EP4322322A1

EP4322322A1 - Adapting apparatus, electronic device, terminal, and adapting apparatus manufacturing method

Info

Publication number: EP4322322A1
Application number: EP22783893.5A
Authority: EP
Inventors: Jie Peng; Jun Tao; Chuankang TANG
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2021-04-09
Filing date: 2022-03-25
Publication date: 2024-02-14
Also published as: CN115207588A; WO2022213826A1

Abstract

This application relates to the radio frequency field and provides a transition apparatus, an electronic device, a terminal, and a preparation method of the transition apparatus, for example, an antenna structure of a sensor like a radar, to resolve a connection problem between a microstrip line and a waveguide. The transition apparatus provided in this application includes a base board, a coupling cavity, and a resonant cavity. The base board has a through slot that penetrates through a first board surface and a second board surface, and an inner wall of the through slot is provided with a conducting layer. The coupling cavity is disposed on the first board surface of the base board, and the coupling cavity is coupled to a first end of the through slot. The waveguide may be coupled to a second end of the through slot, so that the coupling cavity and the waveguide may be coupled through the through slot. The resonant cavity is disposed on the first board surface of the base board, and the resonant cavity has at least one slit and a connecting end. The slit is coupled to the coupling cavity, and the connecting end of the resonant cavity is connected to the microstrip line. Through the through slot, an electromagnetic signal may be transmitted between the first board surface and the second board surface that are of the base board, and this implements a different-plane transmission effect.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to Chinese Patent Application No. 202110381645.4, filed with the China National Intellectual Property Administration on April 9, 2021 and entitled "TRANSITION APPARATUS, ELECTRONIC DEVICE, TERMINAL, AND PREPARATION METHOD OF TRANSITION APPARATUS", which is incorporated herein by reference in its entirety.

TECHNICAL FIELD

This application relates to the radio frequency field, and in particular, to a transition apparatus, an electronic device, a terminal, and a preparation method of a transition apparatus, for example, a radar and an antenna structure of the radar.

BACKGROUND

Compared with a conventional PCB (Printed Circuit Board) printed antenna, a waveguide antenna has obvious advantages in terms of low loss and high bandwidth, and therefore is easy to implement features such as high efficiency, long-distance coverage, and high range resolution. In addition, the waveguide antenna has a wider horizontal beam bandwidth, and can provide a larger field of view (Field of View) and widen a detection range. Therefore, the waveguide antenna is gradually widely used.
In an actual application of the waveguide antenna, the waveguide antenna needs to be connected to a device like a chip. However, because an outlet line of the device like the chip is generally a microstrip line, and an interface of the waveguide antenna is a standard waveguide structure, energy transmission cannot be directly performed. To implement signal transmission between the waveguide antenna and the device like the chip, a transition apparatus is required to bridge a waveguide and the microstrip line. A main function of the transition apparatus is to implement conversion of electromagnetic energy in different modes in the microstrip line and the waveguide, and reduce an energy loss in a process of energy conversion in different modes.
However, currently, no transition apparatus can implement efficient energy conversion and transmission.

SUMMARY

This application provides a transition apparatus that can effectively avoid energy leakage in a transmission process and implement efficient energy conversion and transmission, an electronic device, a terminal, and a preparation method of the transition apparatus.
According to one aspect, an embodiment of this application provides a transition apparatus, including a base board, a coupling cavity, and a resonant cavity. The base board has a first board surface and a second board surface, and the base board has a through slot that penetrates through the first board surface and the second board surface, and an inner wall of the through slot has a conducting layer, so that an electromagnetic signal can be efficiently transmitted in the through slot. The coupling cavity is disposed on the first board surface of the base board, where the coupling cavity is coupled to a first end of the through slot. A waveguide may be coupled to a second end of the through slot, so that the coupling cavity and the waveguide may be coupled through the through slot. A resonant cavity is disposed on the first board surface of the base board, where the resonant cavity has at least one slit and a connecting end. The slit is coupled to the coupling cavity, and the connecting end of the resonant cavity is connected to a microstrip line. It should be noted that the coupling represents effective transmission of an electromagnetic signal or energy between two components, but is not a limitation on a mechanical structure connection relationship between the two components. In an actual application, to implement coupling between the two components, a plurality of different types of manners may be used in a mechanical structure. In the transition apparatus provided in this embodiment of this application, the electromagnetic signal may be transmitted between the first board surface and the second board surface that are of the base board through the through slot, to implement a different-plane transmission effect. In addition, an extra insertion loss caused when the electromagnetic signal passes through the base board can be avoided, and this helps improve signal transmission efficiency. The resonant cavity is coupled to the coupling cavity through the slit, and this helps reduce an overall size of the transition apparatus. In addition, an electromagnetic signal in the resonant cavity can be efficiently transmitted to the coupling cavity. Alternatively, an electromagnetic signal in the coupling cavity can alternatively be efficiently transmitted to the resonant cavity, and this helps improve signal transmission efficiency.
In some implementations, the transition apparatus may further include a microstrip line disposed on the first board surface, the microstrip line may include a gradient transition structure, and the connecting end of the resonant cavity is connected to the microstrip line by using the gradient transition structure.
In some implementations, a structure of the coupling cavity may be a stepped structure with an opening toward the first board surface of the base board. A stepped structural design can effectively improve bandwidth of the coupling cavity, and stability of working performance can be ensured.
When the coupling cavity is fastened on the first board surface, an edge of the opening of the coupling cavity may be welded to the first board surface of the base board. Therefore, a connection effect between the coupling cavity and the base board is ensured, and energy leakage is prevented.
In addition, to ensure relative position precision between the coupling cavity and the base board, in a specific implementation, the coupling cavity may have a first positioning structure, where the first positioning structure is configured to position the coupling cavity at a target position of the base board.
In some implementations, a cross-sectional shape of the through slot may be the same as or similar to a cross-sectional shape of the waveguide, to prevent adverse effects such as insertion loss and impedance mismatch when a signal is propagated between the waveguide and the base board through slot. It should be noted herein that it is an ideal case that the foregoing shapes are the same. Based on specific product design and manufacturing, there may be a specific deviation between the cross-sectional shapes of the foregoing through slot and the waveguide, or a difference between the cross-sectional shapes of the foregoing through slot and the waveguide does not cause a great deviation in performance. Therefore, this application does not strictly pose a limitation that the foregoing cross-sectional shapes are completely the same, and the shapes may also be similar to each other or have a specific difference.
In some implementations, the resonant cavity may include a substrate integrated waveguide. A first end of the substrate integrated waveguide may include a connecting end, and an electric wall may be disposed at a second end of the substrate integrated waveguide, so that an electromagnetic signal in the integrated waveguide can be efficiently transmitted outward through the slit. The slit may be disposed on a surface that is of the substrate integrated waveguide and that faces away from the base board.
In a specific implementation, a length of the slit may be 0.5 λg, where λg is a wavelength of the electromagnetic wave propagating in a first medium. In an optional design, the first medium may be a base board, a resonant cavity, or air. It may be understood that, in a specific implementation, parameters such as a quantity, shapes, and sizes of slits may be properly set based on an actual situation. This is not limited in this application.
In some implementations, the transition apparatus may further include a waveguide. A flange may be disposed on an end face of a first end of the waveguide, and a top surface of the flange is attached to a second board surface of the base board. A structural design of the flange facilitates making the top surface of the flange into a plane with high flatness. Therefore, adhesion between the waveguide and the lower board surface of the base board 11 is improved, and an adverse situation like signal leakage is prevented.
In addition, to ensure positioning precision between the waveguide and the base board, a second positioning structure may be disposed in the waveguide, and a third positioning structure may be disposed on the second board surface of the base board. During assembly, the second positioning structure and the third positioning structure may cooperate with each other, to ensure a relative position between the waveguide and the base board. Finally, a fixed connection between the waveguide and the base board may be implemented by using a connection manner like welding, a screw, a buckle, or bonding.
According to another aspect, an embodiment of this application further provides an electronic device, including a chip and a waveguide antenna, and further including any one of the foregoing transition apparatuses. The chip may be connected to a connecting end of a resonant cavity by using a microstrip line, and the waveguide antenna may be connected to a second end of a through slot by using a waveguide.
In a specific application, the electronic device may alternatively be a radar, a base station, a detector, or the like. A specific type of the electronic device is not limited in this application.
According to another aspect, an embodiment of this application further provides a terminal, including the foregoing electronic device. The terminal may be an uncrewed aerial vehicle, a smart home, an intelligent manufacturing device, a surveying and mapping device, or the like. Application scopes of the transition apparatus and the electronic device provided with the transition apparatus are not limited in this application.
According to another aspect, an embodiment of this application further provides a preparation method, including: disposing a through slot in a base board having a first board surface and a second board surface, and disposing a conducting layer in an inner wall of the through slot, where a first end of the through slot penetrates through the first board surface, and a second end of the through slot penetrates through the second board surface. A coupling cavity is disposed on the first board surface, and the coupling cavity is coupled to the first end of the through slot. A resonant cavity is disposed on the first board surface. The resonant cavity has at least one slit and a connecting end, the slit is coupled to the coupling cavity, and the connecting end is connected to a microstrip line.
In a specific implementation, the method may further include: disposing the microstrip line on the first board surface. The microstrip line includes a gradient transition structure, and the connecting end is connected to the microstrip line by using the gradient transition structure.
In some implementations, the method may further include disposing a first positioning structure in the coupling cavity. The coupling cavity is positioned at a target position of the base board by using an auxiliary tooling, where the auxiliary tooling has a fastening structure configured to cooperate with the first positioning structure.
When the coupling cavity is fastened on the first board surface, the coupling cavity may be welded on the first board surface in a manner like surface mounting or laser beam welding, to implement a fixed connection between the coupling cavity and the base board.
In addition, the method may further include: attaching a top surface of a flange on an end face of a first end of a waveguide to the second board surface.
In some implementations, a second positioning structure may be disposed on the waveguide, and a third positioning structure may be disposed on the second board surface of the base board. The second positioning structure cooperates with the third positioning structure, to position the waveguide on the second board surface. Finally, a fixed connection between the waveguide and the base board may be implemented by using a welding process or by using fasteners such as a screw.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a schematic diagram of a perspective structure of a transition apparatus according to an embodiment of this application;
FIG. 2 is a schematic diagram of a cross-sectional structure of a transition apparatus according to an embodiment of this application;
FIG. 3 is a schematic diagram of a three-dimensional structure of a coupling cavity according to an embodiment of this application;
FIG. 4 is a schematic diagram of a cross-sectional structure of a coupling cavity according to an embodiment of this application;
FIG. 5 is a schematic diagram of a cross-sectional structure of another coupling cavity according to an embodiment of this application;
FIG. 6 is a schematic diagram of a plane structure of a base board according to an embodiment of this application;
FIG. 7 is a schematic diagram of a three-dimensional structure of a resonant cavity according to an embodiment of this application;
FIG. 8 is a schematic diagram of a three-dimensional structure of another resonant cavity according to an embodiment of this application;
FIG. 9 is a schematic diagram of another cross-sectional structure of a transition apparatus according to an embodiment of this application;
FIG. 10 is a schematic diagram of a three-dimensional structure of a waveguide according to an embodiment of this application;
FIG. 11 is a schematic diagram of a three-dimensional structure of a base board according to an embodiment of this application;
FIG. 12 is a schematic diagram of a structure of a waveguide according to an embodiment of this application;
FIG. 13 is a signal data simulation diagram of a transition apparatus according to an embodiment of this application;
FIG. 14 is an electric field strength distribution diagram of a transition apparatus according to an embodiment of this application;
FIG. 15 is a flowchart of a preparation method of a transition apparatus according to an embodiment of this application;
FIG. 16 is a flowchart of another preparation method of a transition apparatus according to an embodiment of this application; and
FIG. 17 is a schematic diagram of a cross-sectional structure of a radar according to an embodiment of this application.

DESCRIPTION OF EMBODIMENTS

To make objectives, technical solution, and advantages of this application clearer, the following further describes this application in detail with reference to the accompanying drawings.
To facilitate understanding of the transition apparatus provided in embodiments of this application, the following first describes an application scenario of the transition apparatus.
The transition apparatus provided in this application may be applied between a waveguide and a microstrip line, to implement an efficient connection between the waveguide and the microstrip line.
For example, vehicle-mounted antennas are usually provided in some vehicles. Currently, the vehicle-mounted antenna usually uses a conventional PCB (Printed circuit board) printed antenna. In an actual application, the PCB printed antenna may be connected to a device like a chip by using the microstrip line, to implement signal transmission. However, with continuous improvement of antenna performance requirements, the vehicle-mounted antenna gradually develops toward low loss, wide bandwidth, and large panel. Therefore, the conventional PCB printed antenna can no longer meet the requirements.
Compared with the PCB printed antenna, a waveguide antenna has obvious advantages in terms of low loss and wide bandwidth, and the waveguide antenna is gradually widely used.
However, in an actual application, a signal transmission structure of the waveguide antenna is generally the waveguide, and a signal transmission structure of the device like the chip is generally the microstrip line. Therefore, the waveguide antenna (or the waveguide) and the chip (or the microstrip line) need to be connected by using a corresponding transition apparatus, to implement efficient signal transmission. However, the current transition apparatus still has many shortcomings, and it is difficult to achieve a different-plane transmission effect, so that efficient signal conversion and transmission cannot be implemented.
Therefore, this application provides a transition apparatus that can effectively avoid signal leakage in a transmission process and implement efficient signal conversion and transmission.
To make objectives, technical solution, and advantages of this application clearer, the following further describes this application in detail with reference to the accompanying drawings and specific embodiments.
Terms used in the following embodiments are merely intended to describe specific embodiments, but are not intended to limit this application. As used in the specification of this application and the appended claims, the singular expression "a/an", "the", "the foregoing", "such a", or "this" is intended to also include "one or more" expression unless otherwise clearly indicated in the context. It should be further understood that in the following embodiments of this application, "at least one" and "one or more" mean one, two or more than two. The term"and/or" describes an association relationship between associated objects, and indicates that three relationships may exist. For example, A and/or B may indicate the following cases: Only A exists, both A and B exist, and only B exists, where A and B may be singular or plural. The character "/" generally indicates an "or" relationship between the associated objects.
References to "one embodiment" or "some embodiments" or the like described in this specification mean that one or more embodiments of this application include a specific feature, structure, or feature described with reference to the embodiment. Therefore, statements such as "in an embodiment", "in some embodiments", "in some other embodiments", and "in other embodiments" that appear at different places in this specification do not necessarily mean referring to a same embodiment. Instead, the statements mean "one or more but not all of embodiments", unless otherwise specifically emphasized in another manner. The terms "include", "have", and their variants all mean "include but are not limited to", unless otherwise specifically emphasized in another manner.
In a transition apparatus provided in this application, the transition apparatus may include: a base board that has a first board surface and a second board surface, the base board has a through slot, a first end of the through slot penetrates through the first board surface, a second end of the through slot penetrates through the second board surface, and an inner wall of the through slot has a conducting layer; a coupling cavity, disposed on the first board surface, and coupled to the first end of the through slot; and a resonant cavity, disposed on the first board surface, where the resonant cavity has at least one slit and a connecting end, the slit is coupled to the coupling cavity, and the connecting end is connected to a microstrip line.
Specifically, as shown in FIG. 1 and FIG. 2, in an embodiment provided in this application, a transition apparatus 10 includes a base board 11, a coupling cavity 12, and a resonant cavity 13. The base board 11 has a first board surface (an upper board surface in the figure) and a second board surface (a lower board surface in the figure). In addition, the base board 11 has a through slot 111 that penetrates through the first board surface and the second board surface, and an inner wall of the through slot 111 has a conducting layer (which is not shown in the figure), so that an electromagnetic signal can be efficiently transmitted in the through slot 11. The coupling cavity 12 is disposed on the upper board surface of the base board 11, and the coupling cavity 12 is coupled to an upper end of the through slot 111. A waveguide 01 may be coupled to a lower end of the through slot 111, so that the coupling cavity 12 and the waveguide 01 may be coupled through the through slot 111. The resonant cavity 13 is disposed on the upper board surface of the base board 11, and the resonant cavity 13 has a slit 131 and a connecting end (which is not shown in the figure). The slit 131 is coupled to the coupling cavity 12, and the connecting end of the resonant cavity 13 is connected to a microstrip line 02 by using a gradient transition structure 021. It should be noted that the coupling represents effective transmission of an electromagnetic signal or energy between two components, but is not a limitation on a mechanical structure connection relationship between the two components. In an actual application, to implement coupling between the two components, a plurality of different types of manners may be used in a mechanical structure.
In the transition apparatus 10 provided in this embodiment of this application, the electromagnetic signal may be transmitted between the upper board surface and the lower board surface that are of the base board 11 through the through slot 111, to implement a different-plane transmission effect. In addition, an extra insertion loss caused when the electromagnetic signal passes through the base board 11 can be avoided, and this helps improve signal transmission efficiency. The resonant cavity 13 is coupled to the coupling cavity 12 through the slit 131, and this helps reduce an overall size of the transition apparatus 10. In addition, an electromagnetic signal in the resonant cavity 13 can be efficiently transmitted to the coupling cavity 12. Alternatively, an electromagnetic signal in the coupling cavity 12 may alternatively be efficiently transmitted to the resonant cavity 13. This helps improve signal transmission efficiency.
Specifically, the transition apparatus 10 may further include the microstrip line 02 disposed on the first board surface, and the microstrip line 02 may include the gradient transition structure 021. The connecting end of the resonant cavity 13 is connected to the microstrip line 02 by using the gradient transition structure 021.
To facilitate understanding of the technical solutions in this application, the following first describes in detail a signal processing procedure.
Still refer to FIG. 1 and FIG. 2. When a signal is transmitted from the microstrip line 02 to the waveguide 01, an electrical signal in the microstrip line 02 may perform conversion by using the gradient transition structure 021. For example, a quasi-TEM wave (Transverse Electromagnetic Wave) in the microstrip line 02 may be converted into a TE wave (Transverse Electric Wave) that can be transmitted in the resonant cavity 13 by using the gradient transition structure 021. The TE wave propagates in the resonant cavity 13, and is coupled to the coupling cavity 12 through the slit 131. The coupling cavity 12 is excited by the slit 131 to resonate, and converts energy into a TE₁₀ wave. The coupling cavity 12 is coupled to the upper end of the through slot 111, and the lower end of the through slot 111 is coupled to the waveguide 01. Therefore, the TE₁₀ wave can be transmitted to the waveguide 01 through the through slot 111. Therefore, entire energy transmission from the microstrip line 02 to the waveguide 01 is implemented. The TEM wave refers to an electromagnetic wave whose electric field and magnetic field of the electromagnetic wave are both on a plane perpendicular to a propagation direction. The TE wave refers to an electromagnetic wave whose electric field vector is perpendicular to the propagation direction, and components of a magnetic field vector are both perpendicular to the propagation direction and parallel to the propagation direction. The TE₁₀ wave refers to an electromagnetic wave in a standard waveguide that has a magnetic field component but no electric field component along the propagation direction.
It may be understood that, when a signal is transmitted from the waveguide 01 to the microstrip line 02, an entire signal transmission process is opposite to the foregoing. Details are not described herein again.
In a specific implementation, the base board 11 may be a printed circuit board (Printed circuit board, PCB) or a flexible printed circuit (Flexible printed circuit, FPC), or may be another type of board structure. The base board 11 may be a single-layer board or a multi-layer board. A specific type, a quantity of layers, and a shape of the base board 11 are not limited in this application. It may be understood that, when the base board 11 is the multi-layer board, the first board surface refers to an upper board surface of a board body located at an uppermost layer, and the second board surface refers to a lower board surface of a board body located at a lowermost layer.
In a specific application, the microstrip line 02 may be an independent line structure.
Alternatively, as shown in FIG. 1, the microstrip line 02 may be directly formed on the upper board surface of the base board 11 by using a process like coating or etching. In addition, in this embodiment provided in this application, to improve a transmission effect of the electrical signal in the microstrip line 02, and prevent from adverse effects such as electromagnetic interference, in a length direction of the microstrip line 02, rows of metal through holes 022 are disposed on both sides of the microstrip line 02. It may be understood that, in another implementation, the metal through hole 022 may alternatively be replaced with a structural form similar to the microstrip line, or a setting is omitted. This is not limited in this application.
In addition, in a specific implementation, specific structure types of the coupling cavity 12 may alternatively be diversified.
For example, as shown in FIG. 3 and FIG. 4, in an embodiment provided in this application, a structure of the coupling cavity 12 is a stepped structure with an opening toward the base board, for example, an opening toward a first board surface of a base board 11.
Specifically, the coupling cavity 12 includes a front cavity 121 and a dorsal cavity 122. The front cavity 121 includes a first cavity 1211 and a second cavity 1212 that are of different heights. A height of the first cavity 1211 is slightly greater than a height of the second cavity 1212. In the coupling cavity 12 provided in this application, a stepped structural design can effectively improve bandwidth of the coupling cavity 12, and stability of working performance can be ensured.
It may be understood that, in another implementation, the coupling cavity 12 may alternatively be a non-stepped structure.
For example, as shown in FIG. 5, in another embodiment provided in this application, a cavity of the coupling cavity 12 is rectangular. Certainly, in another implementation, the cavity of the coupling cavity 12 may alternatively be a structure of another shape, like an ellipse or a circle. A specific shape of the coupling cavity 12 is not limited in this application.
In addition, as shown in FIG. 2, when the coupling cavity 12 is mounted on the base board 11, to improve relative position precision between the coupling cavity 12 and the base board 11, the coupling cavity 12 may be provided with a first positioning structure 123. During assembly, an auxiliary tooling (which is not shown in the figure) may be used to position the coupling cavity 12, to accurately mount the coupling cavity 12 at a target position of the base board 11. Subsequently, the coupling cavity 12 may be fastened on the upper board surface of the base board 11 by using a welding (for example, surface mounting or laser beam welding) process, to implement a fixed connection between the coupling cavity 12 and the base board 11.
Specifically, as shown in FIG. 2, in the embodiment provided in this application, the first positioning structure 123 includes a positioning hole. The auxiliary tooling (which is not shown in the figure) may include a positioning post.
In a specific implementation, a cross section of the positioning hole may be a circular, ellipse, rectangular, or another polygon structure. Correspondingly, a cross section of the positioning post may be a circular, ellipse, rectangular, or another polygon structure.
In addition, the positioning hole and the positioning post may be adapted in a gap fit manner. To be specific, after the positioning post is inserted into the positioning hole, a specific gap can be maintained between the positioning post and the positioning hole, so that the positioning post can be smoothly inserted into the positioning hole. In addition, after the coupling cavity 12 is fixedly mounted on the base board 11, it is also convenient to disassemble the auxiliary tooling. Alternatively, the positioning post and the positioning hole may be adapted in an interference fit manner. To be specific, after the positioning post is inserted into the positioning hole, close matching may be implemented between the positioning post and the positioning hole, to prevent loosening between the positioning post and the positioning hole. This can improve stability between the coupling cavity 12 and the auxiliary tooling.
During specific disposition, one or more positioning holes and positioning posts may be disposed. For example, a quantity of disposed positioning posts may be two. Correspondingly, a quantity of disposed positioning holes may alternatively be two. By using a plurality of positioning posts and positioning holes, a relative position between the coupling cavity and the auxiliary tooling can be effectively raised, so that the coupling cavity 12 can be more accurately mounted on the base board 11. During specific disposition, the quantity of disposed positioning posts may be consistent with the quantity of disposed positioning holes. That is, one positioning post is correspondingly adapted to a corresponding positioning hole.
In addition, when the coupling cavity 12 is fastened on the base board 11, the coupling cavity 12 may be fixedly connected to the base board 11 through welding.
For example, the coupling cavity 12 may be welded to the upper board surface of the base board 11 by using a surface mounting process.
Refer to FIG. 2 and FIG. 3. Specifically, an edge 120 of the opening of the coupling cavity 12 may be welded to the upper board surface of the base board 11. In a specific implementation, a thickness of the edge 120 of the opening of the coupling cavity 12 may be reduced as much as possible, to effectively reduce a welding area between the coupling cavity 12 and the base board 11. Therefore, problems such as warpage of the base board 11 caused by large- area welding can be avoided. In addition, a problem caused by a processing error can be reduced to a specific extent.
It may be understood that, in another implementation, the coupling cavity 12 and the base board 11 may alternatively be fixedly connected in another manner. For example, the coupling cavity 12 and the base board 11 may be fixedly connected in a connection manner like welding, screwing, buckling, or bonding. A fixed connection manner between the coupling cavity 12 and the base board 11 is not limited in this application.
When the resonant cavity 13 is specifically disposed, specific types and structures of the resonant cavity 13 may alternatively be diversified.
For example, as shown in FIG. 6, in an embodiment provided in this application, the resonant cavity 13 includes a substrate integrated waveguide (Substrate integrated waveguide, SIW).
Specifically, as shown in FIG. 7, the substrate integrated waveguide is a structure in a form of a microwave transmission line, and a field propagation mode of a waveguide is implemented on a dielectric substrate by using a metal through hole. Structurally, the substrate integrated waveguide mainly includes a dielectric substrate 132, an upper metal layer 133 is disposed on an upper board surface of the dielectric substrate 132, and a lower metal layer 134 is disposed on a lower board surface of the dielectric substrate 132. A plurality of metal through holes 135 are disposed in rows in the dielectric substrate 132, and penetrates through the upper metal layer 133 and the lower metal layer 134. In addition, to enable an electromagnetic wave in the substrate integrated waveguide to be coupled to a coupling cavity through a slit 131, an electric wall 136 is disposed at one end (a left end in the figure) of the substrate integrated waveguide. The electric wall 136 can effectively block the electromagnetic wave in the integrated waveguide, so that the electromagnetic wave can be coupled to the coupling cavity through the slit 131.
In the embodiment provided in this application, the electric wall 136 is formed by a row of metal through holes arranged at intervals. It may be understood that, in another implementation, the electric wall 136 may alternatively be formed by a metal piece embedded in the dielectric substrate 132 or a metal layer disposed at a left end of the dielectric substrate 132. A manner of disposing the electric wall 136 is not limited in this application.
The dielectric substrate 132 may be a component of a base board 11. For example, when the base board 11 is a multilayer board, the dielectric substrate 132 may be a board structure located at an uppermost layer of the base board 11. Alternatively, the substrate integrated waveguide may be an independent, and finally is fastened on an upper board surface of the base board 11 by using a surface-mounting process or the like. In a specific application, the substrate integrated waveguide and the base board 11 may be an integrated structure, or may be a split structure. This is not specifically limited in this application.
In a specific application, the slit 131 may be provided on a surface that is of the resonant cavity 13 and that is away from the base board 11.
Specifically, as shown in FIG. 7, the slit 131 may be provided on a surface of the upper metal layer 133, and the slit 131 penetrates through a thickness of the upper metal layer 133, so that an electromagnetic signal of the resonant cavity 13 can be transmitted outward through the slit.
Please refer to FIG. 2. In an actual application, the coupling cavity 12 is alternatively disposed on the upper board surface of the base board 11. Therefore, to efficiently transmit an electromagnetic signal transmitted from the slit 131 to the coupling cavity 12, the slit 131 may be provided on the surface that is of the resonant cavity 13 and that is away from the base board 11. In addition, in a specific application, the slit 131 may be in a projection range of a second cavity 1212, or may be in a projection range of a dorsal cavity 122. A relative position relationship between the slit 131 of the resonant cavity 13 and the coupling cavity 12 is not limited in this application.
In addition, during specific disposition, in addition to using a substrate integrated waveguide, the resonant cavity 13 may alternatively use a rectangular resonant cavity shown in FIG. 8. Alternatively, it may be understood that two rows of metal through holes 135 and the electric wall 136 in the substrate integrated waveguide are replaced with metal layers, to form a structure similar to the rectangular resonant cavity.
It may be understood that, in another implementation, the resonant cavity 13 may alternatively be of a type like a cylindrical resonant cavity. A specific type of the resonant cavity 13 is not limited in this application.
When the resonant cavity 13 is specifically disposed, the resonant cavity 13 may be directly formed on a first board surface of the base board 11, or a formed resonant cavity 13 may be fastened on a first board surface of the base board 11. A specific molding manner of the resonant cavity 11 is not limited in this application.
In addition, in a specific application, a length of the slit 131 may be controlled at about 0.5 λg, so that a transition apparatus can implement a broadband feature. λg is a wavelength of an electromagnetic wave propagating in a medium. The medium refers to the base board 11, the resonant cavity 13, or air. It should be noted that a wavelength of the electromagnetic wave propagated in the resonant cavity 13 may be understood as a wavelength of the electromagnetic wave propagated in a material medium of the resonant cavity 13, or a wavelength of the electromagnetic wave propagated in a cavity of the resonant cavity 13. It may be understood that, in another implementation, the length and a width of the slit 131 may alternatively be correspondingly set based on different requirements. A size of the slit 131 is not limited in this application. In addition, in an actual application, two, three, or more slits 131 may be provided. A plurality of slits may be disposed parallel to each other, or may be disposed intersecting each other. A quantity of disposed slits 131 and a position arrangement are not limited in this application.
For a gradient transition structure 021, as shown in FIG. 6, its main function is to implement impedance conversion between the resonant cavity 13 and the microstrip line 02, and implement conversion between a TE wave and a TEM wave.
A main body of the gradient transition structure 021 is a segment of microstrip gradient line. There are many forms of microstrip gradient lines. For example, the microstrip gradient line may be an arc gradient line, a linear gradient line, a polyline gradient line, or the like.
For example, as shown in FIG. 6, in the embodiment provided in this application, the microstrip gradient line (namely, an outline of an edge of the gradient transition structure) of the gradient transition structure 021 is an arc gradient line. It may be understood that, in a specific application, a form of the microstrip gradient line may be properly selected based on an actual situation. This is not limited in this application.
In addition, during specific disposition, to improve a connection effect between the waveguide 01 and the base board 11, a structure of the waveguide 01 may alternatively be adaptively designed.
For example, as shown in FIG. 9 and FIG. 10, in an embodiment provided in this application, a flange 011 is disposed on an end surface of one end (an upper end in the figure) of the waveguide 01, and a top surface of the flange 011 is configured to attach to a lower board surface of the base board 11. Specifically, a structural design of the flange 011 facilitates making the top surface of the flange 011 into a plane with high flatness. Therefore, adhesion between the waveguide 01 and the lower board surface of the base board 11 is improved, and an adverse situation like signal leakage is prevented.
In a specific implementation, a shape profile of the flange 011 may be adaptively set based on a cross-sectional shape of a cavity 010 in the waveguide 01. For example, when the cross-sectional shape of the cavity 010 in the waveguide 01 is rectangular, the flange 011 may alternatively be set to a rectangular. When the cross-sectional shape of the cavity 010 in the waveguide 01 is an ellipse, the flange 011 may alternatively be set to an ellipse.
Generally speaking, the flange 011 may be located at an edge of an opening of the cavity 010 in the waveguide 01, so that a signal can be effectively prevented from leaking from the opening of the cavity 010.
In addition, to improve signal transmission efficiency between the base board 11 and the waveguide 01, a cross-sectional shape of a through slot 111 may be the same as the cross-sectional shape of the cavity 010, to prevent adverse effects such as insertion loss and impedance mismatch when a signal is propagated between the waveguide 01 and the through slot 111 of the base board 11.
In addition, when the waveguide 01 is mounted to a lower side of the base board 11, to improve relative position precision between the waveguide 01 and the base board 11, a matching positioning structure may be disposed between the waveguide 01 and the base board 11, to ensure a relative position between the waveguide 01 and the base board 11.
Specifically, as shown in FIG. 11 and FIG. 12, in an embodiment provided in this application, a second positioning structure 012 is disposed on an upper side of the waveguide 01, and a third positioning structure 112 is disposed on a lower side of the base board 11. The second positioning structure 012 includes a positioning post. The third positioning structure 112 includes a positioning hole.
First, it should be noted that in FIG. 11, the base board 11 includes a plurality of through slots 111 disposed in an array (24 are shown in the figure, and are merely used as an example, and a specific quantity is not limited). In FIG. 12, the waveguide 01 includes a plurality of cavities 010 disposed in an array. After assembly between the base board 11 and the waveguide 01 is completed, the through slot 111 and the cavity 010 are coupled in a one-to-one correspondence. In this manner, coupling between a plurality of through slots 111 and cavities 010 can be implemented at the same time, to effectively increase a capacity of a transition apparatus 10, and facilitate manufacturing, and simplifying an assembly process.
It may be understood that, in an actual application, related structures such as a plurality of (for example, 24) coupling cavities 12 and resonant cavities 13 still need to be disposed on an upper board surface of the base board 11, to implement bridging between a plurality of microstrip lines 02 and a plurality of cavities 010.
In another implementation, a quantity of through slots 111 and a disposing position disposed in a single base board 11 may be properly adjusted based on different requirements. Correspondingly, a quantity of cavities 010 and a disposing position disposed in a single waveguide 01 may alternatively be properly adjusted based on different requirements. This is not specifically limited in this application.
In addition, in the embodiment provided in this application, to improve a connection effect between the base board 11 and the waveguide 01, the second positioning structure 012 includes two cap-shaped positioning posts, and the two cap-shaped positioning posts are respectively disposed at two diagonals of the waveguide 01. The third positioning structure 112 includes two positioning holes, and the two positioning holes are respectively disposed at two diagonals of the base board 11.
When the base board 11 and the waveguide 01 are assembled, a stable connection effect between the base board 11 and the waveguide 01 can be implemented by using the second positioning structure 012 and the third positioning structure 112.
It may be understood that, in a specific implementation, a cross section of the positioning hole may be a circular, ellipse, rectangular, or another polygon structure. Correspondingly, a cross section of the positioning post may be a circular, ellipse, rectangular, or another polygon structure. A quantity and positions of disposed positioning holes and disposed positioning posts may be properly adjusted based on an actual requirement. This is not limited in this application.
In addition, during assembly, to improve connection strength between the waveguide 01 and the base board 11, the waveguide 01 and the base board 11 may be fixedly connected by using a fastener.
For example, as shown in FIG. 11 and FIG. 12, in an embodiment provided in this application, the waveguide 01 has a plurality of through holes 013 (24 through holes are shown in the figure), and a lower board surface of the base board 11 has a plurality of threaded holes 113 (24 threaded holes are shown in the figure). In addition, the plurality of through holes 013 and the plurality of threaded holes 113 are disposed in a one-to-one correspondence. After a screw passes through the through hole 013 of the waveguide 01, the screw is screwed to the threaded hole 113 in the base board 11, so that the waveguide 01 and the base board 11 can be fixedly connected. Connection strength between the waveguide 01 and the base board 11 can be ensured by using the screw. In addition, a detachable connection is also convenient to be implemented, thereby having high flexibility.
It may be understood that, in another implementation, a fixed connection between the base board 11 and the waveguide 01 may alternatively be implemented in another manner. This is not specifically limited in this application.
The following methods can be used to manufacture a transition apparatus.
Specifically, with reference to FIG. 9 and FIG. 15, the method may include the following steps.

S1: Dispose a through slot 111 in a base board 11, and dispose a conducting layer on an inner wall of the through slot 111. A first end (an upper end) of the through slot 111 penetrates through a first board surface (an upper board surface), and a second end (a lower end) of the through slot 111 penetrates through a second board surface (a lower board surface).
S2: Dispose a coupling cavity 12 on the first board surface, to enable the coupling cavity 12 to be coupled to the first end of the through slot 111.
S3: Dispose a resonant cavity 13 on the first board surface. The resonant cavity 13 has at least one slit 131 and a connecting end (which is not shown in the figure). The slit 131 is coupled to the coupling cavity 12, and the connecting end is connected to a microstrip line 02.

During specific manufacturing, a process like cutting or numerical control machine tool processing may be used to dispose the through slot 111 in the base board 11. A disposing manner of the through slot 111 is not specifically limited in this application. When the conducting layer is disposed on the inner wall of the through slot 111, a conductive material (like copper, silver, or an alloy) may be directly formed on the inner wall of the through slot 111 by using a process like electroplating and meteorological sedimentation. A material and a preparation process of the conducting layer are not specifically limited in this application.
The resonant cavity 13 may be directly formed on the first board surface of the base board 111. Alternatively, the resonant cavity 13 may be manufactured first, and then a formed resonant cavity 13 is fastened on the first board surface by using a process like surface mounting. A molding manner of the resonant cavity 13 and an assembly process of the resonant cavity 13 and the base board 11 are not limited in this application.
In some preparation methods, the microstrip line 02 may alternatively be disposed on the first board surface of the base board 11.
For example, as shown in FIG. 16, the preparation method provided in this embodiment of this application further includes the following step.
S4: Dispose the microstrip line 02 on the first board surface. The microstrip line 02 includes a gradient transition structure 021, and a connecting end of the resonant cavity 13 is connected to the microstrip line 02 by using the gradient transition structure 021. In addition, during specific manufacturing, the microstrip line 02 may be directly formed on the first board surface of the base board 11 by using a process like coating or etching.
When the coupling cavity 12 is disposed on the first board surface, a fixed connection between the coupling cavity 12 and the base board 11 may be implemented in a welding manner. Alternatively, the coupling cavity 12 may be fixedly connected to the base board 11 by using a connecting piece like a screw or a buckle.
In addition, to improve relative position precision between the coupling cavity 12 and the base board 11, during assembly, the coupling cavity may be disposed at a target position of the first board surface by using an auxiliary tooling.
Specifically, the method may further include the following step.
S5: Position the coupling cavity at the target position of the base board by using the auxiliary tooling. The coupling cavity 12 has a first positioning structure 123, and the auxiliary tooling has a fastening structure configured to cooperate with the first positioning structure 123.
During assembly, the first positioning structure 123 may cooperate with the fastening structure, to implement relative fastening between the coupling cavity 12 and the auxiliary tooling, and then the coupling cavity 12 is transferred to the first board surface of the base board 11 by using the auxiliary tooling, to accurately mount the coupling cavity 12 at the target position of the base board 11. Subsequently, the coupling cavity 12 may be fastened on the upper board surface of the base board 11 by using a welding (for example, surface mounting or laser beam welding) process, to implement a fixed connection between the coupling cavity 12 and the base board 11.
For a waveguide 01, the waveguide 01 may be disposed on the second board surface of the base board 11, and a fixed connection between the waveguide 01 and the base board 11 is implemented.
During manufacturing, the method may include the following step.
S6: Attach a top surface of a flange 011 that is of an end face of a first end of a waveguide to the second board surface.
A structural design of the flange 011 facilitates making the top surface of the flange 011 into a plane with high flatness. Therefore, adhesion between the waveguide 01 and the lower board surface of the base board 11 is improved, and an adverse situation like signal leakage is prevented.
In addition, to improve relative position precision between the waveguide 01 and the base board 11, during manufacturing, the method may further include the following step.
S7: Dispose a second positioning structure (which is not shown in FIG. 9) in the waveguide 01, and dispose a third positioning structure (which is not shown in FIG. 9) on the second board surface of the base board 11.
During assembly, the second positioning structure and the third positioning structure may cooperate with each other, to ensure a relative position between the waveguide 01 and the base board 11. Finally, a fixed connection between the waveguide 01 and the base board 11 may be implemented by using a connecting piece like a screw or a buckle.
It may be understood that another method or process may alternatively be used when a transition apparatus 10 is manufactured. A method for preparing the transition apparatus 10 is not specifically limited in this application.
The following specifically describes beneficial effects of the transition apparatus provided in embodiments of this application with reference to experimental data.
FIG. 13 is a signal data simulation diagram of a transition apparatus 10.
In the figure, a horizontal coordinate represents a frequency, and a vertical coordinate represents reflected/transmission power. A solid line L1 represents an insertion loss. A dashed line M1 represents an echo of a port in the transition apparatus 10 and a dashed line M2 represents an echo of the other port in the transition apparatus 10.
It can be seen from FIG. 13 that the transition apparatus 10 can achieve a bandwidth range of -20 dB of about 71.7 GHz to 81.41 GHz. The insertion loss is about -2.36 dB. That is, the transition apparatus 10 provided in this embodiment of this application can achieve effect of a wide bandwidth range and a low insertion loss.
FIG. 14 is an electric field strength distribution diagram of a transition apparatus 10.
As can be seen from FIG. 14, a strong electric field is mainly distributed in an area A (that is, a corner of a coupling cavity) and an area B (that is, a corner of a through slot). A stable electric field is formed at a position where the bottom of a base board is in contact with a waveguide, and there is no strong electric field distribution. Therefore, the entire transition apparatus is insensitive to a bottom waveguide tolerance. Moreover, even if a mounted error is introduced, a low insertion loss can be achieved.
In an actual application, the transition apparatus may be applied to a plurality of different types of electronic devices, to implement coupling between a microstrip line and a waveguide.
For example, as shown in FIG. 17, the electronic device is a vehicle-mounted radar. The vehicle-mounted radar may include a chip 03 and a waveguide antenna 04. The chip may be disposed on an upper board surface of a base board 11, and is connected to a transition apparatus 10 by using a gradient transition structure 021 of a microstrip line 02. The waveguide antenna may be disposed at a lower side of the base board 11, and is coupled to a lower end of a waveguide 01. That is, bridging between the chip and the waveguide antenna may be implemented by using the transition apparatus 10.
In the foregoing embodiment, only the vehicle-mounted radar is used as an example for specific description. In a specific application, the electronic device may alternatively be a base station, a detector, or the like. A specific type of the electronic device is not limited in this application.
In a specific implementation, the electronic device provided with the transition apparatus may be further applied to various types of terminals such as an uncrewed aerial vehicle, a smart home, an intelligent manufacturing device, and a surveying and mapping device. Application scopes of the transition apparatus and the electronic device provided with the transition apparatus are not limited in this application.
The foregoing descriptions are merely specific implementations of this application, but are not intended to limit the protection scope of this application. Any variation or replacement readily figured out by a person skilled in the art in the technical scope disclosed in this application shall fall within the protection scope of this application. Therefore, the protection scope of this application shall be subject to the protection scope of the claims.

Claims

A transition apparatus, wherein the transition apparatus comprises:
a base board, having a first board surface and a second board surface, wherein the base board has a through slot, a first end of the through slot penetrates through the first board surface, a second end of the through slot penetrates through the second board surface, and an inner wall of the through slot has a conducting layer;

a coupling cavity, disposed on the first board surface, wherein the coupling cavity is coupled to the first end of the through slot; and

a resonant cavity, disposed on the first board surface, wherein the resonant cavity has at least one slit and a connecting end, the slit is coupled to the coupling cavity, and the connecting end is connected to a microstrip line.
The transition apparatus according to claim 1, wherein the transition apparatus further comprises the microstrip line disposed on the first board surface, and the microstrip line comprises a gradient transition structure; and
the connecting end is connected to the microstrip line by using the gradient transition structure.
The transition apparatus according to claim 1 or 2, wherein the second end of the through slot is connected to a waveguide.
The transition apparatus according to any one of claims 1 to 3, wherein a structure of the coupling cavity is a stepped structure with an opening toward the first board surface of the base board.
The transition apparatus according to claim 4, wherein an edge of the opening is welded to the first board surface of the base board.
The transition apparatus according to any one of claims 1 to 5, wherein the coupling cavity has a first positioning structure; and
the first positioning structure is configured to position the coupling cavity at a target position of the base board.
The transition apparatus according to any one of claims 1 to 6, wherein a cross-sectional shape of the through slot is the same as or similar to a cross-sectional shape of the waveguide.
The transition apparatus according to any one of claims 1 to 7, wherein the resonant cavity comprises a substrate integrated waveguide;
a first end of the substrate integrated waveguide comprises the connecting end, and a second end of the substrate integrated waveguide is provided with an electric wall; and

the slit is provided on a surface that is of the substrate integrated waveguide and that is away from the base board.
The transition apparatus according to any one of claims 1 to 8, wherein the second board surface of the base board is connected to a first end of the waveguide.
The transition apparatus according to any one of claims 1 to 9, wherein a length of the slit is 0.5 λg; and
λg is a wavelength of an electromagnetic wave propagated in a first medium, and the first medium is the base board, the resonant cavity, or air.
The transition apparatus according to any one of claims 1 to 10, wherein the transition apparatus further comprises the waveguide, an end face of the first end of the waveguide has a flange, and a top surface of the flange is attached to the second board surface.
The transition apparatus according to claim 11, wherein the waveguide has a second positioning structure, and the second board surface of the base board has a third positioning structure adapted to the second positioning structure.
An electronic device, comprising a chip and a waveguide antenna, and further comprising the transition apparatus according to any one of claims 1 to 12, wherein
the chip is connected to a connecting end of a resonant cavity by using a microstrip line, and the waveguide antenna is connected to a second end of a through slot by using a waveguide.
The electronic device according to claim 13, wherein the electronic device is a radar.
A terminal, comprising the electronic device according to claim 13 or 14.
A preparation method, comprising:
disposing a through slot in a base board having a first board surface and a second board surface, and disposing a conducting layer on an inner wall of the through slot, wherein a first end of the through slot penetrates through the first board surface, and a second end of the through slot penetrates through the second board surface;

disposing a coupling cavity on the first board surface, wherein the coupling cavity is coupled to the first end of the through slot; and

disposing a resonant cavity on the first board surface, wherein

the resonant cavity has at least one slit and a connecting end, the slit is coupled to the coupling cavity, and the connecting end is connected to a microstrip line.
The preparation method according to claim 16, wherein the method further comprises:
disposing the microstrip line on the first board surface, wherein

the microstrip line comprises a gradient transition structure, and the connecting end is connected to the microstrip line by using the gradient transition structure.
The preparation method according to claim 16 or 17, wherein the method further comprises: connecting the second end of the through slot to a waveguide.
The preparation method according to any one of claims 16 to 18, wherein a structure of the coupling cavity is a stepped structure with an opening toward the first board surface of the base board.
The preparation method according to claim 19, wherein the method further comprises: welding an edge of the opening to the first board surface of the base board.
The preparation method according to any one of claims 16 to 20, wherein the coupling cavity has a first positioning structure; and
the method further comprises:
positioning the coupling cavity at a target position of the base board by using an auxiliary tooling, wherein the auxiliary tooling has a fastening structure configured to cooperate with the first positioning structure.
The preparation method according to any one of claims 16 to 21, wherein the method further comprises:
attaching a top surface of a flange on an end face of a first end of the waveguide to the second board surface.
The preparation method according to claim 22, wherein the method further comprises:
disposing a second positioning structure on the waveguide, and disposing a third positioning structure on the second board surface of the base board; and

making the second positioning structure cooperate with the third positioning structure, to position the waveguide on the second board surface.