CN116632479A - Coaxial cavity resonator and filter - Google Patents

Abstract

The application provides a coaxial cavity resonator and a filter, which relate to the technical field of wireless communication related equipment, and comprise a shell component, a resonant rod component, a grounding piece and a tuning screw rod, wherein a resonant cavity is arranged in the shell component and is used for accommodating the resonant rod component and the grounding piece; the resonant rod assembly is connected with the shell assembly, and a first gap is formed between the resonant rod assembly and the shell assembly; the grounding piece is connected with the shell component, and a second gap is formed between the grounding piece and the resonant rod component; the tuning screw is connected with the resonant rod assembly and is used for fine tuning the frequency of the resonant rod assembly. The application relieves the technical problems of higher resonant frequency or larger volume of the coaxial cavity resonant disk adopting the flanging resonant rod in the prior art.

Description

Coaxial cavity resonator and filter

Technical Field

The application relates to the technical field of wireless communication related equipment, in particular to a coaxial cavity resonator and a filter.

Background

The resonant frequency of the resonator is mainly determined by two major factors, namely the volume and the dielectric constant of the resonator. The metal coaxial cavity filter has been widely used in radio frequency equipment in the fields of mobile communication, satellite communication, etc. for a long time due to its excellent filtering frequency selection performance, excellent heat dissipation, reliable stability, etc. The filling medium in the metal coaxial resonator is air with lower dielectric constant, and compared with the technology such as ceramic dielectric resonator, the filling medium has the prior disadvantages of reducing the resonant frequency, the volume of the resonator and the like. Therefore, how to reduce the volume and the frequency while maintaining the original performance advantages of the metal coaxial cavity filter is a long-standing topic in the field.

Existing methods of reducing the frequency or the volume of a metal coaxial cavity filter at a specific frequency can be roughly divided into two categories:

one is to increase the loading capacitance of the open end of the resonator. According to a capacitance formula C= (epsilon S)/(4 pi kd), wherein epsilon is a dielectric constant, S is the right area of a capacitor polar plate, d is the polar plate distance, the distance d is not affected by factors such as power capacity, machining assembly tolerance and the like, the distance d is not too small, at the moment, a mushroom umbrella-shaped loading disc is added at the open end of a quarter-wavelength coaxial resonant rod to increase the loading capacity of the resonant rod and a top cover plate so as to reduce the resonant frequency, but the size of the loading disc is increased, the section size of the resonator is also increased, the outer edge of the resonant disc is folded downwards later, the loading capacity formed by a flanging part and the side walls around the resonator is further reduced, and the situation that the resonant frequency is still frequently reduced due to insufficient capacitive loading, and the frequency adjustable range is beyond the machining precision and tolerance design is caused by further reducing the distance of the capacitor polar plate. In addition, in recent years, there are some schemes of filling high dielectric constant media such as ceramics between a resonant disk and a cover plate or adopting irregular resonant rods, cover plates and the like to increase the capacitive loading of the resonator, but the schemes are limited by the defects such as cost and reliability and cannot be popularized and applied.

The other is to change the TEM mode of the original metal coaxial resonator into TM mode by adopting a ceramic dielectric column or the like in the metal cavity so as to reduce the resonance frequency, and the scheme is also limited by the application range of the defects such as the realization cost, the reliability and the like.

Disclosure of Invention

The application aims to provide a coaxial cavity resonator and a filter, which are used for solving the technical problems of higher resonant frequency or larger volume of a coaxial cavity resonant disk adopting a flanging resonant rod in the prior art.

In order to achieve the above purpose, the application adopts the following technical scheme:

in a first aspect, the application provides a coaxial cavity resonator, which comprises a shell component, a resonant rod component, a grounding piece and a tuning screw, wherein a resonant cavity is arranged in the shell component and is used for accommodating the resonant rod component and the grounding piece;

the resonant rod assembly is connected with the shell assembly, and a first gap is formed between the resonant rod assembly and the shell assembly;

the grounding piece is connected with the shell component, and a second gap is formed between the grounding piece and the resonant rod component;

the tuning screw is connected with the resonant rod assembly and is used for fine tuning the frequency of the resonant rod assembly.

In an alternative embodiment of the present application, the resonant rod assembly includes a resonant disc and a resonant rod, the resonant disc is connected with the resonant rod, the first gap exists between the resonant disc and the housing assembly, and the second gap exists between the resonant disc and the grounding plate;

one end of the resonant rod, which is far away from the resonant disk, is connected with the shell component.

Further, the shell assembly comprises a shell body, a shielding cover plate and a resonant rod mounting column, wherein the shell body is connected with the shielding cover plate, and the shell body and the shielding cover plate form the resonant cavity;

the first gap exists between the shielding cover plate and the resonance disk;

the resonant rod mounting post is connected with the outer shell, and the resonant rod mounting post is connected with the resonant rod.

Further, the grounding piece is provided with a connecting piece, and the connecting piece is connected with the outer shell through a mounting piece.

In a second aspect, the present application provides a filter, including a coaxial cavity resonator according to any one of the foregoing embodiments, where the resonant cavity includes at least six subchambers, and each subchamber is provided with a corresponding resonant rod assembly;

the six subchambers are arranged in a row, and the subchambers positioned at one end of the row tail are communicated;

the resonant rod assemblies positioned adjacent to the same column are connected with the same grounding plate.

Further, the filter further comprises at least one coupling rib, and the coupling rib is arranged in the resonant cavity;

the coupling ribs are arranged between the adjacent resonant rod assemblies in the same column.

Further, the filter further comprises a coupling screw rod, and the coupling screw rod is arranged in the resonant cavity;

the coupling screw rods are arranged between the adjacent resonant rod assemblies in the same column.

In an alternative embodiment of the application, the sub-cavity at the head of the column is provided with an input/output connector, one end of the input/output connector penetrates out of the housing assembly, and the other end of the input/output connector is connected with the resonance rod assembly at the head of the column through a tap coupling piece.

In an alternative embodiment of the application, a coupling window is arranged between the subchambers positioned in the middle of the two rows of resonant cavities;

the capacitive flying rods are arranged between the coupling windows and are connected with the corresponding grounding plates through insulating pieces, and the capacitive flying rods are used for enabling two subchambers in the columns to generate cross capacitive coupling so as to generate transmission zero points.

Further, a notch is formed in the grounding piece and communicated with the inner ring of the grounding piece, and the notch is used for avoiding the capacitive flying rod so as to enhance capacitive cross coupling.

The application can realize the following beneficial effects:

in a first aspect, the application provides a coaxial cavity resonator, comprising a housing assembly, a resonant rod assembly, a grounding plate and a tuning screw, wherein a resonant cavity is arranged in the housing assembly and is used for accommodating the resonant rod assembly and the grounding plate; the resonant rod assembly is connected with the shell assembly, and a first gap is formed between the resonant rod assembly and the shell assembly; the grounding piece is connected with the shell component, and a second gap is formed between the grounding piece and the resonant rod component; the tuning screw is connected with the resonant rod assembly and is used for fine tuning the frequency of the resonant rod assembly.

In the application, the coaxial cavity resonator comprises a shell component, a resonant rod component, a grounding plate, a tuning screw rod and the like, wherein the resonant cavity is arranged in the shell component and is used for accommodating the resonant rod component and the grounding plate, and preferably, a threaded hole is arranged at the top of the shell component and is used for enabling the tuning screw rod to pass through and realizing fine tuning of the frequency of the resonant rod component; the resonant rod assembly penetrates through the inner ring of the grounding plate and is connected with the shell assembly, and the widths of a first gap and a second gap formed by the resonant rod assembly and the grounding plate after connection are approximately equal, so that capacitive loading is achieved on the upper side and the lower side of the resonant rod assembly at the same time, and the frequency of the resonator is greatly reduced.

Compared with the prior art, the coaxial cavity resonator provided by the application realizes the loading of upper and lower double-layer capacitors of the resonant rod assembly, and compared with the traditional flanging resonant rod, the coaxial cavity resonator has higher capacitor loading efficiency, and can realize lower resonant frequency and smaller resonator volume on the premise of the same plate-to-plate spacing; and more importantly, on the premise that the distance between the grounding plate and the top of the shell component is fixed, the plate distances of the upper layer and the lower layer of the resonant disk of the resonant rod component are equal, and the total loading capacitance is more stable, so that the processing precision and the assembly tolerance requirements of the resonant rod component are greatly reduced, and meanwhile, the sensitivity to the expansion coefficient of the resonant rod component material in a high-low temperature environment is correspondingly reduced, thereby not only bringing lower manufacturing cost of the resonant rod component, but also further reducing the plate distance of the resonant rod component limited by tolerance.

In conclusion, the application at least relieves the technical problems of higher resonant frequency or larger volume of the coaxial cavity resonant disk adopting the flanging resonant rod in the prior art.

In addition, a second aspect of the present application also provides a filter, including the coaxial cavity resonator provided in the first aspect; because the filter provided by the embodiment of the application comprises the coaxial cavity resonator provided by the first aspect, the filter provided by the embodiment of the application can achieve all the beneficial effects achieved by the coaxial cavity resonator provided by the first aspect.

Drawings

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings that are needed in the description of the embodiments or the prior art will be briefly described, and it is obvious that the drawings in the description below are some embodiments of the present application, and other drawings can be obtained according to the drawings without inventive effort for a person skilled in the art.

Fig. 1 is a schematic perspective view of a coaxial cavity resonator according to a first embodiment of the present application;

fig. 2 is a schematic top view of a coaxial cavity resonator according to a first embodiment of the present application;

fig. 3 is a schematic perspective view illustrating an internal structure of a coaxial cavity resonator according to a first embodiment of the present application;

fig. 4 is a schematic perspective view of internal components of a coaxial cavity resonator according to a first embodiment of the present application;

fig. 5 is a schematic cross-sectional structure of a coaxial cavity resonator according to a first embodiment of the present application;

fig. 6 is a schematic perspective view illustrating an internal structure of a filter according to a second embodiment of the present application;

fig. 7 is a schematic perspective view of internal components of a filter according to a second embodiment of the present application.

Icon: 1-a housing assembly; 11-an outer shell; 12-shielding cover plate; 13-a resonant rod mounting post; a 2-resonant rod assembly; 21-a resonant disk; 22-resonant rod; 3-grounding plate; 31-a connector; 4-mounting; 5-tuning a screw; a 6-tap coupling tab; 7-coupling a screw; 8-insulating member.

Detailed Description

For the purpose of making the objects, technical solutions and advantages of the embodiments of the present application more apparent, the technical solutions of the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application, and it is apparent that the described embodiments are some embodiments of the present application, but not all embodiments of the present application. The components of the embodiments of the present application generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations.

Thus, the following detailed description of the embodiments of the application, as presented in the figures, is not intended to limit the scope of the application, as claimed, but is merely representative of selected embodiments of the application. All other embodiments, which can be made by those skilled in the art based on the embodiments of the application without making any inventive effort, are intended to be within the scope of the application.

It should be noted that: like reference numerals and letters denote like items in the following figures, and thus once an item is defined in one figure, no further definition or explanation thereof is necessary in the following figures.

In the description of the present application, it should be noted that, directions or positional relationships indicated by terms such as "upper", "lower", "vertical", "horizontal", "inner", "outer", etc., are directions or positional relationships based on those shown in the drawings, or those that are conventionally put in place when the inventive product is used, are merely for convenience in describing the present application and simplifying the description, and do not indicate or imply that the apparatus or elements referred to must have a specific direction, be configured and operated in a specific direction, and thus should not be construed as limiting the present application. Furthermore, the terms "first," "second," "third," and the like are used merely to distinguish between descriptions and should not be construed as indicating or implying relative importance.

Furthermore, the terms "horizontal," "vertical," and the like do not denote a requirement that the component be absolutely horizontal or overhang, but rather may be slightly inclined. As "horizontal" merely means that its direction is more horizontal than "vertical", and does not mean that the structure must be perfectly horizontal, but may be slightly inclined.

In the description of the present application, it should also be noted that, unless explicitly specified and limited otherwise, the terms "disposed," "mounted," and "connected" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the above terms in the present application will be understood in specific cases by those of ordinary skill in the art.

Some embodiments of the present application are described in detail below with reference to the accompanying drawings. The following embodiments and features of the embodiments may be combined with each other without conflict.

Example 1

The embodiment provides a coaxial cavity resonator, referring to fig. 1 or 3, the coaxial cavity resonator comprises a housing assembly 1, a resonant rod assembly 2, a grounding plate 3 and a tuning screw 5, wherein a resonant cavity is arranged in the housing assembly 1 and is used for accommodating the resonant rod assembly 2 and the grounding plate 3; the resonance rod assembly 2 is connected with the shell assembly 1, and a first gap is formed between the resonance rod assembly 2 and the shell assembly 1; the grounding plate 3 is connected with the shell component 1, and a second gap is formed between the grounding plate 3 and the resonant rod component 2; a tuning screw 5 is connected to the resonating rod assembly 2, the tuning screw 5 being used to fine tune the frequency of the resonating rod assembly 2.

The embodiment of the application at least relieves the technical problems of higher resonant frequency or larger volume of the coaxial cavity resonant disk adopting the flanging resonant rod in the prior art.

In the embodiment of the application, the coaxial cavity resonator comprises a shell component 1, a resonant rod component 2, a grounding plate 3, a tuning screw 5 and the like, wherein a resonant cavity is arranged in the shell component 1 and is used for accommodating the resonant rod component 2 and the grounding plate 3, and preferably, a threaded hole is arranged at the top of the shell component 1 and is used for enabling the tuning screw 5 to pass through and realizing fine tuning of the frequency of the resonant rod component 2; the resonant rod assembly 2 passes through the inner ring of the grounding plate 3 and is connected with the shell assembly 1, and the widths of a first gap and a second gap formed by the connected resonant rod assembly 2 and the grounding plate 3 are approximately equal, so that capacitive loading is realized on the upper side and the lower side of the resonant rod assembly 2 at the same time, and the frequency of the resonator is greatly reduced.

Compared with the prior art, the coaxial cavity resonator provided by the embodiment of the application realizes the loading of the upper and lower double-layer capacitors of the resonant rod assembly 2, and compared with the traditional flanging resonant rod, the coaxial cavity resonator has higher capacitive loading efficiency, and can realize lower resonant frequency and smaller resonator volume on the premise of the same plate-to-plate spacing; and more importantly, on the premise that the distance between the grounding plate 3 and the top of the shell component 1 is fixed, the plate distances of the upper layer and the lower layer of the resonant disc 21 of the resonant rod component 2 are equal, and the total loading capacitance is more stable, so that the processing precision and the assembly tolerance requirements of the resonant rod component are greatly reduced, and meanwhile, the sensitivity to the expansion coefficient of the resonant rod component 2 material in a high-low temperature environment is correspondingly reduced, thereby not only bringing lower manufacturing cost of the resonant rod component 2, but also further reducing the plate distance of the resonant rod component 2 limited by the tolerance.

In an alternative implementation of this embodiment, referring to fig. 5, the resonant rod assembly 2 includes a resonant disc 21 and a resonant rod 22, the resonant disc 21 is connected to the resonant rod 22, a first gap exists between the resonant disc 21 and the housing assembly 1, and a second gap exists between the resonant disc 21 and the ground plate 3; the end of the resonant rod 22 remote from the resonant disk 21 is connected to the housing assembly 1.

Specific: the resonance plate 21 is connected to one end of the resonance rod 22, and preferably, the resonance rod 22 is connected to the bottom center of the resonance plate 21 in a direction perpendicular to the surface of the resonance plate 21. The first gap between the resonator plate 21 and the housing assembly 1 is substantially equal to the second gap between the resonator plate 21 and the ground plate 3; so that the capacitance of the capacitive loading above and below the resonator plate is maximized to achieve lower frequencies or smaller resonator volumes.

Further, referring to fig. 2 or 3, the housing assembly 1 includes a housing body 11, a shielding cover plate 12, and a resonant rod mounting post 13, the housing body 11 is connected to the shielding cover plate 12, and the housing body 11 and the shielding cover plate 12 form a resonant cavity; a first gap exists between the shield cover plate 12 and the resonance disk 21; the resonance lever mounting post 13 is connected to the outer case 11, and the resonance lever mounting post 13 is connected to the resonance lever 22.

Specific: the outer shell 11 is connected with the shielding cover plate 12 to form a resonant cavity, a threaded hole is formed in the shielding cover plate 12, the threaded hole is coaxially arranged with the resonant rod 22, and the threaded hole is in threaded connection with the tuning screw 5, so that the frequency of the resonator is further finely tuned by adjusting the depth of the tuning screw 5 from the shielding cover plate 12. The center of the inner bottom of the outer shell 11 is provided with a resonant rod mounting post 13, and the resonant rod mounting post 13 is provided with a threaded hole for connecting the resonant rod 22 to the resonant rod mounting post 13 in a threaded manner.

Further, referring to fig. 3 or 4, the ground plate 3 is provided with a connector 31, and the connector 31 is connected to the outer case 11 through the mount 4.

Specific: at least two connecting pieces 31 are oppositely arranged at the edge of the grounding piece 3, and through holes are formed in the connecting pieces 31 and are connected with the outer shell 11 through the mounting pieces 4; preferably, the mounting table of the outer shell 11 is provided with a threaded hole, and the mounting member 4 is preferably a bolt, that is, the grounding plate 3 is in threaded connection with the outer shell 11 through the bolt. And further, the grounding plate 3 is ring-shaped, the diameter of the opening of the inner ring is slightly larger than the outer diameter of the resonant rod 22, the diameter of the outer ring is approximately equal to the diameter of the resonant disc 21, two ends of the ring are respectively provided with a connecting piece 31 with holes, the positions of the connecting pieces correspond to the mounting tables of two opposite angles of the outer shell 11, the grounding plate 3 is fixed in the resonant cavity through screws, and the ring of the grounding plate 3 is coaxial with the resonant rod 22. The lower part of the resonant rod 22 passes through the inner ring of the grounding plate 3 and is fixed on the resonant rod mounting column 13 in the center of the resonant cavity through a screw.

Preferably, the user can adjust the loading capacitance between the resonator plate 21 and the ground plate 3 by changing the diameter of the inner and outer rings of the ground plate 3, thereby adjusting the resonant frequency of the resonator. The smaller the inner ring diameter of the grounding plate 3 is, the larger the outer ring diameter is, the larger the loading capacitance between the resonance disk 21 and the grounding plate 3 is, and the lower the resonance frequency is; conversely, the larger the diameter of the inner ring of the grounding plate 3, the smaller the diameter of the outer ring, and the smaller the loading capacitance between the resonant disk 21 and the grounding plate 3, the higher the resonant frequency.

When the resonator is used, on the premise that the distance between the grounding plate 3 and the top shielding cover plate 12 is fixed, the distance between the upper surface of the resonator plate 21 and the lower surface of the shielding cover plate 12 is reduced due to the influence of the height machining tolerance and flatness of the resonant rod 22, when the upper loading capacitance is increased, the distance between the lower surface of the resonator plate 21 and the upper surface of the grounding plate 3 is correspondingly increased, the lower loading capacitance is correspondingly reduced, and negative feedback adjustment is generated to keep the total capacitance loading amount of the resonator stable, and vice versa. Thus, the requirements of the resonator on the machining precision and tolerance of the shell component 1 and the resonant rod component 2 are reduced, and smaller space between design plates can be obtained under the same machining precision and tolerance requirements, so that the design frequency and volume of the resonator are further reduced.

Preferably, the number of the grounding points of the grounding plate 3 is not limited to two, the larger the number is, the better the grounding effect is, the higher the quality factor (Q value) of the corresponding resonator is, the more stable the mounting structure is, but the weight and the assembly time of the resonator are increased at the same time; however, it was found by testing that the balance of performance, ease of installation and structural stability was best when two diagonal ground points were employed. The grounding mode of the grounding plate is not limited to screw fixation, and other modes such as welding can be adopted. The grounding sheet 3 can be obtained by adopting a metal material through a stamping forming mode, a die or a machining forming mode, plastic and other materials through injection molding and the like, and then the grounding function is realized through a surface electroplating mode. An integrated circuit board (PCB) may also be used as the ground plate 3.

Preferably, the sensitivity of the double-layer capacitor-loaded metal coaxial cavity resonator provided by the embodiment of the application to the single-layer capacitor loading space is greatly reduced, so that the requirement on the thermal expansion coefficient of the resonant rod 22 is correspondingly reduced, the material selection range of the resonant rod 22 under the same frequency stability requirement is wider, and the material cost of the resonant rod 22 is lower or the availability of the material is higher, thereby reducing the cost of the whole resonator.

Preferably, the shell component 1, the resonant rod component 2 and the grounding piece 3 adopt a surface silver plating or copper plating mode to improve the surface conductivity, so as to improve the Q value of the resonator.

Furthermore, the resonator provided by the application can be provided with double cavities, namely, two resonant cavities are arranged in the shell component 1, the bottom center of each resonant cavity is respectively provided with a resonant rod mounting column 13, and a coupling rib is connected between the two resonant rod mounting columns 13; a grounding plate 3 is respectively fixed on the mounting table near the resonant cavity by three screws; the two resonant rod assemblies 2 are respectively arranged on the two resonant rod mounting posts 13 by screws and are respectively coaxially arranged with the grounding rings of the grounding plate 3; three threaded holes are formed in the shielding cover plate 12, two of the threaded holes are coaxially arranged with the resonant rods 22 and used for installing a screw rod to finely adjust the frequency of each resonant cavity, the other threaded hole is formed in the middle of the two resonant rod assemblies 2 and corresponds to the hollowed-out areas of the two grounding rings of the grounding plate 3 and used for installing the screw rod to finely adjust the coupling quantity of resonators on two sides.

Example two

The present embodiment provides a filter, referring to fig. 6 or fig. 7, including a coaxial cavity resonator provided by any of the alternative implementations of the first embodiment; the resonant cavity comprises at least six subchambers, and each subchamber is internally provided with a corresponding resonant rod assembly 2; every three of the six sub-cavities are in a row, and the sub-cavities positioned at one end of the row tail are communicated; adjacent resonant rod assemblies 2 in the same column are connected to the same ground plate 3.

Specific: the resonant cavity comprises at least six subchambers, namely six subchambers are arranged in the shell component 1, every three subchambers are arranged in a row, corresponding resonant rod components 2 are arranged in each subchamber, and the three resonant rod components 2 positioned in the same row are connected with the same grounding plate 3.

In an alternative implementation manner of this embodiment, the filter further includes at least one coupling rib, where the coupling rib is disposed in the resonant cavity; coupling ribs are arranged between adjacent resonant rod assemblies 2 in the same column.

Specific: coupling ribs are arranged between the adjacent resonant rod assemblies 2 in the same row, and preferably, tail cavities of the two rows of cavities are communicated with each other, and the coupling ribs are also arranged between the two cavities so as to be used for generating required coupling.

Further, the filter also comprises a coupling screw rod 7, and the coupling screw rod 7 is arranged in the resonant cavity; coupling screws 7 are arranged between the adjacent resonant rod assemblies 2 in the same column.

Specific: the coupling screw rod 7 is arranged in the resonant cavity; coupling screws 7 are arranged between the adjacent resonant rod assemblies 2 in the same column. And preferably, the tail cavities of the two rows of cavities are communicated with each other, and a coupling screw 7 is also arranged between the two cavities for generating the required coupling.

In an alternative implementation manner of this embodiment, the sub-cavity located at the head of the column is provided with an input/output connector, one end of the input/output connector penetrates out of the housing assembly 1, and the other end of the input/output connector is connected with the resonance rod assembly 2 of the head of the column through the tap coupling piece 6.

Specific: the first subchamber of each column is the input and output chamber of the filter, and comprises an input and output joint and a port tap coupling piece 6 for connecting the joint and the resonator.

In an alternative implementation manner of this embodiment, a coupling window is arranged between subchambers located in the middle of two rows of resonant cavities; and a capacitive flying rod is arranged between the coupling windows and is connected with the corresponding grounding piece 3 through an insulating piece 8, and the capacitive flying rod is used for generating cross capacitive coupling between two subchambers in the column so as to generate a transmission zero point.

Specific: a coupling window is also arranged between the two rows of intermediate cavities for communication, a capacitive flying rod is arranged between the coupling windows and is fixed through an insulating piece 8, and the coupling window is used for generating the required cross capacitive coupling between the two cavities so as to generate a transmission zero point.

Further, a notch is formed in the grounding piece 3 and communicated with the inner ring of the grounding piece 3, and the notch is used for avoiding the capacitive flying rod so as to enhance capacitive cross coupling.

Specific: the grounding piece 3 is provided with a notch communicated with the inner ring, and the notch is used for avoiding a capacitive flying rod arranged between the two rows of middle subchambers, so that capacitive cross coupling is enhanced.

Preferably, the frequency of the corresponding resonator can be adjusted by adjusting the inner diameter and the outer diameter of each grounding ring on the grounding plate 3; by adjusting the size and position of the connection segments on the grounding plate 3 for connecting adjacent grounding rings, a certain amount of adjustment can be made to the corresponding coupling amount.

Therefore, after the filter cavity mold is shaped, the design flaws of the cavity mold can be made up by optimizing the size of the grounding plate 3, so that the mold repair of the cavity mold is avoided, the fault tolerance of product design is improved, and even the filter products with different working frequency bands based on the same topological structure are developed or modified by utilizing the same cavity mold through matching with different grounding plates.

Preferably, the double-layer loading scheme provided by the application can be matched with a traditional flanging resonant rod. In order to avoid the flanging structure of the resonant rod assembly 2, the installation height of the grounding plate 3 needs to be correspondingly reduced. The ground ring is changed from a flat structure to a "grass cap" like structure protruding upward through the inner ring portion to increase the capacitive loading with the lower side of the resonator plate 21.

Compared with the double-cavity resonator with the traditional flanging resonant rod structure, the flanging structure of the resonant disc is omitted by the resonant rod, so that larger inductive coupling quantity between the resonators is realized, the height of the coupling ribs between the two resonant cavities can be reduced, and the negative influence of the coupling ribs on the Q value of the resonators is reduced. And the Q value performance in practical filter application is basically equivalent to that of the flanging resonant rod after the influence of the coupling ribs is considered, and the Q value of the application is better in application with wider passband and stronger coupling. And the coupling amount of the metal shell can be adjusted and optimized by changing the size of the connecting section on the grounding plate after the metal shell is opened and shaped, so that the die modification of the metal shell is avoided.

Finally, it should be noted that: in the present specification, each embodiment is described in a progressive manner, and each embodiment is mainly described by differences from other embodiments, and identical and similar parts between the embodiments are only required to be seen with each other; the above embodiments in the present specification are only for illustrating the technical solution of the present application, and are not limiting; although the application has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some or all of the technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit of the application.

Claims (10)

1. The coaxial cavity resonator is characterized by comprising a shell component (1), a resonant rod component (2), a grounding piece (3) and a tuning screw (5), wherein a resonant cavity is arranged in the shell component (1) and is used for accommodating the resonant rod component (2) and the grounding piece (3);

the resonant rod assembly (2) is connected with the shell assembly (1), and a first gap is formed between the resonant rod assembly (2) and the shell assembly (1);

the grounding piece (3) is connected with the shell component (1), and a second gap is formed between the grounding piece (3) and the resonant rod component (2);

the tuning screw (5) is connected with the resonant rod assembly (2), and the tuning screw (5) is used for fine tuning the frequency of the resonant rod assembly (2).

2. Coaxial cavity resonator according to claim 1, characterized in that the resonator rod assembly (2) comprises a resonator plate (21) and a resonator rod (22), the resonator plate (21) being connected to the resonator rod (22), the first gap being present between the resonator plate (21) and the housing assembly (1) and the second gap being present between the resonator plate (21) and the grounding plate (3);

the end of the resonant rod (22) remote from the resonant disk (21) is connected to the housing assembly (1).

3. Coaxial cavity resonator according to claim 2, characterized in that the outer housing assembly (1) comprises an outer housing (11), a shielding cover plate (12) and a resonator rod mounting post (13), the outer housing (11) being connected to the shielding cover plate (12) and the outer housing (11) and the shielding cover plate (12) forming the resonator cavity;

-said first gap is present between said shielding cover plate (12) and said resonator plate (21);

the resonant rod mounting post (13) is connected with the outer shell (11), and the resonant rod mounting post (13) is connected with the resonant rod (22).

4. A coaxial cavity resonator according to claim 3, characterized in that the grounding plate (3) is provided with a connection piece (31), which connection piece (31) is connected to the outer housing (11) by means of a mounting piece (4).

5. A filter comprising a coaxial cavity resonator according to any of claims 1 to 4, characterized in that the resonant cavity comprises at least six sub-cavities, each sub-cavity being provided with a respective resonant rod assembly (2);

the six subchambers are arranged in a row, and the subchambers positioned at one end of the row tail are communicated;

the adjacent resonant rod assemblies (2) positioned in the same row are connected with the same grounding piece (3).

6. The filter of claim 5, further comprising at least one coupling rib disposed within the resonant cavity;

the coupling ribs are arranged between the adjacent resonant rod assemblies (2) in the same row.

7. The filter according to claim 6, further comprising a coupling screw (7), the coupling screw (7) being provided within the resonant cavity;

the coupling screw rods (7) are arranged between the adjacent resonant rod assemblies (2) in the same row.

8. The filter according to claim 5, characterized in that the subchamber at the head of the column is provided with an input-output connector, one end of which penetrates out of the housing assembly (1) and the other end is connected with the resonant rod assembly (2) of the head of the column by means of a tap coupling piece (6).

9. The filter of claim 5, wherein a coupling window is provided between the subchambers in the middle of the two rows of resonant cavities;

the capacitive flying rods are arranged between the coupling windows and are connected with the corresponding grounding pieces (3) through insulating pieces (8), and the capacitive flying rods are used for enabling two subchambers in the columns to generate cross capacitive coupling so as to generate transmission zero points.

10. The filter according to claim 9, characterized in that the grounding plate (3) is provided with a notch, the notch is communicated with the inner ring of the grounding plate (3), and the notch is used for avoiding the capacitive flying rod so as to enhance capacitive cross coupling.