Antenna device and wireless communication device

Abstract

Provided are: an antenna device that can be kept from falling by means of a simple structure; and a wireless communication device.　An antenna device according to the present invention includes a flexible spacer that is adhered to a principal surface of window glass by means of an adhesive, an antenna that is disposed opposite the principal surface of the window glass, and a holding member that is attached to the spacer and holds the antenna.

Description

Antenna device and wireless communication device

[0001] The present disclosure relates to an antenna device and a wireless communication device.

[0002] A conventional glass window with a functional component includes a glass window that is erected on a floor and has a glass plate, and a functional component that has an area smaller than the glass plate and is positioned above the floor. The functional component is attached to the glass plate via a spacer and is joined to the spacer via a fastener that is fixed to one end of a wire that is fixed to a window frame. The wire is provided to prevent the spacer from falling if the spacer attached to the glass plate becomes detached from the glass plate (see, for example, Patent Document 1).

[0003] International Publication No. 2019 / 230546

[0004] However, the inclusion of wires for preventing the device from falling would complicate the structure, but if the adhesiveness to the glass plate were improved, a simple structure without using wires could be achieved.

[0005] Therefore, an object of the present invention is to provide an antenna device and a wireless communication device that can prevent the device from falling with a simple configuration.

[0006] An antenna device according to an embodiment of the present disclosure includes a flexible spacer that is attached to a main surface of a window glass with an adhesive, an antenna that is positioned opposite the main surface of the window glass, and a holding member that is attached to the spacer and holds the antenna.

[0007] It is possible to provide an antenna device and a wireless communication device that can prevent falling with a simple configuration.

[0008] 2A and 2B are enlarged views of the wireless communication device shown in FIG. 2A and 2B. FIG. ... 1 is a diagram showing an example of the operation of the spacer and the holder of the antenna device according to the embodiment in association with the opening operation of the window glass, and FIG. 2 is a diagram showing an example of the configuration of a transmission cable of the antenna device according to a modified example of the embodiment, and FIG. 3 is a diagram showing an example of the circuit configuration of the wireless device.

[0009] Hereinafter, embodiments to which the antenna device and wireless communication device of the present disclosure are applied will be described. In the following, the same elements will be denoted by the same reference numerals, and duplicated descriptions may be omitted.

[0010] The following description will be given by defining an XYZ coordinate system. 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 each other. The X axis is an example of a first axis, the Y axis is an example of a second axis, and the Z axis is an example of a third axis. The X direction is an example of a first axis direction, the Y direction is an example of a second axis direction, and the Z direction is an example of a third axis direction. The XYZ coordinate system is an example of a Cartesian coordinate system. In addition, the length, width, thickness, etc. of each part may be exaggerated below to make the configuration easier to understand. Furthermore, terms such as parallel, right angle, orthogonal, horizontal, vertical, up and down, etc., are intended to allow for deviations to the extent that they do not impair the effects of the embodiments.

[0011] In the following description, "radio waves" refers to a type of electromagnetic wave, and generally, electromagnetic waves of 3 THz or less are called radio waves. Hereinafter, electromagnetic waves of 3 THz or less emitted from an outdoor base station or relay station will be referred to as "radio waves," and electromagnetic waves in general will be referred to as "electromagnetic waves."

[0012] The radio waves relayed by the wireless communication device including the antenna device of the embodiment are preferably radio waves in a frequency band of 600 MHz to 40 GHz, including the Sub-6 frequency band and millimeter wave bands such as those of fifth-generation mobile communication systems (5G), and more preferably radio waves in a frequency band of 700 MHz to 30 GHz.The wireless communication device including the antenna device of the embodiment functions as a repeater that relays radio waves arriving from an outdoor base station or the like indoors.The repeater may also have the function of receiving radio waves arriving from an outdoor base station or the like, converting the radio waves into radio waves of a communication standard different from the communication standard of the radio waves arriving from the base station or the like, and relaying the converted radio waves indoors.

[0013] Furthermore, radio waves relayed by the wireless communication device including the antenna device of the embodiment may be Long Term Evolution (LTE), LTE-Advanced (LTE-A), Ultra Mobile Broadband (UMB), or Citizens Broadband Radio Service (CBRS). Furthermore, radio waves relayed by the wireless communication device of the embodiment may be IEEE 802.11 (Wi-Fi (registered trademark)), IEEE 802.16 (WiMAX (registered trademark)), IEEE 802.20, Ultra Wideband (UWB), Bluetooth (registered trademark), Low Power Wide Area (LPWA), or the like.

[0014] 1 is a plan view of an example of a building 1 in which a window 10 is installed with a wireless communication device 200 including an antenna device according to an embodiment. In addition to the building 1 and the wireless communication device 200, Fig. 1 also shows a base station BS, a PC (Personal Computer) 50, and a smartphone 60.

[0015] 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 a window glass and a window frame (the window frame on the building 1 side). The wireless communication device 200 functions as a repeater.

[0016] The antenna of the wireless communication device 200 is preferably provided on the window glass of the window 10, and the portions other than the antenna may be provided on the window 10, an indoor wall 1A near the window 10, a bay window frame, or the like. The antenna of the wireless communication device 200 is the antenna of the antenna device of the embodiment included in the wireless communication device 200. Furthermore, the portions other than the antenna of the wireless communication device 200 do not have to be fixed to the indoor wall 1A near the window 10, the ceiling, or the bay window frame, and may simply be placed on a flat surface, for example.

[0017] Radio waves in the Sub-6 frequency band and millimeter wave bands such as those of the fifth generation mobile communication system (5G) emitted from an outdoor base station BS enter the building 1 only through the glass of the window 10, but because they have a high degree of directivity, they only reach a part of the building, making it easy for dead zones to occur. The glass of the window 10 is the entrance point for radio waves into the building 1.

[0018] Because it is difficult to create a good communication environment indoors for radio waves in the Sub-6 frequency band or millimeter wave bands such as those of the fifth generation mobile communication system (5G), the antenna of the wireless communication device 200 is provided on the window 10 to improve the reception environment and expand the communication area. Here, providing the wireless communication device 200 on the window 10 means that, as described above, the antenna is provided on the window glass, and parts other than the antenna may be provided on the window 10 or an indoor wall 1A near the window 10, the frame of a bay window, or the like. When relaying radio waves, the wireless communication device 200 receives radio waves with the antenna through the window glass of the window 10, amplifies the radio waves, and radiates them indoors.

[0019] When relaying radio waves arriving from outside the window 10, the wireless communication device 200 amplifies the received radio waves and radiates the amplified radio waves indoors at a predetermined radiation angle using an array antenna or the like. The amplified radio waves are radiated over a wide area indoors, making it easy for indoor terminals to receive the radio waves.

[0020] For example, when relaying radio waves, the wireless communication device 200 may receive, amplify, and radiate radio waves of multiple frequencies. By relaying radio waves of multiple frequencies, the amplified radio waves can be radiated over a wider area indoors and communication performance can be improved.

[0021] Furthermore, radio waves in the Sub-6 frequency band or millimeter wave band such as that of the fifth generation mobile communication system (5G) are attenuated when they pass through the window glass of window 10. In order to suppress radio wave attenuation (loss), it is preferable to use a matching layer. By using a matching layer, when wireless communication device 200 relays radio waves, it is possible to reduce loss by adjusting the electrical length of the radio waves before or after they pass through the window glass to match the impedance.

[0022] <Outline of wireless communication device 200 and installation manner on building 1> Figures 2A and 2B are diagrams showing an outline of wireless communication device 200 and an example of installation manner on building 1. Figures 3A and 3B are enlarged views of wireless communication device 200 in Figures 2A and 2B. Figure 3C is a diagram showing an example of the configuration of antenna device 100 in an exploded state. Figures 2A, 2B, 3A, and 3B show window 10 as seen from the indoor side of building 1. As an example, wireless communication device 200 is installed indoors.

[0023] In the following, the X direction and Z direction are directions contained in a horizontal plane. In other words, the XZ plane is parallel to the horizontal plane. The Z direction is a direction that penetrates vertically through the wall 1A and the window 10, the Y direction is the vertical direction, and the X direction is the left-right direction of the window 10. Therefore, the +X direction is the right direction as viewed from the window 10, the -X direction is the left direction as viewed from the window 10, the +Y direction is the vertically upward direction, and the -Y direction is the vertically downward direction. In the following, the left-right direction when viewing the window 10 indoors will be used for explanation. The +Y direction side will be the upper side, and the -Y direction side will be the lower side.

[0024] 2A and 2B show a window 10 provided in an indoor wall 1A of a building 1. The window 10 is a sliding window including a window frame 11 attached to the wall 1A perpendicular to a horizontal plane, and a window pane 12. The sliding window 10 has two window panes 12. In FIG. 2A , the two window panes 12 are completely closed. The position of the two window panes 12 in this state is an example of the first position.

[0025] The wireless communication device 200 includes the antenna device 100, a transmission cable 170, and a wireless device 210. The antenna device 100 includes an antenna 110, a matching layer 120, a frame 130 (see FIG. 3B), and a reflector 140 (see FIG. 3C). The reflector 140 is an example of a reflecting portion. The frame 130 has a spacer 130A and a holder 130B.

[0026] The holder 130B is detachable from the spacer 130A. Fig. 2A shows a state in which the holder 130B is detached from the spacer 130A. Fig. 2B shows a state in which the spacer 130A and the holder 130B are coupled together.

[0027] For example, the user can attach the antenna device 100 and the wireless communication device 200 to the window glass 12 or the wall 1 A by himself / herself. In the following, the term “user” refers to a user of the antenna device 100 and the wireless communication device 200.

[0028] Unless otherwise specified, the following description will be given assuming that the window 10 is a sliding window including a window frame 11 and a window pane 12, but the window 10 may be any window as long as the window pane 12 can be opened and closed relative to the window frame 11. For this reason, the window 10 may also be a sliding window (for example, a horizontal sliding window or a vertical sliding window), a casement window, or the like.

[0029] The window frame 11 is a rectangular ring-shaped (frame-shaped) member that is attached to an opening for the window 10 provided in the wall 1A. The window frame 11 has rails that guide the window glass 12 in the X direction. The window frame 11 is made of, for example, a metal such as aluminum, resin, or wood. Below, a description will be given of an example in which the window frame 11 is made of metal.

[0030] The window glass 12 is attached to the window frame 11 so as to be movable in the ±X directions (horizontal direction). The window glass 12 includes a glass plate 12A and a frame portion 12B. The glass plate 12A is an example of a dielectric plate and, for example, is a transparent glass plate that is rectangular in XY plane (plan view). "Transparent" means that the luminous transmittance is at least 40%, preferably 60% or more, more preferably 70% or more, and even more preferably 80% or more. The frame portion 12B is, for example, a rectangular ring-shaped (frame-shaped) member that surrounds the outer edge of the glass plate 12A and is movable in the ±X directions (horizontal direction) along rails (not shown) of the window frame 11 on the building 1 side. Note that the window glass 12 does not necessarily have to include the frame portion 12B. In this case, the window glass 12 includes only the glass plate 12A. Furthermore, the glass plate 12A is not limited to being rectangular in XY plane view, and may have a curved outer edge, such as a circular or elliptical shape. In this case, the frame portion 12B may be a frame-shaped member that surrounds the glass plate 12A having such a curved outer edge.

[0031] The glass plate 12A may be made of any transparent dielectric material, and more specifically, may be any commonly available glass, such as soda-lime glass, alkali-free glass, Pyrex (registered trademark) glass, or quartz glass. The glass plate 12A is not limited to a glass plate, and may be a surface material made of a resin such as polycarbonate. Both surfaces of the glass plate 12A are main surfaces of the glass plate 12A, and the surface of the glass plate 12A facing the indoor side (+Z direction side) is an example of a first main surface facing the indoor side.

[0032] The frame portion 12B is a frame-shaped member that surrounds the edge of the glass plate 12A and is made of metal such as aluminum, resin, wood, etc. Below, a description will be given of an example in which the frame portion 12B is made of metal.

[0033] <Configuration of wireless communication device 200 and attachment structure to window 10> The wireless communication device 200 includes an antenna device 100, a transmission cable 170, and a wireless device 210. The transmission cable 170 is an example of a transmission path. As an example, the wireless communication device 200 is provided on the indoor side of a building 1 (see FIG. 1 ). In the following, a wall 1A refers to an indoor wall 1A unless otherwise specified.

[0034] Here, a configuration will be described in which the window glass 12 is rectangular in plan view and the window frame 11 is frame-shaped (rectangular ring-shaped) in plan view, but the window glass 12 is not limited to being rectangular in plan view and may have a shape with a curved outer edge, such as a circle or ellipse. In this case, the window frame 11 may be a frame-shaped member that surrounds the window glass 12 having such a curved outer edge.

[0035] Furthermore, viewing the window glass 12 in a plan view (XY plane view) means viewing the window glass 12 from a direction directly opposite the main surface, and in the case of the antenna device 100 and the wireless communication device 200, viewing the window glass 12 in a direction directly opposite the main surface when attached to the window glass 12 and window frame 11 is also referred to as a plan view.

[0036] <Transmission Cable 170> As an example, two transmission cables 170 are provided between the antenna device 100 and the wireless device 210. The two transmission cables 170 are arranged parallel to each other with a gap in the X direction and have the same length. As an example, the transmission cables 170 may be configured to guide two types of radio waves (high frequency signals), one horizontally polarized and one vertically polarized.

[0037] The transmission cable 170 is, for example, a coaxial cable. Instead of a coaxial cable, the following transmission path may be used as the transmission cable 170. For example, an FPC (Flexible Printed Circuit) transmission path having a transmission line such as a microstrip line (MSL) or a coplanar waveguide (CPW) formed on a flexible substrate made of polyimide or the like may be used. 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. When a coaxial cable or the above-mentioned transmission path is used as the transmission cable 170, an RF component such as an amplifier may be mounted on the transparent antenna device 100 side.

[0038] Also, instead of the transmission cable 170, a bendable flexible waveguide may be used as the transmission path.

[0039] The transmission cable 170 has an end (first end) connected to the holder 130B of the antenna 110 of the antenna device 100 and an end (second end) connected to the wireless device 210, and transmits radio waves received by the antenna device 100. Here, as an example, a configuration in which the wireless communication device 200 includes two transmission cables 170 will be described, but the number of transmission cables 170 may be one, or three or more.

[0040] 2A , when the holder 130B is not coupled to the spacer 130A, the transmission cable 170 suspends the antenna 110, the matching layer 120, and the holder 130B relative to the wireless device 210. In this state, the transmission cable 170 extends straight downward from the wireless device 210.

[0041] 2B, when holder 130B is coupled to spacer 130A, holder 130B has moved in the -Z direction compared to the state shown in Fig. 2A, so transmission cable 170 is gently bent from the lower end of wireless device 210 toward spacer 130A when viewed from the YZ plane. Transmission cable 170 is almost inelastic, but can be bent at any position between the two ends.

[0042] <Arrangement of wireless device 210> The wireless device 210 is fixed to the indoor wall 1A in a portion directly above the window frame 11. More specifically, the wireless device 210 is fixed to the indoor wall 1A directly above the end of the window frame 11 on the −X direction side in a portion above the window glass 12. The wireless device 210 may be fixed to the wall 1A with screws or the like, or may be attached by adhering to the wall 1A with double-sided tape or the like. The wireless device 210 may also be fixed to the wall 1A via a bracket or the like. Fixing with screws is particularly effective when the surface of the window frame 11 is not flat or when double-sided tape is difficult to use for fixing due to its material. The wireless device 210 may also be fixed to the indoor window frame 11.

[0043] The wireless device 210 has a wireless communication unit in addition to the housing 210A and the array antenna 210B. The array antenna 210B and the wireless communication unit are arranged inside the housing 210A. The wireless device 210 may also have a heat dissipation unit that dissipates heat from the wireless communication unit. The housing 210A is, for example, a rectangular parallelepiped resin case. The housing 210A is fixed to the wall 1A, thereby fixing the wireless device 210 to the wall 1A. The array antenna 210B is provided on the +Z direction side inside the housing 210A. The wireless communication unit is omitted here. The wireless communication unit will be described later using FIG. 8.

[0044] The wireless communication unit is connected to the end of the transmission cable 170 (the end connected to the wireless device 210), and performs processes such as amplifying the radio waves received from the antenna device 100 via the transmission cable 170 and outputting the amplified waves to the array antenna 210B, and controlling the radiation direction in which the array antenna 210B radiates the radio waves. For this reason, the wireless communication unit includes an amplifier, a microcomputer, etc.

[0045] When the wireless communication device 200 is attached to the window 10, it is better to place it on the indoor side of the building 1 (see FIG. 1 ) to protect it from wind, rain, dust, etc., and to ensure stable operation over a long period of time. For this reason, the wireless communication device 200 is placed indoors.

[0046] Furthermore, when the wireless communication device 200 is attached to the window 10, it is preferable that the antenna device 100 be provided in a portion that overlaps with the window glass 12 in order to efficiently receive radio waves that pass through the window glass 12. For this reason, in one embodiment, as an example, each portion of the antenna device 100 is made transparent, and the antenna device 100 is attached to the window glass 12, thereby realizing efficient reception of radio waves propagating from outdoors and suppressing obstruction of the view of the window glass 12.

[0047] On the other hand, the amplifier, microcomputer, etc. of the wireless device 210 generate heat due to amplification processing and control of the array antenna 210B, and if the wireless device 210 is attached to the window glass 12, the heat may damage or break the window glass 12. It is also difficult to make the wireless device 210 itself optically transparent. For these reasons, it is more convenient to attach the wireless device 210 to a structure such as the window frame 11 or the wall 1A surrounding the window frame 11. In particular, if the window frame 11 is made of metal, it is possible to dissipate the heat generated by the wireless device 210 through the window frame 11. The structure such as the window frame 11 or the wall 1A surrounding the window frame 11 is the window 10 or the wall 1A surrounding the window 10. The structure surrounding the window 10 also includes a desk near the window 10, the frame of a bay window, etc.

[0048] For the reasons described above, in the embodiment, the antenna device 100 is attached to the indoor main surface of the window glass 12, and the wireless device 210 is attached to the wall 1A directly above the indoor window frame 11. Here, as an example, a configuration will be described in which the antenna device 100 is attached to the upper side of the indoor main surface of the window glass 12, and the wireless device 210 is attached to the wall 1A above the window frame 11. However, the same applies to a configuration in which the antenna device 100 is attached to a part of the indoor main surface of the window glass 12 other than the upper side, and the wireless device 210 is attached to a part of the wall 1A other than the upper side of the window frame 11, or to the window frame 11.

[0049] <Configuration of Antenna Device 100> The antenna device 100 includes an antenna 110, a matching layer 120, a frame 130, and a reflector 140. The frame 130 has a spacer 130A and a holder 130B. The holder 130B has a first holder 130B1 and a second holder 130B2.

[0050] Unless otherwise specified, the configuration of the antenna device 100 will be described in a state where the spacer 130A and the holder 130B are coupled together as shown in FIGS. 2B and 3B.

[0051] Although the number of antennas 110 may be one, a configuration including a plurality of antennas 110 will be described here as an example, as a configuration capable of MIMO (Multi-Input Multi-Output) communication.

[0052] <Antenna 110> The antenna 110 is disposed on the indoor side of the window glass 12, and as an example, is disposed at a distance from the window glass 12. The antenna 110 is held together with the matching layer 120 by a holder 130B of the frame 130, and is disposed at a distance from the window glass 12. The antenna 110 faces the indoor main surface of the window glass 12.

[0053] As shown in Fig. 3C, the antenna 110 is sandwiched together with the matching layer 120 between the first holder 130B1 and the second holder 130B2 of the holder 130B of the frame 130. Fig. 3C shows an exploded state, but by fixing the first holder 130B1 and the second holder 130B2 with the antenna 110 and the matching layer 120 sandwiched between them, the antenna 110 is held in the holder 130B together with the matching layer 120.

[0054] The antennas 110 have the same configuration and are equally spaced from the main surface of the interior side of the window glass 12. Each antenna 110 is, for example, a patch antenna, a monopole antenna, a dipole antenna, or a spiral antenna.

[0055] Each antenna 110 is connected to a wireless device 210 via a transmission cable 170. The antenna 110 and the wireless device 210 may be connected by a transmission path capable of transmitting radio waves, and are connected by the transmission cable 170 as an example.

[0056] Each antenna 110 receives radio waves that have passed through the window glass 12 and the matching layer 120. Furthermore, the radio waves radiated from each antenna 110 pass through the matching layer 120 and the window glass 12 and are transmitted to the outside of the building 1.

[0057] The antenna 110 receives radio waves emitted from an outdoor base station BS, etc. The operating frequency of the antenna 110 is a frequency included in the Sub-6 band or the millimeter wave band.

[0058] The antenna 110 has a substrate and an antenna element formed on the surface of the substrate. The antenna element is, for example, a radiating element for a patch antenna, a monopole antenna, a dipole antenna, or a spiral antenna. For example, the antenna element is formed on the surface of the substrate on the −Z direction side. The substrate is preferably transparent. Here, "transparent" means being transparent to visible light. "Transparent" to visible light means having a luminous transmittance of at least 40% or more, preferably 60% or more, more preferably 70% or more, and even more preferably 80% or more.

[0059] The antenna 110 is preferably placed close to the window glass 12. This is because it is easier to receive radio waves when the antenna is closer to the window glass 12. As an example, the distance in the Z direction between the antenna 110 and the indoor main surface of the window glass 12 is preferably about 10 mm to 50 mm, and more preferably 20 mm to 30 mm.

[0060] The substrate of the antenna 110 is formed of any material that is transparent to radio waves radiated from an outdoor base station and that can support an antenna element. "Transparent to radio waves" means, for example, that the transmission loss is 10 dB or less. "Transparent to radio waves" means that the transmission loss of the substrate is 10 dB or less, preferably 6 dB or less, more preferably 3 dB or less, and even more preferably 1 dB or less.

[0061] The substrate of the antenna 110 may be transparent to visible light. "Transparent" to visible light 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.

[0062] As an example, a transparent glass plate is used as the substrate of antenna 110. Alternatively, a transparent resin base material may be used as the substrate of antenna 110. Examples of resin materials that satisfy the above conditions include acrylic resins such as polymethyl methacrylate, cycloolefin resins, polycarbonate resins, and polyethylene terephthalate (PET).

[0063] The antenna element of the antenna 110 is made of a conductor. Since the antenna device 100 is placed over the window 10, the antenna element is made of zinc oxide (ZnO), tin oxide (SnO ２ It is desirable that the antenna 110 be formed from a transparent conductive film such as 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 antenna 110 may be formed from 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.

[0064] 3C , the matching layer 120 is sandwiched together with the antenna 110 between the first holder 130B1 and the second holder 130B2 of the holder 130B of the frame 130. The matching layer 120, together with the antenna 110, is held by the holder 130B of the frame 130.

[0065] The matching layer 120 has a surface facing the window glass 12 and a surface facing the indoor side opposite the window glass 12. The surface of the matching layer 120 facing the window glass 12 is positioned at a predetermined distance from the indoor main surface of the window glass 12.

[0066] The matching layer 120 is provided to adjust the electrical length of the radio waves incident on the antenna 110 and match the impedance. The matching layer 120 may be made of a material that is transparent to the radio waves emitted from the outdoor base station. "Transparent to the radio waves" means, for example, that the transmission loss is 10 dB or less. "The matching layer 120 is transparent to the radiated radio waves" means that the transmission loss of the matching layer 120 is 10 dB or less, preferably 6 dB or less, more preferably 3 dB or less, and even more preferably 1 dB or less.

[0067] The matching layer 120 may be transparent to visible light. "Transparent" to visible light 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.

[0068] The matching layer 120 can be made of, for example, polycarbonate, acrylic, COP (cycloolefin polymer), PET (polyethylene terephthalate), polystyrene, or glass.

[0069] From the viewpoint of suppressing bending, it is preferable that the matching layer 120 has a thickness of 0.5 mm or more. If the matching layer 120 bends, the characteristic of adjusting the electrical length of the radio wave becomes non-uniform in the XY plane, which may cause variations in the degree of impedance matching.

[0070] The thickness of the matching layer 120 in the Z direction is, for example, constant throughout. From the viewpoint of increasing the luminous transmittance, the thickness of the matching layer 120 is preferably 20 mm or less, and more preferably 15 mm or less. Furthermore, for example, the thickness of the matching layer 120 is more preferably 0.5 mm to 5 mm. The matching layer 120 may be a single layer, or may be a configuration in which multiple layers are stacked, or multiple layers are arranged at intervals.

[0071] The distance between the matching layer 120 and the window glass 12 is preferably greater than 0 mm and equal to or less than 40 mm, and more preferably in the range of 10 mm to 20 mm.

[0072] The matching layer 120 adjusts the electrical length of the radio waves incident on the antenna 110, and therefore its effective thickness varies depending on the dielectric constant. This is because the degree of the effect of shortening the wavelength of the radio waves varies depending on the dielectric constant. Therefore, from the perspective of matching the impedance of the radio waves, the effective thickness of the matching layer 120 should be set to an appropriate effective thickness that allows impedance matching.

[0073] The matching layer 120 may be provided on the spacer 130 A. Furthermore, if there is no particular problem in not including the matching layer 120, the antenna device 100 may not include the matching layer 120.

[0074] <Frame 130> The frame 130 (see FIG. 3B) has a spacer 130A and a holder 130B. The holder 130B has a first holder 130B1 and a second holder 130B2 (see FIG. 3C).

[0075] <Spacer 130A> The spacer 130A is attached to the indoor main surface of the window glass 12 by an adhesive layer 135A. The adhesive layer 135A is an example of an adhesive. The spacer 130A is flexible. The spacer 130A being flexible means that the spacer 130A has a degree of flexibility that allows a user attempting to attach the antenna device 100 to the window glass 12 to bend the spacer 130A by hand, and that the spacer 130A bends supplely.

[0076] As an example, if the thickness of the spacer 130A is t and the Young's modulus of the spacer 130A is E, t is 0.1 mm to 5 mm, and E is 1 GPa to 10 GPa. That is, t × E is 0.1 GPa·mm to 50 GPa·mm. This is to ensure that the spacer 130A is flexible enough that a user can bend it by hand, and also to prevent air bubbles from forming between the main surface of the window glass 12 and the adhesive layer 135A when the spacer 130A is attached to the interior main surface of the window glass 12 with the adhesive layer 135A. The reduction in adhesive strength due to the formation of air bubbles will be described later using Figures 5A to 5C.

[0077] As an example, the spacer 130A is a thin sheet-like member that is frame-shaped (rectangular ring-shaped) in a plan view as shown in FIG. 3C. In other words, the spacer 130A is a plate-like body that is frame-shaped (rectangular ring-shaped) in a plan view. The spacer 130A being a plate-like body allows the holder 130B to be stably attached. As an example, the thickness of the spacer 130A is approximately 0.5 mm to 5 mm, and more preferably 0.5 mm to 3 mm.

[0078] Here, an embodiment will be described in which the spacer 130A has a frame shape (rectangular ring shape) in a plan view, for example. The spacer 130A has the same shape as the holder 130B, which also has a frame shape (rectangular ring shape) in a plan view, for example.

[0079] The spacer 130A has a frame-like (rectangular ring) shape so that it does not overlap with the antenna element of the antenna 110 in a plan view. This is because transmission loss occurs when radio waves pass through the spacer 130A, which is made of a resin material. However, as an example, if the radio wave transmission loss is small and not a problem, the spacer 130A may overlap with the antenna element of the antenna 110 in a plan view. The same applies to the holder 130B.

[0080] Furthermore, spacer 130A is not limited to a configuration having a frame-like (rectangular ring) shape in a plan view, but may be provided along at least two sides along the outer edge of holder 130B in a plan view. This is because if spacer 130A is provided along at least two sides along the outer edge of holder 130B in a plan view, holder 130B can be stably held and will not overlap with the antenna element of antenna 110 in a plan view. As an example, spacer 130A may be provided along four sides along the outer edge of holder 130B in a plan view.

[0081] The spacer 130A is preferably transparent. Here, "transparent" means transparent to visible light. "Transparent" to visible light 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.

[0082] Such a spacer 130A can be formed from a flexible resin material such as PET (Polyethylene terephthalate), polycarbonate, acrylic (Polymenthyl methacrylate), fluororesin, COP (Cyclo-Olefin Polymer), PEN (polyethylene naphthalate), polyimide, Peek (polyether ether ketone), LCP (Liquid Crystal Polymer), or other composite materials.

[0083] <Coupling Portion 131A> The spacer 130A has a coupling portion 131A (see FIG. 3C). As an example, the coupling portion 131A is provided on the surface of the spacer 130A on the +Z direction side. FIG. 3C shows, as an example, a configuration in which one coupling portion 131A is disposed at each of the four corners of the spacer 130A. However, at least one coupling portion 131A is sufficient, and more than four coupling portions 131A may be provided. The multiple coupling portions 131A may be disposed on the spacer 130A in any manner as long as stable coupling and separation with the holder 130B can be achieved.

[0084] The coupling part 131A is detachable from the coupling part 131B provided on the surface of the first holder 130B1 of the holder 130B on the -Z direction side, and can be repeatedly switched between being coupled to the coupling part 131B and being separated from the coupling part 131B. Details of the coupling part 131A will be described later.

[0085] <Holder 130B> As described above, the holder 130B has the first holder 130B1 and the second holder 130B2. The first holder 130B1 and the second holder 130B2 are fixed to each other with the antenna 110 and the matching layer 120 sandwiched between them. The first holder 130B1 and the second holder 130B2 may be fixed using an engaging portion such as a snap fit, or may be fixed using an adhesive or the like.

[0086] 3C, the first holder 130B1 and the second holder 130B2 are, for example, thin sheet-like members that are frame-shaped (rectangular annular) in plan view, similar to the spacer 130A, and for example, have the same shape. Here, a configuration in which the first holder 130B1 and the second holder 130B2 have the same shape will be described as an example, but the first holder 130B1 and the second holder 130B2 may have different shapes and may also have different sizes.

[0087] The thickness of the first holder 130B1 is, for example, about 1 mm to 5 mm, and more preferably 2 mm to 4 mm. The thickness of the second holder 130B2 is, for example, about 1 mm to 5 mm, and more preferably 2 mm to 4 mm. The thicknesses of the first holder 130B1 and the second holder 130B2 may be different or the same.

[0088] The first holder 130B1 and the second holder 130B2 are preferably transparent. Here, "transparent" means transparent to visible light. "Transparent" to visible light 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.

[0089] One end of the transmission cable 170 is connected to the second holder 130B2. As an example, the transmission cable 170 is coupled to the antenna 110 via the second holder 130B2 in a non-contact manner. In this manner, the antenna 110 and the transmission cable 170 are configured to be able to transmit a signal (AC signal) via the second holder 130B2.

[0090] The first holder 130B1 and the second holder 130B2 are harder than the spacer 130A and have a hardness that prevents them from bending even when a user who is attempting to attach the antenna device 100 to the window glass 12 applies force to the first holder 130B1 and the second holder 130B2 with their hands. In other words, the first holder 130B1 and the second holder 130B2 are less likely to bend than the spacer 130A and barely bend at all. In other words, the spacer 130A is more likely to bend than the first holder 130B1 and the second holder 130B2. Note that being hard corresponds to a large value of Young's modulus x thickness.

[0091] Examples of transparent resin materials from which the first holder 130B1 and the second holder 130B2 can be made include acrylic resins such as polymethyl methacrylate, cycloolefin resins, polycarbonate resins, and polyethylene terephthalate (PET).

[0092] <Coupling portion 131B> The first holder 130B1 has a coupling portion 131B (see FIG. 3C). As an example, the coupling portion 131B is provided on the surface of the first holder 130B1 on the -Z direction side. FIG. 3C shows, as an example, a configuration in which one coupling portion 131B is disposed at each of the four corners of the first holder 130B1. However, at least one coupling portion 131B is sufficient, and there may be more than four coupling portions 131B. The position of the coupling portion 131B is aligned with the position of the coupling portion 131A, and they are positioned so as to overlap in a plan view.

[0093] The connecting portion 131B is detachable from the connecting portion 131A provided on the surface of the spacer 130A on the +Z direction side, and can be repeatedly connected to the connecting portion 131A and separated from the connecting portion 131A.

[0094] <Coupling Portions 131A and 131B> The coupling portions 131A and 131B are configured to be repeatedly detachable from each other. Examples of such combinations of coupling portions 131A and 131B include a combination of a magnet and a magnetic material utilizing magnetic force, a combination of a convex button and a concave button utilizing a mating force, and a combination of a hook-and-loop fastener with an A-side (male) and a B-side (female) utilizing an interlocking force. The combination of coupling portions 131A and 131B may also be a combination of interlocking convex and concave portions. Thus, the coupling portions 131A and 131B may be configured to be detachably coupled by magnetic force, interlocking force, or interlocking force, for example. Therefore, the spacer 130A and the holder 130B can be detachably coupled with each other using a simple configuration utilizing magnetic force, interlocking force, or interlocking force.

[0095] Since the spacer 130A and the holder 130B can be detachably coupled, when the spacer 130A and the holder 130B are separated as shown in Figures 2A and 3A, and the holder 130B is brought close to the spacer 130A to couple them together, they become coupled as shown in Figures 2B and 3B. Note that the method of attaching the spacer 130A to the window glass 12 and the operation of attaching and detaching the spacer 130A and the holder 130B using the coupling portions 131A and 131B will be described later.

[0096] <Reflector 140> The reflector 140 is fixed to the −Z direction side of the second holder 130B2 of the holder 130B. The reflector 140 is, for example, a plate-shaped member. The reflector 140 is preferably transparent. The reflector 140 has a configuration in which a metal film is formed on a transparent resin substrate, for example. Examples of the metal film of the reflector 140 include zinc oxide (ZnO), tin oxide (SnO ２ Examples of the metal film include transparent conductive films such as tin-doped indium oxide (ITO) and indium oxide-tin oxide (IZO), metal nitrides such as titanium nitride (TiN) and chromium nitride (CrN), and low-e films for low-e (low emissivity) glass. However, the metal film of the reflector 140 may be formed from a thin metal film such as copper, nickel, or gold. In the case of a thin metal film, it is preferable to form it in a mesh shape from the viewpoint of visibility.

[0097] For example, if the second holder 130B2 is plate-shaped rather than frame-shaped, the reflector 140 may be a metal film or the like formed on the surface of the plate-shaped second holder 130B2 on the +Z direction side.

[0098] By using such a reflector 140, radio waves emitted from the antenna 110 in the +Z direction can be reflected toward the window glass 12, thereby improving communication conditions with the outdoor base station BS.

[0099] <Method of attaching spacer 130A to window glass 12> Here, we will explain a method of attaching spacer 130A to window glass 12, but before that, we will explain a method of attaching a comparative frame 30 to window glass 12 using Figures 4A and 4B.

[0100] 4A and 4B are diagrams illustrating an example of a method for attaching the comparative frame 30 to the window glass 12. Here, the comparative frame 30 is attached to the indoor main surface of the window glass 12 using an adhesive layer 135A.

[0101] The comparative frame 30 is made of the same resin material as the resin material used to make the holder 130B of the embodiment, and therefore hardly bends. As shown in Fig. 4A, when the frame 30 is attached to the indoor main surface of the window glass 12 using the adhesive layer 135A, the frame 30 hardly bends, and therefore, as shown in Fig. 4B, air bubbles 135A1 are formed between the indoor main surface of the window glass 12 and the adhesive layer 135A. The air bubbles 135A1 are air or the like that has entered between the indoor main surface of the window glass 12 and the surface of the adhesive layer 135A on the -Z direction side, and the adhesive layer 135A is not adhered to the indoor main surface of the window glass 12 in the areas of the air bubbles 135A1.

[0102] If air bubbles 135A1 occur in the adhesive layer 135A, the area of ​​the frame 30 that adheres to the window glass 12 will be reduced, which will result in insufficient adhesion of the frame 30 to the window glass 12, and there is a risk that the frame 30 will fall off. In particular, if the frame 30 holds the antenna 110, the matching layer 120, etc., there is a risk that the antenna 110, the matching layer 120, etc. will fall off.

[0103] 5A to 5C are diagrams illustrating an example of a method for attaching the frame 130 of the embodiment to the window glass 12. The frame 130 is divided into a flexible spacer 130A and a holder 130B.

[0104] First, as shown in Figure 5A, spacer 130A is attached to the indoor main surface of window glass 12 using adhesive layer 135A. Spacer 130A bends simply by applying a force to bend spacer 130A by hand when a user tries to bend it. For this reason, for example, by gradually attaching spacer 130A with adhesive layer 135A attached to it while pressing it against the indoor main surface of window glass 12 from the bottom end, the entire surface of adhesive layer 135A on the -Z direction side can be attached to the indoor main surface of window glass 12 without generating any air bubbles, as shown in Figure 5B. Because no air bubbles are generated, the adhesive strength of spacer 130A to window glass 12 is strong.

[0105] 5C, the holder 130B is coupled to the surface of the spacer 130A on the +Z direction side. The antenna 110 and the matching layer 120 are sandwiched between the first holder 130B1 and the second holder 130B2 of the holder 130B, and the reflector 140 is attached to the +Z direction side of the second holder 130B2.

[0106] In this way, by connecting the holder 130B to the surface of the spacer 130A on the +Z direction side, the antenna 110, the matching layer 120, and the reflector 140 can be easily attached to the window glass 12. The spacer 130A and the holder 130B can be detached by the connecting portions 131A and 131B, and therefore can be repeatedly attached and detached.

[0107] 5D is a diagram illustrating an example of a method for attaching a spacer 130MA according to a modified embodiment to the indoor main surface of the window glass 12. Two spacers 130MA are attached to an alignment sheet 132MA and temporarily fixed to prevent misalignment of the two spacers 130MA. An adhesive layer 135A is attached to the surface of each of the two spacers 130MA facing in the -Z direction.

[0108] When attaching the two spacers 130MA to the indoor main surface of the window glass 12, if the two spacers 130MA temporarily fixed with the alignment sheet 132MA are attached with the adhesive layer 135A in the same manner as the spacer 130A shown in Figure 5A, the two spacers 130MA can be firmly adhered to the indoor main surface of the window glass 12 without air bubbles being generated in the adhesive layer 135A.

[0109] After the two spacers 130MA have been attached to the main surface of the window glass 12 facing the interior, the alignment sheet 132MA is peeled off from the two spacers 130MA, and the holder 130B is attached.

[0110] By using the alignment sheet 132MA, the plurality of spacers 130MA can be easily attached to the indoor main surface of the window glass 12 without generating air bubbles in the adhesive layer 135A and with high positional accuracy.

[0111] <Operation of the spacer 130A and the holder 130B in association with the opening of the window glass 12> The spacer 130A and the holder 130B can be detachably coupled to each other by using the coupling portions 131A and 131B. The first holder 130B1 is fixed to the second holder 130B2 with the antenna 110 and the matching layer 120 sandwiched between the first holder 130B1 and the second holder 130B2.

[0112] Furthermore, the bonding force between the spacer 130A and the holder 130B is smaller than the destructive force of the holder 130B. The destructive force of the holder 130B is the minimum external force that can destroy the holder 130B. For example, if the transmission cable 170 is pulled, the holder 130B will come off the spacer 130A before the joint between the holder 130B and the transmission cable 170 is damaged. This relationship in the bonding force between the spacer 130A and the holder 130B enables the operation described below with reference to Figures 6A to 6C.

[0113] 6A to 6C are diagrams showing an example of the operation of the spacer 130A and the holder 130B in accordance with the opening operation of the window glass 12. Here, the operation will be described using FIG. 3B in addition to FIG. 6A to 6C.

[0114] As shown in Fig. 3B, when the window glass 12 on the -X side is completely closed, the holder 130B is coupled to the spacer 130A. When the window glass 12 on the -X side begins to be opened in the +X direction from this state, the transmission cable 170 follows the holder 130B, and the lower end of the transmission cable 170 bends in the +X direction, as shown in Fig. 6A.

[0115] If the window glass 12 on the -X direction side is further moved in the +X direction, the holder 130B will come off the spacer 130A when the window glass 12 moves to the position shown in Fig. 6B. The position of the window glass 12 on the -X direction side shown in Fig. 6B is an example of the second position. This is because the bonding force between the spacer 130A and the holder 130B is smaller than the tensile strength of the transmission cable 170 and is also smaller than the joining force between the end (first end) of the transmission cable 170 and the holder 130B.

[0116] 6C , when the window glass 12 on the −X direction side is further moved in the +X direction, the spacer 130A is accommodated between the window glass 12 on the +X direction side and the window glass 12 on the −X direction side. If the thickness of the spacer 130A in the Z direction is set to a thickness that allows it to be accommodated between the two window glasses 12, taking into account the thickness of the adhesive layer 135A, the spacer 130A will not interfere with the window glass 12 on the +X direction side, and the window glass 12 on the −X direction side can be fully opened. In other words, it is possible to provide an antenna device 100 that does not interfere with the opening and closing operation of the window glass 12.

[0117] 6C, when holder 130B is detached from spacer 130A and window glass 12 and antenna 110 are not overlapped, antenna 110 can receive radio waves that have only passed through matching layer 120. In other words, in this state, antenna 110, from which spacer 130A has been detached, can communicate with an outdoor base station BS through window 10.

[0118] When the user closes the window glass 12 again, the holder 130B separates from the spacer 130A and faces it, as shown in Figures 2A and 3A. In this state, if the user picks up the holder 130B and connects it to the spacer 130A, the holder 130B is connected to the spacer 130A, as shown in Figures 2B and 3B, and the antenna 110 can communicate with the outdoor base station BS through the window glass 12.

[0119] Every time the user opens the window glass 12, the holder 130B is pulled by the transmission cable 170 and detached from the spacer 130A. Every time the user closes the window glass 12, the holder 130B is simply attached to the spacer 130A. The spacer 130A and the holder 130B can be easily reattached by the connecting portions 131A and 131B, so the spacer 130A and the holder 130B can be repeatedly separated and attached. Furthermore, because the connecting portions 131A and 131B are very easy to attach, the user can easily attach the spacer 130A and the holder 130B.

[0120] 7 is a diagram showing an example of the configuration of a transmission cable 170M according to a modified example of the embodiment. The transmission cable 170M includes a cover 170MA, a coaxial cable 171M, and a metal wire 172M. The coaxial cable 171M is an example of a transmission path, and the metal wire 172M is an example of a reinforcing member.

[0121] FIG. 7 shows a portion of the transmission cable 170M in the longitudinal direction with a portion of the cover 170MA omitted so that the internal structure of the transmission cable 170M can be seen.

[0122] 7 shows, as an example, a configuration in which one transmission cable 170M includes two coaxial cables 171M and one metal wire 172M. However, it is sufficient that the transmission cable 170M includes at least one coaxial cable 171M and one metal wire 172M.

[0123] The coaxial cable 171M connects the switch 212 of the wireless device 210 and the antenna 110. That is, one end of the coaxial cable 171M is connected to the switch 212 of the wireless device 210, and the other end is connected to the antenna 110.

[0124] Metal wire 172M connects housing 210A of wireless device 210 and second holder 130B2. That is, one of both ends of metal wire 172M is connected to housing 210A of wireless device 210, and the other end is connected to second holder 130B2.

[0125] The length of metal wire 172M is shorter than the length of coaxial cable 171M. More specifically, the length between holder 130B of metal wire 172M and housing 210A of wireless device 210 is shorter than the length between holder 130B of coaxial cable 171M and housing 210A of wireless device 210. For this reason, when window glass 12 on the −X direction side is completely closed and holder 130B is coupled to spacer 130A, and then window glass 12 is opened, the following occurs.

[0126] When the window glass 12 moves and the distance between the antenna device 100 and the wireless device 210 increases, the transmission cable 170 is pulled between the antenna device 100 and the wireless device 210. Then, when the metal wire 172M is fully stretched between the housing 210A and the second holder 130B2, the coaxial cable 171M is not fully stretched between the switch 212 and the antenna 110. This is because the coaxial cable 171M is longer than the metal wire 172M.

[0127] The holder 130B is pulled by the stretched metal wire 172M, and the second holder 130B2 is detached from the spacer 130A, resulting in the state shown in Fig. 6B. As a result, both ends of the coaxial cable 171M are not pulled, and the connection between both ends of the coaxial cable 171M and the switch 212 and the antenna 110 is maintained in a good state.

[0128] Furthermore, when the user has completely closed the window glass 12 again, the user can pick up the holder 130B and connect it to the spacer 130A, returning the holder 130B to the state where it is connected to the spacer 130A.

[0129] Each time the user opens the window glass 12, the holder 130B is pulled by the metal wire 172M and detached from the spacer 130A. Each time the user closes the window glass 12, the holder 130B can be connected to the spacer 130A.

[0130] The metal wire 172M bears the load applied to the transmission cable 170M when the window glass 12 is opened, so that the connectivity of the coaxial cable 171M can be maintained in a good state for a long period of time.

[0131] <Circuit Configuration of Wireless Device 210> The wireless device 210 will be described using Fig. 8 in addition to Figs. 2A to 3C. Fig. 8 is a diagram showing an example of the configuration of the wireless device 210. Fig. 8 shows the configuration of a portion of the overall configuration of the wireless device 210 that corresponds to one antenna 110. The antenna 110 is connected to the wireless device 210 via a transmission cable 170.

[0132] A long distance between the antenna 110 and the wireless device 210 increases the transmission loss of radio waves between the antenna 110 and the wireless device 210. Therefore, in order to reduce the transmission loss of radio waves, it is preferable to attach the wireless device 210 to the window glass 12, or to the wall 1A or ceiling around the window 10.

[0133] Furthermore, in order to reduce transmission loss of radio waves between the antenna 110 and the wireless device 210, a bendable transmission cable 170 is used, for example, as a transmission path connecting the antenna 110 and the wireless device 210. By using the bendable transmission cable 170, radio waves can be propagated efficiently between the antenna 110 and the wireless device 210 with little transmission loss.

[0134] The wireless device 210 includes a wireless module 211, a switch 212, a low noise amplifier (LNA) 213, a mixer 214, an analog to digital converter (ADC) 215, a digital to analog converter (DAC) 216, a mixer 217, and a power amplifier (PA) 218. The wireless module 211 to the PA 218 are an example of a wireless communication unit of the wireless device 210.

[0135] Of the wireless device 210, the switch 212, the LNA 213, the mixer 214, the ADC 215, the DAC 216, the mixer 217, and the PA 218 are provided one for each antenna 110. The wireless device 210 includes the same number of components from the switch 212 to the PA 218 as the number of antennas 110. As an example, there is one wireless module 211 that is common to the four antennas 110.

[0136] The wireless module 211 is configured, for example, by an MCU (Micro Controller Unit), and includes a control unit 211A and a relay unit 211B that performs relay processing. The control unit 211A and the relay unit 211B are functional blocks that represent the functions executed by the MCU.

[0137] When receiving radio waves through antenna 110, control unit 211A switches three-terminal switch 212 to connect antenna 110 to LNA 213. When transmitting radio waves through antenna 110, control unit 211A switches three-terminal switch 212 to connect antenna 110 to PA 218.

[0138] The relay unit 211B includes, as an example, a Bluetooth (registered trademark) communication unit, is connected to the array antenna 210B, and transmits a digital signal input from the ADC 215 from the array antenna 210B to the inside of the building 1. When the relay unit 211B transmits a signal to the inside of the building 1 via the array antenna 210B, the radio waves received by the antenna 110 from the base station BS are relayed, and the radio waves are radiated to the inside of the building 1 where the wireless communication device 200 is located. As a result, the radio waves are radiated over a wide area inside the building 1, making it easier for terminals such as the smartphone 60 located indoors to receive the radio waves. Note that the communication unit that radiates the radio waves relayed indoors by the relay unit 211B is not limited to Bluetooth, and may be Wi-Fi or the like.

[0139] The LNA 213 is provided between the switch 212 and the mixer 214, and amplifies the radio waves received by the antenna 110 and outputs them while preventing degradation of the signal-to-noise ratio.

[0140] The mixer 214 demodulates the radio wave output from the LNA 213 by mixing it with a local signal (LO) and outputs an intermediate frequency (IF) signal. By converting the signal into an IF signal, digital conversion can be easily performed by the ADC 215.

[0141] The ADC 215 converts the IF signal output from the mixer 214 into a digital signal and outputs the digital signal to the wireless module 211 .

[0142] When the wireless communication device 200 transmits a signal from the antenna 110 , the DAC 216 converts the signal output by the wireless module 211 into an analog signal and outputs the IF signal to the mixer 217 .

[0143] The mixer 217 mixes the IF signal with a local signal (LO) to modulate it, and outputs the modulated signal to the PA 218 .

[0144] The PA 218 amplifies the signal output from the mixer 217 and outputs the amplified signal to the antenna 110 via the switch 212 .

[0145] When the radio waves handled by radio device 210 are Sub-6, radio device 210 may not include mixers 214 and 217. In this case, the signal input to ADC 215 and the signal output from DAC 216 are not IF signals but signals in the Sub-6 frequency band.

[0146] <Effects> The antenna device 100 includes a flexible spacer 130A that is attached to the main surface of the window glass 12 with an adhesive layer 135A, an antenna 110 that is arranged facing the main surface of the window glass 12, and a holder 130B that is attached to the spacer 130A and holds the antenna 110. Therefore, the spacer 130A can be adhered to the main surface of the window glass 12 without creating air bubbles between the adhesive layer 135A and the main surface of the window glass 12, and falling of the antenna device 100 can be prevented. The flexible spacer 130A has a simple configuration.

[0147] Therefore, it is possible to provide the antenna device 100 that can achieve fall prevention with a simple configuration.

[0148] Furthermore, the spacer 130A may be a plate-like body. The holder 130B can be stably attached to the spacer 130A, which is a plate-like body with a simple configuration, and it is possible to provide the antenna device 100 that can prevent the antenna 110 from falling with a simple configuration and can stably hold the antenna 110.

[0149] Furthermore, where t is the thickness of spacer 130A and E is the Young's modulus of spacer 130A, t is between 0.1 mm and 5 mm, and E is between 1 GPa and 10 GPa. That is, t × E may be between 0.1 GPa·mm and 50 GPa·mm. By attaching spacer 130A, which is flexible enough for a user to bend it by hand, to the main surface of window glass 12 with adhesive layer 135A while bending it, spacer 130A can be more reliably bonded to the main surface of window glass 12 without generating air bubbles between adhesive layer 135A and the main surface of window glass 12. Therefore, it is possible to provide antenna device 100 that can more reliably achieve fall prevention with a simple configuration.

[0150] Furthermore, the spacers 130A may be provided along at least two sides of the holder 130B in a plan view, so that the spacers 130A can stably hold the holder 130B.

[0151] Moreover, the holder 130B is detachably coupled to the spacer 130A, and the coupling force between the spacer 130A and the holder 130B may be smaller than the breaking force of the holder 130B. When the transmission cable 170 is pulled, the holder 130B comes off the spacer 130A before the joint between the holder 130B and the transmission cable 170 is damaged. Therefore, when the window glass 12 is opened, the holder 130B can be removed from the spacer 130A without damaging the joint between the holder 130B and the transmission cable 170.

[0152] The spacer 130A and the holder 130B may be coupled together by magnetic force, fitting force, or engagement force. The spacer 130A and the holder 130B can be detachably coupled together with a simple structure.

[0153] The antenna 110 may further include a matching layer 120 disposed between the antenna 110 and the window glass 12. The electrical length of the radio wave incident on the antenna 110 can be adjusted to match impedance.

[0154] The antenna 110 may be a patch antenna, a monopole antenna, a dipole antenna, or a spiral antenna. The antenna 110 can be realized with various types of antennas, and the antenna device 100 can be provided with a simple configuration and can achieve fall prevention.

[0155] The antenna 110 may further include a reflector 140 provided on the opposite side of the window glass 12. This can reflect radio waves emitted from the antenna 110 on the opposite side of the window glass 12 back toward the window glass 12, thereby improving communication conditions with the outdoor base station BS.

[0156] Furthermore, the window glass 12 can be opened and closed, and the holder 130B is coupled to the spacer 130A when the window glass 12 is in a first position where it is closed, and is detached from the spacer 130A when the window glass 12 is in a second position where it is open. When the window glass 12 moves to the second position, the holder 130B is detached from the spacer 130A, thereby providing an antenna device 100 that is capable of communication even when the window glass 12 is open. Furthermore, because the spacer 130A and the holder 130B are detachable, when the window glass 12 is closed, the holder 130B can be coupled to the spacer 130A again, and communication is possible even when the window glass 12 is opened and then closed again, making it possible to provide an antenna device 100 that is simple in configuration and can be prevented from falling.

[0157] The operating frequency of the antenna 110 may be a frequency included in the Sub-6 band or the millimeter wave band, making it possible to provide an antenna device 100 that is capable of transmitting and receiving radio waves in the Sub-6 or millimeter wave band and that can achieve fall prevention with a simple configuration.

[0158] The wireless communication device 200 includes the above-described antenna device 100, a transmission cable 170 (transmission path) connected to the antenna 110, and a wireless device 210 connected to the antenna 110 via the transmission cable 170. This allows the spacer 130A to be adhered to the main surface of the window glass 12 without creating air bubbles between the adhesive layer 135A and the main surface of the window glass 12, thereby preventing the antenna device 100 from falling. The flexible spacer 130A has a simple configuration.

[0159] Therefore, it is possible to provide a wireless communication device 200 that can prevent the device from falling with a simple configuration.

[0160] Furthermore, transmission cable 170 has a first end connected to holder 130B and a second end connected to wireless device 210. Holder 130B is detachably coupled to spacer 130A, and the coupling force between spacer 130A and holder 130B may be smaller than the tensile strength of transmission cable 170 and smaller than the bonding force between the first end of transmission cable 170 and holder 130B. When window glass 12 on the -X direction side is moved in the +X direction, holder 130B is detached from spacer 130A when window glass 12 moves to the position shown in FIG. 6B . At this time, holder 130B can be detached from spacer 130A without damaging the joint between transmission cable 170 and holder 130B, allowing repeated attachment and detachment of spacer 130A and holder 130B.

[0161] The coaxial cable 171M may further include a metal wire 172M extending along the coaxial cable 171M to reinforce the coaxial cable 171M. This makes it possible to provide a wireless communication device 200 that can more reliably prevent damage to the coaxial cable 171M and can achieve drop prevention with a simple configuration.

[0162] Furthermore, metal wire 172M may be connected to holder 130B and housing 210A of wireless device 210. When metal wire 172M is fully stretched between holder 130B and housing 210A, holder 130B is detached from spacer 130A, which makes it possible to more reliably prevent damage to coaxial cable 171M.

[0163] Furthermore, the length between holder 130B of metal wire 172M and housing 210A of wireless device 210 may be shorter than the length between holder 130B of coaxial cable 171M and housing 210A of wireless device 210. When window glass 12 on the −X direction side is moved in the +X direction, fully stretched metal wire 172M pulls holder 130B and comes off spacer 130A, and in this state, coaxial cable 171M is not fully stretched, so damage to coaxial cable 171M can be more reliably prevented.

[0164] Furthermore, the wireless device 210 may be installed in the window frame 11 of the window 10 in which the window glass 12 is provided, or in a structure surrounding the window frame 11. The length of the transmission cable 170 can be shortened, and the wireless communication device 200 with reduced transmission loss in the transmission cable 170 can be provided.

[0165] The above describes exemplary antenna devices and wireless communication devices of the present disclosure, but 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.

[0166] This international application claims priority based on Japanese Patent Application No. 2023-102222, filed on June 22, 2023, the entire contents of which are incorporated herein by reference.

[0167] REFERENCE SIGNS LIST 1 Building 1A Wall 10 Window 11 Window frame 12 Window glass 100 Antenna device 110 Antenna 120 Matching layer 130 Frame 130A, 130MA Spacer 130B Holder 130B1 First holder 130B2 Second holder 131A Joining portion 131B Joining portion 135A Adhesive layer (an example of an adhesive) 140 Reflector (an example of a reflecting portion) 170 Transmission cable (an example of a transmission path) 171M Coaxial cable (an example of a transmission path) 172M Metal wire (an example of a reinforcing member) 200 Wireless communication device 210 Wireless device (an example of a wireless communication portion)

Claims

1. An antenna device comprising: a flexible spacer affixed to a main surface of a window glass with an adhesive; an antenna positioned opposite the main surface of the window glass; and a holding member attached to the spacer and holding the antenna.

2. The antenna device according to claim 1, wherein the spacer is a plate-like body.

3. An antenna device as described in claim 1 or 2, wherein, assuming that the plate thickness of the spacer is t and the Young's modulus of the spacer is E, t is 0.1 mm or more and 5 mm or less, E is 1 GPa or more and 10 GPa or less, and t x E is 0.1 GPa·mm or more and 50 GPa·mm or less.

4. The antenna device according to any one of claims 1 to 3, wherein the spacer is provided along at least two sides of the holding member in a plan view.

5. An antenna device according to any one of claims 1 to 4, wherein the holding member is detachably connected to the spacer, and the bonding strength between the spacer and the holding member is smaller than the destructive strength of the holding member.

6. The antenna device according to any one of claims 1 to 5, wherein the spacer and the holding member are joined together by magnetic force, fitting force, or engagement force.

7. An antenna arrangement according to any one of claims 1 to 6, further comprising a matching layer disposed between said antenna and said window pane.

8. The antenna device according to any one of claims 1 to 7, wherein the antenna is a patch antenna, a monopole antenna, a dipole antenna, or a spiral antenna.

9. The antenna device according to any one of claims 1 to 8, further comprising a reflector provided on the opposite side of said antenna to said window glass.

10. The antenna device according to claim 5, wherein the window glass is openable and closable, and the retaining member is coupled to the spacer when the window glass is in a first closed position and detached from the spacer when the window glass is in a second open position.

11. An antenna device according to any one of claims 1 to 10, wherein the operating frequency of the antenna is a frequency included in the Sub-6 band or the millimeter wave band.

12. A wireless communication device comprising: an antenna device according to any one of claims 1 to 11; a transmission path connected to said antenna; and a wireless communication unit connected to said antenna via said transmission path.

13. The wireless communication device described in claim 12, wherein the transmission path has a first end connected to the holding member and a second end connected to the wireless communication unit, the holding member is removably connected to the spacer, and the bonding strength between the spacer and the holding member is smaller than the tensile strength of the transmission path and smaller than the bonding strength between the first end of the transmission path and the holding member.

14. The wireless communication device according to claim 12 or 13, further comprising a reinforcing member extending along said transmission line and reinforcing said transmission line.

15. The wireless communication device according to claim 14, wherein the reinforcing member is connected to the holding member and to a housing of the wireless communication unit.

16. The wireless communication device according to claim 15, wherein the length of the reinforcing member between the holding member and the housing of the wireless communication unit is shorter than the length of the transmission path between the holding member and the housing of the wireless communication unit.

17. The wireless communication device according to any one of claims 12 to 16, wherein the wireless communication unit is installed in a window frame in which the window glass is provided, or in a structure surrounding the window frame.

Images