WO2025168573A1

WO2025168573A1 - Glazing unit and associated decoating method

Info

Publication number: WO2025168573A1
Application number: PCT/EP2025/052837
Authority: WO
Inventors: Mohsen YOUSEFBEIKI; Xavier Dardenne
Original assignee: AGC Glass Europe SA
Current assignee: AGC Glass Europe SA
Priority date: 2024-02-09
Filing date: 2025-02-04
Publication date: 2025-08-14
Anticipated expiration: 2026-08-09

Abstract

The present invention relates to a coated structure The coated structure comprises a substrate, a coating system which is high in reflectance for radio frequency waves; the coating system been disposed over at least a portion of the substrate, and preferably the coating system been disposed over a majority the substrate, a first area defined in the coating system and a second area defined in the coating system comprising an array of isolated patches; each of the isolated patches is isolated from each other by a portion of the first area. Each of the isolated patches comprises non-conductive or substantially non-conductive line segments marked in the coating. The first area has no non-conductive or substantially non-conductive line segments connecting at least two of the isolated patches together. The present invention discloses the associated methods, associated apparatus and uses.

Description

Glazing unit and associated decoating method

Description

Technical Field

[0001] The present invention relates to the field of coated windows, particularly those used in applications where electromagnetic (EM) transparency is desired. More specifically, the invention pertains to a novel approach for achieving enhanced EM signal transmission through a coated window by incorporating decoated regions.

[0002] Thus, the invention concerns multiple domains where a window is used such as mounted on a stationary object, for instance a building, or mounted on a mobile object, for instance a vehicle, a train.

Background Art

[0003] In recent years, there has been a widespread effort to minimize energy consumption in modern buildings and vehicles, such as adopting a more conservative approach to warm in winter or to cool in summer.

[0004] This initiative aims to combat global warming by reducing the influx of heat into/from vehicles and buildings. In order to reduce the accumulation of heat in the interior of a building or vehicle, the glazing unit may be coated with a coating system, for example a solar control coating system, that absorbs or reflects solar energy. Inclusion of solar control films, particularly on glazing for use in warm, sunny climates, is desirable because they reduce the need for air conditioning or other temperature regulation methods.

[0005] This affords savings in terms of energy consumption and environmental impact. On the other hand, a coating system such as a low-emissivity coating can be provided on at least one of the surfaces of the glazing to ensure the thermal comfort inside the building or vehicle.

[0006] The above-mentioned methods to add infra-red ray reflection functions to windows involve the application of a thin film containing a metal with infra-red ray reflection properties, such as silver onto glass substrate. Consequently, such coating systems are typically highly reflective for Radio Frequency (RF) waves. This effect impedes efficient radio-frequency wireless communication to be established between the wireless devices indoors and outdoors. [0007] Nonetheless, wireless devices have become an important part of modern life, especially with the huge penetration of cellular smartphones, tablets, loT (Internet of Things) devices, that are requiring a deep penetration in buildings or automotive of electromagnetic field for indoor coverage, even at high spectrum frequency up to 110 GHz. The 5G NR (New Radio) standard includes lower frequencies, below 6 GHz, and mm-Wave. At mm-Wave, the signal level rapidly decreases due to high path loss.

[0008] Many residential/commercial buildings therefore need outdoor, or outdoor-indoor repeaters and indoor CPEs (Customer-Premises Equipment).

[0009] On top of that, an outdoor unit is typically undesirable for security reasons but also to provide easily power or to avoid environmental conditions that can damage the outdoor unit. In case of an indoor equipment, such as a CPE and/or a repeater, is placed inside the building, the signal is attenuated by at least 30 dB through glazing unit with a typical coated window. This impedes a stable connection to the outdoor base station.

[0010] Therefore, maintaining high transparency of the glazing to radio frequency waves of a specified frequency range has become essential.

[0011] To increase the EM signal transmission through a coated window, a decoating is necessary. A decoating is a process of removing or reducing the coating material from a portion of the window, thereby creating a decoated region that allows more EM signal to pass through. A decoating can be performed by various methods, such as laser ablation, chemical etching, mechanical scratching, etc.

[0012] A chemical etching process can require multiple steps of applying and removing the etching solution, rinsing and drying the window, etc. A mechanical scratching process can cause damage or defects to the substrate or the coating material, such as cracks, scratches, or chips. The laser ablation is a more precise method.

[0013] A generic decoating approach to enhance the transmission of radio frequency waves through a coated system is to remove the coating fully from a large surface.

[0014] A full decoating reduces the thermal performance of the window, as the coating material that provides thermal insulation is removed or reduced. A full decoating can also increase the risk of corrosion or degradation of the substrate, as the coating material that protects the substrate from environmental factors is removed or reduced. To retain the infrared ray reflection function, there is generally a constraint on the maximum amount of the infrared ray reflection film removed by decoating process. In practice, it is advised that the amount of the removed infrared ray reflection film does not exceed 6% of the total coated surface.

[0015] Another generic decoating approach is to eliminate the infrared ray reflection film by forming a periodic pattern well known as frequency selective surface (FSS) structures. The decoating pattern comprises a plurality of parallel lines or curves , with segments devoid of the infrared ray reflection film that for a grid-like structure on the window.

[0016] Such FSS structures exhibit a low-pass filtering characteristic in the frequency domain, enabling signals with frequencies below a certain cutoff frequency to pass through largely unaltered, while gradually attenuating higher frequencies with a gentle roll-off.

[0017] To treat such grid-like structure, the laser has to move along the surface to decoat each line separately as described in W02015050762A1. This takes a long time to partially decoat a window.

[0018] Another method is to decoat sub-grids to create a larger grid pattern. As the surface to treat is large, several sub-grid patterns has to be decoated and connected together as described in US2015202719A1. These connections need a very precise, heavy and cost apparatus to ensure that the decoated lines are aligned and connected together from a sub-grid pattern to the adjacent sub-grid pattern.

[0019] In some applications, which for instance require the indoor coverage of only a part of cellular frequency range, the laser etching of the infrared ray reflection film as a band-pass filter is preferable. This is typically achieved by forming a periodic pattern consisting of isolated open or loop slots.

[0020] However, the infrared ray reflecting film generally does not act as a prefect electric conductor mainly because of its very small thickness compared to the wavelength of radio frequency waves, but as a very lossy conductor. Therefore, the decoating width of the lines composing such band-pass patterns often needs to be sufficiently wide to compensate those losses and to improve the transmission of radio signals into an acceptable level. The need for wide decoated lines implies that a higher amount of the infrared ray reflecting film must be removed, which might not be acceptable from the thermal insulation perspective. Moreover, a treatment with wide decocted lines does not look aesthetic and is not desirable by residents/occupants.

[0021] The document US2015343884 discloses a panel, having at least: at least one first panel having an outer face and an inner face, at least one transparent, electrically-conductive coating, which is arranged on the outer face and/or on the inner face of the first panel, and at least one region having at least one outer de-coated structure and one inner de-coated structure, the transparent, electrically-conductive coating being located between the outer de-coated structure and the inner de-coated structure and inside the inner de-coated structure. However, such panel is not efficient in a large frequency range but only in a very narrow frequency range. On top of that, such decoated structures are not aesthetic.

[0022] The document US2006267856 discloses an electrically conductive coating of an automotive heatable windshield has a communication window having an enhanced frequency selective surface having arranged passing areas (uncoated areas) and blocking areas (coated areas) to pass and block, respectively, predetermined wavelengths of the electromagnetic spectrum. Said frequency selective surface (FSS) includes a plurality of columns spaced from one another by a continuous elongated blocking area. Each of the columns includes passing areas with each of the passing areas have a perimeter with a blocking area in the perimeter spaced from the perimeter. The perimeters of the passing areas contact one another with the blocking area of adjacent passing areas spaced from one another. The elongated blocking area between the break lines and columns extend to the perimeter of the communication window. In this manner current passing through the coating, passes through the communication window to eliminate hot and cold spots around and within the perimeter of the communication window.

[0023] The document US2015229030 discloses an electrically conductive coating of an automotive heatable windshield having a FSS area that facilitates the transmission of radio frequency signals. The FSS area may be a high-pass filter such that RF signals at any polarization can pass through the glazing over a wide frequency band. The FSS area is defined by a pattern in the conductive coating such that, when the conductive coating is used to heat the windshield, electrical current flows through the FSS area to mitigate hot and cold spots.

[0024] These documents disclose decoating patterns. However, each of them needs elongated columns from the top to the bottom to avoid hot spots. Columns cannot be split without creating cold and hot spot while reducing the EM transparency.

[0025] The document CN113682009 discloses a film laminating plate assembly and a vehicle, the film laminating plate assembly comprises a transparent plate and a film layer, the film layer is arranged at one side of the transparent plate, the film layer is provided with a film removing area, a plurality of annular film removing units arranged in an array are arranged in the film removing area, the part, corresponding to the film removing units, of the film layer is removed, and the ratio of the area of film removing units to the film removing area is less than or equal to 10%.

[0026] The document WO2023094355 discloses a system comprising a dielectric substrate and a coating system disposed on the said dielectric substrate. The coating system comprises a Fresnel zone plate lens composed of n coaxial elliptical zones CEZn, n being a positive integer and numbered from 1 to N (n = 1, 2, 3, •••, N wherein N is a positive integer greater than or equals to 2 (N >2)) defining odd and even coaxial elliptical zones. The odd coaxial elliptical zones are partially decoated with a specific odd decoating pattern and / or the even coaxial elliptical zones are partially decoated with a specific even decoating pattern. This disclosure is to focus a EM signal to a specific point on the other side of the dielectric substrate.

[0027] An object of one embodiment of the present invention is to provide a coated structure, especially an insulated glazing unit, capable of maintaining both the thermal and energetical insulation and the indoor coverage of only a part of frequency range by optimizing the trade-off between the RF performance and the decoated area and/or geometric parameters such as length, width of decoated lines.

Summary of invention

[0028] The present invention relates, in a first aspect, to a coated structure. The coated structure comprises a substrate, a coating system which is high in reflectance for radio frequency waves ; the coating system been disposed over at least a portion of the substrate, and preferably the coating system been disposed over a majority the substrate, a first area defined in the coating system and a second area defined in the coating system comprising an array of isolated patches; each of the isolated patches is isolated from each other by a portion of the first area. The array of isolated patch is a two-dimensional array of isolated patch.

[0029] The solution as defined in the first aspect of the present invention is based on that each of the isolated patches comprises non-conductive or substantially non-conductive line segments marked in the coating. The non- conductive or substantially non-conductive line segments marked in the coating of each of the isolated patches are interconnected to form a grid or a mesh inside each patch.

[0030] The solution as defined in the first aspect of the present invention is also based on that the first area has no non-conductive or substantially non- conductive line segments connecting at least a line segment of one of the isolated patches to a line of another isolated patch.

[0031] The present invention relates, in a second aspect, to a manufacturing method to produce a coated structure according to the first aspect of the present invention. The manufacturing method comprises following steps:

Al. Providing a substrate

A2. Deposing a coating system which is high in reflectance for RF radiation disposed over at least a portion of the substrate,

A3. Creating in the coating system the array of isolated patches.

[0032] The present invention relates, in a third aspect, to a second manufacturing method to produce a coated structure according to the first aspect of the present invention. The manufacturing method comprises the following steps:

Bl. Providing a substrate

B2. Masking the substrate with a mask

B3. Deposing a coating system which is high in reflectance for RF radiation disposed over at least a portion of the substrate and over at least a portion of the mask,

B4. Removing the mask to create in the coating system the array of isolated patches. [0033] The present invention relates, in a fourth aspect, to a use of a first pattern comprising an array of periodic isolated patches in a coated structure according to claim 1 to 11 to tune the transmission of radio frequency waves through the coated structure over a specific frequency range.

[0034] It is noted that the invention relates to all possible combinations of features recited in the claims or in the described embodiments.

[0035] The following description relates to building applications, but it’s understood that the invention may be applicable to other fields like automotive or transportation applications such as train.

Brief description of the drawings

[0036] This and other aspects of the present invention will now be described in more detail, with reference to the appended drawings showing various exemplifying embodiments of the invention which are provided by way of illustration and not of limitation. The drawings are a schematic representation and not true to scale. The drawings do not restrict the invention in any way. More advantages will be explained with examples.

[0037] FIG. 1 is a schematic view of a coated structure according to the first aspect of the invention.

[0038] FIG. 2 is a schematic view of a two-dimensional array of isolated patches according to some embodiments of the present invention.

[0039] FIG. 3 is a schematic view of an isolated patch according to some embodiments of the present invention.

[0040] FIG. 4 is a graph of the transmission for a grid 2x2 mm at a frequency of 2.6 GHz.

[0041] FIG. 5 is a graph of the transmission for a grid 2x2 mm at a frequency of

3.5 GHz.

[0042] FIG. 6 is a graph of the transmission for a grid 4x4 mm at a frequency of

2.6 GHz.

[0043] FIG. 7 is a graph of the transmission for a grid 4x4 mm at a frequency of 3.5 GHz.

[0044] FIG. 8 is a schematic view of the method according to the second aspect of the present invention. [0045] FIG. 9 is a schematic view of the method according to the third aspect of the present invention.

Detailed description

[0046] In this document to a specific embodiment and include various changes, equivalents, and / or replacements of a corresponding embodiment. The same reference numbers are used throughout the drawings to refer to the same or like parts.

[0047] As used herein, spatial or directional terms, such as "inner", "outer", "above", "below", "top", "bottom", and the like, relate to the invention as it is shown in the drawing figures. However, it is to be understood that the invention can assume various alternative orientations and, accordingly, such terms are not to be considered as limiting. Further, all numbers expressing dimensions, physical characteristics, processing parameters, quantities of ingredients, reaction conditions, and the like, used in the specification and claims are to be understood as being modified in all instances by the term "about". Accordingly, unless indicated to the contrary, the numerical values set forth in the following specification and claims are approximations that can vary depending upon the desired properties sought to be obtained by the present invention. In the following description, unless otherwise specified, expression “substantially” mean to within 10%, preferably to within 5%.

[0048] Moreover, all ranges disclosed herein are to be understood to be inclusive of the beginning and ending range values and to encompass any and all subranges subsumed therein. For example, a stated range of "1 to 10" should be considered to include any and all subranges between (and inclusive of) the minimum value of 1 and the maximum value of 10; that is, all subranges beginning with a minimum value of 1 or more, e.g. 1 to 6.1, and ending with a maximum value of 10 or less, e.g., 5.5 to 10. Further, as used herein, the terms "deposited over" or "provided over" mean deposited or provided on but not necessarily in surface contact with. For example, a coating "deposited over" a substrate does not preclude the presence of one or more other coating films of the same or different composition located between the deposited coating and the substrate. [0049] Where the term “comprising” is used in the present description and claims, it does not exclude other elements or steps. Where an indefinite or definite article is used when referring to a singular noun e.g. "a" or "an", "the", this includes a plural of that noun unless something else is specifically stated. In this document, "configured to (or set to)" may be interchangeably used in hardware and software with, for example, "appropriate to", "having a capability to", "changed to", "made to", "capable of", or "designed to" according to a situation. In any situation, an expression "device configured to do" may mean that the device "can do" together with another device or component.

[0050] Furthermore, the terms first, second and the like in the description and in the claims, are used for distinguishing between similar elements and not necessarily for describing a sequence, either temporally, spatially, in ranking or in any other manner. It is to be understood that the terms so used are interchangeable under appropriate circumstances and that the embodiments of the invention described herein are capable of operation in other sequences than described or illustrated herein. When it is described that a constituent element (e.g., a first constituent element) is "(functionally or communicatively) coupled to" or is "connected to" another constituent element (e.g., a second constituent element), it should be understood that the constituent element may be directly connected to the another constituent element or may be connected to the another constituent element through another constituent element (e.g., a third constituent element).

[0051] It is an object of the present invention to alleviate the above described problems by proposing an efficient and discrete frequency selective decoated grid portion on the coating system.

[0052] Especially, as illustrated in FIG. 1, the object of the first aspect of the present invention is a coated structure 100 especially a glazing unit.

[0053] A glazing unit, according to the invention, can be used as a window, especially to close an opening of the stationary object, such as a building, or to close an opening of the mobile object, such a train, a boat, a car,...

[0054] In FIG. 1, the glazing unit has a height measured along the Z-axis, a width measured along the X-axis and a thickness measured along the Y-axis. The shape of the glazing panel in a plane view (X-Z plane) is not limited to a rectangle, and may be a circle or the like. In the present embodiment, the rectangle includes not only a rectangle or a square but also a shape obtained by chamfering corners of a rectangle or a square. The dimensions and/or the shape of the glazing unit depends on the desired application.

[0055] According to the invention, the coated structure comprises a substrate. The substrate is preferably low in reflectance for RF waves.

[0056] In some embodiments, the substrate is a plastic-based substrate such as polycarbonate, Clear acrylic, or polyethylene terephthalate glycol (PETG) substrate or any suitable plastic-based substrate. <Glass sheet>

[0057] In some preferred embodiments of the present invention, the substrate 1 comprises a glazing panel comprising a glass sheet 1 which is preferably low in reflectance for RF waves.

[0058] Low in reflectance for RF waves means that RF waves are mostly transmitted through the material where high in reflectance for RF waves means that RF waves are mostly reflected on the surface of the material and/or absorbed by the material and the transmittance attenuation is at level of 20 decibels (dB) or more. Low in reflectance means a transmittance attenuation at level of 10 decibels (dB) or less.

[0059] The shape of the glazing panel in a plane view (X-Z plane) is not limited to a rectangle, and may be a circle or the like. In the present embodiment, the rectangle includes not only a rectangle or a square but also a shape obtained by chamfering corners of a rectangle or a square.

[0060] In some embodiments, the glass sheet is at least transparent for visible waves in order to see-through and to let visible light passing through, meaning that the light transmission is greater than or equal to 1 %.

[0061] In some embodiments, the glazing panel comprises at least two glass sheets separated by a spacer allowing to create a space filled by a gas like Argon to improve the thermal isolation of the glazing unit, creating an insulating glazing unit.

[0062] In some embodiments, the glazing panel comprises at least two glass sheets separated by spacers allowing to create a vacuum space to improve the thermal isolation of the glazing unit, creating a vacuum insulating glazing (VIG). [0063] In some embodiments, the glazing panel can be a laminated glazing panel to reduce the noise and/or to ensure the penetration safety. The laminated glazing comprises glazing panels maintained by one or more interlayers positioned between glazing panels. The interlayers employed are typically polyvinyl butyral (PVB) or ethylene-vinyl acetate (EVA) for which the stiffness can be tuned. These interlayers keep the glazing panels bonded together even when broken in such a way that they prevent the glass from breaking up into large sharp pieces.

[0064] As the material of the glazing panel, for example, soda-lime silica glass, borosilicate glass, or aluminosilicate glass can be mentioned or other materials such as thermoplastic polymers, polycarbonates are known, especially for automotive applications, and references to glass throughout this application should not be regarded as limiting.

[0065] The glazing panel can be manufactured by a known manufacturing method such as a float method, a fusion method, a redraw method, a press molding method, or a pulling method. As a manufacturing method of the glazing panel, from the viewpoint of productivity and cost, it is preferable to use the float method.

[0066] The glass sheet can be flat or curved according to requirements by known methods such as hot or cold bending.

[0067] The glass sheet can be processed, i.e. annealed, tempered, ••• to respect with the specifications of security and anti-thief requirements.

[0068] The glass sheet can be a clear glass or a colored glass, tinted with a specific composition of the glass or by applying an additional coating or a plastic layer for example.

[0069] In case of several glass sheets, in some embodiments, each glass sheet can be independently processed and/or colored, ••• in order to improve the aesthetic, thermal insulation performances, safety, •••

[0070] The thickness of the glazing panel is set according to requirements of applications.

[0071] The glazing panel can be formed in a rectangular shape in a plan view by using a known cutting method. As a method of cutting the glazing panel, for example, a method in which laser light is irradiated on the surface of the glazing panel to cut the irradiated region of the laser light on the surface of the glazing panel to cut the glazing panel, or a method in which a cutter wheel is mechanically cutting can be used. The glazing panel can have any shape in order to fit with the application, for example a windshield, a sidelite, a sunroof of an automotive, a lateral glazing of a train, a window of a building, •••

[0072] In addition, the glazing unit can be assembled within a frame or be mounted in a double skin faqade, in a carbody or any other means able to maintain a glazing unit. Some plastics elements can be fixed on the glazing panel to ensure the tightness to gas and/or liquid, to ensure the fixation of the glazing panel or to add external element to the glazing panel.

[0073] According to the invention, the coated structure 100 comprises a coating system 2 which is high in reflectance for RF waves. Said coating system 2 is disposed on the said substrate 1.

[0074] In the sense of the present invention, the term “disposed on” means that the coated system is placed over at least a portion of the substrate on a major surface of the substrate. Preferably, the coating system is disposed over a majority of the substrate.

[0075] The coating system is high in reflectance and low in transmittance for RF waves. Low in transmittance means a transmission with an attenuation up to 20 decibels (dB) or more. It is understood that the substrate can generally be low in reflectance, meaning an attenuation at level of 10 decibels (dB) or less.

[0076] According to the invention, the coating system 2 can be a functional coating in order to heat the surface of the glass sheet, to reduce the accumulation of heat in the interior of a building or vehicle or to keep the heat inside during cold periods for example. Although coating system are thin and mainly transparent to eyes in order to see-through and to let visible light passing through.

[0077] The coating system 2 can be made of layers of different materials and at least one of this layer is electrically conductive. The coating system is electrically conductive over the majority of one major surface of the glass sheet, in the X-Z plane.

[0078] The coating system 2 of the present invention has an emissivity of not more than 0.4, preferably less than 0.2, in particular less than 0.1, less than 0.05 or even less than 0.04. The coating system of the present invention may comprise a metal based low emissive coating system; these coatings typically are a system of thin layers comprising one or more, for example two, three or four, functional layers based on an infrared radiation reflecting material and at least two dielectric coatings, wherein each functional layer is surrounded by dielectric coatings. The coating system of the present invention may in particular have an emissivity of at least 0.010. The functional layers are generally layers of silver with a thickness of some nanometres, mostly about 5 to 20nm. Concerning the dielectric layers, they are transparent and traditionally each dielectric layer is made from one or more layers of metal oxides and/or nitrides. These different layers are deposited, for example, by means of vacuum deposition techniques such as magnetic field-assisted cathodic sputtering, more commonly referred to as "magnetron sputtering", or Chemical deposition such as CVD or PECVD or any other known deposition method. In addition to the dielectric layers, each functional layer may be protected by barrier layers or improved by deposition on a wetting layer.

[0079] In some embodiments, the coating system 2 is applied to the dielectric substrate 2, especially a glazing panel, to transform it to a low-E glazing unit. This metal-based coating system can be such as low-E or heatable coating systems.

[0080] In some embodiments, the coating system 2 can be a heatable coating applied on the dielectric substate, especially a glazing panel, to add a defrosting and/or a demisting function for example.

[0081] As the coating system, for example, a conductive film can be used. As the conductive film, for example, a laminated film obtained by sequentially laminating a transparent dielectric, a metal film, and a transparent dielectric, ITO, fluorine-added tin oxide (FTO), or the like can be used. As the metal film, for example, a film containing as a main component at least one selected from the group consisting of Ag, Au, Cu, and Al can be used.

[0082] Preferably, the coating system is placed on the majority of one surface of the glazing unit and more preferably on the whole usable surface of the glazing panel, in the X-Z plane.

[0083] In some embodiments, a masking element, such as an enamel layer, can be add on a part of the periphery of the glazing unit to hide the transition between a coated area and a non-coated area. [0084] In some embodiments, the glazing unit can comprise several coating systems applied on same or different surface(s) of a glass sheet.

[0085] In some embodiments where the glazing panel comprises several glass sheets, different or same coating systems can be placed on different surfaces of the glass sheets.

[0086] According to the invention, the coated substrate comprises a first area 21 defined in the coating system. The coated substrate also comprises a second area 22 defined in the coating system and comprising an array of isolated patches 221, 222, 223, 224, 225, 226, 227, 228, 229. The array of isolated patches is a two-dimensional array of isolated patches to tune the transmission of radio frequency waves through the coated structure over a specific frequency range in all polarisations.

[0087] According to the invention, each of the isolated patches comprises non- conductive or substantially non-conductive line segments marked in the coating. [0088] As illustrated in FIG. 1 and FIG. 2, each of the isolated patches is isolated from each other by a portion of the first area.

[0089] According to the invention, the first area has no non-conductive or substantially non-conductive line segment connecting at least a line segment of one of the isolated patches to a line of another isolated patch.

[0090] As illustrated in FIG. 2 and FIG. 3, the non-conductive or substantially non-conductive line segments marked in the coating of each of the isolated patches are interconnected to form a grid or a mesh inside each patch. The non- conductive or substantially non-conductive line segments marked in the coating creates cells of the coating system. Each grid or mesh comprises at least 2x1 cells, meaning two rows and one column, or 1x2 cells, meaning one row and two columns.

[0091] In preferred embodiments, each grid or mesh has at least three rows and three columns.

[0092] In some preferred embodiments, each grid or mesh has at max twenty- five rows, preferably each grid or mesh has at max twenty rows, even more preferably, each grid or mesh has at max fifteen rows. In some preferred embodiments, each grid or mesh has at max twenty-five columns, preferably each grid or mesh has at max twenty columns, even more preferably, each grid or mesh has at max fifteen columns. [0093] It is understood that all non-conductive or substantially non-conductive line segments of an isolated patch cannot fully cover said isolated patch meaning that said isolated patch cannot be fully decoated.

[0094] In the sense of the present invention, the term “isolated” means that there is no non-conductive or substantially non-conductive line segment marked in the coating between two patches that means that the first area is continuous and forms a single area. In other terms, no non-conductive or substantially non- conductive line segment can connect at least a line segment of one of the isolated patches to a line of another isolated patch.

[0095] In some embodiments, the first area can comprise at least one non- conductive or substantially non-conductive line segment marked in the coating but such at least one non-conductive or substantially non-conductive line segment cannot connect two isolated patches together

[0096] It is understood that the second area is defined by the union of the surface of each of the isolated patches.

[0097] According to the invention, the array of isolated patches means that the isolated patches are arranged in rows and columns.

[0098] In some preferred embodiments, the isolated patches has same generic outer contour to facilitate the decoating process while improving the interaction between isolated patches.

[0099] In such preferred embodiments, each of the isolated patches has the same proportion meaning that dimensions can differ from one to another isolated patch while keeping the same ratio between dimensions.

[00100] In some preferred embodiments, to increase the EM transparency the array of the isolated patches forms a periodic array. That means that the outer contour of the isolated patches can be different, but the isolated patches of the array are arranged in a periodic manner. In such embodiments, the second area can comprise isolated patches with two or more different outer shapes as long as all isolated patches are arranged in a periodic manner.

[00101] To facilitate the manufacture of the coated structure of the present invention, in some embodiments, the generic outer contour can be a rectangle meaning that non-conductive or substantially non-conductive line segments are enclosed inside said rectangle. In some specific embodiments of such embodiments, the array can comprise isolated patches with different rectangle dimensions.

[00102] In some even preferred embodiment, edges of each of the isolated patches can substantially be parallel to the edge of the adjacent isolated patch as illustrated in FIG. 3.

[00103] In FIG. 3, opposite to FIG. 2, black lines represent the non-conductive or substantially non-conductive line segments marked in the coating; in FIG. 2 white lines represent the non-conductive or substantially non-conductive line segments marked in the coating.

[00104] The line segments can be visible in some incident angle due to the difference of colour between the decoating and the coating system and the dimensions of said lines.

[00105] The position and the general size of the first and second areas can depend on the desired application.

[00106] The second area has decoated regions in the form of non-conductive or substantially non-conductive line segment, in black colour in FIG. 3 and in white colour in FIG. 2, in the form of parallel lines or grid lines arranged in a mesh-like manner, creating zones, in white colour in FIG. 3 and grey colour in FIG. 2, where the coating system is still present. This permits to maximize the untouched, meaning the surface in which the coating system has not been removed, surface of the coating system to keep properties of the coating system.

[00107] According to the invention, the isolated patch area percentage (ipap) is characterized by the formula: area of the patch i^{pap =} (Dl')x (Hl')

[00108] DI’ is the distance between a same point of two adjacent patches in the direction of the length. Hl’ is the distance between a same point of two adjacent patches in the direction of the height (substantially perpendicular to the direction of the height). The area of the patch is the area comprised between the non-conductive or substantially non-conductive line segments of said patch. The formula represents the proportion of the area occupied by the array of the isolated patches in the coating system

[00109] FIG. 3 illustrates some preferred embodiments in which the array comprises isolated patches 221, 222, 224, 225 (only a portion of an array being illustrated in FIG. 2 and FIG. 3). The isolated patches 221, 222, 224, 225 have a generic outer contour in a shape of a rectangle having the same dimensions, a length Lc and a height He. Each of the isolated patches are distant from another by a distance DI in the direction of the length and a distance Hl in the direction of the height. In such embodiments, the isolated patch area percentage (ipap) is characterized by the formula:

Le x He i^{pap =} (Lc + Dl)x (He + Hl)

[00110] The formula Fl represents the proportion of the area occupied by the array of the isolated patches in the coating system.

[00111] According to the invention, non-conductive or substantially non- conductive line segment in the form of parallel lines or grid lines arranged in a mesh-like manner form a low-pass frequency surface (FSS) in each of the isolated patches.

[00112] According to the invention, the first area and the second area form together a band-pass FSS in the coating system.

[00113] Unlike prior arts, which seeks to form a FSS by partially decoating the entire surface, the present invention reduces the partially decoated surface while keeping even increasing the EM transparency of the coating system at a desired frequency range.

[00114] According to the invention, the non-conductive or substantially non- conductive line segments of an isolated patch forms the partially decoated surface of the isolated patch.

[00115] According to the invention, the non-conductive or substantially non- conductive line segments of the isolated patches form a grid or a mesh meaning that some of the line segments are substantially parallel to each other and oriented in a direction while the others of the line segments are substantially parallel to each other and oriented in another direction. Preferably, the grid or the mesh is a rectangular grid or a rectangular mesh, meaning that each of the unit cells of the grid/mesh created by the intersection of the line segments forms a rectangle, the grid/mesh has a rectangular unit cell, and more preferably, the grid or the mesh is a square grid or a square mesh, meaning that each of the unit cells of the grid/mesh created by the intersection of the line segments forms a square. Unit cells have a length of Lg and a height of Hg. [00116] In some embodiments, some of line segments can close the grid/mesh to form a partially closed grid/mesh and preferably, in such embodiments, the grid/mesh is a fully closed grid/mesh as illustrated in FIG. 3.

[00117] In some embodiments, the grid/mesh is a partially opened grid/mesh meaning that at a border the grid/mesh has a rack design and line segments extends from the last interactions with another line segment and preferably, in such embodiments, the grid/mesh is a fully open grid/mesh.

[00118] In some other preferred embodiments, the non-conductive or substantially non-conductive line segments of the isolated patches form parallel lines meaning that line segments of each of the isolated patches are substantially parallel and aligned in a defined direction. Preferably, the defined direction is parallel or perpendicular to the rectangular shape of the outer contour.

[00119] In some preferred embodiments, to facilitate the decoating process while optimizing the EM transparency, the non-conductive or substantially non- conductive line segments of each of the isolated patches of an array of isolated patches form the same decoated pattern.

[00120] To let RF waves passing thought the coating system and through the substrate depends on the line segments parameters, such as distance between line segments, especially for grid/mesh, and shape of the line segments and the way to fit them together, especially for grid/mesh.

[00121] In mesh/grid embodiments, the grid meshes must have a distance between the line segments that is significantly smaller than the wavelength of the desired electromagnetic waves in question. To that end, the metalcontaining coatings are, for example, removed in the form of lines using a suitable laser. Since only small amounts of the metal-containing coating have to be removed, the infrared radiation absorbing effect is largely retained.

[00122] Preferably, decoated segments can have a width between 10 pm and 150 pm, preferably between 20 pm and 60 pm, and more preferably substantially 35 pm.

[00123] In some embodiments where the line segments form a square grid/mesh, the squares as illustrated in FIG. 3, the unit cells, are substantially 2 mm x 2 mm squares. In some other embodiments squares, the unit cells, are substantially 4 x 4 mm squares. Dimensions of the squares depend on the desired EM frequency range to let pass through the glazing unit.

[00124] In some preferred embodiments where the line segments form a square grid/mesh, the length Lc can be substantially equal to the height He to facilitate the process of decoating while optimizing the trade-off between the transmission and the decoating percentage.

[00125] FIG. 4 illustrates a specific example where Lc = He and grid size of 2 mm x 2 mm, the width of the decoated lines is about 40 pm, frequency of interest: 2.6 GHz, the coated structure comprises a laminated glazing (first glass sheet 1.6mm / 0.76 mm PVB / second glass sheet 1.6 mm with a coated system between the first glass sheet and the PVB. Table 1 and Table 2 illustrate points of FIG. 4, corresponding to the required decoated percentage for different values of Lc and the isolated patch area percentage as well as the corresponding transmission of EM waves.

[00126] FIG. 5 illustrates a specific example where Lc = He and grid size of 2 mm x 2 mm, the width of the decoated lines is about 40 pm, frequency of interest:

3.5 GHz ••• The coated structure comprises a laminated glazing (first glass sheet 1.6mm / 0.76 mm PVB / second glass sheet 1.6 mm with a coated system between the first glass sheet and the PVB.

[00127] FIG. 6 illustrates a specific example where Lc = He and grid size of 4 mm x 4 mm, the width of the decoated lines is about 40 pm, frequency of interest:

2.6 GHz ••• The coated structure comprises a laminated glazing (first glass sheet 1.6mm / 0.76 mm PVB / second glass sheet 1.6 mm with a coated system between the first glass sheet and the PVB.

[00128] FIG. 7 illustrates a specific example where Lc = He and grid size of 4 mm x 4 mm, the width of the decoated lines is about 40 pm, frequency of interest: 3.5 GHz ••• The coated structure comprises a laminated glazing (first glass sheet 1.6mm / 0.76 mm PVB / second glass sheet 1.6 mm with a coated system between the first glass sheet and the PVB.

[00129] The present invention permits to improve the transmission beyond the prior art and with less decoating percentage as illustrated in table 1 and table 2 and in FIG. 4 - FIG. 7. .

[00130] Preferably, each of the isolated patches of the array of isolated patches has an isolated patch area percentage (ipap) between 0.4 and 0.9, preferable between 0.6 and 0.8. Surprisingly, the inventors found that the trade-off between the transmission and the decoating percentage is optimum for an isolated patch area percentage between 0.4 and 0.9 as illustrated in FIG. 4- FIG. 7, preferable between 0.6 and 0.8.

[00131] Preferably, each of the isolated patches of the array of isolated patches has an length (Lc) between 0.3 and 0.7 as illustrated in FIG. 4- FIG. 7. Surprisingly, the trade-off between the transmission and the decoating percentage is optimum for a length of the isolated patch between 0.30 and 0.70 of the effective wavelength. The finer the grid size, the optimal length of the isolated patch can be larger. The coarser the grid size, the optimal length of the isolated patch can be smaller.

[00132] In the sense of the present invention, the effective wavelength refers to the wavelength at which the signal behaves as it propagates through a given medium or interacts with objects in its path such as substrate, glass, interlayer, ••• It is different from the free-space wavelength, which is the wavelength of the signal in a vacuum.

[00133] A dual-frequency performance can be achieved by selecting an appropriate length of the isolated patch between the optimal length value of each said frequency.

[00134] FIG. 8 illustrates the second aspect of the present invention. The manufacturing method of the second aspect of the present invention permits to produce a coated structure according to the first aspect of the present invention. The manufacturing method comprises a step 801 of providing a substrate. Then, the manufacturing method comprises a step 802 of deposing a coating system which is high in reflectance for RF waves disposed over at least a portion of the substrate to form a coated substrate. After the deposition step, the manufacturing method comprises a step 803 of creating in the coating system the array of isolated patches. This creation step 803 can be performed in a factory or in situ with a decoating apparatus.

[00135] The decoating apparatus can be fixed on the glazing unit and/or around the glazing unit such as a frame surrounding the glazing unit, a car body, a wall or alike.

[00136] The decoating apparatus can also stand in front of the glazing unit to decoat. [00137] Some exemplary decoating apparatus are described in

W02015050762, WO2022112532, WO2021165064, WO2021165065,

WO2021239603, WO2022079225, WO2022112530, WO2022112529,

WO2022112521.

[00138] It is understood that any other apparatus that can decoat using the method according to the second aspect and/or providing a glazing unit according to the first aspect of the present invention can be used.

[00139] FIG. 9 illustrates the third aspect of the present invention. This second manufacturing method differs from the second aspect of the present invention by the way to create the array of isolated patches.

[00140] The second manufacturing method comprises a step 901 of providing a substrate. Then, the manufacturing method comprises a step 902 of masking the substrate with a mask. The mask has the shape of the array of isolated patches to create. After the masking step 902, the second manufacturing method comprises a step 903 of deposing a coating system which is high in reflectance for RF waves disposed over at least a portion of the substrate and over at least a portion of the mask. Then, the second manufacturing method comprises a step 904 of removing the mask to create in the coating system the array of isolated patches.

[00141] The mask can be removed by heating, by cleaning, by mechanical actions, by acid or any other suitable manner to remove a temporary mask.

[00142] The present invention permits, with these different aspects, thanks to the creation of a first area and a second area comprising an array of periodic isolated patches in a coated structure as described above to tune the frequency range of EM transparency while minimizing the sum of length of non-conductive or substantially non-conductive line segments.

[00143] The present invention, with these different aspects, permits to obtain a coated structure optimizing the decoating time while keeping the same or increased EM transparency compared to the prior art.

Table 1: The transmission as a function of the length of the isolated patch and the isolated patch area percentage.

Table 2: The decoating percentage as a function of the length of the isolated patch and the isolated patch area percentage.

Claims

Claim 1. A coated structure (100); the coated structure comprises:

- a substrate (1),

- a coating system (2) which is high in reflectance for radio frequency waves; the coating system been disposed over at least a portion of the substrate,

- a first area (21) defined in the coating system

- a second area (22) defined in the coating system comprising a two-dimensional array of isolated patches (221, 222, 223, 224, 225, 226, 227, 228, 229); each of the isolated patches is isolated from each other by a portion of the first area characterized in that each of the isolated patches comprises non- conductive or substantially non-conductive line segments marked in the coating in that the non-conductive or substantially non-conductive line segments marked in the coating of each of the isolated patches are interconnected to form a grid or a mesh inside each patch (def = 2x1 - 2006 def?) and in that the first area has no non-conductive or substantially non- conductive line segment connecting at least a line segment of one of the isolated patches to a line of another isolated patch.

Claim 2. Coated structure according to claim 1, wherein each of the isolated patches has the same generic outer contour.

Claim 3. Coated structure according to claim 2, wherein the array of the isolated patches forms a periodic array.

Claim 4. Coated structure according to any preceding claims, wherein the outer contour is a rectangle.

Claim 5. Coated structure according to claim 3, wherein edges of each of the isolated patches are substantially parallel to the edge of the adjacent isolated patch.

Claim 6. Coated structure according to any preceding claims, each grid or mesh has at least three rows and three columns.

Claim 7. Coated structure according to any preceding claims, wherein each of the isolated patches of the array of isolated patches has an isolated patch area percentage (ipap) between 0.4 and 0.9, preferable between 0.6 and 0.8.

Claim 8. Coated structure according to claim 6, wherein the non- conductive or substantially non-conductive mesh has rectangular unit cells.

Claim 9. Coated structure according to any preceding claims, wherein the non-conductive or substantially non-conductive line segments of each of the isolated patches form the same decoated pattern.

Claim 10. Coated structure according to claims 1 - 9, wherein the substrate comprises a glazing panel.

Claim 11. Coated structure according to claims 1 - 9, wherein the substrate is a plastic-based substrate.

Claim 12. Manufacturing method to produce a coated structure according to claims 1 to 11, the manufacturing method comprises following steps:

Al. Providing (801) a substrate

A2. Deposing (802) a coating system which is high in reflectance for RF radiation disposed over at least a portion of the substrate,

A3. Creating (803) the array of isolated patches.

Claim 13. Manufacturing method according to claim 12, wherein the creating step is performed by ablation of the coating system or by melting the coating system.

Claim 14. Manufacturing method according to claim 12 or claim 13, wherein the manufacturing method is performed in situ.

Claim 15. Manufacturing method to produce a coated structure according to claims 1 to 11, the manufacturing method comprises following steps:

Bl. Providing (901) a substrate

B2. Masking (902) the substrate with a mask

B3. Deposing (903) a coating system which is high in reflectance for RF radiation disposed over at least a portion of the substrate and over at least a portion of the mask,

B4. Removing (904) the mask to create in the coating system the array of isolated patches.