A layered structure for a transparent microstrip patch antenna

Abstract

The invention relates to a layered structure for a microstrip patch antenna (10) comprising adjacent layers of a ground layer (12), a substrate (11), and a patch layer (13) in sequence. The ground layer (12) contains a first functional layer (122), containing a component selected from a group consisting of silver, copper, or gold metals, or their alloys, positioned below the substrate (11 ). The patch layer (13), positioned above the substrate (11), contains at least one second functional layer (132), composed of a component selected from a group consisting of silver, copper, or gold metals, or their alloys. The patch layer (13) has a total thickness of no more than 400 nm, adjusted to provide an optical transparency of at least 65% for visible light.

Description

[0001] DESCRIPTION

[0002] A LAYERED STRUCTURE FOR A TRANSPARENT MICROSTRIP PATCH ANTENNA

[0003] TECHNICAL FIELD

[0004] The invention relates to a multilayer structure designed for a microstrip patch antenna, which is used particularly for high-speed antenna applications, incorporating material designs that exhibit optical transparency.

[0005] PRIOR ART

[0006] A patch antenna (microstrip antenna) is a popular type of antenna for frequencies above 100 MHz, consisting of a ground plane, a substrate, and a patch. Patch antennas are low-profile, planar or non-planar surface compatible, easily integrated with microwave integrated circuits at low cost, and mechanically robust.

[0007] Optically transparent microstrip patch antennas use metal layers with a thickness of around 10 nm as radiating elements. However, reducing the thickness of the metal used as the radiating element increases sheet resistance (Rs), due to electron scattering at the surface boundaries, leading to high ohmic losses.

[0008] Another approach for achieving transparency in microstrip patch antennas is using transparent conductive films (TCF) as radiating elements. Indium tin oxide films are commonly used asTCF. However, their use increases costs and causes technical drawbacks, such as leakage at microwave frequencies when used in thinner layers compared to conventional metals like Ag, Cu, or Au. This is due to the skin depth at microwave frequencies being approximately 1 pm. As a result, microstrip patch antennas that incorporate TCF as radiating elements exhibit relatively weak performance. To address these issues, sandwich (three-layer) structures consisting of TCF / metal / TCF have been designed. By suppressing the reflection from the metal using TCF, both optical transparency and conductivity improve due to the reduction in equivalent resistance of the multilayer structure. In such three-layer sandwich structures, increasing the metal thickness improves antenna efficiency but reduces optical transmittance. BRIEF SUMMARY OF THE INVENTION

[0009] The objective of the present invention is to achieve a multilayer material with high metaldensity that possesses optical transparency for a microstrip patch antenna. In order to achieve the above objective, the invention is a layered structure fora microstrip patch antenna, comprising an adjacent and subsequent ground layer, a substrate, and a patch layer. The layered structure includes a first functional layer composed of a component selected from a group of metals such as silver, copper, or gold or their alloys, disposed adjacent to the substrate from below and the patch layer includes at least a second functional layer, also selected from a group of metals such as silver, copper, or gold or their alloys, disposed adjacent to the substrate from above, and the total thickness of the patch layer is adjusted to be no more than 400 nm, providing at least 65% optical transmittance in the visible wavelength range. The patch coating is set at most 280 nm, and the ground layer is set at most 80 nm.

[0010] BRIEF DESCRIPTION OF THE FIGURES

[0011] Figure 1 represents the schematic view of the layered structure for a microstrip patch antenna, showing the substrate, patch layer, and ground layer.

[0012] Figure 2 represents the schematic view of the layered structure for a microstrip patch antenna, showing the patch layer and ground layer containing a functional layer.

[0013] Figure 3 represents the schematic view of the layered structure for a microstrip patch antenna, showing the patch layer and ground layer containing two functional layers.

[0014] Figure 4 represents the schematic view of the layered structure for a microstrip patch antenna, showing the patch layer and ground layer containing three functional layers.

[0015] Figure 5 shows SEM analysis images of MLA-1 , MLA-2, and MLA-3 reference designs containing the layered structure of the invention.

[0016] Figure 6 shows the transmittance measurement values of ML -1 , MLA-2, and MLA-3 reference designs containing the layered structure when used in a microstrip patch antenna. REFERENCE NUMBERS

[0017] 10 Microstrip Patch Antenna

[0018] 11 Substrate

[0019] 12 Ground Layer

[0020] 121 First Dielectric Structure

[0021] 1211 First Dielectric Layer

[0022] 1212 Second Dielectric Layer

[0023] 1213Third Dielectric Layer

[0024] 122 First Functional Layer

[0025] 123 Second Dielectric Structure

[0026] 1231 Fourth Dielectric Layer

[0027] 1232 Fifth Dielectric Layer

[0028] 1233 Sixth Dielectric Layer

[0029] 13 Patch Layer

[0030] 131 Third Dielectric Structure

[0031] 1311 Seventh Dielectric Layer

[0032] 1312 Eighth Dielectric Layer

[0033] 1313 Ninth Dielectric Layer

[0034] 132 Second Functional Layer

[0035] 133 Fourth Dielectric Structure

[0036] 1321 Tenth Dielectric Layer

[0037] 1322 Eleventh Dielectric Layer

[0038] 1323 Twelfth Dielectric Layer

[0039] 134 Intermediate Dielectric Structure

[0040] 1341 Thirteenth Dielectric Layer

[0041] 1342 Fourteenth Dielectric Layer

[0042] 1343 Fifteenth Dielectric Layer

[0043] 135 Third Functional Layer

[0044] 136 Fourth Functional Layer DETAILED DESCRIPTION OF THE INVENTION

[0045] This detailed description addresses the layered structure used for microstrip patch antennas. The provided information serves to enhance understanding without affecting the scope of protection and is limited to informative examples.

[0046] A layered material is used forthe microstrip patch antenna. This structure contains at least one substrate. The substrate provides mechanical strength and electrical insulation to the antenna. Substrates can be made from one or more materials, such as ceramics, fiberglass, epoxy resin, or polymer-based materials.

[0047] In one implementation, a flexible material is used as the substrate. This flexible substrate increases the range of applications for microstrip patch antennas by allowing the multilayer structure to be applied to different shapes and uneven surfaces. Additionally, flexibility allows the microstrip patch antenna with the layered structure to be positioned in concealed designs or industrial products. Polymer-based materials are prominent as flexible materials. Examples of such materials include polycarbonate, polyphenylene oxide, polyacrylic, or polyurethane.

[0048] The layered structure for the microstrip patch antenna contains at least one ground layer (also known as a ground layer in the art). The ground layer is disposed adjacent to the substrate of the multilayer structure from below. The ground layer reduces electrical interference from the environment, provides electrical grounding, reduces parasitic radiation, and provides mechanical support when used in microstrip patch antennas. In Figure 1 , the position of the ground layer in the design of a microstrip patch antenna incorporating the layered structure described in the invention is shown schematically.

[0049] In a preferred embodiment of the invention, the ground layer contains at least one first functional layer. The first functional layer provides electrical conductivity to the structure. This first functional layer contains at least one of the metals silver, copper, or gold, or their alloys, or at least one of their oxides and / or nitrides. In a preferred implementation, the first functional layer contains silver metal or a silver-based alloy. In the most preferred embodiment, the first functional layer contains silver metal. In a preferred embodiment, the thickness of the first functional layer is in the range of 5 to 15 nm. In a more preferred embodiment, the thickness of the first functional layer is in the range of 7 to 12 nm.

[0050] In a preferred implementation, the first dielectric structure is disposed adjacent to and in contact below with the first functional layer. The first dielectric structure is positioned at the bottom of the final multilayered product.

[0051] The first dielectric structure contains at least one first dielectric layer. The first dielectric layer is positioned at the lowest part of the first dielectric structure. The first dielectric layer contains at least one of SixNy, SiOxNy, ZnAlOx, ZnSnOx, TiOx, TiNx, or ZrNx. In a preferred embodiment, the first dielectric layer contains a TiOx layer.

[0052] The thickness value of the first dielectric layer in a preferred embodiment is in range between 1 and 7 nm. In a more preferred embodiment, the thickness value of the first dielectric layer is in a range between 2 and 5 nm.

[0053] In a preferred implementation, the first dielectric structure contains at least one second dielectric layer. The second dielectric layer is positioned above and in contact with the first dielectric layer. The second dielectric layer contains at least one of SixNy, SiOxNy, ZnAlOx, ZnSnOx, TiOx, TiNx, or ZrNx. In a preferred embodiment, the second dielectric layer contains SixNy.

[0054] In a preferred embodiment, the thickness of the second dielectric layer is in the range of 20 to 30 nm. In a more preferred embodiment, the thickness of the second dielectric layer is in the range of 22 to 28 nm.

[0055] In a preferred implementation, the first dielectric structure contains at least one third dielectric layer. The third dielectric layer is positioned above and in contact with the second dielectric layer. The third dielectric layer is included to protect the silver-containing first functional layer in the first dielectric structure and to serve as a nucleating layer. The third dielectric layer contains at least one of NiCrOx, TiOx, ZnAlOx, or ZnOx. In a preferred embodiment, the first dielectric structure includes a third dielectric layer made of ZnAlOx. The thickness of the third dielectric layer in a preferred embodiment is between 5 and 15 nm. In a more preferred embodiment, the thickness of the third dielectric layer is between 7 and 12 nm. This specified thickness helps prevent the first functional layer from being exposed to oxygen load.

[0056] In a preferred embodiment, the ground layer includes a second dielectric structure located above and from above in contact with the first functional layer. The second dielectric structure in this invention improves optical transmittance and adhesion to the substrate, while also enhancing adhesion to the first functional layer.

[0057] In a preferred embodiment, the second dielectric structure contains at least one fourth dielectric layer. The fourth dielectric layer is positioned above and in contact with the first functional layer. The fourth dielectric layer is placed to protect the silver from oxidation in the second dielectric structure and to serve as a nucleating layer. The fourth dielectric layer contains at least one of NiCrOx, TiOx, ZnAlOx, or ZnOx. In a preferred embodiment, the second dielectric structure contains a fourth dielectric layer made of ZnAlOx. In a preferred embodiment, the second dielectric structure includes at least one fourth dielectric layer with a thickness in the range of 5 to 15 nm. In a more preferred embodiment, the thickness of the fourth dielectric layer is in the range of 7 to 12 nm. This ensures that the functional layer is not exposed to an oxygen load.

[0058] In a preferred embodiment, the second dielectric structure contains a fifth dielectric layer. The fifth dielectric layer is disposed above and from above in contact with the fourth dielectric layer. The fifth dielectric layer contains at least one of SixNy, SiOxNy, ZnAlOx, ZnSnOx, TiOx, TiNx, or ZrNx. In a preferred embodiment, the second dielectric structure contains a fifth dielectric layer made of SixNy. The thickness of the fifth dielectric layer in a preferred embodiment is in a range between 20 and 30 nm. In a more preferred embodiment, the thickness is in a range between 22 and 28 nm.

[0059] In a preferred embodiment, the second dielectric structure contains at least one sixth dielectric layer. The sixth dielectric layer is disposed above and from above in contact with the fifth dielectric layer. The sixth dielectric layer contains at least one of SixNy, SiOxNy, ZnAlOx, ZnSnOx, TiOx, TiNx, or ZrNx. In a preferred embodiment, the second dielectric structure contains a sixth dielectric layer made of TiOx. The thickness value of the sixth dielectric layer in a preferred embodiment is in the range between 1 and 7 nm. In a more preferred embodiment, the thickness is in the range between 2 and 5 nm. The specified thickness of the sixth dielectric layer ensures adherence to a superposed substrate. The multilayer structure of the invention includes at least one patch layer (also known as the patch layer in the art). This patch layer is located above the substrate in the microstrip patch antenna. The patch layer provides electrical conductivity, reflection, and absorption effects in the microstrip patch antenna. Figure 1 schematically shows the position of the patch layer in the design of the microstrip patch antenna.

[0060] In a preferred embodiment, the patch layer contains at least one second functional layer. The patch layer includes a second functional layer for electrical conductivity. The second functional layer contains at least one of the metals silver, copper, or gold, or their alloys, or at least one of their oxides and / or nitrides. In a preferred embodiment, the second functional layer contains silver metal or a silver-based alloy. The patch layer includes the second functional layer for electrical conductivity. In a preferred embodiment, the second functional layer contains silver metal or a silver-based alloy. In the most preferred embodiment, the second functional layer contains silver metal.

[0061] The patch layer, in a preferred embodiment, includes the second functional layer with a thickness of 5 to 15 nm. ln a more preferred embodiment, the second functional layer thickness is in a range between 7 and 12 nm.

[0062] In a preferred implementation, the patch layer includes a third dielectric structure located belowthe second functional layer and from above in contact with it. In a preferred embodiment, the third dielectric structure contains at least one seventh dielectric layer. The third dielectric structure contains at least one seventh dielectric layer, located above and from above in contact with the substrate. The seventh dielectric layer contains at least one of SixNy, SiOxNy, ZnAlOx, ZnSnOx, TiOx, TiNx, or ZrNx. In a preferred embodiment, the seventh dielectric layer contains TiOx. The thickness of the seventh dielectric layer in a preferred embodiment is between 1 and 7 nm. In a more preferred embodiment, the thickness is between 2 and 5 nm. This specified thickness helps ensure adhesion to the substrate.

[0063] In a preferred embodiment, the third dielectric structure contains at least one eighth dielectric layer. The eighth dielectric layer is positioned above and in contact with the seventh dielectric layer. The third dielectric structure includes, as the eighth dielectric layer, at least one of SixNy, SiOxNy, ZnAlOx, ZnSnOx, TiOx, TiNx, or ZrNx. In a preferred embodiment, the third dielectric structure contains the eighth dielectric layer as SixNy. In a preferred embodiment, the thickness of the eighth dielectric layer ranges between 20 and 30 nm. In a more preferred embodiment, the thickness of the eighth dielectric layer ranges between 22 and 28 nm.

[0064] In a preferred embodiment, the third dielectric structure contains at least one ninth dielectric layer. The ninth dielectric layer is positioned above and in contact with the eighth dielectric layer. The third dielectric structure includes, as the ninth dielectric layer, at leastone of NiCrOx, TiOx, ZnAlOx, or ZnOx. In a preferred embodiment, the third dielectric structure contains the ninth dielectric layer as ZnAlOx. In a preferred embodiment, thethickness of the ninth dielectric layer ranges between 5 and 15 nm. In a more preferred embodiment, the thickness of the ninth dielectric layer ranges between 7 and 12 nm. The specified thicknesses of the ninth dielectric layer help protect the second functional layer, which contains silver, from oxygen exposure and simultaneously provide nucleating functions.

[0065] In a preferred embodiment, the patch layer contains a fourth dielectric structure positioned above the second functional layer. In this invention, the fourth dielectric structure is included in the patch layer to enhance optical transparency, adhesion to the substrate, and adhesion to the first functional layer.

[0066] In a preferred embodiment, the fourth dielectric structure contains at least one tenth dielectric layer. The tenth dielectric layer is positioned above the second functional layer. The tenth dielectric layer is made from at least one of NiCrOx, TiOx, ZnAlOx, or ZnOx. In a preferred embodiment, the fourth dielectric structure contains the tenth dielectric layer as ZnAlOx. In a preferred embodiment, the thickness of the tenth dielectric layer ranges between 5 and 15 nm. In a more preferred embodiment, the thickness of the tenth dielectric layer ranges between 7 and 12 nm. The specified thicknesses of the tenth dielectric layer help protect the second functional layer, which contains silver, from oxygen exposure and simultaneously provide nucleating functions.

[0067] In a preferred embodiment, the fourth dielectric structure contains at least one eleventh dielectric layer. The eleventh dielectric layer is positioned above and in contact with the tenth dielectric layer. The fourth dielectric structure includes, as the eleventh dielectric layer, at least one of SixNy, SiOxNy, ZnAlOx, ZnSnOx, TiOx, TiNx, or ZrNx. In a preferred embodiment, the fourth dielectric structure contains the eleventh dielectric layer as SixNy. In a preferred embodiment, the thickness of the eleventh dielectric layer ranges between 20 and 30 nm. In a more preferred embodiment, the thickness of the eleventh dielectric layer ranges between 22 and 28 nm.

[0068] In a preferred embodiment, the fourth dielectric structure contains at least one twelfth dielectric layer. The twelfth dielectric layer is positioned above and in contact with the eleventh dielectric layer. The fourth dielectric structure includes, as the twelfth dielectric layer, at least one of SixNy, SiOxNy, ZnSnOx, ZnAlOx, TiZrOx, TiOx, TiNx, or ZrNx. In a preferred embodiment, the fourth dielectric structure contains the twelfth dielectric layer as TiOx. In a preferred embodiment, the thickness of the twelfth dielectric layer ranges between 1 and 7 nm. In a more preferred embodiment, the thickness of the twelfth dielectric layer ranges between 2 and 5 nm.

[0069] In a preferred embodiment of the invention, the patch layer contains at least two functional layers. The inclusion of at least two functional layers in the patch layer enhances the electrical conductivity properties of the final product's layered structure.

[0070] In a preferred embodiment, the patch layer contains both the second functional layer and the third functional layer. The mentioned third functional layer is positioned farther from the substrate than the second functional layer. The configuration of the patch layer containing the second functional layer and the third functional layer is shown in Figure 3.

[0071] In a preferred embodiment, the third functional layer contains at least one of silver, copper, or gold, or alloys of these metals in certain weight ratios, or at least one of their oxides and / or nitrides. In a preferred embodiment, the thickness of the third functional layer ranges between 5 and 15 nm. In a more preferred embodiment, the thickness of the third functional layer ranges between 7 and 12 nm. The patch layer includes the third functional layer to enhance electrical conductivity. In a preferred embodiment, the third functional layer contains silver metal or a silver-containing alloy. In the most preferred embodiment, the third functional layer contains silver metal.

[0072] With reference to Figure 3, in a preferred embodiment of the invention, the patch layer contains at least one intermediate dielectric structure between the second functional layer and the third functional layer. Due to the presence of metal-containing functional layers in the patch layer and the ground layer, the optical transparency values may decrease; however, the dielectric layers in the intermediate dielectric structure support the dielectric layers used in the ground layer, thus improving the optical transparency values, even resulting in a highly transparent coating.

[0073] In a preferred embodiment, the intermediate dielectric structure contains at least one thirteenth dielectric layer. The thirteenth dielectric layer is positioned above and in contact with the second functional layer. The thirteenth dielectric layer contains at least one of NiCrOx, TiOx, ZnAlOx, or ZnOx. In a preferred embodiment, the intermediate dielectric structure contains the thirteenth dielectric layer as ZnAlOx. In a preferred embodiment, the thickness of the thirteenth dielectric layer ranges between 5 and 15 nm. In a more preferred embodiment, the thickness of the thirteenth dielectric layer ranges between 7 and 12 nm. The specified thicknesses of the thirteenth dielectric layer help protect the third functional layer from oxidation and simultaneously provide nucleating functions.

[0074] In a preferred embodiment, the intermediate dielectric structure contains at least one fourteenth dielectric layer. The fourteenth dielectric layer is positioned above and in contact with the thirteenth dielectric layer. The fourteenth dielectric layer contains at least one of SixNy, SiOxNy, ZnSnOx, TiZrOx, TiOx, TiNx, or ZrNx. In a preferred embodiment, the intermediate dielectric structure contains the fourteenth dielectric layer as SixNy. In a preferred embodiment, the thickness of the fourteenth dielectric layer ranges between 30 and 75 nm. In a more preferred embodiment, the thickness of the fourteenth dielectric layer ranges between 40 and 60 nm.

[0075] In a preferred embodiment, the intermediate dielectric structure contains at least one fifteenth dielectric layer. The fifteenth dielectric layer is positioned above and in contact with the fourteenth dielectric layer. The fifteenth dielectric layer contains at least one of NiCrOx, TiOx, ZnAlOx, orZnOx. In a preferred embodiment, the intermediate dielectric structure contains the fifteenth dielectric layer as ZnAlOx. In a preferred embodiment, the thickness of the fifteenth dielectric layer ranges between 5 and 15 nm. In a more preferred embodiment, the thickness of the fifteenth dielectric layer ranges between 7 and 12 nm. The specified thicknesses of the fifteenth dielectric layer help protect the fourth functional layer from oxidation and simultaneously provide nucleating functions.

[0076] With reference to Figure 3, in the most preferred embodiment, the intermediate dielectric structure contains a ZnAlOx / SixNy / ZnAlOx sandwich structure, extending from the second functional layer to the third functional layer. This sandwich structure in the intermediate dielectric layer not only protects the functional layers but also improves the optical transparency values of the coating through the use of ZnAlOx.

[0077] In a preferred embodiment of the invention, when the patch layer contains two functional layers, the structure is configured, starting from the substrate and progressing outward, as follows: third dielectric structure / second functional layer / intermediate dielectric structure / third functional layer / fourth dielectric structure.

[0078] In a preferred embodiment of the invention, the patch layer contains three functional layers. The inclusion of three functional layers in the patch layer increases the electrical conductivity when the layered structure is used in a microstrip patch antenna.

[0079] In a preferred embodiment, the patch layer contains the second functional layer, the third functional layer, and the fourth functional layer. The mentioned fourth functional layer is positioned farther from the substrate than the second and third functional layers.

[0080] In a preferred embodiment, the fourth functional layer contains at least one of silver, copper, or gold, or their alloys in certain weight ratios, or at least one of their oxides and / or nitrides. The patch layer contains the fourth functional layer for electrical conductivity. In a preferred embodiment, the fourth functional layer contains silver metal or a silver-containing alloy. In the most preferred embodiment, the fourth functional layer contains silver metal.

[0081] In a preferred embodiment, the patch layer contains the fourth functional layer with a thickness ranging between 5 and 15 nm. In a more preferred embodiment, the thickness of the fourth functional layer ranges between 7 and 12 nm.

[0082] The configuration of the patch layer containing three functional layers is shown in Figure 4.

[0083] With reference to Figure 4, the patch layer contains at least one intermediate dielectric layer positioned between the third functional layer and the second functional layer.

[0084] In a preferred embodiment of the invention, if the patch layer contains three functional layers, the structure is configured, starting from the substrate and progressing outward, as follows: third dielectric structure / second functional layer / intermediate dielectric structure / third functional layer / intermediate dielectric structure / fourth functional layer / fourth dielectric structure.

[0085] TESTS

[0086] In this invention, the layered structure subject to testing consists of:

[0087] - A sequence of TiOx / SixNy / ZnAlOx layers referred to as 3L,

[0088] - A sequence of ZnAlOx / SixNy / ZnAlOx layers referred to as 3S.

[0089] Accordingly, the layered structure to be tested includes the following designs:

[0090] - MLA-1 design with a layer sequence of "3L / Ag / 3L / polycarbonate-based substrate / 3L / Ag / 3L",

[0091] MLA-2 design with a layer sequence of "3L / Ag / 3L / polycarbonate-based substrate / 3L / Ag / 3S / Ag / 3L",

[0092] MLA-3 design with a layer sequence of "3L / Ag / 3L / polycarbonate-based substrate / 3L / Ag / 3S / Ag / 3S / Ag / 3L".

[0093] These designs were tested to characterize their technical properties.

[0094] The layered structure in question was produced using a magnetic field sputtering system. The MLA-1 , MLA-2, and MLA-3 designs, consisting of different multilayer structures, were coated using an in-line magnetic field-assisted sputtering method. The multilayer structures include a conductive Ag layer, an adhesion-enhancing layer between Agand the polycarbonate substrate (PC), and protective layers above the Ag layer.

[0095] Initially, samples containingthe layered structure from this invention, correspondingto MLA-1 , MLA-2, and MLA-3 designs, were characterized using Scanning Electron Microscopy (SEM). The obtained images are shared in Figure 5.

[0096] The surface resistance values of the MLA-1 , MLA-2, and MLA-3 multilayer structures were measured using a four-point probe technique. In this technique, a current is applied through two outer probes, and a voltage is measured through two inner probes. The resistivity is then calculated using the current and voltage values. The surface resistances of the produced structures were measured using the four-point probe technique (Keithley 224 Programmable Current Source and 2000 Multimeter). Table 1 shows the surface resistances of the tested samples.

[0097] Table 1. Surface resistances of the tested samples.

[0098] The optical transparency values of the MLA-1 , MLA-2, and MLA-3 multilayer structures were measured across a wavelength range of 280 nm - 2500 nm using a Perkin Elmer Lambda 1050 UV / Vis / IR Spectrometer. The obtained results are shared in Figure 6.

[0099] With reference to Figure 6, the MLA-1 design shows the highest transparency value, reaching 90% at a wavelength of 550 nm. Additionally, the MLA-1 design exhibits the highest transparency value throughout the visible wavelength range (380 nm - 780 nm). Although the MLA-3 design has the lowest transparency value among them, its transparency value remains above 65% across the visible wavelength range. Despite having the lowest transparency value, the MLA-3 design exhibits lower resistance than MLA-2 and MLA-1 designs, suggesting that it will provide higher antenna efficiency in antenna applications. Moreover, the MLA-3 design, which does not have transparency values below 65% in the visible wavelength range, is expected to have at least 65% transparency and high antenna efficiency in the relevant technical field. Therefore, it has been determined that the designs intended for microstrip patch antennas in this invention will achieve at least 65% transparency in the visible wavelength range and provide high antenna efficiency depending on the amount of silver present in the patch layer.

[0100] By increasing the total thickness of the metal-containing layers in the layered structure of this invention, the antenna efficiency and peak gain are improved when used in a microstrip patch antenna, while the dielectric layers used in the structure ensure that optical transparency values are not compromised. To achieve the aforementioned technical features and advantages, the patch layers, ground layers, and the layers they contain in the microstrip patch antenna design are determined and positioned according to research and development activities, ensuring the layers are located at the specified positions and within the specified thickness ranges.

Claims

CLAIMS1. A layered structure for a microstrip patch antenna (10) comprising adjacent layers of a ground layer (12), a substrate (11 ), and a patch layer (13) in sequence, characterized by, the ground layer (12) having a first functional layer (122) containing a component selected from a group consisting of silver, copper, gold metals, or their alloys, preferably silver metal or a silver-containing alloy, positioned below the substrate (11 ); the patch layer (13), positioned above the substrate (11), has at least one second functional layer (132) composed of a component selected from a group consisting of silver, copper, gold metals, or their alloys, preferably silver metal or a silver-containing alloy, with a total thickness of no more than 400 nm, adjusted to provide an optical transparency of at least 65% for visible light.

2. The layered structure according to Claim 1 , wherein the ground layer (12) comprises, in sequence: a first dielectric structure (121) containing at least one of SixNy, SiOxNy, ZnAlOx, ZnSnOx, TiOx, TiNx, orZrNx, the first functional layer (122) positioned adjacent to and from above in contact with the first dielectric structure (121); a second dielectric structure (123) containing at least one of SixNy, SiOxNy, ZnAlOx, ZnSnOx, TiOx, TiNx, or ZrNx, disposed adjacent to and from above in contact with the first functional layer (122).

3. The layered structure according to Claim 2, wherein the first dielectric structure (121 ) further comprises, in sequence: a first dielectric layer (1211 ) containing at least one of SixNy, SiOxNy, ZnAlOx, ZnSnOx, TiOx, TiNx, or ZrNx, preferably TiOx; a second dielectric layer (1212) positioned adjacent to and from above in contact with the first dielectric layer (1211), containing at least one of SixNy, SiOxNy, ZnAlOx, ZnSnOx, TiOx, TiNx, or ZrNx, preferably SixNy; a third dielectric layer (1213) positioned adjacent to and from above in contact with the second dielectric layer (1212), containing at least one of NiCrOx, TiOx, ZnAlOx, orZnOx, preferably ZnAlOx.

4. The layered structure according to Claim 2 or Claim 3, wherein the second dielectric structure (123) further comprises, in sequence: a fourth dielectric layer (1231) containing at least one of NiCrOx, TiOx, ZnAlOx, or ZnOx, preferably ZnAlOx; a fifth dielectric layer (1232) positioned adjacent to and from above in contact with the fourth dielectric layer (1231), containing at least one of SixNy, SiOxNy, ZnAlOx, ZnSnOx, TiOx, TiNx, or ZrNx, preferably SixNy; a sixth dielectric layer (1233) positioned adjacent to and from above incontact with the fifth dielectric layer (1232), containing at least one of SixNy, SiOxNy, ZnAlOx, ZnSnOx, TiOx, TiNx, or ZrNx, preferably TiOx.

5. The layered structure according to any of the preceding claims, wherein the ground layer (12) further comprises, in sequence: a first dielectric layer (1211 ) with a thickness selected between 1 and 7 nm, composed of TiOx; a second dielectric layer (1212), positioned adjacent to and from above in contact with the first dielectric layer (1211), with a thickness selected between 20 and 30 nm, composed of SixNy; a third dielectric layer (1213), positioned adjacent to and from above in contact with the second dielectric layer (1212), with a thickness selected between 5 and 15 nm, composed of ZnAlOx; a first functional layer (122) positioned adjacent to and from above in contact with the third dielectric layer (1213), with a thickness selected between 5 and 15 nm, composed of silver; a fourth dielectric layer (1231) positioned adjacent to and from above in contact with the first functional layer (122), with a thickness selected between 5 and 15 nm, composed of ZnAlOx; a fifth dielectric layer (1232) positioned adjacent to and from above in contact with the fourth dielectric layer (1231), with a thickness selected between 5 and 15 nm, composed of SixNy; a sixth dielectric layer (1233) positioned adjacent to and from above in contactwith the fifth dielectric layer (1232), with a thickness selected between 1 and 7 nm, composed of TiOx.

6. The layered structure according to any of the preceding claims, wherein the substrate (11) is composed of a polymer selected from the group of polyacrylic, polycarbonate, polyphenylene oxide, or polyurethane.

7. The layered structure according to any of the preceding claims, wherein the patch layer (13) further comprises, in sequence: a third dielectric structure (131) positioned adjacent to and from above in contact with the substrate (11 ); a second functional layer (132), composed of silver, positioned adjacent to and from above in contactwith the third dielectric structure (131); a fourth dielectric structure (133) positioned adjacent to and from above in contact with the second functional layer (132).

8. The layered structure according to Claim 7, wherein the third dielectric structure (131 ) further comprises, in sequence: a seventh dielectric layer (1311) containing at least one of SixNy, SiOxNy, ZnAlOx, ZnSnOx, TiOx, TiNx, or ZrNx, preferably TiOx; an eighth dielectric layer (1312) positioned adjacent to and from above in contact with the seventh dielectriclayer (1311), containing at least one of SixNy, SiOxNy, ZnAlOx, ZnSnOx, TiOx, TiNx, orZrNx, preferably SixNy; a ninth dielectric layer (1313) positioned adjacent to and from above in contact with the eighth dielectric layer (1312), containing at least one of NiCrOx, TiOx, ZnAlOx, orZnOx, preferably ZnAlOx.

9. The layered structure according to any of Claims 7 or 8, wherein the fourth dielectric structure (133) further comprises, in sequence: a tenth dielectric layer (1321 ) containing at least one of NiCrOx, TiOx, ZnAlOx, or ZnOx, preferably ZnAlOx; an eleventh dielectric layer (1322) positioned adjacent to and from above in contact with the tenth dielectric layer (1321), containing at least one of SixNy, SiOxNy, ZnAlOx, ZnSnOx, TiOx, TiNx, or ZrNx, preferably SixNy; a twelfth dielectric layer (1323) positioned adjacent to and from above in contact with the eleventh dielectric layer (1322), containing at least one of SixNy, SiOxNy, ZnSnOx, ZnAlOx, TiZrOx, TiOx, TiNx, or ZrNx, preferably TiOx.

10. The layered structure according to Claim 1 , wherein the patch layer (13) further comprises a second functional layer (132) and a third functional layer (135) containing at least one of silver, copper, gold metals, or their alloys.11 . The layered structure according to Claim 10, wherein the patch layer (13) comprises: the second functional layer (132) positioned closertothe substrate (11) and the third functional layer (135) positioned farther from the substrate (11 ); at least one intermediate dielectric structure (134) positioned between the second functional layer (132) and the third functional layer (135).

12. The layered structure according to any of Claims 10 or 11 , wherein the patch layer (13) further comprises, in sequence: a third dielectric structure (131) positioned adjacent to and from above in contact with the substrate (11 ); a second functional layer (132), composed of silver, positioned adjacent to and from above in contact with the third dielectric structure (131); an intermediate dielectric structure (134) positioned between the second functional layer (132) and the third functional layer (135); a third functional layer (135), composed of silver, positioned adjacent to and from above in contact with the intermediate dielectric structure (134); a fourth dielectric structure (133) positioned adjacent to and from above in contact with the third functional layer (135).

13. The layered structure according to Claim 12, wherein the third dielectric structure (131) further comprises, in sequence: a seventh dielectric layer (1311) containing at least one of SixNy, SiOxNy, ZnAlOx, ZnSnOx, TiOx, TiNx, or ZrNx, referably TiOx; an eighth dielectric layer (1312) positioned adjacent to and from above in contact with the seventh dielectric layer (1311), containing at least one of SixNy, SiOxNy, ZnAlOx, ZnSnOx, TiOx, TiNx, or ZrNx, preferably SixNy; a ninth dielectric layer (1313) positioned adjacent to and from above in contact with the eighth dielectric layer (1312), containing at least one of NiCrOx, TiOx, ZnAlOx, orZnOx, preferably ZnAlOx.

14. The layered structure according to any of Claims 12 or 13, wherein the fourth dielectric structure (133) further comprises, in sequence: a tenth dielectric layer (1321 ) containing at least one of NiCrOx, TiOx, ZnAlOx, or ZnOx, preferably ZnAlOx; an eleventh dielectric layer (1322) positioned adjacent to and from above in contact with the tenth dielectric layer (1321), containing at least one of SixNy, SiOxNy, ZnAlOx, ZnSnOx, TiOx, TiNx, or ZrNx, preferably SixNy; a twelfth dielectric layer.

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