Reflective tile, tiled frequency selective reflective construction, and wireless system

Abstract

A tiled frequency selective reflective construction includes a plurality of reflective tiles. The plurality of reflective tiles is arranged along mutually orthogonal in-plane first and second directions. Each of the reflective tiles includes a plurality of spaced apart electrically isolated metallic elements forming mutually orthogonal rows and columns of the metallic elements. Each of the metallic elements has an average in-plane outermost radius, such that for at least a first row of the metallic elements, a first plot of the radius versus a location of the metallic elements along the first row includes a first global peak radius at a first location, a local peak radius at a second location, and a first global minimum radius at a third location between the first and second locations.

Description

[0001] REFLECTIVE TILE, TILED FREQUENCY SELECTIVE REFLECTIVE CONSTRUCTION, AND WIRELESS SYSTEM

[0002] Technical Field

[0003] The present disclosure relates to a reflective tile and a tiled frequency selective reflective construction including the reflective tile. The present disclosure further relates to a wireless system including the tiled frequency selective reflective construction.

[0004] Background

[0005] Mobile and wireless communications use radio frequency (RF) waves. Such communications are used within or outside different structures, such as buildings, and the like. Due to a variety of structures or complex designs, the RF waves may be attenuated or may not be able to cover a desired area.

[0006] Summary

[0007] In a first aspect, the present disclosure provides a tiled frequency selective reflective construction. The tiled frequency selective reflective construction includes a plurality of reflective tiles arranged along mutually orthogonal in-plane first and second directions. Each of the reflective tiles includes a plurality of spaced apart electrically isolated metallic elements forming mutually orthogonal rows and columns of the metallic elements. Each of the metallic elements has an average in-plane outermost radius, such that for at least a first row of the metallic elements, a first plot of the radius versus a location of the metallic elements along the first row comprises a first global peak radius at a first location, a local peak radius at a second location, and a first global minimum radius at a third location between the first and second locations.

[0008] In a second aspect, the present disclosure provides a wireless system. The wireless system includes spaced apart first transceiver configured to at least emit a radiofrequency (RF) electromagnetic wave having a free-space wavelength in a range from about 1.0 millimeter (mm) to about 300 centimeters (cm), and a plurality of spaced apart second transceivers, each configured to at least receive an RF electromagnetic wave having the free-space wavelength. The wireless system further includes the tiled frequency selective reflective construction of the first aspect configured to receive the emitted RF electromagnetic wave emitted by the first transceiver and diffusely reflect at least a portion of the received RF electromagnetic wave so that a first portion of the diffusely reflected RF electromagnetic wave is received by one of the second transceivers and a second portion of the diffusely reflected RF electromagnetic wave is received by one other of the second transceivers.

[0009] In a third aspect, the present disclosure provides a reflective tile for use in a tiled frequency selective reflective construction. The reflective tile includes a major surface including non-overlapping first through fourth surface portions. The first, second, and third surface portions define, and are continuous without any surface opening, within closed respective first, second, and third outermost perimeters. The fourth surface portion defines, and is continuous without any surface opening between, continuous closed fourth outermost and innermost perimeters. The first outermost and the fourth innermost perimeters are mutually coincident with each other. Portions of the second outermost perimeter are coincident with respective portions of the third and the fourth outermost perimeters so that the second surface portion completely isolates the third and fourth surface portions from each other. The reflective tile further includes a plurality of spaced apart electrically isolated metallic elements two- dimensionally arranged in, and numbering at least 10 in total in, each of the first through fourth surface portions. Each of the metallic elements has a largest lateral dimension. Each of the metallic elements in the first and second surface portions has a greater largest lateral dimension than each of the metallic elements in the third and fourth surface portions.

[0010] In a fourth aspect, the present disclosure further provides a reflective tile for use in a tiled frequency selective reflective construction. The reflective tile includes a major surface having at least one continuous primary surface portion that has no surface openings, disposed in an interior of the major surface, and has a continuous closed outer perimeter. The primary surface portion is divided into a plurality of alternating first and second secondary surface portions numbering at least 3 in total. Each of the first and second secondary surface portions is continuous without any surface opening and has a continuous closed outer perimeter that coincides with a portion of the closed outer perimeter of either an adjacent secondary surface portion or the primary surface portion. Each of the first and second secondary surface portions includes at least 10 spaced apart electrically isolated electrically conductive elements arranged two-dimensionally across the secondary surface portion. The electrically conductive elements have an average largest lateral dimension Dlavg in each of the first secondary surface portions and an average largest lateral dimension D2avg in each of the second secondary surface portion, where Dlavg > D2avg.

[0011] In a fifth aspect, the present disclosure further provides a tiled frequency selective reflective construction including a plurality of the reflective tiles of the fourth aspect arranged at least in a row so that when a substantially collimated incident RF electromagnetic wave having a free-space wavelength in a range from about 1.0 mm to about 300 cm is incident on the tiled frequency selective reflective construction at an incident angle in a range from about zero degree to about 70 degrees, then each of the reflective tiles diffusely reflects at least a portion of the incident RF electromagnetic wave. The diffusely reflected RF electromagnetic wave has a peak intensity propagating along a reflected direction. The reflected direction of at least a first one of the reflective tiles is different from the reflected direction of at least a second one of the reflective tiles.

[0012] In a sixth aspect, the present disclosure further provides a reflective tile for use in a tiled frequency selective reflective construction. The reflective tile includes a plurality of spaced apart electrically isolated metallic elements forming mutually orthogonal rows and columns of the metallic elements. Each of the metallic elements has an average in-plane outermost radius, such that for at least a first row of the metallic elements, a first plot of the radius versus a location of the metallic elements along the first row includes a plurality of alternating peaks and valleys numbering at least 10 in total. A highest peak and a lowest valley in the plurality of alternating peaks and valleys have respective radii Sir and S2r, where Slr / S2r > 2.

[0013] The details of one or more examples of the disclosure are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the disclosure will be apparent from the description and drawings, and from the claims.

[0014] Brief Description of the Drawings

[0015] Exemplary embodiments disclosed herein may be more completely understood in consideration of the following detailed description in connection with the following figures. The figures are not necessarily drawn to scale. Like numbers used in the figures refer to like components. However, it will be understood that the use of a number to refer to a component in a given figure is not intended to limit the component in another figure labeled with the same number.

[0016] FIG. 1 shows a schematic top view of a tiled frequency selective reflective construction, according to an embodiment of the present disclosure;

[0017] FIG. 2A shows a schematic sectional view of a reflective tile of the tiled frequency selective reflective construction, according to an embodiment of the present disclosure;

[0018] FIG. 2B shows a schematic sectional view of a reflective tile of the tiled frequency selective reflective construction, according to another embodiment of the present disclosure;

[0019] FIGS. 3 A shows a schematic top view of a metallic element of the reflective tile, according to an embodiment of the present disclosure;

[0020] FIGS. 3B and 3C show schematic views of different shapes of the metallic elements of the reflective tile, according to other embodiments of the present disclosure;

[0021] FIG. 4 shows a schematic top view of a reflective tile, according to an embodiment of the present disclosure;

[0022] FIG. 5 shows a schematic top view of a reflective tile, according to another embodiment of the present disclosure;

[0023] FIG. 6 shows a schematic top view of a reflective tile, according to yet another embodiment of the present disclosure;

[0024] FIGS. 7 A and 7B show schematic views of different reflective tiles for use in the tiled frequency selective reflective construction, according to an embodiment of the present disclosure;

[0025] FIGS. 8 A and 8B show graphs depicting variations in a radius versus a location of the metallic elements in the reflective tile of FIG. 4, according to an embodiment of the present disclosure;

[0026] FIG. 9 shows a graph depicting a change in the radius of the metallic elements in adj acent rows and adjacent columns of the reflective tile of FIG. 4, according to an embodiment of the present disclosure; FIG. 10 shows a graph depicting variations in a radius versus a location of the metallic elements in the reflective tile of FIG. 6, according to an embodiment of the present disclosure;

[0027] FIG. 11A shows a substantially collimated substantially planar radiofrequency (RF) electromagnetic wave incident at an incident angle on the reflective tile of FIG. 4, according to an embodiment of the present disclosure;

[0028] FIG. 11B shows a substantially collimated substantially planar substantially normally incident RF electromagnetic wave incident on the reflective tile of FIG. 6, according to an embodiment of the present disclosure;

[0029] FIG. 11C shows a graph depicting reflection coefficient distributions of the reflective tiles of FIGS. 4 and 6 versus reflection angles, according to an embodiment of the present disclosure;

[0030] FIGS. 12A and 12B show schematic top and side views, respectively, of a tiled frequency selective reflective construction, according to another embodiment of the present disclosure; and

[0031] FIG. 13 shows a schematic view of a wireless system, according to an embodiment of the present disclosure.

[0032] Detailed Description

[0033] In the following description, reference is made to the accompanying figures that form a part thereof and in which various embodiments are shown by way of illustration. It is to be understood that other embodiments are contemplated and may be made without departing from the scope or spirit of the present disclosure. The following detailed description, therefore, is not to be taken in a limiting sense.

[0034] In the following disclosure, the following definitions are adopted.

[0035] As used herein, all numbers should be considered modified by the term “about”. As used herein, “a,” “an,” “the,” “at least one,” and “one or more” are used interchangeably.

[0036] As used herein as a modifier to a property or attribute, the term “generally”, unless otherwise specifically defined, means that the property or attribute would be readily recognizable by a person of ordinary skill but without requiring absolute precision or a perfect match (e.g., within + / - 20 % for quantifiable properties).

[0037] The term “substantially”, unless otherwise specifically defined, means to a high degree of approximation (e.g., within + / - 10% for quantifiable properties) but again without requiring absolute precision or a perfect match.

[0038] The term “about”, unless otherwise specifically defined, means to a high degree of approximation (e.g., within + / - 5% for quantifiable properties) but again without requiring absolute precision or a perfect match.

[0039] As used herein, the terms “first” and “second” are used as identifiers. Therefore, such terms should not be construed as limiting of this disclosure. The terms “first” and “second” when used in conjunction with a feature or an element can be interchanged throughout the embodiments of this disclosure.

[0040] As used herein, “at least one of A and B” should be understood to mean “only A, only B, or both A and B”.

[0041] Mobile and wireless communications use radiofrequency (RF) waves. Such communications are used within or outside different structures, such as buildings, and the like. Due to a variety of structures or complex designs, the RF waves may be attenuated or may not be able to cover a desired area. Signal shadowing and / or a limited number of available multipath components may negatively affect a coverage of the RF waves. Further, using highly discretized beams may negatively affect a network performance. Moreover, signal backscattered to antenna (e.g., from walls or other objects) may limit a dynamic range of the antenna. Further, antenna sidelobes may cause electromagnetic field (EMF) safety issues.

[0042] The present disclosure relates to a reflective tile. The present disclosure further relates to a tiled frequency selective reflective construction including the reflective tile. The present disclosure further relates to a wireless system including the tiled frequency selective reflective construction.

[0043] The tiled frequency selective reflective construction includes a plurality of reflective tiles arranged along mutually orthogonal in-plane first and second directions. Each of the reflective tiles includes a plurality of spaced apart electrically isolated metallic elements forming mutually orthogonal rows and columns of the metallic elements. Each of the metallic elements has an average in-plane outermost radius, such that for at least a first row of the metallic elements, a first plot of the radius versus a location of the metallic elements along the first row comprises a first global peak radius at a first location, a local peak radius at a second location, and a first global minimum radius at a third location between the first and second locations.

[0044] The wireless system includes spaced apart first transceiver configured to at least emit a RF electromagnetic wave having a free-space wavelength in a range from about 1.0 millimeter (mm) to about 300 centimeters (cm), and a plurality of spaced apart second transceivers, each configured to at least receive an RF electromagnetic wave having the free-space wavelength. The wireless system further includes the tiled frequency selective reflective construction configured to receive the emitted RF electromagnetic wave emitted by the first transceiver and diffusely reflect at least a portion of the received RF electromagnetic wave so that a first portion of the diffusely reflected RF electromagnetic wave is received by one of the second transceivers and a second portion of the diffusely reflected RF electromagnetic wave is received by one other of the second transceivers.

[0045] The tiled frequency selective reflective construction including the plurality of reflective tiles may be configured to diffusely scatter or diffusely reflect the emitted RF electromagnetic wave emitted by the first transceiver. This may provide a beam broadening functionality, as per desired application attributes. Thus, a usage of the tiled frequency selective reflective construction of the present disclosure may provide a better RF coverage and may reduce RF attenuation issues. Referring now to figures, FIG. 1 is a schematic top view of a tiled frequency selective reflective construction 300, according to an embodiment of the present disclosure.

[0046] The tiled frequency selective reflective construction 300 defines mutually orthogonal x, y, and z-axes. The x and y-axes are in-plane axes of the tiled frequency selective reflective construction 300, while the z-axis is a transverse axis disposed along a thickness of the tiled frequency selective reflective construction 300. In other words, the x and y-axes are disposed along a plane of the tiled frequency selective reflective construction 300, while the z-axis is perpendicular to the plane of the tiled frequency selective reflective construction 300. In some embodiments, the tiled frequency selective reflective construction 300 is formed to have a non-planar shape.

[0047] The tiled frequency selective reflective construction 300 includes a plurality of reflective tiles 200. The plurality of reflective tiles 200 is arranged along mutually orthogonal in-plane first and second directions. In some embodiments, the first direction may be defined substantially along the x-axis and the second direction may be defined substantially along the y-axis. In the illustrated embodiment of FIG. 1, the plurality of reflective tiles 200 is arranged along the x-axis and the y-axis. In some embodiments, the reflective tile 200 may be interchangeably referred to as “the tile 200” herein.

[0048] FIG. 2A is a schematic sectional view of the reflective tile 200, according to an embodiment of the present disclosure. FIG. 2B is a schematic sectional view of the reflective tile 200, according to another embodiment of the present disclosure.

[0049] Referring to FIGS. 1, 2A and 2B, each of the plurality of reflective tiles 200 includes a plurality of spaced apart electrically isolated metallic elements 10. In some embodiments, the spaced apart electrically isolated metallic elements 10 may be interchangeably referred to as “the metallic elements 10” herein. In some embodiments, the spaced apart electrically isolated metallic elements 10 may be interchangeably referred to as “the electrically isolated electrically conductive elements 10” herein. In some embodiments, the metallic elements 10 of each of the tiles 200 include one or more of gold, silver, copper, aluminum, and titanium.

[0050] The plurality of spaced apart electrically isolated metallic elements 10 forms mutually orthogonal rows and columns of the metallic elements 10. In some embodiments, the rows of the metallic elements 10 extend substantially along the x-axis and the columns of the metallic elements 10 extend substantially along the y-axis. In some embodiments, the metallic elements 10 form a two- dimensional regular array of the metallic elements 10.

[0051] In some embodiments, each of the tiles 200 has at least 5 rows of the metallic elements 10. In some embodiments, each of the tiles 200 has at least 10, at least 20, at least 30, at least 40, at least 50, at least 60, at least 70, at least 80, at least 90, or at least 100 rows of the metallic elements 10. Further, in some embodiments, each of the tiles 200 has at least 5 columns of the metallic elements 10. In some embodiments, each of the tiles 200 has at least 10, at least 20, at least 30, at least 40, at least 50, at least 60, at least 70, at least 80, at least 90, or at least 100 columns of the metallic elements 10. In some embodiments, the metallic elements 10 are disposed on a substrate 12. In some embodiments, the substrate 12 includes one or more of a polyethylene terephthalate (PET), a polyethylene naphthalate (PEN), an acrylic -based polymer, a butyrate-based polymer, a polycarbonate, a polycarbonate copolymers, a polyurethane, a polyvinyl chloride (PVC), a polyimide (PI), a polyethersulfone, a polyethylene, a polypropylene, a polylactic acid, a fluoro-based polymer, or a co- PET, a poly vinylidene fluoride-based polymer, a terpolymerbased polymer, a tetrafluoroethylene-based polymer, a hexafluoropropylene-based polymer, and a vinylidene fluoride-based polymer.

[0052] In some embodiments, at least one metallic element 10 of the metallic elements 10 is at least partially embedded in an adjacent layer (e.g., the substrate 12) adjacent to the metallic elements 10. In some embodiments, the substrate 12 may be interchangeably referred to as “the adjacent layer 12” herein.

[0053] As illustrated in FIG. 2B, at least one metallic element 10g of the metallic elements 10 is at least partially embedded in the adjacent layer 12 adjacent to the metallic elements 10. In some embodiments, the adjacent layer 12 is an adhesive layer. Further, in some embodiments, as illustrated in FIG. 2B, at least one metallic element lOh of the metallic elements 10 is substantially fully embedded in the adjacent layer 12 adjacent to the metallic elements 10.

[0054] In some embodiments, the metallic elements 10 of the tiles 200 have thicknesses lOt in a range from about 10 nanometers (nm) to about 1 millimeter (mm). In the illustrated embodiment of FIG. 2B, the thicknesses lOt of the metallic elements 10 extend substantially along the z-axis. Further, in some embodiments, the metallic elements 10 of the tiles 200 have substantially the same thickness lOt (i.e., substantially along the z-axis).

[0055] FIG. 2A further illustrates a substantially normally incident light 40 having a first visible wavelength in a visible wavelength range extending from about 420 nm to about 680 nm.

[0056] Referring to FIGS. 1 and 2 A, for the substantially normally incident light 40 having the first visible wavelength, each of the tiles 200 has an optical transmittance of greater than about 10%. In some embodiments, for the substantially normally incident light 40 having the first visible wavelength, each of the tiles 200 has the optical transmittance of greater than about 20%, greater than about 30%, greater than about 40%, greater than about 50%, greater than about 60%, greater than about 70%, or greater than about 80%. In an example, the first wavelength is about 550 nm.

[0057] FIG. 2B further illustrates a substantially collimated incident RF electromagnetic wave 41 having a free-space wavelength in a range from about 1.0 mm to about 300 centimeters (cm) and a corresponding reflected wave 42 and a diffuse wave 43. In some embodiments, the free-space wavelength is in the range from about 1.0 mm to about 250 cm, about 1.0 mm to about 200 cm, about 1.0 mm to about 150 cm, about 1.0 mm to about 100 cm, about 1.0 mm to about 80 cm, about 1.0 mm to about 60 cm, about 1.0 mm to about 40 cm, or about 1.0 mm to about 20 cm.

[0058] Referring to FIG. 1 and 2B, in some embodiments, for the substantially collimated incident RF electromagnetic wave 41 and for at least one incident angle al in a range from about zero degree to

[0059] -1 - about 70 degrees, each of the tiles 200 has a specular reflectance of less than about 70% and a diffuse reflectance of greater than about 5%.

[0060] In some embodiments, for the substantially collimated incident RF electromagnetic wave 41 and for the at least one incident angle al, each of the tiles 200 has the specular reflectance of less than about 65%, less than about 60%, less than about 55%, less than about 50%, less than about 45%, less than about 40%, less than about 35%, less than about 30%, less than about 25%, or less than about 20%, and the diffuse reflectance of greater than about 10%, greater than about 15%, greater than about 20%, greater than about 25%, greater than about 30%, greater than about 35%, greater than about 40%, greater than about 45%, greater than about 50%, greater than about 55%, or greater than about 60%.

[0061] In some embodiments, each of the tiles 200 has a multilayer structure. Specifically, in some embodiments, each of the tiles 200 includes a frequency selective surface (FSS) layer, a dielectric layer, and a ground plane layer. In some embodiments, the FSS layer is disposed on a first major surface of the dielectric layer and the ground plane layer is disposed on a second major surface of the dielectric layer opposite to the first major surface of the dielectric layer. The FSS layer includes the metallic elements 10. In some embodiments, the dielectric layer includes the substrate 12.

[0062] FIG. 3A is a schematic top view of the metallic element 10, according to an embodiment of the present disclosure.

[0063] In some embodiments, at least one of the metallic elements 10 of at least one of the tiles 200 (shown in FIG. 2A) is an annulus. In such cases, the metallic element 10 may be interchangeably referred to as “the annulus 10”. In some embodiments, an average thickness lOw of a wall of the annulus 10 is between about 10 microns to about 2.5 cm.

[0064] Referring to FIG. 3A, in some embodiments, each of the metallic elements 10 has an average in-plane outermost radius r. As shown in the illustrated embodiment of FIG. 3 A, each of the metallic elements 10 may have a diameter D, that is equal to two times of the outermost radius r.

[0065] In some embodiments, the metallic elements 10 of the tiles 200 have the radii r in a range from about 10 nm to about 5 cm. In some embodiments, the metallic elements 10 of the tiles 200 have the radii r in the range from about 100 nm to about 1 cm, about 1 micron to about 100 mm, about 10 microns to about 100 mm, about 0.01 mm to about 50 mm, about 0.05 mm to about 50 mm, or about 0.05 mm to about 10 mm.

[0066] In some embodiments, a ratio of a maximum radius to a minimum radius of the metallic elements 10 in each of the tiles 200 is greater than about 1.1. In some embodiments, the ratio of the maximum radius to the minimum radius of the metallic elements 10 in each of the tiles 200 is greater than about 1.5, greater than about 2, greater than about 4, greater than about 6, greater than about 8, greater than about 10, greater than about 15, greater than about 20, or greater than about 50.

[0067] FIGS. 3B and 3C are schematic views of different shapes of the metallic element 10, according to an embodiment of the present disclosure. FIG. 3B illustrates different shapes of the at least one of the annuluses 10 of the at least one of the tiles 200 (shown in FIG. 2A). In some embodiments, the annulus 10 has a circular shape 10a (as shown in FIG. 3A). In some embodiments, the annulus 10 has an oval shape 10b. In some embodiments, the annulus 10 has a polygonal shape 10c. In some embodiments, the annulus 10 has a curvilinear shape lOd. In some embodiments, the annulus 10 has a piecewise linear shape lOe. In some embodiments, the annulus 10 has a piecewise curved shape lOf.

[0068] Referring to FIG. 3C, in some embodiments, a shape of at least one of the metallic elements 10 of at least one of the tiles 200 is a disc I la, a cube 11b, a rectangular parallelepiped 11c, and a right prism lid.

[0069] FIG. 4 is a schematic top view of a reflective tile 200a similar to the reflective tile 200 for use in the tiled frequency selective reflective construction 300 shown in FIG. 1, according to an embodiment of the present disclosure.

[0070] The reflective tile 200a includes a major surface 30. As discussed above, the plurality of spaced apart electrically isolated metallic elements 10 form the rows along the x-axis and the columns along the y-axis of the metallic elements 10. In the illustrated embodiment of FIG. 4, the tile 200a has at least a first row 15 of the metallic elements 10 extending along the x-axis, and at least a first column 17 of the metallic elements 10 extending along the y-axis. Specifically, in the illustrated embodiment of FIG. 4, the first row 15 extends along the x-axis and passes through a center of the tile 200a and the first column 17 extends along the y-axis and passes through the center of the tile 200a. The center of the tile 200a is represented as a point on the tile 200a, where x=0, y=0, and the z-axis extends perpendicular to the x-y plane. In some embodiments, the first row 15 may be interchangeably referred to as “the central row 15”.

[0071] In some embodiments, the plurality of spaced apart electrically isolated metallic elements 10 of each of the tiles 200a has a 2-fold axis of symmetry substantially orthogonal to the tile 200a (i.e., along the z-axis, x=0, y=0). In the illustrated embodiment of FIG. 4, the plurality of spaced apart electrically isolated metallic elements 10 of each of the tiles 200a has the z-axis as the 2-fold axis of symmetry that is substantially orthogonal to the tile 200a.

[0072] In some embodiments, the plurality of spaced apart electrically isolated metallic elements 10 of each of the tiles 200a has at least one 2-fold axis of symmetry substantially parallel to the tile 200a (i.e., along the x-axis, y=0, z=0; and / or along the y-axis, x=0, z=0). In the illustrated embodiment of FIG. 4, the plurality of spaced apart electrically isolated metallic elements 10 of each of the tiles 200a has at least one of the x-axis and the y-axis as the at least one 2-fold axis of symmetry that is substantially parallel to the tile 200a. In some embodiments, the plurality of spaced apart electrically isolated metallic elements 10 of each of the tiles 200a has two 2-fold axes of symmetry substantially parallel to the tile 200a (i.e., along the x-axis, y=0, z=0; and along the y-axis, x=0, z=0). In the illustrated embodiment of FIG. 4, the plurality of spaced apart electrically isolated metallic elements 10 of each of the tiles 200a has the x-axis and the y-axis as the two 2-fold axes of symmetry that are substantially parallel to the tile 200a.

[0073] FIG. 5 is a schematic view of a reflective tile 200b similar to the reflective tile 200 for use in the tiled frequency selective reflective construction 300 shown in FIG. 1, according to another embodiment of the present disclosure.

[0074] The tile 200b also includes the major surface 30 and the plurality of spaced apart electrically isolated metallic elements 10. The major surface 30 includes non-overlapping first through fourth surface portions 31, 32, 33, 34. Specifically, the major surface 30 includes the first surface portion 31, the second surface portion 32, the third surface portion 33, and the fourth surface portion 34.

[0075] The first, second, and third surface portions 31, 32, 33 define, and are continuous without any surface opening, within closed respective first, second, and third outermost perimeters 31a, 32a, 33a. In other words, the first, second, and third surface portions 31, 32, 33 are continuous surface portions without any through-holes or through-openings therewithin.

[0076] The fourth surface portion 34 defines, and is continuous without any surface opening between, continuous closed fourth outermost and innermost perimeters 34a, 34b. In other words, the fourth surface portion 34 is also a continuous surface portion without any through-holes or through-openings therewithin.

[0077] The first outermost perimeter 31a and the fourth innermost perimeter 34b are mutually coincident with each other. Further, portions of the second outermost perimeter 32al, 32a2 are coincident with respective portions of the third and fourth outermost perimeters 33al, 34al so that the second surface portion 32 completely isolates the third and fourth surface portions 33, 34 from each other.

[0078] The tile 200b includes the plurality of spaced apart electrically isolated metallic elements 10 two-dimensionally arranged in, and numbering at least 10 in total in, each of the first through fourth surface portions 31, 32, 33, 34. In some embodiments, the tile 200b includes the plurality of spaced apart electrically isolated metallic elements 10 numbering at least 20, at least 50, at least 100, at least 150, or at least 200 in total in, each of the first through fourth surface portions 31, 32, 33, 34.

[0079] Further, in each of the first through fourth surface portions 31, 32, 33, 34, each of the metallic elements 10 has a largest lateral dimension D (as seen in FIG. 3A). Each of the metallic elements 10 in the first and second surface portions 31, 32 has a greater largest lateral dimension D than each of the metallic elements 10 in the third and fourth surface portions 33, 34.

[0080] In some embodiments, the metallic elements 10 in the first through fourth surface portions 31, 32, 33, 34 have respective average largest lateral dimensions DI, D2, D3, D4. In some embodiments, the average largest lateral dimensions DI, D2 are greater than the average largest lateral dimensions D3, D4, i.e., DI and D2 are greater than D3 and D4 (i.e., DI > D3, DI > D4, D2 > D3, D2 > D4).

[0081] In some embodiments, the first through fourth surface portions 31, 32, 33, 34 have respective total areas Al, A2, A3, A4. In some embodiments, the total area A4 is greater than the total area A3, the total area A3 is greater than the total area Al, and the total area Al is greater than the total area A2, i.e., A4 > A3 > Al > A2.

[0082] FIG. 6 is a reflective tile 200c similar to the reflective tile 200 for use in the tiled frequency selective reflective construction 300 shown in FIG. 1, according to another embodiment of the present disclosure.

[0083] The reflective tile 200c also includes the plurality of spaced apart electrically isolated metallic elements 10 forming the mutually orthogonal rows and columns of the metallic elements 10. In an embodiment, the rows of the metallic elements 10 are formed along the x-axis, and the columns of the metallic elements 10 are formed along the y-axis. Further, each of the metallic elements 10 has the average in-plane outermost radius r. In the illustrated embodiment of FIG. 6, the tile 200c has at least a first row 25 of the metallic elements 10 extending along the x-axis, and at least a first column 27 of the metallic elements 10 extending along the y-axis. Specifically, in the illustrated embodiment of FIG. 6, the first row 25 extends along the x-axis and passes through a center of the tile 200c and the first column 27 extends along the y-axis and passes through the center of the tile 200c. The center of the tile 200c is represented as a point on the tile 200c, where x=0, y=0, and the z-axis extends perpendicular to the x-y plane.

[0084] FIG. 7 A is a schematic top view of the reflective tiles 200a, 200b for use in the tiled frequency selective reflective construction 300, according to an embodiment of the present disclosure. FIG. 7B is a schematic top view of the reflective tile 200c for use in the tiled frequency selective reflective construction 300, according to an embodiment of the present disclosure.

[0085] Referring to FIGS. 7A-7B, the reflective tile 200a, 200b, 200c includes the major surface 30 having at least one continuous primary surface portion that has no surface openings. Specifically, the reflective tile 200a, 200b includes a major surface 60a having at least one continuous primary surface portion 61a that has no surface openings and the reflective tile 200c includes a major surface 60b having at least one continuous primary surface portion 61b that has no surface openings.

[0086] The at least one continuous primary surface portion 61a, 61b is disposed in an interior of the major surface 30, 60a, 60b, and has a continuous closed outer perimeter 62a, 62b. Specifically, the at least one continuous primary surface portion 61a is disposed in the interior of the major surface 60a and has the continuous closed outer perimeter 62a, and the at least one continuous primary surface portion 61b is disposed in the interior of the major surface 60b and has the continuous closed outer perimeter 62b. The at least one continuous primary surface portion 61a, 61b may be interchangeably referred to as “the primary surface portion 61a, 61b”.

[0087] The primary surface portion 61a, 61b is divided into a plurality of alternating first secondary surface portions 63a, 64a and second secondary surface portions 63b, 64b numbering at least 3 in total. Specifically, the primary surface portion 61a is divided into the plurality of alternating first secondary surface portions 63a and the second secondary surface portions 63b numbering at least 3 in total, and the primary surface portion 61b is divided into the plurality of alternating first secondary surface portions 64a and the second secondary surface portions 64b numbering at least 3 in total.

[0088] In some embodiments, the primary surface portion 61a, 61b is divided into the plurality of alternating first secondary surface portions 63a, 64a and second secondary surface portions 63b, 64b numbering at least 4, at least 5, at least 6, at least 7, at least 8, at least 9, at least 10, at least 15, or at least 20 in total.

[0089] Each of the first and second secondary surface portions 63 a, 64a, 63b, 64b are continuous without any surface opening and have a continuous closed outer perimeter 63al, 63bl, 64al, 64bl that coincides with a portion of the closed outer perimeter 63al, 63bl, 64al, 64bl, 62a, 62b of either an adjacent secondary surface portion 63a, 63b, 64a, 64b or the primary surface portion 61a, 61b.

[0090] Specifically, each of the first and second secondary surface portions 63a, 63b, are continuous without any surface opening and have the continuous closed outer perimeter 63al, 63bl that coincides with the portion of the closed outer perimeter 63al, 63bl of either the adjacent secondary surface portion 63 a, 63b or the closed outer perimeter 62a of the primary surface portion 61a.

[0091] Similarly, each of the first and second secondary surface portions 64a, 64b, are continuous without any surface opening and have the continuous closed outer perimeter 64al, 64b 1 that coincides with the portion of the closed outer perimeter 64al, 64bl of either the adjacent secondary surface portion 64a, 64b or the closed outer perimeter 62b of the primary surface portion 61b.

[0092] Each of the first and second secondary surface portions 63a, 64a, 63b, 64b includes at least 10 spaced apart electrically isolated electrically conductive elements 10 (shown in FIG. 2A) arranged two- dimensionally across the first and second secondary surface portions 63 a, 64a, 63b, 64b. In some embodiments, each of the first and second secondary surface portions 63 a, 64a, 63b, 64b includes at least 20, at least 50, at least 100, at least 150, or at least 200 spaced apart electrically isolated electrically conductive elements 10 arranged two-dimensionally across the first and second secondary surface portions 63a, 64a, 63b, 64b.

[0093] The electrically conductive elements 10 have an average largest lateral dimension Dlavg in each of the first secondary surface portions 63 a, 64a and an average largest lateral dimension D2avg in each of the second secondary surface portion 63b, 64b. In some embodiments, the average largest lateral dimension Dlavg of the first secondary surface portions 63a, 64a is greater than the average largest lateral dimension D2avg of the second secondary surface portions 63b, 64b. In other words, Dlavg > D2avg.

[0094] In some embodiments, each of Dlavg and D2avg is in a range from about 10 nm to about 5 cm. In some embodiments, each of Dlavg and D2avg is in the range from about 100 nm to about 1 cm, about 1 micron to about 100 mm, about 10 microns to about 100 mm, about 0.01 mm to about 50 mm, about 0.05 mm to about 50 mm, or about 0.05 mm to about 10 mm.

[0095] FIGS. 8A-8B show graphs 400, 450 depicting variations in the radius r versus a location of the metallic elements 10 in the reflective tile 200a shown in FIG. 4, according to an embodiment of the present disclosure. Specifically, FIG. 8A illustrates the graph 400 depicting a change in the radius r of the metallic elements 10 versus the location on the tile 200a for at least the first row 15 (shown in FIG. 4) of the metallic elements 10 and the first column 17 (shown in FIG. 4) of the metallic elements 10. Further, FIG. 8B illustrates the graph 450 depicting a change in the radius r of the metallic elements 10 versus the location on the tile 200a for different rows of the metallic elements 10 in the tile 200a. Specifically, the graph 450 depicts variations in the radius r of the metallic elements 10 along the y-axis for the different rows in the tile 200a.

[0096] As shown in FIG. 8 A, for at least the first row 15 of the metallic elements 10, a first plot 20 of the radius r versus the location of the metallic elements 10 along the first row 15 includes a first global peak radius Pl at a first location xl, a local peak radius P2 at a second location x2, and a first global minimum radius P3 at a third location x3 between the first and second locations xl, x2.

[0097] The graph 400 further includes a second plot 21 of the radius r versus the location of the metallic elements 10 along the first column 17. The second plot 21 includes a second global peak radius P2’ substantially coincident with the first global peak radius Pl at the first location xl. In some embodiments, the second plot 21 does not include a local peak radius other than the second global peak radius P2’ and does not include a global minimum radius valley.

[0098] Referring to FIG. 8B, the graph 450 includes the first plot 20 for the first row 15 and plots 20b- 20i for the different rows of the tile 200a. In some embodiments, for each of the rows of the metallic elements 10, the plot 20, 20b-20i of the radius r versus the location of the metallic elements 10 along the row includes a global peak Pl, Plb-Pli at a corresponding first location.

[0099] Specifically, the first plot 20 of the radius r versus the location of the metallic elements 10 along the first row 15 includes the first global peak radius Pl at the first location xl, the plot 20b of the radius r versus the location of the metallic elements 10 along another row (e.g., 15throw) includes the global peak Plb at the corresponding first location, the plot 20c of the radius r versus the location of the metallic elements 10 along another row (e.g., 30throw) includes the global peak Pic at the corresponding first location, the plot 20d of the radius r versus the location of the metallic elements 10 along another row (e.g., 45throw) includes the global peak Pld at the corresponding first location, the plot 20e of the radius r versus the location of the metallic elements 10 along another row (e.g., 60throw) includes the global peak Pie at the corresponding first location, the plot 20f of the radius r versus the location of the metallic elements 10 along another row (e.g., 70throw) includes the global peak Plf at the corresponding first location, the plot 20g of the radius r versus the location of the metallic elements 10 along another row (e.g., 75throw) includes the global peak Pig at the corresponding first location, the plot 20h of the radius r versus the location of the metallic elements 10 along another row (e.g., 80throw) includes the global peak Plh at the corresponding first location, and the plot 20i of the radius r versus the location of the metallic elements 10 along another row (e.g., 85throw) includes the global peak Pli at the corresponding first location. In some embodiments, the first global peak Pl and the global peaks Plb-Pli are at the first location xl. In some embodiments, the central row 15 among the rows includes a highest global peak (i.e., the first global peak Pl) among the global peaks Pl, Plb-Pli. In some embodiments, the global peak corresponding to a row that is closer to the central row 15 is higher than the global peak corresponding to a row that is farther from the central row 15. For example, as is apparent from the graph 450, the global peak Plb corresponding to the 15throw that is closer to the central row 15 is higher than the global peak Pic corresponding to the 30throw that is farther from the central row 15.

[0100] FIG. 9 shows a graph 502 depicting change in the radius r of the metallic elements in adjacent rows and adjacent columns of the reflective tile 200a shown in FIG. 4, according to an embodiment of the present disclosure.

[0101] Referring to FIGS. 4, 8A-8B, and 9, the graph 502 depicts the radius r of the metallic elements 10-1 through 10-9 along the x-axis and the radii of the metallic elements 11-2 through 11-9 along the y-axis in the tile 200a and corresponding linear fits 50, 51. Specifically, the radius r of the metallic elements 10-1 through 10-9 along the first row 15 has the linear fit 50 and the radius r of the metallic elements 11-2 through 11-9 along the first column 17 has the linear fit 51.

[0102] In some embodiments, the radius r of the metallic elements 10 decreases at substantially a first linear rate SI’ along the first row 15 from the metallic element 10-1 at the first location xl and across an adjacent sequence of at least 5 adjacent metallic elements 10 (e.g., the metallic elements 10-2 through 10-9) in the first row 15. Further, the radius r of the metallic elements 10 decreases substantially at a second linear rate S2’ along the first column 17 from the metallic element 10-1 at the first location xl and across an adjacent sequence of at least 5 adjacent metallic elements 10 in the first column 17 (e.g., the metallic elements 11-2 through 11-9).

[0103] In some embodiments, the radius r of the metallic elements 10 decreases at substantially the first linear rate SI’ along the first row 15 from the metallic element 10-1 at the first location xl and across the adjacent sequence of at least 6, at least 7, at least 8, at least 9, at least 10, at least 15, or at least 20 adjacent metallic elements 10 in the first row 15. Further, the radius r of the metallic elements 10 decreases substantially at the second linear rate S2’ along the first column 17 from the metallic element 11-2 at the first location xl and across the adjacent sequence of at least 6, at least 7, at least 8, at least 9, at least 10, at least 15, or at least 20 adjacent metallic elements 10 in the first column 17.

[0104] In some embodiments, a ratio of the substantially first linear rate S 1 ’ to the substantially second linear rate S2’ is greater than about 1.2. In other words, S17S2’ > 1.2. In some embodiments, the ratio of the substantially first linear rate SI’ to the substantially second linear rate S2’ is greater than about 1.4, greater than about 1.6, greater than about 1.8, greater than about 2, greater than about 2.2, greater than about 2.4, greater than about 3, greater than about 5, or greater than about 10. In some embodiments, the ratio of the substantially first linear rate SI’ to the substantially second linear rate S2’ is about 2.28.

[0105] In some embodiments, the linear fits 50, 51 have respective r-squared values R1 and R2. Specifically, the linear fit 50 to the radius r of the metallic elements 10 across the adjacent at least 5 metallic elements 10 along the first row 15 has the r-squared value Rl. Further, the linear fit 51 to the radius r of the metallic elements 10 across the adjacent at least 5 metallic elements 10 along the first column 17 has the r-squared value R2. In some embodiments, each of the r-squared values Rl, R2 is greater than about 0.8. In some embodiments, each of the r-squared values Rl, R2 may be greater than about 0.9. In some embodiments, each of the r-squared values Rl, R2 may be greater than about 0.95.

[0106] In an example, the linear fit 50 is according to Equation 1 provided below. y = -0.0073x + 1.205 [Equation 1]

[0107] In Equation 1, y denotes the radius and x denotes the location. In this example, SI’ = -0.0073 and Rl = 0.9726.

[0108] In an example, the linear fit 51 is according to Equation 2 provided below. y = -0.0032x + 1.1977 [Equation 2]

[0109] In Equation 2, y denotes the radius and x denotes the location. In this example, S2’ = -0.0032 and R2 = 0.9513. Therefore, S17S2’ = 2.28.

[0110] FIG. 10 shows a graph 700 depicting variations in the radius r versus a location of the metallic elements 10 in the reflective tile 200c shown in FIG. 6, according to an embodiment of the present disclosure.

[0111] Referring to FIGS. 6 and 10, the graph 700 includes a first plot 80 of the radius r versus the location of the metallic elements 10 along the first row 25. For at least the first row 25 of the metallic elements 10, the first plot 80 includes a plurality of alternating peaks and valleys numbering at least 10 in total. In some embodiments, the first plot 80 of the radius r versus the location of the metallic elements 10 along the first row 25 includes the plurality of alternating peaks and valleys of the metallic elements 10 numbering at least 15, at least 20, or at least 25 in total.

[0112] Further, a highest peak S 1 and a lowest valley S2 in the plurality of alternating peaks and valleys have respective radii S Ir and S2r. Further, a ratio of the radius S Ir of the highest peak S 1 to the radius S2r of the lowest valley S2 is greater than about 2. In other words, S lr / S2r > 2. In some embodiments, the ratio S lr / S2r is greater than about 4, greater than about 6, greater than about 8, greater than about 10, greater than about 12, greater than about 15, or greater than about 20.

[0113] In the illustrated embodiment of FIG. 10, the first plot 80 of the radius r versus the location of the metallic elements 10 along the first row 25 includes the plurality of alternating peaks and valleys of the metallic elements 10 numbering at least 25 in total. Further, in the illustrated embodiment of FIG. 10, the radius Sir is about 1.15 mm and the radius S2r is about 0.08 mm, and the ratio Slr / S2r is about 13.88. Table 1 provided below includes the radii Sir and S2r and the ratio Slr / S2r for the illustrated embodiment of FIG. 10 in a tabular format.

[0114] Table 1

[0115] Where, r (x,0) represents the first row 25 of the metallic elements 10 in the tile 200c.

[0116] In some embodiments, a highest valley S3 in the plurality of alternating peaks and valleys has a radius S3r, such that a ratio of the radius S3r of the highest valley S3 to the radius S2r of the lowest valley S2 is greater than about 2. In other words, S3r / S2r > 2. In some embodiments, the ratio S3r / S2r is greater than about 4, greater than about 6, greater than about 8, greater than about 10, greater than about 15, or greater than about 20. In some embodiments, the ratio S3r / S2r is less than about 50. In some embodiments, the ratio S3r / S2r is less than about 40, less than about 30, less than about 20, less than about 15, or less than about 10. In the illustrated embodiment of FIG. 10, the radius S3r is about 0.77 mm and the ratio S3r / S2r is about 9.6.

[0117] In some embodiments, a lowest peak S4 in the plurality of alternating peaks and valleys has a radius S4r, such that a ratio of the radius S Ir of the highest peak S 1 to the radius S4r of the lowest peak S4 is greater than about 1.05. In other words, Slr / S4r > 1.05. In some embodiments, the ratio Slr / S4r is greater than about 1.1, greater than about 1.15, greater than about 1.2, greater than about 1.25, greater than about 5, or greater than about 10. In some embodiments, the ratio Slr / S4r is less than about 20. In some embodiments, the ratio Slr / S4r is less than about 15, less than about 10, less than about 5, or less than about 2. In the illustrated embodiment of FIG. 10, the radius S4r is about 0.91 mm and the ratio Slr / S4r is about 1.26.

[0118] The graph 700 further includes a second plot 81 of the radius r versus the location of the metallic elements 10 along the first column 27 shown in FIG. 6. The second plot 81 includes a global maximum QI and a global minimum Q2 having respective radii Qlr and Q2r, such that a ratio of the radius Qlr to the radius Q2r is greater than about 2, i.e., Qlr / Q2r > 2. In some embodiments, the ratio Qlr / Q2r is greater than about 4, greater than about 6, greater than about 8, greater than about 10, greater than about 12, greater than about 15, or greater than about 20. In the illustrated embodiment of FIG. 10, the radius Qlr corresponding to the global maximum QI is about 1.12 mm, the radius Q2r corresponding to the global minimum Q2 is about 0.08 mm, and the ratio Qlr / Q2r is about 13.52.

[0119] In some embodiments, the second plot 81 includes two substantially equally high global peaks QI, each of the high global peaks QI has the radius Qlr, and no other peaks between the two global peaks QI. In some embodiments, the second plot 81 does not include a global low valley. In some embodiments, the first column 27 includes a plurality of middle metallic elements 10 in the plurality of metallic elements 10 disposed between a pair of opposing end metallic elements 10 in the plurality of metallic elements 10. In some embodiments, at least one of the two end metallic elements 10 has the radius Q2r. In some embodiments, each of the two end metallic elements 10 has the radius Q2r.

[0120] Table 2 provided below includes the radii Qlr and Q2r and the ratio Qlr / Q2r for the illustrated embodiment of FIG. 10 in a tabular format.

[0121] Table 2

[0122] Where, r (0,y) represents the first column 27 of the metallic elements 10 on the tile 200c.

[0123] FIG. 11A shows a substantially collimated substantially planar radiofrequency (RF) electromagnetic wave 45 that has the free-space wavelength and propagates in an incident plane V2 that includes the first row 15 (shown in FIG. 4) and is incident at an incident angle e3 of between about 20 degrees to about 60 degrees on the reflective tile 200a shown in FIG. 4, according to an embodiment of the present disclosure.

[0124] For the substantially collimated substantially planar RF electromagnetic wave 45 and for the incident angle e3, the reflective tile 200a diffusely reflects at least a portion of the incident RF electromagnetic wave 45 as a diffusely reflected RF electromagnetic wave 45a at an angle e4. In the illustrated embodiment of FIG. 11 A, the incident angle e3 is about 45 degrees.

[0125] Therefore, the reflective tile 200a may be configured to scatter or redirect the substantially collimated substantially planar RF electromagnetic wave 45 having the free-space wavelength and incident at the incident angle e3, as per desired application attributes.

[0126] FIG. 11B shows a substantially collimated substantially planar substantially normally incident RF electromagnetic wave 44 that has the free-space wavelength and propagates in an incident plane V 1 that includes the first row 25 (shown in FIG. 6) and is incident on the reflective tile 200c shown in FIG. 6, according to an embodiment of the present disclosure.

[0127] The reflective tile 200c diffusely reflects at least a portion of the incident RF electromagnetic wave 44 as a diffusely reflected RF electromagnetic wave 44a, 44b at an angle el, e2. Specifically, the reflective tile 200c diffusely reflects at least a portion of the incident RF electromagnetic wave 44 as the diffusely reflected RF electromagnetic wave 44a at the angle el and diffusely reflects at least a portion of the incident RF electromagnetic wave 44 as the diffusely reflected RF electromagnetic wave 44b at the angle e2. Therefore, the reflective tile 200c may be configured to scatter or redirect the substantially collimated substantially planar substantially normally incident RF electromagnetic wave 44 having the free-space wavelength, as per desired application attributes.

[0128] FIG. 11C shows a graph 900 depicting reflection coefficient distributions of the reflective tiles 200a, 200c versus reflection angles, according to an embodiment of the present disclosure.

[0129] Reflected angle is expressed in degrees (deg) in the abscissa. The reflection coefficient is expressed in decibels (db) in the ordinate.

[0130] Referring to FIGS. 11A and 11C, the diffusely reflected RF electromagnetic wave 45a propagates in the incident plane V2 having a reflection coefficient distribution 45b in the incident planeV2 as a function of a reflection angle. The reflection coefficient distribution 45b has at least a first peak 45c propagating at a first reflection angle 45d of between about 5 degrees to about 70 degrees. In the illustrated embodiment of FIG. 11 A, the first reflection angle 45d is about 35 degrees.

[0131] In some embodiments, the reflection coefficient distribution 45b further has at least a second peak 45e propagating at a second reflection angle 45f greater than the first reflection angle 45d by at least 5 degrees. In some embodiments, the second reflection angle 45f is greater than the first reflection angle 45d by at least 10 degrees, at least 15 degrees, at least 20 degrees, at least 25 degrees, or at least 30 degrees. In the illustrated embodiment of FIG. 11A, the second reflection angle 45f is about 53 degrees and greater than the first reflection angle 45d by about 18 degrees.

[0132] Referring to FIGS. 11B and 11C, the diffusely reflected RF electromagnetic wave 44a, 44b propagates in the incident plane V 1 having a reflection coefficient distribution 44c in the incident plane VI as a function of a reflection angle. The reflection coefficient distribution 44c has at least a first peak 44d propagating at a first reflection angle 44e of between about 5 degrees to about 70 degrees. In the illustrated embodiment of FIG. 11C, the first reflection angle 44e is about 30 degrees.

[0133] In some embodiments, the reflection coefficient distribution 44c further has at least a second peak 44f propagating at a second reflection angle 44g greater than the first reflection angle 44e by at least 5 degrees. In some embodiments, the second reflection angle 44g is greater than the first reflection angle 44e by at least 10 degrees, at least 15 degrees, at least 20 degrees, at least 25 degrees, or at least 30 degrees. In the illustrated embodiment of FIG. 11C, the second reflection angle 44g is about 50 degrees and is greater than the first reflection angle 44e by about 30 degrees.

[0134] FIGS. 12A and 12B show schematic views of a tiled frequency selective reflective construction 300a, according to another embodiment of the present disclosure. Specifically, FIG. 12A shows a top view of the tiled frequency selective reflective construction 300a and FIG. 12B shows a side view of the tiled frequency selective reflective construction 300a.

[0135] The tiled frequency selective reflective construction 300a includes the plurality of reflective tiles 200c’ arranged at least in a row (i.e., substantially along the x-axis). The plurality of reflective tiles 200c’ may include the reflective tiles 200a, 200b, 200c, as disclosed herein. Referring to FIGS. 12A and 12B, the reflective tiles 200c’ includes the plurality of reflective tiles 200c’ arranged at least in the row so that when a substantially collimated incident RF electromagnetic wave 70 having the free-space wavelength is incident on the tiled frequency selective reflective construction 300a at an incident angle cl in a range from about zero degree to about 70 degrees, then each of the reflective tiles 200c’ diffusely reflects at least a portion of the incident RF electromagnetic wave 70 as a diffusely reflected RF electromagnetic wave 71a, 71b. The diffusely reflected RF electromagnetic wave 71a, 71b has a peak intensity 72a, 72b propagating along a reflected direction 73a, 73b at a reflection angle c2, c3.

[0136] For example, the diffusely reflected RF electromagnetic wave 71a has the peak intensity 72a propagating along the reflected direction 73a at the reflection angle c2, and the diffusely reflected RF electromagnetic wave 7 lb has the peak intensity 72b propagating along the reflected direction 73b at the reflection angle c3. The reflected direction 73a of at least a first one of the reflective tiles 200c’ is different from the reflected direction 73b of at least a second one of the reflective tiles 200c’. For example, in the illustrated embodiment of FIG. 12B, the reflected direction 73a of a first reflective tile 200c 1 of the reflective tiles 200c’ is different from the reflected direction 73b of a second reflective tile 200c2 of the reflective tiles 200c’.

[0137] In some embodiments, the reflected directions 73 a, 73b of the at least the first one of the reflective tiles 200c’ and the at least the second one of the reflective tiles 200c’ are substantially coplanar and are different by at least 10 degrees. In some embodiments, the reflected directions 73a, 73b are different by at least 20 degrees, by at least 30 degrees, by at least 40 degrees, by at least 50 degrees, by at least 60 degrees, or by at least 70 degrees. In some other embodiments, the reflected directions 73a, 73b of the at least the first one of the reflective tiles 200c’ and the at least the second one of the reflective tiles 200c’ are not coplanar.

[0138] Therefore, the tiled frequency selective reflective construction 300a including the plurality of reflective tiles 200c’ (e.g., the reflective tiles 200a, 200b, 200c) may be configured to scatter or redirect the substantially collimated incident RF electromagnetic wave 70 having the free-space wavelength, as per desired application attributes.

[0139] FIG. 13 shows a schematic view of a wireless system 1300, according to an embodiment of the present disclosure.

[0140] The wireless system 1300 includes spaced apart first transceiver 410 configured to at least emit an RF electromagnetic wave 420 having the free-space wavelength and a plurality of spaced apart second transceivers 411a, 411b. Each of the plurality of spaced apart second transceivers 411a, 411b is configured to at least receive an RF electromagnetic wave having the free-space wavelength. In some embodiments, the first transceiver 410 includes one or more of a signal transmitting tower, a mobile communication device, a repeater, and an antenna. In some embodiments, at least one of the second transceivers 411a, 411b includes one or more of a signal receiving tower, a mobile communication device, a repeater, and an antenna. The wireless system 1300 further includes the tiled frequency selective reflective construction 300 configured to receive the emitted RF electromagnetic wave 420 emitted by the first transceiver 410 and diffusely reflect at least a portion of the received RF electromagnetic wave 420. The tiled frequency selective reflective construction 300 diffusely reflects the portion of the received RF electromagnetic wave 420 as a diffusely reflected RF electromagnetic wave 421, so that a first portion 421a of the diffusely reflected RF electromagnetic wave 421 is received by one transceiver 411a of the second transceivers 411a, 411b and a second portion 421b of the diffusely reflected RF electromagnetic wave 421 is received by another transceiver 41 lb of the second transceivers 411a, 411b.

[0141] In some embodiments, the emitted RF electromagnetic wave 420 emitted by the first transceiver 410 makes a first angle bl with a normal 430 to the tiled frequency selective reflective construction 300. The first portion 421a of the diffusely reflected RF electromagnetic wave 421 received by the one transceiver 41 la of the second transceivers 41 la, 41 lb makes a second angle b2a with the normal 430, and the second portion 421b of the diffusely reflected RF electromagnetic wave 421 received by the one other transceiver 411b of the second transceivers 411a, 411b makes a third angle b2b with the normal 430. In some embodiments, the first, second, and third angles bl, b2a, b2b are different from each other by at least 5 degrees. In some embodiments, the first, second and third angles bl, b2a, b2b are different from each other by at least 10 degrees, at least 15 degrees, at least 20 degrees, at least 25 degrees, at least 30 degrees, at least 35 degrees, at least 40 degrees, or at least 45 degrees.

[0142] Referring to FIGS. 1-13, the tiled frequency selective reflective construction 300, 300a including the plurality of reflective tiles 200, 200c’ may be configured to diffusely scatter or diffusely reflect the emitted RF electromagnetic wave 420 emitted by the first transceiver 410, as per desired application attributes. This may provide a beam broadening functionality and a usage of the tiled frequency selective reflective constructions 300, 300a may provide a better RF coverage and may reduce RF attenuation issues.

[0143] Unless otherwise indicated, all numbers expressing feature sizes, amounts, and physical properties used in the specification and claims are to be understood as being modified by the term “about.” Accordingly, unless indicated to the contrary, the numerical parameters set forth in the foregoing specification and attached claims are approximations that can vary depending upon the desired properties sought to be obtained by those skilled in the art utilizing the teachings disclosed herein.

[0144] Although specific embodiments have been illustrated and described herein, it will be appreciated by those of ordinary skill in the art that a variety of alternate and / or equivalent implementations can be substituted for the specific embodiments shown and described without departing from the scope of the present disclosure. This application is intended to cover any adaptations or variations of the specific embodiments discussed herein. Therefore, it is intended that this disclosure be limited only by the claims and the equivalents thereof.

Claims

CLAIMS1. A tiled frequency selective reflective construction comprising a plurality of reflective tiles arranged along mutually orthogonal in-plane first and second directions, each of the reflective tiles comprising a plurality of spaced apart electrically isolated metallic elements forming mutually orthogonal rows and columns of the metallic elements, each of the metallic elements having an average in-plane outermost radius, such that for at least a first row of the metallic elements, a first plot of the radius versus a location of the metallic elements along the first row comprises a first global peak radius at a first location, a local peak radius at a second location, and a first global minimum radius at a third location between the first and second locations.

2. The tiled frequency selective reflective construction of claim 1, wherein at least one of the metallic elements of at least one of the tiles is an annulus.

3. The tiled frequency selective reflective construction of claim 1, wherein for a substantially normally incident light having a first visible wavelength in a visible wavelength range extending from about 420 nm to about 680 nm, each of the tiles has an optical transmittance of greater than about 10%.

4. The tiled frequency selective reflective construction of claim 1, wherein for a substantially collimated incident radiofrequency (RF) electromagnetic wave having a free-space wavelength in a range from about 1.0 mm to about 300 cm and for at least one incident angle in a range from about zero degree to about 70 degrees, each of the tiles has a specular reflectance of less than about 70% and a diffuse reflectance of greater than about 5%.

5. A wireless system comprising: spaced apart first transceiver configured to at least emit an RF electromagnetic wave having a free- space wavelength in a range from about 1.0 mm to about 300 cm, and a plurality of spaced apart second transceivers, each configured to at least receive an RF electromagnetic wave having the free-space wavelength; and the tiled frequency selective reflective construction of claim 1 configured to receive the emitted RF electromagnetic wave emitted by the first transceiver and diffusely reflect at least a portion of the received RF electromagnetic wave so that a first portion of the diffusely reflected RF electromagnetic wave is received by one of the second transceivers and a second portion of the diffusely reflected RF electromagnetic wave is received by one other of the second transceivers.

6. The wireless system of claim 5, wherein the emitted RF electromagnetic wave emitted by the first transceiver makes a first angle with a normal to the tiled frequency selective reflective construction, the first portion of the diffusely reflected RF electromagnetic wave received by the one of the second transceivers makes a second angle with the normal, and the second portion of the diffusely reflected RFelectromagnetic wave received by the one other of the second transceivers makes a third angle with the normal, wherein the first, second and third angles are different from each other by at least 5 degrees.

7. The tiled frequency selective reflective construction of claim 1, wherein for a substantially collimated substantially planar RF electromagnetic wave that has a free-space wavelength in a range from about 1.0 mm to about 300 cm and propagates in an incident plane that comprises the first row, and for an incident angle of between about 20 degrees to about 60 degrees, the reflective tile diffusely reflects at least a portion of the incident RF electromagnetic wave, the diffusely reflected RF electromagnetic wave propagates in the incident plane having a reflection coefficient distribution in the incident plane as a function of a reflection angle, the reflection coefficient distribution having at least a first peak propagating at a first reflection angle of between about 5 degrees to about 70 degrees.

8. A reflective tile for use in a tiled frequency selective reflective construction, the reflective tile comprising: a major surface comprising non-overlapping first through fourth surface portions, the first, second, and third surface portions defining, and being continuous without any surface opening, within closed respective first, second, and third outermost perimeters, the fourth surface portion defining, and being continuous without any surface opening between, continuous closed fourth outermost and innermost perimeters, the first outermost and the fourth innermost perimeters mutually coincident with each other, portions of the second outermost perimeter coincident with respective portions of the third and the fourth outermost perimeters so that the second surface portion completely isolates the third and fourth surface portions from each other; and a plurality of spaced apart electrically isolated metallic elements two-dimensionally arranged in, and numbering at least 10 in total in, each of the first through fourth surface portions, each of the metallic elements having a largest lateral dimension D, each of the metallic elements in the first and second surface portions having a greater largest lateral dimension than each of the metallic elements in the third and fourth surface portions.

9. The reflective tile of claim 8, wherein the first through fourth surface portions have respective total areas Al, A2, A3, and A4, and wherein A4 > A3 > Al > A2.

10. A reflective tile for use in a tiled frequency selective reflective construction, the reflective tile comprising a major surface comprising at least one continuous primary surface portion that has no surface openings, is disposed in an interior of the major surface, and has a continuous closed outer perimeter, the primary surface portion divided into a plurality of alternating first and second secondary surface portions numbering at least 3 in total, each of the first and second secondary surface portions being continuous without any surface opening and having a continuous closed outer perimeter that coincides with a portion of the closed outer perimeter of either an adjacent secondary surface portionor the primary surface portion, each of the first and second secondary surface portions comprising at least 10 spaced apart electrically isolated electrically conductive elements arranged two-dimensionally across the secondary surface portion, the electrically conductive elements having an average largest lateral dimension Dlavg in each of the first secondary surface portions and an average largest lateral dimension D2avg in each of the second secondary surface portion, Dlavg > D2avg.

Images