Glazing unit and associated decoating method

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. The second area consists of a two-dimensional array of isolated patches of the coating system; each of the isolated patches is isolated from each other by a portion of the first area. The first area comprises non-conductive or substantially non-conductive line segments marked in the coating system; said non-conductive or substantially non-conductive line segments are interconnected to form a grid or a mesh having cells. The second area has no non-conductive or substantially non-conductive line segment connecting a line of the first area. The surface of each of the isolated patch is at least three times larger than the mean of the surface of the cells. The present invention discloses the associated methods, associated apparatus and uses.

Description

Glazing unit and associated decoating methodDescriptionTechnical 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 have 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] In some other applications, which for instance require the indoor radiofrequency coverage excluding a specific portion of the defined frequency range, the laser etching of the infrared ray reflection film as a band-stop filter is preferable. This is typically achieved by forming a periodic pattern of coating consisting of isolated dipoles or loops.

[0021] However, the coating surface of such periodic band-stop patterns often needs to be sufficiently small compared to the surface of the unit cell of the periodic structure in order to balance between the rejection at that specific portion of the defined frequency range and the transmission at the rest of frequencies of interest, compensate those losses and to improve the transmission of radio signals into an acceptable level. This implies that the majority of the infrared ray reflecting film must be removed, which is often not acceptable from the thermal insulation perspective. Moreover, such a treatment does not look aesthetic, and is not desirable by residents / occupants.

[0022] 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 except for only a part of frequency range by optimizing the trade-off between the RF performance and the decoated area.Summary of invention

[0023] 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. The coated structure also comprises a first area defined in the coating system and a second area defined in the coating system.

[0024] The solution as defined in the first aspect of the present invention is based on that the second area consists of a two-dimensional array of isolated patches of the coating system; each of the isolated patches is isolated from each other by a portion of the first area.

[0025] The solution as defined in the first aspect of the present invention is also based on that the first area comprises non-conductive or substantially non- conductive line segments marked in the coating system; said non-conductive or substantially non-conductive line segments are interconnected to form a grid or a mesh having cells.

[0026] The solution as defined in the first aspect of the present invention is also based on that the second area has no non-conductive or substantially non- conductive line segment connected to a line of the first area.

[0027] The solution as defined in the first aspect of the present invention is also based on that the surface of each of the isolated patch is at least three times larger than the mean of the surface of the cells, enhancing the effectiveness of the transparency. Preferably, the isolated patches can be designed to resonate at specific frequencies, thereby improving the frequency selectivity of the coated structure.

[0028] 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 the first area by creating non-conductive or substantially non-conductive line segments surrounding at least partially an array of isolated patches of the coating system.

[0029] 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 the first area having non-conductive or substantially non-conductive line segments surrounding at least partially an array of isolated patches of the coating system.

[0030] The present invention relates, in a fourth aspect, to a use of a first area and a second area according to the first aspect of the present invention to tune the transmission of radio frequency waves through the coated structure over a specific frequency range.

[0031] The present invention relates, in a fifth aspect, to a mobile object, for instance a vehicle, a train, a plane, a boat, or alike, comprising a window; said window being a coated structure according the first aspect of the present invention.

[0032] The present invention relates, in a fifth aspect, to a stationary object, for instance a building or alike, comprising a window; said window being a coated structure according the first aspect of the present invention.

[0033] It is noted that the invention relates to all possible combinations of features recited in the claims or in the described embodiments.

[0034] The following description relates to a mobile object such as a train applications but it’s understood that the invention may be applicable to others fields like automotive or stationary objects.Brief description of the drawings

[0035] 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.

[0036] FIG. 1 is a schematic view of a coated structure according to the first aspect of the invention.

[0037] FIG. 2 - FIG. 6 are schematic views of a two-dimensional array of isolated patches according to some different embodiments of the present invention.

[0038] FIG. 7 is a schematic view of a mobile object according to the fifth aspect of the present invention.

[0039] FIG. 8 is a schematic view of the method according to the second aspect of the present invention.

[0040] FIG. 9 is a schematic view of the method according to the third aspect of the present invention.Detailed description

[0041] In this document to a specific embodiment and include various changes, equivalents, and / or replacements of a corresponding embodiment. The samereference numbers are used throughout the drawings to refer to the same or like parts.

[0042] 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%.

[0043] 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.

[0044] 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 asituation. In any situation, an expression "device configured to do" may mean that the device "can do" together with another device or component.

[0045] 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).

[0046] 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.

[0047] Especially, as illustrated in FIG. 1, the object of the first aspect of the present invention is a coated structure 100 comprising a substrate. The substrate is preferably low in reflectance for RF waves.

[0048] In some preferred embodiments, the substate is a glazing unit. <glazing unit>

[0049] 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,...

[0050] In FIG. 1, the substrate is a glazing unit. Said 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.

[0051] 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>

[0052] In some preferred embodiments of the present invention, the glazing panel comprises a glass sheet which is preferably low in reflectance for RF waves.

[0053] 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.

[0054] In some embodiments, the substrate 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 %.

[0055] 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.

[0056] 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).

[0057] 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.

[0058] 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 forautomotive applications, and references to glass throughout this application should not be regarded as limiting.

[0059] 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.

[0060] The glass sheet can be flat or curved according to requirements by known methods such as hot or cold bending.

[0061] The glass sheet can be processed, i.e. annealed, tempered, ••• to respect with the specifications of security and anti-thief requirements.

[0062] The glass sheet can be a clear glass or a coloured glass, tinted with a specific composition of the glass or by applying an additional coating or a plastic layer for example.

[0063] In case of several glass sheets, in some embodiments, each glass sheet can be independently processed and / or coloured, ••• in order to improve the aesthetic, thermal insulation performances, safety, •••

[0064] The thickness of the substrate is set according to requirements of applications.

[0065] The substrate, especially a 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 substrate 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, •••

[0066] 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.<Coating system>

[0067] 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.

[0068] 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 surface of the substrate.

[0069] 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.

[0070] 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.

[0071] The coating system 2 can be made of layers of different materials and at least one of these layers 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.

[0072] 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 techniquessuch 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.

[0073] 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.

[0074] 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.

[0075] 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.

[0076] 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.

[0077] 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.

[0078] In some embodiments, the glazing unit can comprise several coating systems applied on same or different surface(s) of a glass sheet.

[0079] 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.< First area >

[0080] According to the invention, the coated substrate 100 comprises a first area 21 defined in the coating system.

[0081] The first area 21 comprises non-conductive or substantially non- conductive line segments marked in the coating system. In Fig. 1, said linesegments are in white colour while in FIG. 2 to FIG. 6, said line segments are in black colour.

[0082] In the sense of the present invention, “Substantially non-conductive line segments" refers to line segments that are at least 90% non-conductive, meaning that no more than 10% of the material may exhibit conductive properties, preferably line segments that are at least 95% non-conductive, meaning that no more than 5% of the material may exhibit conductive properties.

[0083] Said non-conductive or substantially non-conductive line segments are interconnected to form a grid or a mesh having cells.

[0084] In the sense of the present invention, a grid or a mesh consists of intersecting decoated line segments that form a regular or irregular pattern. A grid or a mesh is a pattern where specific regions of the coating system are removed (decoated) to form a network of line segments.

[0085] In some preferred embodiments, to facilitate the decoating process while optimizing the EM transparency, the non-conductive or substantially non- conductive line segments form the same decoated pattern meaning a regular grid or a regular mesh.

[0086] 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.

[0087] In some embodiments, as illustrated in FIG. 2, the grid / mesh is a partially opened grid / mesh meaning that at a border the grid / mesh has a rack design 213 and line segments extends from the last interactions with another line segment.

[0088] Preferably, the grid meshes has a distance between the line segments that is significantly smaller than the wavelength of the desired electromagnetic waves in question. To that end, the metal-containing 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.

[0089] Preferably, the line segments can be arranged in various geometric shapes such as squares, rectangles, hexagons, or other polygons. Line segments are typically very narrow, with widths ranging from 10 pm to 300 pm, andpreferably from 15 pm to 150 pm, more preferably between 20 pm and 60 pm, and even more preferably substantially 35 pm. This ensures that the lines are visually unobtrusive and do not significantly impair the optical clarity of the substrate.

[0090] In some embodiments where the line segments form a square grid / mesh, the squares, as illustrated in FIG. 2 to FIG. 6, the cells 211, 212, 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 effective wavelength to let pass through the glazing unit.

[0091] In some embodiments, as illustrated in FIG. 4, some of the cells 212 can have different size than others 211. 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.< Second area >

[0092] Coming back to FIG. 1, the coated substrate 100 also comprises a second area 22 defined in the coating system. The second area consists of a two- dimensional array of isolated patches of the coating system 221, 222, 223, 224, 225, 226, 227, 228, 229, 230, 231. Each of the isolated patches is isolated from each other by a portion of the first area.

[0093] As illustrated in FIG. 1 to FIG. 6, each of the isolated patches is isolated from each other by a portion of the first area. It means that each of the isolated patches are separated by at least one cell of the grid, preferably several cells separate two adjacent patches.

[0094] As illustrated in FIG. 2, each 221, 222, 223, 224, 225, 226, 227, 228, 229, 230, 231 of the isolated patches can have a generic and different shape. Each shape is defined by the edge with the first area.

[0095] According to the invention, the second area has no non-conductive or substantially non-conductive line segment connecting a line of the first area. It means that even if a patch 226 comprises at least a line segment 254, to enlarge the frequency range (of the effective wavelength) transparency, said line segment 254 should be isolated from the line segment of the first area 21 and cannot be connected to one of the line segments of the first area 21.

[0096] In Fig. 2, some other embodiments are shown. Line segments 251, 252 of the first area can define a recess in a patch 221, 222, 225, 228, 229, 230, 231,232 to fine tune the transmission of the RF signal. The surface of the patch is the surface defines between the line segments of the first area meaning that the extensions of the first area is not considered to measure the surface of the patch.

[0097] It is understood that the second area is defined by the union of the surface of each of the isolated patches.

[0098] According to the invention, the surface of each of the isolated patch is at least three times larger than the mean of the surface of the cells as illustrated in different figures, preferably, the surface of each of the isolated patch is at least four times larger than the mean of the surface of the cells. The surface of each of the isolated patch compared to the surface of the cells depends on the frequency range and on the desire application.

[0099] According to the invention, the array of isolated patches means that the isolated patches are arranged in rows and columns as illustrated in figures; each row and each column being separated to respectively another row or column by the first area.<lsolated patch>

[0100] In some preferred embodiments, as illustrated in FIG. 3 to FIG. 6, the isolated patches have same generic shape to facilitate the decoating process while improving the interaction between isolated patches.

[0101] 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.

[0102] In some preferred embodiments, to engineer the EM transparency the array of the isolated patches forms a periodic array. That means that the outer contour, the shape, 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.

[0103] In some preferred embodiments as illustrated in FIG. 5, the array of isolated patches forms a period array of isolated patches having the same cross shape with the same dimensions to specifically balance between the rejection at that specific portion of the defined frequency range and the transmission at the rest of frequencies of interest.

[0104] In a specific embodiment, in which the frequency of band rejection is about 419 MHz, the array is a periodic array of isolated patches. Each of the isolated patches has the same cross shape. The length of the cross is about 118 mm (the four branches have the same dimensions), the width of the cross is about 4mm. The decoating pattern of the first area is a square grid of 2x2mm. The distance between the corresponding point of two adjacent cross is about 120 mm.

[0105] To facilitate the manufacture of the coated structure of the present invention, in some embodiments, the generic shape can be a rectangle meaning that non-conductive or substantially non-conductive line segments define rectangular patches. In some specific embodiments of such embodiments, the array can comprise isolated patches with different rectangle dimensions.

[0106] 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.

[0107] The position and the general size of the first and second areas on the coating system can depend on the desired application.

[0108] According to the invention, non-conductive or substantially non- conductive line segment in the form of grid lines arranged in a mesh-like manner form a low-pass frequency surface (FSS) in the first area.

[0109] According to the invention, the first area and the second area form together a low-pass FSS with band-rejection features in the coating system.

[0110] In some preferred embodiments, the non-conductive or substantially non- conductive line segments form a rectangular 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.

[0111] In some embodiments, some of line segments can close the grid / mesh to form a partially closed grid / mesh as illustrated in FIG. 2 with the line segments213 and preferably, in such embodiments, the grid / mesh is a fully closed grid / mesh.

[0112] 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.

[0113] In some preferred embodiments, as illustrated in FIG. 2 to FIG. 6, the two- dimensional array of isolated patches comprises at least two rows, preferably the two-dimensional array of isolated patches comprises at least three rows, more preferably the two-dimensional array of isolated patches comprises at least four rows. This permits to increase the EM transparency.

[0114] In some preferred embodiments, as illustrated in FIG. 2 to FIG. 6, the two- dimensional array of isolated patches comprises at least two columns, preferably the two-dimensional array of isolated patches comprises at least three columns, more preferably the two-dimensional array of isolated patches comprises at least four columns. This permits to increase the EM transparency.

[0115] FIG. 3 illustrates some embodiments in which the isolated patches are rectangular, and the array is periodic.

[0116] FIG. 5 illustrates some embodiments in which the isolated patches have a cross shape, especially a plus sign shape or shape of Jerusalem Cross, and the array is periodic.

[0117] FIG. 6 illustrates some embodiments in which some of the isolated patches 221, 224, 225, 228 are only partially surrounded by the first area. In such embodiments, each of the isolated patches are separated by the first area.

[0118] FIG. 7, illustrating the fifth aspect of the present invention, shows a mobile object, a train 200, having side windows 201, 202, 203, 204, ••• Due to the Faraday cage effect between the metallic carbody and the coated windows, the indoor connectivity is really poor. To improve this connectivity, said windows should be transformed into coated structure according to the first aspect of the present invention.

[0119] To transform a window into a coated structure in a mobile object or in a stationary object, the present invention proposes several methods.

[0120] A first method is to install coated structures according to the invention directly during the assembly of the object.

[0121] A second method is to replace an existing window by a coated structure according to the present invention.

[0122] Another way to transform a window to a coated structure, is to modify the window in a factory or in situ.

[0123] 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 the first area by creating non-conductive or substantially non-conductive line segments surrounding at least partially an array of isolated patches of the coating system. This creation step 803 can be performed in a factory or in situ with a decoating apparatus. This method can be used to transform an existing window to a coated structure, steps 801 and 802 being used to create such window.

[0124] The step 803 can be made by masking the second area and / or by adapting the decoating path to avoid the second area.

[0125] 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.

[0126] The decoating apparatus can also stand in front of the glazing unit to decoat.

[0127] Some exemplary decoating apparatus are described in W02015050762, WO2022112532, WO2021165064, WO2021165065,WO2021239603, WO2022079225, WO2022112530, WO2022112529,WO2022112521.

[0128] 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.

[0129] 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.

[0130] 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 the first area having non-conductive or substantially non-conductive line segments surrounding at least partially an array of isolated patches of the coating system.

[0131] The mask can be removed by heating, by cleaning, by mechanical actions, by acid or any other suitable manner to remove a temporary mask.

[0132] The present invention also related to the use of a coated structure according to the first aspect in a stationary or mobile object to improve the connectivity inside said object.

[0133] 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.

Claims

ClaimsClaim 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 having a transmission with an attenuation up to 20 decibels (dB) or more; the coating system being 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 characterized in that the second area consists of a two-dimensional array of isolated patches of the coating system (221, 222, 223, 224, 225, 226, 227, 228, 229, 230, 231); each of the isolated patches is isolated from each other by a portion of the first area; in that the first area comprises non-conductive or substantially non- conductive line segments marked in the coating system; said non- conductive or substantially non-conductive line segments are interconnected to form a grid or a mesh having cells; in that the second area has no non-conductive or substantially non- conductive line segment connected to a line of the first area; and in that the surface of each of the isolated patch is at least three times larger than the mean of the surface of the cells.Claim 2. Coated structure according to claim 1, wherein each of the isolated patches has the same generic shape.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 claims 2 or 3, wherein the generic shape is a cross.Claim 5. Coated structure according to claim 4, 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 claims 1 - 5, wherein cells of the grid or the mesh, are rectangular cells, preferably cells of the grid or the mesh, are square cells.Claim 7. Coated structure according to claims 1 - 6, wherein the substrate comprises a glazing panel.Claim 8. Coated structure according to claims 1 - 6, wherein the substrate is a plastic-based substrate.Claim 9. Coated structure according to claims 1 - 8, wherein the two- dimensional array of isolated patches comprises at least two rows, preferably the two-dimensional array of isolated patches comprises at least three rows, more preferably the two-dimensional array of isolated patches comprises at least four rows.Claim 10. Coated structure according to claims 1 - 9, wherein the two- dimensional array of isolated patches comprises at least two columns, preferably the two-dimensional array of isolated patches comprises at least three columns, more preferably the two-dimensional array of isolated patches comprises at least four columns.Claim 11. Coated structure according to claims 1 - 10, wherein the surface of each of the isolated patch is at least four times larger than the mean of the surface of the cells, preferably the surface of each of the isolated patch is at least nine times larger than the mean of the surface of the cells, more preferably the surface of each of the isolated patch is at least sixteen times larger than the mean of the surface of the cells.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 substrateA2. 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 first area by creating non-conductive or substantially non-conductive line segments surrounding at least partially an array of isolated patches of the coating system.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. Second manufacturing method to produce a coated structure according to claims 1-11, the second manufacturing method comprises the following steps:Bl. Providing a substrateB2. Masking the substrate with a maskB3. 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 the first area having non-conductive or substantially non-conductive line segments surrounding at least partially an array of isolated patches of the coating system.

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