Double-layered complementary frequency selective surface with multi-band communication signal anti-reflection function

Abstract

The application provides a double-layer complementary frequency selective surface with multi-band communication signal antireflection function, comprising a first metal coating surface and a second metal coating surface arranged in sequence; wherein the first metal coating surface has a first frequency selective surface; the second metal coating surface has a second frequency selective surface; the pattern of the first frequency selective surface and the pattern of the second frequency selective surface are complementary patterns. In the application, the frequency selective surface with double-layer complementary structure can realize high transmittance of electromagnetic signals at a target frequency band; the frequency selective surface based on double-layer complementarity realizes certain large-angle incidence and polarization stability. The pattern of the first frequency selective surface and the pattern of the second frequency selective surface are complementary patterns, so that the frequency selective surface with double-layer complementary structure can realize high transmittance of electromagnetic waves at a target frequency band while retaining the original single-layer metal coating function (such as low radiation and power generation) as much as possible.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of wireless communication, and more particularly relates to a double-layer complementary frequency selective surface with a multi-band communication signal anti-reflection function. BACKGROUND

[0002] With the emphasis on sustainable development and the progress of industry technology, low-emissivity building glass, power-generating glass and low-emissivity automotive laminated glass are widely used. Low-emissivity building glass reduces indoor and outdoor heat transfer through coating, helping to save energy; power-generating glass can efficiently convert solar energy into electrical energy, which is green and environmentally friendly; low-emissivity automotive laminated glass can reduce the exchange of heat radiation in the car, improving the energy utilization efficiency of the car.

[0003] However, with the rapid development of Internet of Things technology, high-frequency signals such as 5G are widely used, and the problem of signal attenuation in the metal coating of low-emissivity building glass, power-generating glass and low-emissivity automotive laminated glass is increasingly prominent. The metal coating of low-emissivity building glass hinders the interaction of indoor and outdoor communication signals, causing poor network connection of smart home devices connected by external base stations and other signals. The metal coating of low-emissivity automotive laminated glass interrupts or delays the Internet of Vehicles signal, affecting functions such as intelligent driving. 5G high-frequency signals have a shorter wavelength and are easily reflected, scattered and absorbed by metal coatings, increasing the path loss of signals, significantly attenuating signals and seriously affecting communication quality.

[0004] Currently, existing technologies to improve the signal transmission rate of metal coatings often damage the metal thermal insulation coating, resulting in a loss of the original functions of the metal coating, such as low-emissivity and power generation. There is an urgent need for innovative technology to break through this difficulty. SUMMARY

[0005] The purpose of the embodiments of the present application is to provide a frequency selective surface with a double-layer complementary structure, specifically to convert the original single-layer metal coating into a frequency selective surface with a double-layer complementary structure, to solve the technical problem of the existing technology that the original function of the metal coating is lost and the signal transmission rate is difficult to be considered.

[0006] To achieve the above purpose, the technical solution adopted by the present application is to provide a frequency selective surface with a double-layer complementary structure, comprising a first metal coating surface and a second metal coating surface; wherein the first metal coating surface has a first frequency selective surface; the second metal coating surface has a second frequency selective surface; the pattern of the first frequency selective surface and the pattern of the second frequency selective surface are complementary patterns.

[0007] Further, the first frequency selective surface is of aperture type or patch type; the second frequency selective surface is of aperture type or patch type.

[0008] Further, the first frequency selective surface comprises a plurality of first structural units arranged in an array; and the second frequency selective surface comprises a plurality of second structural units arranged in an array.

[0009] Further, the first structural unit is a center-symmetric figure, including a circle, a hexagon, and a square; and the second structural unit is also a center-symmetric figure, including a circle, a hexagon, and a square.

[0010] As an optional solution, the first structural unit is a hexagonal patch unit, a length d1 of the hexagonal patch unit ranges from 0.1 mm to 3 mm; and a gap w1 between adjacent hexagonal patch units ranges from 1 um to 1 mm.

[0011] The second structural unit is a hexagonal strip unit, a length d2 of the hexagonal strip unit ranges from 0.1 mm to 3 mm; and a line width w2 of the hexagonal strip unit ranges from 1 um to 1 mm.

[0012] Further, in the hexagonal strip unit, a midpoint of each side of the hexagon is provided with a partition, and a width w3 of the partition ranges from 1 um to 1 mm.

[0013] Further, when d1 = d2 and w1 = w2, the first frequency selective surface and the second frequency selective surface are complementary, and are equivalent to a single-layer metal coating; the partition is formed by etching treatment, and an area of the single-layer metal coating etched away accounts for a percentage of a total area of the single-layer metal coating, and the percentage satisfies the following relationship:

[0014] .

[0015] As another optional solution, the first structural unit is a first square patch FSS unit, the first square patch FSS unit has four regions of upper left, lower left, upper right, and lower right which are adjacent to each other in pairs; and the first square patch FSS unit comprises two first square patches, the two first square patches are located in the lower left region and the upper right region respectively.

[0016] The second structural unit is a second square patch FSS unit, the second square patch FSS unit has four regions of upper left, lower left, upper right, and lower right which are adjacent to each other in pairs; and the second square patch FSS unit comprises two second square patches, the two second square patches are located in the upper left region and the lower right region respectively.

[0017] Further, a length a1 of the first square patch ranges from 100 um to 1.5 mm; and a length a2 of the second square patch ranges from 100 um to 1.5 mm.

[0018] Further, the first square patch has a first etching area at four vertices thereof; the first etching area is in the shape of a quarter circle with the vertex of the first square patch as the center and r1 as the radius;

[0019] The second square patch has a second etching area at four vertices thereof; the second etching area is in the shape of a quarter circle with the vertex of the second square patch as the center and r2 as the radius.

[0020] Further, when a1 = a2 and r1 = r2, the first square patch FSS unit and the second square patch FSS unit are complementary, and are equivalent to a single-layer metal coating; the area percentage of the first etching area and the second etching area in the total single-layer metal coating area satisfies the following relationship:

[0021] .

[0022] For the double-layer complementary frequency selective surface with multi-band communication signal anti-reflection function provided in the present application, the following anti-reflection target frequency bands are included:

[0023] Operators of mobile 5G and 6G:

[0024] China Mobile 5G, (n41) 2515-2675 MHz

[0025] China Telecom 5G, (n78) 3400-3500 MHz

[0026] China Unicom 5G, (n78) 3500-3600 MHz

[0027] China Telecom, China Unicom and China Radio jointly own (n77) band 3300-3400 MHz

[0028] The Radio Frequency Division Regulations clearly states that the Ministry of Industry and Information Technology will be the first in the world to divide the 6GHz (6425-7125MHz) 6775MHz band or part of the band for IMT (5G / 6G) system, and adds high-frequency bands such as millimeter wave band 24.75-27.5GHz (n258).

[0029] B1 band of Beidou civilian navigation: 1561.098 MHz (1559.052-1591.788 MHz).

[0030] Wifi: 2.4GHz band (2.4-2.4835GHz) can be used for broadband wireless access (including wireless LAN), Bluetooth, point-to-point transmission and other radio communication systems. 5GHz band (5.15-5.85GHz) can be used for broadband wireless access (including wireless LAN), point-to-point transmission, electronic non-stop toll collection (ETC) and other radio communication systems.

[0031] Vehicle-mounted communication: 5905-5925MHz band (5915MHz). Use: planned for Internet of Vehicles (smart connected vehicles) direct communication, supporting direct communication and information exchange between vehicles (V2V), roads (V2I), and people (V2P).

[0032] The double-layer complementary frequency selective surface with multi-band communication signal antireflection function provided by the application has the advantages that: compared with the prior art, in the application, the frequency selective surface with a double-layer complementary structure can achieve high transmittance of electromagnetic signals at a target frequency band; the designed frequency selective surface based on a double-layer complement realizes a certain large-angle incidence and polarization stability. By setting the first frequency selective surface and the second frequency selective surface with complementary structures, the functions of the original single-layer metal coating can be retained as much as possible; the patterns of the first frequency selective surface and the second frequency selective surface are complementary patterns, so that the frequency selective surface with a double-layer complementary structure can achieve high transmittance of electromagnetic waves at a target frequency band while retaining the functions of the original single-layer metal coating (such as low radiation and power generation) as much as possible. BRIEF DESCRIPTION OF DRAWINGS

[0033] In order to more clearly illustrate the technical solutions in the embodiments of the application, the drawings needed in the embodiments or the prior art description will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the application, and other drawings can be obtained by those skilled in the art without creative labor.

[0034] Figure 1 The hexagonal patch FSS unit structure with multi-band communication signal antireflection function provided by the embodiments of the application is shown in the schematic diagram.

[0035] Figure 2 The structure schematic diagram of the hexagonal strip FSS unit with multi-band communication signal antireflection function provided by the embodiments of the application is shown in the schematic diagram.

[0036] Figure 3 The top view of the hexagonal patch FSS unit and the hexagonal strip FSS unit in the double-layer complementary frequency selective surface with multi-band communication signal antireflection function provided by the embodiments of the application is shown in the schematic diagram.

[0037] Figure 4 The explosion structure schematic diagram (hexagonal) of the low radiation automobile laminated glass with multi-band communication signal anti-reflection function provided by the embodiment of the present application;

[0038] Figure 5 The s parameter simulation result (hexagonal) of the low radiation automobile laminated glass with multi-band communication signal anti-reflection function provided by the embodiment of the present application;

[0039] Figure 6 The second square patch FSS unit structure schematic diagram with multi-band communication signal anti-reflection function provided by the embodiment of the present application;

[0040] Figure 7 The first square patch FSS unit structure schematic diagram with multi-band communication signal anti-reflection function provided by the embodiment of the present application;

[0041] Figure 8 The explosion structure schematic diagram (square) of the low radiation automobile laminated glass with multi-band communication signal anti-reflection function provided by the embodiment of the present application;

[0042] Figure 9 The s parameter simulation result (square) of the low radiation automobile laminated glass with multi-band communication signal anti-reflection function provided by the embodiment of the present application.

[0043] In the drawings, various reference signs represent:

[0044] 100 - first glass layer;

[0045] 200 - first metal coating surface; 201 - hexagonal patch unit; 202 - first square patch; 221 - first etching area;

[0046] 300 - PVB layer;

[0047] 400 - second metal coating surface; 401 - hexagonal strip unit; 411 - partition; 402 - second square patch; 421 - second etching area;

[0048] 500 - second glass layer. DETAILED DESCRIPTION

[0049] In order to make the technical problems, technical solutions and beneficial effects of the present application clearer, the present application will be further described in detail below in combination with the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and do not limit the present application.

[0050] It should be noted that when an element is referred to as being "fixed" or "set" on another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or indirectly connected to the other element.

[0051] It should be understood that the terms "length", "width", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.

[0052] In addition, the terms "first", "second" are only for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "multiple" is two or more, unless otherwise specifically limited.

[0053] In the present embodiment, the communication in the low-radiation automotive glass scenario is taken as an example for illustration.

[0054] Please refer to Figure 4 and Figure 8 , the low-radiation automotive laminated glass with multi-band communication signal antireflection function provided by the embodiments of the present application will be described. The low-radiation automotive laminated glass with multi-band communication signal antireflection function comprises a first glass layer 100, a first metal coating surface 200, a PVB layer 300, a second metal coating surface 400 and a second glass layer 500 arranged in sequence; wherein the first metal coating surface 200 has a first frequency selective surface; the second metal coating surface 400 has a second frequency selective surface; the pattern of the first frequency selective surface and the pattern of the second frequency selective surface are complementary patterns.

[0055] The low-radiation automotive laminated glass with multi-band communication signal antireflection function provided by the present application, compared with the prior art, in the embodiments of the present application, by setting the first heat insulation layer and the second heat insulation layer, the heat insulation effect of the low-radiation automotive laminated glass can be improved; by setting the first frequency selective surface and the second frequency selective surface, high transmittance of electromagnetic signals at the target frequency band can be realized; the pattern of the first frequency selective surface and the pattern of the second frequency selective surface are complementary patterns, so that the low-radiation automotive laminated glass can realize high transmittance of electromagnetic waves at the target frequency band on the premise of retaining the heat insulation effect of the low-radiation automotive laminated glass.

[0056] In this embodiment, the first glass layer 100 and the second glass layer 500 are both made of white glass or super white glass, which has high visible light transparency and durability, and can effectively ensure the clarity and safety of the driving field of view. At the same time, the selection of white glass or super white glass can further improve the overall aesthetics of the laminated glass, which meets the pursuit of modern cars for appearance design. In addition, the thickness and strength of the first glass layer 100 and the second glass layer 500 are carefully designed to ensure that the laminated glass has sufficient strength and toughness when subjected to external force impact, thereby protecting the safety of passengers in the vehicle.

[0057] In this embodiment, the PVB layer 300 is made of PVB film, i.e. polyvinyl butyral film, which has good toughness and adhesion, and can firmly bond the first glass layer 100 and the second glass layer 500 together to form a whole. At the same time, the PVB film also has certain sound insulation and heat insulation effect, which can further improve the performance of the automotive laminated glass. When subjected to external force impact, the PVB film can effectively absorb and disperse impact energy, preventing glass fragments from flying, thereby protecting the safety of passengers in the vehicle.

[0058] In this embodiment, the first metal coating surface 200 and the second metal coating surface 400 both use transparent metal heat insulation materials, which are composed of multiple layers of metal and metal oxide deposited on a dielectric substrate, and have low emissivity and good heat insulation. Their main function is to reflect infrared radiation and prevent heat from entering the vehicle, thereby reducing air conditioning energy consumption and improving the energy efficiency of the vehicle.

[0059] It can be understood that the first metal coating surface 200 and the second metal coating surface 400 have internal metal layers that can reflect infrared radiation and shield electromagnetic waves. A large number of stacked high-conductivity metal layers inevitably attenuate electromagnetic signals in the communication frequency band. Therefore, the present application is provided with a first frequency selective surface and a second frequency selective surface. The first frequency selective surface is formed by laser etching the first metal coating surface 200, which can play a role in signal transmission. The second frequency selective surface is formed by laser etching the second metal coating surface 400, which also can play a role in signal transmission.

[0060] It can be understood that the frequency selective surface (FSS) is a two-dimensional periodic structure, which is usually formed by metal patches or aperture units arranged on a dielectric substrate according to a certain rule. The electromagnetic signal induces the resonance effect of the FSS when it is transmitted to the FSS, thereby enhancing the transmission of electromagnetic waves and reducing the attenuation of electromagnetic signals. In this application, the first frequency selective surface and the second frequency selective surface are respectively arranged on the first metal coating surface 200 and the second metal coating surface 400, and through careful design of the pattern and arrangement, they can achieve high transmittance of electromagnetic waves of the target frequency band while retaining the heat insulation effect.

[0061] In an embodiment of the present application, the first frequency selective surface is of aperture type or patch type; the second frequency selective surface is of aperture type or patch type.

[0062] Specifically, when the first frequency selective surface is of aperture type, it forms a series of regularly arranged apertures on the first metal coating surface 200, which can allow electromagnetic waves of a specific frequency to penetrate while blocking electromagnetic waves of other frequencies, thereby achieving the effect of signal transmittance. When the first frequency selective surface is of patch type, it forms a series of metal patches on the first metal coating surface 200, which can also induce the resonance effect of the FSS to enhance the transmission of electromagnetic waves of a specific frequency. The design principle of the second frequency selective surface of aperture type or patch type is the same as that of the first frequency selective surface, but the frequency band may be different to meet the needs of signal transmittance of different frequency bands.

[0063] In an embodiment of the present application, the first frequency selective surface includes a plurality of first structure units arranged in an array; the second frequency selective surface includes a plurality of second structure units arranged in an array.

[0064] In this embodiment, each first structure unit and second structure unit is a carefully designed microstructure, which is designed to interact with electromagnetic waves of a specific frequency band. For the first frequency selective surface, the first structure units may be apertures or patches of different shapes, sizes and arrangement modes to achieve efficient transmission of electromagnetic waves of a specific frequency band. The design of these structure units fully considers the wavelength, polarization direction and other factors of electromagnetic waves to ensure that the heat insulation performance is retained while the signal strength of the target frequency band is maximized.

[0065] The second structure units of the second frequency selective surface may be designed for another frequency band, and their shapes, sizes and arrangement modes may be different from those of the first structure units to meet the needs of signal transmittance of different frequency bands. Through such design, the automobile laminated glass of the present application can achieve efficient signal transmission in multiple frequency bands, providing a strong guarantee for the normal work of the vehicle-mounted communication equipment.

[0066] In an embodiment of the present application, the shape of the first structural unit includes a circle, a hexagon, and a square; the shape of the second structural unit includes a circle, a hexagon, and a square.

[0067] In the present embodiment, the first structural units of the circle, the hexagon, and the square are ingeniously arranged on the first frequency selective surface to form regular or irregular patterns, which further enhance the interaction with electromagnetic waves of a specific frequency band. Similarly, the second structural units of the circle, the hexagon, and the square on the second frequency selective surface are also carefully laid out to ensure that they can effectively enhance signals for another frequency band. Through the combination design of multiple shapes and sizes of structural units, the automobile laminated glass of the present application can achieve efficient communication signal transmission in a wider frequency band range, not only improving the performance of the vehicle communication equipment, but also ensuring smooth communication during driving. In addition, this design also takes into account the aesthetics and practicality, so that the automobile laminated glass not only maintains the original function, but also better meets the aesthetic needs of modern cars.

[0068] In an embodiment of the present application, please refer to Figure 4 and Figure 8 , the thickness h1 of the first glass layer 100 ranges from 0.9mm to 6mm; the thickness of the first metal coating surface 200 is h2; the thickness h3 of the PVB layer 300 ranges from 0.38mm to 0.76mm; the thickness of the second metal coating surface 400 is h4, and the thickness h5 of the second glass layer 500 ranges from 0.9mm to 6mm.

[0069] In the present embodiment, by precisely controlling the thickness of the first glass layer 100, the PVB layer 300, and the second glass layer 500, we further optimize the overall performance and signal transmission efficiency of the automobile laminated glass. Specifically, the first glass layer 100 as the outer layer, the selection of its thickness h1 not only concerns the strength and impact resistance of the glass, but also affects the propagation characteristics of electromagnetic waves therein. Similarly, the PVB layer 300 as the interlayer material, the precise regulation of its thickness h3 is crucial to maintaining the integrity of the glass and the signal transmission effect. And the second glass layer 500, as the layer directly in contact with the vehicle environment, the selection of its thickness h5 ensures safety while also taking into account the quality of signal transmission. This fine regulation of the thickness of the glass layer enables the automobile laminated glass of the present application to achieve more balanced and efficient signal transmission at different frequency bands, thereby meeting the high requirements of modern cars for communication performance.

[0070] Embodiment 1

[0071] In an embodiment of the present application, please refer to Figure 1 andFigure 2 The first structural unit is a hexagonal patch unit 201, the length of the side of the hexagonal patch unit 201 d1 is in the range of 0.1mm to 3mm; the gap w1 between adjacent hexagonal patch units 201 is in the range of 1um to 1mm; the second structural unit is a hexagonal strip unit 401, the length of the side of the hexagonal strip unit 401 d2 is in the range of 0.1mm to 3mm; the line width w2 of the hexagonal strip unit 401 is in the range of 1um to 1mm.

[0072] In this embodiment, by reasonably designing the geometric parameters of the first structural unit and the second structural unit, the optimized anti-transmission effect of the multi-band communication signal is realized. Specifically, the selection of the lengths of the sides d1 and d2 of the hexagonal patch unit 201 and the hexagonal strip unit 401 not only affects the resonant frequency of each unit, but also further widens the frequency range of signal anti-transmission through mutual coupling. At the same time, the precise regulation of the gap w1 between adjacent hexagonal patch units 201 and the line width w2 of the hexagonal strip unit 401 helps to reduce the loss of the signal in the transmission process and improve the transmission efficiency of the signal. This fine structural design enables the automobile laminated glass of the present application to realize efficient and stable signal transmission in multiple frequency bands, thereby meeting the high requirements of modern automobiles for communication performance.

[0073] In an embodiment of the present application, please refer to Figure 2 and Figure 3 In the hexagonal strip unit 401, a partition 411 is arranged at the midpoint of each side of the hexagon, and the width w3 of the partition 411 is in the range of 1um to 1mm.

[0074] In this embodiment, the arrangement of the partition 411 further enhances the structural flexibility of the hexagonal strip unit 401, enabling it to more flexibly adjust the response to signals of different frequency bands. Specifically, the precise control of the width w3 of the partition 411 not only affects the resonant characteristics of the hexagonal strip unit 401 itself, but also optimizes the anti-transmission effect of the signal in a specific frequency band by changing the electric field distribution inside the unit. This design enables the hexagonal strip unit 401 to realize efficient signal transmission in a wider frequency range, further improving the overall communication performance of the automobile laminated glass. At the same time, the presence of the partition 411 helps to reduce the crosstalk between signals in the unit, ensuring the stability and clarity of signal transmission. Therefore, by introducing the partition 411 structure, the automobile laminated glass of the present application realizes more fine regulation and optimization of multi-band communication signals.

[0075] In an embodiment of the present application, when d1=d2, w1=w2, the first metal coating surface 200 and the second metal coating surface 400 are complementary, equivalent to a single-layer thermal insulation coating; the partition 411 is formed by etching treatment, and the area of the etched single-layer thermal insulation coating accounts for a percentage of the total area of the single-layer thermal insulation coating, which satisfies the following relationship:

[0076] (1-1)

[0077] In this embodiment, when the etching treatment satisfies the above relationship, the thermal insulation performance and the communication signal transmittance effect can be effectively balanced. Specifically, by accurately controlling the area of the etched single-layer thermal insulation coating, the good thermal insulation performance of the automotive laminated glass is maintained, and the efficient transmission of the communication signal in the required frequency band is ensured. This design strategy not only improves the functionality of the automotive laminated glass, but also takes into account the aesthetics and practicality. In addition, the structure of the partition 411 formed by etching treatment further enhances the structural stability of the hexagonal strip-shaped unit 401, so that it can still maintain good performance in complex and variable communication environments. Therefore, the automotive laminated glass of the present application realizes the dual improvement of thermal insulation performance and communication signal transmittance effect by optimizing the etching treatment parameters.

[0078] In this embodiment, the first metal coating surface 200 can be deposited on one side of the first glass layer 100 by magnetron sputtering technology, and the second metal coating surface 400 can be deposited on one side of the second glass layer 500 by magnetron sputtering technology. The first glass layer 100 and the first metal coating surface 200, and the second glass layer 500 and the second metal coating surface 400 are laminated into a whole low-emissivity automotive laminated glass through the PVB layer 300. And through laser etching or mask technology, the first metal coating surface 200 is converted into an array of hexagonal patch elements 201. The second metal coating surface 400 is converted into an array of hexagonal strip-shaped units 401.

[0079] Specifically, the stacking order, thickness and electromagnetic characteristic parameters of each component structure of the low-emissivity automotive laminated glass are shown in Table 1.

[0080] Table 1

[0081]

[0082] In this embodiment, d1=d2=451 microns, w1=w2=50 microns, and w3=20 microns are set.

[0083] The simulation software CST microwave studio is used for simulation, and the effect of multi-band communication signal transmittance is shown in Table 2. The results show that the designed frequency selective surface based on double-layer complementarity realizes certain large-angle incidence and polarization stability.

[0084] Table 2

[0085]

[0086] Table 3 summarizes the signal transmission results of the designed hexagonal double-layer complementary structure at multiple frequency bands such as operator, satellite navigation, millimeter wave, etc. at normal incidence.

[0087] Table 3

[0088]

[0089] In order to further analyze the multi-band signal antireflection effect of the low-emissivity automotive laminated glass with complementary first frequency selective surface and second frequency selective surface, the S parameter simulation results of the low-emissivity automotive laminated glass implemented in the present application are compared with bare glass without thermal barrier coating and automotive laminated glass with single layer of unetched FSS thermal barrier coating, and the results are shown in Figure 5

[0090] Among them, the structure of the bare glass without thermal barrier coating from the outside of the vehicle to the inside of the vehicle is: first glass layer / PVB layer / second glass layer; the automotive laminated glass with single layer of unetched FSS thermal barrier coating from the outside of the vehicle to the inside of the vehicle is: first glass layer / PVB layer / thermal barrier coating / second glass layer.

[0091] According to the simulation results of Figure 5 , in the range of 0 to 35 GHz, the insertion loss of the automotive laminated glass with single layer of unetched FSS thermal barrier coating is in the range of -34.6 dB to -45.6 dB. While for the low-emissivity automotive laminated glass implemented in the present application, the insertion loss is in the range of -0.73 dB to -5.2 dB. It can be seen that the corresponding insertion loss of the low-emissivity automotive laminated glass implemented in the present application is improved by about -30 dB to -40 dB compared with the automotive laminated glass with single layer of unetched FSS thermal barrier coating.

[0092] According to the simulation results of Figure 5 , at normal incidence, the insertion loss of the low-emissivity automotive laminated glass implemented in the present application and the insertion loss of the bare glass without thermal barrier coating are less different in the range of 0 to 25 GHz. In the range of 0 to 40 GHz, for the bare glass without thermal barrier coating, the insertion loss is within about -3 dB, and in the range of 20 GHz to 25 GHz, the insertion loss is greater than -3 dB. While in the range of 0 to 25 GHz, the insertion loss of the low-emissivity automotive laminated glass implemented in the present application is within -4 dB. After 25 GHz, the insertion loss of the low-emissivity automotive laminated glass implemented in the present application shows an increasing trend compared with the bare glass without thermal barrier coating, but overall is within -8 dB.

[0093] ​It is shown that the shielding effect of the low-emissivity automotive laminated glass with the first frequency selective surface and the second frequency selective surface which are complementary to each other on the communication signal is less different from that of the bare glass without the thermal barrier coating at 0-25GHz, and it can be seen that the first frequency selective surface and the second frequency selective surface which are complementary to each other achieve good signal transmittance function.

[0094] The first metal coating surface 200 and the second metal coating surface 400 of the present application have the first frequency selective surface and the second frequency selective surface which are complementary to each other, respectively, and in order to analyze the heat insulation capacity of the low-emissivity automotive laminated glass implemented by the present application, the first metal coating surface 200 and the second metal coating surface 400 can be equivalent to a single thermal barrier coating, and the area percentage of the etched metal thermal barrier coating to the total thermal barrier coating area is about 0.5% calculated by formula (1-1), which is extremely low for the etching amount of the thermal barrier coating.

[0095] Therefore, the thermal insulation performance of the thermal barrier coating is almost not affected. This effectively solves the problem of converting the thermal barrier coating into a frequency selective surface, achieving communication signal transmittance but losing the heat insulation capacity of the thermal barrier coating.

[0096] Embodiment 2

[0097] In an embodiment of the present application, please refer to Figure 6 and Figure 7 , the first structure unit is a first square patch 202 unit, the first square patch 202 unit has two two adjacent upper left, lower left, upper right and lower right four regions; the first square patch 202 unit includes two first square patches 202, and the two first square patches 202 are located in the lower left region and the upper right region, respectively; the second structure unit is a second square patch 402 unit, the second square patch 402 unit has two two adjacent upper left, lower left, upper right and lower right four regions; the second square patch 402 unit includes two second square patches 402, and the two second square patches 402 are located in the upper left region and the lower right region, respectively.

[0098] In the embodiment, the two first square patches 202 of the first square patch 202 unit and the two second square patches 402 of the second square patch 402 unit are complementarily arranged in the horizontal direction and the vertical direction to achieve a wider frequency response range and better signal transmittance effect.

[0099] Specifically, the two first square patches 202 of the first square patch 202 unit and the two second square patches 402 of the second square patch 402 unit are mirror-symmetric in the horizontal direction, and also mirror-symmetric in the vertical direction. This complementary arrangement makes the entire frequency selective surface achieve good signal transmission characteristics in the horizontal direction and the vertical direction, thereby further widening the frequency response range.

[0100] For the first square patch 202 unit in Figure 6 , it is divided into four small areas (i.e., upper left, lower left, upper right, and lower right) by a straight line parallel to the horizontal edge passing through the vertical midpoint and a straight line parallel to the vertical edge passing through the horizontal midpoint. The two straight lines are perpendicular to each other, and the intersection point is the geometric center of the first square patch 202 unit,

[0101] In an embodiment of the present application, the length a1 of the first square patch 202 ranges from 100 um to 1.5 mm; and the length a2 of the second square patch 402 ranges from 100 um to 1.5 mm.

[0102] In the embodiment, the lengths of the first square patch 202 and the second square patch 402 are designed to enable them to work effectively in different frequency bands. The length range of a1 and a2 enables the two square patches to provide stable signal transmission effects in a wide frequency range. In addition, this length design also takes into account the feasibility and cost-effectiveness of the manufacturing process, ensuring the practicality and market competitiveness of the product. In specific implementation, appropriate length values can be selected within the given range according to actual application requirements and manufacturing process conditions to achieve the best signal transmission effect.

[0103] In an embodiment of the present application, please refer to Figure 6 and Figure 7 , the first square patch 202 has a first etching area 221 at each of its four corners; the shape of the first etching area 221 is a quarter circle with the corner of the first square patch 202 as the center and r1 as the radius; the second square patch 402 has a second etching area 421 at each of its four corners; the shape of the second etching area 421 is a quarter circle with the corner of the second square patch 402 as the center and r2 as the radius.

[0104] In the embodiment, the first etching area 221 and the second etching area 421 further optimize the signal transmission characteristics of the frequency selective surface. Through etching, the accumulation of electromagnetic energy at the corners of the patches is reduced, signal reflection is reduced, and signal transmission effect is improved. At the same time, the quarter-circle etching area design is not only beautiful, but also can effectively disperse electromagnetic waves, reduce interference, and ensure stable signal transmission in different frequency bands. In specific implementation, the values of r1 and r2 can be determined according to actual application requirements and manufacturing process conditions to achieve the best signal transmission effect.

[0105] In one embodiment of the present application, when a1=a2 and r1=r2, the first metal coating surface 200 and the second metal coating surface 400 are complementary, equivalent to a single-layer thermal barrier coating; the area percentage of the first etching area 221 and the second etching area 421 in the total single-layer thermal barrier coating area satisfies the following relationship:

[0106] (1-2)

[0107] In this embodiment, by setting the conditions a1 equal to a2 and r1 equal to r2, the complementarity of the first metal coating surface 200 and the second metal coating surface 400 is achieved, and this design makes them equivalent to a single and more efficient single-layer thermal barrier coating. This innovation not only simplifies the structure, but also further improves the thermal insulation performance. In addition, the area percentage of the first etching area 221 and the second etching area 421 is determined by precise calculation, ensuring that the etching process optimizes the signal transmission characteristics while not excessively weakening the thermal insulation effect. This percentage relationship takes into account the shape, size of the etching area, and the overall layout of the thermal barrier coating, and is the key to achieving a balance between multi-band communication signal transmission and low radiation thermal insulation functions. In specific applications, this design can be flexibly adjusted according to actual needs to meet the specific requirements of different vehicle models and different regions for communication signals and thermal insulation performance.

[0108] In this embodiment, the first metal coating surface 200 can be deposited on one side of the first glass layer 100 by magnetron sputtering technology, and the second metal coating surface 400 can be deposited on one side of the second glass layer 500 by magnetron sputtering technology. The first glass layer 100 and the first metal coating surface 200, and the second glass layer 500 and the second metal coating surface 400 are laminated into a whole low-emissivity automotive laminated glass through the PVB layer 300. And through laser etching or mask technology, the first metal coating surface 200 is converted into an array composed of first square patch 202 units. The second metal coating surface 400 is converted into an array composed of second square patch 402 units, as shown in Figure 8 .

[0109] Specifically, the stacking order, thickness, and electromagnetic characteristic parameters of each component structure of the low-emissivity automotive laminated glass can refer to Table 1 of Embodiment 1.

[0110] In this embodiment, a1=0.5mm and r1=20 microns. To further analyze the multi-band signal transmission effect of the low-emissivity automotive laminated glass with complementary first and second frequency selective surfaces, the S parameter simulation results of the low-emissivity automotive laminated glass implemented in this application are compared with those of bare glass without thermal barrier coating and automotive laminated glass with single-layer thermal barrier coating without etching FSS, as shown in Figure 9as shown.

[0111] wherein the structure of the bare glass without thermal barrier coating is: first glass layer / PVB layer / second glass layer; the structure of the automotive laminated glass with single layer of unetched FSS thermal barrier coating is: first glass layer / PVB layer / thermal barrier coating / second glass layer.

[0112] From the simulation results of Figure 9 It can be seen from the simulation results that the low-emissivity automotive laminated glass implemented by the present application realizes almost the same insertion loss as the automotive laminated glass without thermal barrier coating, and the insertion loss is improved by about -30 to -45 dB compared with the automotive laminated glass with single layer of thermal barrier coating. It can be seen that the low-emissivity automotive laminated glass implemented by the present application realizes good multi-band signal antireflection effect.

[0113] Table 4 summarizes the signal transmission results of the designed square double-layer complementary structure at multiple frequency bands such as operator, satellite navigation, and millimeter wave at normal incidence.

[0114] Table 4

[0115]

[0116] The first metal coating surface 200 and the second metal coating surface 400 of the present application respectively have complementary first and second frequency selective surfaces. In order to realize the thermal insulation capability of the low-emissivity automotive laminated glass implemented by the present application, the first metal coating surface 200 and the second metal coating surface 400 can be equivalent to a single layer of thermal barrier coating. According to formula (1-2), the area of the etched metal thermal barrier coating accounts for about 0.5% of the total thermal barrier coating area, which is extremely low for the etching amount of the thermal barrier coating.

[0117] Therefore, there is almost no impact on the thermal insulation performance of the thermal barrier coating. This effectively solves the problem of converting the thermal barrier coating into a frequency selective surface, realizing communication signal antireflection but losing the thermal insulation capability of the thermal barrier coating.

[0118] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. Any modifications, equivalent replacements and improvements made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A dual-layer complementary frequency selective surface with multi-band communication signal anti-reflection function, characterized in that, This includes a first metal coating surface and a second metal coating surface arranged sequentially; Wherein, the first metal coating surface has a first frequency selective surface; the second metal coating surface has a second frequency selective surface; the pattern of the first frequency selective surface and the pattern of the second frequency selective surface are complementary patterns; The first frequency selective surface includes a plurality of first structural units arranged in an array; the second frequency selective surface includes a plurality of second structural units arranged in an array. The first structural unit is a first square patch unit, which has four adjacent regions: upper left, lower left, upper right, and lower right. The first square patch unit includes two first square patches, which are located in the lower left region and the upper right region, respectively. The second structural unit is a second square patch unit, which has four adjacent regions: upper left, lower left, upper right, and lower right. The second square patch unit includes two second square patches, which are located in the upper left region and the lower right region, respectively. Alternatively, the first structural unit is a hexagonal patch unit, wherein the side length d1 of the hexagonal patch unit ranges from 0.1 mm to 3 mm; the gap w1 between adjacent hexagonal patch units ranges from 1 μm to 1 mm; the second structural unit is a hexagonal strip unit, wherein the side length d2 of the hexagonal strip unit ranges from 0.1 mm to 3 mm; the line width w2 of the hexagonal strip unit ranges from 1 μm to 1 mm; and in the hexagonal strip unit, a partition is provided at the midpoint of each side of the hexagon, wherein the width w3 of the partition ranges from 1 μm to 1 mm.

2. The dual-layer complementary frequency selective surface with multi-band communication signal anti-reflection function as described in claim 1, characterized in that, The first frequency selection surface is either aperture type or patch type; the second frequency selection surface is either aperture type or patch type.

3. The dual-layer complementary frequency selective surface with multi-band communication signal anti-reflection function as described in claim 1, characterized in that, When d1=d2 and w1=w2, the surfaces of the first and second metal coatings are complementary, equivalent to a single-layer metal coating; the partition is formed by etching, and the percentage of the area of ​​the etched-away single-layer metal coating relative to the total area of ​​the single-layer metal coating satisfies the following relationship: 。 4. The dual-layer complementary frequency selective surface with multi-band communication signal anti-reflection function as described in claim 1, characterized in that, The side length a1 of the first square patch ranges from 100um to 1.5mm; the side length a2 of the second square patch ranges from 100um to 1.5mm.

5. The dual-layer complementary frequency selective surface with multi-band communication signal anti-reflection function as described in claim 4, characterized in that, The first square patch has a first etched area at each of its four vertices; the shape of the first etched area is a quarter circle with the vertices of the first square patch as the center and r1 as the radius. The second square patch has a second etched area at each of its four vertices; the shape of the second etched area is a quarter circle with the vertices of the second square patch as the center and r2 as the radius.

6. The dual-layer complementary frequency selective surface with multi-band communication signal anti-reflection function as described in claim 5, characterized in that, When a1=a2 and r1=r2, the surfaces of the first and second metal coatings are complementary, equivalent to a single-layer metal coating; the percentage of the area of ​​the first and second etched regions to the total area of ​​the single-layer metal coating satisfies the following relationship: 。

Images