阅读说明：本技术 具有传输微波信号并反射红外线信号的金属层的窗 (Window with metal layer for transmitting microwave signal and reflecting infrared signal ) 是由 N·F·博雷利 A·M·布拉托科夫斯基 于 2020-04-08 设计创作，主要内容包括：窗结构包括传输微波信号并反射红外线信号的金属层。微波信号是频率在微波频率谱(也称作微波频谱)的信号。微波频谱从300兆赫(MHz)延续到300吉赫(GHz)。红外线信号是频率在红外线频率谱(也称作红外线频谱)的信号,红外线频谱从300GHz延续到430太赫(THz)。金属层可为不连续金属层,它是电气不连续金属层及/或物理不连续金属层。(The window structure includes a metal layer that transmits microwave signals and reflects infrared signals. A microwave signal is a signal having a frequency in the microwave frequency spectrum (also referred to as the microwave spectrum). The microwave spectrum extends from 300 megahertz (MHz) to 300 gigahertz (GHz). An infrared signal is a signal having a frequency in the infrared frequency spectrum (also referred to as the infrared spectrum) which extends from 300GHz to 430 terahertz (THz). The metal layer may be a discontinuous metal layer, which is an electrically discontinuous metal layer and/or a physically discontinuous metal layer.)

1. A window structure, comprising:

a glass substrate; and

a discontinuous metal layer configured to reflect infrared wavelengths, wherein the discontinuous metal layer comprises a metal island structure having a thickness and a lateral dimension and disposed adjacent to the glass substrate, wherein the thickness of the metal island structure is from 1 nanometer to 7 nanometers, wherein the lateral dimension of the metal island structure averages at least 15 nanometers.

2. The window structure of claim 1, wherein the discontinuous metal layer has a face coverage of 35% to 55%.

3. The window structure of claim 1 or 2, wherein the discontinuous metal layer provides a transmission of 0.4 to 1.0 for signals having a frequency of 6 gigahertz to 80 gigahertz and a reflection of 0.3 to 0.6 for signals having a frequency of 30 terahertz to 75 terahertz.

4. The window structure of any of claims 1-3, wherein the discontinuous metal layer comprises at least one of gold, silver, aluminum, or copper.

5. The window structure of any of claims 1-4, further comprising:

a dielectric layer comprising Si₃N₄SnO, WO or LaB₆At least one of (a);

wherein the discontinuous metal layer is between the dielectric layer and the glass layer.

6. The window structure of any of claims 1-5, further comprising:

an anti-reflective layer between the glass substrate and the discontinuous metal layer, the anti-reflective layer comprising TiO₂SnO, WO or LaB₆At least one of (1).

7. A window structure, comprising:

a glass layer; and

a metal layer formed on the glass layer, the metal layer configured to transmit signals at a frequency of 28 gigahertz to 60 gigahertz and further configured to reflect signals having an infrared frequency.

8. The window structure of claim 7, wherein the metal layer is configured to transmit signals at a frequency of 6 gigahertz to 80 gigahertz.

9. The window structure of claim 7 or 8 wherein the metal layer has a resistance of at least 10 megaohms to signals having a frequency of 28 gigahertz to 60 gigahertz.

10. The window structure of any of claims 7-9, wherein the metal layer has a resistance of at least 100 megaohms for signals having frequencies of 28 gigahertz to 60 gigahertz.

11. The window structure of any of claims 7-10, wherein the metal layer is configured to reflect at least 20% of signals having infrared frequencies.

12. The window structure of any of claims 7-11, wherein the metal layer has a value of less than or equal to 10 for signals having a frequency of 28 gigahertz to 60 gigahertz^-5Siemens/meter conductivity.

13. The window structure of any of claims 7-12, wherein the metal layer provides at least 80% transmission in the frequency range of 28 gigahertz to 60 gigahertz.

14. The window structure of any of claims 7-13, wherein the metal layer provides at least 80% transmission in the frequency range of 6 gigahertz to 80 gigahertz.

15. The window structure of any of claims 7-14, wherein the metal layer is an electrically discontinuous metal layer.

16. The window structure of claim 15, wherein the electrically discontinuous metal layer has a face coverage of 35% to 55%.

17. A method of manufacturing a window structure, the method comprising:

providing a glass layer; and

forming a metal layer onto the glass layer, the forming the metal layer comprising:

the metal layer is configured to transmit signals at frequencies of 28 gigahertz to 60 gigahertz and reflect signals having infrared frequencies.

18. The method of claim 17, wherein forming the metal layer comprises:

the metal layer is configured to have a resistance of at least 10 megaohms to a signal having a frequency of 28 gigahertz to 60 gigahertz.

19. The method of claim 17 or 18, wherein forming the metal layer comprises:

the metal layer is configured to reflect at least 30% of signals having infrared frequencies.

20. The method of any of claims 17 to 19, wherein forming the metal layer comprises:

the metal layer is configured to have a frequency of less than or equal to 10 gigahertz for signals having a frequency of 28 gigahertz to 60 gigahertz^-5Siemens/meter conductivity.

21. The method of any of claims 17-20, wherein forming the metal layer comprises:

the metal layer is configured to provide at least 80% transmission over a frequency range of 28 gigahertz to 60 gigahertz.

22. The method of any of claims 17-21, wherein forming the metal layer comprises:

the metal layer is configured as an electrically discontinuous metal layer.

23. The method of claim 22, wherein configuring the metal layer comprises:

the electrically discontinuous metal layer is configured to have a face coverage of 35% to 55%.

24. The method of claim 22 or 23, further comprising:

removing a portion of the metal layer in response to forming the metal layer on the glass layer;

wherein removing a portion of the metal layer causes the metal layer to become electrically discontinuous.

25. A method of using a window structure having a glass layer and a metal layer formed on the glass layer, the method comprising:

receiving an infrared signal having an infrared frequency at the metal layer;

receiving a microwave signal at the metal layer at a frequency of 28 gigahertz to 60 gigahertz;

transmitting the microwave signal through the metal layer based at least in part on the configuration of the metal layer; and

the infrared signal is reflected from the metal layer based at least in part on the configuration of the metal layer.

26. The method of claim 25, wherein transmitting the microwave signal comprises:

based at least in part on the metal layer, and the metal layer is an electrically discontinuous metal layer through which the microwave signal is transmitted.

Technical Field

The present invention relates generally to window structure embodiments and related method of making and using embodiments, wherein the window structure is configured to transmit microwave signals and reflect (e.g., exclude) infrared signals. More particularly, the present invention relates to window structures that include a glass layer and a metal layer formed on the glass layer such that the metal layer is configured to transmit signals having frequencies of 28 gigahertz to 60 gigahertz and is further configured to reflect signals having infrared frequencies.

Background

Recent window design innovations have made windows more energy efficient. The window may have a single pane (e.g., a window pane) or multiple panes of glass. Each sheet may comprise a single layer of glass or multiple layers of glass attached with an adhesive. The energy efficiency of modern windows is typically improved by covering the surface of at least one sheet with a low thermal emissivity coating (also referred to as a low E coating) and/or filling the inter-sheet spaces with an inert gas having a relatively low thermal conductivity. Each low-E coating manages Electromagnetic (EM) radiation incident to the coating.

The low E coating is typically a metal. For example, silver is often used as a low E coating. Accordingly, low E coatings generally reflect frequencies used for cellular communications in addition to blocking infrared frequencies for improved energy efficiency. The low E coating can attenuate microwaves having frequencies greater than 1.0 gigahertz (GHz) by up to 40 decibels (dB). Building materials typically allow frequencies 0.6GHz to 2.7GHz to pass through and attenuation is relatively low for 3G and 4G cellular systems. So 3G and 4G frequencies are not traditionally much attenuated by the low E coating of the window. However, the same building materials typically attenuate the frequency range of 6GHz to 100GHz considerably (e.g., approaching 100% in some cases). Therefore, as the 5G system has grown, the reflection of microwave frequencies by conventional windows with low E coatings has become a more pressing issue.

SUMMARY

Various window structures are described herein that are configured to include a metal layer that transmits microwave signals and reflects (e.g., excludes) infrared signals. A microwave signal is a signal having a frequency in the microwave frequency spectrum (also referred to as the microwave spectrum). The microwave spectrum extends from 300 megahertz (MHz) to 300 GHz. An infrared signal is a signal having a frequency in the infrared frequency spectrum (also referred to as the infrared spectrum). The infrared spectrum extends from 300GHz to 430 terahertz (THz). The metal layer may or may not be a discontinuous metal layer. The discontinuous metal layer is a metal layer that is an electrically discontinuous metal layer and/or a physically discontinuous metal layer. Therefore, the discontinuous metal layer has extremely low Direct Current (DC) conductivity.

A physically discontinuous metal layer is a metal layer that includes a plurality of metal portions that are arranged in a plane such that, in the plane, the metal portions do not form a continuous path of metal between opposing sides of the metal layer. For example, in-plane, the metal portion does not form a continuous metal path between any two opposing sides of the metal layer. In another example, any one or more (e.g., all) of the metal portions do not directly physically contact any other metal portion. A metal portion that does not directly physically contact any other metal portion is defined herein as a metal island structure. For example, the metal island structures may be separated from other metal portions by a non-metallic substance, such as a gas (e.g., air, noble gas, hydrogen, or nitrogen).

An electrically discontinuous metal layer is a metal layer in which one or more edge boundaries inhibit the flow of electrons from a first side of the metal layer to a second, opposite side of the metal layer for at least part of the microwave spectrum. In one example, the metal layer includes metal island structures, and each metal island structure is electrically isolated from other metal island structures of the metal layer. According to this example, the gaps between the metal island structures form boundaries to inhibit electrons from flowing to adjacent metal island structures. Also according to this example, each metal island structure may be conductive; however, the DC conductivity of the metal layer as a whole is substantially less than that of a single metal island structure, since the metal island structure is electrically isolated from other metal island structures. In another example, the chemical composition of the metal layer may cause the metal layer to become electrically discontinuous.

A first exemplary window structure includes a glass layer and a metal layer. The metal layer is formed on the glass layer. The metal layer is configured to transmit signals having a frequency of 28 gigahertz to 60 gigahertz and is further configured to reflect signals having an infrared frequency.

A second exemplary window structure includes a glass substrate and a discontinuous metal layer. The discontinuous metal layer is configured to reflect infrared wavelengths. The discontinuous metal layer comprises a metal island structure having a thickness and lateral dimensions and disposed adjacent to the glass substrate. The thickness of the metal island structure is 1 to 7 nanometers. The lateral dimension of the metal island structures is on average at least 15 nanometers.

In an exemplary method of manufacturing a window structure, a glass layer is provided. The metal layer is formed on the glass layer. Forming the metal layer includes configuring the metal layer to transmit signals at frequencies of 28 gigahertz to 60 gigahertz and to reflect signals having infrared frequencies.

In an exemplary method of using a window structure, the window structure has a glass layer and a metal layer formed on the glass layer, and an infrared signal having an infrared frequency is received in the metal layer. A microwave signal having a frequency of 28 gigahertz to 60 gigahertz is received in the metal layer. Transmitting a microwave signal through the metal layer based at least in part on the configuration of the metal layer. The infrared signal is reflected from the metal layer based at least in part on the configuration of the metal layer.

This "overview" is provided to briefly summarize the concept that is refined, which will be further detailed in the embodiments below. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter. Furthermore, it should be noted that the present invention is not limited to the specific implementations described in the detailed description and/or other sections herein. The embodiments presented herein are for illustration purposes only. Additional embodiments will be apparent to persons skilled in the relevant art(s) based on the teachings contained herein.

Brief description of the drawings

The accompanying drawings, which are incorporated herein and form a part of the specification, illustrate embodiments of the present invention and, together with the description, further serve to explain the principles involved and to enable a person skilled in the pertinent art to make and use the techniques.

Fig. 1 is a cross-section of an exemplary window structure having a microwave transmitting (mw transmitting) infrared reflecting (IR reflecting) metal layer, according to one or more embodiments of the present invention.

Fig. 2 illustrates exemplary elemental concentrations versus etch time that may be used to fabricate a window structure in accordance with one or more embodiments of the invention.

FIG. 3 is a graph of the mw transmissive IR reflective metal layer shown in FIG. 1, including exemplary plots of transmittance versus reflectance versus wavelength, in accordance with one or more embodiments of the present invention.

FIG. 4 is a graph of three different black bodies with respective temperatures, including exemplary plots of spectral intensity versus wavelength, in accordance with one or more embodiments of the present invention.

Fig. 5 is a graph of microwave signals through various structures, including exemplary plots of loss versus frequency, in accordance with one or more embodiments of the present invention.

Fig. 6 is a graph of a low-E coated window without a low-E coating and a metal film low-E coated window, including exemplary plots of transmission loss versus frequency, according to one or more embodiments of the invention.

FIG. 7 is a schematic view of a metal film with grain boundary scattering according to one or more embodiments of the present invention.

Fig. 8 is a schematic illustration of a metal film with surface roughness scattering according to one or more embodiments of the invention.

Fig. 9 is an exemplary plot of resistivity versus thickness for an unannealed metal film, in accordance with one or more embodiments of the present invention.

Fig. 10 is an exemplary plot of resistivity versus thickness for an annealed metal film, according to one or more embodiments of the invention.

Fig. 11 illustrates exemplary plots of transmittance, reflectance, and absorbance versus frequency for silver films having thicknesses of 30nm and 5nm, respectively, in accordance with one or more embodiments of the present invention.

Fig. 12A illustrates the behavior of a window structure with a mw transmitting IR reflecting metal layer, according to one or more embodiments of the invention.

Fig. 12B illustrates the behavior of a window structure with a low E metal film, according to one or more embodiments of the invention.

Fig. 13 illustrates exemplary plots of transmittance, reflectance, and absorptance of a discontinuous metal layer versus metal fill fraction, according to one or more embodiments of the invention.

Fig. 14A-14C are exemplary SEM images of discontinuous gold layers having thicknesses of 4nm, 7nm, and 10nm, respectively, in accordance with one or more embodiments of the present invention.

Fig. 15 is an exemplary plot of electrostatic conductivity versus fractional fill of a metal surface for a discontinuous layer of gold, according to one or more embodiments of the invention.

Fig. 16 illustrates a graph of conductivity versus frequency for a gold film and a gold layer including gold island structures, in accordance with one or more embodiments of the invention.

FIG. 17 illustrates a graph of the transmission and reflection of a discontinuous metal layer versus the fractional fill of the metal surface for a 10GHz microwave frequency and a 2.5 micrometer (μm) near infrared wavelength, in accordance with one or more embodiments of the invention.

Fig. 18 illustrates exemplary process steps for fabricating a window having a discontinuous metal layer, in accordance with one or more embodiments of the present invention.

Fig. 19 illustrates an exemplary method flow diagram for manufacturing a window structure, according to one or more embodiments of the invention.

Fig. 20 illustrates an exemplary method flow diagram for using a window structure having a glass layer and a metal layer formed on the glass layer, according to one or more embodiments of the invention.

The features and advantages of the described techniques will become more readily apparent upon consideration of the following detailed description and accompanying drawings, in which like reference numerals identify corresponding components. Like reference symbols in the various drawings indicate substantially the same, functionally similar, and/or structurally similar elements. The drawing in which a component first appears is indicated by the leftmost digit(s) in the corresponding component symbol.

Detailed Description

I. Preamble of preamble

The following detailed description describes exemplary embodiments of the invention with reference to the accompanying drawings. The scope of the invention is not, however, limited to these embodiments, but is defined by the appended claims. Therefore, embodiments not shown in the drawings are still covered by the present invention, such as modifications of the illustrated embodiments.

References in the specification to "an embodiment," "one embodiment," "an example embodiment," etc., indicate that the embodiment described may include a particular feature, structure, or characteristic, but every embodiment may not necessarily include the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is submitted that it is within the knowledge of one skilled in the relevant art to effect such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described.

Words such as "first," "second," "third," etc. are used to refer to some of the components. Such phrases are used to facilitate discussion of the exemplary embodiments and are not intended to indicate a required order to the components unless such order is explicitly indicated herein as being required.

Exemplary embodiments

The exemplary window structure is configured to include a metal layer that transmits microwave signals and reflects (e.g., excludes) infrared signals. A microwave signal is a signal having a frequency in the microwave frequency spectrum (also referred to as the microwave spectrum). The microwave spectrum extends from 300 megahertz (MHz) to 300 GHz. An infrared signal is a signal having a frequency in the infrared frequency spectrum (also referred to as the infrared spectrum). The infrared spectrum extends from 300GHz to 430 terahertz (THz). The metal layer may or may not be a discontinuous metal layer. The discontinuous metal layer is a metal layer that is an electrically discontinuous metal layer and/or a physically discontinuous metal layer.

A physically discontinuous metal layer is a metal layer that includes a plurality of metal portions that are arranged in a plane such that, in the plane, the metal portions do not form a continuous path of metal between opposing sides of the metal layer. For example, in-plane, the metal portion does not form a continuous metal path between any two opposing sides of the metal layer. In another example, any one or more (e.g., all) of the metal portions do not directly physically contact any other metal portion. A metal portion that does not directly physically contact any other metal portion is defined herein as a metal island structure. For example, the metal island structures may be separated from other metal portions by a non-metallic substance, such as a gas (e.g., air, noble gas, hydrogen, or nitrogen).

An electrically discontinuous metal layer is a metal layer in which one or more edge boundaries inhibit the flow of electrons from a first side of the metal layer to a second, opposite side of the metal layer for at least part of the microwave spectrum. In one example, the metal layer includes metal island structures, and each metal island structure is electrically isolated from other metal island structures of the metal layer. According to this example, the gaps between the metal island structures form boundaries to inhibit electrons from flowing to adjacent metal island structures. Also according to this example, each metal island structure may be conductive; however, the conductivity of the metal layer as a whole is substantially less than that of a single metal island structure, since the metal island structure is electrically isolated from other metal island structures. In another example, the chemical composition of the metal layer may cause the metal layer to become electrically discontinuous.

The exemplary window structure has several advantages over conventional window structures. For example, exemplary window structures may provide higher energy efficiency (e.g., by attenuating infrared frequencies) while transmitting one or more microwave frequencies (e.g., 5G frequencies). For example, microwave frequencies may include 28GHz, 37GHz, 39GHz, and/or 60 GHz. Thus, the 5G device can communicate with the base station (and vice versa) via the exemplary window structure.

The exemplary window structure may be fabricated using conventional fabrication techniques, plus additional steps (e.g., an annealing process to form metal island structures in the metal layer). The window structure is fully compatible with existing 4G (e.g., < 2.7GHz frequency) and developed 5G (e.g., 28GHz, 37GHz, 39GHz, 60GHz) frequency standards. The frequency response of the exemplary window structure is flat up to at least 10 THz. Conventional antireflective layers and barrier layers work substantially the same on metal layers comprising metal island structures as on continuous metal films, since the metal island structures can be flat and have widths of tens of nanometers, which are substantially smaller than the wavelength of light.

Fig. 1 is a cross-section of an exemplary window structure 100 having a microwave transmitting (mw transmitting) infrared reflecting (IR reflecting) metal layer 110, according to an embodiment. As shown in fig. 1, the window structure 100 includes the following layers in order: a glass substrate 102, a bottom layer 104, a first dielectric layer 106, a first barrier layer 108, an mw-transmissive IR-reflective metal layer 110, a second barrier layer 112, a second dielectric layer 114, and a cap layer 116.

The glass substrate 102 is a glass layer on which the other layers of the window structure 100 are formed. The glass layer can be a glass material, such as Soda Lime Glass (SLG), Eagle XG (EXG)^TM) Glass or High Purity Fused Silicon^TM(HPFS^TM) And (3) glass. Note that the loss tangent of SLG is about EXG^TMTen times the loss tangent of the glass (e.g., at 5G frequencies, such as 28GHz, 37GHz, 39GHz, and/or 60 GHz). EXG^TMThe loss tangent of the glass is about HPFS^TMTen times the loss tangent of the glass (e.g., at 5G frequencies, such as 28GHz, 37GHz, 39GHz, and/or 60 GHz). EXG^TMGlass and HPFS^TMGlass is manufactured and sold by Corning corporation.

The bottom layer 104 and the cap layer 116 comprise a moisture resistant oxide. Thus, the bottom layer 104 and the cap layer 116 may inhibit moisture from reaching (e.g., penetrating) the mw-transmissive IR-reflective metal layer 110. The bottom layer 104 may increase adhesion between the substrate 102 and the first dielectric layer 106 and/or increase the transmission of visible light through the mw transmissive IR reflective metal layer 110. The bottom layer 104 may include a metal nitride, a metal oxide, and/or a metal oxynitride. The capping layer 116 may improve the scratch resistance of the window structure 100. The first dielectric layer 106 comprises an oxide that electrically insulates the mw-transmissive IR-reflective metal layer 110 from the bottom layer 104. The second dielectric layer 114 comprises an oxide that electrically insulates the mw-transmissive IR-reflective metal layer 110 from the cap layer 116. The first and second dielectric layers 106, 114 may each comprise Si₃N₄、SnO、SnO₂、ZnO:Al、WO、LaB₆And/or other dielectric materials. The first and second barrier layers 108, 112 each include an anti-reflective material and are configured to mitigate reflection of visible light from the window structure 100. Each of the first and second barrier layers 108, 112 may comprise TiO₂、SnO、WO、LaB₆And/or other anti-reflective materials.

mw transmitting IR reflecting metal layer 110 is configured to transmit microwave signals and reflect infrared signals. For example, mw transmitting IR reflecting metal layer 110 may be configured to transmit signals having frequencies in one or more portions of the microwave spectrum. For example, the mw transmissive IR reflective metal layer 110 may be configured to transmit signals at frequencies of 6GHz to 80GHz, 28GHz to 60GHz, and/or other ranges in the microwave spectrum.

In another example, the mw transmitting IR reflecting metal layer 100 may provide a transmittance greater than or equal to the critical transmittance in one or more portions of the microwave spectrum. For example, the critical transmission may be 40%, 50%, 60%, 70%, 80%, or 90%. The transmittance of the mw-transmissive IR reflective metal layer 100 in the frequency range of 28GHz to 60GHz, the frequency range of 6GHz to 80GHz, and/or other ranges of the microwave spectrum may be greater than or equal to the critical transmittance. For example, the transmittance of the mw transmissive IR reflective metal layer 100 may be as high as 100% in one or more ranges of the microwave spectrum.

In yet another example, the mw-transmissive IR reflective metal layer 100 may provide 35% to 100%, 40% to 100%, 50% to 100%, or 60% to 100% transmission in one or more portions of the microwave spectrum. For example, the mw transmissive IR reflective metal layer 100 may provide the above-described transmissivity for signals at frequencies 28GHz to 60GHz, 6GHz to 80GHz, and/or other ranges in the microwave spectrum.

In yet another example, the mw transmitting IR reflecting metal layer 100 may have a resistance to signals having a frequency in one or more portions of the microwave spectrum that is greater than or equal to the critical resistance. For example, the critical resistance may be 5 megaohms (M Ω), 10M Ω, 20M Ω, 50M Ω, 100M Ω, or 200M Ω. The resistance of the mw transmissive IR reflective metal layer 100 to signals having frequencies from 6GHz to 80GHz, 28GHz to 60GHz, and/or other ranges in the microwave spectrum may be greater than or equal to the critical resistance.

In another example, the mw transmitting IR reflecting metal layer 100 may have a conductivity less than or equal to a critical conductivity for signals having frequencies in one or more portions of the microwave spectrum. For example, the critical conductivity may be 10^-4Siemens/m (S/m), 10^-5S/m or 10^-6And (5) S/m. The conductivity of the mw transmitting IR reflecting metal layer 100 may be less than or equal to that of signals having frequencies of 6GHz to 80GHz, 28GHz to 60GHz, and/or other ranges in the microwave spectrumAt a critical conductivity.

In yet another example, the mw transmitting IR reflecting metal layer 100 may be configured to reflect at least a critical proportion of the infrared signal. For example, the critical proportion may be 15%, 20%, 25%, 30% or 40%.

In yet another example, the mw transmitting IR reflecting metal layer 100 may provide 20% to 70%, 25% to 65%, 30% to 60%, or 35% to 55% reflectivity in one or more portions of the infrared spectrum. For example, the mw transmitting IR reflective metal layer 100 may provide the above-described reflectivity for signals at frequencies 25THz to 80THz, 30THz to 75THz, 35THz to 70THz, or 40THz to 65 THz.

In another example, the metal layer may be a discontinuous metal layer. For example, the metal layer may be an electrically discontinuous metal layer and/or a physically discontinuous metal layer. In one aspect of this example, the discontinuous metal layer comprises a planar arrangement of metal island structures. The metal islands may have any shape and/or size, however, the scope of the example embodiments is not limited in this respect. The planar layer projected area is the planar area defined by the projection of the discontinuous metal layer onto the plane. The island projected area of the plane is the area of the plane defined by the projection of each metal island structure onto the plane. The surface coverage of the discontinuous metal layer is defined as the island projected area divided by the layer projected area. The area coverage may be greater than or equal to a lower threshold. For example, the lower threshold may be 25%, 30%, 35%, 40%, or 45%. The area coverage may be less than or equal to the upper threshold. For example, the upper threshold may be 45%, 50%, 55%, 60%, or 65%. The area coverage may be between a lower threshold and an upper threshold.

The mw transmitting IR reflecting metal layer 110 may comprise any suitable metal, including but not limited to gold, silver, aluminum, copper, or any combination thereof.

The mw transmitting IR reflecting metal layer 110 shown in fig. 1 has a thickness T. Thus, if the mw-transmissive IR-reflective metal layer 110 includes metal islands, the metal islands have a thickness T. The thickness T may be greater than or equal to a lower thickness threshold. For example, the lower thickness threshold may be 0.5 nanometers (nm), 1nm, 1.5nm, 2nm, or 3 nm. The thickness T may be less than or equal to an upper thickness threshold. For example, the upper threshold of thickness may be 5nm, 6nm, 7nm, 8nm, or 10 nm. The thickness T may be between a lower thickness threshold and an upper thickness threshold. If the mw transmissive IR reflective metal layer 110 includes metal islands, each metal island may have a lateral dimension that is perpendicular to the axis of the measured thickness T. For example, the metal islands can be configured such that the average lateral dimension of the metal islands is greater than or equal to a critical dimension. For example, the critical dimension may be 10nm, 12nm, 15nm, 20nm, or 25 nm. For example, metal islands having a lateral or average lateral dimension greater than or equal to 20nm may reduce absorption of microwave signals by mw transmitting IR reflecting metal layer 110. Each metal island may be configured to have a lateral dimension substantially greater than the thickness T of the metal island.

The exemplary layers shown in FIG. 1 are for illustration only and are not intended to be limiting. The window structure 100 may not include one or more of the layers shown in fig. 1. Further, the window structure 100 may include layers in addition to or in place of one or more of the layers shown in FIG. 1.

Fig. 2 illustrates exemplary elemental concentrations versus etch time, which may be used to fabricate a window structure (e.g., window structure 100 shown in fig. 1), in accordance with an embodiment.

FIG. 3 is a graph 300 of the mw transmissive IR reflective metal layer 110 shown in FIG. 1, including exemplary plots 302, 304 of transmittance and reflectance, respectively, versus wavelength. With respect to graph 302, transmittance is shown along the right Y-axis of graph 300 and wavelength is shown along the X-axis of graph 300. As for plot 304, reflectance is shown along the left Y-axis of plot 300 and wavelength is shown along the X-axis of plot 300.

In the wavelength range shown in fig. 3, the low E window functions as a bandpass filter in which the peak transmission is about 90% for wavelengths in the visible spectrum 306 while substantially reflecting wavelengths in the infrared spectrum. Visible spectrum 306 includes wavelengths of about 390 nanometers (nm) to 700 nm. The infrared spectrum includes wavelengths of 700nm to 1 millimeter (mm). The wavelengths of the infrared spectrum are referred to as "infrared wavelengths". The exemplary embodiment enables the low E window to function as a bandpass filter including a plurality of passbands. For example, the band pass filter may include a pass band having the visible spectrum and one or more additional pass bands having portions of the microwave spectrum while still substantially reflecting infrared wavelengths. The microwave spectrum includes wavelengths from 1mm to 1 meter (m). The wavelength of the microwave spectrum is referred to as the "microwave wavelength".

FIG. 4 is a graph 400 of three different black bodies, each with temperature, including exemplary plots 402, 404, 406 of spectral intensity versus wavelength. Plot 402 corresponds to a black body (e.g., the sun) at 6000K. Graph line 404 corresponds to a black body with a temperature of 3000K. The graph 406 corresponds to a black body (e.g., a room within a building) having a temperature of 300K. In a 300K blackbody, radiation starts at a wavelength of about 4 microns (μm) and peaks at a wavelength of about 10 μm. The exemplary embodiment is capable of reflecting radiation associated with plot 406 while allowing transmission of radiation in the microwave spectrum. For example, the window structure may reflect radiation associated with plot 406 back into the room while allowing radiation in the microwave spectrum to be transmitted into and/or out of the room through the window structure.

Fig. 5 is a graph 500 of microwave signals through various structures, including exemplary plots 502, 504, 506, 512, 514, 516 of loss versus frequency. Plots 502, 512 depict the computer simulated loss and measured loss, respectively, of the microwave signal through the wall. Plots 504, 514 depict the computer simulated loss and measured loss, respectively, of a microwave signal through a low E glass, including a metal film. Plots 506, 516 depict the computer simulated loss and measured loss, respectively, of the microwave signal through standard glass (i.e., glass that does not include a low-E coating). The losses were simulated and measured in the frequency range of 0.8GHz to 40 GHz.

As shown by plots 504, 514, 4G signals (e.g., 2.7GHz signals) are blocked by the low E glass with a 26dB loss; however, as shown by the graphs 502, 512, the 4G signal passes through the wall unimpeded. As further shown by plots 504, 514, 5G signals (e.g., 28-40GHz signals) are blocked by the low E glass with losses of 26-37 dB; also as shown by the graphs 502, 512, the 5G signal is substantially completely blocked by the walls (e.g., about 100dB loss). The blocking behavior of low E glasses appears to be due to the metal film contained therein blocking the microwave transmission. For example, the transmittance may be simply calculated as follows:

tx 1/(1+ Z0/(2Rs)) formula 1

Wherein Rs 1/(σ d) [ Ω/sq ] is the resistance per unit square of the metal film; σ is the conductivity of the metal film; d is the thickness of the metal film; z0/2 is half the free space impedance at 188 Ω. In some industrial standard metal films for low E windows, Rs ═ 2-5[ Ω/sq ], so Tx ≈ 2Rs/Z0 < 1, the response is flat in the microwave spectrum covering 4G, 5G and up to the THz region.

By replacing the metal film of the low-E glass with an mw transmitting IR reflecting metal layer (e.g., mw transmitting IR reflecting metal layer 110), the loss of the microwave signal through the low-E glass can be reduced. Thus, as indicated by arrow 518, the use of mw transmissive IR reflective metal layer for low E glass will shift plots 504, 514 toward plots 506, 516, which correspond to standard glass.

Fig. 6 is a graph 600 of a window without a low E coating and a window with a metal film low E coating, including exemplary plots 602, 604 of transmission loss versus frequency. In the embodiment shown in FIG. 6, for non-limiting illustration purposes, a window having a metal film low E coating includes three layers of metal film low E coating on glass having a thickness of 30 nm. As shown in fig. 6, the loss is essentially negligible compared to the window without the low E coating, and the window with the metal film low E coating provides a fairly flat 20dB transmission loss for 25GHz to 45 GHz.

The use of an mw transmitting IR reflecting metal layer (e.g., mw transmitting IR reflecting metal layer 110) in place of a metal film low E coating in the window reduces transmission losses of the microwave signal through the window. Thus, as indicated by arrow 606, the window transmitting the IR reflective metal layer with mw will shift plot 604 to plot 602, which corresponds to the window without the low E coating.

Electron scattering substantially contributes to higher transmission losses for microwave frequencies for conventional metal film low E coatings. For example, electron scattering helps to shorten the effective mean free path of electrons through the metal film and defines the response of the metal film to microwaves and light. Electron scattering in thin films (e.g., metal film low E coatings) can be caused by grain boundary scattering and/or surface roughness scattering. The exemplary window structure may mitigate the effects of grain boundary scattering and/or surface roughness scattering.

Fig. 7 is a schematic view of a metal film 700 in which grain boundary scattering occurs. As shown in fig. 7, the metal film 700 includes a plurality of grains. The grains include a first grain 702, a second grain 704, a third grain 706, and a fourth grain 708. The first electrons 716 in the first die 702 are scattered from the first surface 710 between the first die 702 and the second die 704. The first electron 716 is then scattered from the second surface 712 of the outer boundary of the metal film 700. A second electron 718 in the third die 706 scatters from the third surface 714 between the third die 706 and the fourth die 708. Scattering of the first electron 716 from the first surface 710 and the second surface 712 inhibits the transmission of the first electron 716 through the metal film 700. Scattering of the second electron 718 from the third surface 714 inhibits the second electron 718 from transmitting through the metal film 700.

The grains in the metal film 700 may have any suitable size and vary by any suitable amount. For example, if the metal film 700 is 50nm thick, the grain size may vary by 19 nm. If the metal film 700 is 20nm thick, the grain size may vary by 10.8 nm. If the metal film 700 is 12nm thick, the crystal grain size may vary by 8.4nm, etc. The exemplary thicknesses and variations are for non-limiting illustration only.

The exemplary embodiments can reduce grain boundary scattering encountered by electrons in the metal layer. For example, the metal layer may be a physically discontinuous metal layer comprising metal islands. According to this example, each metal island may have fewer grains than the entire metal layer, facilitating electron transport through the metal island. Also according to this example, electrons may travel between the metal islands to facilitate transport through the metal layer.

Fig. 8 is a schematic diagram of a metal film 800 in which surface roughness scattering occurs. The surface roughness scattering in the metal film 800 can be simulated using, for example, the "Fabry-Perot Mulberry (Fuchs-Sondheimer) model". According to the Fanqi-Mulumo model, electrons have a limited mean free path due to phonon and impurity scattering. Again according to this model, the specular reflection coefficient p can be used to determine the fraction of electrons that are scattered at the surface 806 of the metal film 800. The first electron 802 and the second electron 804 are shown incident on the surface 806 of the metal film 800 to illustrate the difference in the amount of scattering, as indicated by the values of the specular reflectance. In a first example, a specular reflectance value of 1 (i.e., p ═ 1) will result in all (i.e., 100%) of the first electrons 802 being scattered at the surface 806. In a second example, when the specular reflectance value is zero (i.e., p-0), none (i.e., 0%) of the second electrons 804 are scattered at the surface 806.

The exemplary embodiments can reduce surface roughness scattering encountered by electrons in the metal layer. For example, in a physically discontinuous metal layer, electrons may travel between metal islands therein to reduce some electrons from encountering surface roughness scattering in the metal layer.

The resistivity of the metal film varies depending on the thickness of the metal film. Fig. 9 is an exemplary plot 900 of resistivity versus thickness for an unannealed metal film. Graph 900 illustrates exemplary effects of various scattering mechanisms on the resistivity of unannealed metal films. The effects include volume resistivity effects 902 and grain boundary scattering effects 904.

Fig. 10 is an exemplary plot 1000 of resistivity versus thickness for an annealed metal film. Graph 1000 illustrates exemplary effects of various scattering mechanisms on the resistivity of an annealed metal film. The effects include volume resistivity effects 1002, grain boundary scattering effects 1004, and interface scattering effects 1006.

The resistivity dependence of the metal film can be defined by the following formula:

ρ/ρ_{volume of}＝1+0.375(1-p)S*l/d+[1.5R/(1-R)]L/g formula 2

Where ρ is_{Volume of}Is the resistivity of the bulk metal; p is Faqu-Mulumo specular reflection factor (p ═ 0); s is a surface roughness factor, which is in the range of 1 to 2; r is the reflectance of the grain boundary, which is in the range of 0.07 to 0.10; l is the volume mean free path; g is the grain size. See S.M.Rosssnagel and T.S.Kuan, "Alteration of Cu reduction in the size effect region", J.Vac.Sci.Techniol.B 22(1), p.240-. Note that the product of the resistivity ρ and the scattering time τ of the metal film is constant (i.e., ρ τ is constant). For example, with silver, ρ τ is 59 ± 2 μ Ω · cm. The scattering time defines the frequency dependence of the dielectric function of the film by the simple Drude (Drude) formula, which applies to microwave and optical frequencies:

ε(ω)＝ε_∞-(ω² _p)/[ω(ω+i/τ)]formula 2

Wherein, in the case of silver,. epsilon_∞＝4；ω_pIs the bulk metal plasma frequency; τ is the scattering time as described above.

The transmittance of the silver films of 30nm and 5nm thickness was calculated using the above parameters, and is shown in FIG. 11. More particularly, fig. 11 illustrates exemplary plots 1100, 1150 of transmittance, reflectance, and absorbance versus frequency for silver films having thicknesses of 30nm and 5nm, respectively. As shown in fig. 11, the transmission is lower and flatter in the microwave spectrum and in a portion of the infrared spectrum from 300GHz to about 10THz, and increases in the remainder of the infrared spectrum and in the visible spectrum. As for the 5nm thick silver film, the transmittance in the microwave frequency range is about 0.03, which is close to 100% in the visible light spectrum. The loss for a 5nm thick silver film is about 15dB, which is significantly less than the 20+ dB loss for a 30nm thick silver film.

FIG. 12A illustrates the behavior of a window structure 1200 having a mw transmissive IR reflective metal layer 1210, the mw transmissive IR reflective metal layer 1210 coupled to a glass layer 1202, according to one embodiment. As shown in fig. 12A, the mw transmissive IR reflective metal layer 1210 allows at least some of the microwave signal 1204 to propagate through the window structure 1200. For example, if the mw transmitting IR reflecting metal layer 1210 is a discontinuous metal layer comprising metal islands, the mw transmitting IR reflecting metal layer 1210 allows the microwave signal 1204 to propagate through the openings between the metal islands.

Fig. 12B illustrates the behavior of a window structure 1250 having a low E metal film 1260, the low E metal film 1260 coupled to a glass layer 1252. As shown in fig. 12B, the low E metal film 1260 does not allow the microwave signal 1254 to propagate through the window structure 1250. In contrast, the low E metal film 1260 reflects the microwave signal 1254.

Referring to fig. 12A and 12B, even though the mw-transmissive IR-reflective metal layer 1210 and the low E metal film 1260 have the same amount of metal per unit area, there is a qualitative difference in the response of the mw-transmissive IR-reflective metal layer 1210 and the low E metal film 1260 to microwave signals. Note that the reflectivity increases dramatically with continuous film thickness. For example, silver films have a reflectivity of more than 65% for microwave signals with a frequency of 9.8GHz for a thickness of 20 nm. At optical frequencies, the skin depth (skin depth) becomes frequency independent and equal to c/ω_p20nm, where c 3 10¹⁰cm/s (i.e., speed of light). In one example, the skin depth is greater than the average size of the metal islands of the mw transmissive IR reflective metal layer (e.g., mw transmissive IR reflective metal layer 1210), corresponding to the thickness of the metal islands; whileThe skin depth at microwave frequencies is in the micrometer range. Although the interest in metal sub-wavelength feature scattering dates back to the beginning of the 1900 s, there has been no complete theories of micro-scale. Since the average size of the metal islands of the mw transmitting IR reflecting metal layer is significantly smaller than the wavelength of the incident microwave radiation, the brute force (brute force) numerical method may not be useful. Even the simpler case associated with sub-wavelength metal gratings that take into account finite conductivity is controversial. For mw transmitting IR reflecting metal layers, it is not possible to solve for the transmission of a given arbitrary structure, and then average all possible degrees of disorder. Therefore, it may be advantageous to devise an "equivalent" continuous film instead of a mw transmitting IR reflecting metal layer. However, such equivalence is currently unknown and may not exist.

However, since forward scattering is dominant in the subwavelength geometry, one can override the conventional quasi-static approximation by finding the field distributions of the metal islands and dielectric background separately and averaging the thickness of the mw transmitting IR reflecting metal layer and not averaging the length of the mw transmitting IR reflecting metal layer. The electric and magnetic fields (E and H) of the metal (um, vm) and dielectric (ud, vd) regions in the mw-transmitting IR-reflecting metal layer can be represented by the incident and scattered fields, respectively, in the common ohmic parameters (u, v). The parameter u represents the incident field strength. The parameter v represents the scattered field strength. The effective parameter (ue, ve) can then be determined by averaging the relevant ensembles of the parameters (um, vm) and (ud, vd), and the transmittance of the mw transmitting IR reflecting metal layer can be determined based on the effective parameter (ue, ve). For example, the parameters (um, vm) and (ud, vd) can be averaged using the equivalent media theory described in the classic paper "Berechung versener physicikalitcher konstantten von hectogenn substanzen" of D.A.G.Bruggeman, Annals of Physics, Vol.24, p.636-679, 1935.

Fig. 13 illustrates exemplary plots 1304, 1306 of transmittance, reflectance, and absorptance of a discontinuous metal layer versus metal fill fraction, according to an embodiment. The metal face fill fraction is the proportion of metal to metal layer. Plots 1304, 1306 show the transmittance, reflectance and absorptance, respectively, for a fixed incident radiation frequency. As shown in fig. 13, the transmission in the discontinuous metal layer approaches 100% when the metal face fill fraction is less than the percolation threshold 1308. Percolation threshold 1308 may correspond to a metal face fill fraction of approximately 0.5, although the scope of example embodiments is not limited in this respect. It should be noted that as the metal face fill fraction decreases, the transmission at microwave frequencies varies more dramatically from 0% to 100% than at infrared frequencies. This difference is most pronounced when the metal face fill fraction is close to (e.g., just below or including) the percolation threshold 1308. The metal layer included in the window is designed to have such a metal face fill fraction that the window transmits microwave frequencies while reflecting IR frequencies. The above-mentioned differences will be described in further detail later with reference to fig. 15 and 17.

Fig. 14A-14C are exemplary Scanning Electron Microscope (SEM) images 1400, 1430, 1460 of discontinuous gold layers having thicknesses of 4nm, 7nm, and 10nm, respectively, according to some embodiments. SEM images 1400, 1430, 1460 correspond to different metal face fill fractions. Each discontinuous gold layer may include gold islands randomly arranged in the discontinuous gold layer. The gaps between the randomly arranged gold islands may provide holes through the discontinuous gold layer for microwave signals to pass through.

Fig. 15 is an exemplary plot 1500 of the electrostatic conductivity of a discontinuous layer of gold versus the fractional fill of the metal surface, according to an embodiment. As shown in FIG. 15, when the metal face fill fraction decreases to the percolation threshold p_thIn the following, the conductivity of the discontinuous gold layer decreases by several orders of magnitude. The filling fraction of the metal surface is less than the penetration threshold value p_thCorresponding to a discontinuous layer of gold comprising gold grains separated by gaps to form gold islands. The gaps between the gold islands reduce the conductivity of the discontinuous gold layer. The reduced conductivity will result in a high microwave frequency transmission. When the metal surface filling fraction is larger than the penetration threshold value p_thGold islands are more likely to physically contact, leading to clustering of metal particles, thereby increasing the conductivity of the discontinuous gold layer. Increased conductivity will result in low microwave frequency transmission. It can be seen that the discontinuous gold layer is designed to have a penetration threshold p of less than_thThe metal surface filling rate of (2) may be beneficial to realizing transmission of microwave frequency and reflection of infrared frequency.

Fig. 16 illustrates a plot 1600 of conductivity versus frequency for a gold film and a gold layer including gold island structures, in accordance with an embodiment. The gold film has a metal face fill fraction greater than a percolation threshold; while the gold layer comprising the gold island structures has a metal face fill fraction less than the percolation threshold. Plot 1600 includes plots 1602, 1604, 1606, 1608, respectively representing the conductivity of each gold film with respect to the frequency range of 800MHz to 20 GHz. Plot 1600 further includes plots 1610, 1612, 1614, respectively representing the conductivity of each gold layer including the gold island structure with respect to the frequency range of 800MHz to 20 GHz. As shown in fig. 16, the conductivity of the gold film (corresponding to plots 1602, 1604, 1606, 1608) in the frequency range of 800MHz to 20GHz is greater than the gold layer (corresponding to plots 1602, 1604, 1606) including the gold island structure. Note the flat response versus frequency, as expected from the model in fig. 11. The conductivity is inversely proportional to the microwave transmittance, but the exemplary embodiments are not limited in this respect.

Fig. 17 illustrates plots 1702, 1704, 1752, 1754 of transmittance and reflectance of a discontinuous metal layer for a 10GHz microwave frequency and a 2.5 μm Near Infrared (NIR) light wavelength versus a metal plane fill fraction, according to an embodiment. Plots 1702, 1704 correspond to 10GHz microwave frequencies. In particular, plot 1702 represents the transmission versus metal fill fraction for microwave frequencies, and plot 1704 represents the reflection versus metal fill fraction for microwave frequencies. Plots 1752, 1754 correspond to NIR light frequencies. In particular, graph line 1752 represents the transmission of NIR light wavelengths versus the metal plane fill fraction, and graph line 1754 represents the reflection of NIR light wavelengths versus the metal plane fill fraction.

When the metal face fill fraction is less than the percolation threshold p, as shown by plot 1702_thWhen the transmittance of the microwave frequency is sharply increased; however, as shown by plot 1752, when the metal plane fill fraction is less than the percolation threshold p_thThe transmittance increase for NIR light wavelengths is more gradual. Thus, the difference between the transmission at microwave frequencies and the transmission at NIR light wavelengths is just below the percolation threshold p_thAnd larger (e.g., to a maximum value), the difference is smaller as the metal face fill fraction is further reduced. The work area of a certain metal surface filling fractional value range can be limited according to the design requirement. For example, the upper limit of the range may be selected to be close to (e.g., just less than, equal to, or just greater than) the percolation threshold p_thDisclosure of the inventionThe lower limit of the enclosure may be selected as the fractional fill value of the metal surface at which the difference between the transmission of microwave frequencies and the transmission of NIR light wavelengths is a critical difference. In another example, the upper and lower limits of the range are predetermined values. In fig. 17, by way of non-limiting example, the metal plane fill fraction value range of the active area may be selected to be 35% to 55%. It should be understood that the active area may fill a fractional value range for any suitable metal plane in which the relationship between the reflected IR signal and the reflected microwave signal is cut off. In the working region of fig. 17, the transmission is about 90% at microwave frequencies and the reflectance is about 35% -40% at NIR light wavelengths.

Fig. 18 illustrates exemplary steps of a process 1800 of fabricating a window having a discontinuous metal layer, according to an embodiment. In step 1 of process 1800, a continuous metal layer is deposited on an underlayer, which is on a substrate. In step 2 of process 1800, the continuous metal layer is altered to obtain a discontinuous metal layer. For example, if the continuous metal layer is deposited at a lower temperature in step 1, the continuous metal layer may be reverse-wetted (dewet) to obtain a discontinuous metal layer. In another example, if the continuous metal layer is deposited at a higher temperature in step 1, the higher temperature will cause the continuous metal layer to form islands resulting in a discontinuous metal layer. In step 3 of process 1800, an antireflective layer is deposited over the discontinuous metal layer. Since the thickness and lateral dimensions of the metal islands are significantly smaller than the wavelength of the microwave spectrum, the antireflective layer is essentially the same as that used with a continuous metal film. In step 4 of process 1800, a cap layer is placed on the anti-reflective layer to provide a first window structure. A second alternative window structure can be achieved by placing a dielectric layer between the bottom layer and the discontinuous metal layer, as shown in fig. 18.

FIG. 19 depicts an exemplary method flowchart 1900 for manufacturing a window structure, according to an embodiment. The flow chart may be performed by any suitable manufacturing machine. As shown in fig. 19, the method of flowchart 19 begins at step 1902. In step 1902, a glass layer is provided.

In step 1904, a metal layer is formed on the glass layer. Forming the metal layer includes configuring the metal layer to transmit signals having a frequency of 28GHz to 60GHz and to reflect signals having an infrared frequency. A metal layer may be deposited onto the glass layer or the metal layer and the glass layer may be bonded to form a metal layer on the glass layer. For example, the metal may be sprayed or sputter coated onto the glass layer.

In an exemplary embodiment, forming the metal layer in step 1904 includes configuring the metal layer to transmit signals having a frequency of 6GHz to 60GHz, 28GHz to 80GHz, or 6GHz to 80 GHz.

In another exemplary embodiment, forming the metal layer in step 1904 includes configuring the metal layer to have a resistance of at least a critical resistance to signals having a frequency of 28 gigahertz to 60 gigahertz. For example, the critical resistance may be 10M Ω or 100M Ω.

In yet another exemplary embodiment, forming the metal layer includes configuring the metal layer to reflect at least a critical percentage of signals having infrared frequencies in step 1904. For example, the critical percentage may be 30%, 35%, 40%, or 45%.

In yet another exemplary embodiment, forming the metal layer in step 1904 includes configuring the metal layer to have an electrical conductivity less than or equal to a critical electrical conductivity for signals having a frequency of 28 gigahertz to 60 gigahertz. For example, the critical conductivity may be 10^-6Siemens/m, 10^-5Siemens per meter or 10^-4Siemens per meter.

In another exemplary embodiment, forming the metal layer in step 1904 includes configuring the metal layer to provide at least 80% transmission in a frequency range of 6GHz to 80GHz, a frequency range of 6GHz to 60GHz, a frequency range of 28GHz to 80GHz, or a frequency range of 28GHz to 60 GHz.

In yet another exemplary embodiment, forming the metal layer in step 1904 includes configuring the metal layer as a discontinuous metal layer. For example, configuring the metal layer as a discontinuous metal layer may include configuring the metal layer as an electrically discontinuous metal layer. In another example, configuring the metal layer as a discontinuous metal layer may include configuring the metal layer as a physically discontinuous metal layer.

In a first aspect of this embodiment, disposing the metal layer includes disposing the discontinuous metal layer to have a face coverage of 35% to 55%.

In a second aspect of this embodiment, forming the metal layer includes depositing a metal layer onto the glass layer to provide the metal layer with a thickness less than the critical thickness in step 1904. According to a second aspect, a thickness less than a critical thickness may render the metal layer discontinuous (e.g., electrically and/or physically discontinuous).

In some example embodiments, one or more steps 1902 and/or 1904 of flowchart 1900 may not be performed. Further, additional steps may be performed in addition to or in place of steps 1902 and/or 1904. For example, in an exemplary embodiment, the method of flow chart 1900 further includes heating the metal layer to adhere the metal layer to the glass layer. In another exemplary embodiment, the method of flow chart 1900 further includes removing a portion of the metal layer in accordance with the metal layer to be formed on the glass layer. According to this embodiment, removing a portion of the metal layer may cause the metal layer to become discontinuous (e.g., electrically and/or physically discontinuous).

Fig. 20 illustrates an exemplary method flow diagram 2000 for using a window structure having a glass layer and a metal layer formed on the glass layer, according to an embodiment. The flowchart 2000 may be performed using the window structure 100 shown in fig. 1. For ease of illustration, flowchart 2000 will be described with reference to window structure 100. Other structural and operational embodiments will be apparent to those skilled in the relevant arts in view of the discussion related to flowchart 2000.

As shown in fig. 20, the method of flowchart 2000 begins at step 2002. In step 2002, an infrared signal having an infrared frequency is received in the metal layer. In an exemplary embodiment, the mw transmitting IR reflecting metal layer 110 receives infrared signals.

In step 2004, a microwave signal having a frequency of 28 gigahertz to 60 gigahertz is received in the metal layer. In an exemplary embodiment, mw transmits the microwave signal received by the IR reflecting metal layer 110.

In step 2006, a microwave signal is transmitted through the metal layer based at least in part on the configuration of the metal layer. In an exemplary embodiment, the mw transmissive IR reflective metal layer 110 transmits microwave signals based at least in part on the configuration of the mw transmissive IR reflective metal layer 110.

In step 2008, an infrared signal is reflected from the metal layer based at least in part on the configuration of the metal layer. In an exemplary embodiment, the mw transmitting IR reflecting metal layer 110 reflects infrared signals based at least in part on the configuration of the mw transmitting IR reflecting metal layer 110.

In an exemplary embodiment, transmitting the microwave signal includes transmitting the microwave signal through a metal layer based at least in part on the metal layer being a discontinuous metal layer in step 2006. For example, a microwave signal may be transmitted through the metal layer based at least in part on the metal layer being an electrically discontinuous metal layer. In another example, the microwave signal is transmitted through the metal layer based at least in part on the metal layer being a physically discontinuous metal layer.

In some example embodiments, one or more of steps 2002, 2004, 2006, and/or 2008 of flowchart 2000 may not be performed. Further, additional steps in addition to or in place of steps 2002, 2004, 2006, and/or 2008 may be performed.

Further discussion of some exemplary embodiments

A first exemplary window structure includes a glass layer and a metal layer. The metal layer is formed on the glass layer. The metal layer is configured to transmit signals having a frequency of 28 gigahertz to 60 gigahertz and is further configured to reflect signals having an infrared frequency.

In a first aspect of the first exemplary window structure, the metal layer is configured to transmit signals having a frequency of 6 gigahertz to 80 gigahertz.

In a second aspect of the first exemplary window structure, the metal layer has a resistance of at least 10 megaohms to a signal having a frequency of 28 gigahertz to 60 gigahertz. The second aspect of the first example window structure may be practiced in conjunction with the first aspect of the first example window structure, although example embodiments are not limited in this respect.

In a third aspect of the first exemplary window structure, the metal layer has a resistance of at least 100 megaohms to a signal having a frequency of 28 gigahertz to 60 gigahertz. The third aspect of the first example window structure may be practiced in conjunction with the first and/or second aspects of the first example window structure, although example embodiments are not limited in this respect.

In a fourth aspect of the first exemplary window structure, the metal layer is configured to reflect at least 20% of signals having infrared frequencies. The fourth aspect of the first example window structure may be practiced in conjunction with the first, second, and/or third aspects of the first example window structure, although example embodiments are not limited in this respect.

In a fifth aspect of the first exemplary window structure, the metal layer has a value of less than or equal to 10 for a signal having a frequency of 28 gigahertz to 60 gigahertz^-5Siemens/meter conductivity. The fifth aspect of the first example window structure may be practiced in conjunction with the first, second, third, and/or fourth aspects of the first example window structure, although the example embodiments are not limited in this respect.

In a sixth aspect of the first exemplary window structure, the metal layer provides a transmittance of at least 80% at a frequency range of 28GHz to 60 GHz. The sixth aspect of the first example window structure may be practiced in conjunction with the first, second, third, fourth, and/or fifth aspects of the first example window structure, although the example embodiments are not limited in this respect.

In a seventh aspect of the first exemplary window structure, the metal layer provides a transmittance of at least 80% at a frequency range of 6GHz to 80 GHz. The seventh aspect of the first example window structure may be practiced in conjunction with the first, second, third, fourth, fifth, and/or sixth aspect of the first example window structure, although the example embodiments are not limited in this respect.

In an eighth aspect of the first exemplary window structure, the metal layer is an electrically discontinuous metal layer. The eighth aspect of the first example window structure may be practiced in conjunction with the first, second, third, fourth, fifth, sixth, and/or seventh aspects of the first example window structure, although example embodiments are not limited in this respect.

In an eighth aspect of an embodiment of the first exemplary window structure, the electrically discontinuous metal layer has a face coverage of 35% to 55%.

A second exemplary window structure includes a glass substrate and a discontinuous metal layer. The discontinuous metal layer is configured to reflect infrared wavelengths. The discontinuous metal layer comprises a metal island structure having a thickness and lateral dimensions and disposed adjacent to the glass substrate. The thickness of the metal island structure is 1 to 7 nanometers. The lateral dimension of the metal island structures is on average at least 15 nanometers.

In a first aspect of the second exemplary window structure, the discontinuous metal layer has a face coverage of 35% to 55%.

In a second aspect of the second exemplary window structure, the discontinuous metal layer provides a transmittance of 0.4 to 1.0 for signals having a frequency of 6GHz to 80GHz and a reflectance of 0.3 to 0.6 for signals having a frequency of 30 terahertz to 75 terahertz. The second aspect of the second example window structure may be practiced in conjunction with the first aspect of the second example window structure, although example embodiments are not limited in this respect.

In a third aspect of the second example window structure, the discontinuous metal layer includes at least one of gold, silver, aluminum, or copper. The third aspect of the second example window structure may be practiced in conjunction with the first and/or second aspects of the second example window structure, although example embodiments are not limited in this respect.

In a fourth aspect of the second exemplary window structure, the second exemplary window structure further comprises a dielectric layer comprising Si₃N₄SnO, WO or LaB₆At least one of (a). According to a fourth aspect, the discontinuous metal layer is between the dielectric layer and the glass layer. The fourth aspect of the second example window structure may be practiced in conjunction with the first, second, and/or third aspects of the second example window structure, although example embodiments are not limited in this respect.

In a fifth aspect of the second exemplary window structure, the second exemplary window structure further comprises an antireflective layer between the glass substrate and the discontinuous metal layer, the antireflective layer comprising TiO₂SnO, WO or LaB₆At least one of (a). The fifth aspect of the second example window structure may be practiced in conjunction with the first, second, third, and/or fourth aspects of the second example window structure, although the example embodiments are not limited in this respect.

In an exemplary method of manufacturing a window structure, a glass layer is provided. The metal layer is formed on the glass layer. Forming the metal layer includes configuring the metal layer to transmit signals at a frequency of 28 gigahertz to 60 gigahertz and to reflect signals having an infrared frequency.

In a first aspect of the example method, forming the metal layer includes configuring the metal layer to transmit a signal having a frequency of 6 gigahertz to 80 gigahertz.

In a second aspect of the example method, forming the metal layer includes configuring the metal layer to have a resistance of at least 10 megaohms to a signal having a frequency of 28 gigahertz to 60 gigahertz. The second aspect of the example method may be practiced in conjunction with the first aspect of the example method, although the example embodiments are not limited in this respect.

In a third aspect of the example method, forming the metal layer includes configuring the metal layer to have a resistance of at least 100 megaohms to a signal having a frequency of 28 gigahertz to 60 gigahertz. The third aspect of the example method may be practiced in conjunction with the first and/or second aspects of the example method, although the example embodiments are not limited in this respect.

In a fourth aspect of the example method, forming the metal layer includes configuring the metal layer to reflect at least 30% of the signal having the infrared frequency. The fourth aspect of the example method may be practiced in conjunction with the first, second, and/or third aspects of the example method, although the example embodiments are not limited in this respect.

In a fifth aspect of the example method, forming the metal layer includes configuring the metal layer to have less than or equal to 10 for signals having a frequency of 28 gigahertz to 60 gigahertz^-5Siemens/meter conductivity. The fifth aspect of the example method may be practiced in conjunction with the first, second, third, and/or fourth aspects of the example method, although the example embodiments are not limited in this respect.

In a sixth aspect of the example method, forming the metal layer includes configuring the metal layer to provide a transmittance of at least 80% at a frequency range of 28GHz to 60 GHz. The sixth aspect of the example method may be practiced in conjunction with the first, second, third, fourth, and/or fifth aspect of the example method, although the example embodiments are not limited in this respect.

In a seventh aspect of the example method, forming the metal layer includes configuring the metal layer to provide at least 80% transmission at a frequency range of 6GHz to 80 GHz. A seventh aspect of the example method may be practiced in conjunction with the first, second, third, fourth, fifth, and/or sixth aspects of the example method, although the example embodiments are not limited in this respect.

In an eighth aspect of the example method, forming the metal layer includes configuring the metal layer as an electrically discontinuous metal layer. An eighth aspect of the example method may be practiced in conjunction with the first, second, third, fourth, fifth, sixth, and/or seventh aspects of the example method, although the example embodiments are not limited in this respect.

In a first embodiment of the eighth aspect of the exemplary method, configuring the metal layer includes configuring the electrically discontinuous metal layer to have a face coverage of 35% to 55%.

In a second embodiment of the eighth aspect of the exemplary method, forming the metal layer includes depositing the metal layer onto the glass layer to provide the metal layer with a thickness less than the critical thickness. According to a second embodiment, a thickness less than the critical thickness may cause the metal layer to become electrically discontinuous.

In a third embodiment of the eighth aspect of the example method, the example method further includes removing a portion of the metal layer in accordance with the metal layer to be formed on the glass layer. According to a third embodiment, removing a portion of the metal layer may cause the metal layer to become electrically discontinuous.

In an exemplary method of using a window structure having a glass layer and a metal layer formed on the glass layer, an infrared signal having an infrared frequency is received in the metal layer. A microwave signal having a frequency of 28 gigahertz to 60 gigahertz is received in the metal layer. Transmitting a microwave signal through the metal layer based at least in part on the configuration of the metal layer. The infrared signal is reflected from the metal layer based at least in part on the configuration of the metal layer.

In a first aspect of the exemplary method, transmitting the microwave signal includes transmitting the microwave signal through the metal layer based at least in part on the metal layer being an electrically discontinuous metal layer.

Conclusion IV

Although the subject matter has been described in language specific to structural features and/or acts, it is to be understood that the subject matter defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as example forms of implementing the claims, and other equivalent features and acts are intended to be within the scope of the claims.