CN212277366U

CN212277366U - Capacitive coupling structure and filter

Info

Publication number: CN212277366U
Application number: CN202021261993.5U
Authority: CN
Inventors: 何进军; 韦俊杰; 陈鹏
Original assignee: Chongqing Siruichuang Porcelain Electric Technology Co ltd
Current assignee: Chongqing Siruichuang Porcelain Electric Technology Co ltd
Priority date: 2020-06-30
Filing date: 2020-06-30
Publication date: 2021-01-01
Anticipated expiration: 2030-06-30

Abstract

The utility model relates to a technical field of communication equipment subassembly specifically is a capacitive coupling structure and wave filter, a capacitive coupling structure, include the intermediate part that links to each other with a plurality of adjacent and disconnected syntonizers, the intermediate part is including the connecting block that is used for connecting the syntonizer to and be used for keeping apart the chamber of syntonizer, and the electric field direction of two syntonizers of being connected with same intermediate part is different. A filter comprises a plurality of resonators, at least one capacitive coupling structure is used among the resonators, and the capacitive coupling structure enables capacitive negative coupling to be generated among the connected resonators. The capacitive coupling structure and the filter of this scheme of adoption can solve and adopt the technical problem that the capacitive negative coupling of deep loading frequency debugging blind hole realization leads to the resonance limit to produce among the prior art, realize the capacitive negative coupling through capacitive coupling structure, eliminate the resonance limit of low frequency, avoid the outband to restrain the range too high.

Description

Capacitive coupling structure and filter

Technical Field

The utility model relates to a technical field of communication equipment subassembly specifically is a capacitive coupling structure and wave filter.

Background

With the continuous development of the wireless base station communication technology, new requirements are put on the comprehensive performance and the volume of the filter, and the dielectric waveguide filter shows sufficient advantages in the comprehensive performance and the volume. With the development of multi-frequency systems, the requirements on the frequency selective characteristic and the out-of-band rejection characteristic of the filter are higher and higher, and the introduction of capacitive coupling is one of the methods for improving the frequency selective characteristic and the out-of-band rejection characteristic of the filter.

At present, a capacitive negative coupling mode is usually realized in a dielectric waveguide filter by arranging a deep blind hole negative coupling structure and loading coupling frequency through the deep blind hole negative coupling structure, so that the capacitive negative coupling is realized. For example, in a conventional dielectric waveguide filter, a dielectric body includes two resonators, a capacitive negative coupling hole is formed in the dielectric body between the two resonators, and a depth of the capacitive negative coupling hole is at least greater than half of a thickness of the dielectric body. The transmission path of the two resonators is changed by compressing the electric fields of the two resonators and is very close to the bottom surfaces of the resonators, so that negative coupling of a capacitance effect is formed. However, the essence of the dielectric waveguide filter is to provide a deep-loaded frequency tuning blind hole, which inevitably generates a resonance pole at the low end of the pass band of the dielectric waveguide filter, and on the premise of determining the zero position of the dielectric waveguide filter, the position of the resonance pole generally cannot be adjusted at will, so that the out-of-band rejection amplitude is too high, and the high rejection requirement of the wireless communication system is difficult to meet.

SUMMERY OF THE UTILITY MODEL

The utility model provides a capacitive coupling structure and wave filter to adopt dark loaded frequency debugging blind hole to realize that capacitive negative coupling leads to the technical problem that the resonance limit produced among the solution prior art.

The utility model provides one of the basic scheme is: a capacitive coupling structure comprises an intermediate part connected with a plurality of adjacent and unconnected resonators, wherein the intermediate part comprises a connecting block used for connecting the resonators and an isolating cavity used for isolating the resonators, and the electric field directions of the two resonators connected with the same intermediate part are different.

The basic scheme has the beneficial effects that: the arrangement of the middle part realizes the connection and the coupling of the two resonators, and a transmission path is constructed. The isolation part is arranged to separate the strong electromagnetic fields of the two resonators, and only the weak parts of the electromagnetic fields are kept to be connected with each other; because the middle electromagnetic field intensity and the edge electromagnetic field are weak, the coupling between the resonators can be very weak due to the integrated structure, and the coupling bandwidth is greatly reduced. The two resonators are connected through the middle part, the electric field directions of the two resonators connected with the same middle part are different, and capacitive cross coupling is formed through conversion among different resonance modes due to the difference of the electric field directions, so that the polarity of a transmission path of the filter is changed. According to the scheme, capacitive negative coupling is realized through the capacitive coupling structure, and a deep-loading frequency debugging blind hole is not required to be arranged, so that the problem that a resonance pole is generated at the lower end position of a pass band due to the fact that the capacitive negative coupling is realized through the deep-loading frequency debugging blind hole is solved.

Further, the connection block comprises a coupling window connected with the resonator and an isolation side connected with the isolation cavity, and the isolation side is covered with a conductive shielding layer. Has the advantages that: the conductive shielding layer can shield interference of external electromagnetic energy, and coupling of the resonator and the middle block is realized through the coupling window, so that crosstalk between the resonators is eliminated, and the suppression capability of far-end harmonic waves is improved.

Further, the connecting block is a component made of microwave dielectric materials. Has the advantages that: the microwave dielectric material has small volume, low microwave loss, small frequency temperature coefficient and high dielectric constant.

Further, the conductive shielding layer is a metal conductive shielding layer. Has the advantages that: compared with the conventional conductive shielding layer, the metal conductive shielding layer has better electromagnetic shielding effect.

The utility model provides a second of basic scheme: a filter comprises a plurality of resonators, and at least one capacitive coupling structure is used among the resonators.

The basic scheme has the beneficial effects that: by using the capacitive coupling structure, capacitive negative coupling is realized, and a deep-loading frequency debugging blind hole is not required to be arranged, so that a low-frequency resonance pole generated by realizing the capacitive negative coupling by adopting the deep-loading frequency debugging blind hole is eliminated. Meanwhile, the structure is simple, and the capacitive coupling structure is convenient to install and debug.

Further, the capacitive coupling structure enables capacitive negative coupling to be generated between the connected resonators. Has the advantages that: the low-frequency resonance pole is eliminated through the capacitive coupling structure, and the out-of-band rejection amplitude is prevented from being too high, so that the high rejection requirement of a wireless communication system is met.

And the input electrode structure and the output electrode structure are respectively arranged on the two resonators. Has the advantages that: the input electrode structure provides a port for input harmonics and the output electrode structure provides a port for output harmonics.

Furthermore, the device also comprises at least two debugging blind holes for adjusting the resonant frequency of the resonators, wherein the debugging blind holes are respectively positioned on different resonators. Has the advantages that: the resonant frequency of the resonator corresponding to the debugging blind hole is adjusted by adjusting the depth and the size of the debugging blind hole.

Further, a plurality of filters are all covered with a conductive shielding layer. Has the advantages that: the conductive shielding layer can shield the interference of external electromagnetic energy.

Drawings

Fig. 1 is a schematic structural diagram of a capacitive coupling structure according to a first embodiment of the present invention;

fig. 2 is a graph showing the variation of the coupling degree with the width of the coupling window according to the first embodiment of the capacitive coupling structure of the present invention;

fig. 3 is a schematic structural diagram of a second embodiment of the filter according to the present invention;

fig. 4 is a bottom view of a second embodiment of the filter of the present invention;

fig. 5 is a schematic structural diagram of a frequency tuning blind hole using deep loading according to a second embodiment of the present invention;

fig. 6 is a graph of the frequency response of the filter of fig. 4 according to the present invention;

fig. 7 is a frequency response graph of the filter of fig. 2 according to the present invention.

Detailed Description

The following is further detailed by way of specific embodiments:

example one

Reference numerals in the drawings of the specification include: the device comprises a first resonator 101, a second resonator 102, a connecting block 103 and a first debugging blind hole 104.

A capacitive coupling structure, as shown in fig. 1, includes intermediate portions connected to a plurality of adjacent and unconnected resonators, in this embodiment, the number of resonators is two, and the corresponding intermediate portions are one, and the two resonators are respectively defined as a first resonator 101 and a second resonator 102 for the sake of distinction.

The middle part comprises a connecting block 103 for connecting the resonators and an isolation cavity for isolating the resonators, and the electric field directions of the two resonators connected with the same middle part are different, in the embodiment, the first resonator 101 is arranged in a horizontal direction, and the second resonator 102 is arranged in a vertical direction, namely, the connecting block 103 is respectively connected with one end of the first resonator 101 and one side of the second resonator 102. The connecting block 103 is a component made of a microwave dielectric material, and in this embodiment, the middle portion is made of a ceramic material, and the same resonator is also made of a ceramic material.

The connection block 103 includes a coupling window connected to the two resonators, and an isolation side connected to the isolation cavity, where the isolation side is covered with a conductive shielding layer, and the conductive shielding layer is a metal conductive shielding layer, in this embodiment, the conductive shielding layer is made of silver. The shape of the coupling window may be rectangular, square, circular, and the like, in this embodiment, the shape of the coupling window is square, and similarly, the shape of the side surface of the connection block 103 where the coupling window is located may be rectangular, square, circular, and in this embodiment, the shape of the side surface of the connection block 103 where the coupling window is located is square, that is, the entire side surface of the connection block 103 where the coupling window is located is the coupling window.

The first resonator 101 is provided with a first tuning blind hole 104 along the electric field direction, and the resonant frequency of the first resonator 101 is adjusted by adjusting the depth, size or shape of the first tuning blind hole 104. The two resonators are connected through the capacitive coupling structure, and capacitive cross coupling is formed through conversion among different resonance modes due to different electric field directions of the two resonators, so that the polarity of a transmission path of the filter is changed, a resonance pole of low frequency is eliminated, and the out-of-band rejection amplitude is prevented from being too high.

When the capacitive coupling structure is used, the width and the height of the coupling window of the connecting block 103 can be adjusted according to filters with different bandwidth requirements, so that the coupling degree of the capacitive coupling structure is adjusted to adapt to different requirements. For example, in the embodiment, the thickness of the connecting block 103 is 1.5mm, and the magnitude of the coupling degree varies with the width of the coupling window under the condition that the height of the coupling window is fixed, and the variation curve is as shown in fig. 2.

Example two

A filter, as shown in fig. 3 and 4, includes a plurality of resonators, and at least one capacitive coupling structure 206 according to one embodiment is used between the resonators. In this embodiment, the number of resonators is five, four of which are arranged in the horizontal direction and the remaining one in the vertical direction. For the sake of distinction, resonators arranged in the vertical direction are defined as the first resonator 201, and resonators arranged in the horizontal direction are defined as the second to fifth resonators, respectively. In this embodiment, two capacitive coupling structures 206 are used, and are respectively disposed on two sides of the first resonator 201 for connecting with the third resonator 203 and the fourth resonator 204. The two capacitive coupling structures 206 enable capacitive negative coupling to be generated between the first resonator 201 and the third resonator 203, and capacitive negative coupling to be generated between the first resonator 201 and the fourth resonator 204.

The upper, lower, left, right, front and rear are defined in fig. 2, and the middle of the front side of the second resonator 202 is connected with a common coupling structure, and the front side of the common coupling structure is connected with the right end of the rear side of the third resonator 203. Fourth resonator 204 and fifth resonator 205 are connected to second resonator 202 and third resonator 203 in the same manner, and are symmetrically disposed on the right side of second resonator 202 and third resonator 203. The rear end of the right side of the second resonator 202 is connected with the rear end of the left side of the fifth resonator 205 through another common coupling structure, the middle of the right side of the third resonator 203 is connected with the capacitive coupling structure 206, the right side of the capacitive coupling structure 206 is connected with the middle of the lower left side of the first resonator 201, the two resonators are symmetrically arranged, the middle of the left side of the fourth resonator 204 is connected with another capacitive coupling structure 206, and the left side of the capacitive coupling structure 206 is connected with the middle of the lower right side of the first resonator 201.

During specific production, the positions and the structural dimensions of the second to fifth resonators and the common coupling structure are controlled by a mold for ceramic sintering, the second to fifth resonators and the common coupling structure are integrally formed, the dimension is refined and the surface is treated, a conductive material layer is attached to the surface, for example, a silver layer is coated on the surface, namely, the surface is plated with silver, an originally designed coupling window for coupling with the capacitive coupling structure 206 is formed on the conductive material layer, and finally, the capacitive coupling structure 206 is coupled and assembled with the capacitive coupling structure 206 which is also attached with the conductive material layer and is provided with the coupling window.

The centers of the tops of the second resonator to the fifth resonator are provided with debugging blind holes 207 for adjusting the resonant frequency of the resonators, the axial directions of the debugging blind holes 207 are the electric field directions of the resonators, and the number of the debugging blind holes 207 on the same resonator is one. By adjusting the depth, size or shape of the debugging blind hole 207, the center of the bottom of the second resonator 202 and the center of the bottom of the fifth resonator 205 are adjusted by adjusting the resonance frequency of the resonator where the debugging blind hole 207 is located, and an input electrode structure 208 and an output electrode structure 209 are respectively arranged, wherein the input electrode structure 208 and the output electrode structure 209 both comprise a coupling hole and a coupling ring, and the outer wall of the coupling ring is connected with the inner wall of the coupling hole.

The filter is covered with a conductive shielding layer, which includes the surface of the filter, the surface of the debugging blind hole 207, and the surfaces of the input electrode structure 208 and the output electrode structure 209, and the conductive shielding layer is a metal conductive shielding layer, in this embodiment, the conductive shielding layer is made of silver.

The filter structure using the deep loading frequency tuning blind hole 207 in the prior art to realize the capacitive negative coupling is schematically shown in fig. 5, and the frequency response graph thereof is shown in fig. 6. The horizontal axis in fig. 6 is the operating frequency in megahertz (MHz), and the vertical axis is the corresponding frequency of the dielectric waveguide filter in dB.

The frequency response graph using the filter in this embodiment is shown in fig. 7. In fig. 7, the horizontal axis represents the operating frequency in gigahertz (GHz), and the vertical axis represents the corresponding frequency of the dielectric waveguide filter in dB.

As can be seen from fig. 6 and fig. 7, in the prior art, a resonance pole is generated at the low end of the pass band (2250MHz), which results in an excessively high out-of-band rejection, and it is difficult to meet the high rejection requirement of the wireless communication system. And this scheme of adoption has introduced a transmission zero at the low end position of passband 3450-3550MHz, and it has verified the utility model provides a capacitive coupling structure 206's feasibility, simultaneously at passband low end position, there is not the production of parasitic capacitive negative coupling resonance limit to the not enough among the prior art has been solved.

The above description is only for the embodiments of the present invention, and the common general knowledge of the known specific structures and characteristics in the schemes is not described herein too much, and those skilled in the art will know all the common technical knowledge in the technical field of the present invention before the application date or the priority date, can know all the prior art in this field, and have the ability to apply the conventional experimental means before this date, and those skilled in the art can combine their own ability to perfect and implement the schemes, and some typical known structures or known methods should not become obstacles for those skilled in the art to implement the present application. It should be noted that, for those skilled in the art, without departing from the structure of the present invention, several modifications and improvements can be made, which should also be regarded as the protection scope of the present invention, and these will not affect the effect of the implementation of the present invention and the practicability of the patent. The scope of the claims of the present application shall be determined by the contents of the claims, and the description of the embodiments and the like in the specification shall be used to explain the contents of the claims.

Claims

1. A capacitive coupling structure, characterized by: the resonator comprises an intermediate part connected with a plurality of adjacent and unconnected resonators, wherein the intermediate part comprises a connecting block used for connecting the resonators and an isolating cavity used for isolating the resonators, and the directions of electric fields of the two resonators connected with the same intermediate part are different.

2. A capacitive coupling structure according to claim 1, wherein: the connecting block comprises a coupling window connected with the resonator and an isolation side connected with the isolation cavity, wherein the isolation side is covered with a conductive shielding layer.

3. A capacitive coupling structure according to claim 2, wherein: the connecting block is a component made of microwave dielectric materials.

4. A capacitive coupling structure according to claim 2, wherein: the conductive shielding layer is a metal conductive shielding layer.

5. A filter comprising a plurality of resonators, characterized in that: use of at least one capacitive coupling structure according to any of claims 1-4 between a plurality of resonators.

6. A filter according to claim 5, characterized in that: the capacitive coupling structure enables capacitive negative coupling between the resonators connected with the capacitive coupling structure.

7. A filter according to claim 5, characterized in that: the resonator further comprises an input electrode structure and an output electrode structure, wherein the input electrode structure and the output electrode structure are respectively arranged on the two resonators.

8. A filter according to claim 5, characterized in that: the device also comprises at least two debugging blind holes for adjusting the resonant frequency of the resonators, wherein the debugging blind holes are respectively positioned on different resonators.

9. A filter according to claim 5, characterized in that: a plurality of filters are each coated with a conductive shielding layer.

10. A filter according to claim 9, wherein: the conductive shielding layer is a metal conductive shielding layer.