Antenna device and wireless communication device

Abstract

To provide an antenna device having a good appearance and a wireless communication device.SOLUTION: An antenna device includes a base having a first principal surface on an indoor side and a second principal surface on an outdoor side, a first conductor pattern formed on the first principal surface, a second conductor pattern formed on the second principal surface, and a first concealment pattern formed on the first principal surface at a position overlapping with the second conductor pattern in a planar view. The second conductor pattern and the first concealment pattern have mesh patterns formed in a mesh shape in the planar view, and the mesh pattern of the second conductor pattern and the mesh pattern of the first concealment pattern coincide with each other in the planar view.SELECTED DRAWING: Figure 4D

Description

[Technical field]

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

[0002] 2. Description of the Related Art Conventionally, there has been a patch antenna in which an antenna portion made of mesh metal is formed on one surface of a transparent film substrate, and a ground portion made of mesh metal is formed on the other surface (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Patent Publication No. 2021 / 229994 Summary of the Invention [Problem to be solved by the invention]

[0004] However, since the mesh metal has a metallic luster, the antenna section and the ground section are noticeable when viewed from the opposite side of the transparent film substrate. In particular, since the ground section is larger than the antenna section, it is very noticeable when viewed from the antenna section side. Thus, conventional patch antennas (antenna devices) do not look good because the mesh metal stands out due to its metallic luster.

[0005] It is therefore an object of the present invention to provide an antenna device and a wireless communication device that have a good appearance. [Means for solving the problem]

[0006] An antenna device according to an embodiment of the present disclosure includes a base having a first principal surface on an indoor side and a second principal surface on an outdoor side, a first conductor pattern formed on the first principal surface, a second conductor pattern formed on the second principal surface, and a first concealment pattern formed on the first principal surface at a position overlapping with the second conductor pattern in a planar view, wherein the second conductor pattern and the first concealment pattern have mesh patterns formed in a mesh shape in a planar view, and the mesh pattern of the second conductor pattern and the mesh pattern of the first concealment pattern coincide with each other in a planar view. Effect of the Invention

[0007] It is possible to provide an antenna device and a wireless communication device that have a good appearance. [Brief description of the drawings]

[0008] [Figure 1] 1 is a diagram showing an example of a building 1 in which a wireless communication device 200 including an antenna device 100 of an embodiment is installed, as viewed from the side. [Figure 2A] 1 is a diagram illustrating an example of the configuration of an antenna device 100. FIG. [Figure 2B] 2 is a diagram showing an example of the configuration of a reflector 130 of the antenna device 100. FIG. [Diagram 3] FIG. 2 is a diagram showing an example of a circuit configuration of a communication device 180. [Figure 4A] 2 is a diagram showing an example of the configuration of a spiral antenna 110. FIG. [Figure 4B] 2 is a diagram showing an example of the configuration of a spiral antenna 110. FIG. [Figure 4C] 2 is a diagram showing an example of the configuration of a spiral antenna 110. FIG. [Figure 4D] 2 is a diagram showing an example of the configuration of a concealment pattern 120. FIG. [Diagram 5] 4A to 4C are diagrams illustrating an example of measurement results of the antenna device 100. [Figure 6A] FIG. 13 is a diagram showing an example of the configuration of an antenna 110M1 before a blackening process is performed. [Figure 6B]FIG. 13 is a diagram showing an example of a variation (part 1) of a blackening process. [Figure 6C] FIG. 13 is a diagram showing an example of a variation (part 2) of a blackening process. [Figure 6D] FIG. 13 is a diagram showing an example of a variation (part 2) of a blackening process. [Figure 6E] FIG. 13 is a diagram showing an example of a variation (part 2) of a blackening process. [Figure 6F] FIG. 13 is a diagram showing an example of a variation (part 3) of the blackening process. [Figure 7A] 2 is a diagram showing an example of the configuration of a patch antenna 210. FIG. [Figure 7B] 2 is a diagram showing an example of the configuration of a patch antenna 210. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[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 are denoted by the same reference numerals, and duplicated descriptions may be omitted.

[0010] In the following, the XYZ coordinate system is defined and explained. 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 mutually perpendicular. The XYZ coordinate system is an example of an orthogonal coordinate system. In the following, planar view refers to viewing 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., are allowed to be misaligned to an extent that does not impair the effect of the embodiment.

[0011] In the following, a configuration will be described in which the antenna device is disposed facing the indoor main surface of the window glass 11. In this case, the Z direction is the thickness direction connecting the indoor main surface and the outdoor main surface of the window glass 11. The radiating portion of the antenna device extends along the XY plane. A plan view means a front view of the radiating portion of the antenna device.

[0012] In the following explanation, "radio waves" refers to a type of electromagnetic wave, and generally, electromagnetic waves below 3 THz are called radio waves. In the following, electromagnetic waves below 3 THz emitted from outdoor base stations or relay stations are called "radio waves," and electromagnetic waves in general are called "electromagnetic waves." In the following, "millimeter waves" or "millimeter wave band" includes the quasi-millimeter wave band of 24 GHz to 30 GHz in addition to the frequency band of 30 GHz to 300 GHz.

[0013] <Embodiment> <Overview of the Antenna Device 100 and the 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.

[0014] The wireless communication device 200 of the embodiment can function as a repeater that receives radio waves arriving from a base station or relay station, performs processing such as amplification without converting the frequency, and then radiates the radio waves. The wireless communication device 200 of the embodiment can also function as a repeater that receives radio waves arriving from a base station, performs processing such as frequency conversion and amplification, and then radiates the radio waves.

[0015] The wireless communication device 200 includes an antenna device 100 and a communication device 180. The antenna device 100 includes a transmission cable 150 in addition to an antenna and a reflector. The communication device 180 is connected to the antenna of the antenna device 100 via the transmission cable 150. Details of the antenna device 100 will be described later with reference to Figs. 2A to 3D.

[0016] In the following description, the antenna device 100 is a spiral antenna, for example. However, the antenna device 100 may be a patch antenna, for example, as long as it has conductor layers on both sides of a substrate.

[0017] 1 shows an outdoor base station BS and a smartphone 50 in addition to the building 1 and the wireless communication device 200. The base station BS is an example of an external device located outside the building 1. Although the base station BS is shown in FIG. 1, 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.

[0018] Unless otherwise specified, the following description of the operation and configuration of wireless communication device 200 will focus on the operation of wireless communication device 200 receiving radio waves. Since the operation of wireless communication device 200 transmitting radio waves is the opposite operation of the operation of receiving radio waves, a description of the operation of wireless communication device 200 transmitting radio waves may be omitted.

[0019] The building 1 may be a detached house, a building, an apartment, or a commercial facility such as a shopping mall or a department store, an airport, a factory, an electric power facility, a government building, a station (station building), or a bus stop building. The window 10 is used in these buildings 1. The window 10 includes a window glass 11 and a window frame (the window frame on the building 1 side). The wireless communication device 200 is provided, for example, inside the building 1, and has a function as a repeater that relays radio waves arriving from the outdoors to the indoor side and relays radio waves from the indoor side to the outdoors. Note that, here, as an example, a form in which the wireless communication device 200 is provided inside the building 1 will be described.

[0020] In Fig. 1, the XYZ coordinate system is defined, as an example, with reference to the indoor principal surface of the window glass 11. The window glass 11 may be either single-pane glass or double-glazed glass. The indoor principal surface of the window glass 11 that serves as the reference for the XYZ coordinate system is the principal surface on the +Z direction side, and the outdoor principal surface of the window glass 11 is the principal surface on the -Z direction side. The +Z direction side principal surface of the window glass 11 and the outdoor principal 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.

[0021] The radio waves relayed by the wireless communication device 200 including the antenna device 100 are preferably radio waves in a frequency band of 600 MHz to 40 GHz including the Sub-6 frequency band and millimeter wave band of the fifth generation mobile communication system (5G) etc. The wireless communication device 200 relays radio waves arriving from an outdoor base station BS etc. indoors. The wireless communication device 200 may also have a function of receiving radio waves arriving from a base station BS etc., converting the radio waves into radio waves of a communication standard different from that of the radio waves arriving from the base station BS etc., and relaying the radio waves indoors.

[0022] Moreover, the radio waves relayed by the wireless communication device 200 may be Long Term Evolution (LTE), LTE-Advanced (LTE-A), Ultra Mobile Broadband (UMB), or Citizens Broadband Radio Service (CBRS). Moreover, the radio waves relayed by the wireless communication device 200 may be IEEE802.11 (Wi-Fi (registered trademark)), IEEE802.16 (WiMAX (registered trademark)), IEEE802.20, Ultra-Wideband (UWB), Bluetooth (registered trademark), or Low Power Wide Area (LPWA), etc.

[0023] 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 that the frequency of the radio waves is relatively high. The boundary frequency between the frequency of the radio waves that penetrates the wall 1W of the building 1 and the frequency of the 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, is about 600 MHz to 3 GHz.

[0024] 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 weak and the radio wave strength is not practically sufficient for communication using a terminal such as a smartphone 50 or a PC (Personal Computer) inside (indoors) the wall 1W of the building 1.

[0025] Radio waves transmitted from the base station BS do not penetrate the wall 1W of the building 1, and therefore penetrate only the window glass 11 of the window 10 to enter the building. Radio waves transmitted from the base station BS have high linearity, and therefore reach only the line of sight (LOS) area of ​​the window 10, which tends to create blind zones 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 penetrating 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 on the way. The line of sight area of ​​the window 10 is an area where such direct waves or reflected waves penetrate the window 10 to enter the building 1.

[0026] Here, a case will be described in which radio waves transmitted from a base station BS do not penetrate the wall 1W of a building 1, but penetrate only the window glass 11 to enter a building. The lower limit of the frequency of such radio waves is, for example, about 600 MHz to 3 GHz.

[0027] The antenna device 100 and the wireless communication device 200 are preferably used when 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 to enter the building. However, the antenna device 100 and the wireless communication device 200 may also be used when radio waves transmitted from the base station BS penetrate the wall 1W of the building 1. This is because, even in such a case, the loss of radio waves penetrating the window glass 11 is smaller than the loss of radio waves penetrating the wall 1W, and radio waves of higher intensity can be received.

[0028] 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 transmission cable 150 connects the spiral antenna of the antenna device 100 to the communication device 180. When the antenna device 100 includes multiple spiral antennas, one transmission cable 150 may be connected to each spiral antenna, or one transmission cable 150 may be connected to multiple spiral antennas.

[0029] 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 50 or a PC indoors.

[0030] <Configuration of Windows 10> In the following, an example will be described in which the window 10 is a fixed window, but the window 10 may be a sliding window that can be opened and closed freely, or a casement window. Also, the window glass 11 held by the window frame may be either one piece or multiple pieces.

[0031] The window glass 11 has a main surface on the indoor side (+Z direction side) and a main surface on the outdoor side (-Z direction side). 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 be a surface material made of resin such as polycarbonate or acrylic.

[0032] <Specific Configuration of Antenna Device 100> A specific configuration of the antenna device 100 will be described with reference to Fig. 1 as well as Fig. 2A and Fig. 2B. Fig. 2A is a diagram showing an example of the configuration of the antenna device 100. Fig. 2B is a diagram showing an example of the configuration of a reflector 130 of the antenna device 100. Fig. 2A also shows a window glass 11. The window glass 11 has a main surface 11A on the indoor side and a main surface 11B on the outdoor side.

[0033] Although the antenna device 100 may include a plurality of spiral antennas 110, a configuration including one spiral antenna 110 will be described as an example here. For example, when performing Multiple-Input and Multiple-Output (MIMO) communication, the antenna device 100 may include a plurality of spiral antennas 110.

[0034] The antenna device 100 includes a spiral antenna 110, a concealment pattern 120, a reflector 130, a matching layer 140, and a transmission cable 150. The spiral antenna 110 is an example of an antenna of the antenna device 100. When the antenna device 100 includes a plurality of spiral antennas 110, the antenna device 100 also includes a plurality of reflectors 130, and the number of the plurality of spiral antennas 110 is equal to the number of the plurality of reflectors 130. Also, one reflector 130 is provided corresponding to each spiral antenna 110 in a front view.

[0035] As an example, the antenna device 100 is attached to the indoor main surface 11A of the window glass 11 via a holder (not shown). Such a holder is, as an example, made of resin transparent to visible light, and holds the substrate of the spiral antenna 110 and the reflector 130 in a state where it is fixed to the main surface 11A of the window glass 11 with double-sided tape or the like.

[0036] "Transparent" to visible light means that the visual transmittance is at least 40%, 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 holder may be made of transparent glass. The transparency of the holder can suppress obstruction of the view through the window glass 11.

[0037] <Spiral Antenna 110> The spiral antenna 110 has radiating parts and the like formed on both sides of a substrate. The spiral antenna 110 is transparent to visible light, for example. A matching layer 140 is provided between the spiral antenna 110 and the main surface 11A of the window glass 11. As an example, the spiral antenna 110 is bonded to the window glass 11 by a fixing member such as a holder so as to be parallel to the main surface 11A of the window glass 11 and with a gap of about 10 mm between the spiral antenna 110 and the main surface 11A. Here, a form in which the spiral antenna 110 is arranged so as to be parallel to the main surface 11A of the window glass 11 will be described, but the spiral antenna 110 may not be parallel to the main surface 11A of the window glass 11. The detailed configurations of the spiral antenna 110 and the concealment pattern 120 will be described later with reference to Figs. 4A to 4D.

[0038] <Reflector 130> The reflector 130 is provided on the +Z direction side of the spiral antenna 110, and is fixed to the substrate of the spiral antenna 110, for example. The reflector 130 has a rectangular shape in a plan view, for example. The reflector 130 is transparent to visible light. The reflector 130 may be fixed to a portion of the spiral antenna 110 other than the substrate.

[0039] The reflector 130 has a substrate 131 and a reflective conductor 132. The substrate 131 is 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.

[0040] As an example, a resin substrate (resin film) may be used as the substrate 131. Examples of resin materials that are transparent to visible light include acrylic resins such as polymethyl methacrylate, cycloolefin resins, polycarbonate resins, polyethylene terephthalate (PET), and the like. Also, a glass plate may be used as the substrate 131. Examples of glass plates that are transparent to visible light include soda-lime glass, alkali-free glass, Pyrex (registered trademark) glass, and quartz glass. Note that, here, as an example, a form in which the substrate 131 is a resin substrate will be described.

[0041] As an example, the reflective conductor 132 is provided on the principal surface of the substrate 131 on the -Z direction side. However, the reflective conductor 132 may be provided on the principal surface of the substrate 131 on the +Z direction side, or may be sandwiched between the substrate 131 and a substrate (not shown) and not exposed. Alternatively, the reflective conductor 132 may be provided on an inner layer of any of a plurality of substrates. The reflector 130 has a principal surface on the +Z direction side and a principal surface on the -Z direction side.

[0042] The reflective conductor 132 may be a conductive film that is transparent to visible light and is formed without gaps over the entire main surface in the -Z direction of the substrate 131. The meaning of "transparent" to visible light is the same as that of the substrate 131.

[0043] Since a metallic luster such as a mesh-like thin metal film would be conspicuous, the reflective conductor 132 is composed of a transparent conductive film formed without gaps over its entire surface, rather than a mesh-like thin metal film. The transparent conductive film used as the reflective conductor 132 may be formed of transparent conductive films such as zinc oxide (ZnO), tin oxide (SnO2), tin-doped indium oxide (ITO), indium oxide-tin oxide (IZO), etc., metal nitrides such as titanium nitride (TiN) and chromium nitride (CrN), or low-e films for low-e glass.

[0044] As described above, in the configuration in which the substrate 131 is transparent to visible light and the reflective conductor 132 is a transparent conductive film, the reflector 130 only needs to have a luminous transmittance of 50% or more.

[0045] <Matching layer 140> The matching layer 140 is transparent to visible light, and is provided between the main surface 11A of the window glass 11 and the spiral antenna 110. The meaning of "transparent" to visible light is the same as that of the substrate 131 and the reflective conductor 132 of the reflector 130, and 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.

[0046] The matching layer 140 is larger than the spiral antenna 110 in a plan view, and is disposed so as to include the outer edge of the spiral antenna 110 in a plan view. The holder that holds the matching layer 140 between the window glass 11 and the spiral antenna 110 may be, for example, a holder that attaches the antenna device 100 to the window glass 11. In addition, the holder that holds the matching layer 140 between the window glass 11 and the spiral antenna 110 may be, for example, a holder fixed to the -Z direction side of a substrate or the like of the spiral antenna 110, separate from the holder that attaches the antenna device 100 to the window glass 11, or may be a holder fixed to the main surface 11A of the window glass 11.

[0047] When radio waves pass through the window glass 11, the radio waves are attenuated. In order to suppress the attenuation (loss) of the radio waves, a matching layer 140 may be provided. When the spiral antenna 110 transmits and receives radio waves, the matching layer 140 adjusts the electrical length of the radio waves passing through the window glass 11 to match the impedance, thereby reducing the loss. Such a matching layer 140 can be made of a material transparent to visible light, such as polycarbonate, acrylic, COP (cycloolefin polymer), PET (polyethylene terephthalate), polystyrene, or glass, for example. Note that if the attenuation of radio waves as described above does not become a problem even without the matching layer 140, the antenna device 100 does not need to include the matching layer 140.

[0048] <Transmission cable 150> The transmission cable 150 has one end connected to the feed point and ground potential point of the spiral antenna 110, and the other end connected to the communication device 180 in the device main body 101. The transmission cable 150 is, for example, a coaxial cable. One end of the transmission cable 150 is connected to the feed point and ground potential point of the spiral antenna 110 via a coaxial connector 155.

[0049] The transmission cable 150 transmits signals between the spiral antenna 110 and the communication device 180. In Fig. 1 and Fig. 2A, the transmission cable 150 is connected to the underside of the spiral antenna 110, but it may be connected to the side or the top of the spiral antenna 110.

[0050] <Circuit configuration of communication device 180> Fig. 3 is a diagram showing an example of a circuit configuration of communication device 180. Communication device 180 is provided inside device body 101 (see Fig. 1). Fig. 3 shows the configuration of a portion corresponding to one spiral antenna 110 in the overall configuration of communication device 180. Spiral antenna 110 is connected to communication device 180 via transmission cable 150.

[0051] If the distance between the spiral antenna 110 and the communication device 180 is long, the transmission loss of radio waves increases in the transmission cable 150 between the spiral antenna 110 and the communication device 180. Therefore, in order to reduce the transmission loss of radio waves, it is preferable to attach the communication device 180 to, for example, the window glass 11 or a wall 1W or ceiling around the window 10. Also, for example, the communication device 180 may be disposed on the frame of a bay window.

[0052] As an example, the communication device 180 includes an array antenna 180A, a wireless module 181, a switch 182, a low noise amplifier (LNA) 183, a mixer 184, an analog to digital converter (ADC) 185, a digital to analog converter (DAC) 186, a mixer 187, and a power amplifier (PA) 188.

[0053] When the antenna device 100 includes a plurality of spiral antennas 110, the switch 182, the LNA 183, the mixer 184, the ADC 185, the DAC 186, the mixer 187, and the PA 188 in the communication device 180 are provided one for each spiral antenna 110. The communication device 180 includes the same number of components from the switch 182 to the PA 188 as the number of spiral antennas 110. As for the wireless module 181, as an example, it is common to the plurality of spiral antennas 110, and there is only one wireless module 181.

[0054] As an example, the array antenna 180A is provided inside the housing of the communication device 180, or outside the communication device 180 and inside the device body 101 (see FIG. 1). The array antenna 180A is an array antenna used when the communication device 180 transmits and receives radio waves inside the building 1. The array antenna 180A may be provided outside the housing of the communication device 180, or may be provided outside the device body 101 (see FIG. 1). The communication device 180 may be configured to include a single antenna instead of multiple antennas arranged in an array like the array antenna 180A.

[0055] The wireless module 181 is configured by an MCU (Micro Controller Unit) as an example, and includes a control unit 181A and a relay unit 181B that performs relay processing. The control unit 181A and the relay unit 181B are functional blocks representing functions executed by the MCU.

[0056] When the spiral antenna 110 receives radio waves, the control unit 181A switches the three-terminal switch 182 to connect the spiral antenna 110 to the LNA 183. When the spiral antenna 110 transmits radio waves, the control unit 181A switches the three-terminal switch 182 to connect the spiral antenna 110 to the PA 188.

[0057] The relay unit 181B includes a communication unit of Wi-Fi (registered trademark) as an example, is connected to the array antenna 180A, and transmits radio waves based on a digital signal input from the ADC 185 from the array antenna 180A to the inside of the building 1. The relay unit 181B transmits radio waves to the inside of the building 1 via the array antenna 180A, whereby the radio waves received by the spiral antenna 110 from the base station BS are relayed, and the radio waves are radiated to the inside of the building 1 in which the communication device 180 is located. As a result, the radio waves are radiated over a wide range inside the building 1, making it easier for a terminal such as a smartphone 50 located indoors to receive the radio waves. Note that the communication unit that radiates the radio waves that the relay unit 181B relays to the indoor side is not limited to Wi-Fi, and may be Bluetooth (registered trademark) or the like.

[0058] Furthermore, relay unit 181B performs relay processing on radio waves transmitted from an indoor terminal such as smartphone 50 and received by array antenna 180A, and outputs the radio waves to DAC 186. This allows array antenna 180A to receive radio waves from a wide range inside building 1, making it easier for indoor terminals such as smartphone 50 to transmit radio waves.

[0059] The LNA 183 is provided between the switch 182 and the mixer 184, and amplifies the radio waves received by the spiral antenna 110 and outputs the amplified waves while preventing deterioration of the signal-to-noise ratio.

[0060] The mixer 184 mixes the radio wave output from the LNA 183 with a local signal (LO) to demodulate it, and outputs an IF (Intermediate Frequency) signal. By converting it into an IF signal, the ADC 185 can easily perform digital conversion.

[0061] The ADC 185 digitally converts the IF signal output from the mixer 184 and outputs the digital signal to the wireless module 181 .

[0062] When the relay unit 181B of the wireless module 181 performs relay processing on the signal received by the array antenna 180A and transmits the signal from the spiral antenna 110, the DAC 186 converts the signal output by the relay unit 181B into an analog signal and outputs the IF signal to the mixer 187.

[0063] The mixer 187 mixes the IF signal with a local signal (LO) to modulate it, and outputs the modulated signal to the PA 188 .

[0064] The PA 188 amplifies the signal output from the mixer 187 and outputs it to the transmission cable 150 via the switch 182. As a result, a radio wave is radiated from the spiral antenna 110.

[0065] When the radio waves handled by communication device 180 are Sub-6, communication device 180 may not include mixers 184 and 187. In this case, the signal input to ADC 185 and the signal output from DAC 186 are not IF signals but signals in the Sub-6 frequency band.

[0066] Further, although a configuration in which communication device 180 performs frequency conversion and amplification has been described here, communication device 180 may be configured to perform processing such as amplification without converting the frequency.

[0067] The communication device 180 may include an antenna that receives radio waves of a frequency that penetrates the wall 1W of the building 1. Such an antenna may be provided inside the device body 101 outside the communication device 180, or may be provided inside the communication device 180. In this case, the relay unit 181B may relay the radio waves received by the spiral antenna 110 and also relay an antenna that receives radio waves of a frequency that penetrates the wall 1W. The communication device 180 can relay radio waves of a frequency that penetrates the wall 1W of the building 1 in addition to radio waves of a frequency that do not penetrate the wall 1W of the building 1, so that communication over a wider frequency band is possible.

[0068] <Detailed configuration of the spiral antenna 110 and the concealment pattern 120> 4A, 4B, and 4C are diagrams showing an example of the configuration of the spiral antenna 110. FIG.

[0069] The spiral antenna 110 has a substrate 110A, a first radiating portion 111, a second radiating portion 112, and a power feed line 113. The substrate 110A is an example of a base. The first radiating portion 111 is an example of a first radiating portion. The power feed line 113 is an example of a first conductor pattern. The second radiating portion 112 is an example of a second conductor pattern.

[0070] The concealment pattern 120 is formed on the surface of the spiral antenna 110 on the indoor side (+Z direction side), but in FIGS. 4A to 4C, the concealment pattern 120 is omitted and the configuration of only the spiral antenna 110 is shown.

[0071] <Substrate 110A> The substrate 110A is a plate-like member having a rectangular shape in a plan view. The substrate 110A is fixed to a holder that attaches the antenna device 100 to the window glass 11, for example.

[0072] The substrate 110A has a main surface 110A1 on the indoor side and a main surface 110A2 on the outdoor side. The main surface 110A1 is the surface on the +Z direction side of the substrate 110A (the side opposite to the window glass 11). The main surface 110A2 is the surface located on the opposite side of the main surface 110A1 (the side facing the window glass 11).

[0073] As an example, the antenna device 100 and the wireless communication device 200 are located indoors, and therefore the substrate 110A is located indoors. The main surface 110A1 is located closer to the indoor side than the main surface 110A2, and the main surface 110A2 is located closer to the outdoor side than the main surface 110A1. The main surface 110A1 on the indoor side means that it is located closer to the indoor side than the main surface 110A2, and the main surface 110A2 on the outdoor side means that it is located closer to the outdoor side than the main surface 110A1.

[0074] The principal surface 110A1 and the principal surface 110A2 are parallel to each other. As an example, the principal surface 110A1 is an example of a first principal surface of the base, and the principal surface 110A2 is an example of a second principal surface of the base. In the following description, the principal surface 110A1 is assumed to be the principal surface of the spiral antenna 110.

[0075] The first radiating portion 111 and the power feed line 113 are provided on the main surface 110A1, and the second radiating portion 112 is provided on the main surface 110A2. Conversely, the second radiating portion 112 may be provided on the main surface 110A1, and the first radiating portion 111 and the power feed line 113 may be provided on the main surface 110A2. Here, a form in which the substrate 110A is a plate-like member having a rectangular shape in a plan view will be described. However, the base of the spiral antenna 110 may have any shape as long as it is a member having the main surfaces 110A1 and 110A2, and may be a configuration other than a plate-like member such as a substrate.

[0076] Substrate 110A is formed of any material that is transparent to radio waves radiated from base station BS and capable of supporting first radiating section 111, second radiating section 112, and power feed line 113. "Transparent to the radiated radio waves" means, for example, that the transmission loss is 10 dB or less. "Substrate 110A is transparent to the radiated radio waves" means that the transmission loss of substrate 110A is 10 dB or less, preferably 6 dB or less, more preferably 3 dB or less, and even more preferably 1 dB or less.

[0077] Moreover, since the spiral antenna 110 is transparent to visible light, for example, the substrate 110A is transparent to visible light. "Transparent" to visible light means that the visual transmittance is at least 40% or more, preferably 60% or more, more preferably 70% or more, and further preferably 80% or more.

[0078] As an example, a resin substrate (resin film) may be used as the substrate 110A. Examples of resin materials that satisfy the above conditions include acrylic resins such as polymethyl methacrylate, cycloolefin resins, polycarbonate resins, and polyethylene terephthalate (PET). Also, a glass plate may be used as the substrate 110A. Examples of glass plates that satisfy the above conditions include soda-lime glass, alkali-free glass, Pyrex (registered trademark) glass, and quartz glass. Note that, here, as an example, a form in which the substrate 110A is a resin substrate will be described.

[0079] <First radiating portion 111> The first radiating portion 111 is provided on the main surface 110A1 of the substrate 110A, and has a feeding point 111A and an open end 111B. The first radiating portion 111 is a radiating portion that extends in a spiral shape between the feeding point 111A located on the center side in a plan view and the open end 111B located on the outside in a plan view. The feeding line 113 is also spiral in a plan view, and the first radiating portion 111 extends between the feeding line 113 from the feeding point 111A toward the open end 111B. When the antenna device 100 includes a plurality of spiral antennas 110, a reflector 130 is provided corresponding to each of the first radiating portions 111 in a front view.

[0080] The first radiating portion 111 is formed of a conductive film formed on the main surface 110A1. The conductive film constituting the first radiating portion 111 will be described later together with the conductive films constituting the second radiating portion 112 and the power feed line 113.

[0081] A portion of first radiating portion 111 between feeding point 111A and open end 111B is a logarithmic spiral portion. First radiating portion 111 is, for example, integrally formed from feeding point 111A to open end 111B.

[0082] The first radiating portion 111 has two outer edges in plan view. The two outer edges are an inner edge and an outer edge sandwiching the line width of the spiral pattern of the first radiating portion 111 in plan view.

[0083] The logarithmic spiral portion is a portion of first radiating portion 111 in which two outer edges have a shape based on a logarithmic spiral, and is a portion between feeding point 111A and open end 111B. As an example, the spiral shape of first radiating portion 111 having a logarithmic spiral portion has a shape that spirals counterclockwise from feeding point 111A on the center side toward open end 111B in a plan view seen from the +Z direction side.

[0084] The logarithmic spiral portion has a shape in which the line width becomes wider from the power supply point 111A on the center side toward the open end 111B. In addition, the inner edge and the outer edge of the first radiating portion 111 may not completely match the shape of the logarithmic spiral in a planar view, and may deviate to some extent. Since the first radiating portion 111 has a line width, the inner edge and the outer edge may be interrupted in the middle of the logarithmic spiral, particularly on the center side, and may deviate from the shape of the logarithmic spiral. In addition, the inner edge and the outer edge of the first radiating portion 111 may not completely match the shape of the logarithmic spiral in a planar view, for example, due to the relationship with the adjustment of the shape of the details when forming the first radiating portion 111 with a mesh-like metal thin film to be described later. The outer edge of the logarithmic spiral portion has a shape based on the logarithmic spiral in a planar view means that such a deviation from the strict logarithmic spiral is allowed.

[0085] Note that, as an example, a form in which first radiating section 111 includes a logarithmic spiral section having a shape based on a logarithmic spiral will be described here, but the shape of the outer edge of the spiral section included in first radiating section 111 may be a spiral shape other than a logarithmic spiral. For example, the shape of the outer edge of the spiral section included in first radiating section 111 may have a shape based on a spiral shape such as an Archimedean spiral.

[0086] <Second radiating portion 112> The second radiating portion 112 is provided on the main surface 110A2 of the substrate 110A, and has an open end 112A, a connection portion 112B, and a ground line 112C. The second radiating portion 112 is held at ground potential by connecting the ground line 112C to a shield line via a coaxial connector 155. The second radiating portion 112 overlaps with the power feed line 113 in a plan view, and forms a microstrip line together with the power feed line 113. That is, the second radiating portion 112 serves as a ground line of the microstrip line.

[0087] As an example, second radiating portion 112 has a configuration in which first radiating portion 111 is rotated 180 degrees in a plan view around the center of the spiral of first radiating portion 111 as the center of rotation, and ground line 112C is connected to connection portion 112B located at a position corresponding to open end 111B of first radiating portion 111. The shape of the section from open end 112A to connection portion 112B of second radiating portion 112 corresponds to the shape from power feed point 111A to open end 111B of first radiating portion 111. For this reason, description of the shapes of open end 112A and connection portion 112B of second radiating portion 112 will be omitted.

[0088] The second radiating portion 112 has a configuration in which the first radiating portion 111 is rotated 180 degrees in a plan view, the power feed point 111A becomes an open end 112A, and a ground line 112C is connected to a connection portion 112B corresponding to the open end 111B. The ground line 112C extends to an end portion on the -Y direction side of the substrate 110A, and is connected to a shield line of the transmission cable 150 by a coaxial connector 155. Note that, while FIG. 4C shows a configuration in which the line width of the ground line 112C is equal to the line width at the connection portion 112B of the second radiating portion 112 as an example, the line width of the ground line 112C may be narrower than the line width at the connection portion 112B as long as it is wider than the line width of the power feed line 113.

[0089] <Feeder line 113> The power supply line 113 has a connection portion 113A and an end portion 113B, and has a spiral shape in a plan view. The power supply line 113 has a constant line width from the connection portion 113A to the end portion 113B.

[0090] The connection portion 113A is connected to the feeding point 111A of the first radiating portion 111. The end portion 113B is connected to a core wire of the transmission cable 150 via a coaxial connector 155, and thereby a signal transmitted from the device body 101 is input.

[0091] In a plan view, the power supply line 113 extends in a spiral shape between the spiral portions from the power supply point 111A to the open end 111B of the first radiating section 111. The distance between the spiral portion of the power supply line 113 and the spiral portion of the first radiating section 111 becomes wider from the connection section 113A toward the end section 113B.

[0092] A spiral portion of the feed line 113 from the connection portion 113A to the end portion 113B overlaps with the second radiating portion 112 in a planar view. The feed line 113 forms a microstrip line with the second radiating portion 112 at ground potential. The length of the portion of the feed line 113 from the connection portion 113A to the end portion 113B is equal to the length from the open end 112A of the second radiating portion 112 to the end portion of the ground line 112C on the -Y direction side.

[0093] As an example, such a power feeder 113 has a shape based on a logarithmic spiral. The meaning of the power feeder 113 having a shape based on a logarithmic spiral is the same as the meaning of the first radiating section 111 having a shape based on a logarithmic spiral. For example, the logarithmic spiral may be interrupted midway on the center side, and the shape of the power feeder 113 may not completely match the shape of a logarithmic spiral in a planar view due to adjustments of the detailed shape and the like when forming the power feeder 113 from a mesh-like metal thin film, which will be described later. The power feeder 113 having a shape based on a logarithmic spiral in a planar view means that deviation from such a strict logarithmic spiral is allowed.

[0094] <Conductive Films of First Radiating Section 111, Second Radiating Section 112, and Power Supply Line 113> The first radiating section 111, the second radiating section 112, and the power supply line 113 are transparent to visible light, and are formed of, for example, a mesh-like thin metal film made of copper, nickel, gold, etc. Hereinafter, the mesh-like thin metal film may be simply referred to as a metal mesh.

[0095] As described above, the spiral antenna 110 has a luminous transmittance of 50% or more because the substrate 110A is transparent to visible light and the first radiating section 111, the second radiating section 112, and the power supply line 113 are made of a mesh-like metal thin film.

[0096] As an example, the mesh pattern of first radiating portion 111, second radiating portion 112, and power feed line 113 has a line width of 50 μm to 200 μm, a pitch of 500 μm to 2000 μm, and a thickness of 3 μm to 10 μm.

[0097] In addition, it is preferable that the mesh patterns match in the portion where the second radiating portion 112 and the power feeder 113 overlap in a plan view. This is to improve the appearance and to prevent the second radiating portion 112 above the power feeder 113 from being seen when the spiral antenna 110 is viewed from the indoor side with the concealment pattern 120 described later formed.

[0098] <Concealment Pattern 120> As shown in Fig. 4D, the concealment pattern 120 has concealment patterns 120A, 120B, and 120C. The concealment pattern 120A is an example of a first concealment pattern. The concealment pattern 120B is an example of a second concealment pattern. The concealment pattern 120C is an example of a third concealment pattern. Hereinafter, when there is no particular distinction between the concealment patterns 120A, 120B, and 120C, they will simply be referred to as the concealment patterns 120.

[0099] The concealment pattern 120 is provided to hide the metallic luster of the metal mesh of the first radiating portion 111, the second radiating portion 112, and the power feed line 113. The first radiating portion 111, the second radiating portion 112, and the power feed line 113, which are made of a metal mesh, have a metallic luster and are therefore noticeable especially when viewed from the front direction (planar view direction).

[0100] Since the spiral antenna 110 is disposed indoors at a position overlapping with the window glass 11 in a plan view, when the spiral antenna 110 is viewed from the indoor side, the surface on the +Z direction side of the second radiating section 112 (the surface in contact with the substrate 110A) is visible through the transparent substrate 110A. More specifically, the portion of the surface on the +Z direction side of the second radiating section 112 that does not overlap with the feeder line 113 in a plan view is visible.

[0101] Moreover, when looking at the spiral antenna 110 from the indoor side, the surfaces of the first radiating portion 111 and the power feed line 113 on the +Z direction side are visible. When looking at the spiral antenna 110 from the indoor side, the side surface between the surfaces of the first radiating portion 111 and the power feed line 113 on the +Z direction side and the substrate 110A may also be visible.

[0102] The concealment pattern 120 hides the metallic luster of the metal mesh, making the spiral antenna 110 less noticeable when viewed from inside the building. The concealment pattern 120 is formed by performing a blackening process on the portion of the metal mesh where the metallic luster is to be hidden. The portion where the concealment pattern 120 is provided will be described in detail later.

[0103] The blackening treatment is, for example, a coating treatment of black ink, or a treatment of forming a metal layer such as silver and then subjecting the surface to, for example, a chemical treatment to blacken the surface of the metal layer. Details of the blackening treatment will be described later.

[0104] Moreover, the first radiating portion 111, the second radiating portion 112, and the power feeder 113 are provided in a portion of the rectangular substrate 110A in plan view. Therefore, when the spiral antenna 110 is viewed from the indoor side, the portion where the first radiating portion 111, the second radiating portion 112, and the power feeder 113 are present (present portion) and the portion where they are not present (absent portion) appear differently depending on the presence or absence of metallic luster. Even if the above-mentioned blackening treatment is performed, when the spiral antenna 110 is viewed from the indoor side, the present portion and the absent portion appear differently in plan view. Therefore, the concealment pattern 120 may be provided in the absent portion where no metal mesh is present, in addition to the present portion where the metal mesh is present, of the rectangular substrate 110A in plan view.

[0105] An example of a specific configuration of the concealment patterns 120A, 120B, and 120C shown in FIG. 4D will be described below.

[0106] <Concealment Pattern 120A> The concealment pattern 120A is provided on the main surface 110A1 of the substrate 110A in a portion that overlaps only the second radiating portion 112 in a planar view, and in a portion (absent portion) where the first radiating portion 111, the second radiating portion 112, and the power supply line 113 are not present in a planar view.

[0107] A concealment pattern cannot be provided between the surface on the +Z direction side of the second radiating portion 112 and the main surface 110A2 of the substrate 110A. This is because the second radiating portion 112, which is made of mesh metal, is formed directly on the main surface 110A2. For this reason, in order to hide the second radiating portion 112 when the spiral antenna 110 is viewed from the indoor side, a concealment pattern 120A is provided in a portion of the main surface 110A1 of the substrate 110A that overlaps only with the second radiating portion 112.

[0108] In order to reduce the difference in appearance between the non-existent portion of the main surface 110A1 of the substrate 110A and the present portion, a concealment pattern is formed in the non-existent portion. Here, the non-existent portion of the main surface 110A1 is not provided with a mesh metal, similar to the portion of the main surface 110A1 that overlaps only with the second radiating portion 112, so that the concealment pattern 120A can be formed together with the portion of the main surface 110A1 that overlaps only with the second radiating portion 112.

[0109] For this reason, as an example, the concealment pattern 120A is provided on the main surface 110A1 of the substrate 110A in a portion that overlaps only with the second radiating portion 112 in a plan view and in a non-existent portion.

[0110] The concealment pattern 120A is formed by, for example, printing a silver layer on the main surface 110A1 of the substrate 110A, and then subjecting the surface of the silver layer to a blackening treatment using a chemical solution to oxidize the surface of the silver layer. The silver layer is an example of a third conductor layer. The surface of the silver layer is oxidized by the blackening treatment to become black silver oxide. Silver oxide is an example of an insulating layer. Note that, for example, the silver layer can be formed by applying a silver paste containing silver powder by a screen printing method. Also, for example, a water-soluble palladium compound or an aqueous solution of sodium hypochlorite or the like can be used as the chemical solution for the blackening treatment.

[0111] The thickness of the concealing pattern 120A is thinner than the combined thickness of the power supply line 113 and the concealing pattern 120B. The power supply line 113 and the concealing pattern 120B are formed by two screen printing processes: one for printing the power supply line 113 and the other for printing the concealing pattern 120B. In contrast, the concealing pattern 120A is formed by performing a blackening treatment using a chemical solution on a silver layer formed by one screen printing process. Therefore, the thickness of the concealing pattern 120A is thinner than the combined thickness of the power supply line 113 and the concealing pattern 120B.

[0112] The silver layer of the concealment pattern 120A is formed in a portion of the main surface 110A1 of the substrate 110A that overlaps only with the second radiating portion 112 in a plan view and in a portion where they are not present, spaced apart from the first radiating portion 111 and the power feed line 113. If the silver layer is connected to the first radiating portion 111 and the power feed line 113, this may affect the radiation characteristics of the spiral antenna 110, so the silver layer is formed in a state insulated from the first radiating portion 111 and the power feed line 113.

[0113] Moreover, the concealment pattern 120A is separated into a plurality of pattern parts insulated from each other. In other words, the concealment pattern 120A is composed of a plurality of pattern parts insulated from each other. Fig. 4D shows a configuration in which the concealment pattern 120A is separated into a plurality of pattern parts that are rectangular in plan view and have the same planar size. However, the shape of each pattern part in plan view is not limited to a rectangular shape, and the size may also be different.

[0114] If the wavelength at the operating frequency of the spiral antenna 110 is λ, the outer dimension of each pattern portion of the concealment pattern 120A is less than λ / 2. The outer dimension of each pattern portion is the maximum dimension of each pattern portion. Since the concealment pattern 120A is a thin film layer that is thin in the Z direction and extends parallel to the XY plane, the outer dimension of each pattern portion is the maximum dimension in the XY plane. In the case of a rectangular pattern portion, the maximum dimension is obtained on the diagonal line. The operating frequency of the spiral antenna 110 is the operating frequency of the first radiating portion 111 and the second radiating portion 112.

[0115] By making the outer dimensions of each pattern portion of the concealment pattern 120A less than λ / 2, it is possible to prevent each pattern portion from acting as a radiating element, and it is possible to maintain good radiation characteristics of the spiral antenna 110.

[0116] In addition, in the portion where concealment pattern 120A overlaps only with second radiating section 112 in a planar view, it has a mesh pattern that is equal in shape and size to the mesh pattern of second radiating section 112 in a planar view, and the mesh pattern of second radiating section 112 and the mesh pattern of concealment pattern 120A are consistent in a planar view.

[0117] Here, the mesh pattern of second radiating section 112 and the mesh pattern of concealment pattern 120A matching in a planar view means that the mesh patterns match each other so that, when concealment pattern 120A is viewed in a planar view from inside the room, second radiating section 112 on the back side (-Z direction) of concealment pattern 120A is not visible.

[0118] Therefore, the mesh pattern of the concealment pattern 120A has a pitch equal to the pitch of the mesh pattern of the second radiating portion 112 in a portion overlapping only with the second radiating portion 112 in a plan view, and has a line width equal to or greater than the line width of the mesh pattern of the second radiating portion 112. The mesh pattern of the concealment pattern 120A is arranged so as to overlap with the mesh pattern of the second radiating portion 112. In this way, when the concealment pattern 120A is viewed from the indoor side in a plan view, the second radiating portion 112 on the rear side is not visible. In addition, in order to make the second radiating portion 112 on the rear side of the concealment pattern 120A less visible, it is preferable to make the line width of the mesh pattern of the concealment pattern 120A thicker than that of the second radiating portion 112. Note that the presence of a positional deviation due to a manufacturing error or the like is included in the mesh patterns of the concealment pattern 120A and the second radiating portion 112 matching each other.

[0119] Furthermore, in a non-existent portion of concealment pattern 120A that does not overlap second radiating portion 112 in a plan view, the concealment pattern 120A may have a mesh pattern that is different from the mesh pattern in the portion that overlaps with second radiating portion 112, or may have the same mesh pattern. When the mesh patterns are the same, the entire concealment pattern 120A has the same mesh pattern, which makes it easy to manufacture.

[0120] Incidentally, concealment pattern 120A does not have to be provided in the non-existent portion. For example, in a state in which concealment pattern 120A is provided in a portion overlapping only with second radiating portion 112 in a plan view, and concealment patterns 120B and 120C are provided overlapping power feeder 113 and first radiating portion 111, when spiral antenna 110 is viewed from the indoor side, if the non-existent portion is difficult to stand out, concealment pattern 120A does not have to be provided in the non-existent portion.

[0121] Alternatively, the concealment pattern 120A may be a concealment pattern formed by a blackening process in which black ink containing carbon is applied in a mesh pattern by screen printing. The black ink is an example of an insulating layer. The mesh pattern of the concealment pattern 120A may match the mesh pattern of the second radiating portion 112 at least in the portion where the second radiating portion 112 is present in a plan view. The matching of the mesh patterns is the same as the matching of the mesh pattern of the concealment pattern 120A, which is made up of a silver layer and a silver oxide layer, with the mesh pattern of the second radiating portion 112.

[0122] Furthermore, when the concealment pattern 120A is composed of a black ink layer applied in a mesh pattern, it is not necessary to separate the concealment pattern 120A into a plurality of pattern parts as shown in Fig. 4D. This is because black ink does not contain conductive material and has almost no effect on the radiation characteristics of the spiral antenna 110. The blackening process of applying black ink will be described later using the concealment pattern 120B.

[0123] Also, the concealment pattern 120A may be a concealment pattern made of a silver layer and a silver oxide layer in a portion where the second radiating portion 112 exists in a plan view, and a concealment pattern made of black ink in a portion where the second radiating portion 112 does not exist. Conversely, the concealment pattern 120A may be a concealment pattern made of black ink in a portion where the second radiating portion 112 exists in a plan view, and a concealment pattern made of a silver layer and a silver oxide layer in a portion where the second radiating portion 112 does not exist.

[0124] <Concealment Pattern 120B> The concealing pattern 120B is provided on the surface of the power supply line 113. The surface of the power supply line 113 on which the concealing pattern 120B is provided is the surface of the power supply line 113 excluding the portion in contact with the substrate 110A.

[0125] The surface of the power supply line 113 on which the concealment pattern 120B is provided includes the surface on the +Z direction side of the power supply line 113, and may further include a side surface located between the surface on the +Z direction side and the substrate 110A. That is, the concealment pattern 120B is provided on the surface on the +Z direction side of the power supply line 113, and may be provided on not only the surface on the +Z direction side of the power supply line 113 but also a side surface located between the surface on the +Z direction side and the substrate 110A.

[0126] Since the power feeder 113 is formed of a mesh-like metal thin film such as copper, nickel, or gold, the concealing pattern 120B is formed by a blackening process in which black ink is applied, rather than a blackening process using a chemical solution. Since the power feeder 113 is formed of a mesh metal provided on the main surface 110A1 of the substrate 110A, providing a concealing pattern 120A made of a silver layer and a silver oxide layer to hide the power feeder 113 may affect the impedance characteristics of the power feeder 113 and the radiation characteristics of the spiral antenna 110. For this reason, the concealing pattern 120B is formed of black ink.

[0127] More specifically, as an example, the concealment pattern 120B can be formed by applying black ink by a screen printing method to the surface of the power supply line 113 provided on the substrate 110A. In this case, the concealment pattern 120B is formed on the surface on the +Z direction side of the power supply line 113, and may also be formed on at least a part of the side surface located between the surface on the +Z direction side and the substrate 110A.

[0128] The black ink may contain a black pigment such as carbon black, titanium, etc. The black ink is preferably one capable of forming a coating film exhibiting high electrical insulation properties.

[0129] The concealing pattern 120B is formed of black ink applied to the surface of the mesh-like metal thin film of the power supply line 113, so that the concealing pattern 120B is formed in a mesh shape along the mesh pattern of the power supply line 113.

[0130] Providing such concealment pattern 120B makes it possible to make power feeder 113 less noticeable. Since the mesh patterns of power feeder 113 and second radiating section 112 match, the portion of second radiating section 112 that overlaps with power feeder 113 in plan view is not subjected to blackening treatment, but is hardly visible when spiral antenna 110 is viewed from the indoor side, and is hardly noticeable.

[0131] The concealment pattern 120B formed with black ink has almost no effect on the impedance characteristics of the feeder line 113, the radiation characteristics of the spiral antenna 110, and the like.

[0132] <Concealment Pattern 120C> The concealment pattern 120C is provided on the surface of the first radiating portion 111. The surface of the first radiating portion 111 on which the concealment pattern 120C is provided is the surface of the first radiating portion 111 excluding the portion in contact with the substrate 110A.

[0133] The surface of first radiating section 111 on which concealment pattern 120C is provided includes the surface on the +Z direction side of first radiating section 111, and may further include a side surface located between the surface on the +Z direction side and substrate 110A. That is, concealment pattern 120C is provided on the surface on the +Z direction side of first radiating section 111, and may be provided on, in addition to the surface on the +Z direction side of first radiating section 111, also on a side surface located between the surface on the +Z direction side and substrate 110A.

[0134] Since the first radiating portion 111 is formed of a mesh-shaped metal thin film such as copper, nickel, or gold, the concealing pattern 120C is formed by a blackening process in which black ink is applied, rather than a blackening process using a chemical solution. Since the first radiating portion 111 is formed of a mesh metal provided on the main surface 110A1 of the substrate 110A, providing a concealing pattern 120A made of a silver layer and a silver oxide layer to hide the first radiating portion 111 may affect the radiation characteristics of the first radiating portion 111. For this reason, the concealing pattern 120C is formed of black ink.

[0135] More specifically, as an example, the concealment pattern 120C can be formed by applying black ink by a screen printing method to the surface of the first radiating portion 111 provided on the substrate 110A. In this case, the concealment pattern 120C is formed on the surface on the +Z direction side of the first radiating portion 111, and may also be formed on at least a part of a side surface located between the surface on the +Z direction side and the substrate 110A.

[0136] The concealment pattern 120C is formed of black ink applied to the surface of the mesh-shaped metal thin film of the first radiating portion 111, so that the concealment pattern 120C is formed in a mesh shape along the mesh pattern of the first radiating portion 111.

[0137] Providing such a concealing pattern 120C makes it difficult to stand out the first radiating portion 111. The concealing pattern 120C formed with black ink has almost no effect on the impedance characteristics of the first radiating portion 111, the radiation characteristics of the spiral antenna 110, and the like.

[0138] <Measurement results> 5 is a diagram showing an example of the measurement results of the antenna device 100. For comparison, measurements were also performed on antenna devices A, B, and C under the same conditions.

[0139] Antenna device A does not include concealment patterns 120A, 120B, and 120C, and has a silver layer that is not divided in a planar view formed over the entire inside of the non-existent portion, and a silver oxide layer provided on the surface on the +Z direction side. In other words, antenna device A has a configuration in which concealment pattern 120A and concealment patterns 120B and 120C in the portion where second radiating portion 112 is present in a planar view are omitted from antenna device 100, and concealment pattern 120A inside the non-existent portion is integrated without being divided.

[0140] Antenna device B is an antenna device in which concealment pattern 120A is formed only in the non-existent portion, and does not include concealment patterns 120B and 120C. Concealment pattern 120A of antenna device B is not formed in the portion where second radiating portion 112 is present in plan view.

[0141] Antenna device C has a configuration in which all of the concealment patterns 120A, 120B, and 120C are omitted from antenna device 100.

[0142] A signal was input to end 113B of feeder line 113 and the intensity (dB) of the reflected wave returning to end 113B was measured for antenna device 100 and comparative antenna devices A to C. The frequency of the signal input to end 113B was changed from 0.1 GHz to 5 GHz.

[0143] 5, the horizontal axis represents the frequency (GHz) of the signal input to end portion 113B, and the vertical axis represents the intensity (dB) of the reflected wave. Note that the characteristics of antenna device C, which does not include concealment patterns 120A, 120B, and 120C, are characteristics that serve as a comparison standard for antenna device 100 and comparative antenna devices A and B.

[0144] 5, it was confirmed that the characteristics of antenna device A are significantly different from those of antenna device C, and that the strength of the reflected wave is higher than that of antenna device A, which has a significant effect on the radiation characteristics of spiral antenna 110. In particular, in the bands of around 1.5 GHz, around 2.3 GHz, around 3.5 GHz, and around 4.6 GHz where the strength of the reflected wave of antenna device C is low, the strength of the reflector of antenna device A is significantly higher than the strength of the reflected wave of antenna device C.

[0145] The characteristics of the antenna device 100 and the antenna device B are similar to those of the antenna device C, and the strength of the reflected wave is low in the bands of around 0.6 GHz, around 1.7 GHz, around 2.3 GHz, around 3.5 GHz, and around 4.6 GHz, where the strength of the reflected wave of the antenna device C is low, and a band of -10 dB or less was obtained. Furthermore, no significant difference was observed in the characteristics of the antenna device 100 and the antenna device B.

[0146] From the above, it was found that even if the concealment pattern 120A divided so that the outer dimension is less than λ / 2 is provided in the non-existent portion as in the antenna device B, the radiation characteristics of the spiral antenna 110 are hardly affected.

[0147] Furthermore, since the difference in characteristics between antenna device 100 and antenna device B is small, it was found that providing a concealment pattern 120A not only in the non-existent parts but also in the parts where the second radiating section 112 is provided in a planar view, as in antenna device 100, has almost no effect on the radiation characteristics of spiral antenna 110.

[0148] 4D, a configuration has been described in which concealment pattern 120A, which is obtained by performing a blackening process on the surface of a silver layer, is formed on main surface 110A1 of substrate 110A, and concealment patterns 120B and 120C, which are formed by a blackening process of applying black ink, are formed on the surfaces of feeder 113 and first radiating portion 111. However, the blackening process for hiding the metal mesh is not limited to this configuration, and may be a blackening process as shown in FIGS. 6A to 6F.

[0149] <Variations of blackening treatment (part 1): Figures 6A and 6B> Fig. 6A is a diagram showing an example of the configuration of antenna 110M1 before blackening processing is performed, and Fig. 6B is a diagram showing an example of a variation (part 1) of the blackening processing.

[0150] 6A is an antenna that can be used in place of the spiral antenna 110 in the antenna device 100. The antenna 100M1 has a substrate 110A, a conductor pattern 115, and a conductor pattern 116. The substrate 110A is the same as the substrate 110A of the spiral antenna 110, and has a main surface 110A1 on the indoor side and a main surface 110A2 on the outdoor side.

[0151] Conductive patterns 115 are formed on main surface 110A1. Fig. 6A shows three conductive patterns 115 as an example. Conductive pattern 116 is formed on main surface 110A2. Fig. 6A shows two conductive patterns 116 as an example. The three conductive patterns 115 and the two conductive patterns 116 are located at different positions in a plan view.

[0152] The three conductor patterns 115 and the two conductor patterns 116 are all formed of a mesh-like metal thin film such as copper, nickel, or gold. A total of five conductor patterns, the three conductor patterns 115 and the two conductor patterns 116, are conductor patterns included in the antenna 110M1. The five conductor patterns include a radiating portion of the antenna 110M1, and may further include a ground layer, a power feed line, or the like.

[0153] Since the three conductor patterns 115 and the two conductor patterns 116 are positioned differently in a plan view, when viewing the antenna 110M1 from inside the building, the surfaces of the two conductor patterns 116 that are in contact with the main surface 110A1 can be seen through the substrate 110A between the three conductor patterns 115.

[0154] In such a case, as one example, the concealing pattern 120A may be formed by applying black ink by screen printing to the portions of the main surface 110A1 of the substrate 110A that overlap with the two conductor patterns 116, and the concealing pattern 120B may be formed by applying black ink to the surfaces of the three conductor patterns 115. As one example, the concealing pattern 120B may be formed on the surface and side surface on the +Z direction side of the three conductor patterns 115. The concealing pattern 120A is an example of a first concealing pattern, and the concealing pattern 120B is an example of a second concealing pattern. Moreover, the conductor pattern 115 is an example of a first conductor pattern, and the conductor pattern 116 is an example of a second conductor pattern.

[0155] As described above, the conductive patterns 115 and 116 are concealed by the concealment patterns 120A and 120B formed by applying black ink, making the antenna 110M1 less noticeable even when viewed from inside the building.

[0156] <Variations of Blackening Treatment (Part 2): Figures 6A, 6C, 6D, and 6E> 6C, 6D, and 6E are diagrams showing an example of a variation of the blackening process (part 2). FIG. 6A is used here.

[0157] In the blackening variation (part 2), a silver layer is formed and then a blackening process using a chemical solution is performed to create a concealing pattern.

[0158] First, as shown in Fig. 6C, two silver layers 121 are formed on a portion of the main surface 110A1 of the substrate 110A of the antenna 110M1 shown in Fig. 6A that overlaps with the two conductor patterns 116 in a plan view. The silver layers 121 can be produced, for example, by applying a silver paste by a screen printing method.

[0159] Next, the antenna 110M1 shown in Fig. 6C is immersed in a chemical solution to oxidize the surface of the silver layer 121, and a black silver oxide layer 122 is formed on the surface of the silver layer 121 as shown in Fig. 6D. In this manner, a concealment pattern 120A consisting of the silver layer 121 and the silver oxide layer 122 can be produced. The concealment pattern 120A is an example of a first concealment pattern, and the conductor pattern 116 is an example of a second conductor pattern.

[0160] After producing the concealing pattern 120A, as shown in Fig. 6E, the surfaces of the three conductor patterns 115 are coated with black ink by screen printing to form the concealing pattern 120B. The concealing pattern 120B is an example of a second concealing pattern, and the conductor pattern 115 is an example of a first conductor pattern. Note that the concealing pattern 120B may be formed by screen printing only on the surface of the conductor pattern 115 on the +Z direction side.

[0161] As described above, the conductor patterns 115 and 116 are concealed by the concealment pattern 120A formed by forming the silver layer 121 and then oxidizing the surface with a chemical solution, and the concealment pattern 120B formed by applying black ink, making the antenna 110M1 less noticeable even when viewed from inside the building.

[0162] <Variations of the blackening process (part 3): Figures 6A, 6C, and 6F> Fig. 6F is a diagram showing an example of a variation (part 3) of the blackening process. Fig. 6A is used here.

[0163] In the blackening variation (part 3), the conductor patterns 115 and 116 in FIG. 6A are made of silver.

[0164] As shown in Fig. 6C, two silver layers 121 are formed on a portion of the main surface 110A1 of the substrate 110A of the antenna 110M1 shown in Fig. 6A that overlaps with the two conductor patterns 116 in a plan view. The silver layers 121 can be produced, for example, by applying a silver paste by a screen printing method.

[0165] Next, when antenna 110M1 is immersed in a chemical solution, silver conductor patterns 115 and 116 and the surface of silver layer 121 are oxidized, and as shown in Fig. 6F, concealment patterns 120B and 120D composed of black silver oxide layers are formed on the surfaces of conductor patterns 115 and 116, and a black silver oxide layer 122 is formed on the surface of silver layer 121. Silver layer 121 and silver oxide layer 122 constitute concealment pattern 120A.

[0166] Concealing pattern 120A is an example of a first concealing pattern, and conductor pattern 116 is an example of a second conductor pattern. Concealing pattern 120B is an example of a second concealing pattern, and conductor pattern 115 is an example of a first conductor pattern.

[0167] As described above, when the conductor patterns 115 and 116 are made of silver, the silver layer 121 is formed and then the surface is oxidized using a chemical solution, thereby forming a concealment pattern 120A consisting of the silver layer 121 and the silver oxide layer 122, a concealment pattern 120B on the surface of the conductor pattern 115, and a concealment pattern 120D on the surface of the conductor pattern 116.

[0168] The conductor patterns 115 and 116 are concealed by the concealment patterns 120A and 120B, so that the antenna 110M1 is less noticeable when viewed from the indoor side. Also, a concealment pattern 120D can be formed on the surface of the conductor pattern 116 on the outdoor side.

[0169] <Modifications of the Antenna of the Antenna Device 100> 7A and 7B are diagrams showing an example of the configuration of a patch antenna 210. The patch antenna 210 can be used as an antenna of the antenna device 100 in place of the spiral antenna 110.

[0170] The patch antenna 210 has substrates 110A and 110B, a conductor pattern 212, a feed line 213, a patch conductor 214, and concealment patterns 220A and 220B. Fig. 7B shows the positional relationship between the conductor pattern 212, the feed line 213, and the patch conductor 214 when viewed from the +Z direction side.

[0171] The substrate 110A is an example of a base. The substrate 110B is an example of a second base. The conductor pattern 212 is an example of a second conductor pattern. The power supply line 213 is an example of a first conductor pattern. The patch conductor 214 is an example of a resonant element. The concealment pattern 220A is an example of a first concealment pattern. The concealment pattern 220B is an example of a second concealment pattern.

[0172] As with the spiral antenna 110, the patch antenna 210 is, for example, attached to the window glass 11 by a fixing member such as a holder so as to be parallel to the main surface 11A (see FIG. 2A) of the window glass 11 and with a gap of about 10 mm between the main surface 11A and the patch antenna 210. As with the holder that fixes the spiral antenna 110, such a holder is, for example, made of resin that is transparent to visible light.

[0173] <Substrates 110A and 110B> The substrates 110A and 110B are fixed by a holder (not shown) so as to be parallel to the main surface 11A (see FIG. 2A) of the window glass 11 and spaced apart from each other at a predetermined interval. The substrate 110A is located closer to the indoor side than the substrate 110B, and the substrate 110B is located closer to the outdoor side (closer to the window glass 11) than the substrate 110A. The substrates 110A and 110B are, for example, equal in size in a plan view, and are, for example, arranged with their positions aligned in a plan view. The substrates 110A and 110B are, for example, equal in size in a plan view to the size of the conductor pattern 212 in a plan view. However, the substrates 110A and 110B may be different in size in a plan view.

[0174] The substrate 110A has an indoor main surface 110A1 and an outdoor main surface 110A2. The substrate 110B has an indoor main surface 110B1 and an outdoor main surface 110B2.

[0175] <Conductor pattern 212> Conductive pattern 212 has slot 212A and is formed over the entire main surface 110A2 of substrate 110A. Conductive pattern 212 is made of a mesh-like metal thin film such as copper, nickel, or gold. Slot 212A is an opening provided in the center in plan view. Slot 212A has a rectangular shape in plan view, and has a longitudinal direction along the X direction, for example. Conductive pattern 212 is connected to a shield wire of transmission cable 150 (see FIG. 2A) and is held at ground potential.

[0176] The slot 212A is electromagnetically coupled to the feed line 213 on the +Z direction side, and is also electromagnetically coupled to the patch conductor 214 on the -Z direction side. When power is fed from the feed line 213, the slot 212A is excited in the Y direction and operates as a slot antenna, thereby functioning as a slot power feeding section and feeding the patch conductor 214. This is the operation when a radio wave is radiated from the patch conductor 214. The operation when the patch conductor 214 receives a radio wave is the opposite of the operation during radiation. The longitudinal direction of the slot 212A may be parallel to the Y direction, or may be configured to have an angle that is oblique to the X and Y directions.

[0177] <Feeder line 213> The power feed line 213 is formed on the main surface 110A1 of the substrate 110A. The power feed line 213 extends from an end on the +Y direction side of the main surface 110A1 in the center in the X direction of the main surface 110A1 to the -Y direction side of the end on the -Y direction side of the slot 212A in a planar view. Therefore, as shown in FIG. 7B, in a planar view, the power feed line 213 straddles the slot 212A in the Y direction and has a portion overlapping with the slot 212A. The end on the +Y direction side of the power feed line 213 is connected to the signal line of the transmission cable 150.

[0178] The power supply line 213 is made of a mesh-like thin metal film of copper, nickel, gold, etc. Since the power supply line 213 overlaps with the conductor pattern 212 in a plan view, the mesh pattern of the power supply line 213 matches the mesh pattern of the conductor pattern 212.

[0179] <Patch conductor 214> The patch conductor 214 is provided on the principal surface 110B1 of the substrate 110B. For example, the patch conductor 214 is provided in the center of the principal surface 110B1 in plan view, and for example, has a rectangular shape in plan view. The patch conductor 214 is made of a mesh-like metal thin film such as copper, nickel, or gold.

[0180] Since the patch conductor 214 overlaps with the conductor pattern 212 and the feed line 213 , the mesh pattern of the patch conductor 214 matches the mesh pattern of the conductor pattern 212 and the feed line 213 .

[0181] 7B, the patch conductor 214 includes the slot 212A in a plan view. The patch conductor 214 including the slot 212A in a plan view means that the outer edge of the patch conductor 214 includes the outer edge of the slot 212A in a plan view. The shape of the patch conductor 214 in a plan view is not limited to a rectangular shape, and may be a circular shape, an elliptical shape, or the like. Although a form in which the patch conductor 214 includes the slot 212A in a plan view will be described here, the positional relationship between the patch conductor 214 and the slot 212A in a plan view is not limited to such a positional relationship. It is sufficient that a part of the patch conductor 214 overlaps with the slot 212A in a plan view.

[0182] The patch conductor 214 is coupled to the slot 212A, and is excited in the Y direction similarly to the slot 212A. When the longitudinal direction of the slot 212A is parallel to the Y direction, the patch conductor 214 is excited in the X direction together with the slot 212A. When the longitudinal direction of the slot 212A is oblique to the X and Y directions, the patch conductor 214 is excited in a direction perpendicular to the longitudinal direction of the slot 212A in plan view. A concealment pattern may be provided on the surface and side surface on the +Z direction side of the patch conductor 214, or on the surface on the +Z direction side.

[0183] <Concealment Pattern 220A> The concealment pattern 220A is provided on the main surface 110A1 of the substrate 110A. More specifically, the concealment pattern 220A is provided in a portion that overlaps with the conductor pattern 212, which is an example of the second conductor pattern, in a plan view, excluding a portion where the power supply line 113 and the slot 212A are present.

[0184] The concealment pattern 220A is separated into a plurality of pattern parts each having an outer dimension of less than λ / 2. The concealment pattern 220A has a silver layer 221 and a silver oxide layer 222. The silver layer 221 and the silver oxide layer 222 correspond to the silver layer 121 and the silver oxide layer 122 shown in FIG. 6D, respectively. Each pattern part of the concealment pattern 220A has a configuration in which the silver oxide layer 222 is formed on the surface of the silver layer 221 provided on the main surface 110A1. The silver oxide layer 222 may be formed on a side surface located between the surface on the +Z direction side of the silver layer 221 and the substrate 110A, in addition to the surface on the +Z direction side of the silver layer 221.

[0185] The concealment pattern 220A is formed, similarly to the concealment pattern 120A shown in FIG. 4D, by, for example, printing a silver layer 221 on the main surface 110A1 of the substrate 110A, and subjecting the silver layer 211 to a blackening treatment using a chemical solution to produce a silver oxide layer 222.

[0186] The concealment pattern 220A has a mesh pattern that is equal in shape and size to the mesh pattern of the conductor pattern 212 in a planar view, and the mesh pattern of the conductor pattern 212 and the mesh pattern of the concealment pattern 220A match in a planar view. The mesh patterns of the conductor pattern 212 and the concealment pattern 220A matching in a planar view has the same meaning as the mesh patterns of the second radiating portion 112 and the concealment pattern 120A matching in a planar view.

[0187] The concealment pattern 220A is provided in a portion that overlaps with the conductor pattern 212 in a plan view, excluding the portion where the power supply line 113 and the slot 212A are present. Therefore, when the concealment pattern 220A is viewed in a plan view from the indoor side, it is possible to hide the conductor pattern 212 on the rear side.

[0188] A concealing pattern cannot be provided between the surface of the conductor pattern 212 on the +Z direction side and the main surface 110A2 of the substrate 110A. This is because the conductor pattern 212 made of mesh metal is formed directly on the main surface 110A2. For this reason, a concealing pattern 220A is provided in a portion of the main surface 110A1 of the substrate 110A that overlaps with the conductor pattern 212 so that the conductor pattern 212 is hidden when the patch antenna 210 is viewed from the indoor side.

[0189] The concealment pattern 220A may be a concealment pattern formed by a blackening process in which black ink is applied in a mesh pattern by a screen printing method. The mesh pattern of the concealment pattern 220A may match the mesh pattern of the conductor pattern 212 in a plan view. The matching of the mesh patterns has the same meaning as the matching of the mesh pattern of the concealment pattern 220A, which is composed of the silver layer 221 and the silver oxide layer 222, with the mesh pattern of the conductor pattern 212.

[0190] When the concealment pattern 220A is formed of a mesh-like black ink layer, it is not necessary to separate the concealment pattern 220A into multiple pattern parts as shown in Fig. 7B because the black ink does not contain a conductive material and has almost no effect on the radiation characteristics of the spiral antenna 110.

[0191] <Concealment Pattern 220B> The concealing pattern 220B is provided on the surface of the power supply line 213. The surface of the power supply line 213 on which the concealing pattern 220B is provided is the surface of the power supply line 213 excluding the portion in contact with the substrate 110A.

[0192] Concealment pattern 220B is provided on the surface on the +Z direction side of power supply line 213, and in addition to the surface on the +Z direction side, may also be provided on a side located between the surface on the +Z direction side and substrate 110A.

[0193] Since the power supply line 213 is formed of a mesh-like metal thin film such as copper, nickel, or gold, the concealing pattern 220B is formed by a blackening process in which black ink is applied, rather than a blackening process using a chemical solution. Since the power supply line 213 is formed of a mesh metal provided on the main surface 110A1 of the substrate 110A, providing a concealing pattern 220A made of a silver layer and a silver oxide layer to hide the power supply line 213 may affect the impedance characteristics of the power supply line 213 and the radiation characteristics of the patch antenna 210. For this reason, the concealing pattern 220B is formed of black ink. The concealing pattern 220B is formed in a mesh shape along the mesh pattern of the power supply line 213.

[0194] Providing such a concealment pattern 220B can make the power feeder 213 less noticeable. Since the mesh patterns of the power feeder 213, the conductor pattern 212, and the patch conductor 214 match each other, within the range in which the concealment pattern 220B is provided, the conductor pattern 212 and the patch conductor 214 are hardly visible and hardly noticeable even when the patch antenna 210 is viewed from the indoor side.

[0195] The concealment pattern 220B formed with black ink has almost no effect on the impedance characteristics of the feeder line 213 or the radiation characteristics of the patch antenna 210, etc.

[0196] The above-described patch antenna 210 may be used in place of the spiral antenna 110.

[0197] <Effects> The antenna device 100 includes a substrate 110A (base) having an indoor main surface 110A1 (first main surface) and an outdoor main surface 110A2 (second main surface), a feeder 113 (first conductor pattern) formed on the main surface 110A1, a second radiating portion 112 (second conductor pattern) formed on the main surface 110A2, and a concealment pattern 120A (first concealment pattern) formed on the main surface 110A1 at a position overlapping with the second radiating portion 112 in a plan view, the second radiating portion 112 and the concealment pattern 120A have mesh patterns formed in a mesh shape in a plan view, and the mesh pattern of the second radiating portion 112 and the mesh pattern of the concealment pattern 120A match each other in a plan view. Therefore, when the antenna device 100 is viewed from the indoor side, the mesh pattern of the second radiating portion 112 can be hidden by the concealment pattern 120A to make it less noticeable.

[0198] Therefore, it is possible to provide an antenna device 100 with a good appearance.

[0199] Moreover, concealment pattern 120A is separated into a plurality of pattern parts insulated from each other, and the outer dimension of each pattern part may be less than λ / 2, where λ is the wavelength at the operating frequency of second radiating part 112. When concealment pattern 120A includes a conductor, by making the outer dimension of each pattern part less than λ / 2, it is possible to prevent each pattern part from acting as a radiating element, and good radiation characteristics of spiral antenna 110 can be maintained.

[0200] The mesh pattern of second radiating portion 112 may have a line width of 50 μm to 200 μm, a pitch of 500 μm to 2000 μm, and a thickness of 3 μm to 10 um. A fine mesh-like metal thin film is a transparent conductor, but by hiding the metallic luster of second radiating portion 112 made of such a mesh-like metal thin film with concealment pattern 120A, it is possible to provide antenna device 100 with a better appearance.

[0201] In addition, it may further include a concealing pattern 120B (second concealing pattern) formed so as to overlap the power supply line 113. The power supply line 113 can be hidden by the concealing pattern 120B, making it less noticeable.

[0202] Furthermore, the thickness of the concealing pattern 120A may be thinner than the combined thickness of the power supply line 113 and the concealing pattern 120B. The power supply line 113 and the concealing pattern 120B are formed by two screen printing operations, whereas the concealing pattern 120A is formed by performing a blackening treatment with a chemical solution on a silver layer formed by one screen printing operation, so that the thickness of the concealing pattern 120A is thinner than the combined thickness of the power supply line 113 and the concealing pattern 120B. The concealing pattern 120A can be formed using less material than the concealing pattern 120B, which allows for cost reduction.

[0203] Furthermore, the power feeder 113 and the concealment pattern 120B have a mesh pattern formed in a mesh shape in a planar view, and the mesh pattern of the power feeder 113 and the mesh pattern of the concealment pattern 120B may match in a planar view. The mesh-shaped concealment pattern 120B can make the mesh-shaped power feeder 113 less visible, thereby providing an antenna device 100 with a better appearance.

[0204] The concealment pattern 120A may be formed of an insulating layer formed on the main surface 110A1 by blackening. The concealment pattern 120A formed of an insulating layer is easy to fabricate. Furthermore, the concealment pattern 120A formed of an insulating layer has almost no effect on the radiation characteristics, so it can be arranged at a position overlapping the second radiating portion 112 without considering the radiation characteristics of the second radiating portion 112, and there is a high degree of freedom in arrangement.

[0205] The insulating layer formed by the blackening process may be a black ink layer (insulating layer) containing carbon or titanium. The concealment pattern 120B made of a black ink layer can be easily produced by screen printing.

[0206] Moreover, the concealment pattern 120A may have a third conductor layer formed on the main surface 110A1 and an insulating layer formed on the third conductor layer by blackening treatment. By having an insulating layer formed on the third conductor layer by blackening treatment, the concealment pattern 120A can hide the second radiating portion 112. Moreover, by dividing the concealment pattern 120A into a plurality of pattern portions and setting the outer dimensions of each pattern portion to less than λ / 2, it is possible to prevent each pattern portion from acting as a radiating element, and it is possible to provide an antenna device 100 that looks good and has good radiation characteristics.

[0207] Moreover, the third conductor layer may be a conductive layer containing silver, and the insulating layer formed by the blackening treatment may be an insulating layer containing silver oxide. By performing a blackening treatment using a chemical solution on the surface of the silver layer 121, the black silver oxide layer 122 can be easily produced. Moreover, by separating the concealment pattern 120A into a plurality of pattern parts and making the outer dimension of each pattern part less than λ / 2, it is possible to prevent each pattern part from acting as a radiating element, and it is possible to provide an antenna device 100 that looks good and has good radiation characteristics.

[0208] Moreover, the concealing pattern 120B may be formed of an insulating layer formed by blackening treatment so as to overlap the power supply line 113. The power supply line 113 can be hidden by the concealing pattern 120B formed of an insulating layer that has little effect on the impedance characteristics of the power supply line 113.

[0209] Furthermore, the substrate 110A may be transparent to visible light, making the substrate 110A inconspicuous and providing an antenna device 100 with a good appearance.

[0210] Furthermore, the substrate 110A may be a glass substrate or a resin substrate. The substrate 110A made of a glass substrate or a resin substrate is inconspicuous, making it possible to provide an antenna device 100 with a good appearance.

[0211] The second conductor pattern may be a spiral radiating portion of a spiral antenna (second radiating portion 112) or a slot antenna (conductor pattern 212 having slots 212A). By hiding the second conductor pattern constituted by the second radiating portion 112 or the slot antenna with the concealment pattern 120A, it is possible to provide an antenna device 100 with a good appearance.

[0212] The second conductor pattern is a slot antenna (conductor pattern 212 having slot 212A), and power feeder 213 is a power feeder that feeds power to the slot antenna, and slot 212A of the slot antenna and power feeder 213 may have an overlapping portion in plan view. In a configuration in which slot 212A and power feeder 213 have an overlapping portion in plan view, by hiding the second conductor pattern constituted by the slot antenna with concealment pattern 120A, it is possible to provide antenna device 100 with a good appearance.

[0213] The antenna device 100 further includes a patch conductor 214 (resonant element) arranged on the opposite side of the slot antenna (conductor pattern 212 having slot 212A) to the feed line 213, and the patch conductor 214 (resonant element) may overlap with the slot 212A of the slot antenna in a plan view. By feeding power to the patch conductor 214 by making the slot antenna having the slot 212A function as a slot feeding section, it is possible to transmit and receive radio waves via the patch conductor 214. In such a configuration, by hiding the second conductor pattern formed by the slot antenna with the concealment pattern 120A, it is possible to provide an antenna device 100 with a good appearance.

[0214] The spiral antenna 110 may further include a first spiral radiating portion 111 formed on the main surface 110A1, the first conductive pattern being a spiral feeder line 113 connected to a feed point of the first radiating portion 111, and the second conductive pattern being a second spiral radiating portion 112 of the spiral antenna that is provided overlapping the feeder line 113 in a plan view, and the first radiating portion 111, the feeder line 113, and the second radiating portion 112 may form the spiral antenna 110. By hiding the second radiating portion 112 of the spiral antenna 110 with the concealment pattern 120A, it is possible to provide an antenna device 100 that looks good.

[0215] The spiral antenna 110 may further include a concealment pattern 120C (third concealment pattern) formed to overlap with the first radiating portion 111. By concealing the second radiating portion 112 of the spiral antenna 110 with the concealment pattern 120A and concealing the first radiating portion 111 with the concealment pattern 120C, it is possible to provide an antenna device 100 that looks good.

[0216] Furthermore, first radiating portion 111 and concealment pattern 120C have mesh patterns formed in a mesh shape in a planar view, and the mesh pattern of first radiating portion 111 and the mesh pattern of concealment pattern 120C may match in a planar view. By matching the mesh patterns, first radiating portion 111 can be made more difficult to see by concealment pattern 120C, and an antenna device 100 with a better appearance can be provided.

[0217] Second radiating portion 112 may transmit and receive radio waves in the Sub-6 band or millimeter wave band. By concealing second radiating portion 112 that transmits and receives radio waves in the Sub-6 band or millimeter wave band with concealment pattern 120A, it is possible to provide antenna device 100 with a good appearance.

[0218] Furthermore, antenna device 100 may be placed indoors. When antenna device 100 placed indoors is viewed from the indoor side, the mesh pattern of second radiating portion 112 can be hidden by concealment pattern 120A to make it less noticeable.

[0219] Wireless communication device 200 includes the above-mentioned antenna device 100, and communication device 180 that performs wireless communication via power feeder 113 or second radiating section 112. Therefore, when antenna device 100 is viewed from the indoor side, the mesh pattern of second radiating section 112 can be hidden by concealing pattern 120A, making it less noticeable.

[0220] Therefore, it is possible to provide a wireless communication device 200 that looks good.

[0221] Although exemplary antenna devices and wireless communication devices of the present disclosure have been described above, the present disclosure is not limited to the specifically disclosed embodiments, and various modifications and variations are possible without departing from the scope of the claims.

[0222] Regarding the above embodiment, the following supplementary notes are further disclosed. (Appendix 1) A base having a first main surface on an indoor side and a second main surface on an outdoor side; A first conductor pattern formed on the first main surface; A second conductor pattern formed on the second main surface; a first concealment pattern formed on the first principal surface at a position overlapping with the second conductor pattern in a plan view; Including, the second conductor pattern and the first concealment pattern have a mesh pattern formed in a mesh shape in a plan view, The antenna device, wherein the mesh pattern of the second conductor pattern and the mesh pattern of the first concealment pattern coincide with each other in a plan view. (Appendix 2) The first concealment pattern is divided into a plurality of pattern portions that are insulated from each other, 2. The antenna device according to claim 1, wherein, when a wavelength at an operating frequency of the first conductor pattern or the second conductor pattern is λ, an outer dimension of each pattern portion is less than λ / 2. (Appendix 3) 3. The antenna device according to claim 1, wherein the mesh pattern of the second conductor pattern has a line width of 50 μm to 200 μm, a pitch of 500 μm to 2000 μm, and a thickness of 3 μm to 10 um. (Appendix 4) The antenna device according to any one of claims 1 to 3, further comprising a second concealment pattern formed so as to overlap the first conductor pattern. (Supplementary Note 5) The antenna device described in claim 14, wherein a thickness of the first concealment pattern is thinner than a total thickness of the first conductor pattern and the second concealment pattern. (Appendix 6) the first conductor pattern and the second concealment pattern have a mesh pattern formed in a mesh shape in a plan view, 6. The antenna device according to claim 5, wherein a mesh pattern of the first conductor pattern and a mesh pattern of the second concealment pattern coincide with each other in a planar view. (Appendix 7) 7. The antenna device according to claim 1, wherein the first concealment pattern is formed of an insulating layer formed on the first principal surface by a blackening process. (Appendix 8) 8. The antenna device according to claim 7, wherein the insulating layer formed by the blackening treatment is an insulating layer containing carbon. (Appendix 9) The first concealment pattern is A third conductor layer formed on the first main surface; an insulating layer formed on the third conductor layer by blackening treatment; 7. The antenna device according to claim 1, further comprising: (Appendix 10) the third conductor layer is a conductive layer containing silver, 10. The antenna device according to claim 9, wherein the insulating layer formed by the blackening treatment is an insulating layer containing silver oxide. (Appendix 11) 7. The antenna device according to claim 5, wherein the second concealment pattern is composed of an insulating layer formed on the first conductor pattern by a blackening process. (Appendix 12) 12. The antenna device according to any one of claims 1 to 11, wherein the base is transparent to visible light. (Appendix 13) 13. The antenna device according to claim 1, wherein the base is a glass substrate or a resin substrate. (Appendix 14) 14. The antenna device according to claim 1, wherein the second conductor pattern is a spiral radiating portion of a spiral antenna or a slot antenna. (Appendix 15) the second conductor pattern is a slot antenna, the first conductor pattern is a feeder line that feeds power to the slot antenna, 15. The antenna device according to claim 14, wherein the slot of the slot antenna and the feed line have an overlapping portion in a planar view. (Appendix 16) a resonant element disposed on an opposite side of the slot antenna from the feed line, 16. The antenna device according to claim 15, wherein the resonant element overlaps with the slot of the slot antenna in a planar view. (Appendix 17) The first radiating portion further includes a spiral radiating portion formed on the first main surface, the first conductor pattern is a spiral feed line connected to a feed point of the first radiation portion, the second conductor pattern is a spiral second radiation portion of the spiral antenna and is provided so as to overlap with the power feed line in a plan view; 17. The antenna device according to claim 14, wherein the first radiating portion, the feed line, and the second radiating portion configure a spiral antenna. (Appendix 18) 18. The antenna device of claim 17, further comprising a third concealment pattern formed over the first radiating portion. (Appendix 19) the first radiation portion and the third concealment pattern have a mesh pattern formed in a mesh shape in a plan view, 19. The antenna device according to claim 18, wherein a mesh pattern of the first radiating portion and a mesh pattern of the third concealment pattern coincide with each other in a planar view. (Appendix 20) 20. The antenna device according to any one of claims 1 to 19, wherein the first conductor pattern or the second conductor pattern transmits or receives radio waves in the Sub-6 band or the millimeter wave band. (Appendix 21) 21. The antenna device according to claim 1, which is arranged indoors. (Appendix 22) An antenna device according to any one of Supplementary Notes 1 to 21; a communication device that performs wireless communication via the first conductor pattern or the second conductor pattern; 23. A wireless communication device comprising: [Explanation of symbols]

[0223] 10. Windows 11 Window Glass 11A main surface 11B Main surface 50 Smartphone 100 Antenna device 100M1 Antenna 101 Device body 110 Spiral antenna (An example of an antenna) 110A Substrate (an example of a substrate) 110A1 Principal surface (an example of the first principal surface) 110A2 Main surface (an example of the second main surface) 110B Substrate (an example of a second substrate) 110B1 Main surface 110B2 Main surface 111 First radiation part (an example of the first radiation part) 112 Second radiation portion (an example of a second conductor pattern) 113 Power supply line (an example of the first conductor pattern) 113A Connection 113B End 115 Conductive pattern (an example of a first conductive pattern) 116 Conductor pattern (an example of a second conductor pattern) 120 Concealment Pattern 120A Concealment Pattern (an example of the first concealment pattern) 120B Concealment pattern (an example of the second concealment pattern) 120C Concealment pattern (an example of the third concealment pattern) 120D Concealment Pattern 121 Silver layer (an example of the third conductor layer) 122 Silver oxide layer (an example of an insulating layer) 130 Reflector 131 Substrate 132 Reflecting conductor 140 Matching layer 150 Transmission cable 155 Coaxial Connector 180 Communication Equipment 200 Wireless communication device 210 Patch antenna (An example of an antenna) 211 Silver layer 212 Conductor pattern (an example of a second conductor pattern) 212A Slot 213 Power supply line (an example of the first conductor pattern) 214 Patch conductor (an example of a resonant element) 220A Concealment pattern (an example of the first concealment pattern) 220B Concealment pattern (an example of the second concealment pattern) 221 Silver layer 222 Silver oxide layer

Claims

1. A base having a first main surface on an indoor side and a second main surface on an outdoor side; A first conductor pattern formed on the first main surface; A second conductor pattern formed on the second main surface; a first concealment pattern formed on the first principal surface at a position overlapping with the second conductor pattern in a plan view; Including, the second conductor pattern and the first concealment pattern have a mesh pattern formed in a mesh shape in a plan view, An antenna device, wherein a mesh pattern of the second conductor pattern and a mesh pattern of the first concealment pattern coincide with each other in a planar view.

2. The first concealment pattern is divided into a plurality of pattern portions insulated from each other, 2. The antenna device according to claim 1, wherein, when a wavelength at an operating frequency of the first conductor pattern or the second conductor pattern is λ, an outer dimension of each pattern portion is less than λ / 2.

3. 2. The antenna device according to claim 1, wherein the mesh pattern of the second conductor pattern has a line width of 50 μm to 200 μm, a pitch of 500 μm to 2000 μm, and a thickness of 3 μm to 10 μm.

4. The antenna device according to claim 1 , further comprising a second concealment pattern formed to overlap the first conductor pattern.

5. The antenna device according to claim 4 , wherein a thickness of the first concealment pattern is smaller than a total thickness of the first conductor pattern and the second concealment pattern.

6. the first conductor pattern and the second concealment pattern have a mesh pattern formed in a mesh shape in a plan view, The antenna device according to claim 5 , wherein a mesh pattern of the first conductor pattern and a mesh pattern of the second concealment pattern coincide with each other in a plan view.

7. The antenna device according to claim 1 , wherein the first concealment pattern is made of an insulating layer formed on the first main surface by a blackening process.

8. 8. The antenna device according to claim 7, wherein the insulating layer formed by the blackening treatment is an insulating layer containing carbon.

9. The first concealment pattern is A third conductor layer formed on the first main surface; an insulating layer formed on the third conductor layer by blackening treatment; 7. An antenna arrangement according to claim 1, further comprising:

10. the third conductor layer is a conductive layer containing silver, 10. The antenna device according to claim 9, wherein the insulating layer formed by the blackening treatment is an insulating layer containing silver oxide.

11. The antenna device according to claim 5 , wherein the second concealment pattern is made of an insulating layer formed by blackening on the first conductor pattern.

12. The antenna device according to claim 1 , wherein the substrate is transparent to visible light.

13. The antenna device according to claim 1 , wherein the base is a glass substrate or a resin substrate.

14. The antenna device according to claim 1 , wherein the second conductor pattern is a spiral radiating portion of a spiral antenna or a slot antenna.

15. the second conductor pattern is a slot antenna, the first conductor pattern is a feeder line that feeds power to the slot antenna, The antenna device according to claim 14 , wherein the slot of the slot antenna and the feed line have an overlapping portion in a plan view.

16. a resonant element disposed on an opposite side of the slot antenna from the feed line, The antenna device according to claim 15 , wherein the resonant element overlaps with the slot of the slot antenna in a plan view.

17. The first radiating portion further includes a spiral radiating portion formed on the first main surface, the first conductor pattern is a spiral feed line connected to a feed point of the first radiation portion, the second conductor pattern is a spiral second radiation portion of the spiral antenna and is provided so as to overlap with the power feed line in a plan view, The antenna device according to claim 14 , wherein the first radiating portion, the feed line, and the second radiating portion form a spiral antenna.

18. The antenna device according to claim 17 , further comprising a third concealment pattern formed to overlap the first radiating portion.

19. The first radiation portion and the third concealment pattern have a mesh pattern formed in a mesh shape in a plan view, The antenna device according to claim 18 , wherein a mesh pattern of the first radiating portion and a mesh pattern of the third concealment pattern coincide with each other in a plan view.

20. 2. The antenna device according to claim 1, wherein the first conductor pattern or the second conductor pattern transmits or receives radio waves in the Sub-6 band or the millimeter wave band.

21. The antenna device according to claim 1 , which is arranged indoors.

22. An antenna device according to claim 1; a communication device that performs wireless communication via the first conductor pattern or the second conductor pattern; 23. A wireless communication device comprising:

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