional schematic view of an electromagnetic hybrid coupling structure according to an embodiment of the present invention;

[0021] Figure 4 FIG. is a perspective schematic view of a filter according to an embodiment of the present invention;

[0022] Figure 5 FIG. is a frequency characteristic response diagram of a filter according to an embodiment of the present invention, generating a transmission zero at the low end of the passband;

[0023] Figure 6 FIG. is a frequency characteristic response diagram of a filter according to an embodiment of the present invention, generating a transmission zero at the high end of the passband;

[0024] Figure 7 Perspective schematic view of another filter according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0025] In order to make the objectives, technical solutions, and advantages of the present application clearer, the present invention will be further described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0026] It should be understood that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing this patent and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to this patent.

[0027] Figure 1 FIG. is an exploded structural schematic diagram of an electromagnetic hybrid coupling structure according to an embodiment of the present invention.

[0028] Referring to Figure 1 , an electromagnetic hybrid coupling structure according to an embodiment of the present invention includes: a dielectric plate 2, an electric coupling plate 3, a first coupling screw 4, a first metal arc plate 5, a second metal arc plate 6, and two resonators 7. The dielectric plate 2 is detachably disposed at the open end of the filter 1 through a connecting member. Wherein, metal layers 21 are respectively provided on two opposite wide surfaces of the dielectric plate 2. A coupling notch 22 is provided on the metal layer 21 close to the filter 1 side, and the electric coupling plate 3 is disposed in the coupling notch 22. The two ends of the electric coupling plate 3 are respectively connected to the first metal arc plate 5 and the second metal arc plate 6, thereby forming an integrated electric coupling structure. The first coupling screw 4 passes through the electric coupling plate 3 and enters the filter 1. Each resonator 7 is coaxially disposed with the first metal arc plate 5 or the second metal arc plate 6 in the filter 1, and the resonators 7 are connected by coupling connecting ribs 8 to form a magnetic coupling structure.

[0029] Figure 2 FIG. is an exploded structural schematic diagram of the dielectric plate according to an embodiment of the present invention, Figure 3 FIG. is a cross-sectional structural schematic diagram of an electromagnetic hybrid coupling structure according to an embodiment of the present invention.

[0030] Referring together to Figure 2 and Figure 3 , specifically, the first metal arc plate 5 and the second metal arc plate 6 are symmetrically distributed on the wide surface of the dielectric plate 2 with respect to the first coupling screw 4. This symmetrical design helps to ensure the uniformity of electromagnetic coupling. Further, to enhance the effect of electromagnetic coupling, the openings of the first metal arc plate 5 and the second metal arc plate 6 face each other, and the diameter of the first metal arc plate 5 is larger than the diameter of the resonator 7. A resonator cavity 71 is provided in each resonator 7, and there is a coupling interval between the open end of the resonator 7 and the coupling notch 22. Wherein the diameter of the resonator 7 is smaller than the diameter of the first metal arc plate 5 or the second metal arc plate 6. The first metal arc plate 5 and the second metal arc plate 6 are both open-circuit structures, and the electric coupling strength between the two resonators 7 can be adjusted by changing the diameter sizes of the first metal arc plate 5 and the second metal arc plate 6.

[0031] Furthermore, a plurality of mounting holes 23 for fixing the second coupling screw 9 are provided in the coupling notch 22, and the mounting holes 23 are symmetric about the first coupling screw 4. A protective layer formed by electroplating is provided on the outer peripheral surface of each resonator 7, which can prevent the resonator 7 from being affected by the external environment and improve its stability and reliability. The electric coupling plate 3 divides the coupling notch 22 into a left side portion and a right side portion, and the orthographic projection area of each resonator 7 on the dielectric plate 2 is smaller than the area of the left side portion or the right side portion. The end of the second coupling screw 9 enters the resonance cavity 71 of the resonator 7 through the mounting hole 23. During the design process of the filter 1, the magnetic coupling strength between the two resonators 7 can be changed by adjusting the depth of the second coupling screw 9 entering the resonance cavity 71. During the design process, the magnetic coupling strength between the two resonators 7 can also be further changed by changing the height of the coupling connecting rib 8.

[0032] Figure 4 FIG. is a perspective structural schematic diagram of a filter according to an embodiment of the present invention.

[0033] Referring to Figure 4 , another object of the present invention is to provide a filter 1, including: a base and a plurality of the above-mentioned electromagnetic hybrid coupling structures. Wherein, an open filtering cavity 12 is provided in the base, and both sides of the base are respectively connected to the connectors 13 to receive external signals. One side of each electromagnetic hybrid coupling structure is detachably connected to the open side of the base through a connecting member such as a screw, and the other side of each electromagnetic hybrid coupling structure is detachably connected to the bottom surface of the filtering cavity 12 through a connecting member such as a bolt. The sides of each electromagnetic hybrid coupling structure away from the filtering cavity 12 body are fixedly connected, and the sides of each electromagnetic hybrid coupling structure close to the filtering cavity 12 are fixedly connected through the coupling connecting rib 8, so as to form an integrated structure and close the filtering cavity 12.

[0034] In order to further illustrate the specific structure and advantages of the present application, the filter 1 with a single electromagnetic hybrid coupling structure and a plurality of electromagnetic hybrid coupling structures will be taken as examples for description respectively:

[0035] Figure 5 FIG. is a frequency characteristic response diagram of a filter according to an embodiment of the present invention that generates a transmission zero at the low end of the passband. Figure 6 FIG. is a frequency characteristic response diagram of a filter according to an embodiment of the present invention that generates a transmission zero at the high end of the passband.

[0036] Embodiment 1:

[0037] In this embodiment, there is only one electromagnetic hybrid coupling structure. After the dielectric plate 2 is fixed on the surface of the base by metal screws, the filtering cavity 12 is closed, and there are both an electric coupling path and a magnetic coupling path between the two resonators 7, that is, there are both electric coupling and magnetic coupling between the two resonators 7. Referring toFigure 5 When the electrical coupling amount and the magnetic coupling amount between the two resonators 7 are comparable, and the electrical coupling amount between the two resonators 7 is greater than the magnetic coupling amount, a transmission zero will be generated at a low frequency outside the passband of the filter 1. Refer to Figure 6 When the electrical coupling amount and the magnetic coupling amount between the two resonators 7 are comparable, and the magnetic coupling amount between the two resonators 7 is greater than the electrical coupling amount, a transmission zero will be generated at a high frequency outside the passband of the filter 1. Among them, the adjustment methods of the electrical coupling amount and the magnetic coupling amount have been described in detail above and will not be elaborated here.

[0038] Figure 7 Perspective structural schematic diagram of another filter according to an embodiment of the present invention.

[0039] Embodiment 2:

[0040] Refer to Figure 7 Differing from Embodiment 1, in this embodiment, there are two electromagnetic hybrid coupling structures. After the two electromagnetic hybrid coupling structures are installed in the base, a linear 4th-order coaxial cavity filter 1 is formed. In the design of the filter 1 in this embodiment, two electromagnetic hybrid coupling structure units are introduced, which can generate two transmission zeros. In other embodiments, there can be three, four, five or more integer numbers of electromagnetic hybrid coupling structures, and each electromagnetic hybrid coupling structure is respectively located in one path of the filter, which will not be further expanded and described here. In addition, the present invention can also be applied to filters with coaxial cavities including but not limited to linear coaxial cavity filters and cross-coupled coaxial cavity filters.

[0041] Another object of the present invention is to propose a multiplexer, including a plurality of the above-mentioned electromagnetic hybrid coupling structures. Each electromagnetic hybrid coupling structure is respectively located in a filter. Each port of the multiplexer is respectively provided with one path of the filter, and each path of the filter is respectively provided with a corresponding electromagnetic hybrid coupling structure. Among them, the multiplexer includes but is not limited to signal multiplexing devices with multiple ports such as duplexers, triplexers, and quadruplexers, and the specific number of ports is selected according to the performance requirements of the device.

[0042] In summary, in the present invention, by independently setting the electrical coupling structure and the magnetic coupling structure, during the debugging process, the electrical coupling strength and the magnetic coupling strength can be respectively adjusted by adjusting the dimensions and positions of the first coupling screw and the coupling connecting rod to complete the corresponding debugging.

[0043] The specific embodiments of the invention have been described above. Other embodiments are within the scope of the appended claims.

[0044] As used throughout this specification, the terms "exemplary", "example", etc. mean "serving as an example, instance, or illustration", and do not mean "preferred" or "advantageous" over other embodiments. For the purpose of providing an understanding of the described technology, the detailed description includes specific details. However, the technology may be practiced without these specific details. In some instances, well-known structures and devices are shown in block diagram form to avoid obscuring the concepts of the described embodiments.

[0045] The optional implementation manners of the embodiments of the present invention have been described in detail above in conjunction with the accompanying drawings. However, the embodiments of the present invention are not limited to the specific details in the above implementation manners. Within the scope of the technical concept of the embodiments of the present invention, various simple modifications can be made to the technical solutions of the embodiments of the present invention, and these simple modifications all fall within the protection scope of the embodiments of the present invention.

[0046] The above description of the content of this specification is provided to enable any ordinary person skilled in the art to implement or use the content of this specification. For those of ordinary skill in the art, various modifications to the content of this specification are obvious, and the general principles defined herein can also be applied to other variations without departing from the protection scope of the content of this specification. Therefore, the content of this specification is not limited to the examples and designs described herein, but is consistent with the broadest scope that conforms to the principles and novel features disclosed herein.

Claims

1. An electromagnetic hybrid coupling structure, arranged in a filter (1), characterized in that: include: A dielectric plate (2), an electric coupling plate (3), a first coupling screw (4), a first metal arc plate (5), a second metal arc plate (6) and two resonators (7); the dielectric plate (2) is detachably arranged at the open end of the filter (1); two opposite wide surfaces of the dielectric plate (2) are respectively provided with metal layers (21); a surface of the metal layer (21) close to the filter (1) is provided with a coupling notch (22); the electric coupling plate (3) is fixedly arranged in the coupling notch (22); two ends of the electric coupling plate (3) are respectively connected to the coupling notch (22); The first metal arc plate (5) and the second metal arc plate (6) are connected; one end of the first coupling screw (4) passes through the coupling notch (22) and enters the filter (1); the first metal arc plate (5) and the second metal arc plate (6) are symmetrically arranged about the first coupling screw (4); each resonator (7) is coaxially arranged with the first metal arc plate (5) or the second metal arc plate (6) in the filter (1), and the resonators (7) are connected to each other via coupling ribs (8) to form a magnetic coupling structure.

2. An electromagnetic hybrid coupling structure according to claim 1, characterized in that: The opening of the first metal arc plate (5) and the opening of the second metal arc plate (6) are arranged facing each other, and the diameter of the first metal arc plate (5) is greater than the diameter of the resonator (7).

3. An electromagnetic hybrid coupling structure according to claim 2, characterized in that: A resonant cavity (71) is provided in each resonator (7), and a coupling gap exists between the opening end of each resonator (7) and the coupling notch (22).

4. The electromagnetic hybrid coupling structure according to claim 3, characterized in that: A plurality of mounting holes (23) for fixing the second coupling screw rod (9) are arranged in the coupling notch (22), and each of the mounting holes (23) is symmetrical with respect to the first coupling screw rod (4).

5. The electromagnetic hybrid coupling structure according to claim 4, characterized in that: The outer peripheral surface of each resonator (7) is provided with a protective layer formed by electroplating.

6. The electromagnetic hybrid coupling structure according to claim 4, characterized in that: The electric coupling plate (3) separates the coupling notch (22) into a left side portion and a right side portion, and the orthographic projection area of ​​each resonator (7) on the dielectric plate (2) is smaller than the area of ​​the left side portion or the area of ​​the right side portion.

7. The electromagnetic hybrid coupling structure according to claim 6, characterized in that: A coupling gap exists between the electric coupling plate (3) and the metal layer (21).

8. A filter, characterized in that: include: A base (11) and a plurality of electromagnetic hybrid coupling structures as described in any one of claims 1 to 7; an open filter cavity (12) is provided in the base (11), one side of each of the electromagnetic hybrid coupling structures is detachably connected to the bottom surface of the filter cavity (12), and the other side of each of the electromagnetic hybrid coupling structures is detachably connected to the open end of the base (11); connectors (13) are respectively provided on both sides of the base (11), and each of the electromagnetic hybrid coupling structures is fixedly connected to each other to close the filter cavity (12).

9. A filter according to claim 8, characterized in that: Each of the electromagnetic hybrid coupling structures is arranged in sequence along the length direction of the base (11) in the filter cavity (12), and adjacent electromagnetic hybrid coupling structures are connected at one side close to the filter cavity (12) via the coupling ribs (8).

10. A multiplexer, characterized in that: The invention comprises a plurality of electromagnetic hybrid coupling structures as described in any one of claims 1 to 7.

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