CN116315544A

CN116315544A - Negative coupling structure of cavity filter

Info

Publication number: CN116315544A
Application number: CN202310281610.2A
Authority: CN
Inventors: 任雷斌; 庾波; 侯小强
Original assignee: Suzhou Rf Top Electronic Communications Co ltd
Current assignee: Suzhou Rf Top Electronic Communications Co ltd
Priority date: 2023-03-22
Filing date: 2023-03-22
Publication date: 2023-06-23

Abstract

The invention discloses a cavity filter negative coupling structure, which comprises a main body with a cavity, wherein the top of the main body is opened and communicated with the cavity, and a cover plate is covered at the opening of the cavity; the cavity is internally provided with a support column and a plurality of metal resonators, and the metal resonators are arranged around the periphery of the support column; an aluminum column is further arranged in the cavity, the aluminum column is located between the two metal resonators, and a tuning screw is arranged on the cover plate right above the aluminum column. The length of the tuning screw is used for converting magnetic coupling into electric coupling, two symmetrical transmission zero points can be generated at two ends of a pass band, the cost is reduced, the problem of complex assembly is also reduced, and the effect of easy control of the debugging zero points is achieved.

Description

Negative coupling structure of cavity filter

Technical Field

The invention relates to a cavity filter negative coupling structure, and belongs to the field of microwave communication.

Background

In a communication base station, a filter is an indispensable important component, and the design of a cavity filter in the current market is basically the same as that of the cavity filter. In the prior art, a window is formed between resonators in a cavity in the conventional filter shown in fig. 1, and a coupling flying rod is placed in the middle of the window to form negative coupling, so that the flying rod is required to be insulated from the cavity due to the negative coupling (structural capacitance), and meanwhile, the flying rod is required to be supported by a support made of an insulating material, so that the conventional filter for negative coupling has a complex structure, more required materials, labor consumption and high comprehensive cost.

Accordingly, there is a need for improvements in the art that overcome the shortcomings of the prior art.

Disclosure of Invention

The invention aims to provide a cavity filter negative coupling structure, which reduces assembly complexity and cost by generating transmission zero points at two ends of a passband.

The invention aims at realizing the following technical scheme:

the cavity filter negative coupling structure comprises a main body with a cavity, wherein the top of the main body is provided with an opening and is communicated with the cavity, and a cover plate is covered at the opening of the cavity; the cavity is internally provided with a support column and a plurality of metal resonators, and the metal resonators are arranged around the periphery of the support column; an aluminum column is further arranged in the cavity, the aluminum column is located between the two metal resonators, and a tuning screw is arranged on the cover plate right above the aluminum column.

Further, a plurality of the metal resonators are distributed in a square structure; the aluminum posts are disposed between two adjacent two metal resonators.

Further, a fixing screw is arranged on the cover plate, and the fixing screw corresponds to the metal resonator.

Furthermore, a plurality of nuts are fixedly arranged on the cover plate, and the fixing screws and the tuning screws are arranged on the corresponding nuts.

Further, the support columns are provided with inwards concave cambered surfaces, the number of the cambered surfaces corresponds to that of the metal resonators, and each metal resonator faces the corresponding cambered surface.

Furthermore, a plurality of bolt holes are formed in the edge of the cover plate, internal threaded holes corresponding to the bolt holes are formed in the main body, and the cover plate is locked with the main body through bolts.

Further, a silver plating layer is arranged on the surface of the tuning screw. The silver plating is attached to the surface of the tuning screw by electroplating.

By adopting the technical scheme, the method has the following beneficial effects: the magnetic field and the electric field between the metal resonators are converted by adjusting the relative positions of the tuning screw and the aluminum column, so that the magnetic coupling between the coupling cavities is converted into electric coupling, and for a CT model, the electric coupling can generate a transmission zero point at the lower end of a passband; for the CQ model, two symmetrical transmission zero points can be generated at two ends of a passband by electric coupling, and the structure of the invention not only reduces the cost, but also reduces the problem of complex assembly, thereby achieving the effect of easy control of the debugging zero point.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below. It will be apparent to those of ordinary skill in the art that the drawings in the following description are exemplary only and that other implementations can be obtained from the extensions of the drawings provided without inventive effort.

The structures, proportions, sizes, etc. shown in the present specification are shown only for the purposes of illustration and description, and are not intended to limit the scope of the invention, which is defined by the claims, so that any structural modifications, changes in proportions, or adjustments of sizes, which do not affect the efficacy or the achievement of the present invention, should fall within the ambit of the technical disclosure.

Fig. 1 is a diagram showing a structure of implementing negative coupling in a conventional filter.

Fig. 2 is a perspective view of the structure provided by the present invention.

Fig. 3 is a top view of fig. 2.

Fig. 4 is a cross-sectional view taken along the direction B-B in fig. 3.

Fig. 5 is a cross-sectional view taken along the direction C-C in fig. 3.

FIG. 6 is a graph of the results of a simulation analysis provided by the present invention.

Fig. 7 is a schematic diagram of a CT structure and a CQ structure provided by the present invention.

In the figure: 1. a main body; 2. a cover plate; 3. a support column; 4. a metal resonator; 5. an aluminum column; 6. a tuning screw; 7. a fixing screw; 8. and (3) a nut.

Detailed Description

The following describes the embodiments of the present invention further with reference to the drawings. The description of these embodiments is provided to assist understanding of the present invention, but is not intended to limit the present invention. In addition, the technical features of the embodiments of the present invention described below may be combined with each other as long as they do not collide with each other.

Examples

Referring to fig. 2-7, a cavity filter negative coupling structure comprises a main body 1 with a cavity, wherein the top of the main body 1 is opened and communicated with the cavity, and a cover plate 2 is arranged at the opening of the cavity in a covering way; the cavity is internally provided with a support column 3 and a plurality of metal resonators 4, and the metal resonators 4 are arranged around the periphery of the support column 3; an aluminum column 5 is further arranged in the cavity, the aluminum column 5 is located between the two metal resonators, and a tuning screw 6 is arranged on the cover plate 2 right above the aluminum column 5. The surface of the tuning screw 6 is provided with a silver coating. The silver plating is attached to the surface of the tuning screw by electroplating.

Specifically, the plurality of metal resonators 4 are distributed in a square structure as a whole, the aluminum posts 5 are arranged between two adjacent metal resonators, and the metal resonators 4 and the aluminum posts 5 form a square structure as a whole. As can be seen from fig. 2, the cover plate 2 is provided with seven fixing screws 7, and the fixing screws 7 are respectively located right above the metal resonator 4; the line connecting the central points of the seven said fixing screws and the central point of the tuning screw 6 forms a square. A plurality of nuts 8 are fixedly arranged on the cover plate 2, and the fixing screws 7 and the tuning screws 6 are arranged on the corresponding nuts 8. Wherein the fixing screw 7 is fixed without changing its position after being adjusted in place. In use, only the up and down positions of the tuning screw 6 need to be adjusted.

In this embodiment, the support columns 3 are provided with inward concave cambered surfaces, the number of the cambered surfaces corresponds to that of the metal resonators, and each metal resonator faces the corresponding cambered surface.

In this embodiment, the edge of the cover plate 2 is provided with a plurality of bolt holes, the main body 1 is provided with internal threaded holes corresponding to the bolt holes, and the cover plate 2 is locked with the main body 1 through bolts.

According to the invention, the relative positions of the tuning screw and the aluminum column are adjusted, so that the magnetic field and the electric field between the metal resonators are converted, the magnetic coupling between the coupling cavities is converted into electric coupling, and for a CT model, the electric coupling can generate a transmission zero point at the lower end of a passband; for the CQ model, the electrical coupling may create two symmetrical transmission zeros at both ends of the passband. The invention converts magnetic coupling into electric coupling through the length of the tuning screw, and can generate two symmetrical transmission zero points at two ends of a passband.

The embodiments of the present invention have been described in detail above with reference to the accompanying drawings, but the present invention is not limited to the described embodiments. It will be apparent to those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, and yet fall within the scope of the invention.

Claims

1. The cavity filter negative coupling structure is characterized by comprising a main body with a cavity, wherein the top of the main body is provided with an opening and is communicated with the cavity, and a cover plate is covered at the opening of the cavity; the cavity is internally provided with a support column and a plurality of metal resonators, and the metal resonators are arranged around the periphery of the support column; an aluminum column is further arranged in the cavity, the aluminum column is located between the two metal resonators, and a tuning screw is arranged on the cover plate right above the aluminum column.

2. The cavity filter negative coupling structure according to claim 1, wherein: the plurality of metal resonators are distributed in a square structure; the aluminum posts are disposed between two adjacent two metal resonators.

3. The cavity filter negative coupling structure according to claim 2, wherein: and the cover plate is provided with a fixing screw, and the fixing screw corresponds to the metal resonator.

4. A cavity filter negative coupling structure according to claim 3, characterized in that: the cover plate is fixedly provided with a plurality of nuts, and the fixing screws and the tuning screws are arranged on the corresponding nuts.

5. The cavity filter negative coupling structure according to claim 1, wherein: the support column is provided with inwards concave cambered surfaces, the number of the cambered surfaces corresponds to that of the metal resonators, and each metal resonator faces the corresponding cambered surface.

6. The cavity filter negative coupling structure according to claim 1, wherein: the edge of apron is provided with a plurality of bolt hole, be provided with on the main part and correspond the internal thread hole with the bolt hole, the apron with pass through the bolt lock solid between the main part.

7. The cavity filter negative coupling structure according to claim 1, wherein: the surface of the tuning screw is provided with a silver coating.