EP3985790A1

EP3985790A1 - Dielectric single cavity and dielectric waveguide filter

Info

Publication number: EP3985790A1
Application number: EP20833385.6A
Authority: EP
Inventors: Hong Zhou; Wei BU; Hongwei GONG; Feng Yang; Wanli YU; Ling Ding
Original assignee: ZTE Corp
Current assignee: ZTE Corp
Priority date: 2019-06-28
Filing date: 2020-05-09
Publication date: 2022-04-20
Also published as: CN112151924A; CN112151924B; EP3985790A4; WO2020259097A1

Abstract

The present disclosure provides a dielectric single cavity and a dielectric waveguide filter. The dielectric single cavity comprises: a dielectric single cavity body, comprising an outer housing and an inner housing provided in the outer housing, a cavity being formed between the outer housing and the inner housing, and the inner housing is provided with a metal coupling hole for inserting and coupling a PIN; and a first relief hole, the first relief hole being provided on the outer housing and surrounding the metal coupling hole.

Description

This application claims priority to Chinese patent application No. 201910578718.1 filed with the CNIPA on June 28, 2019 , disclosure of which is incorporated herein by reference in its entirety.

TECHNICAL FIELD

The present disclosure relates to the field of communication and, for example, to a dielectric single cavity and a dielectric waveguide filter.

BACKGROUND

The commercial demands for 5th-Generation (5G) Massive Multiple-Mn Multiple-Output (Massive MIMO) technologies are increasingly urgent, and as channels dramatically increases, the volume and weight of the base station system architecture need to be increased. However, considering the limitation of machining size of structural members and the difficulty of off-site construction, the volume, weight and cost of the base station system architecture cannot be increased linearly, and thus the requirements of miniaturization, light weight and low cost become increasingly urgent.
The filter, as a passive module of the base station system architecture, is used for selecting a communication signal frequency and filtering clutter or interference signals other than the communication signal frequency, and the size and weight of the filter directly affect the development of miniaturization and light weight of the base station system architecture. The dielectric waveguide filter replaces the air portion with a high dielectric constant dielectric material, plays roles of electromagnetic wave conduction and structure support, and also plays a role of electromagnetic shielding for surface metallization of a dielectric block, such that the volume and weight of a filter module can be obviously reduced. Meanwhile, the processing mode of the dielectric waveguide filter is different from the processing mode of the metal cavity filter. The dielectric waveguide filter is formed by sintering and die-casting powders, and the cost for production line change is much lower. In conclusion, the dielectric waveguide filter has become a trend of the passive filter module of the 5G base station system.
For the dielectric waveguide filter, if the conventional connector scheme is still adopted for input and output, the weight and volume advantages of the dielectric waveguide filter are weakened. For example, in the related art, the inner core coupling structure of the radio frequency connector of some dielectric waveguide filters is built in the input/output terminal of the dielectric waveguide filter. However, such a coupling structure is not simple enough, and will affect the design height, design direction and design size of the dielectric waveguide filter. The dielectric waveguide filter is still an independent module rather than a small component that can be mounted on a board. In addition, in other related art, although the dielectric waveguide filter can be implemented as a small component mountable on the board, the dielectric waveguide filter is only limited to be mounted in a microstrip line surface-mount assembly mode, and the signal shielding, the coupling range, the welding firmness and the high and low temperature stress cannot meet the market requirements.
Therefore, for the dielectric waveguide filter with small volume and light weight, there is no better solution for the problem in the related art that due to the adoption of the conventional connector scheme for the input and output, the weight and volume advantages of the dielectric waveguide filter are weakened.

SUMMARY

According to some embodiments of the present disclosure a dielectric single cavity and a dielectric waveguide filter is provided, to solve the problem in the related art that the advantages of the dielectric waveguide filter with small volume and light weight in weight and volume cannot be fully unleashed due to the adoption of the conventional connector scheme for input and output.
According to an embodiment of the present disclosure, a dielectric single cavity is provided. The dielectric single cavity may include: a dielectric single cavity body and a first avoidance hole. The dielectric single cavity body may include an outer housing, an inner housing arranged inside the outer housing, a cavity formed between the outer housing and the inner housing, and a metal coupling hole arranged on the inner housing. A coupling PIN is inserted in the metal coupling hole. The first avoidance hole is arranged on the outer housing and surrounding an outer side of the metal coupling hole.
According to another embodiment of the present disclosure, a dielectric waveguide filter is provided. The dielectric waveguide filter may include a filter dielectric block and one or more dielectric single cavities arranged inside the filter dielectric block. The dielectric single cavities are the dielectric single cavity described above.

BRIEF DESCRIPTION OF DRAWINGS

The drawings described herein are used to provide a further understanding of the present disclosure and form a part of the present disclosure. The embodiments and descriptions thereof in the present disclosure are used to explain the present disclosure and not to limit the present disclosure in any improper way. In the drawings:

FIG. 1 is a structural diagram illustrating a dielectric single cavity according to an embodiment of the present disclosure;
FIG. 2 is a cross-sectional view illustrating a dielectric single cavity according to an embodiment of the present disclosure;
FIG. 3 is a structural diagram illustrating a coupling PIN according to an embodiment of the present disclosure;
FIG. 4 is a structural diagram illustrating another coupling PIN according to an embodiment of the present disclosure;
FIG. 5 is a structural diagram illustrating a dielectric waveguide filter according to an embodiment of the present disclosure;
FIG. 6 is a structural diagram illustrating another dielectric waveguide filter according to an embodiment of the present disclosure;
FIG. 7 is a structural diagram illustrating a carrier according to an embodiment of the present disclosure;
FIG. 8 is a structural diagram illustrating another dielectric waveguide filter according to an embodiment of the present disclosure;
FIG. 9 is a structural diagram illustrating another carrier according to an embodiment of the present disclosure; and
FIG. 10 is a structural diagram illustrating another carrier according to an embodiment of the present disclosure.

DETAILED DESCRIPTION

The present disclosure will be described hereinafter in detail by the embodiments with reference to the drawings.
It is to be noted that, the terms "first", "second" and the like in the description, claims and drawings of the present disclosure are used to distinguish between similar objects and are not necessarily used to describe a particular order or sequence.

Embodiment I

In this embodiment a dielectric single cavity is provided. FIG. 1 is a structural diagram illustrating a dielectric single cavity according to the embodiment of the present disclosure. As shown in FIG. 1, the dielectric single cavity 1 includes a dielectric single cavity body 12 and a first avoidance hole 14. The dielectric single cavity body 12 includes an outer housing 122, an inner housing 124 arranged inside the outer housing 122, a cavity formed between the outer housing 122 and the inner housing 124, and a metal coupling hole 126 arranged on the inner housing 124 allowing a coupling PIN 2 to insert. The first avoidance hole 14 is arranged on the outer housing 122 and surrounds an outer side of the metal coupling hole 126.
In this embodiment, the first avoidance hole 14 is a through hole running through the outer housing 122, allowing the cavity of the dielectric single cavity body 12 to be in communication with the external environment. In another embodiment, the first avoidance hole 14 may not be a through hole, it is recessed to a certain depth and the interior of the cavity of the dielectric single cavity body 12 is not in communication with the external environment.
With the present disclosure, the conventional adopter connector as the input/output coupling is canceled, instead a metal coupling hole capable of allowing a coupling PIN to insert is arranged on the inner housing of the dielectric single cavity. The avoidance hole is arranged on an outer side of the metal coupling hole. Therefore, the problem in the related art that the dielectric waveguide filter with small volume and light weight cannot be fully used due to the adoption of the conventional connector scheme for input and output can be solved, and meanwhile the performance of the dielectric waveguide filter can be fully unleashed under the condition of reducing the size, weight and cost of the dielectric waveguide filter.
FIG. 2 is a cross-sectional view illustrating a dielectric single cavity according to an embodiment of the present disclosure. As shown in FIG. 2, the dielectric single cavity may include one or more first avoidance holes 14. When the dielectric single cavity includes only one first avoidance hole 14, the first avoidance hole 14 is a circular ring which surrounds the outer side of the metal coupling hole 126 and which is concentric with the metal coupling hole 126. When the dielectric single cavity includes a plurality of first avoidance holes 14, the first avoidance holes 14 are circular holes that are distributed on the outer side of the metal coupling hole 126, surrounding the metal coupling hole 126. These circular holes are in communication with each other. The arrangement of the multiple circular holes may be determined according to the number and size of the first avoidance holes 14.
In an embodiment, an outer surface of the outer housing 122 and an inner surface of the metal coupling hole 126 are covered by a metallized coating.
In the embodiment, the metallized coating may be silver coating, copper coating or copper-silver coating. In an embodiment, the metallized coating may be metallized coating of other metal materials for facilitating signal transmission.
In an embodiment, the metallized coating on the outer surface of the outer housing 122 and the metallized coating on the metallized coating on the inner surface of the metal coupling hole 126 may be the metallized coatings of the same metal material. Of course, in order to transmit different signals, the metallized coating on the outer surface of the outer housing 122 and the metallized coating on the metallized coating on the inner surface of the metal coupling hole 126 may be the metallized coatings of different metal materials.
FIG. 3 is a structural diagram illustrating a coupling PIN according to an embodiment of the present disclosure. As shown in FIG. 3, the coupling PIN 2 includes a plurality of elastic clamping legs 22 at intervals, during the assembling of the coupling PIN 2 into the metal coupling hole 126, the plurality of elastic clamping legs 22 are elastically deformed and approach to each other, such that the coupling PIN 2 is assembled into the metal coupling hole 126 by an interference fit.
In an embodiment, the coupling PIN 2 may have an elastic structure allowing the coupling PIN 2 to be assembled into the metal coupling hole 126 by an interference fit during the assembling of the coupling PIN 2 into the metal coupling hole 126, which will not be repeated herein. In an embodiment, the coupling PIN 2 may be fixed inside the metal coupling hole 126 by, for example, but is not limited to, welding.
In the embodiment, the coupling PIN 2 is a pin.
In the embodiment, with reference to FIG. 3, the coupling PIN 2 is cylindrical.
FIG. 4 is a structural diagram illustrating another coupling PIN according to an embodiment of the present disclosure. As shown in FIG. 4, the coupling PIN 2 has a cylindrical upper half part, and a disk-shaped half bottom part. In an embodiment, the upper half part of the coupling PIN needle 2 is a cylinder, and the half bottom part of the coupling PIN needle 2 is a square plate.
Optionally, the metal coupling hole 126, the coupling PIN 2 and the first avoidance hole 14 are coaxial.
By making the metal coupling hole 126, the coupling PIN needle 2 and the first avoidance hole 14 coaxial, a structure of the same function as the conventional connector is formed in the dielectric single cavity 1.
In the embodiment, if the number of the first avoidance holes 14 is more than one, "coaxial" refers to the axes of a circular ring formed by the plurality of first avoidance holes 14.
In an embodiment, according to the dielectric single cavity provided in the embodiments described above, the size of the metal coupling hole 126, the size of the coupling PIN 2 and the size of the first avoidance hole 14 can be adjusted to obtain a dielectric single cavity having suitable coupling signal energy.

Embodiment II

According to the embodiment further provided is a dielectric waveguide filter. The dielectric waveguide filter is used for implementing the above-mentioned embodiments and other embodiments. What has been described will not be repeated.
FIG. 5 is a structural diagram illustrating a dielectric waveguide filter according to an embodiment of the present disclosure. As shown in FIG. 5, the dielectric waveguide filter includes a filter dielectric block 3 and one or more dielectric single cavities 1 arranged inside the filter dielectric block 3.
It is to be noted that each of the dielectric single cavities 1 in the embodiment II is the dielectric single cavity described in the embodiment I.
In an embodiment, the filter dielectric block 3 is not only provided with the dielectric single cavities 1 mentioned in this embodiment, but also provided with dielectric single cavities corresponding to other filtering functions.
FIG. 6 is a structural diagram illustrating another dielectric waveguide filter according to an embodiment of the present disclosure. As shown in FIG. 6, one or more first debugging devices 32 are arranged inside the filter dielectric block 3. In this embodiment, each of the dielectric single cavities 1 is provided with one of the first debugging devices 32, and the first debugging devices 32 are configured to perform resonant frequency debugging on the dielectric single cavities 1.
In an embodiment, when a plurality of first debugging devices 32 are included, the dielectric waveguide filter further includes a second debugging device 34. The second debugging device 34 is configured between the dielectric single cavities 1 and configured to perform coupling debugging between the dielectric single cavities 1.
In an embodiment, the filter dielectric block 3 is covered with a metal film with backing adhesive.
In the embodiment, in use, for example, during a process of debugging using the first debugging device 32 and the second debugging device 34, it is likely that the metallized coating of the debugging devices described above will is damaged. In order to guarantee the shielding and grounding for the signal and to facilitate the surface mounting of suckers, the entire surface of the filter dielectric block 3 may be covered with a metal film (e.g., tin foil paper) with backing adhesive. Of course, for cost reduction, the metal film with backing adhesive can be applied only on the surfaces of the first debugging device 32 and the second debugging device 34, or regions near the first debugging device 32 and the second debugging device 34 on the surface of the filter dielectric block 3. In addition, the metal film must have the characteristic of not wrapping or falling off under high temperature for a long time.
FIG. 7 is a structural diagram illustrating a carrier according to an embodiment of the present disclosure. A shown in FIG. 7, the dielectric waveguide filter includes a carrier 4, which is connected to the dielectric single cavity 1. The carrier 4 includes a second avoidance hole 42, which runs through the carrier 4 and is configured to avoid the coupling PIN 2 and at least part of the first avoidance hole 14.
In the embodiment, the carrier 4 has a larger peripheral size greater than it of the dielectric waveguide filter. The material of the carrier 4 can be selected according to hardness, elasticity, expansion coefficient and heat dissipation requirements, and is usually the board material for the Printed Circuit Board (PCB). In an embodiment, the carrier 4 further includes two metal layers 44 and an internal layer 46. The two metal layers 44 covers a surface layer and a bottom layer of the carrier 4, respectively, and the internal layer 46 is arranged between the two metal layers 44.
In an embodiment, one of the metal layers 44 covering the surface layer of the carrier 4, and/or the internal layer 46 are configured to perform signal transmission. The coupling PIN 2 is connected to the one of the metal layers 44 covering the surface layer of the carrier 4 and/or the internal layer 46 which are configured to perform signal transmission.
In the embodiment, one of the metal layers 44 covering the bottom layer of the carrier 4 is used for welding and fixing the dielectric waveguide filter and strengthen grounding.
FIG. 8 is a structural diagram illustrating another dielectric waveguide filter according to an embodiment of the present disclosure. As shown in FIG. 8, the dielectric waveguide filter in FIG. 8 includes the carrier 4 arranged under the filter dielectric block 3. In addition, as it can be seen from FIG. 8 that, a plurality of open slots are formed on an outer side of the carrier 4 close to the filter dielectric block 3. Since the dielectric waveguide filter is at high temperature during the process of surface mounting, the difference of cold/heat shrinkage ratio between materials of the dielectric waveguide filter and the carrier 4 may cause stress. The stress can be released through the open slots, which effectively prevents the problem that the use of the dielectric filter may be affected by the fracture of the dielectric waveguide filter caused by the difference of cold/heat shrinkage ratio.
In an embodiment, the filter dielectric block 3 is placed on the carrier 4, the filter dielectric block 3 is crimped in place by means of a fixture and then is welded with carrier 4 in a welding device in which welding time and temperature have been set. In FIG. 8, a rear view shows the bottom of the carrier 4, including a plurality of ground holes arranged on the bottom layer and the second avoidance hole 42. In the embodiment, the second avoidance hole 42 may be metalized inside and to the bottom layer to form a closed peripheral shielding layer for the coupling PIN 2. In addition, the ground holes arranged between the input/output coupling PINs 2 may strengthen the input-output end isolation.
FIG. 9 is a structural diagram illustrating a carrier according to another embodiment of the present disclosure. As shown in FIG. 9, the length of the metal coupling PIN 2 is adjustable according to design requirements, and may be higher than it of the carrier 4. In this case, the coupling PIN 2 is engaged with the internal layer 46 via the hole in a soldering manner. In the embodiment, the internal layer 46 may be a signal layer inside the carrier 4, or an internal signal layer of a PCB board of another module of the base station system. The other module of the base station system may be, but not limited to, a power amplifier (PA) module or an antenna module.
FIG. 10 is a structural diagram illustrating another carrier according to an embodiment of the present disclosure. As shown in FIG. 10, a low-pass filter 5 is integrated on the carrier 4, which can suppress harmonic of remote ends of the dielectric waveguide filter. In FIG. 10, the low-pass filter 5 is located on the surface layer of the carrier 4 in a form of microstrip, and the low-pass filter 5 may also be arranged in the middle of the carrier 4, the implementation of which may vary according to scheme design requirements.
In one embodiment, the carrier 4 in the dielectric waveguide filter is not necessary. If other modules of the base station system do not have large size, and the high/low temperature deformation does not affect the welding requirements of the dielectric filter, the carrier 4 can be cancelled.

Claims

A dielectric single cavity, comprising:
a dielectric single cavity body, comprising an outer housing, an inner housing arranged inside the outer housing, a cavity formed between the outer housing and the inner housing, and a metal coupling hole arranged on the inner housing, into which a coupling PIN is inserted; and

a first avoidance hole, arranged on the outer housing and surrounding an outer side of the metal coupling hole.
The dielectric single cavity of claim 1, wherein an outer surface of the outer housing and an inner surface of the metal coupling hole are covered by metallized coating.
The dielectric single cavity of claim 1, wherein,
the coupling pin comprises a plurality of elastic clamping legs disposed at intervals, wherein during assembling of the coupling PIN into the metal coupling hole, the plurality of elastic clamping legs are elastically deformed and close to each other such that the coupling PIN is assembled inside the metal coupling hole by an interference fit;
or,

the coupling PIN is fixed inside the metal coupling hole.
The dielectric single cavity of claim 3, wherein the metal coupling hole, the coupling PIN and the first avoidance hole are coaxial.
A dielectric waveguide filter, comprising a filter dielectric block and at least one dielectric single cavity of one of claims 1 to 4, the at least one dielectric single cavity being arranged inside the filter dielectric block.
The dielectric waveguide filter of claim 5, further comprising a first debugging device, arranged on each dielectric single cavity and configured to perform resonant frequency debugging on the dielectric single cavity.
The dielectric waveguide filter of claim 6, comprising a plurality of dielectric single cavities, and a second debugging device arranged between the plurality of dielectric single cavities and configured to perform coupling debugging between the plurality of dielectric single cavities.
The dielectric waveguide filter of claim 5, further comprising a carrier connected to the dielectric single cavity and comprising:
a second avoidance hole, running through the carrier and configured to avoid the coupling PIN and at least part of the first avoidance hole.
The dielectric waveguide filter of claim 8, wherein the carrier further comprises:
two metal layers, covering a surface layer and a bottom layer of the carrier, respectively;
and

an internal layer, arranged between the two metal layers.
The dielectric waveguide filter of claim 9, wherein at least one of the metal layer covering the surface layer of the carrier and the internal layer is configured to perform signal transmission.
The dielectric waveguide filter of claim 10, wherein the coupling PIN is connected to the metal layer configured to perform signal transmission and covering the surface layer of the carrier, or the coupling PIN is connected to the internal layer configured to perform signal transmission, or the coupling PIN is connected to both the metal layer configured to perform signal transmission and covering the surface layer of the carrier and the internal layer configured to perform signal transmission.
The dielectric waveguide filter of claim 9, further comprising a low-pass filter integrated on the surface layer of the carrier or inside the carrier.