Antenna device, and wireless communication device

Abstract

Provided is an antenna device capable of achieving a reduction in height in a state of being attached to a window glass.　This antenna device includes: an antenna attached to a main surface of an indoor side of a window glass, the antenna having a first substrate and an antenna element provided on the first substrate; a holding unit attached to the main surface of the indoor side of the window glass or the antenna; and a power supply unit held by the holding unit, the power supply unit having a second substrate, a ground layer provided on a first surface on the antenna side of the second substrate, a slot antenna formed in the ground layer and coupled with the antenna element, and a power supply line that is provided on a second surface of the second substrate and that supplies power to the slot antenna.

Description

Antenna device and wireless communication device

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

[0002] Conventionally, there has been an antenna device including a first transparent dielectric panel located on the transmitting and receiving side of radio waves, an antenna element superimposed on the first transparent dielectric panel via an intermediate layer (substrate), a first glass substrate superimposed on the antenna element, a second glass plate provided with a gap between it and the first glass substrate or with an intermediate panel between it and the first glass plate, and a power supply unit having a ground layer superimposed on the second glass plate via the intermediate layer (substrate) (see, for example, Patent Document 1).

[0003] International Publication No. 2022 / 101498

[0004] Conventional antenna devices include a first transparent dielectric panel and an intermediate layer (substrate) located on the radio wave transmitting / receiving side of the antenna element, resulting in a large overall thickness. The first transparent dielectric panel is particularly thick, even among conventional antenna devices. Therefore, when the first transparent dielectric panel is attached to a window glass, it protrudes significantly from the window glass. Because of this large protrusion from the window glass, conventional antenna devices have been unable to achieve a low profile.

[0005] Therefore, an object of the present invention is to provide an antenna device and a wireless communication device that can be made low-profile when attached to a window glass.

[0006] An antenna device according to an embodiment of the present disclosure includes an antenna that is affixed to the indoor main surface of a window glass, the antenna having a first substrate and an antenna element provided on the first substrate; a holder that is attached to the indoor main surface of the window glass or the antenna; and a power supply unit that is held by the holder, the power supply unit having a second substrate, a ground layer provided on a first surface of the second substrate on the antenna side, a slot antenna formed on the ground layer and coupled to the antenna element, and a power supply line that is provided on the second surface of the second substrate and supplies power to the slot antenna.

[0007] It is possible to provide an antenna device and a wireless communication device that can be made low-profile when attached to a window glass.

[0008] 2B is a diagram showing an example of a building in which a wireless communication device including an antenna device according to an embodiment is installed, from the side; FIG. 2C is a diagram showing an example of the configuration of an antenna device and a window according to an embodiment; FIG. 2D is a diagram showing an example of the configuration of an antenna device and a window according to an embodiment; FIG. 2E is a diagram showing an example of a cross section taken along the arrows B-B in FIG. 2B and an example of the configuration of the half of the antenna device on the -X direction side according to an embodiment; FIG. 2F is a diagram showing an example of the configuration of an antenna and a power supply unit of the antenna device according to an embodiment in detail; FIG. 2G is a diagram showing an example of an antenna device according to an embodiment in a YZ plane view; FIG. 2H is a diagram showing an example of a simulation result (Part 1) of the gain frequency characteristic of the antenna device according to an embodiment; FIG. 2I is a diagram showing an example of an antenna device according to an embodiment in a YZ plane view; FIG. 2J is a diagram showing an example of a simulation result (Part 2) of the gain frequency characteristic of the antenna device according to an embodiment; FIG. 2I is a diagram showing an example of an antenna device according to an embodiment including an adjustment plate in a YZ plane view; FIG. 2J is a diagram showing an example of a simulation result (Part 3) of the gain frequency characteristic of the antenna device according to an embodiment including an adjustment plate; FIG. 2H is a diagram showing an example of the configuration of an antenna device according to a first modified example of an embodiment; FIG. 2I is a diagram showing an example of the configuration of an antenna device according to a second modified example of an embodiment; FIG. 2I is a diagram showing an example of the configuration of an antenna device according to a third modified example of an embodiment; FIG. 2I is a diagram showing an example of the configuration of an antenna device according to a fourth modified example of an embodiment. Fig. 10 is a diagram showing an example of the configuration of an antenna device according to a fifth modified example of an embodiment; Fig. 11 is a cross-sectional view showing an example of the configuration of a part of a holder of the antenna device according to the fifth modified example of an embodiment; Fig. 12 is a diagram showing an example of the configuration of an antenna device according to a sixth modified example of an embodiment; Fig. 13 is a diagram showing an example of the configuration of an antenna device according to a seventh modified example of an embodiment;

[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] 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, a planar view refers to a view from the XY plane. In addition, in the following, 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., 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." In addition, in the following, when referring to "millimeter waves" or "millimeter wave band," this includes not only the frequency band of 30 GHz to 300 GHz, but also the quasi-millimeter wave band of 24 GHz to 30 GHz.

[0012] <Outline of Antenna Device 100 and Wireless Communication Device 200> FIG. 1 is a diagram showing an example of a building 1 in which a wireless communication device 200 including an antenna device 100 according to an embodiment is installed, as viewed from the side.

[0013] The wireless communication device 200 includes the antenna device 100 and a communication device 180. The communication device 180 is connected to the transmission cable 140 of the antenna device 100.

[0014] 1 shows an outdoor base station BS and a smartphone 30 in addition to a building 1 and a wireless communication device 200. The base station BS is an example of an external device located outside the building 1. Although FIG. 1 shows a base station BS, the external device of the wireless communication device 200 may be a relay station. Even if the external device of the wireless communication device 200 is a relay station, the wireless communication device 200 will communicate with the base station via the relay station.

[0015] Unless otherwise specified, the following description of the operation and configuration of wireless communication device 200 will focus on the operation of receiving radio waves by wireless communication device 200. Because the operation of wireless communication device 200 to transmit radio waves is the opposite of the operation of receiving radio waves, a description of the operation of wireless communication device 200 to transmit radio waves may be omitted.

[0016] 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 windowpane 11 and a window frame (the window frame on the building 1 side). The wireless communication device 200 is installed inside the building 1, for example, and functions as a repeater that relays radio waves arriving from the outside to the inside and relays radio waves from the inside to the outside. Note that, here, a configuration in which the wireless communication device 200 is installed inside the building 1 will be described as an example.

[0017] 1, the XYZ coordinate system is defined, for example, with reference to the indoor main surface of the window glass 11. The window glass 11 may be either single-pane glass or double-glazed glass. The indoor main surface of the window glass 11 that serves as the reference for the XYZ coordinate system is the main surface on the +Z direction side, and the outdoor main surface of the window glass 11 is the main surface on the -Z direction side. The +Z direction side main surface of the window glass 11 and the outdoor side main surface of the window glass 11 are parallel to the XY plane. The building 1 has a wall 1W on the -Z direction side that is parallel to the XY plane, and the window 10 is provided in the wall 1W.

[0018] The radio waves relayed by the wireless communication device 200 including the antenna device 100 are preferably radio waves in the frequency band of 0.7 GHz to 40 GHz, including the Sub-6 frequency band and the millimeter wave band of the fifth generation mobile communication system (5G). The wireless communication device 200 relays radio waves arriving from an outdoor base station BS or the like indoors. The wireless communication device 200 may also have a function to receive radio waves arriving from a base station BS or the like, convert them into radio waves of a communication standard different from that of the radio waves arriving from the base station BS or the like, and relay them indoors.

[0019] The radio waves relayed by wireless communication device 200 may be Long Term Evolution (LTE), LTE-Advanced (LTE-A), Ultra Mobile Broadband (UMB), or Citizens Broadband Radio Service (CBRS). The radio waves relayed by wireless communication device 200 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.

[0020] Here, as an example, a case will be described where radio waves transmitted and received by the base station BS do not penetrate the wall 1W of the building 1. The reason why radio waves do not penetrate the wall 1W of the building 1 is because the frequency of the radio waves is relatively high. The boundary frequency between the frequency of radio waves that penetrates the wall 1W of the building 1 and the frequency of radio waves that do not penetrate the wall 1W of the building 1 depends on the material and structure of the wall 1W, but as an example, it is about 0.7 GHz to 3 GHz.

[0021] When radio waves do not penetrate the wall 1W of the building 1, this does not only mean that the radio waves do not penetrate the wall 1W at all, but also means that the radio waves that penetrate the wall 1W are so weak that they do not have sufficient radio wave strength for practical use to communicate using terminals such as a smartphone 30 or a PC (Personal Computer) inside (indoors) the wall 1W of the building 1.

[0022] Radio waves transmitted from the base station BS do not penetrate the wall 1W of the building 1, but penetrate only the window glass 11 of the window 10 to enter the building. Because the radio waves transmitted from the base station BS have high linearity, they only reach the line of sight (LOS) area of ​​the window 10, which makes it easy for blind zones to form inside the building. The window glass 11 of the window 10 is an entrance into the building 1 for radio waves transmitted from the base station BS. Radio waves arriving at the building 1 from the base station BS and passing through the window glass 11 include direct waves that arrive directly from the base station BS to the building 1, and reflected waves that arrive after being reflected by the walls of other buildings or the like along the way. The line of sight area of ​​the window 10 is the area where such direct waves or reflected waves penetrate the window 10 and enter the building 1.

[0023] Here, we will explain a case where radio waves transmitted from the base station BS enter the building 1 by passing only through the window glass 11 without passing through the wall 1W of the building 1. The lower limit of the frequency of such radio waves is, for example, about 0.7 GHz to 3 GHz.

[0024] The antenna device 100 and the wireless communication device 200 are preferably used when radio waves transmitted from the base station BS enter the building by passing only through the window glass 11 without passing through the wall 1W of the building 1. However, the antenna device 100 and the wireless communication device 200 may also be used when radio waves transmitted from the base station BS pass through the wall 1W of the building 1. This is because even in such a case, the loss of radio waves passing through the window glass 11 is smaller than the loss of radio waves passing through the wall 1W, and radio waves of higher intensity can be received.

[0025] Since the wireless communication device 200 transmits and receives radio waves to and from the base station BS, the antenna device 100 is provided on the indoor main surface of the window glass 11 of the window 10. The antenna device 100 has an antenna. A transmission cable 140 connects the antenna of the antenna device 100 to the communication device 180. The antenna device 100 may also include multiple antennas. In this case, one transmission cable 140 may be connected to each antenna. The configuration of the antenna device 100 will be described later using Figures 2A to 3B.

[0026] As an example, the wireless communication device 200 performs amplification processing, or amplification processing and frequency conversion processing, on the radio waves received by the antenna device 100, and outputs the radio waves indoors from an antenna (not shown) or the like provided in the communication device 180. By outputting radio waves indoors from the wireless communication device 200, it becomes possible to easily receive the radio waves at a terminal such as a smartphone 30 or a PC indoors.

[0027] <Configuration of the window 10> In the following, an example will be described in which the window 10 is a sliding window that can be opened and closed, but the window 10 may also be a casement window or a fixed window. Furthermore, the window glass 11 held by the window frame 12 may be one or more panes of glass.

[0028] As shown in Fig. 3A, the window glass 11 has a main surface 11A facing the indoor side (+Z direction) and a main surface 11B facing the outdoor side (-Z direction). The window glass 11 may be made of commonly available glass, such as soda-lime glass, alkali-free glass, Pyrex (registered trademark) glass, or quartz glass. The window glass 11 is not limited to a glass plate, and may also be made of a resin surface material such as polycarbonate or acrylic.

[0029] 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. The window glass 11 and window frame 12 of the window 10 are provided on a wall 1W that is perpendicular to the horizontal plane.

[0030] 2A and 2B are diagrams showing an example of the configuration of the antenna device 100 and the window 10. The antenna device 100 is attached to the window 10. The window 10 includes a window glass 11 and a window frame 12. The antenna device 100 includes an antenna 110, a power supply unit 120, a holder 130, and a transmission cable 140 (see FIG. 1).

[0031] Fig. 2A shows the state before the power supply unit 120 and holder 130 are attached to the antenna 110, and Fig. 2B shows the state after the power supply unit 120 and holder 130 are attached to the antenna 110. The antenna device 100 will be described using Figs. 3A and 3B in addition to Figs. 2A and 2B. Fig. 3A is a diagram showing a cross section taken along the arrow B-B in Fig. 2B and an example of the configuration of the half of the antenna device 100 on the -X direction side. Fig. 3B is a diagram showing in detail an example of the configuration of the antenna 110 and power supply unit 120. Note that the transmission cable 140 is omitted from Figs. 2A to 3B.

[0032] <Low Profile> The antenna device 100 has a configuration in which the protrusion in the +Z direction from the indoor main surface of the window glass 11 is reduced when the antenna device 100 is attached to the indoor main surface of the window glass 11. Reducing the protrusion of the antenna device 100 in the +Z direction from the indoor main surface of the window glass 11 reduces the profile of the antenna device 100. A low profile means that the protrusion in the +Z direction from the indoor main surface of the window glass 11 is small.

[0033] 2A, the antenna 110 is attached to the main surface 11A of the window glass 11. The antenna 110 has a substrate 111 and an antenna element 112. The substrate 111 is an example of a first substrate.

[0034] <Substrate 111> The substrate 111 is, for example, a resin substrate, and is preferably transparent. "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. Examples of resin materials that satisfy this condition include acrylic resins such as polymethyl methacrylate, cycloolefin resins, polycarbonate resins, and polyethylene terephthalate (PET). The substrate 111 may also be made of transparent glass. The transparency of the substrate 111 can reduce obstruction of the view through the window glass 11.

[0035] <Antenna Element 112> As an example, the antenna element 112 is provided on the surface of the substrate 111 on the +Z direction side. As an example, the antenna element 112 is coupled to a ground layer 122 (described later) to form a patch antenna. The patch antenna is capable of radiating radio waves in a direction from the ground layer 122 toward the antenna element 112. The antenna element 112 is not limited to a square shape in a plan view, and may also be rectangular. In other words, the shape of the antenna element 112 in a plan view may be rectangular.

[0036] As an example, the antenna element 112 is arranged symmetrically with respect to a line parallel to the X-axis that passes through the center of the Y-direction width of the substrate 111 in a planar view, and with respect to a line parallel to the Y-axis that passes through the center of the X-direction length of the substrate 111 in a planar view.

[0037] The shape of the antenna element 112 is not limited to a square, and may be a polygon having five or more sides, a circle, etc. The antenna element 112 may be provided on the surface on the −Z direction side of the substrate 111. The antenna 110 may have multiple antenna elements 112.

[0038] If the substrate 111 is transparent to visible light, it is preferable from the viewpoint of visibility that the antenna element 112 be formed from a transparent conductor such as a mesh-like thin metal film made of copper, nickel, gold, or the like.

[0039] The antenna element 112 is made of zinc oxide (ZnO), tin oxide (SnO ２ The transparent conductive film may be formed of 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 film for low-e (low emissivity) glass.

[0040] As described above, when the substrate 111 is transparent to visible light and the antenna element 112 is made of a transparent conductor such as a mesh-like metal thin film, the antenna 110 only needs to have a visual transmittance of 50% or more.

[0041] <Power supply unit 120> As shown in Fig. 2A, power supply unit 120 is attached to holder 130, and as shown in Fig. 2B, holder 130B is fixed to antenna 110, so that power supply unit 120 faces antenna 110 as shown in Fig. 3A. Fig. 3B shows antenna 110 and power supply unit 120 in a state in which holder 130 is fixed to antenna 110, with holder 130 omitted.

[0042] The power supply unit 120 includes a substrate 121, a ground layer 122, a slot antenna 122A, and a power supply line 123. The substrate 121 is an example of a second substrate.

[0043] <Substrate 121> The substrate 121 is, for example, a resin substrate, and is preferably transparent. The meaning of "transparent" is the same as that of the substrate 111. Transparent resin materials from which the substrate 121 can be made include acrylic resins such as polymethyl methacrylate, cycloolefin resins, polycarbonate resins, polyethylene terephthalate (PET), and the like. The substrate 121 may also be made of transparent glass. The transparency of the substrate 121 can reduce obstruction of the view through the window glass 11.

[0044] <Ground Layer 122> As an example, the ground layer 122 is formed over substantially the entire surface on the −Z direction side of the substrate 121, and a slot antenna 122A is formed in the center in a plan view. The ground layer 122 is electromagnetically coupled to the antenna element 112, and together with the antenna element 112, forms a patch antenna. The ground layer 122 is connected to the ground potential point of the communication device 180 via the ground line of the transmission cable 140.

[0045] If the substrate 121 is transparent to visible light, it is preferable from the viewpoint of visibility that the ground layer 122 be formed from a transparent conductor such as a mesh-like thin metal film made of copper, nickel, gold, or the like.

[0046] The ground layer 122 is made of zinc oxide (ZnO), tin oxide (SnO ２The transparent conductive film may be formed of 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 film for low-e (low emissivity) glass.

[0047] <Slot Antenna 122A> The slot antenna 122A is, for example, a rectangular slot formed in the center, in plan view, of the ground layer 122. The slot antenna 122A is located inside the outer edge of the antenna element 112, in plan view.

[0048] As an example, the slot antenna 122A is provided line-symmetrically with respect to a line parallel to the X axis that passes through the center of the Y-direction width of the ground layer 122 in a plan view, and line-symmetrically with respect to a line parallel to the Y axis that passes through the center of the X-direction length of the ground layer 122 in a plan view. Therefore, the slot antenna 122A is located at the center of the antenna element 112 in the X direction in a plan view.

[0049] The slot antenna 122A is arranged so that, in the X direction, the distance between the outer edge of the slot antenna 122A on the +X direction side and the outer edge of the antenna element 112 on the +X direction side is equal to the distance between the outer edge of the slot antenna 122A on the −X direction side and the outer edge of the antenna element 112 on the −X direction side. Furthermore, the slot antenna 122A is arranged so that, in the Y direction, the distance between the outer edge of the slot antenna 122A on the +Y direction side and the outer edge of the antenna element 112 on the +Y direction side is equal to the distance between the outer edge of the slot antenna 122A on the −Y direction side and the outer edge of the antenna element 112 on the −Y direction side.

[0050] The longitudinal direction of the slot antenna 122A is, for example, the Y direction. For example, the slot antenna 122A is formed so that the shape is symmetrical in the Y direction with respect to the center of the width of the ground layer 122 in the Y direction at the center of the length of the ground layer 122 in the X direction.

[0051] The slot antenna 122A is a long, narrow opening provided in the ground layer 122. The slot antenna 122A is electromagnetically coupled to the antenna element 112 and also to a power feed line 123 having a tip 123A. The slot antenna 122A is fed with power from the tip 123A of the power feed line 123, and is excited in the short direction (X direction), and radiates the power fed from the tip 123A to the antenna element 112.

[0052] If the antenna 110 has multiple antenna elements 112, the ground layer 122 may have multiple slot antennas 122A corresponding to the multiple antenna elements 112. The positional relationship between each slot antenna 122A and each antenna element 112 may be the same as the positional relationship between the antenna element 112 and the slot antenna 122A described above. The multiple slot antennas 122A may also include a slot antenna 122A whose longitudinal direction is in the Y direction and a slot antenna 122A whose longitudinal direction is in the X direction. In this case, the antenna device 100 can emit radio waves with different polarization directions.

[0053] <Feeder Line 123> As an example, the feeder line 123 is formed on the surface of the substrate 121 on the +Z direction side, and extends in the −X direction from the end of the substrate 121 on the +X direction side at the center of the width of the substrate 121 in the Y direction. As an example, the tip 123A on the −X direction side of the feeder line 123 is located on the −X direction side of the slot antenna 122A in a planar view, and overlaps with a portion of the ground layer 122 on the −X direction side of the slot antenna 122A. Therefore, the portion of the feeder line 123 excluding the portion overlapping with the slot antenna 122A in a planar view overlaps with the ground layer 122 in a planar view, forming a microstrip line. A portion of the feeder line 123 on the +X direction side of the tip 123A overlaps with the slot antenna 122A in a planar view. The feeder line 123 is located at the center of the length of the slot antenna 122A in the Y direction in a planar view. In FIG. 3B , as an example, the power supply line 123 extends in the −X direction from the end of the substrate 121 on the +X direction side in a plan view, but may also extend in the +X direction from the end of the substrate 121 on the −X direction side.

[0054] The power feeder 123 is connected to the communication device 180 via a signal line of the transmission cable 140. The power feeder 123 supplies power supplied from the communication device 180 to the slot antenna 122A. Then, the slot antenna 122A radiates radio waves, thereby feeding power to the antenna element 112.

[0055] As an example, the power supply line 123 and the ground layer 122 may be connected to a signal terminal and a ground terminal of a connector connected to the end of the transmission cable 140, respectively.

[0056] <Holder 130> The holder 130 has holder portions 131 and 132. The holder 130 is, for example, a wall member having a rectangular ring shape (frame shape) in a plan view, and has an opening 133 in the center in a plan view.

[0057] The holder portions 131 and 132 are configured by dividing the holder 130 in two in the Z direction. Therefore, the holder portions 131 and 132 also have a rectangular ring shape (frame shape) in a plan view and have an opening in the center. As an example, the holder portion 131 is located on the −Z direction side, and the holder portion 132 is located on the +Z direction side. The position at which the holder 130 is divided into the holder portions 131 and 132 in the Z direction may be the center in the Z direction as shown in FIG. 3A , or may be a position shifted from the center in the Z direction toward the +Z direction or the −Z direction.

[0058] The opening 133 of the holder 130 is rectangular and larger than the outer edge of the antenna element 112 in a plan view, and contains the antenna element 112 in a plan view in order to suppress the influence on the coupling between the antenna element 112 and the power supply part 120.

[0059] The holder parts 131 and 132 are configured to hold the power supply part 120 at the joint of their inner edges in a plan view. The holder parts 131 and 132 are fixed to each other while being aligned with each other as shown in Fig. 3A. The holder parts 131 and 132 may be fixed with an adhesive or the like, or may be fixed by a mechanical engagement structure such as a snap fit. As an example, the holder 130 is configured so that the interior is hollow when the holder parts 131 and 132 are joined together.

[0060] The holder 130 is preferably made of resin, for example, and is transparent. The meaning of "transparent" is the same as that of the substrate 111, etc. Transparent resin materials from which the holder 130 can be made include acrylic resins such as polymethyl methacrylate, cycloolefin resins, polycarbonate resins, polyethylene terephthalate (PET), etc. The transparency of the holder 130 can reduce obstruction of the view of the window glass 11.

[0061] 3A shows the holder 130 having a rectangular ring shape in a plan view, but the shape of the holder 130 in a plan view is not limited to a rectangular ring shape. The holder 130 may be a wall member provided on two opposing sides of the four sides of the outer edge of the substrate 111 in a plan view, or on three of the four sides of the outer edge of the substrate 111. Furthermore, the holder 130 does not have to be a wall-shaped wall member, and may be, for example, a plurality of columnar members provided along the outer edge of the substrate 111.

[0062] <Transmission Cable 140> The transmission cable 140 connects the antenna 110 and the communication device 180. When there are multiple antennas 110, one transmission cable 140 may be connected to each antenna 110. The transmission cable 140 is configured as a coaxial cable, for example. Note that instead of a coaxial cable, a waveguide or a transmission path such as a microstrip line or a coplanar waveguide formed on a flexible substrate or the like may be used as the transmission cable 140. The transmission cable 140 has a signal line and a ground line.

[0063] <Relationship Between the Distance Between the Antenna Element 112 and the Slot Antenna 122A and the Thickness of the Window Glass 11> Figure 4A is a diagram showing an example of the antenna device 100 as viewed in the YZ plane. Figure 4A shows a simplified version of the antenna device 100. The thickness of the window glass 11 is denoted by t (mm). Although Figure 4A does not show the antenna element 112 or the ground layer 122, the antenna element 112 is provided on the surface of the substrate 111 of the antenna 110 (see Figure 3B) on the +Z direction side, and the ground layer 122 is provided on the surface of the substrate 121 of the power supply unit 120 (see Figure 3B) on the -Z direction side. Therefore, the gap G (mm) between the surface of the antenna 110 on the +Z direction side and the surface of the power supply unit 120 on the -Z direction side corresponds to the distance between the antenna element 112 and the slot antenna 122A. Hereinafter, this gap G will be referred to as the gap G between the antenna element 112 and the slot antenna 122A.

[0064] Antenna 110 is attached to window glass 11 and transmits and receives radio waves via the dielectric material of window glass 11, so the radiation characteristics of the radio waves change depending on gap G. This is because the degree of the effect of shortening the wavelength of the radio waves changes depending on the effective relative dielectric constant, which is determined by the thickness t of window glass 11, the relative dielectric constant of window glass 11, and the gap G where air exists.

[0065] Therefore, there is an optimum value for the gap G relative to the thickness t of the window glass 11. As an example, when the thickness t of the window glass 11 is 6 mm, the optimum value for the gap G is 4 mm.

[0066] <Simulation Results (Part 1)> Fig. 4B is a diagram showing an example of simulation results (Part 1) of the gain frequency characteristics of the antenna device 100. Fig. 4B shows the gain frequency characteristics (solid line) when the thickness t of the window glass 11 is 6 mm and the gap G is 4 mm, and the gain frequency characteristics (dashed line) when the thickness t of the window glass 11 is 3 mm and the gap G is 4 mm.

[0067] As shown by the solid line, the frequency characteristics of the gain when the thickness t of the window glass 11 is 6 mm show that a frequency band in which the gain is 6 dBi or more is obtained from 3.0 GHz to 4.1 GHz.

[0068] Furthermore, as shown by the broken line, the frequency characteristics of the gain when the thickness t of the window glass 11 is 3 mm do not provide a frequency band in which the gain is 6 dBi or more, and the frequency is generally shifted to the high frequency side.

[0069] Fig. 5A is a view showing an example of the antenna device 100 as seen in the YZ plane. Like Fig. 4A, Fig. 5A shows a simplified version of the antenna device 100. The thickness t (mm) of the window glass 11 and the gap G (mm) between the antenna element 112 and the slot antenna 122A are also the same as those in Fig. 4A.

[0070] In FIG. 5A, the thickness t of the window glass 11 is 3 mm, and the optimum value of the gap G is 6 mm.

[0071] <Simulation Results (Part 2)> Fig. 5B is a diagram showing an example of simulation results (Part 2) of the gain frequency characteristics of the antenna device 100. Fig. 5B shows the gain frequency characteristics (dashed line) when the thickness t of the window glass 11 is 3 mm and the gap G is 4 mm, and the gain frequency characteristics (solid line) when the thickness t of the window glass 11 is 3 mm and the gap G is 6 mm. Note that the gain frequency characteristics shown by the dashed line are the same as the gain frequency characteristics shown by the dashed line in Fig. 4B.

[0072] In the gain frequency characteristics when the gap G is 4 mm, as shown by the dashed line, no frequency band with a gain of 6 dBi or more was obtained, whereas in the gain frequency characteristics when the gap G is 6 mm, as shown by the solid line, a frequency band with a gain of 6 dBi or more was obtained from 3.45 GHz to 4.5 GHz. In other words, by increasing the gap G, the gain was restored.

[0073] In this way, it was confirmed that the optimum value of the gap G varies depending on the thickness t of the window glass 11. Furthermore, from the characteristics of the solid lines shown in Fig. 4B and Fig. 5B, it was confirmed that as the thickness t of the window glass 11 becomes thinner, the optimum gap G becomes larger and the frequency band with high gain shifts to the higher frequency side.

[0074] Here, the shortening coefficient α of the wavelength of the radio wave due to the thickness t of the window glass 11, the relative dielectric constant of the window glass 11, and the effective relative dielectric constant of the air in the gap G is defined as α. The shortening coefficient α of the wavelength of the radio wave due to the effective relative dielectric constant varies depending on the thickness t of the window glass 11, and the thicker the window glass 11, the larger the shortening coefficient α. The shortening coefficient α is synonymous with the wavelength shortening rate, and takes a value in the range 0<α<1.

[0075] Here, the length of one side of the square antenna element 112 is L, and the effective length (electrical length) of the length L is Lg. Furthermore, the shortening coefficient when the thickness t of the window glass 11 is 6 mm is α1, and the shortening coefficient when the thickness t of the window glass 11 is 3 mm is α2. α1<α2 holds.

[0076] When the thickness t of the window glass 11 is 6 mm, the length L of one side of the antenna element 112 is expressed as the effective length Lg1 by the following equation (1): Lg1=L / α1 (1)

[0077] When the thickness t of the window glass 11 is 3 mm, the length L of one side of the antenna element 112 is expressed as the effective length Lg2 by the following equation (2): Lg2=L / α2 (2)

[0078] According to equations (1) and (2), Lg1 > Lg2, and therefore the resonant frequency f1 of the antenna element 112 when the thickness t of the window glass 11 is 6 mm is lower than the resonant frequency f2 of the antenna element 112 when the thickness t of the window glass 11 is 3 mm. In other words, the resonant frequency f2 of the antenna element 112 when the thickness t of the window glass 11 is 3 mm is higher than the resonant frequency f1 of the antenna element 112 when the thickness t of the window glass 11 is 6 mm. For these reasons, it is believed that as the thickness t of the window glass 11 becomes thinner, the optimal gap G becomes larger, and the frequency band with high gain shifts to the higher frequency side.

[0079] This frequency band shift is thought to be due in part to a change in the overall matching between antenna 110 and power supply 120 caused by an increase in gap G. In addition, in the simulation (part 1) shown in Figure 4B, the overall shift to higher frequencies when the thickness t of window glass 11 was reduced from 6 mm to 3 mm is thought to be due in part to a change in the overall matching between antenna 110 and power supply 120.

[0080] <Versatility of the Antenna Device 100> The antenna device 100 configured as described above has a low profile because it protrudes only slightly from the indoor main surface 11A of the window glass 11. If the operating frequency band of the antenna element 112 can be kept constant regardless of the thickness t of the window glass 11, the antenna device 100 can be attached to window glasses 11 of various thicknesses t, thereby increasing versatility.

[0081] For example, let us assume that the radio waves transmitted and received by the base station BS (see FIG. 1) are in the 3.7 GHz band, which is included in the Sub-6 band, and that the antenna element 112 is designed for the 3.7 GHz band. Also, let us assume that a user who purchases the antenna device 100 will install it on a windowpane 11 by themselves. Since users of various thicknesses will purchase the antenna device 100, it will be installed on windowpanes 11 of various thicknesses t.

[0082] In such a case, if the operating frequency band of the antenna element 112 can be adjusted to the 3.7 GHz band regardless of the thickness t of the window glass 11, the versatility of the antenna device 100 will be increased. Furthermore, since it becomes possible to use the antenna device 100 including the antenna element 112 designed for the 3.7 GHz band regardless of the thickness t of the window glass 11, the manufacturing cost of the antenna device 100 can be reduced, and users will benefit from a lower purchase price.

[0083] In order to achieve the high versatility described above, the antenna device 100 uses an adjustment plate as an example. Next, the adjustment plate will be described.

[0084] <Adjusting plate 150> Fig. 6A is a view showing an example of antenna device 100 including adjusting plate 150 as seen in the YZ plane. Like Fig. 4A, Fig. 6A shows antenna 110, power supply unit 120, and holder 130 in a simplified form. The thickness t (mm) of window glass 11 and the gap G (mm) between antenna element 112 and slot antenna 122A are also the same as Fig. 4A.

[0085] 6A includes an adjusting plate 150 provided between antenna 110 and power supply unit 120. More specifically, as an example, adjusting plate 150 is held by holder 130 so as to abut against the surface of antenna 110 on the +Z direction side. Adjusting plate 150 is held in holder 130 in a detachable manner.

[0086] Holder 130 may hold adjusting plate 150 in any configuration as long as adjusting plate 150 is detachable from holder 130. As an example, adjusting plate 150 may be configured to be insertable and detachable from holder 130, so that adjusting plate 150 is detachable from holder 130. For example, holder 130 may be provided with a groove or the like for inserting adjusting plate 150.

[0087] Note that adjustment plate 150 only needs to be held by holder 130 between antenna 110 and power supply unit 120, and does not have to be in contact with the surface on the +Z direction side of antenna 110. Adjustment plate 150 may also be in contact with the surface on the −Z direction side of power supply unit 120. Adjustment plate 150 may be provided with a gap between it and both antenna 110 and power supply unit 120.

[0088] Adjustment plate 150 is a dielectric plate-like member provided to adjust the electrical length of radio waves in antenna element 112. Adjustment plate 150 is preferably transparent when antenna 110, power supply unit 120, and holder 130 are transparent. "Transparent" means that the visual transmittance is at least 40% or more, preferably 60% or more, more preferably 70% or more, and even more preferably 80% or more.

[0089] Such a transparent adjustment plate 150 can be made of, for example, polycarbonate, acrylic, COP (cycloolefin polymer), PET (polyethylene terephthalate), polystyrene, glass, or the like.

[0090] By providing adjusting plate 150 between antenna 110 and power supply unit 120, antenna device 100 transmits and receives radio waves via a dielectric material called adjusting plate 150 in addition to window glass 11. Adjusting plate 150 is provided within gap G. Therefore, by providing adjusting plate 150 between antenna 110 and power supply unit 120, it is possible to change the effective relative dielectric constant, which is determined by the thickness of window glass 11, the relative dielectric constant of window glass 11, adjusting plate 150 provided in gap G, and gap G where air exists.

[0091] Such an adjustment plate 150 can adjust the electrical length of the radio waves in the antenna element 112, and by using an adjustment plate 150 having an optimal thickness or relative dielectric constant according to the thickness t of the window glass 11, the operating frequency band of the antenna element 112 can be adjusted to the desired frequency band.

[0092] For example, by preparing multiple types of adjustment plates 150 that can be attached and detached to the holder 130 and have different thicknesses and dielectric constants, and selecting an adjustment plate 150 with the optimal thickness or dielectric constant according to the thickness t of the window glass 11 and attaching it to the holder 130, the operating frequency band of the antenna element 112 can be adjusted to the desired frequency band.

[0093] The operating frequency band of the antenna element 112 is synonymous with the operating frequency band of the patch antenna configured by the antenna element 112 and the ground layer 122 , and the operating frequency band of the antenna device 100 .

[0094] 6B is a diagram showing an example of a simulation result (part 3) of the gain frequency characteristics of antenna device 100 including adjustment plate 150. In the simulation, the thickness t of window glass 11 was set to 3 mm, and gap G was set to 6 mm.

[0095] 6B shows the frequency characteristics of the gain of antenna device 100 that includes an adjustment plate (dashed line) and the frequency characteristics of the gain of antenna device 100 that does not include adjustment plate 150 (solid line). Note that the frequency characteristics of the gain shown by the solid line are the same as the frequency characteristics of the gain shown by the solid line in FIG. 5B.

[0096] In the gain frequency characteristic with adjustment plate 150 shown by the dashed line, a frequency band in which the gain is 6 dBi or more was obtained from 3.2 GHz to 4.4 GHz. The frequency band from 3.2 GHz to 4.4 GHz is shifted to a lower frequency side than the frequency band from 3.45 GHz to 4.5 GHz in which the gain is 6 dBi or more in the gain frequency characteristic without adjustment plate 150 shown by the solid line. The frequency band from 3.2 GHz to 4.4 GHz shown by the dashed line in Figure 6B is closer to the frequency band from 3.0 GHz to 4.1 GHz shown by the solid line in Figure 4B than the frequency band from 3.45 GHz to 4.5 GHz shown by the solid line in Figure 6B.

[0097] In this way, it was confirmed that even if the thickness t of the window glass 11 changes from the thickness t optimized in the antenna device 100, by using the adjustment plate 150, an operating frequency band of the antenna element 112 similar to the operating frequency band of the antenna element 112 at the optimized thickness t can be obtained.

[0098] The effective relative dielectric constant, which is determined by the thickness of window glass 11, adjusting plate 150 provided in gap G, and gap G where air is present, varies depending on the thickness or relative dielectric constant of adjusting plate 150. Therefore, the thickness of adjusting plate 150 in the direction connecting antenna 110 and power feeding portion 120 may be set depending on the distance between antenna 110 and power feeding portion 120. In addition, the relative dielectric constant of adjusting plate 150 may be set depending on the distance between antenna 110 and power feeding portion 120.

[0099] 6B shows that the use of the adjustment plate 150 enabled a frequency band of 3.45 GHz to 4.5 GHz (without the adjustment plate 150) to be shifted to a frequency band of 3.2 GHz to 4.4 GHz. In this way, the use of the adjustment plate 150 enabled a frequency band shift. Therefore, for example, when the radio waves transmitted and received by the base station BS are in the 3.7 GHz band as described above, if the antenna device 100 is to be attached to a windowpane 11 having a thickness t that differs from the thickness t of the windowpane 11 for which the antenna element 112 is designed to operate in the 3.7 GHz band, the following procedure can be performed. That is, by selecting an adjustment plate 150 having a thickness or relative dielectric constant that corresponds to the thickness t of the windowpane 11 to which the antenna device 100 is to be attached, the operating frequency band of the antenna element 112 can be adjusted to the desired frequency band, 3.7 GHz.

[0100] 7A is a diagram illustrating an example of the configuration of an antenna device 100A according to a first modification of the embodiment, which corresponds to the configuration of the −X-direction half of the antenna device 100 illustrated in FIG.

[0101] Antenna device 100A differs from antenna device 100 shown in Fig. 3A in that antenna device 100A is configured so that the outer edge of substrate 111 of antenna 110 fits inside opening 133 of holder 130, which has a rectangular ring shape in a plan view. In other words, in Fig. 7A , holder 130 is a wall member provided on the outside of the four sides of the outer edge of substrate 111. Because substrate 111 fits inside holder 130, which has a rectangular ring shape in a plan view, holder 130 is directly attached to main surface 11A on the indoor side of window glass 11.

[0102] In this way, the holder 130 may be configured to be directly attached to the indoor main surface 11A of the window glass 11. Also, an adjustment plate 150 (see FIG. 6A ) may be provided between the antenna 110 and the power supply unit 120 of the antenna device 100A. The portion of the holder 130 that comes into contact with the window glass 11 may be smaller than the holder shown in FIG. 7A . For example, the holder 130 may be configured to have legs that protrude in the −Z direction at the four corners. Various configurations are possible regarding the number of such legs and their arrangement in a plan view. Also, the holder 130 may be configured so that the substrate 111 fits between adjacent legs.

[0103] <Second Modification> FIG. 7B is a diagram illustrating an example of the configuration of an antenna device 100B according to a second modification of the embodiment.

[0104] The antenna device 100B differs from the antenna device 100 of the embodiment in that it includes a holder 130B instead of the holder 130 shown in Figures 2A to 3A. Here, the differences between the antenna device 100B and the antenna device 100 will be described.

[0105] The holder 130B has a holder main body 131B and two pedestals 132B. The holder main body 131B is, for example, a rectangular ring-shaped (frame-shaped) member in a plan view and has claws 131B1. The claws 131B1 are provided on the inner surfaces of the wall portions on the +X direction side and the −X direction side of the holder main body 131B. In FIG. 7B, the position and general shape of the claws 131B1 provided on the inner surface of the wall portion on the +X direction side are indicated by dashed lines. The +X direction and −X direction side walls of the holder main body 131B have notches on the ±Y direction sides of the claws 131B1.

[0106] The base 132B is provided at a position on the +X and -X sides of the substrate 111 of the antenna 110 where it does not overlap with the antenna element 112 and is positioned inside the +X and -X wall portions of the holder main body 131B. As an example, the surface on the -Z side of the base 132B is attached to the substrate 111. The base 132B is a rectangular parallelepiped member extending in the Y direction and has an engagement portion 132B1 with which the claw portion 131B1 engages. The engagement portion 132B1 is a recess that is recessed in the +Z direction in the center of the Y direction on the surface on the -Z side of the base 132B. As an example, the claw portion 131B1 and the engagement portion 132B1 are configured to engage with each other like a snap fit.

[0107] When attaching the holder main body 131B to the two pedestals 132B, the claw portions 131B1 and the engaging portions 132B1 are engaged with each other, thereby allowing the holder 130B to be attached to the antenna 110. The pedestals 132B may also be attached to the main surface 11A of the window glass 11 on the indoor side.

[0108] <Third Modification> FIG. 7C is a diagram illustrating an example of the configuration of an antenna device 100C according to a third modification of the embodiment.

[0109] The antenna device 100C differs from the antenna device 100 of the embodiment in that it includes a holder 130C instead of the holder 130 shown in Figures 2A to 3A. Here, the differences between the antenna device 100C and the antenna device 100 will be described.

[0110] The holder 130C includes a holder body 131C, two pedestals 132C, and four screws 133C. The holder body 131C is, for example, a rectangular ring-shaped (frame-shaped) member in a plan view. The shapes of the holder body 131C and the pedestals 132C are similar to those of the holder body 131B and the pedestals 132B of the second modified example.

[0111] The base 132C is provided at a position where it does not overlap with the antenna element 112 on the +X direction side and the −X direction side of the substrate 111 of the antenna 110, and is located inside the wall portions on the +X direction side and the −X direction side of the holder main body 131C. As an example, the surface on the −Z direction side of the base 132C is attached to the substrate 111.

[0112] When attaching the holder main body 131C to the two pedestals 132C, the holder main body 131C is placed over the two pedestals 132C, and screws 133C are passed through the outer surface of the holder main body 131C and fastened to the pedestals 132C, thereby attaching the holder 130C to the antenna 110. The pedestals 132C may also be attached to the indoor main surface 11A of the window glass 11.

[0113] <Fourth Modification> FIG. 7D is a diagram illustrating an example of the configuration of an antenna device 100D according to a fourth modification of the embodiment.

[0114] The antenna device 100D differs from the antenna device 100 of the embodiment in that it includes a holder 130D instead of the holder 130 shown in Figures 2A to 3A. Here, the differences between the antenna device 100D and the antenna device 100 will be described.

[0115] The holder 130D has a holder main body 131D and two pedestals 132D. The holder main body 131D is, for example, a rectangular annular (frame-shaped) member in a plan view and has an engaging portion 131D1. The engaging portion 131D1 on the +X direction side protrudes in the -Z direction from the end of the holder main body 131D on the +X direction side and bends in the -X direction. The engaging portion 131D1 on the -X direction side protrudes in the -Z direction from the end of the holder main body 131D on the -X direction side and bends in the +X direction. The two engaging portions 131D1 are provided across the entire Y direction of the holder main body 131D. The engaging portions 131D1 on the +X direction side and the -X direction side engage with grooves 132D1 on the +X direction side and the -X direction side of the pedestal 132D, respectively, and are slidable in the Y direction along the grooves 132D1.

[0116] The base 132D is provided at a position on the +X direction side and the -X direction side of the substrate 111 of the antenna 110 so as not to overlap with the antenna element 112, and so as to be positioned inside the +X direction side and the -X direction side wall of the holder main body 131D. As an example, the surface of the -Z direction side of the base 132D is attached to the substrate 111. The base 132D is a rectangular parallelepiped member extending in the Y direction and has a groove 132D1 with which the engaging portion 131D1 engages. The +X direction side base 132D has a groove 132D1 recessed toward the -X direction formed on its side surface facing the +X direction. The -X direction side base 132D has a groove 132D1 recessed toward the +X direction formed on its side surface facing the -X direction. The groove 132D1 is provided over the entire Y direction of the base 132D.

[0117] When attaching the holder main body 131D to the two pedestals 132D, the engaging portions 131D1 and the grooves 132D1 can be engaged to attach the holder 130D to the antenna 110. As an example, the holder main body 131D may be configured to lock onto the pedestals 132D at a position where the holder main body 131D is slid relative to the pedestals 132D. The holder main body 131D and the pedestals 132D may be fixed with an adhesive or the like, or may be fastened with screws or the like.

[0118] The base 132D may be attached to the indoor main surface 11A of the window glass 11. Alternatively, the holder main body 131D may have a groove, and the two bases 132D may have engaging portions. Alternatively, the groove 132D1 may not be formed at the lower end on the -Y direction side, and the holder main body 131D may be engaged and slid from the +Y direction side to be locked.

[0119] <Fifth Modification> Fig. 7E is a diagram showing an example of the configuration of an antenna device 100E according to a fifth modification of the embodiment, and Fig. 7F is a cross-sectional view showing an example of the configuration of a part of a holder 130E of the antenna device 100E.

[0120] The antenna device 100E differs from the antenna device 100 of the embodiment in that it includes a holder 130E instead of the holder 130 shown in Figures 2A to 3A. Here, the differences between the antenna device 100E and the antenna device 100 will be described.

[0121] The holder 130E has a holder main body 131E and two pedestals 132E. The holder main body 131E is, for example, a rectangular ring-shaped (frame-shaped) member in a plan view, and has through-holes 131E1 at the ends of the +X direction side and the -X direction side of a wall portion extending in the X direction on the +Y direction side and the -Y direction side. For example, a total of four through-holes 131E1 are provided.

[0122] The base 132E is provided at a position where it does not overlap with the antenna element 112 on the +X direction side and the −X direction side of the substrate 111 of the antenna 110, and is located inside the wall portions on the +X direction side and the −X direction side of the holder main body 131E. As an example, the surface on the −Z direction side of the base 132E is attached to the substrate 111.

[0123] The bases 132E are rectangular parallelepiped members extending in the Y direction. As shown in FIG. 7F , each base 132E has two movable protrusions 132E1 provided at positions corresponding to the two through-holes 131E1, three springs 132E2, two movable plates 132E3, and a through-hole 132E4 (see FIG. 7 ). The through-hole 132E4 connects the portions housing the two movable protrusions 132E1 in the Y direction.

[0124] The movable convex portion 132E1 is, for example, a spherical member. The +Y direction side movable convex portion 132E1 has a +Y direction half that protrudes outward from the +Y direction end of the through hole 132E4. The -Y direction side movable convex portion 132E1 has a -Y direction half that protrudes outward from the -Y direction end of the through hole 132E4. The movable convex portion 132E1 is movable so as to retract into the through hole 132E4.

[0125] The three springs 132E2 are arranged in series inside the through-hole 132E4 of the base 132E between the movable convex portion 132E1 on the +Y direction side and the movable convex portion 132E1 on the -Y direction side. The movable plate 132E3 on the +Y direction side is sandwiched between the central spring 132E2 and the spring 132E2 on the +Y direction side, and the movable plate 132E3 on the -Y direction side is sandwiched between the central spring 132E2 and the spring 132E2 on the -Y direction side. Of the three springs 132E2, the central spring 132E2 has the largest spring constant, and the spring constants of the springs 132E2 on the +Y direction side and the -Y direction side are smaller than the spring constant of the central spring 132E2.

[0126] The base 132E also has an opening at the center of the through-hole 132E4 in the Y direction, which exposes the +X direction ends of the two movable plates 132E3 to the outside. The movable plates 132E3 are movable in the Y direction at the opening of the opening.

[0127] With the movable convex portion 132E1 pressed into the through-hole 132E4, the holder main body 131E is placed over the two pedestals 132E and the positions of the movable convex portion 132E1 and the through-hole 131E1 are aligned, whereby the movable convex portion 132E1 protrudes into the through-hole 131E1, thereby fixing the holder main body 131E to the pedestal 132E. In this manner, the holder 130C can be attached to the antenna 110.

[0128] Furthermore, when removing the holder main body 131E from the pedestal 132E, by pinching the two movable plates 132E3 with your hands and moving them in a direction that brings them closer together, the movable convex portion 132E1 on the +Y direction side and the movable convex portion 132E1 on the −Y direction side are housed inside the through-hole 132E4. In this state, by pulling the holder main body 131E out of the pedestal 132E, the holder main body 131E can be removed from the pedestal 132E.

[0129] The holder body 131E can be repeatedly attached to and detached from the base 132E. The base 132E may be attached to the main surface 11A of the window glass 11 on the indoor side.

[0130] 7G is a diagram illustrating an example of the configuration of an antenna device 100G according to a sixth modification of the embodiment. The antenna device 100G differs from the antenna device 100 illustrated in FIG. 3A in that the holder portions 131 and 132 are configured by dividing the holder 130 into two in the X direction.

[0131] For example, holder portion 131 is located on the −X direction side, and holder portion 132 is located on the +X direction side. Fig. 7G shows the entire holder portion 131 and only a portion of holder portion 132 on the −X direction side. When holder portions 131 and 132 are combined, they form a rectangular ring (frame-like) shape in a plan view, with an opening in the center.

[0132] The position at which the holder 130 of the antenna device 100G is divided into two holder parts 131 and 132 in the X direction may be the center in the X direction, or may be a position shifted toward the +X direction or the −X direction from the center in the X direction.

[0133] 7H is a diagram illustrating an example of the configuration of an antenna device 100H according to a seventh modification of the embodiment. The antenna device 100H differs from the antenna device 100 illustrated in FIG. 3A in that the holder portions 131 and 132 are configured by dividing the holder 130 into two in the Y direction.

[0134] For example, holder portion 131 is located on the -Y direction side, and holder portion 132 is located on the +Y direction side. Fig. 7H shows only the half portion on the -X direction side of the entire holder portions 131 and 132. When holder portions 131 and 132 are combined, they form a rectangular ring (frame-like) shape in a plan view, with an opening in the center.

[0135] The position at which the holder 130 of the antenna device 100H is divided into two holder parts 131 and 132 in the Y direction may be the center in the Y direction, or may be a position shifted toward the +Y direction or the -Y direction from the center in the Y direction.

[0136] <Effects> The antenna device 100 includes an antenna 110 that is affixed to the indoor main surface 11A of the window glass 11, the antenna 110 having a first substrate 111 and an antenna element 112 provided on the first substrate 111, a holder 130 (holding portion) that is attached to the indoor main surface 11A of the window glass 11 or the antenna 110, and a power supply unit 120 that is held by the holder 130 (holding portion), the power supply unit 120 having a second substrate 121, a ground layer 122 that is provided on a first surface of the second substrate 121 that faces the antenna 110, a slot antenna 122A that is formed on the ground layer 122 and that is coupled to the antenna element 112, and a power supply line 123 that is provided on the second surface of the second substrate 121 and that supplies power to the slot antenna 122A. Since the antenna 110 is attached to the indoor main surface 11A of the window glass 11, the protrusion of the antenna device 100 from the main surface 11A can be reduced.

[0137] Therefore, it is possible to provide the antenna device 100 that can be made low-profile when attached to the window glass 11 .

[0138] Furthermore, the holder 130 (holding portion) is attached to the indoor main surface 11A of the window glass 11, and may be located outside the outer edge of the antenna 110 in a plan view. The holder 130 can be located outside the outer edge of the antenna 110 and directly attached to the main surface 11A. This makes it possible to provide an antenna device 100 in which the holder 130 can be stably attached to the main surface 11A and which can be made low-profile.

[0139] Furthermore, the first substrate 111 of the antenna 110 has a rectangular shape in a plan view, and the holder 130 (holding portion) may be a wall member provided on two opposing sides, three of the four sides, or the outside of the four sides of the outer edge of the first substrate 111 in a plan view. With the holder 130 configured as a wall member provided on two opposing sides, three of the four sides, or the outside of the four sides of the outer edge of the first substrate 111, it is possible to provide an antenna device 100 in which the holder 130 can be stably attached to the main surface 11A and which can be made low-profile.

[0140] Furthermore, the holder 130 (holding portion) is attached to the first substrate 111 of the antenna 110, and may be located outside the antenna element 112 in a plan view. By attaching the holder 130 to the first substrate 111 at a portion outside the antenna element 112, the holder 130 can be attached directly to the first substrate 111. It is possible to provide an antenna device 100 in which the holder 130 can be stably attached to the first substrate 111 and which can be made low-profile.

[0141] Furthermore, the first substrate 111 of the antenna 110 may be rectangular in plan view, and the holder 130 (holding portion) may be a wall member attached to the first substrate 111 along two opposing sides, three of the four sides, or all four sides of the outer edge of the first substrate 111. With the holder 130 configured as a wall member attached to the first substrate 111 along two opposing sides, three of the four sides, or all four sides of the outer edge of the first substrate 111, it is possible to provide an antenna device 100 in which the holder 130 can be stably attached to the first substrate 111 and which can be made low-profile.

[0142] Furthermore, the antenna element 112 may have a rectangular, circular, or polygonal shape in a plan view. A patch antenna configured with an antenna element 112 having a rectangular, circular, or polygonal shape in a plan view and a ground layer 122 can provide an antenna device 100 that can radiate in a direction from the ground layer 122 toward the antenna element 112 and can achieve a low profile.

[0143] The antenna may further include an adjustment plate 150 made of a dielectric material held between the antenna 110 and the power supply unit 120 by the holder 130 (holding unit), the adjustment plate 150 adjusting the electrical length of the radio waves in the antenna element 112. By adjusting the electrical length of the radio waves in the antenna element 112 with the adjustment plate 150, the operating frequency band of the antenna element 112 can be adjusted to a desired frequency band.

[0144] The adjustment plate 150 is detachably held by the holder 130. By using an optimum adjustment plate 150 according to the thickness t of the window glass 11, the operating frequency band of the antenna element 112 can be adjusted to a desired frequency band.

[0145] Furthermore, the thickness of adjustment plate 150 in the direction connecting antenna 110 and power supply unit 120 may be set according to the thickness t of window glass 11. Since the operating frequency band of antenna element 112 changes according to the thickness t of window glass 11, by using adjustment plate 150 having a thickness set according to the thickness t of window glass 11, it is possible to adjust the effective relative dielectric constant and adjust the operating frequency band of antenna element 112 to a desired frequency band.

[0146] The relative dielectric constant of the adjusting plate 150 may be set according to the thickness t of the window glass 11. Since the operating frequency band of the antenna element 112 changes depending on the thickness t of the window glass 11, by setting the relative dielectric constant of the adjusting plate 150, the effective relative dielectric constant can be adjusted, and the operating frequency band of the antenna element 112 can be adjusted to a desired frequency band.

[0147] The wireless communication device 200 includes any one of the antenna devices 100 described above, and a communication device 180 that is connected to the antenna 110 and is arranged separately from the antenna 110 around the window where the window glass 11 is provided, and that performs wireless communication via the antenna 110. Since the antenna 110 is attached to the indoor-side main surface 11A of the window glass 11, it is possible to reduce the protrusion of the antenna device 100 from the main surface 11A.

[0148] Therefore, it is possible to provide a wireless communication device 200 including an antenna device 100 that can be made low-profile when attached to a window glass 11 .

[0149] 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.

[0150] This international application claims priority based on Japanese Patent Application No. 2023-113097, filed on July 10, 2023, the entire contents of which are incorporated herein by reference.

[0151] 1 Building 1W Wall 10 Window 11 Window glass 12 Window frame 100, 100A to 100E, 100G, 100H Antenna device 110 Antenna 111 Substrate (an example of a first substrate) 112 Antenna element 120 Power supply unit 121 Substrate (an example of a second substrate) 122 Ground layer 122A Slot antenna 123 Power supply line 130, 130B to 130E Holder (an example of a holding unit) 140 Transmission cable 150 Adjustment plate 180 Communication device 200 Wireless communication device

Claims

1. An antenna to be attached to the main indoor surface of a windowpane, comprising a first substrate and an antenna element provided on the first substrate, The main surface of the window glass on the indoor side or the holding part attached to the antenna, A power supply unit held by the holding unit, comprising: a second substrate; a ground layer provided on the first surface of the second substrate on the antenna side; a slot antenna formed in the ground layer and coupled to the antenna element; and a power supply line provided on the second surface of the second substrate for supplying power to the slot antenna. Antenna equipment, including

2. The antenna device according to claim 1, wherein the holding portion is attached to the main surface on the indoor side of the window glass and, in a plan view, is located outside the outer edge of the antenna.

3. The first substrate of the antenna is rectangular in plan view. The antenna device according to claim 2, wherein the holding portion is, in a plan view, two opposite sides of the four sides of the outer edge of the first substrate, three sides of the four sides, or a wall member provided on the outside of the four sides.

4. The antenna device according to claim 1, wherein the holding portion is attached to the first substrate of the antenna and is located outside the antenna element in a plan view.

5. The first substrate of the antenna is rectangular in plan view. The antenna device according to claim 4, wherein the holding portion is a wall member attached to the first substrate along two opposite sides of the four sides of the outer edge of the first substrate, three sides of the four sides, or along the four sides.

6. The antenna device according to claim 1, wherein the antenna element is rectangular, circular, or polygonal in plan view.

7. The antenna device according to claim 1, further comprising a dielectric adjustment plate held between the antenna and the power supply unit by the holding unit, the adjustment plate being used to adjust the electrical length of the radio wave in the antenna element.

8. The antenna device according to claim 7, wherein the adjustment plate is detachably held in the holding portion.

9. The antenna device according to claim 7, wherein the thickness of the adjustment plate in the direction connecting the antenna and the power supply unit is set according to the thickness of the window glass.

10. The antenna device according to claim 7, wherein the relative permittivity of the adjustment plate is set according to the thickness of the window glass.

11. An antenna device according to any one of claims 1 to 10, A communication device is connected to the aforementioned antenna and is positioned separately from the antenna around the window where the window glass is installed, and performs wireless communication via the antenna. Wireless communication devices, including those mentioned above.