CN117791084A - Antenna device and vehicle - Google Patents

Abstract

An antenna device and a vehicle are provided. The antenna device includes: a substrate composed of a light-transmitting material; the radiator is positioned on one side of the substrate and is composed of microstrip lines, and the microstrip lines are formed based on a metal grid structure; the grounding plate is positioned on one side of the substrate opposite to the radiator, the grounding plate is of a metal grid structure, the grounding plate is provided with a first connecting end and a second connecting end, and the first connecting end and the second connecting end are used for being connected with a direct-current power supply to heat the grounding plate. In this application embodiment, DC power supply can be connected to the earth plate, has integrated the electrical heating function, helps solving the problem that glass freezes the fog in the wet weather of sleet, improves the security of traveling.

Description

Antenna device and vehicle

Technical Field

The embodiment of the application relates to the technical field of wireless communication, and more particularly relates to an antenna device and a vehicle.

Background

With the rapid development of intelligent driving assistance technology, the requirements on the environment sensing capability of vehicles are increasingly increased. The vehicle-mounted 77GHz millimeter wave radar is one of the core sensors of the unmanned vehicle due to the characteristics of high-precision detection, small volume, light weight, long-distance measurement, strong anti-interference capability and the like. In order to obtain a far radar detection distance and ensure communication quality, the antenna position is usually selected in a region through which visible light such as a front windshield, a vehicle window or a rearview mirror can penetrate. However, in wet weather, the glass of the automobile is easy to fog, which affects the vision of the driver and may cause traffic accidents.

Disclosure of Invention

The embodiment of the application provides an antenna device and a vehicle. Various aspects of embodiments of the present application are described below.

In a first aspect, there is provided an antenna device comprising: a substrate composed of a light-transmitting material; the radiator is positioned on one side of the substrate and is composed of microstrip lines, and the microstrip lines are formed based on a metal grid structure; the grounding plate is positioned on one side of the substrate opposite to the radiator, the grounding plate is of a metal grid structure, the grounding plate is provided with a first connecting end and a second connecting end, and the first connecting end and the second connecting end are used for being connected with a direct-current power supply to heat the grounding plate.

In some possible implementations, the first connection end is located at one end of the ground plate, and the second connection end is located at an opposite end of the end where the first connection end is located.

In some possible implementations, the metal mesh structure that makes up the ground plate is provided with a plurality of break points to uniformly heat the ground plate.

In some possible implementations, the radiator is an array formed by a plurality of microstrip line arrays, the first microstrip line array is formed by connecting a plurality of microstrip patches in a series feed mode, the microstrip patches are connected through microstrip lines, and the first microstrip line array is any microstrip line array in the microstrip line arrays.

In some possible implementations, the center-to-center spacing of adjacent microstrip patches in the plurality of microstrip patches is one waveguide wavelength, the length of a first patch is 1/2 of the waveguide wavelength, and the first patch is any microstrip patch in the plurality of microstrip patches, where the waveguide wavelength is associated with a speed of light in vacuum, an effective dielectric constant of the substrate, and a center frequency point of the antenna device.

In some possible implementations, the widths of the plurality of microstrip patches are different to meet the requirement of low side lobe distribution.

In some possible implementations, the widths of the plurality of microstrip patches decrease sequentially from a center position to both ends. The first microstrip line array is basically in axisymmetric distribution about the central line along the length direction.

In some possible implementations, the microstrip line arrays include a plurality of transmitting units, and a space between adjacent transmitting units is at least a wavelength corresponding to a center frequency of the antenna device; and/or the microstrip line arrays comprise a plurality of receiving units, and the distance between adjacent receiving units is at least 1/2 times of the wavelength.

In some possible implementations, the profile of the microstrip patch may be any of the following patterns:

rectangular, circular, oval, triangular.

In some possible implementations, the light transmittance of the antenna device meets a preset requirement.

In some possible implementations, the metal grid has a linewidth greater than or equal to 1 micron and the metal grid has a linewidth less than or equal to 20 microns.

In some possible implementations, the antenna device is applied to a vehicle.

In a second aspect, there is provided a vehicle comprising an antenna arrangement as described in the first aspect.

According to the antenna device, as the radiator and the grounding plate are both in the metal grid structure, good visible light transmittance can be maintained. The ground plate can be connected with a direct-current power supply, integrates an electric heating function, is favorable for solving the problem of glass icing and fogging in wet weather of rain and snow, keeps the sight of a driver clear, and is favorable for improving the driving safety. Meanwhile, based on the radiation principle of the microstrip antenna, the heating of the grounding plate can not influence the radiation performance of the microstrip antenna, and the antenna device can still keep high-precision detection and communication functions when heating.

Drawings

Fig. 1 is a schematic structural diagram of an antenna device according to an embodiment of the present application.

Fig. 2 a-2 b are schematic diagrams of one possible implementation of the metal mesh structure of the ground plate of fig. 1.

Fig. 3 is a schematic diagram of one possible implementation of the antenna arrangement of fig. 1.

Fig. 4 a-4 b are schematic diagrams of one possible implementation of the metal mesh structure of the radiator of fig. 3.

Fig. 5 is a schematic diagram of one possible implementation of the ground plate of fig. 3.

Fig. 6 is a schematic diagram of the reflection coefficient of the antenna device of fig. 3 as a function of frequency.

Fig. 7 is a schematic diagram of the radiation efficiency of the antenna device of fig. 3 as a function of frequency.

Fig. 8 is a schematic diagram of the radiation pattern of the antenna device of fig. 3 at 76.5 GHz.

Fig. 9 is a schematic diagram of a constituent unit/a partial constituent unit of a vehicle according to an embodiment of the present application.

Detailed Description

The following description of the technical solutions in the embodiments of the present application will be made clearly and completely with reference to the drawings in the embodiments of the present application, and it is apparent that the described embodiments are only some embodiments of the present application, not all embodiments.

With the rapid development of intelligent driving assistance technology, the requirements on the environment sensing capability of vehicles are increasingly increased. Millimeter wave radar is attracting attention due to its high operating frequency, large doppler shift, and small-sized antenna, which makes it possible to achieve miniaturization and integrated mounting of the millimeter wave radar system. At present, 24GHz and 77GHz are the millimeter wave radar working frequency bands of the global mainstream, but the detection distance of a 24GHz antenna is short, the area of a microstrip array antenna is larger, and the later integration of the whole radar is not facilitated. The 77GHz antenna has the advantage of a long detection distance, and generally the antenna size is inversely proportional to frequency, so the 77GHz array antenna is also smaller in size. Therefore, the vehicle-mounted 77GHz millimeter wave radar is one of the core sensors of the unmanned vehicle due to the characteristics of high-precision detection, small volume, light weight, long-distance measurement, moderate cost, strong anti-interference capability and the like.

On the one hand, the intelligent auxiliary driving automobile needs to integrate a forward detection radar antenna to realize detection of obstacles and vehicle distance, and on the other hand, needs to communicate with surrounding terminals and base stations to update the communication network condition in real time, so that a user can conveniently make better path planning. The vehicle radar antenna often adopts a millimeter wave antenna to achieve higher detection precision, and the forward detection radar also needs higher directivity and longer detection distance. The installation and configuration of antenna systems has been a challenge in practical vehicle manufacturing engineering. If the detection radar is placed inside the car body shell, the antenna loss is large, and the performance of the antenna is affected. In order to reduce the path loss and obtain a far radar detection distance and ensure the communication quality, the antenna position needs to be selected in a region which can be penetrated by visible light such as a front windshield, a car window or a rearview mirror. However, in wet weather conditions, the glass of the automobile is prone to fogging, which affects the vision of the driver and may cause traffic accidents.

At present, the technology of transparentizing millimeter wave radar antennas is mainly divided into two types. Firstly, a transparent metal oxide material such as Indium Tin Oxide (ITO) is used. The main radiator of the antenna is transparent, so that the antenna has high visible light trafficability. Millimeter wave radar antennas fabricated using transparent metal oxide materials such as ITO have problems of poor conductive performance and low radiation efficiency, which may cause a decrease in gain of the radar antenna, thereby affecting communication distance and communication quality. In addition, the thermal stability of the transparent metal oxide material is not clear. The other is a meshed metal radiator. So that visible light can pass through the grid, and has certain light transmittance. The material of the metal grid is usually copper, and the current processing technology has the problem that the line width and the line distance of the metal grid are large, so that the radiation efficiency and the transmittance can be reduced, and challenges are brought to the design of the millimeter wave antenna with fine size. Research on millimeter wave radar antennas with high permeability, defogging capability, and high-precision detection and communication functions is imperative.

Therefore, it is necessary to design a technical scheme of millimeter wave antenna with visible light transmittance and defogging capability.

It should be noted that the above-mentioned problem that the millimeter wave antenna does not have defogging capability affects the sight of the driver is only an example, and the embodiments of the present application may be applied to any type of scene where the millimeter wave antenna does not have defogging capability and affects the use.

Based on this, the embodiment of the application proposes an antenna device. Fig. 1 is a schematic diagram of an antenna device according to an embodiment of the present application. The antenna device of fig. 1 has visible light transmittance and electric heating capability, and is helpful for improving the performance and reliability of the intelligent auxiliary driving system and promoting the development of unmanned vehicles. The antenna device according to the embodiment of the present application will be described in detail with reference to fig. 1. As shown in fig. 1, the antenna device 100 may include: radiator 110, substrate 120 and ground plate 130.

The substrate 120 is composed of a light-transmitting material.

The substrate 120 is also called a dielectric substrate, a dielectric layer, or a dielectric layer, and is made of a material that has good light transmittance and is nonconductive. For example, the substrate 120 may be made of polyethylene terephthalate (PET), polycarbonate (PC), glass, cyclic olefin polymer (cyclo olefin polymer, COP), or SRF foam, etc.

The radiator 110 is located at one side of the substrate 120. Such as the radiator 110, is located on the upper side of the substrate 120. The radiator 110 is composed of a microstrip line formed based on a metal mesh structure, which contributes to obtaining a good visible light transmittance (i.e., high wave transmittance).

The microstrip line is a microwave transmission line formed by a single conductor strip arranged on a dielectric substrate, and is suitable for manufacturing a planar structure transmission line of a microwave integrated circuit. The grid structure is alternatively referred to as a mesh grid, lattice structure. The lattice structure may be a flat plate-like structure in which a plurality of bars (or wires) are arranged in a certain rule from two directions. In some embodiments, the grids in the metal grid structure may be rectangular. In other embodiments, the grids in the metal grid structure may be diamond-shaped, polygonal, other regular patterns, or irregular patterns.

Parameters of the metal grid structure may include grid line widths and spacings, or parameters of the metal grid structure may include grid line widths and apertures of the mesh (i.e., circumscribed circle diameters of the mesh). In some embodiments, the line width of the metal mesh may be, for example, greater than or equal to 1 micrometer (μm) and less than or equal to 20 μm. The effect that can not see by naked eyes can be realized to the normal narrower linewidth, reaches whole transparency, promotes pleasing to the eye effect.

The average value of the pore diameters of the meshes (namely the diameter of the circumcircle of the meshes) ranges from 50 μm to 2000 μm. For example, 50 μm, 60 μm, 70 μm, 80 μm, 90 μm, 100 μm, 200 μm, 300 μm, 400 μm, 500 μm, 600 μm, 700 μm, 800 μm, 900 μm, 1000 μm, 1100 μm, 1200 μm, etc. are possible. The adoption of the value range is beneficial to considering the electric heating temperature rising speed and the visual effect.

The ground plate 130 is located on the opposite side of the substrate 120 from the radiator 110, and the ground plate 130 has a metal mesh structure. The ground plate 130 is alternatively referred to as a ground plane and a reference plane. The ground plate 130 has a first connection end 131 and a second connection end 132, and the first connection end 131 and the second connection end 132 are used for connecting a direct current power supply to heat the ground plate 130.

The ground plate 130 has a metal mesh structure to help obtain better visible light transmittance. The grids in the metal grid structure are mutually connected to form a conductor, and the metal grid structure can have an electric heating function after being connected with a direct current power supply. The ground plane 130 of the microstrip antenna can shield the mutual coupling effect between the microstrip line (and microstrip patch) and other metal elements of the electronic device in which the antenna is mounted, thereby reducing interference. Alternatively, a direct current source may be connected to integrate the heating function. Therefore, the electric heating function of the antenna device is realized, the problem of glass fogging in wet weather of rain and snow is solved, the clear sight of a driver is kept, and the driving safety is improved. Based on the radiation principle of the microstrip antenna, the heating of the ground plate 130 does not affect the radiation performance of the microstrip antenna, so that the antenna device can still maintain high-precision detection and communication functions when heating.

In some implementations, the microstrip line of the radiator 110 may be grounded by a conductor connected to the ground plate 130, and the connection conductor may pass through the substrate 120 through a via.

In some implementations, the first connection end 131 is located at one end of the ground plate 130, and the second connection end 132 is located at an opposite end of the first connection end 131. I.e., the first connection end 131 is as far away from the second connection end 132 as possible, which contributes to uniform heating of the entire ground plate 130.

The grids in the metal grid structure are generally connected according to a certain rule, and a plurality of conductive paths may exist between the first connection terminal 131 and the second connection terminal 132. If a certain conducting path is shortest and the resistance is smallest, there may be a phenomenon that a part of the area of the ground plate 130 is heated well and the rest of the area is not heated. In some implementations, the metal mesh structure that makes up the ground plate 130 is provided with a plurality of break points to provide uniform ground plate heating. The provision of a plurality of break points allows current to flow uniformly in the metal mesh structure between the first connection terminal 131 and the second connection terminal 132 to heat the ground plate uniformly.

Fig. 2a is a schematic diagram of one possible implementation of the metal mesh structure of the ground plate of fig. 1. As shown in fig. 2a, the provision of a plurality of break points 210 allows for a uniform current flow in the metal grid structure to provide uniform ground plate heating. Fig. 2b is a schematic diagram of another possible implementation of the metal mesh structure of the ground plate of fig. 1. As shown in fig. 2b, the arrangement of the plurality of break points 210 allows for a uniform current flow in the metal grid structure to heat the ground plate uniformly the less effective paths of the conductor grid. It should be understood that the positions of the plurality of break points may be set according to a specific grid connection relationship in the metal grid structure, and the set break point positions may be different for different grid connection relationships. The position setting of the plurality of breakpoints in the embodiment of the present application is not particularly limited.

The microstrip line material constituting the radiator may be a metal material such as copper, silver, gold, or the like. The material of the ground plate 130 may be a metal material such as copper, silver, gold, etc. In some implementations, the microstrip line material comprising the radiator may be copper and the ground plate 130 may be copper. One side of the radiator 110 may be provided with a first copper oxide layer and one side of the ground plate 130 may be provided with a second copper oxide layer. For example, the antenna device 100 may be a first copper oxide layer, a radiator 110, a transparent substrate 120, a ground plate 130, and a second copper oxide layer sequentially from top to bottom.

In some implementations, the radiator 110 is an array consisting of a plurality of microstrip line arrays. The first microstrip line array is formed by connecting a plurality of microstrip patches in a series feed mode, the microstrip patches are connected through microstrip lines, and any one of the microstrip line arrays is used as the first microstrip line array. The plurality of microstrip patches may be, for example, 8, 10, 12, 16 microstrip patches, etc., which contributes to the improvement of the gain on the E-plane.

In some implementations, the center-to-center spacing of adjacent microstrip patches of the plurality of microstrip patches may be one waveguide wavelength, the length of the first patch is 1/2 waveguide wavelength, and the first patch is any microstrip patch of the plurality of microstrip patches. The waveguide wavelength is related to the speed of light in vacuum, the effective dielectric constant of the substrate and the center frequency point of the antenna arrangement. Helping to ensure that each microstrip patch excites in phase.

Waveguide wavelength lambda of a typical microstrip line _g The method comprises the following steps:

wherein c is the speed of light in vacuum, ε _e Is the effective dielectric constant, f, of the substrate 120 ₀ Is the center frequency of the antenna arrangement.

As a radar antenna, the side lobe level of the constant-amplitude distribution array is high, which is not beneficial to high-precision identification and imaging. Thus, a low side lobe profile design is necessary and the radiation conductance of the microstrip patch has a positive correlation with its width.

In some possible implementations, the widths of the plurality of microstrip patches are different to meet the requirement of low side lobe distribution.

The width of the microstrip patch generally determines the impedance and, in turn, the magnitude of the radiated current, with the wider the microstrip patch width, the greater the radiated current on it. In some possible implementations, the widths of the plurality of microstrip patches decrease sequentially from the center position to the two ends based on the excitation current amplitude ratio of the microstrip line array, which helps to obtain a reasonably low side lobe level. Preferably, the first microstrip line array is substantially axisymmetrically distributed about the center line along the length direction.

In some possible implementations, the profile of the microstrip patch may be any of the following patterns: rectangular, circular, oval, triangular, and other graphics.

In some possible implementations, the plurality of microstrip line arrays may include a plurality of transmitting units (or transmitting antennas), where a distance between any two adjacent transmitting units is at least greater than a wavelength corresponding to a center frequency of the antenna apparatus, e.g., 2λ, so as to help reduce interference between the transmitting units and improve isolation of the ports. And/or, the microstrip line arrays may include a plurality of receiving units (or receiving antennas), where the distance between any two adjacent receiving units is at least greater than 1/2 times of the wavelength corresponding to the center frequency, which is helpful for reducing interference between the receiving units and improving isolation of the ports. Wherein the center frequency f ₀ Corresponding wavelength λ=c/f ₀ . For example, the center frequency f ₀ May be 77GHz. It will be appreciated that space in electronic devices is often limited and that the spacing between adjacent transmitting units and/or adjacent receiving units should be set in view of isolation and space usage considerations.

In some possible implementations, the feed ports of the plurality of microstrip line arrays may be located at one end of the first microstrip line array. In other possible implementations, the feeding port may be located at a central position of the first microstrip line array.

In some possible implementations, the operating frequency band of the antenna device is a millimeter wave frequency band, which may be, for example, 24GHz and 77GHz.

In some possible implementations, the light transmittance of the antenna device meets a preset requirement. The light transmittance in the preset requirement is usually not less than 70%.

In some possible implementations, the antenna device is applied to a vehicle. Specifically, the antenna device can be applied to a region through which visible light such as a front windshield, a window, a rear view mirror, a lens, or the like of a vehicle can pass.

Preferably, the wire width of the metal grid may be 1-5 microns. The line width of the glass is usually less than 5 microns, which is invisible to naked eyes, is beneficial to improving the light transmittance, can be used for the position of a car window and the like on the premise of meeting the preset requirement of the light transmittance, and is heated to melt snow and ice.

The embodiment of the application provides an electrically heatable high-transmittance antenna device, and as a radiator and a grounding plate both adopt a metal grid structure, better visible light transmittance can be maintained. The ground plate can be connected with a direct-current power supply, integrates an electric heating function, is favorable for solving the problem of glass icing and fogging in wet weather of rain and snow, keeps the sight of a driver clear, and is favorable for improving the driving safety. Based on the radiation principle of the microstrip antenna, the heating of the grounding plate can not influence the radiation performance of the microstrip antenna, and the antenna device can still keep high-precision detection and communication functions when heating.

The antenna device according to the embodiments of the present application will be further described below with reference to some possible implementation manners of the embodiments of the present application.

Fig. 3 is a schematic diagram of one possible implementation of the antenna arrangement of fig. 1. In the embodiment of fig. 3, the metal mesh is manufactured by adopting the photoetching technology of the microstrip line, which is favorable for finely controlling the line width and the line distance of the metal line and is suitable for the transparent design of the millimeter wave antenna with fine structure. And further, the radiation efficiency and the transmittance of the antenna can be improved, and the communication distance and the communication quality of the radar antenna are enhanced. Meanwhile, the electric heating function is integrated, and the transparency design of the millimeter wave radar antenna with the integrated electric heating function is realized. Thus, the performance and reliability of the intelligent auxiliary driving system are improved, and the development of the unmanned vehicle is promoted. Specifically, as shown in the lower half of fig. 3, the antenna device 300 may include: radiator 110, substrate 120 and ground plate 130. The half of fig. 3 is a schematic diagram of the arrangement of the radiator 110 on the substrate 120.

The substrate 120 may be made of a material that has good PET light transmittance and is nonconductive. The relative dielectric constant is 3, the loss tangent is 0.001, and the thickness t can be 0.254mm.

The radiator 110 is located on the upper side of the substrate 120. The radiator 110 is composed of an array of microstrip lines, which are formed based on a metal mesh structure, i.e., metal gridding is adopted, which is helpful for obtaining better visible light transmittance (i.e., light transmittance).

The ground plate 130 is located at the lower side of the substrate 120 opposite to the radiator 110. The grounding plate 130 has a metal grid structure, i.e. adopts metal gridding, which is helpful for obtaining better visible light transmittance. The ground plate 130 has a first connection end and a second connection end, and the first connection end and the second connection end are used for connecting a direct current power supply to heat the ground plate 130.

The operating frequency band of the antenna device 300 is a millimeter wave band around 77GHz.

The radiator 110 is an antenna array composed of a plurality of microstrip line arrays, and the first microstrip line array is any one of the plurality of microstrip line arrays. The antenna form of the first microstrip line array is 1*8 microstrip series feed array. The first microstrip line array is formed by sequentially connecting 8 microstrip patches in series so as to obtain a wider beam on the E plane and improve the gain.

The E-plane, also called the electric plane, refers to a plane parallel to the direction of the electric field. The H-plane, also called the magnetic plane, refers to a plane parallel to the direction of the magnetic field. The E plane refers to a cross section of theta=90°, and the H plane refers to a cross section of phi=90°. The theta of the antenna is an angle in a pitching plane (vertical plane) ranging from 0 to 180 degrees; phi is the angle of the horizontal plane and ranges from 0 to 360 degrees.

In order to ensure that the antenna has side-firing directivity at the working frequency point, the phase center-to-center distance of each microstrip patch is controlled to be lambda _g To ensure in-phase excitation of each microstrip patch. Wherein lambda is _g Is the waveguide wavelength of the microstrip line,c is the speed of light in vacuum, ε _e Is the effective dielectric constant of the substrate, f ₀ Is the center frequency of the antenna. For example, at f ₀ Taking 77GHz epsilon _e Lambda when taking 3 _g About 2.25mm.

According to the radiation principle of the microstrip patch antenna, the length of each microstrip patch is approximately lambda _g /2. As shown in fig. 3, the length of the microstrip patchMay be l ₁ =1.05mm. Then the length of the stub (microstrip line) connecting adjacent microstrip patches is also approximately lambda _g 2, can be l _stub =1.26 mm, the width of the connecting stub may be w _stub =0.16 mm. In some embodiments, the last microstrip patch (i.e. the 8 th microstrip patch) is an open-ended, and the length of the last microstrip patch is optimized according to the simulation result ₈ =1.15 mm. The input port (i.e. feed port) can be a 50 ohm microstrip branch, and its length and width can be l respectively _port ＝0.62mm，w _port ＝0.36mm。

As a radar antenna, the side lobe level of the constant-amplitude distribution array is higher, which is not beneficial to high-precision identification and imaging, and a low side lobe distribution design is needed. The radiation conductance of the microstrip patch has a positive correlation with the width thereof, and in some implementations, the widths of the 8 microstrip patches can be determined in sequence based on the excitation current amplitude ratio of the microstrip line array according to design requirements: w (w) ₁ ＝0.36mm，w ₂ ＝0.72mm，w ₃ ＝1.12mm，w ₄ ＝1.38mm，w ₅ ＝1.38mm，w ₆ ＝1.22mm，w ₇ ＝0.64mm，w ₈ ＝0.23mm。

Millimeter wave radar antennas typically provide multiple transmit-receive antennas to improve detection accuracy. In fig. 3, six identical series-fed microstrip arrays (in the H plane) are arranged, two of which serve as transmitting units (TX), namely TX1 and TX2. For example, at the center frequency f ₀ When 77GHz is taken, the center frequency f ₀ The corresponding wavelength lambda is about 3.9mm. The distance between the two transmitting units is twice the wavelength lambda corresponding to the central frequency, and can be l _t =7.7mm, helps to reduce interference between transmit units, improves isolation of ports. The other four are receiving units (RX), namely RX1, RX2, RX3 and RX4. The receiving unit is alternatively called a receiving antenna. The spacing between adjacent receiving antennas can be half of the wavelength lambda corresponding to the center frequency, and the actual value can be l _r =1.9mm. In addition, the distance between the receiving antenna and the transmitting antenna can be d=12.5mm, so that the isolation of the port is improved. The two-transmit four-receive transceiver mode adopted in this embodiment is favorable for obtaining high resolutionRate and communication rate.

Fig. 4 a-4 b are schematic diagrams of one possible implementation of the metal mesh structure of the radiator of fig. 3. Fig. 4 a-4 b are also electron microscopy images of metal mesh structures used in embodiments of the present application. Parameters of the metal grid structure may include grid line width w _m And a distance of l _m . As shown in FIG. 4a, the metal mesh structure is composed of a plurality of regularly arranged metal thin lines intersecting perpendicularly, wherein the width of the metal thin lines is w _m =2.5 um, the spacing between two adjacent parallel thin lines is l _m ＝50um。

As shown in FIG. 4b, a metal mesh is attached on the PET substrate with a thickness t _m =0.5 um, pure copper, with conductivity σ=5.8x10 ⁷ s/m. The light transmittance of the metal mesh structure can be calculated from the duty cycle of the metal:

the antenna device is designed as a multi-layer structure, and sequentially comprises a metal grid of a radiator 110, a transparent substrate 120 and a metal grid of a grounding plate 130, wherein the total light transmittance is the product of the three components:

total light transmittance = light transmittance _{Metal grid} ² * Transmittance of light _PET

Wherein the transmittance of PET is generally 90%, and the transmittance can be calculated according to the size of the metal grid structure _{Metal grid} =90.25%, the estimated total light transmittance should be 73.1%. This can meet the normal driving requirement, reach the requirement of transparentization, and the requirement of light transmittance is not lower than 70%.

In addition, according to the size of the metal grid structure and the conductivity of copper, the sheet resistance of the metal grid structure can be calculated as follows:

substituting the actual value to obtain R _S =0.35 Ω/sq, less than 1 Ω/sq. This means that the material has good conductivity and is suitable for the transparent design of millimeter wave radar antenna.

Fig. 5 is a schematic diagram of one possible implementation of the ground plate in fig. 3. As shown in fig. 5, the ground plate 130 is a metal grid structure, the first connection end 131 is located at one end of the ground plate 130, and the second connection end 132 is located at an opposite end of the first connection end 131. The first connection end 131 is connected to the positive electrode of the dc power supply, and the second connection end 132 is connected to the negative electrode of the dc power supply. The metal mesh structure is composed of a plurality of regularly arranged metal thin wires which are vertically intersected, and the width of the metal thin wires can be w _m =2.5 um, the spacing between two adjacent parallel thin lines is l _m =50um. Wherein a plurality of break points (not shown in fig. 5) may be provided in the metal grid structure.

In this embodiment of the application, the heating mode of antenna device is to the floor layer of direct current power connection microstrip antenna, utilizes the heat loss that direct current signal produced to heat, can not influence millimeter wave signal's normal work.

The reflection coefficient and radiation efficiency curves of the antenna of the embodiment of fig. 3 along with the frequency change curve can be simulated by using simulation software (such as Ansoft HFSS), and the E-plane and H-plane patterns of the antenna device 300 are simulated to obtain the reflection coefficient and radiation efficiency curves. Fig. 6 is a schematic diagram of the reflection coefficient of the antenna device of fig. 3 as a function of frequency. Fig. 7 is a schematic diagram of the radiation efficiency of the antenna device of fig. 3 as a function of frequency. It should be noted that the simulation result is obtained by feeding only the first transmitting antenna (RX 1). As can be seen from fig. 6, the reflection coefficient of the antenna (RX 1) is less than-10 dB in the 76.16GHz-77.7GHz band, indicating good impedance matching performance. As can be seen from fig. 7, the radiation efficiency of the antenna (RX 1) is higher than 72% in the 76.17GHz-77.85GHz frequency band, which indicates that the antenna has good radiation performance and the metal mesh structure has small loss.

Fig. 8 is a schematic diagram of the radiation pattern of the antenna device of fig. 3 at 76.5 GHz. As shown in the left part of fig. 8, the 3dB beam width of the antenna device in the E-plane radiation pattern of the 76.5GHz frequency point is about 14.5 °, and the side lobe is lower than-23 dB, which makes it possible to have high detection accuracy. As shown in the right part of fig. 8, the 6dB beam width in the H-plane radiation pattern is 100 °, which makes it possible to have a wide detection range in the horizontal plane. Meanwhile, the gain of the antenna at a frequency point of 76.5GHz is 13.63dBi, so that the antenna has good detection depth.

In the antenna device of the embodiment of the application, the radiator and the grounding plate both adopt metal grid structures, so that good visible light transmittance can be maintained. The ground plate can be connected with a direct-current power supply, integrates an electric heating function, is favorable for solving the problem of glass icing and fogging in wet weather of rain and snow, keeps the sight of a driver clear, and is favorable for improving the driving safety. Based on the radiation principle of the microstrip antenna, the heating of the grounding plate can not influence the radiation performance of the microstrip antenna, and the antenna device can still keep high-precision detection and communication functions when heating. According to the embodiment of the application, the width of the microstrip patch is adjusted by optimizing the layout of the metal gridded microstrip structure and the antenna, so that high radiation efficiency, good impedance matching and radiation performance can be realized. The millimeter wave antenna design of this application embodiment brings higher performance and reliability for intelligent auxiliary driving system, helps promoting unmanned vehicle's development.

Fig. 9 is a schematic diagram of a constituent unit/a partial constituent unit of a vehicle according to an embodiment of the present application. As shown in fig. 9, a vehicle 900 may include an antenna device 910 as described in any of the foregoing.

Specifically, the antenna device 910 may be applied to an area of the vehicle 900 through which visible light can pass, such as a front windshield, a window, a rear view mirror, and a lens.

In the above embodiments, it may be implemented in whole or in part by software, hardware, firmware, or any other combination. When implemented in software, may be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When loaded and executed on a computer, produces a flow or function in accordance with embodiments of the present disclosure, in whole or in part. The computer may be a general purpose computer, a special purpose computer, a computer network, or other programmable apparatus. The computer instructions may be stored in a machine-readable storage medium or transmitted from one machine-readable storage medium to another machine-readable storage medium, for example, the computer instructions may be transmitted from one website, computer, server, or data center to another website, computer, server, or data center by a wired (e.g., coaxial cable, fiber optic, digital subscriber line (digital subscriber line, DSL)) or wireless (e.g., infrared, wireless, microwave, etc.). The machine-readable storage medium may be any available medium that can be accessed by a computer or a data storage device including one or more servers, data centers, etc. integrated with the available medium. The usable medium may be a magnetic medium (e.g., a floppy disk, a hard disk, a magnetic tape), an optical medium (e.g., a digital video disc (digital video disc, DVD)), or a semiconductor medium (e.g., a Solid State Disk (SSD)), or the like.

Those of ordinary skill in the art will appreciate that the elements and algorithm steps described in connection with the embodiments disclosed herein can be implemented as electronic hardware, or combinations of computer software and electronic hardware. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the solution. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present disclosure.

It should be understood that, in various embodiments of the present application, "first," "second," etc. are used to distinguish between different objects, and not to describe a specific order, the size of the sequence numbers of each process described above does not mean that the order of execution should not be construed as to imply that the order of execution of each process should be determined by its function and inherent logic, but should not be construed as limiting the implementation of the embodiments of the present application.

In the several embodiments provided in the present disclosure, it should be understood that the disclosed systems, devices, and methods may be implemented in other manners. For example, the apparatus embodiments described above are merely illustrative, e.g., the division of the units is merely a logical function division, and there may be additional divisions when actually implemented, e.g., multiple units or components may be combined or integrated into another system, or some features may be omitted or not performed. Alternatively, the coupling or direct coupling or communication connection shown or discussed with each other may be an indirect coupling or communication connection via some interfaces, devices or units, which may be in electrical, mechanical or other form.

In several embodiments provided herein, it will be understood that when a portion is referred to as being "connected" or "connected" to another portion, it means that the portion can be "directly connected" or "electrically connected" while another element is interposed therebetween. In addition, the term "connected" also means that the portions are "physically connected" as well as "wirelessly connected". In addition, when a portion is referred to as "comprising" an element, it is meant that the portion may include the other element without excluding the other element, unless otherwise stated.

The units described as separate units may or may not be physically separate, and units shown as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

In addition, each functional unit in each embodiment of the present disclosure may be integrated in one processing unit, or each unit may exist alone physically, or two or more units may be integrated in one unit.

The foregoing is merely specific embodiments of the disclosure, but the protection scope of the disclosure is not limited thereto, and any person skilled in the art can easily think about changes or substitutions within the technical scope of the disclosure, and it is intended to cover the scope of the disclosure. Therefore, the protection scope of the present disclosure shall be subject to the protection scope of the claims.

Claims (11)

1. An antenna device, comprising:

a substrate composed of a light-transmitting material;

the radiator is positioned on one side of the substrate and is composed of microstrip lines, and the microstrip lines are formed based on a metal grid structure;

the grounding plate is positioned on one side of the substrate opposite to the radiator, the grounding plate is of a metal grid structure, the grounding plate is provided with a first connecting end and a second connecting end, and the first connecting end and the second connecting end are used for being connected with a direct-current power supply to heat the grounding plate.

2. The antenna device according to claim 1, wherein the first connection end is located at one end of the ground plate, the second connection end is located at an opposite end of the end where the first connection end is located, and/or a metal mesh structure constituting the ground plate is provided with a plurality of break points so as to uniformly heat the ground plate.

3. The antenna device according to claim 1, wherein the radiator is an array composed of a plurality of microstrip line arrays, a first microstrip line array is composed of a plurality of microstrip patches connected in series feed, and the first microstrip line array is any one of the plurality of microstrip line arrays.

4. The antenna device of claim 3, wherein a pitch of adjacent microstrip patches in the plurality of microstrip patches is one waveguide wavelength, a length of a first patch is 1/2 waveguide wavelength, the first patch is any microstrip patch in the plurality of microstrip patches, and the waveguide wavelength is associated with a speed of light in vacuum, an effective dielectric constant of the substrate, and a center frequency point of the antenna device.

5. The antenna device of claim 4, wherein the widths of the plurality of microstrip patches are different.

6. The antenna device according to claim 5, wherein the widths of the plurality of microstrip patches decrease sequentially from a center position to both ends.

7. The antenna device according to claim 4, wherein the profile of the microstrip patch may be any of the following patterns:

rectangular, circular, oval, triangular.

8. The antenna device according to any one of claims 1-7, characterized in that the light transmittance of the antenna device meets a preset requirement.

9. The antenna device according to any one of claims 1-7, wherein a line width of the metal grid is greater than or equal to 1 micron and a line width of the metal grid is less than or equal to 20 microns.

10. The antenna device according to any one of claims 1-7, characterized in that the antenna device is applied to a vehicle.

11. A vehicle comprising an antenna arrangement as claimed in any one of claims 1-10.