CN218101697U - Electromagnetic shielding structure for radar sensor, radar sensor and electronic device - Google Patents

Abstract

The embodiment of the application relates to the technical field of radar antennas and discloses an electromagnetic shielding structure for a radar sensor, the radar sensor and electronic equipment. The radar sensor comprises a first medium substrate, wherein a chip and a radiation part connected with the chip through a microstrip line are arranged on the first medium substrate. The electromagnetic shielding structure comprises a shielding cover with an electromagnetic band gap structure, the shielding cover is covered on the microstrip line, and the electromagnetic band gap structure faces one side of the microstrip line. The electromagnetic shielding structure for the radar sensor, the radar sensor and the electronic device provided by the embodiment of the application can effectively reduce electromagnetic radiation interference formed by microstrip lines in the radar antenna.

Description

Electromagnetic shielding structure for radar sensor, radar sensor and electronic device

Technical Field

The embodiment of the application relates to the technical field of radar antennas, in particular to an electromagnetic shielding structure for a radar sensor, the radar sensor and electronic equipment.

Background

With the increasing development of scientific technology, intelligent driving technology is beginning to be popularized in daily life. The intelligent driving is an important gripper combining industrial revolution and informatization, the rapid development can change the flowing modes of people, resource elements and products, and the human life is changed subversively. The sensor plays a key role in intelligent driving, and is a channel for an intelligent system of an automobile to acquire external information. In order to obtain range, speed and angle information of a target, a vision system of an automobile is generally configured with a radar sensor.

However, when the radar antenna of the radar sensor operates, the winding of the microstrip line generates harmonic waves, thereby causing electromagnetic radiation interference to the outside. Therefore, how to effectively reduce the electromagnetic radiation interference formed by the microstrip line in the radar antenna is an important problem.

SUMMERY OF THE UTILITY MODEL

An object of the present invention is to provide an electromagnetic shielding structure for a radar sensor, and an electronic device, which can effectively reduce electromagnetic radiation interference formed by a microstrip line in a radar antenna.

In order to solve the above technical problem, an embodiment of the present application provides an electromagnetic shielding structure for a radar sensor, where the radar sensor includes a first dielectric substrate, and the first dielectric substrate is provided with a chip and a radiation portion connected to the chip through a microstrip line. The battery shielding structure comprises a shielding cover with an electromagnetic band gap structure, the shielding cover is covered on the microstrip line, and the electromagnetic band gap structure faces one side of the microstrip line.

Embodiments of the present application also provide a radar sensor including the above electromagnetic shielding structure for a radar sensor.

Embodiments of the present application also provide an electronic device including the above radar sensor.

According to the electromagnetic shielding structure for the radar sensor, the radar sensor and the electronic device, the electromagnetic band gap structure is adopted on the shielding cover, and the electromagnetic wave radiated to the surrounding environment by the microstrip line is shielded through the band elimination characteristic of the electromagnetic band gap structure. That is, the propagation of the electromagnetic wave radiated from the microstrip line to the outside is suppressed by the characteristic that the electromagnetic band gap structure blocks the propagation of the electromagnetic wave within a certain band gap. Therefore, mutual coupling among the microstrip lines is inhibited, the influence of radiation of the microstrip lines on an antenna directional diagram is inhibited, and the purpose of reducing electromagnetic radiation interference formed by the microstrip lines is achieved.

In some embodiments, the shielding case includes a second dielectric substrate, a plurality of metal patches are disposed on a surface of the second dielectric substrate facing the microstrip line, a grounded metal layer is disposed on a surface of the second dielectric substrate facing away from the microstrip line, and each metal patch is electrically connected to the metal layer through a metal via hole on the second dielectric substrate to form an electromagnetic bandgap structure. Therefore, when the shielding cover is influenced by electromagnetic waves, current is generated on the metal patches, inductance is formed when the current flows through the metal through holes and the metal layers, and capacitance is formed between the metal patches and the ground. Thus, a resonant circuit including capacitance and inductance is formed, and the resonant circuit has a characteristic of preventing electromagnetic wave propagation within a certain band gap.

In some embodiments, a distance between two adjacent metal patches is less than a side length of the metal patches.

In some embodiments, each metal patch is square in shape, and the sum of the side length of each metal patch and the distance between two adjacent metal patches is less than half of the operating wavelength.

In some embodiments, the distance between the shield and the first dielectric substrate is half the operating wavelength.

In some embodiments, the shielding can includes a third dielectric substrate, the electromagnetic bandgap structure includes a first conductive unit disposed on the third dielectric substrate, a second conductive unit, and a metal sheet surrounding the first conductive unit and the second conductive unit, a portion of the first conductive unit and the second conductive unit are disposed in parallel and spaced apart to form a capacitor structure, and the second conductive unit is electrically connected to the metal sheet. Thus, when the electromagnetic band gap structure is influenced by electromagnetic waves, current is generated on the conductive unit, and when the current flows through the conductive unit, inductance is formed, so that a resonance circuit is formed with capacitance between the conductive unit and the electromagnetic band gap structure, and band resistance characteristics are provided in a certain frequency. Meanwhile, the electromagnetic band gap structure is formed by the arrangement of the conductive units, so that the shielding case structure is more compact.

In some embodiments, there are two first conductive units, two first conductive units are disposed opposite to each other, and there are four second conductive units, wherein two second conductive units are disposed between the two first conductive units and simultaneously form a capacitor structure with portions of the two first conductive units, and the other two second conductive units are disposed corresponding to the two first conductive units and form a capacitor structure with portions of the corresponding first conductive units. In this way, more resonance points can be introduced in the electromagnetic bandgap structure.

In some embodiments, the first conductive unit, the second conductive unit and the metal sheet are metal films or metal stickers. Thus, the electromagnetic band gap structure can be conveniently formed on the dielectric substrate through the stickability of the metal film or the metal sticker.

In some embodiments, the shielding case includes a fourth dielectric substrate, the electromagnetic bandgap structure includes two metal strips oppositely and separately disposed on the fourth dielectric substrate, and a metal outer frame disposed on the fourth dielectric substrate and surrounding the two metal strips, and each metal strip is electrically connected to the metal outer frame through a connecting piece. Thus, a capacitor is formed between the two metal strips, and an inductor is formed when current flows through the metal frame, so that a resonance circuit containing the capacitor and the inductor is formed to prevent electromagnetic wave propagation in a certain band gap.

In some embodiments, the metal strip, the metal bezel, and the connecting tab are metal films or metal decals. Thus, the electromagnetic band gap structure can be conveniently formed on the dielectric substrate through the adhesiveness of the metal film or the metal sticker.

Drawings

One or more embodiments are illustrated by way of example in the accompanying drawings, which correspond to the figures in which like reference numerals refer to similar elements and which are not to scale unless otherwise specified.

Fig. 1 is a schematic diagram of an arrangement structure of microstrip lines in a radar sensor according to some embodiments of the present application;

FIG. 2 is a schematic illustration of an electromagnetic shielding structure of a radar sensor provided by some embodiments of the present application;

FIG. 3 is a cross-sectional schematic view of an electromagnetic shielding structure of a radar sensor provided by some embodiments of the present application;

FIG. 4 is a schematic bottom view of a shield can of an electromagnetic shielding structure of a radar sensor provided in some embodiments of the present application;

FIG. 5 is a schematic view of a radar sensor employing a metal shield in some cases;

fig. 6 is a comparison diagram of isolation of microstrip lines in different situations where a microstrip line covered metamaterial shield and a microstrip line covered metal shield and a microstrip line uncovered shield are provided in some embodiments of the present application;

fig. 7 is a microstrip line insertion loss comparison graph for different situations where a microstrip line covered metamaterial shield and a microstrip line covered metal shield and a microstrip line uncovered shield are provided according to some embodiments of the present application;

fig. 8 is a graph comparing the electric field strength of cross sections of microstrip line covered metamaterial shield and microstrip line covered metal shield, microstrip line uncovered shield according to some embodiments of the present application;

FIG. 9 is a dispersion plot of a shield provided by some embodiments of the present application;

fig. 10 is a schematic diagram of a planar electromagnetic bandgap structure provided by some embodiments of the present application;

fig. 11 is a schematic diagram of yet another planar electromagnetic bandgap structure provided by some embodiments of the present application;

FIG. 12 is a schematic view of an arrangement of a radar sensor provided by some embodiments of the present application when a metamaterial shield is used;

fig. 13 is a schematic top view of a radar sensor provided in some embodiments of the present application when a metamaterial shielding cover is used.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the following describes each embodiment of the present application in detail with reference to the accompanying drawings. However, it will be appreciated by those of ordinary skill in the art that numerous technical details are set forth in various embodiments of the present application in order to provide a better understanding of the present application. However, the technical solution claimed in the present application can be implemented without these technical details and various changes and modifications based on the following embodiments. The following embodiments are divided for convenience of description, and should not constitute any limitation to the specific implementation manner of the present application, and the embodiments may be mutually incorporated and referred to without contradiction.

The radar technology adopts electromagnetic waves to realize effective detection of targets, and is not only widely applied to the aerospace field, but also increasingly applied to daily life. For example, with the development of smart driving technology and unmanned driving technology, radar sensors are widely used in automobile vision systems to detect target objects in the surrounding environment of a driving area. In order to obtain distance, speed and angle information of a target, frequency modulated continuous wave radar (FMCW radar) often adopts a multi-input multi-output (MIMO) operation mode with a plurality of transmitting and receiving antennas. Because the millimeter wave transceiver of the radar sensor is usually small, the output and input port of the millimeter wave transceiver needs to be connected to an external transceiving antenna through a section of microstrip line of tens of microns to hundreds of microns.

In practical applications, the windings of the microstrip lines radiate, and therefore need to be shielded by means of a shield or the like. In some cases, a metal sheet is generally used as the shield case. However, the parallel dual-plate formed by the shielding case of the metal thin plate and the floor of the microstrip line can cause a new guided wave mode, thereby affecting or even deteriorating the original radio frequency performance. Moreover, once the metal shielding cover is set too high, the directional diagram of the antenna is also affected, the metal shielding cover with lower height is difficult to process, and the difference between different sample pieces is large.

Some embodiments of the present application use an EBG (electromagnetic band gap) structure to make the shield, also referred to as a metamaterial shield. Through the band-stop characteristic of the electromagnetic band-gap structure, the coupling between the feeder lines of the antenna can be effectively reduced, and the isolation is improved. Therefore, radiation leakage of the microstrip line is effectively prevented, and meanwhile, the original radio frequency performance is not affected. Fig. 1 is a schematic structural diagram of an arrangement of microstrip lines in a radar sensor according to some embodiments of the present disclosure, and fig. 2 is a schematic structural diagram of a radar sensor loaded with a metamaterial shield according to some embodiments of the present disclosure.

As shown in fig. 2, some embodiments of the present application provide an electromagnetic shielding structure for a radar sensor. The radar sensor comprises a first dielectric substrate 10, wherein a chip 14 and a radiation part 15 connected with the chip 14 through a microstrip line 16 are arranged on the first dielectric substrate 10. The electromagnetic shielding structure includes a shielding case 20 having an electromagnetic band gap structure, and the shielding case 20 is covered on the microstrip line 16, and the electromagnetic band gap structure faces the microstrip line 16 side.

The first dielectric substrate 10 is a carrier plate of a radiation structure of a radar sensor. The first dielectric substrate 10 has a first surface 11 and a second surface 12 (shown in fig. 8) which are oppositely disposed, where the first surface 11 and the second surface 12 are one of a front surface and a back surface of the first dielectric substrate 10, and the first dielectric substrate 10 may be a plate material with a high dielectric constant, or may be a common circuit board. A grounding plate 13 is arranged on the first surface 11 of the first dielectric substrate 10, and the grounding plate 13 forms a ground plane of the radar sensor radiation structure and can reflect electromagnetic wave signals, so that the radar sensor radiation structure can radiate signals directionally. The chip 14 is a control unit of the radiating structure of the radar sensor, which controls the signal radiation and signal reception of the radiating structure. The chip 14 feeds electricity to the radiation section 15 through the microstrip line 16, so that the radiation section 15 can radiate an electromagnetic wave signal outward. The radiating portion 15 may be a microstrip patch antenna arranged in an array, and patch units arranged on the same straight line may be connected in series. The radiating portion 15 may also be a comb-shaped microstrip array antenna.

The shield case 20 is a shielding portion of the radar sensor for shielding electromagnetic radiation of the microstrip line 16. The shielding case 20 is disposed on the first dielectric substrate 10 and spaced apart from the first dielectric substrate 10, and is used for shielding the microstrip line 16 from electromagnetic radiation in the surrounding space. Unlike the sheet metal shield 20 used in some cases, some embodiments of the present application use a shield 20 provided with an electromagnetic bandgap structure. The electromagnetic bandgap structure is a resonant structure capable of blocking the propagation of electromagnetic waves within a certain bandgap. Through the band-stop characteristic of the electromagnetic band-gap structure, not only can a shielding effect be achieved, but also in the band-stop frequency band of the electromagnetic band-gap structure, a high-impedance state is formed on the surface of the shielding cover 20, and except a quasi-TEM mode transmitted by the microstrip line 16, electromagnetic waves in other modes cannot be transmitted, so that the shielding cover 20 can be ensured not to introduce an extra coupling field to a channel where other antennas are located.

In designing the radiation structure of the radar sensor, in order to match the input impedance of the power feed to each radiation section 15, the microstrip lines 16 for feeding power to each radiation section 15 are usually bent and provided on the dielectric substrate, and the lengths of the microstrip lines 16 are made uniform. When the radar sensor actually operates, electromagnetic radiation exists on each microstrip line 16. Since the chip 14 and the microstrip line 16 are located on the same side of the first dielectric substrate 10 as the array antenna, electromagnetic waves radiated by the microstrip line 16 not only affect each other, but also participate in forming a radiation pattern of the radiation structure, so that the radiation pattern formed by radiation of the radiation structure is distorted, and the detection field angle of the radar sensor is affected.

In the electromagnetic shielding structure of the radar antenna according to some embodiments of the present application, the shielding cover 20 is of an electromagnetic band gap structure, and the electromagnetic wave radiated from the microstrip line 16 to the surrounding environment is shielded by the band stop characteristic of the electromagnetic band gap structure. That is, the propagation of the electromagnetic wave radiated to the outside from the microstrip line 16 is suppressed by the characteristic that the electromagnetic band gap structure blocks the propagation of the electromagnetic wave within a certain band gap. Thereby suppressing mutual coupling between the microstrip lines 16 and suppressing the influence of radiation of the microstrip lines 16 on the antenna pattern, and achieving the purpose of reducing electromagnetic radiation interference formed by the microstrip lines 16.

As shown in fig. 2 to 4, in some embodiments of the present application, the shielding case 20 may include a second dielectric substrate 21, a plurality of metal patches 22 are disposed on a surface of the second dielectric substrate 21 facing the microstrip line 16, a grounded metal layer 23 is disposed on a surface of the second dielectric substrate 21 facing away from the microstrip line 16, and each metal patch 22 is electrically connected to the metal layer 23 through a metal via 24 on the second dielectric substrate 21 to form an electromagnetic bandgap structure.

When the shield 20 is affected by electromagnetic waves, a current is induced in the metal patch 22. The current flowing through the metal via 24 of the second dielectric substrate 21 and the metal layer 23 connected to ground will form an inductance. The charge accumulated on the metal patches 22 causes a capacitance to form between the metal patches 22. Thus, the electromagnetic bandgap structure on the shielding can 20 can be equivalent to a resonant circuit including an inductor and a capacitor. At the resonance frequency, the surface of the shield case 20 assumes a high impedance state, and propagation of electromagnetic waves is suppressed.

It should be noted that the resonant frequency of the electromagnetic bandgap structure can be adjusted by changing the size parameters. For example, in order to obtain a desired resonant frequency in shielding, the size of the metal patch 22, the arrangement distance of the metal patches 22, or the size of the second dielectric substrate 21 may be changed. In addition, a plurality of metal patches 22 may be periodically arranged on the second dielectric substrate 21, so that the degree of correlation between the size parameter variation of the metal patches 22 and the variation of the resonant frequency is high.

In some embodiments of the present application, the distance between two adjacent metal patches 22 is less than the side length of the metal patches 22.

For example, in practical cases, the side length of each metal patch 22 may be 0.7mm (millimeter), and the distance between two adjacent metal patches 22 may be 0.3mm.

In some embodiments of the present application, each metal patch 22 is square in shape, and the sum of the side length of each metal patch 22 and the distance between two adjacent metal patches is less than half of the operating wavelength.

In addition, the shielding performance of the shield 20 in an actual situation can also be adjusted by controlling the distance between the shield 20 and the microstrip line 16.

In some embodiments of the present application, the distance (indicated by X in fig. 2) between the shield 20 and the first dielectric substrate 10 is half the operating wavelength.

In fig. 1, microstrip lines 16 designed in the vehicle millimeter wave band 76 to 79GHz (gigahertz) in practical cases are shown, the thickness of the first dielectric substrate 10 is 5mil, and the pitch of the microstrip lines 16 is 2mm. Fig. 5 is a diagram obtained by adding a shielding case (i.e., a metal shielding case 101) formed by a metal thin plate with an open periphery to the diagram of fig. 1, wherein the height (indicated by Y in fig. 5) of the metal shielding case 101 from the plane where the microstrip line 16 is located is set to be 0.5mm. Fig. 6 and 7 compare the isolation of the microstrip line and the insertion loss of the microstrip line in different situations where the microstrip line covers the metal shield, the microstrip line does not cover the shield, and the microstrip line covers the metamaterial shield, respectively. It can be seen that the isolation and insertion loss of the microstrip lines are relatively consistent in the case of loading the metamaterial shield and the case of not loading the metamaterial shield provided by some embodiments of the present application, and the shield formed by loading the metal sheet deteriorates the isolation and insertion loss of the microstrip lines. The reason is that the metal shield couples with the microstrip line, causing surface electromagnetic waves and some guided wave modes existing between the parallel metal plates.

Fig. 8 compares the electric field distribution of the cross section of the microstrip line covered metal shield, the microstrip line uncovered shield and the microstrip line covered metamaterial shield in different situations, where the selected reference line is the position of the dotted line a in fig. 1. As can be seen from fig. 8, after the metal shield is loaded, the electric field in the space has an increase of about 15dB (decibel) in strength compared to the case where the shield is not loaded. These electric fields cause the isolation between the microstrip lines to deteriorate. The distribution of the electric field intensity of the shielding case loaded and the distribution of the electric field intensity of the shielding case not loaded are relatively close. The maximum electric field intensity at the position of 4mm in fig. 8 is because only the microstrip line located at the left side of the drawing in fig. 1 is fed, and the peak value of the electric field intensity at the position of 6mm in the drawing is because a relatively strong electric field is induced between the microstrip line 16 located at the right side of the drawing in fig. 1 and the ground plate 13.

The dispersion curve of the shielding can provided by some embodiments of the present application is shown in fig. 9, and it can be seen from fig. 9 that the electromagnetic bandgap structure can form a good band-stop effect between 70 GHz and 77 GHz. Therefore, in the band-stop frequency band of the shielding cover, except for the quasi-TEM mode of microstrip line transmission, electromagnetic waves in other modes cannot be transmitted, and the shielding cover can be ensured not to introduce additional coupling fields to enter other antenna channels.

In addition, the electromagnetic band gap structure can also be used for eliminating a via hole structure besides the via hole structure. That is, in addition to the electromagnetic bandgap structure realized by loading the via hole, a planar electromagnetic bandgap structure may be formed on a dielectric substrate to shield electromagnetic radiation interference formed by the microstrip line. Two specific forms are given below to illustrate the manner in which the planar electromagnetic bandgap structure is formed.

As shown in fig. 10, in some embodiments of the present application, the shielding can 20 includes a third dielectric substrate 30, the electromagnetic bandgap structure includes a first conductive unit 31, a second conductive unit 32 and a metal sheet 33 disposed on the third dielectric substrate 30, the metal sheet 33 surrounds the first conductive unit 31 and the second conductive unit 32, a portion of the first conductive unit 31 is parallel to and spaced apart from the second conductive unit 32 to form a capacitor structure, and the second conductive unit 32 is electrically connected to the metal sheet 33.

As such, the portion of the first conductive element 31 and the second conductive element 32 form a capacitor, also referred to as an interdigital structure. The interdigital structure is formed by a plurality of micro-strip fingers which are interwoven and coupled by metal patterns on the front surface or the back surface of a dielectric substrate, and when the electromagnetic band gap structure is influenced by electromagnetic waves, current generated on the metal patterns provides capacitance characteristics through the coupling effect of the interdigital structure, so the interdigital structure is also called as interdigital capacitance. At the same time, the passage of current through the conductive element creates an inductance. The metal pattern can equally be equivalent to a resonant circuit comprising an inductor and a capacitor.

In practical cases, the first conductive element 31 and the second conductive element 32 may be in a strip structure, and surrounded by a hollow area formed by the metal sheet 33, and the hollow area of the metal sheet 33 may be in an oval shape. The number of the capacitor structures formed by the portion of the first conductive unit 31 and the second conductive unit 32 may be one, two, or more.

With continued reference to fig. 10, in some embodiments, there may be two first conductive elements 31, and the two first conductive elements 31 are disposed opposite to each other. There are four second conductive units 32, two second conductive units 32 are disposed between the two first conductive units 31 and simultaneously form a capacitor structure with portions of the two first conductive units 31, and the other two second conductive units 32 are disposed corresponding to the two first conductive units 31 and form a capacitor structure with portions of the corresponding first conductive units 31.

In addition, the first conductive unit 31, the second conductive unit 32 and the metal sheet 33 may be a metal film or a metal sticker.

The first conductive unit 31, the second conductive unit 32 and the metal sheet 33 which are made and molded by using a metal film or a metal sticker may be adhered to the front surface or the back surface of the third dielectric substrate 30 by a double-sided tape, or sprayed on the front surface or the back surface of the third dielectric substrate 30 by using a metal spray paint, so as to form the first conductive unit 31, the second conductive unit 32 and the metal sheet 33 in a specific shape.

In other embodiments, thicker metal patches may be used for the first conductive unit 31, the second conductive unit 32 and the metal sheet 33.

In some embodiments of the present application, a more compact electromagnetic bandgap structure is also provided. As shown in fig. 11, the shielding case 20 includes a fourth dielectric substrate 40, the electromagnetic bandgap structure includes two metal strips 41 disposed on the fourth dielectric substrate 40 in an opposing and spaced manner, and a metal frame 42 disposed on the fourth dielectric substrate 40 and surrounding the two metal strips 41, and each metal strip 41 is electrically connected to the metal frame 42 through a connecting piece 43.

Two metal strips 41 form a capacitive structure. When the electromagnetic bandgap structure is affected by electromagnetic waves, a current is generated on the metal structure, and the current forms an inductor when passing through the metal frame 42. By varying the capacitive impedance and the inductive impedance, the resonant frequency of the electromagnetic bandgap structure can be adjusted to suit the resonant frequency required by the shielding enclosure 20.

In practical cases, the metal outer frame 42 may be circular, elliptical, or a polygonal ring.

In addition, the metal strip 41, the metal outer frame 42, and the connecting sheet 43 may be metal films or metal stickers.

The metal strip 41, the metal outer frame 42 and the connecting piece 43, which are made of metal films or metal stickers, can be adhered to the front or back of the fourth dielectric substrate 40 by double-sided adhesive tape, or sprayed on the front or back of the fourth dielectric substrate 40 by metal paint, so as to form the metal strip 41, the metal outer frame 42 and the connecting piece 43 in specific shapes.

In other embodiments, a thicker metal patch can be used for the metal strip 41, the metal outer frame 42 and the connecting piece 43.

Some embodiments of the present application further provide a radar sensor, which includes a first dielectric substrate 10 and a shield can 20. The first dielectric substrate 10 is provided with a chip 14 and a radiation portion 15 connected to the chip 14 via a microstrip line 16. The shield 20 has an electromagnetic bandgap structure, and the shield 20 is disposed on the microstrip line 16.

In addition, as shown in fig. 12 and 13, there may be a plurality of radiation portions 15, each radiation portion 15 is electrically connected to the chip 14 through one microstrip line 16, and the shield 20 covers the plurality of microstrip lines 16. Each radiating portion 15 may be an antenna array formed by connecting a plurality of radiating patches.

Moreover, the chip 14 can be covered by the shielding cover 20, and the chip 14 and the microstrip line 16 can be covered by the shielding cover 20 at the same time, so that electromagnetic radiation on the chip 14 and electromagnetic radiation on the microstrip line 16 can be simultaneously shielded, and the radiation patch is prevented from being affected.

It should be noted that when the shield 20 is only covered on the microstrip line 16, the chip 14 can be directly covered with a metal thin plate to achieve a shielding effect.

Some embodiments of the present application also provide an electronic device including the radar sensor in the above embodiments.

The electronic device can be used in a vision system of an automobile, so that the vision system of the automobile can detect information of a target object and an obstacle in the surrounding environment of a driving area, and a control system of the automobile can send out warning information in time. For example, when the electronic device is used for collision avoidance and early warning of a vehicle, scene information acquired by the radar sensor in a driving area of the vehicle can be acquired, and obstacle information contained in a detection area of the radar sensor is acquired. And generating a target early warning signal under the condition of determining that the early warning triggering condition is met according to the obstacle information of the target obstacle.

It will be understood by those of ordinary skill in the art that the foregoing embodiments are specific examples of implementations of the present application, and that various changes in form and details may be made therein without departing from the spirit and scope of the present application.

Claims (14)

1. An electromagnetic shielding structure for a radar sensor, comprising:

the radar sensor comprises a first medium substrate, wherein a chip and a radiation part connected with the chip through a microstrip line are arranged on the first medium substrate; the electromagnetic shielding structure comprises a shielding case with an electromagnetic band gap structure, the shielding case is covered on the microstrip line, and the electromagnetic band gap structure faces one side of the microstrip line.

2. The electromagnetic shielding structure for a radar sensor according to claim 1, wherein:

the shielding case comprises a second dielectric substrate, a plurality of metal patches are arranged on one surface of the second dielectric substrate facing the microstrip line, a grounded metal layer is arranged on one surface of the second dielectric substrate facing away from the microstrip line, and each metal patch is electrically connected with the metal layer through a metal via hole in the second dielectric substrate to form the electromagnetic band gap structure.

3. The electromagnetic shielding structure for a radar sensor according to claim 2, wherein:

the distance between two adjacent metal patches is smaller than the side length of the metal patches.

4. The electromagnetic shielding structure for a radar sensor according to claim 2, wherein:

each metal patch is square, and the sum of the side length of each metal patch and the distance between two adjacent metal patches is less than half of the working wavelength.

5. The electromagnetic shielding structure for a radar sensor according to claim 2, wherein:

the distance between the shielding cover and the first dielectric substrate is half of the working wavelength.

6. The electromagnetic shielding structure for a radar sensor according to claim 1, wherein:

the shielding cover comprises a third dielectric substrate, the electromagnetic band gap structure comprises a first conductive unit, a second conductive unit and a metal sheet, the first conductive unit, the second conductive unit and the metal sheet are arranged on the third dielectric substrate, the metal sheet surrounds the first conductive unit and the second conductive unit, the first conductive unit and the second conductive unit are arranged in parallel at intervals to form a capacitor structure, and the second conductive unit is electrically connected with the metal sheet.

7. The electromagnetic shielding structure for a radar sensor according to claim 6, characterized in that:

the number of the first conductive units is two, the two first conductive units are oppositely arranged, the number of the second conductive units is four, the two second conductive units are arranged between the two first conductive units and form a capacitor structure with parts of the two first conductive units at the same time, and the other two second conductive units are arranged corresponding to the two first conductive units and form a capacitor structure with parts of the corresponding first conductive units.

8. The electromagnetic shielding structure for a radar sensor according to claim 6 or 7, characterized in that:

the first conductive unit, the second conductive unit and the metal sheet are metal films or metal stickers.

9. The electromagnetic shielding structure for a radar sensor according to claim 1, wherein:

the shielding case comprises a fourth dielectric substrate, the electromagnetic band gap structure comprises two metal strips which are oppositely arranged on the fourth dielectric substrate at intervals, and a metal outer frame which is arranged on the fourth dielectric substrate and surrounds the two metal strips, and each metal strip is electrically connected with the metal outer frame through a connecting sheet.

10. The electromagnetic shielding structure for a radar sensor according to claim 9, characterized in that:

the metal strip, the metal outer frame and the connecting sheet are metal films or metal stickers.

11. A radar sensor, comprising:

the electromagnetic shielding structure for a radar sensor of any one of claims 1 to 10.

12. The radar sensor of claim 11, wherein:

the antenna array that the radiation portion formed for a plurality of radiation paster connection, the radiation portion has a plurality ofly, every the radiation portion through one microstrip line with the chip is connected, the shield cover establishes many microstrip lines.

13. The radar sensor of claim 11 or 12, wherein:

the shielding cover also covers the chip.

14. An electronic device, comprising:

the radar sensor of any one of claims 11 to 13.

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