Wireless communication device

Abstract

To provide a radio communication device capable of suppressing thermal cracking of a glass plate.SOLUTION: A wireless communication device includes a heating element provided in a structure part in contact with an end part of a glass plate, and an antenna provided in the glass plate, and is adjusted so that a temperature difference between the heating element and the antenna is 50 °C or less.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to wireless communication devices. [Background technology]

[0002] Conventionally, there have been glass antenna units that are installed on the indoor side of a glass plate and transmit and receive electromagnetic waves from the indoor side through the glass plate. The glass antenna unit has an antenna, and a space through which air can flow is provided between the glass plate and the antenna. That is, the antenna is attached to the glass plate facing the glass plate with a gap between them. The antenna is also optically transparent.

[0003] If the air flow near the antenna is obstructed, the temperature of the antenna will rise, causing the temperature of the portion of the glass plate facing the antenna to rise, which may cause thermal cracking of the glass plate due to the difference in thermal expansion coefficients.To prevent such thermal cracking of the glass plate, a space is provided between the glass plate and the antenna through which air can flow.

[0004] Furthermore, by separating the antenna from the window frame by a predetermined distance (e.g., 20 mm) or more when viewed in plan on the glass plate, the temperature gradient between the part of the outer edge of the glass facing the antenna and the part of the glass plate located within the window frame is reduced, thereby suppressing thermal cracking (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] International Publication No. 2019 / 026963 Summary of the Invention [Problem to be solved by the invention]

[0006] Although the antenna of a conventional glass antenna unit (wireless communication device) has optical transparency, it is less transparent than the optical transparency of the glass plate, so when attaching the antenna to the glass plate, it is preferable to attach it to the edge of the glass plate rather than the center, because if it is attached to the center of the glass plate, it will impair visibility to some extent.

[0007] Conventional glass antenna units have taken measures such as providing a space between the glass plate and the antenna to allow air to flow, or separating the antenna from the window frame by a predetermined distance or more, but there is room for consideration of other measures as well.

[0008] Therefore, an object of the present invention is to provide a wireless communication device that can suppress thermal cracking of the glass plate. [Means for solving the problem]

[0009] A wireless communication device according to an embodiment of the present disclosure includes a heating element provided in a structural part that contacts the edge of a glass plate, and an antenna provided on the glass plate, and is adjusted so that the temperature difference between the heating element and the antenna is 50°C or less. [Effects of the Invention]

[0010] A wireless communication device can be provided that can suppress thermal cracking of the glass plate. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a diagram illustrating an example of a building in which a window in which a wireless communication device according to an embodiment is installed is installed. [Figure 2] 1 is a diagram illustrating a configuration of a wireless communication device according to an embodiment. [Figure 3] 1 is a diagram illustrating a configuration of a wireless communication device according to an embodiment. [Figure 4] 1 is a diagram illustrating a configuration of a wireless communication device according to an embodiment. [Figure 5] 1 is a diagram illustrating a configuration of a wireless communication device according to an embodiment. [Figure 6] 1 is a diagram illustrating a configuration of a wireless communication device according to an embodiment. [Figure 7] 2 is a block diagram illustrating an example of the configuration of a control unit and a temperature sensor of the wireless communication device according to the embodiment. FIG. [Figure 8] FIG. 10 is a diagram showing an example of parameters in a simulation (part 1). [Figure 9] FIG. 10 is a diagram showing an example of a temperature distribution obtained by a simulation (part 1). [Figure 10A] FIG. 10 is a diagram showing an example of a simulation result of stress distribution. [Figure 10B] FIG. 10 is a diagram showing an example of a simulation result of stress distribution. [Figure 11] FIG. 10 is a diagram showing an example of the results of a simulation (part 2) that calculates stress due to the temperature difference between the driving unit and the antenna. [Figure 12] FIG. 2 is a diagram showing an example of the configuration of a transparent conductor. [Figure 13] FIG. 10 is a diagram illustrating an example of a configuration of a wireless communication device according to a modified example of the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, an embodiment to which the wireless communication device of the present disclosure is applied will be described. In the following, the same elements will be denoted by the same reference numerals, and duplicated descriptions may be omitted.

[0013] In the following description, the XYZ coordinate system is defined. The direction parallel to the X axis (X direction), the direction parallel to the Y axis (Y direction), and the direction parallel to the Z axis (Z direction) are perpendicular to one another. The XYZ coordinate system is an example of a Cartesian coordinate system. In the following description, the length, width, thickness, etc. of each part may be exaggerated to make the configuration easier to understand. Furthermore, terms such as parallel, right angle, orthogonal, horizontal, vertical, up and down, etc., are allowed to be misaligned to the extent that they do not impair the effects of the embodiments.

[0014] In the following explanation, "radio waves" refers to a type of electromagnetic wave, and generally, electromagnetic waves below 3 THz are called radio waves. In the following, electromagnetic waves below 3 THz emitted from an outdoor base station or relay station will be called "radio waves," and when referring to electromagnetic waves in general, they will be called "electromagnetic waves."

[0015] The radio waves relayed by the wireless communication device of the embodiment are preferably radio waves in the millimeter wave band of the fifth generation mobile communication system (5G) or the 1 GHz to 30 GHz frequency band including Sub-6. The radio waves relayed by the wireless communication device of the embodiment may be LTE (Long Term Evolution), LTE-Advanced (LTE-A), UMB (Ultra Mobile Broadband), or CBRS (Citizens Broadband Radio Service). The radio waves relayed by the wireless communication device of the embodiment may be IEEE802.11 (Wi-Fi (registered trademark)), IEEE802.16 (WiMAX (registered trademark)), IEEE802.20, UWB (Ultra-Wideband), Bluetooth (registered trademark), LPWA (Low Power Wide Area), or the like. As the frequency of the radio waves increases, propagation loss due to reflection and diffraction increases, making it more likely that blind zones will occur. Therefore, the wireless communication device of the embodiment is more suitable for communications using relatively high frequencies.

[0016] <Embodiment> FIG. 1 is a diagram showing an example of a building 1 in which a window 10 equipped with a wireless communication device 100 according to an embodiment is installed. The building 1 may be a detached house, a building, an apartment building, or a commercial facility such as a shopping mall or a department store, an airport, a factory, a power facility, a government building, a train station (station building), or a bus stop building. The window 10 is used in these buildings 1. The window 10 includes window glass and a window frame. The wireless communication device 100 includes a repeater. The repeater is a CPE (Customer Premises Equipment) or a repeater, or the like.

[0017] Radio waves emitted from an outdoor base station enter the building through the glass of window 10 of building 1. Wall 1A of building 1 acts as a shield for millimeter wave radio waves, preventing them from passing through or significantly attenuating them. Millimeter wave radio waves are already attenuated by the time they reach building 1, and are further attenuated by the window glass. The glass of window 10 is the entrance into building 1 for electromagnetic waves.

[0018] If the wireless communication device 100 is not installed, radio waves will pass through the window glass of the window 10 and travel in a straight line, so areas other than within the line of sight (LOS) will become blind zones and radio waves cannot be received.

[0019] Millimeter wave radio waves differ from conventional mobile communication systems such as 3G (Third Generation) and 4G (Fourth Generation) in that it is difficult to create a good communication environment indoors due to the radiation of radio waves from outdoor base stations. Therefore, wireless communication device 100 is installed in window 10 to improve the reception environment and expand the communication area. The repeater of wireless communication device 100 receives radio waves through the window glass of window 10, amplifies them, and radiates them. In FIG. 1, wireless communication device 100 is installed indoors, but it may also be installed outdoors.

[0020] The wireless communication device 100 functions as a repeater that amplifies received radio waves and radiates the amplified radio waves at a predetermined radiation angle using an array antenna, etc. The amplified radio waves are radiated from the repeater to a wide area indoors, making it easy for indoor terminals to receive the radio waves.

[0021] For example, a repeater may receive radio waves of multiple frequencies, amplify them, and radiate them. Also, multiple repeaters may be provided. In this case, each repeater may be configured to relay radio waves of a different frequency. Furthermore, by using multiple repeaters, the amplified radio waves can be radiated over a wider area indoors.

[0022] <Configuration of wireless communication device 100> 2 to 6 are diagrams showing the configuration of the wireless communication device 100. Fig. 2 is a perspective view showing an example of the wireless communication device 100 attached to a window 10. The window 10 includes a window pane 11 and a window frame 12. The window pane 11 is an example of a glass plate.

[0023] Fig. 3 is a side view showing an example of a state in which the wireless communication device 100 is attached to a window 10. Fig. 3 shows a cross section of a window glass 11 and a window frame 12. Fig. 4 is a perspective view showing an example of the wireless communication device 100. Fig. 5 is a perspective view showing an example of the wireless communication device 100 in an exploded state. Fig. 6 is a perspective view showing an example of an array antenna 111A and a matching layer 115B in an exploded state.

[0024] In the following, an example will be described in which the window 10 is a fixed window, but it may also be a sliding window or a casement window that can be opened and closed. Also, an example will be described in which a single pane of window glass 11 is held by a window frame 12, but it may also be double-glazed.

[0025] The window glass 11 may be made of commonly available glass, such as soda-lime glass, alkali-free glass, Pyrex (registered trademark) glass, quartz glass, etc. The window glass 11 is not limited to a glass plate, and may also be a surface material made of resin such as polycarbonate.

[0026] The window frame 12 is a frame-shaped member that surrounds the edge of the window glass 11, and is made of metal such as aluminum, or resin, etc. Below, an example in which the window frame 12 is made of metal will be described.

[0027] The window glass 11 and window frame 12 of the window 10 are provided on a wall 1A that is perpendicular to a horizontal plane. The indoor main surface 11A of the window glass 11 is parallel to the indoor surface 12A of the window frame 12, and the thickness (thickness in the Z direction) of the window glass 11 and the window frame 12 is constant. The indoor side is an example of a first side of the window glass 11 and the window frame 12, and the outdoor side is an example of a second side of the window glass 11 and the window frame 12.

[0028] The wireless communication device 100 includes an antenna 110, a matching layer 115B, a waveguide 120, a driver 130, and a bracket 140. The waveguide 120 is an example of a transmission path. The driver 130 is an example of a heating element provided on a structural part (window frame 12) that contacts the edge of a glass plate (window glass 11). The bracket 140 is an example of a fixture. The wireless communication device 100 is provided on the indoor side of a building 1 (see FIG. 1 ), for example. Note that, while the wireless communication device 100 includes the waveguide 120 in this example, the following transmission path may be used instead of the waveguide 120. For example, an FPC (Flexible Printed Circuit) transmission path may be used, which has a transmission line such as a microstrip line (MSL) or a coplanar waveguide (CPW) formed on a flexible substrate such as polyimide. The FPC transmission path is an example of a transmission path having a flexible substrate and a transmission line such as an MSL or a CPW formed on the flexible substrate.

[0029] Here, the XYZ coordinate system is defined based on the indoor surface 12A of the window frame 12 to which the drive unit 130 is attached. The X axis is an example of the first axis, the Y axis is an example of the second axis, and the Z axis is an example of the third axis. The X direction is an example of the first axis direction, the Y direction is an example of the second axis direction, and the Z direction is an example of the third axis direction.

[0030] The indoor-side surface 12A of the window frame 12 is a surface including the X and Y directions. The surface 12A is parallel to the XY plane and is an example of a first surface. The Z direction is a direction perpendicular to the surface 12A and is the direction of the normal to the surface 12A. The +Z direction side of the surface 12A is the indoor side. The Y direction in this XYZ coordinate system is the direction connecting the drive unit 130 and the window glass 11. The X direction is the direction in which the window frame 12 extends along the outer edge 11E of the window glass 11 (see Figures 2 and 3) at the fixed position of the drive unit 130 to the window frame 12. The fixed position of the drive unit 130 to the window frame 12 is the position where two brackets 140 are attached to the frame-shaped window frame 12. In Figure 2, this is the portion of the window frame 12 that is on the +Y direction side of the window glass 11 and extends in the X-axis direction. The outer edge 11E of the window glass 11 is part of the outer edge (outer edge) when the window glass 11 is viewed in the XY plane (planar view), and is the part of the frame-shaped outer edge of the window glass 11 that is on the +Y direction side of the window glass 11 and extends in the X-axis direction.

[0031] Such outer edge 11E is an example of an edge of a glass plate. The portion of window frame 12 that contacts outer edge 11E is an example of a structural portion that contacts the edge of a glass plate. The portion of window frame 12 that contacts outer edge 11E is a portion of window frame 12 that extends in the X direction on the +Y direction side.

[0032] Although the following describes a configuration in which the window glass 11 is rectangular in plan view and the window frame 12 is frame-shaped (rectangular ring-shaped) in plan view, the window glass 11 is not limited to being rectangular in plan view, and may be shaped such that the outer edge 11E is curved, such as circular or elliptical. In this case, the window frame 12 may be a frame-shaped member that surrounds the window glass 11 having such a curved outer edge 11E.

[0033] Further, although the embodiment in which the drive unit 130 is provided on the window frame 12 is described here, the drive unit 130 may also be provided on a structural part such as a wall located near the windowpane 11.

[0034] Additionally, here, a form will be described in which the driver 130, as an example of a heating element provided in a structural part that contacts the edge of the glass sheet, is provided in a structural part such as the window frame 12, but the driver 130 may also be provided on the antenna 110 side or on a desk near the window. In this case, a heating element separate from the driver 130 may be provided in the structural part such as the window frame 12. Such a heating element may be, for example, a heater with an electric heating wire or another type of heater. Details of how to use the heating element provided in the structural part such as the window frame 12 will be described later.

[0035] 2 to 6, the X and Z directions are horizontal directions, and the XZ plane is parallel to the horizontal plane. The Y direction is the vertical direction, the +Y direction is the vertically upward direction, and the -Y direction is the vertically downward direction. In the following description, the +Y direction side is the upper side and the -Y direction side is the lower side.

[0036] The wireless communication device 100 uses heat generated by the drive unit 130 to suppress thermal cracking in the portion of the window glass 11 between the antenna 110 and the drive unit 130. At this time, the drive unit 130 adjusts the temperature difference between the drive unit 130 and the antenna 110 to 50°C or less. Thermal cracking occurs when the temperature gradient of the window glass 11 increases, causing a local difference in the thermal expansion coefficient and increasing the stress applied to the window glass 11.

[0037] <Antenna 110> The antenna 110 is, for example, rectangular in XY plane view, and is adhered to the indoor main surface 11A of the window glass 11 with double-sided tape 115A1 (see FIG. 5). That is, the antenna 110 is disposed on the indoor side of the window glass 11. The antenna 110 includes a substrate 111, an array antenna 111A, a cover 112, and a temperature sensor 113. The temperature sensor 113 is an example of a second temperature sensor, and the temperature detected by the temperature sensor 113 is an example of a second temperature. The array antenna 111A is, for example, formed on the surface of the substrate 111 on the -Z direction side (see FIG. 6), and is located inside the outer edge of the rectangular cover 112 in XY plane view.

[0038] The array antenna 111A is provided at a distance in the Z direction from a matching layer 115B provided on the indoor main surface 11A of the window glass 11, and is located inside the matching layer 115B when viewed in the XY plane. Therefore, the array antenna 111A is not in contact with the matching layer 115B or the window glass 11, but faces the matching layer 115B. The +Z direction side of the substrate 111 on which the array antenna 111A is formed is covered with a transparent cover 112.

[0039] <Substrate 111> The substrate 111 is fixed to the surface on the −Z direction side of the main body 112A of the cover 112. The substrate 111 is fixed to the main body 112A of the cover 112 with, for example, double-sided tape or adhesive.

[0040] The substrate 111 is formed of any material that is transparent to radio waves emitted from an outdoor base station and that can support the array antenna 111A and the temperature sensor 113. "Transparent" means that the luminous transmittance is at least 40% or more, preferably 60% or more, more preferably 70% or more, and even more preferably 80% or more. As an example, a resin base material is used for the substrate 111. Examples of resin materials that satisfy the above conditions include acrylic resins such as polymethyl methacrylate, cycloolefin resins, polycarbonate resins, polyethylene terephthalate (PET), and the like. The substrate 111 may also be a glass plate.

[0041] The array antenna 111A is formed of a conductor. Because the antenna 110 is disposed over the window 10, the array antenna 111A is preferably formed of a transparent conductive film such as zinc oxide (ZnO), tin oxide (SnO2), tin-doped indium oxide (ITO), or indium oxide-tin oxide (IZO), a metal nitride such as titanium nitride (TiN) or chromium nitride (CrN), or a low-e (low emissivity) film for low-e glass. However, the array antenna 111A may also be formed of a metal thin film such as copper, nickel, or gold. In the case of a metal thin film, it is preferable to form it in a mesh shape from the viewpoint of visibility.

[0042] The array antenna 111A has multiple antenna elements arranged two-dimensionally in the XY plane to perform beamforming. Each antenna element is connected to a phase adjustment circuit that adjusts the phase of the received radio waves. As an example, the phase adjustment circuit can be made of LC (Liquid Crystal).

[0043] <Cover 112> Cover 112 is a cover made of transparent glass or resin, and has a main body 112 A and leg portions 112 B. Here, “transparent” means transparent to visible light.

[0044] The main body 112A is a rectangular plate-like portion when viewed in the XY plane, and covers the +Z direction side of the substrate 111 on which the array antenna 111A is formed. The substrate 111 is fixed to the surface on the -Z direction side of the main body 112A with, for example, double-sided tape or adhesive. As an example, the four corners of the main body 112A when viewed in the XY plane are chamfered in an arc shape.

[0045] The legs 112B protrude in the -Z direction from the four corners of the main body 112A when viewed in the XY plane. 2 to 5 show two legs 112B located at the +Y and -Y corners of the end of the +X direction of the main body 112A, while the remaining two legs 112B are located at the +Y and -Y corners of the end of the +X direction of the main body 112A.

[0046] The leg portion 112B is L-shaped when viewed in the XY plane. The leg portion 112B is bent in an arc shape between a portion extending in the X direction and a portion extending in the Y direction at portions corresponding to the four corners of the main body portion 112A when viewed in the XY plane.

[0047] The cover 112 is fixed to the window glass 11 by adhering the −Z direction ends of the leg portions 112B at the four corners to the indoor main surface 11A of the window glass 11 with four double-sided tapes 115A1. While Fig. 5 shows two double-sided tapes 115A1 corresponding to the two leg portions 112B on the +X direction side, two double-sided tapes 115A1 are also provided corresponding to the two leg portions 112B on the −X direction side.

[0048] The four legs 112B are adhered to the indoor main surface 11A of the window glass 11 outside the four corners of the rectangular matching layer 115B in the XY plane. In other words, the cover 112 is attached to the window glass 11 so as to straddle the matching layer 115B in the XY plane, without the legs 112B touching the matching layer 115B. The shape and size of the double-sided tape 115A1 in the XY plane are substantially the same as the shape and size of the legs 112B.

[0049] When the cover 112 is fixed to the indoor main surface 11A of the window glass 11 by the four legs 112B, a gap is provided between the main body 112A and the indoor main surface 11A of the window glass 11. The dimension (length) in the Z direction of the legs 112B is greater than the combined dimension in the Z direction of the thickness of the substrate 111 on which the array antenna 111A is formed and the thickness of the matching layer 115B. Therefore, the array antenna 111A is disposed at a gap in the Z direction from the matching layer 115B.

[0050] Main body 112A is attached to window glass 11 by four legs 112B at a distance, and array antenna 111A is provided with a space between it and matching layer 115B. This ensures a space (air layer) through which air can flow between array antenna 111A and matching layer 115B. By ensuring an air layer between array antenna 111A and matching layer 115B, it is possible to prevent a temperature rise in the portion of window glass 11 facing antenna 110 due to a rise in temperature of antenna 110, which can contribute to preventing thermal cracking of window glass 11 due to a difference in thermal expansion coefficient.

[0051] The length of the leg 112B in the Z direction is, for example, preferably 0.5 mm to 100 mm, more preferably 2 mm to 16 mm, even more preferably 4 mm to 14 mm, and particularly preferably 6 mm to 12 mm, in order to ensure an air gap between the array antenna 111A and the matching layer 115B.

[0052] The leg portions 112B are not limited to the shape and number described above as long as they can hold the main body 112A against the window glass 11 while ensuring an air gap between the array antenna 111A and the matching layer 115B. The double-sided tape 115A1 may have a shape and number corresponding to the shape and number of the leg portions 112B. The antenna 110 may be suspended from the drive unit 130 without being attached to the window glass 11.

[0053] <Temperature sensor 113> As an example, the temperature sensor 113 is provided at the end of the -X direction on the surface on the -Z direction side of the substrate 111, and detects the temperature of the array antenna 111A as the temperature of the antenna 110. As an example, an ultra-compact non-contact temperature sensor that measures the temperature of the air in the vicinity of the array antenna 111A as the radiation temperature of the array antenna 111A can be used as the temperature sensor 113. Furthermore, the temperature sensor 113 may detect the temperature of the substrate 111 or the cover 112, etc. as the temperature of the antenna 110.

[0054] The temperature sensor 113 outputs temperature data indicating the detected temperature to the control unit 132 of the driving unit 130. As an example, the temperature sensor 113 and the driving unit 130 are connected via wiring provided along the outer surface of the waveguide 120, and the control unit 132 of the driving unit 130 can acquire the temperature data from the temperature sensor 113. Note that the temperature sensor 113 and the driving unit 130 may be configured so that the temperature data can be transmitted from the temperature sensor 113 to the driving unit 130 via short-range wireless communication such as BLE (registered trademark) instead of via wiring.

[0055] The temperature of the antenna 110 described above increases due to heating by, for example, sunlight passing through the window glass 11. Furthermore, for example, the array antenna 111A generates heat as it transmits and receives radio waves, causing the temperature of the antenna 110 to increase.

[0056] Hereinafter, the portion of the window glass 11 that overlaps with the antenna 110 in the XY plane view and its surrounding area will be referred to as portion A1 (see FIG. 2A) of the window glass 11. The portion of the window glass 11 that overlaps with the antenna 110 in the XY plane view and its surrounding area is the portion of the window glass 11 that faces the antenna 110 and its surrounding area.

[0057] The array antenna 111A is spaced from the window glass 11 by a distance substantially equal to the length of the leg 112B in the Z direction, but heat from the array antenna 111A generated by a temperature rise due to solar radiation or a temperature rise associated with transmission and reception is transmitted to the window glass 11 through the air layer between the array antenna 111A and the matching layer 115B or the window glass 11. As a result, the temperature of the portion A1 of the window glass 11 rises more than the temperature of the portions of the window glass 11 other than portion A1.

[0058] The area of ​​the antenna 110 in the XY plane is 0.004 m 2 ~0.250m 2 It is preferable that the area of ​​portion A1 of the window glass 11 is determined by the area of ​​the antenna 110 in the XY plane, and the area of ​​portion A1 is slightly larger than the area of ​​the antenna 110 in the XY plane. When using heat generated by the drive unit 130 to suppress thermal cracking in the portion of the window glass 11 between portion A1 and the outer edge 11E, a balance between the size of the drive unit 130 and the size of portion A1 reduces the temperature gradient and makes it possible to suppress thermal cracking, so it is preferable that the area of ​​the antenna 110 in the XY plane be within the above-mentioned range. A smaller temperature gradient means a gentler temperature gradient.

[0059] The portion of the window glass 11 between the portion A1 and the outer edge 11E is a portion that has the same width as the portion A1 in the X direction and is located between the portion A1 and the outer edge 11E in the Y direction.

[0060] Furthermore, the length of antenna 110 in the X direction is preferably 0.5 to 2.0 times the length of drive unit 130 in the X direction. The length of antenna 110 in the X direction in relation to the length of drive unit 130 in the X direction is the length in the extension direction (X direction) of outer edge 11E of window glass 11. This is because a certain length of the section sandwiched between antenna 110 and drive unit 130 is ensured in order to reduce the temperature gradient in the portion of window glass 11 between portion A1 and outer edge 11E and thereby suppress thermal cracking.

[0061] The length of antenna 110 in the X direction is preferably 1.5 times or less, more preferably 1.3 times or less, even more preferably 1.0 times or less, and particularly preferably 0.7 times or less, the length of drive unit 130 in the X direction. Within these ranges, the temperature gradient is reduced, and thermal cracking can be further suppressed.

[0062] Furthermore, since there is a section in the extension direction (X direction) of the outer edge 11E where both the antenna 110 and the drive unit 130 are present, heat from the antenna 110 and the drive unit 130 is easily transferred to the section between portion A1 of the window glass 11 and the outer edge 11E, thereby reducing the temperature gradient. This is because there is a section in the X direction of the window glass 11 where two heat sources (the antenna 110 and the drive unit 130) are present together, heat is efficiently transferred to the window glass 11 within that section. The presence of both the antenna 110 and the drive unit 130 means that the sections where the antenna 110 and the drive unit 130 are present overlap in the X direction.

[0063] <Matching layer 115B> The matching layer 115B is provided on the indoor main surface 11A of the window glass 11 on the -Z direction side (radio wave incident side) of the array antenna 111A. The matching layer 115B is fixed to the indoor main surface 11A of the window glass 11 by, for example, double-sided tape 115A2. That is, the matching layer 115B is in surface contact with the main surface 11A of the window glass 11. The double-sided tape 115A2 has approximately the same size as the matching layer 115B when viewed in the XY plane. When viewed in the XY plane, the double-sided tape 115A2 is located inside an imaginary rectangular area connecting the four double-sided tapes 115A1.

[0064] The matching layer 115B is provided to adjust the electrical length of the radio waves incident on the array antenna 111A and match the impedance. The matching layer 115B can be made of polycarbonate, acrylic, COP (cycloolefin polymer), PET (polyethylene terephthalate), polystyrene, glass, or the like.

[0065] <Waveguide 120> Two waveguides 120 are provided between the antenna 110 and the driving unit 130. The two waveguides 120 are arranged parallel to each other with a gap in the X direction and have the same length. The relative positions of the antenna 110 and the driving unit 130 in the X direction are determined by the two waveguides 120. As an example, the waveguides 120 may be configured to guide two types of radio waves (high frequency signals), horizontally polarized and vertically polarized.

[0066] The waveguide 120 has an end 121 (see FIGS. 2, 3, and 4) connected to the array antenna 111A of the antenna 110 and an end 122 (see FIG. 3) connected to the driver 130, and guides radio waves received by the antenna 110. The end 121 is an example of a first end, and the end 122 is an example of a second end. Here, as an example, a configuration in which the wireless communication device 100 includes two waveguides 120 will be described, but the number of waveguides 120 may be one, or three or more. Note that even when there is one waveguide 120, the relative positions of the antenna 110 and the driver 130 do not need to be adjusted in the X direction, and therefore the relative positions of the antenna 110 and the driver 130 in the X direction are determined by the single waveguide 120.

[0067] As described above, it is possible to use an FPC transmission line instead of the waveguide 120. In this case, for example, an RF component such as an amplifier may be mounted on the transparent antenna 110. Furthermore, the relative positions of the antenna 110 and the driver 130 in the X direction are determined by the FPC transmission line.

[0068] Waveguide 120 is, for example, a bendable waveguide that extends from cover 112 of antenna 110 in the +Z direction, is bent in the +Y direction, and extends to the lower end of drive unit 130. Waveguide 120 is almost inelastic, but can be bent at any position between end 121 and end 122. As such a bendable waveguide 120, for example, a flexible waveguide can be used.

[0069] <Drive unit 130> The driving unit 130 is the portion of the antenna 110 and the driving unit 130 that are the main components related to wireless communication of the wireless communication device 100 as a repeater, excluding the antenna 110 that transmits and receives radio waves to and from the outdoor side. The driving unit 130 has the following main functions: to perform beamforming of the antenna 110, to amplify radio waves received by the antenna 110 and radiate them to the outdoor side, to amplify radio waves received from the indoor side and radiate them to the outdoor side from the antenna 110, and to perform adjustment processing to adjust the amplification degree of the radio waves so that the temperature difference between the driving unit 130 and the antenna 110 is 50°C or less.

[0070] The drive unit 130 is fixed by screws 135 to two brackets 140 attached to the indoor surface 12A of the window frame 12. That is, the drive unit 130 is attached to the indoor surface 12A of the window frame 12 by the two screws 135 and the two brackets 140. The screws 135 are an example of a protrusion that protrudes in the X direction from the housing 131 of the drive unit 130. Note that instead of the screws 135, a protrusion that is integrally formed with the housing 131 and protrudes in the X direction may be provided.

[0071] The driving unit 130 has an array antenna 130A, a heat dissipation unit 130B (FIGS. 2, 4, and 5), a housing 131, a control unit 132, and a temperature sensor 133. The temperature sensor 133 is an example of a first temperature sensor, and the temperature detected by the temperature sensor 133 is an example of a first temperature. The array antenna 130A, the heat dissipation unit 130B, the control unit 132, and the temperature sensor 133 are arranged inside the housing 131. The housing 131 is, for example, a rectangular parallelepiped resin case. The housing 131 is fixed to a bracket 140 with screws 135. The array antenna 130A is provided on the +Z direction side within the housing 131, and the heat dissipation unit 130B is provided on the -Z direction side within the housing 131.

[0072] The control unit 132 is connected to the end 122 of the waveguide 120, and performs processes such as amplifying radio waves received from the antenna 110 via the waveguide 120 and outputting the amplified radio waves to the array antenna 130A, and controlling the radiation direction in which the array antenna 130A radiates the radio waves. The control unit 132 also performs processes such as driving control of the array antenna 111A of the antenna 110 and adjusting the amplification degree of the radio waves so that the temperature difference between the driving unit 130 and the antenna 110 is 50°C or less. The process of driving control of the array antenna 111A is a process for performing beamforming with the array antenna 111A.

[0073] In order to perform the above-mentioned processes, the control unit 132 includes an amplifier, a microcomputer, etc. Furthermore, the control unit 132 is connected to the heat dissipation unit 130B in a manner that allows thermal conduction, and dissipates heat via the heat dissipation unit 130B.

[0074] For example, the temperature sensor 133 detects the temperature of the heat dissipation unit 130B as the temperature of the driving unit 130. The temperature sensor 133 outputs to the control unit 132 temperature data indicating the detected temperature.

[0075] The temperature of the drive unit 130 is not limited to the temperature of the heat dissipation unit 130B, but may be, for example, the temperature of a portion of the housing 131 facing the window frame 12, the control unit 132, the bracket 140, the array antenna 130A, or the like. Also, it may be the temperature of a portion of the housing 131 other than the portion facing the window frame 12. In these cases, the temperature sensor 133 may be provided in, for example, the portion of the housing 131 facing the window frame 12, the control unit 132, the bracket 140, the array antenna 130A, or the like to detect the temperature.

[0076] The heat dissipation unit 130B faces the indoor surface 12A of the window frame 12 when the drive unit 130 is attached to the window frame 12 by the bracket 140. Therefore, the heat generated by the control unit 132 can be dissipated from the heat dissipation unit 130B to the window frame 12. A member with high thermal conductivity may be provided between the heat dissipation unit 130B and the window frame 12.

[0077] <Bracket 140> As shown in FIGS. 2 and 3, the brackets 140 are fixed to the indoor surface 12A of the window frame 12 via double-sided tape 145 (see FIG. 5). The brackets 140 are made of resin, metal, or the like. One bracket 140 is provided on each of the +X direction side and the −X direction side of the housing 131 of the drive unit 130, and one bracket 140 is disposed on each side so as to sandwich the ±X direction ends of the drive unit 130. The brackets 140 may also be fixed to the window frame 12 with screws or the like. Fixing with screws is particularly effective when the surface 12A of the window frame 12 is not flat or when the material makes it difficult to fix with the double-sided tape 145.

[0078] The bracket 140 has a flat plate portion 140P, a rib 140R, and a guide groove 141. The guide groove 141 is an example of a guide portion. The flat plate portion 140P is a flat portion that is approximately parallel to the YZ plane. As shown in FIG. 3, the flat plate portion 140P has an approximately trapezoidal shape when viewed in the YZ plane. The flat plate portion 140P is formed with a guide groove 141 that is X-shaped when viewed in the YZ plane. The rib 140R is formed around the flat plate portion 140P that is approximately parallel to the YZ plane and in the vicinity of the guide groove 141 for reinforcement.

[0079] The guide groove 141 is an X-shaped groove that penetrates the flat plate portion 140P in the X direction. The X-shape of the guide groove 141 extends in four directions that form angles of 45 degrees with respect to the Y axis and Z axis when viewed from the YZ plane.

[0080] When installing the wireless communication device 100 in the window 10, placing it indoors in the building 1 (see FIG. 1) makes it easier to protect it from wind, rain, dust, etc., and allows it to operate stably for a long period of time. For this reason, the wireless communication device 100 is placed indoors.

[0081] Furthermore, when the wireless communication device 100 is attached to the window 10, it is preferable that the antenna 110 be provided in a portion that overlaps the window glass 11 in order to efficiently receive radio waves that pass through the window glass 11. For this reason, in one embodiment, as an example, each portion of the antenna 110 is made transparent and the antenna 110 is attached to the window glass 11, thereby realizing efficient reception of radio waves propagating from outside and suppressing obstruction of the view of the window glass 11.

[0082] On the other hand, the amplifier, microcomputer, etc. of the driver 130 generate heat due to amplification processing and control of the array antenna 130A, so if it is attached to the window glass 11, the heat may damage or break the window glass 11. Also, it is difficult to make the driver 130 itself optically transparent. For these reasons, it is more convenient to attach the driver 130 to the window frame 12 or to a wall near the window. In particular, if the window frame 12 is made of metal, it is possible to dissipate the heat generated by the driver 130 via the window frame 12.

[0083] For the reasons described above, in the embodiment, the antenna 110 is attached to the window glass 11, and the drive unit 130 is attached to the window frame 12. Here, as an example, a configuration in which the antenna 110 and the drive unit 130 are attached to the upper side (+Y direction side) of the window glass 11 and the window frame 12 will be described. However, the same applies to a configuration in which the antenna 110 and the drive unit 130 are attached to the lower side (-Y direction side) or side (+X direction side or -X direction side) of the window glass 11 and the window frame 12.

[0084] 3, the window glass 11 and the window frame 12 often have different thicknesses in the Z direction, and there is a step G between the indoor main surface 11A of the window glass 11 and the indoor surface 12A of the window frame 12. The step G can have various dimensions depending on the type of window 10. Depending on the shapes of the window glass 11 and the window frame 12, and the positional relationship in the Y direction between the end of the window glass 11 on the +Y direction side and the window frame 12, it may be necessary to adjust the relative positions in the Y direction when attaching the antenna 110 and the driver 130 to the window glass 11 and the window frame 12, respectively.

[0085] For this reason, the bracket 140 is provided with the guide groove 141 as described above, so that when the antenna 110 and the drive unit 130 are attached to the main surface 11A of the window glass 11 and the surface 12A of the window frame 12, respectively, the relative positions of the antenna 110 and the drive unit 130 in the Y direction and the Z direction can be adjusted.

[0086] <Position of antenna 110 attached to window glass 11 and temperature gradient> Although the antenna 110 has optical transparency, it is less than that of the window glass 11. Therefore, when attaching the antenna 110 to the window glass 11, it is preferable to attach the antenna 110 to the edge of the window glass 11 rather than the center. If the antenna 110 is attached to the center of the window glass 11, visibility will be impaired to some extent. For this reason, the antenna 110 is attached to the window glass 11 near the window frame 12. The distance between the window frame 12 and the antenna 110 is preferably less than 100 mm so as not to obstruct the visibility of the window glass 11. Note that the distance between the window frame 12 and the antenna 110 is the distance in the Y direction when viewed from the XY plane.

[0087] Incidentally, the window frame 12 is made of metal and has a higher heat dissipation property than the window glass 11, so the temperature of the window frame 12 is lower than that of the window glass 11. Particularly in winter or in cold regions, the temperature of the window frame 12 becomes very low, resulting in a large temperature difference between the window frame 12 and the window glass 11. This is the same even if the window frame 12 is made of a material other than metal, such as resin.

[0088] Furthermore, when sunlight is irradiated onto the outdoor-side main surface 11B (see FIG. 3) of the window glass 11, the window glass 11 is heated, and the sunlight that passes through the window glass 11 heats the matching layer 115B and the antenna 110. Furthermore, the temperature of the antenna 110 rises because the array antenna 111A generates heat as it transmits and receives radio waves.

[0089] The substrate 111, array antenna 111A, and main body 112A of the antenna 110 are spaced from the window glass 11 by a distance approximately equal to the Z-direction length of the leg 112B, but heat generated by temperature rise due to solar radiation or temperature rise associated with transmission and reception propagates to the matching layer 115B and the window glass 11 through the air layer between the array antenna 111A and the matching layer 115B or the window glass 11.

[0090] The matching layer 115B is heated by sunlight and by heat propagating from the antenna 110 through the air layer. The heat of the matching layer 115B is propagated to the window glass 11.

[0091] Therefore, the temperature of portion A1 of the window glass 11 rises more than that of portions other than portion A1 of the window glass 11 due to the heat propagating from the antenna 110 through the air layer and the heat propagating from the matching layer 115B.

[0092] As described above, when the temperature of portion A1 of the window glass 11 rises, measures are needed to prevent thermal cracking due to an increased temperature gradient in the portion of the window glass 11 between portion A1 and outer edge 11E, because the distance between portion A1 and outer edge 11E that contacts the window frame 12 on the +Y direction side is short. If the temperature gradient increases in a portion of the window glass 11 with a short distance, such as between portion A1 and outer edge 11E, thermal cracking of the window glass 11 may occur.

[0093] <Prevention of thermal cracking of window glass> The wireless communication device 100 reduces the temperature gradient in the portion of the window glass 11 between the portion A1 and the outer edge 11E by attaching the driver 130 as a heating element to the window frame 12 on the +Y direction side of the portion A1 of the window glass 11. The wireless communication device 100 then adjusts the temperature difference between the driver 130 as a heating element and the antenna 110 to 50°C or less, preferably 40°C or less, and more preferably 20°C or less. In this way, the temperature gradient in the portion of the window glass 11 between the portion A1 and the outer edge 11E is reduced, thereby suppressing thermal cracking of the window glass 11.

[0094] More specifically, the control unit 132 performs an adjustment process to adjust the amplification degree of the radio waves in the driving unit 130 based on the temperatures detected by the temperature sensors 113 and 133, thereby adjusting the temperature difference between the driving unit 130 and the antenna 110 to 50°C or less, 40°C or less, or 20°C or less.

[0095] 7 is a block diagram showing an example of the configuration of control unit 132 and temperature sensors 113 and 133. Control unit 132 is connected to temperature sensors 113 and 133, and includes a built-in memory 132A. Memory 132A is an example of a storage unit.

[0096] As described above, thermal cracking occurs when the temperature gradient of the window glass 11 increases, causing a local difference in the thermal expansion coefficient, and increasing the stress acting on the window glass 11. For this reason, as an example, if the relationship between the stress acting on the portion of the window glass 11 between portion A1 and the outer edge 11E and the temperature difference between the driver 130 and the antenna 110 is understood, thermal cracking of the window glass 11 can be suppressed by adjusting the temperature difference to be smaller.

[0097] Here, we will explain the case where the relationship between stress and temperature difference is used. However, since stress can be expressed as a temperature gradient or a difference in thermal expansion coefficient, the relationship between the temperature gradient and the temperature difference, or the relationship between the difference in thermal expansion coefficient and the temperature difference, may be used to adjust the temperature difference to be smaller.

[0098] When using the relationship between stress and temperature difference, data that represents the relationship between the stress in the portion of the window glass 11 between portion A1 and the outer edge 11E and the temperature difference between the driver 130 and the antenna 110 is obtained in advance through experiments or simulations. In addition, an upper limit of the range of stress that will not cause thermal cracking of the window glass 11 is calculated. The upper limit of the range that will not cause thermal cracking is the upper limit of stress that will not cause thermal cracking both when the temperature of the driver 130 is higher than the temperature of the antenna 110 and when the temperature of the driver 130 is lower than the temperature of the antenna 110.

[0099] The memory 132A may store temperature difference data that indicates the temperature difference between the drive unit 130 and the antenna 110 corresponding to a value obtained by subtracting a predetermined margin from the upper limit of the stress range that will not cause thermal cracking of the window glass 11. As an example, the temperature difference data is data that indicates a temperature difference of 50°C between the drive unit 130 and the antenna 110.

[0100] Then, the control unit 132 calculates the temperature difference between the driving unit 130 and the antenna 110 based on the temperatures detected by the temperature sensors 113 and 133, and performs an adjustment process to adjust the amplification of the radio waves in the driving unit 130 so that the calculated temperature difference is equal to or less than the temperature difference (50°C) represented by the temperature difference data stored in the memory 132A.

[0101] Specifically, when the temperature of the driver 130 is higher than the temperature of the antenna 110, and the calculated temperature difference reaches the temperature difference (50°C) represented by the temperature difference data, an adjustment process may be performed to reduce the amplification of the radio waves in the driver 130, for example. To reduce the amplification of the radio waves in the driver 130, the current used by the driver 130 to amplify the radio waves may be reduced. Reducing the current reduces the temperature of the driver 130, thereby reducing the temperature difference between the driver 130 and the antenna 110 and reducing the stress in the portion of the window glass 11 between portion A1 and the outer edge 11E.

[0102] Furthermore, when the temperature of the driver 130 is lower than the temperature of the antenna 110, and the calculated temperature difference reaches the temperature difference (50°C) represented by the temperature difference data, an adjustment process may be performed to increase the amplification of the radio waves in the driver 130, for example. To increase the amplification of the radio waves in the driver 130, the current used by the driver 130 to amplify the radio waves may be increased. Increasing the current increases the temperature of the driver 130, thereby reducing the temperature difference between the driver 130 and the antenna 110 and reducing the stress in the portion of the window glass 11 between portion A1 and the outer edge 11E.

[0103] As an example, if the temperature difference represented by the temperature difference data is 50°C, the control unit 132 performs adjustment processing so that the temperature difference between the driving unit 130 and the antenna 110 is 50°C or less. If the temperature difference represented by the temperature difference data is 40°C, the control unit 132 performs adjustment processing so that the temperature difference between the driving unit 130 and the antenna 110 is 40°C or less. If the temperature difference represented by the temperature difference data is 20°C, the control unit 132 performs adjustment processing so that the temperature difference between the driving unit 130 and the antenna 110 is 20°C or less.

[0104] As mentioned above, the distance between the window frame 12 and the antenna 110 is preferably less than 100 mm so as not to obstruct the view through the window glass 11, but having the window frame 12 and the antenna 110 close to each other also provides the following effect: The wireless communication device 100 has the driving unit 130, which serves as a heating element, fixed to the window frame 12 in contact with the outer edge 11E of the window glass 11. Therefore, the closer the window frame 12 and the antenna 110 are to each other, the closer the portion A1 of the window glass 11 to the outer edge 11E becomes, and a low-temperature portion is less likely to occur between the portion A1 and the outer edge 11E, thereby reducing stress.

[0105] <Simulation (Part 1)> A simulation (part 1) was performed to calculate the temperature gradient and stress distribution occurring in the window glass 11. In the simulation, the parameters of each part were set as shown in Fig. 8. Fig. 8 is a diagram showing an example of the parameters used in the simulation.

[0106] Figure 8 shows the simulation parameters, such as solar radiation intensity (W / m 2 ), indoor glass surface temperature (℃), outdoor glass surface temperature (℃), thermal conductivity of the matching layer (W / m / K), antenna thickness (mm), antenna surface heat dissipation (W / m 2 / K), and the thermal conductivity of the antenna (W / m / K). Figure 8 also shows the thickness of the air layer (mm), the thickness of the matching layer (mm), the reflectance of the matching layer, the solar transmittance of the matching layer, the solar transmittance of the antenna, the reflectance of the antenna, the distance between the window frame and the antenna (mm), and the area of ​​the antenna (m 2), the temperature of the driver (°C), the width of the driver (mm), and the heat capacity of the PA / LNA (W). In the simulation, the temperature of the antenna 110 was calculated based on the solar radiation intensity, the solar transmittance of the antenna, and the size of the antenna, and the stress generated in the window glass 11 was calculated based on the temperature of the antenna 110.

[0107] Solar radiation intensity (W / m 2 ) is the intensity of solar radiation incident on the window glass 11, and solar radiation is the sum of direct solar radiation, sky solar radiation, and ground-reflected solar radiation. The indoor glass surface temperature (°C) is the temperature of the indoor main surface 11A of the window glass 11, and the outdoor glass surface temperature (°C) is the temperature of the outdoor main surface 11B of the window glass 11.

[0108] The thermal conductivity of the matching layer (W / m / K) is the thermal conductivity of the matching layer 115B. The thickness of the antenna (mm) is the thickness of the cover 112 of the antenna 110 in the Z direction. The surface heat dissipation of the antenna (W / m 2 / K) is the amount of heat dissipated from the surface on the −Z direction side of the antenna 110. The thermal conductivity of the antenna (W / m / K) is the thermal conductivity of the entire antenna 110.

[0109] The thickness of the air layer (mm) is the thickness of the air layer existing between the surface on the -Z side of the array antenna 111A and the surface on the +Z side of the matching layer 115B, and is equal to the distance between the surface on the -Z side of the array antenna 111A and the surface on the +Z side of the matching layer 115B.

[0110] The thickness (mm) of the matching layer is the thickness of the matching layer 115B in the Z direction. The reflectance of the matching layer is the reflectance of the matching layer 115B. The solar transmittance of the matching layer is the solar transmittance of the matching layer 115B. Here, the solar transmittance is, for example, the solar transmittance specified in ISO9050:2003.

[0111] The solar transmittance of the antenna is the solar transmittance of the antenna 110, and the solar transmittance is, for example, the solar transmittance specified in ISO9050:2003. The reflectance of the antenna is the reflectance of the antenna 110. The distance (mm) between the window frame and the antenna is the distance in the Y direction between the window frame 12 on the +Y direction side and the end of the cover 112 of the antenna 110 on the +Y direction side. The area of ​​the antenna (m 2 ) is the area of ​​the cover 112 of the antenna 110 as viewed in the XY plane.

[0112] The temperature (°C) of the driver is the temperature (°C) of the control unit 132 of the driver 130, and corresponds to the temperature detected by the temperature sensor 133. The width (mm) of the driver is the width of the driver 130 in the X direction. The PA / LNA heat amount (W) is the heat amount of the PA (Power Amplifier) ​​for transmission included in the control unit 132 and the heat amount of the LNA (Low Noise Amplifier) ​​for reception included in the control unit 132.

[0113] Of the above parameters, the solar radiation intensity and the reflectance of the matching layer were set to fixed values, and the solar radiation transmittance of the matching layer and the PA / LNA heat quantity were set to values ​​within the ranges shown in Figure 8.

[0114] Among the parameters shown in Figure 8, the representative parameter values ​​are as follows: Solar radiation intensity is 850 (W / m 2 ), which means that the solar radiation is very strong. The indoor glass surface temperature is 20°C and the outdoor glass surface temperature is -15°C, which means that it is midwinter and the heating is on indoors. The solar transmittance of matching layer 115B is 0.75 (75%) to 0.9 (90%) as specified in ISO9050:2003. The solar transmittance of antenna 110 is 0.4 (40%) to 0.8 (80%) as specified in ISO9050:2003. The total heat dissipation of the PA / LNA is 5W, but the simulation was performed by changing the ratio of the heat dissipation of the PA to the LNA.

[0115] <Temperature distribution> FIG. 9 is a diagram showing an example of a temperature distribution obtained by simulation. FIG. 9 shows the temperature distribution in the window glass 11, window frame 12, and drive unit 130 in an XY plane view. In FIG. 9, the inner and outer edges of the window frame 12 are indicated by dashed lines. The window glass 11 does not extend into the window frame 12, and the outer edge 11E of the window glass 11 coincides with the inner edge (inner dashed line) of the window frame 12. In FIG. 9, the portion of the window glass 11 that overlaps with the antenna 110 in an XY plane view and a surrounding portion A1, as well as the drive unit 130, are indicated by dashed lines. In the simulation, the drive unit 130 is provided in the center of the portion of the window frame 12 that contacts the outer edge 11E.

[0116] For this reason, the simulation will describe the stress in the portion between portion A1 and the central portion in the X direction of outer edge 11E of window glass 11. The portion between portion A1 and the central portion in the X direction of outer edge 11E of window glass 11 is a portion that has the same width in the X direction as portion A1 and is located between portion A1 and outer edge 11E in the Y direction.

[0117] 9, the temperature of the drive unit 130 is the highest in the window frame 12, and the parts of the window frame 12 on the +X direction side and the -X direction side of the drive unit 130 are hotter than other parts of the window frame 12, confirming that the heat of the drive unit 130 is being propagated. It was also confirmed that the part of the window glass 11 on the -Y direction side of the drive unit 130 also has a part where the temperature rises due to the heat from the drive unit 130 being propagated.

[0118] It was also confirmed that the temperature of portion A1 was lower than that of the drive unit 130, but higher than that of the portion of the window glass 11 outside portion A1. Since the simulation was conducted in the middle of winter and the temperature of the window frame 12 was very low, it was confirmed that in the portion of the window frame 12 where the drive unit 130 was not located, there was a large temperature difference between the window frame 12 and the window glass 11. It was also confirmed that, between the drive unit 130 and portion A1, the temperature of the portion of the window glass 11 on the -Y direction side of the drive unit 130 was higher.

[0119] <Stress distribution> 10A and 10B are diagrams showing examples of simulation results of stress distribution. Fig. 10A shows the stress distribution obtained as a simulation result for a comparative wireless communication device under simulation conditions in which the driving unit 130 is omitted from the simulation conditions under which the temperature distribution obtained in Fig. 9 was obtained. Fig. 10A does not show the stress distribution in the window frame 12, but shows the stress distribution only in the window glass 11.

[0120] Fig. 10B shows the stress distribution in the window glass 11 under the simulation conditions of the wireless communication device 100 under which the temperature distribution shown in Fig. 9 was obtained. Fig. 10B does not show the stress distribution in the window frame 12, but shows the stress distribution only in the window glass 11. The central part of the outer edge 11E in the X direction is the part of the outer edge 11E on the -Y direction side of the drive unit 130.

[0121] 10A, the stress between the central portion of outer edge 11E in the X direction and portion A1 falls into five ranges: 6.8795 (MPa) to 8.6237 (MPa), 8.6237 (MPa) to 10.368 (MPa), 10.368 (MPa) to 12.112 (MPa), 12.112 (MPa) to 13.856 (MPa), and 13.856 (MPa) to 15.601 (MPa). The highest stress range, 13.856 (MPa) to 15.601 (MPa), is located in the central portion of outer edge 11E in the X direction.

[0122] 10A , the pressures in the X-direction of the outer edge 11E other than between the central portion and portion A1 were as follows: Within portion A1, from the −Y direction to the +Y direction, there were ranges of 1.6469 (MPa) to 3.3911 (MPa), 3.3911 (MPa) to 5.1353 (MPa), 5.1353 (MPa) to 6.8795 (MPa), and 6.8795 (MPa) to 8.6237 (MPa). Below portion A1 in the Y direction, from the −Y direction to the +Y direction, there were ranges of −0.097351 to 1.6469 (MPa) and 1.6469 (MPa) to 3.3911 (MPa). The width of each range in the Y direction was wider. Furthermore, on the −Y direction side of the center of the window glass 11 in the Y direction, the modulus was in the range of −0.097351 (MPa) to 1.6469 (MPa) over the entire area.

[0123] 10A, it can be seen that in the comparative wireless communication device, the greatest change in stress occurs between the central part of outer edge 11E in the X direction and part A1, which indicates that the temperature gradient is large due to the lack of heat propagation from drive unit 130.

[0124] Furthermore, for wireless communication device 100, as shown in FIG. 10B, only the range of 3.3911 (MPa) to 5.1353 (MPa) existed between the central portion of outer edge 11E in the X direction and portion A1.

[0125] 10B, the pressure in the X direction of the outer edge 11E other than between the center and the portion A1 was in the range of −0.097351 (MPa) to 1.6469 (MPa) or 1.6469 (MPa) to 3.3911 (MPa). Within the portion A1, the pressure range was 1.6469 (MPa) to 3.3911 (MPa).

[0126] As described above, it has been confirmed that the stress range between the central portion of outer edge 11E in the X direction and portion A1 shown in Fig. 10B is only 3.3911 (MPa) to 5.1353 (MPa), which is significantly reduced compared to the stress distribution between the central portion of outer edge 11E in the X direction and portion A1 shown in Fig. 10A. In other words, it has been confirmed that wireless communication device 100 can suppress thermal cracking of window glass 11.

[0127] 10A and the stress distribution of wireless communication device 100 shown in Fig. 10B were similar on the -Y direction side of the center in the Y direction of window glass 11, but it was confirmed that the stress distribution of wireless communication device 100 shown in Fig. 10B was more relaxed in the portion other than between the central portion in the X direction of outer edge 11E and portion A1 on the +Y direction side of the center in the Y direction of window glass 11. It is believed that the temperature gradient was also relaxed in the portion other than between the central portion in the X direction of outer edge 11E and portion A1 due to heat propagating from drive unit 130.

[0128] <Simulation (Part 2)> Fig. 11 is a diagram showing an example of the results of a simulation (part 2) that calculates stress due to the temperature difference between the driver 130 and the antenna 110. In Fig. 11, the horizontal axis represents the temperature difference between the driver 130 and the antenna 110, and the vertical axis represents the maximum stress between the central portion of the outer edge 11E in the X direction and portion A1. The results indicated by the numerous markers in Fig. 11 are results obtained from a simulation in which the solar transmittance of the matching layer and the value of the PA / LNA heat quantity, among the parameters shown in Fig. 8, were set to various values.

[0129] When the temperature difference was 50°C or less, the stress did not exceed 15 MPa, but when the temperature difference exceeded 50°C, the stress exceeded 15 MPa. In addition to the simulation (Part 2), a simulation was also performed to determine the stress at which thermal cracking occurs in the window glass 11. It was found that thermal cracking occurs in the window glass 11 when the stress exceeds 17 MPa. For this reason, Figure 11 shows a dashed line indicating the stress level of 17 MPa. 17 MPa is known as the short-term allowable stress value for glass sheets.

[0130] It can be seen that stress exceeding 17 (MPa) occurs when the temperature difference exceeds 50°C. For this reason, the wireless communication device 100 is adjusted so that the temperature difference between the driving unit 130 and the antenna 110 is 50°C or less. In all simulation models where the temperature difference is 50°C or less, the stress is 15 (MPa) or less, which makes it possible to suppress thermal damage to the window glass 11.

[0131] 11, when the temperature difference is 40° C. or less, it can be seen that there are more results with low stress than when the temperature difference is between 40° C. and 50° C. For this reason, it can be said that it is more preferable to adjust the temperature difference between the driving unit 130 and the antenna 110 to 40° C. or less.

[0132] 11, when the temperature difference is 20° C. or less, it can be seen that there are more results with low stress than when the temperature difference is between 20° C. and 50° C. Therefore, it can be said that it is more preferable to adjust the temperature difference between the driving unit 130 and the antenna 110 to 20° C. or less.

[0133] 11, it was confirmed that there is a correlation between the temperature difference between the driving unit 130 and the antenna 110 and the stress, and that by keeping the temperature difference at 50°C or less, the maximum value of the stress can be prevented from exceeding 17 (MPa). Therefore, it was confirmed that thermal cracking can be suppressed by storing the above-mentioned temperature difference data in memory 132A and using it in the adjustment process. The temperature difference data indicates that the temperature difference between the driving unit 130 and the antenna 110 is 50°C.

[0134] In the simulations (parts 1 and 2), the conditions were set so that matching layer 115B had a solar transmittance of 0.75 (75%) to 0.9 (90%) as specified in ISO 9050:2003, and antenna 110 had a solar transmittance of 0.4 (40%) to 0.8 (80%) as specified in ISO 9050:2003. However, in an actual wireless communication device 100, matching layer 115B only needs to have a solar transmittance of 0.75 (75%) or more as specified in ISO 9050:2003, and antenna 110 only needs to have a solar transmittance of 0.4 (40%) as specified in ISO 9050:2003.

[0135] <Transparent conductor 300 realizing array antenna 111A> Fig. 12 is a diagram showing an example of the configuration of a transparent conductor 300. The array antenna 111A can be realized, for example, by the transparent conductor 300 shown in Fig. 12. For example, the transparent conductor 300 has a configuration in which mesh-like thin metal wires 310B are provided inside thin metal wires 310A provided along the outer edge. The outer edge is the outer edge and represents the contour.

[0136] The transparent conductor 300 shown in Fig. 12 is a conductor with such high optical transparency that it is difficult for the human eye to see, and is composed of a mesh-like layer of thin metal wires. As an example, the thin metal wires 310A and 310B can be realized by such a transparent conductor 300. The transparent conductor 300 is formed on the surface 111S on the -Z direction side of the substrate 111, and is formed in a mesh shape to increase optical transparency. Here, "mesh" refers to a state in which the transparent conductor 300 has a network of through-holes 301.

[0137] The mesh openings (openings of the through-holes 301) of the transparent conductor 300 may be rectangular or rhombic. When the mesh openings are formed in a rectangular shape, square openings are preferable, as this provides a good design. The through-holes 301 may have portions adjacent to the thin metal wires 310A that are not rectangular but have triangular or other shapes. The mesh openings may also have a random shape formed by a self-organization method, which can suppress moire. The mesh line widths w1, w2, and w3 are preferably 0.5 μm to 5 μm. The mesh line spacing (pitch) p1 and p2 are preferably 10 μm to 500 μm. Here, as an example, the mesh line widths w1, w2, and w3 are 3 μm, and the pitches p1 and p2 are 200 μm. The line widths of the thin metal wires 310A and 310B are, for example, equal.

[0138] The aperture ratio of the transparent conductor 300 is preferably 80% or more, and more preferably 90% or more. The aperture ratio is the ratio of the area of ​​the openings (through holes 301) to the area including the openings of the transparent conductor 300. The greater the aperture ratio of the transparent conductor 300, the higher the luminous transmittance of the transparent conductor 300 can be.

[0139] The thickness of the transparent conductor 300 may be 0.1 μm to 40 μm. By forming the transparent conductor 300 in a mesh shape, the luminous transmittance can be increased even if the transparent conductor 300 is thick. The thickness of the transparent conductor 300 is more preferably 1 μm to 10 μm. Here, as an example, the thickness of the mesh is set to 2 μm.

[0140] The conductive material of the transparent conductor 300 is copper, but other materials such as gold, silver, platinum, aluminum, and chromium can also be used, and the material is not limited to these.

[0141] <Effects> The wireless communication device 100 includes a heating element (drive unit 130) provided on the window frame 12 in contact with the outer edge 11E of the window glass 11, and an antenna 110 provided on the window glass 11, and adjusts the temperature difference between the heating element (drive unit 130) and the antenna 110 to be 50°C or less. This reduces the temperature gradient between portion A1 of the window glass 11 and the outer edge 11E.

[0142] Therefore, it is possible to provide a wireless communication device 100 that can prevent thermal cracking of the window glass 11 (glass plate).

[0143] Furthermore, the distance between the window frame 12 and the antenna 110 is less than 100 mm. With this configuration, it is difficult for a low-temperature area to occur between the portion A1 and the outer edge 11E, thereby reducing the temperature gradient.

[0144] The area of ​​the antenna 110 is 0.004 m 2 ~0.250m 2 A balance between the size of drive unit 130 and the size of portion A1 reduces the temperature gradient, making the temperature gradient between portion A1 and outer edge 11E gentler, thereby making it possible to provide wireless communication device 100 that can further suppress thermal cracking of window glass 11 (glass plate).

[0145] Furthermore, the length in the extension direction (X direction) of outer edge 11E of antenna 110 is 0.5 to 2.0 times the extension direction (X direction) of outer edge 11E of the heating element (drive unit 130). This allows a certain degree of length in the X direction of the section sandwiched between antenna 110 and drive unit 130, and reduces the temperature gradient in the portion of window glass 11 between portion A1 and outer edge 11E. This configuration makes it possible to provide wireless communication device 100 that can further suppress thermal cracking of window glass 11 (glass plate).

[0146] Additionally, there is a section in the direction in which the outer edge 11E extends (X direction) where both the antenna 110 and the heat generating element (drive unit 130) are present. By having a section in the X direction of the window glass 11 where two heat sources (antenna 110 and drive unit 130) are present together, heat is efficiently conducted to the window glass 11 within that section, reducing the temperature gradient. With this configuration, it is possible to provide a wireless communication device 100 that can further suppress thermal cracking of the window glass 11 (glass plate).

[0147] Furthermore, driving unit 130 has temperature sensor 133 (first temperature sensor), and antenna 110 has temperature sensor 113 (second temperature sensor), and the amount of heat generated by driving unit 130 is adjusted so that the temperature difference between the temperature (first temperature) detected by temperature sensor 133 and the temperature (second temperature) detected by temperature sensor 113 is 50°C or less. Therefore, the temperature difference detected by temperature sensors 113 and 133 can be used to more accurately adjust the temperature difference to 50°C or less. By measuring the temperature difference using temperature sensors 113 and 133, it is possible to provide wireless communication device 100 that can suppress thermal cracking of window glass 11 (glass plate) with high accuracy.

[0148] The device further includes memory 132A (storage unit) for storing temperature difference data relating to the temperature difference between drive unit 130 and antenna 110 when thermal cracking occurs in window glass 11. The temperature difference data indicates that the temperature difference between drive unit 130 and antenna 110 is 50°C, and the amount of heat generated by drive unit 130 is adjusted so that the temperature difference detected by temperature sensors 113 and 133 is equal to or less than 50°C indicated by the temperature difference data. Therefore, using the temperature difference data, it is possible to more accurately adjust the temperature difference to be equal to or less than 50°C. By measuring the temperature difference using temperature sensors 113 and 133, it is possible to provide a wireless communication device 100 that can suppress thermal cracking of window glass 11 (glass plate) with high accuracy.

[0149] Furthermore, since the heating element (drive unit 130) is the drive unit 130 of a repeater that relays radio waves received by the antenna 110, the heat generated by the drive unit 130 can be used to increase the temperature of the outer edge 11E side of the window glass 11, thereby reducing the temperature gradient between portion A1 of the window glass 11 and the outer edge 11E. With this configuration, it is possible to provide a wireless communication device 100 that can further suppress thermal cracking of the window glass 11 (glass plate) by utilizing the heat generated by the drive unit 130.

[0150] Furthermore, since the matching layer 115B provided between the window glass 11 and the antenna 110 is further included, it is possible to adjust the electrical length of the radio waves incident on the array antenna 111A to match the impedance, thereby improving the reception efficiency of the antenna 110. With this configuration, it is possible to provide a wireless communication device 100 that can improve the reception efficiency of the antenna 110 and also suppress thermal cracking of the window glass 11 (glass plate).

[0151] Furthermore, matching layer 115B is in surface contact with window glass 11, and is provided with a gap between antenna 110. By providing a gap between antenna 110 and matching layer 115B, an air layer can be secured, which can prevent a temperature rise in the portion of window glass 11 facing antenna 110 due to a rise in temperature of antenna 110, and can prevent thermal cracking of window glass 11 due to a difference in thermal expansion coefficient.

[0152] Furthermore, the antenna 110 is formed of a metal mesh (transparent conductor 300). By forming the antenna 110 from the transparent conductor 300 with high luminous transmittance, it is possible to provide a wireless communication device 100 that is less likely to impair visibility through the window glass 11 and that can suppress thermal cracking of the window glass 11 (glass plate).

[0153] Furthermore, antenna 110 has a solar transmittance of 40% or more as specified by ISO9050:2003. By preventing the temperature of antenna 110 from rising, it is possible to suppress a temperature rise in window glass 11, and by suppressing an increase in the temperature difference between the heating element (drive unit 130) and antenna 110, it is possible to provide wireless communication device 100 that can suppress thermal cracking of window glass 11 (glass plate).

[0154] Matching layer 115B has a solar transmittance of 75% or more as specified by ISO 9050: 2003. By preventing the temperature of matching layer 115B from rising, it is possible to suppress a temperature rise in window glass 11, and by suppressing an increase in the temperature difference between the heating element (drive unit 130) and antenna 110, it is possible to provide wireless communication device 100 that can suppress thermal cracking of window glass 11 (glass plate).

[0155] The above describes an embodiment in which the antenna 110 includes the temperature sensor 113, the driver 130 includes the temperature sensor 133, and the controller 132 performs an adjustment process to adjust the amplification of radio waves based on temperatures detected by the temperature sensors 113 and 133. However, the wireless communication device 100 does not need to include the temperature sensors 113 and 133. For example, antenna temperature data representing the relationship between the amount of solar radiation and the temperature of the antenna 110 and repeater temperature data representing the average temperature of the driver 130 over a year may be stored in advance in the memory of the controller 132. Then, the controller 132 may perform an adjustment process to adjust the amplification of radio waves using the temperature of the antenna 110 obtained from the antenna temperature data using the amount of solar radiation measured by a photoelectric sensor provided on the antenna 110 and the temperature of the driver 130 obtained from the repeater temperature data using the calendar.

[0156] <Modification> 13 is a diagram showing an example of the configuration of a wireless communication device 100M according to a modification of the embodiment. Here, differences between the wireless communication device 100M and the wireless communication device 100 will be described.

[0157] The wireless communication device 100M has a configuration in which a fan 150 is added to the wireless communication device 100 (see FIGS. 1 to 6). The fan 150 is fixed to the housing 131 of the drive unit 130 via a stay 151.

[0158] The fan 150 is provided to cool the drive unit 130. As an example, the fan 150 is disposed on the +Z direction side of the housing 131, and is driven by an electric motor to blow air in the -Z direction.

[0159] For example, when the temperature of the drive unit 130 is higher than the temperature of the antenna 110, and the calculated temperature difference reaches the temperature difference (50°C) represented by the temperature difference data, the control unit 132 drives the fan 150 to send air, thereby lowering the temperature of the drive unit 130. As a result, the temperature difference between the drive unit 130 and the antenna 110 becomes smaller, and the temperature gradient in the portion of the window glass 11 between portion A1 and the outer edge 11E becomes smaller.

[0160] If the fan 150 is driven when the temperature of the drive unit 130 is higher than the temperature of the antenna 110, the temperature of the drive unit 130 can be reduced without performing an adjustment process to reduce the current used by the drive unit 130 to amplify radio waves. Therefore, the reach of the radio waves radiated from the array antenna 130A of the wireless communication device 100M remains the same as the state before the fan 150 was driven.

[0161] The control unit 132 may perform both an adjustment process to reduce the current used by the drive unit 130 to amplify radio waves and a drive process to drive the fan 150.

[0162] Furthermore, since it is sufficient for the fan 150 to cool the drive unit 130, it may be attached to a part other than the housing 131, such as the bracket 140, via the stay 151. It may also be fixed by a fixture other than the stay 151.

[0163] Furthermore, although the above describes a configuration in which fan 150 is provided to cool drive unit 130, fan 150 may also be attached to antenna 110 and configured to lower the temperature of antenna 110 by blowing air.

[0164] In this case, when the temperature of antenna 110 is higher than the temperature of drive unit 130, when the calculated temperature difference reaches the temperature difference (50°C) represented by the temperature difference data, control unit 132 drives fan 150 to send air, thereby lowering the temperature of antenna 110. As a result, the temperature difference between drive unit 130 and antenna 110 becomes smaller, and the temperature gradient in the portion of window glass 11 between portion A1 and outer edge 11E becomes smaller.

[0165] The fan 150 may be attached to both the driving unit 130 and the antenna 110, and may blow air when lowering the temperature of the driving unit 130 or the antenna 110.

[0166] Although exemplary wireless communication devices of the present disclosure have been described above, the present disclosure is not limited to the specifically disclosed embodiments, and various modifications and variations are possible without departing from the scope of the claims.

[0167] The following additional notes are provided regarding the above-described embodiments. (Appendix 1) a heating element provided on a structural part in contact with an edge of the glass sheet; an antenna provided on the glass plate; Including, A wireless communication device that adjusts the temperature difference between the heating element and the antenna to be 50°C or less. (Appendix 2) 2. The wireless communication device of claim 1, wherein the distance between the structure and the antenna is less than 100 mm. (Appendix 3) The area of ​​the antenna is 0.004 m 2 ~0.250m 2 3. The wireless communication device according to claim 1, wherein: (Appendix 4) 4. The wireless communication device according to claim 1, wherein the length of the antenna in the direction in which the end portion extends is 0.5 to 2.0 times the length of the heating element in the direction in which the end portion extends. (Appendix 5) 5. The wireless communication device according to claim 1, wherein the end portion has a section in which both the antenna and the heating element are present in the extending direction. (Appendix 6) the heating element has a first temperature sensor; the antenna has a second temperature sensor; A wireless communication device described in any one of appendix 1 to 5, wherein the heat generation amount of the heating element or the antenna is adjusted so that the temperature difference between the first temperature detected by the first temperature sensor and the second temperature detected by the second temperature sensor is 50°C or less. (Appendix 7) a storage unit for storing temperature difference data relating to a temperature difference between the heating element and the antenna when thermal cracking occurs in the glass plate; the temperature difference data indicates that the temperature difference between the heating element and the antenna is 50°C; 7. The wireless communication device according to claim 6, wherein the heat generation amount of the heating element or the antenna is adjusted so that the temperature difference between the first temperature and the second temperature is equal to or less than 50°C represented by the temperature difference data. (Appendix 8) 8. The wireless communication device according to claim 1, wherein the heating element is a drive unit of a repeater that repeats radio waves received by the antenna. (Appendix 9) 9. The wireless communication device of claim 1, further comprising a matching layer provided between the glass plate and the antenna. (Appendix 10) 10. The wireless communication device of claim 9, wherein the matching layer is in surface contact with the glass plate and spaced apart from the antenna. (Appendix 11) 11. The wireless communication device according to claim 1, wherein the antenna is formed of a metal mesh. (Appendix 12) 12. The wireless communication device according to any one of claims 1 to 11, wherein the antenna has a solar transmittance of 40% or more as specified in ISO9050:2003. (Appendix 13) 11. The wireless communication device according to claim 9, wherein the matching layer has a solar transmittance of 75% or more as specified in ISO9050:2003. [Explanation of symbols]

[0168] 10. Windows 11 Window glass (example of glass plate) 11A, 11B main surface 11E Outer edge (example of edge of glass plate) 12 Window frame (an example of a structural part that contacts the edge of a glass plate) 12A surface 100, 100M wireless communication equipment 110 Antenna 111 Substrate 111A Array Antenna 112 Cover 113 Temperature Sensor 115B Matching layer 120 Waveguide 130 Drive unit (example of heating element) 131 Case 132 Control Unit 132A Memory (Example of storage section) 133 Temperature Sensor 140 Bracket 150 fans 300 Transparent Conductor

Claims

1. a heating element provided on a structural part in contact with an edge of the glass sheet; an antenna provided on the glass plate; Including, A wireless communication device that adjusts the temperature difference between the heating element and the antenna to be 50°C or less.

2. The wireless communication device according to claim 1 , wherein the distance between the structure and the antenna is less than 100 mm.

3. The area of ​​the antenna is 0.004 m ２ ~0.250m ２ The wireless communication device according to claim 1 ,

4. 2. The wireless communication device according to claim 1, wherein the length of said antenna in the direction in which said end portion extends is 0.5 to 2.0 times the length of said heating element in the direction in which said end portion extends.

5. The wireless communication device according to claim 1 , wherein the end portion has a section in an extending direction thereof in which the antenna and the heating element are both present.

6. The heating element has a first temperature sensor, the antenna has a second temperature sensor; 6. The wireless communication device according to claim 1, wherein the heat generation amount of the heating element or the antenna is adjusted so that the temperature difference between the first temperature detected by the first temperature sensor and the second temperature detected by the second temperature sensor is 50°C or less.

7. a storage unit for storing temperature difference data relating to a temperature difference between the heating element and the antenna when thermal cracking occurs in the glass plate; the temperature difference data indicates that the temperature difference between the heating element and the antenna is 50°C; The wireless communication device according to claim 6 , wherein the heat generation amount of the heating element or the antenna is adjusted so that the temperature difference between the first temperature and the second temperature is equal to or less than 50° C., as indicated by the temperature difference data.

8. The wireless communication device according to claim 1 , wherein the heating element is a drive unit of a repeater that repeats radio waves received by the antenna.

9. The wireless communication device of claim 1 , further comprising a matching layer disposed between the glass plate and the antenna.

10. The wireless communication device according to claim 9 , wherein the matching layer is in surface contact with the glass plate and is spaced apart from the antenna.

11. The wireless communication device according to claim 1 , wherein the antenna is formed of a metal mesh.

12. The wireless communication device according to claim 1 , wherein the antenna has a solar transmittance of 40% or more as specified in ISO 9050:2003.

13. The wireless communication device according to claim 9 , wherein the matching layer has a solar transmittance of 75% or more as specified in ISO 9050:2003.

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