Vehicle antenna device

Abstract

The present invention is provided with the function of an antenna and another electrical function different from that of an antenna.　Provided is a vehicle antenna apparatus comprising: a first dielectric plate having a main surface; a second dielectric plate disposed directly or indirectly at the main surface of the first dielectric plate; a first electrically conductive layer disposed between a first intermediate film and a second intermediate film between the first dielectric plate and the second dielectric plate; an electrically conductive frame disposed between the first dielectric plate and the first intermediate film, between the second dielectric plate and the second intermediate film, or on the opposite side from the main surface relative to the second dielectric plate, the electrically conductive frame having an inner edge following an outer edge of the first electrically conductive layer in plan view of the first dielectric plate; an electric power feed unit electrically connected to the electrically conductive frame; and a voltage control unit electrically connected to the first electrically conductive layer, the voltage control unit including an electric power supply and controlling a voltage applied to the first electrically conductive layer. The electrically conductive frame has a lower electrical resistance than the first electrically conductive layer, and functions as a part of an antenna for transmitting and receiving a radio wave in a prescribed frequency band.

Description

[Technical Field]

[0001] The present disclosure relates to a vehicle antenna device. [Background technology]

[0002] BACKGROUND ART Conventionally, in laminated glass for automobiles, a technology has been known in which a heating element for melting ice adhering to the wiper blades is enclosed inside an interlayer film sandwiched between two glass sheets (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2020 / 003902 Summary of the Invention [Problem to be solved by the invention]

[0004] Patent Document 1 describes that the electric element placed inside the interlayer film is an antenna element, a photochromic element, or a light-emitting sheet instead of a heating element. However, depending on the size of the glass plate, it may be difficult to use an electric element having an electrical function different from that of the antenna element in combination with the antenna element.

[0005] The present disclosure provides a vehicle antenna device that combines an antenna function with an electrical function other than the antenna function. [Means for solving the problem]

[0006] In one aspect of the present disclosure, a first dielectric plate having a main surface; a second dielectric plate disposed directly or indirectly on the main surface of the first dielectric plate; a first conductive layer disposed between a first intermediate film and a second intermediate film between the first dielectric plate and the second dielectric plate; a conductive frame disposed between the first dielectric plate and the first intermediate film, between the second dielectric plate and the second intermediate film, or on the opposite side of the second dielectric plate from the main surface, the conductive frame having an inner edge that follows an outer edge of the first conductive layer in a plan view of the first dielectric plate; a power supply portion electrically connected to the conductive frame; a voltage control unit electrically connected to the first conductive layer, including a power source, and controlling a voltage applied to the first conductive layer; Equipped with The conductive frame has a lower electrical resistance than the first conductive layer and functions as a part of an antenna that transmits and receives radio waves in a predetermined frequency band, thereby providing a vehicle antenna device.

[0007] In another aspect of the present disclosure, a first dielectric plate having a main surface; a second dielectric plate disposed directly or indirectly on the main surface of the first dielectric plate; a first conductive layer disposed between a first intermediate film and a second intermediate film between the first dielectric plate and the second dielectric plate; a second conductive layer disposed between the first intermediate film and the first dielectric plate and having a lower electrical resistance than the first conductive layer; a power supply portion electrically connected to a conductor region of the second conductive layer that is located outside the first conductive layer in a plan view of the first dielectric plate; a voltage control unit electrically connected to the first conductive layer, including a power source, and controlling a voltage applied to the first conductive layer; Equipped with The second conductive layer functions as a part of an antenna that transmits and receives radio waves in a predetermined frequency band, thereby providing a vehicle antenna device. In this specification, the term "directly or indirectly disposed" means disposed on the main surface without any other layer or member therebetween, or disposed on the main surface via any other layer or member. [Effects of the Invention]

[0008] According to the technology of the present disclosure, it is possible to provide a vehicle antenna device that combines an antenna function with an electrical function other than the antenna function. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a plan view showing a configuration example of a vehicle antenna device according to a first embodiment. [Figure 2] 1 is an exploded perspective view showing a configuration example of a vehicle antenna device according to a first embodiment. [Figure 3] FIG. 1 is a diagram showing an example of the cross-sectional structure of a window glass equipped with a light control film inside. [Figure 4] 10 is an enlarged plan view illustrating an example of overlap between a conductive layer and a conductive frame. FIG. [Figure 5] 10A and 10B are diagrams illustrating two paths extending from a power supply portion along the outer edge of a conductive frame to a ground conductor portion. [Figure 6] 10A and 10B are diagrams illustrating two paths from a power supply portion along the outer edge of a conductive frame to a connection portion. [Figure 7] FIG. 10 is an exploded perspective view showing a configuration example of a vehicle antenna device according to a second embodiment. [Figure 8] FIG. 10 is an exploded perspective view showing a configuration example of a vehicle antenna device according to a third embodiment. [Figure 9] FIG. 2 is a plan view of a simulation model of the vehicle antenna device. [Figure 10] 10 is a diagram showing an example of a simulation result of a reflection coefficient S11 versus a clockwise path length DCW from a power feed portion along an outer edge of the conductive frame to a ground conductor portion in the vehicle antenna device of the first embodiment. FIG. [Figure 11] 10 is a diagram showing an example of a simulation result of a reflection coefficient S11 versus a counterclockwise path length DCCW from a feeder along an outer edge of a conductive frame to a ground conductor in the vehicle antenna device of the first embodiment. FIG. [Figure 12]FIG. 11 is a diagram showing an example of a simulation result of the reflection coefficient S11 versus the clockwise path length DCW from the power supply portion along the outer edge of the conductor region to the ground conductor portion in a plan view of the glass plate in the vehicle antenna device of the third embodiment. [Figure 13] FIG. 11 is a diagram showing an example of a simulation result of the reflection coefficient S11 versus the counterclockwise path length DCCW from the power supply portion along the outer edge of the conductor region to the ground conductor portion in a plan view of the glass plate in the vehicle antenna device of the third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] Several embodiments according to the present disclosure will be described below with reference to the drawings. To facilitate understanding of each embodiment, the scale of each part in the drawings may differ from the actual scale. In this specification, directions such as "parallel," "right angle," "orthogonal," "horizontal," "vertical," "up / down," and "left / right" are permitted to deviate to the extent that they do not impair the functions and effects of the embodiments. The shape of corners is not limited to right angles and may be rounded like an arch. In this specification, the "X-axis direction," "Y-axis direction," and "Z-axis direction" refer to directions parallel to the X-axis, the Y-axis, and the Z-axis, respectively. The X-axis, Y-axis, and Z-axis directions are mutually orthogonal. In this specification, the "XY plane," "YZ plane," and "ZX plane" refer to imaginary planes parallel to the X-axis and Y-axis directions, imaginary planes parallel to the Y-axis and Z-axis directions, and imaginary planes parallel to the Z-axis and X-axis directions, respectively.

[0011] Examples of vehicle window glass used in the vehicle antenna devices according to various embodiments of the present disclosure include rear glass attached to the rear of the vehicle, windshield attached to the front of the vehicle, side glass attached to the side of the vehicle, roof glass attached to the ceiling of the vehicle, etc. The vehicle window glass is not limited to these examples.

[0012] Fig. 1 is a plan view showing an example of the configuration of a vehicle antenna device of the first embodiment. The antenna device 201 shown in Fig. 1 is a vehicle antenna device including a vehicle window glass 101 and a voltage control unit 110. Fig. 1 illustrates the window glass 101 attached to a window frame 63 formed in a body part 62 that is a part of a vehicle 60, as viewed from the inside of the vehicle. With the window glass 101 attached to the window frame 63, the positive side of the Z-axis direction represents the inside of the vehicle, and the negative side of the Z-axis direction represents the outside of the vehicle.

[0013] The vehicle window glass of the first embodiment is particularly suitable for use in a window glass (for example, a side window) that is installed substantially parallel to a vertical direction perpendicular to a horizontal plane, in that it improves the receiving sensitivity (antenna gain) of both vertically polarized waves and horizontally polarized waves. Fig. 1 shows an example in which window glass 101 is applied to a side window of a vehicle.

[0014] The window frame 63 is a conductive portion that can be grounded and is also called a flange. The window frame 63 has a frame 61 that forms an opening that is covered by the window glass 101. Figure 1 shows frame sides 61a, 61b, 61c, and 61d. The frame 61 is an example of the inner edge of the window frame 63.

[0015] The window glass 101 has an outer peripheral edge 13 including outer edges 13a, 13b, 13c, and 13d. The window glass 101 is attached to the window frame 63 so that the outer peripheral edge 13 overlaps the window frame 63 in a plan view from inside the vehicle, and the outer edges 13a, 13b, 13c, and 13d are attached to the corresponding frame sides 61a, 61b, 61c, and 61d, respectively. When the window glass 101 attached to the window frame 63 is viewed from inside the vehicle, the outer edges 13a, 13b, 13c, and 13d are hidden by the vehicle body 62 or the window frame 63, but are shown by solid lines in FIG. 1 for convenience.

[0016] 2 is an exploded perspective view showing an example of the configuration of the vehicle antenna device of Embodiment 1. In the vehicle antenna device 201, the window glass 101 is a laminated glass mainly including a glass plate 10, a glass plate 20, a conductive layer 30, an interlayer film 40, a conductive frame 70, and a power supply part 80.

[0017] The glass plate 10 is a plate-shaped dielectric having a main surface 11 facing the positive side in the Z-axis direction and a main surface 12 facing the opposite side of the main surface 11 in the Z-axis direction (the negative side in the Z-axis direction). The glass plate 10 may be transparent or translucent. The main surface 11 is the surface facing the inside of the vehicle, and the main surface 12 is the surface facing the outside of the vehicle. The glass plate 10 is an example of a first dielectric plate or a first glass plate, which will be described later.

[0018] The glass plate 20 is arranged with the main surface 11 facing the glass plate 10. The glass plate 20 is a plate-shaped dielectric having a main surface 14 facing the positive side in the Z-axis direction and a main surface 15 facing the opposite side from the main surface 14 in the Z-axis direction. The glass plate 20 may be transparent or translucent. The main surface 14 is the surface facing the inside of the vehicle, and the main surface 15 is the surface facing the outside of the vehicle. The glass plate 20 is an example of a second dielectric plate or a second glass plate, which will be described later.

[0019] The conductive layer 30 is a conductor disposed between the intermediate film 40A and the intermediate film 40B between the glass plate 10 and the glass plate 20. The conductive layer 30 is a planar conductor facing the main surface 11 of the glass plate 10. The conductive layer 30 may be transparent or translucent. Specific examples of the conductive layer 30 include a metal film such as an Ag (silver) film, a metal oxide film such as an ITO (indium tin oxide) film, a resin film containing conductive particles, and a laminate of multiple types of films. The conductive layer 30 may be a resin film such as polyethylene terephthalate coated by vapor deposition or the like. The conductive layer 30 may be a film formed into a mesh shape by conductive ink or etching. The conductive layer 30 is an example of a first conductive layer, which will be described later.

[0020] The conductive layer 30 is, for example, a conductive film included in a light control film that actively changes the visible light transmittance of the opening of the window glass 101 by applying an AC voltage.

[0021] FIG. 3 is a cross-sectional view schematically illustrating an example of the laminated structure of window glass incorporating a light control film. The light control film 120 illustrated in FIG. 3 is sandwiched between an intermediate film 40A and an intermediate film 40B. The light control film 120 includes resin substrates 121 and 122 facing each other between the intermediate film 40A and the intermediate film 40B, a light control layer 123 disposed between the resin substrates 121 and 122, and conductive films 124 and 125 formed on the respective main surfaces of the resin substrates 121 and 122. The light control layer 123 is a molecular layer having optical anisotropy. The conductive films 124 and 125 are an example of a conductive layer 30. Light control by the light control film 120 functions by applying a voltage between the pair of conductive films 124 and 125.

[0022] The resin substrates 121, 122 are made of, for example, a transparent resin. The resin substrates 121, 122 include, for example, polyethylene terephthalate (PET), polycarbonate (PC), or cycloolefin polymer (COP). The resin substrates 121, 122 may be made by combining two or more of these resins. The thickness of each of the resin substrates 121, 122 is, for example, in the range of 5 μm to 500 μm, preferably in the range of 10 μm to 200 μm, and more preferably in the range of 50 μm to 150 μm.

[0023] The conductive films 124, 125 are conductors included in the light control film and may include, for example, transparent conductive oxide, transparent conductive polymer, a laminated film of a metal layer and a dielectric layer, silver nanowires, or a metal mesh of silver or copper, etc. The thickness of each of the conductive films 124, 125 may be, for example, in the range of 200 nm to 2 μm.

[0024] Examples of molecules having optical anisotropy include liquid crystals. That is, for example, a liquid crystal layer may be used as a molecular layer having optical anisotropy. Examples of liquid crystal layers include polymer dispersed liquid crystals (PDLCs), polymer network liquid crystals (PNLCs), and guest-host liquid crystals. Alternatively, iodine or the like may be used as a molecule having optical anisotropy. The light management film may have a suspended particle device (SPD) including such a molecular layer.

[0025] The conductive layer 30 is not limited to the conductor contained in the light control film, and may have other functions as long as it is a conductive layer. For example, the conductive layer 30 may have a function of preventing icing or fogging of the window glass 101 by generating heat when a voltage is applied.

[0026] In FIG. 2 , the interlayer film 40 is a transparent or semi-transparent dielectric material interposed between the glass plate 10 and the glass plate 20. The glass plate 10 and the glass plate 20 are bonded together by the interlayer film 40. Examples of the interlayer film 40 include thermoplastic polyvinyl butyral (PVB) and ethylene vinyl acetate copolymer (EVA). The relative dielectric constant of the interlayer film 40 is preferably 2.4 or more and 3.5 or less. The interlayer film 40 includes an interlayer film 40A and an interlayer film 40B, and a conductive layer 30 is provided between the interlayer film 40A and the interlayer film 40B. The interlayer film 40A is an example of a first interlayer film described later, and is interposed between the glass plate 10 and the conductive layer 30. The interlayer film 40B is an example of a second interlayer film described later, and is interposed between the glass plate 20 and the conductive layer 30.

[0027] 1 and 2, the conductive frame 70 is a frame-shaped conductor arranged on the opposite side of the glass plate 20 from the main surface 11. The conductive frame 70 may be arranged, for example, in direct contact with the main surface 14 of the glass plate 20, or may be arranged indirectly on the main surface 14 via a dielectric (not shown). The conductive frame 70 has an inner edge 71 that follows the outer edge 31 of the conductive layer 30 in a plan view of the glass plate 10. The conductive frame 70 is formed of, for example, copper, silver, or the like.

[0028] The conductive frame 70 may be disposed between the glass plate 10 and the interlayer 40A, or may be disposed between the glass plate 20 and the interlayer 40B. Regardless of the position at which the conductive frame 70 is disposed, the conductive frame 70 has an inner edge 71 that follows the outer edge 31 of the conductive layer 30 in a plan view of the glass plate 10.

[0029] In FIG. 1 , the power supply unit 80 is an example of a power supply unit electrically connected to the conductive frame 70, and is, for example, a power supply electrode. The power supply unit 80 is provided near the outer edge 13 of the glass plate 20 so as to be located near the window frame 63 when the window glass 101 is attached to the window frame 63. The power supply unit 80 is electrically connected to one end of a power supply line 90 or an input terminal of an amplifier via a conductive member such as a connector. The other end of the power supply line 90 or an output terminal of the amplifier is connected to, for example, a communication device such as a receiver. The power supply line 90 is, for example, a coaxial cable having a signal line 91 and a grounding portion 92. The grounding portion 92 may be a shielded wire. One end of the signal line 91 is electrically connected to the power supply unit 80, and one end of the grounding portion 92 is grounded via the vehicle body 62 (which may be the window frame 63). The power supply line 90 may be a microstrip line.

[0030] Power supply unit 80 may protrude outside conductive frame 70 in a plan view of glass plate 20. This embodiment makes it easy to bring one end of power supply line 90 (one end of signal line 91) or a conductive member such as a connector that electrically connects an input terminal of the amplifier to power supply unit 80 into contact with power supply unit 80. The shape of power supply unit 80 is preferably a rectangular shape such as a square, an approximately square, a rectangle, or an approximately rectangular shape for implementation, but is not limited to these, and other shapes such as a circle, an approximately circle, an ellipse, or an approximately ellipse are also possible.

[0031] The voltage control unit 110 is electrically connected to the conductive layer 30 and controls the voltage applied to the conductive layer 30. The voltage control unit 110 is, for example, a control unit that includes a power source 111. For example, if the conductive layer 30 is the conductive films 124 and 125 of the light control film 120 in FIG. 3, the power source 111 applies a voltage 112 with a predetermined cycle to the conductive film 124, and applies a voltage 113 whose phase is inverted relative to the voltage 112 to the conductive film 125. As a result, an AC voltage is applied between the conductive films 124 and 125, and light control by the light control film 120 is controlled.

[0032] 1 and 2 , the conductive frame 70 has an inner edge 71 that runs along the outer edge 31 of the conductive layer 30, and is therefore electrically connected to the conductive layer 30 by capacitive coupling. Therefore, by attaching the window glass 101 to a conductive window frame 63, the conductive layer 30 and the conductive frame 70 can function as antenna conductors for the patch antenna, and the vehicle body 62 and the window frame 63 can function as grounds for the patch antenna. Because the conductive layer 30 and the conductive frame 70 function as antenna conductors, high-frequency current generated in the conductive frame 70 running along the outer edge 31 of the conductive layer 30 can be extracted from the power supply unit 80 electrically connected to the conductive frame 70. Furthermore, since the conductive frame 70 has lower electrical resistance than the conductive layer 30, high-frequency current generated in the conductive frame 70 running along the outer edge 31 of the conductive layer 30 can easily flow, thereby improving the antenna gain of a patch antenna that uses the conductive layer 30 and the conductive frame 70 as antenna conductors. An example of an index for evaluating the level of "electrical resistance" referred to here is sheet resistance (unit: Ω / □).

[0033] Alternatively, by attaching the window glass 101 to a conductive window frame 63, the conductive frame 70 functions as part of a slot antenna that uses the gap between the conductive frame 70 and the window frame 63 (when viewed in a plane of the window glass 101) as a slot.

[0034] Thus, according to the first embodiment, the conductive layer 30 and the conductive frame 70 each function as part of a patch antenna that transmits and receives (either one or both of transmission and reception) radio waves in a predetermined frequency band. Alternatively, the conductive frame 70 functions as part of a slot antenna that transmits and receives radio waves in a predetermined frequency band. Therefore, even if a conductive layer 30 with a relatively high electrical resistance is used, an antenna device 201 can be provided that can transmit and receive radio waves in a predetermined frequency band with high gain.

[0035] Hereinafter, an antenna that uses the conductive frame 70 will be referred to as the antenna ANT. The antenna ANT operates using the power supply unit 80 as a power supply point. The antenna ANT may be used as a receiving antenna that receives radio waves outside the vehicle, such as broadcast waves, or as a wireless communication antenna that transmits and receives radio waves to and from communication equipment outside the vehicle.

[0036] The antenna ANT is configured to be capable of transmitting and receiving radio waves in the VHF (Very High Frequency) band, which has a frequency of, for example, 30 MHz to 300 MHz. Specific examples of frequency bands included in the VHF band include the FM broadcast wave band (e.g., 76 MHz to 108 MHz) and the DAB Band III band (e.g., 170 MHz to 240 MHz).

[0037] The antenna ANT may be an antenna configured to transmit and receive radio waves in the UHF (Ultra High Frequency) band, which has a frequency range of 300 MHz to 3 GHz. A specific example of a frequency band included in the UHF band is the band of terrestrial digital television broadcast waves (e.g., 470 MHz to 713 MHz).

[0038] When the conductive frame 70 has a closed loop shape, high frequency current flows more easily through the conductive frame 70, improving the antenna gain of the antenna ANT. However, a notch may be formed in part of the conductive frame 70. The shape of the conductive frame 70 is not limited to a substantially rectangular shape, and may be another polygonal shape such as a substantially triangular shape.

[0039] When the power supply section 80 is placed near the corner 73a of the conductive frame 70, it is located near the frame section 70a extending in the X-axis direction (e.g., horizontal direction) and the frame section 70c extending in the Y-axis direction (e.g., up and down direction), thereby improving the antenna gain for both horizontally polarized waves and vertically polarized waves.

[0040] Furthermore, when the power supply unit 80 is disposed near the corner 73a of the conductive frame 70, the direction of the electric field generated in each of the frame units 70a and 70b facing each other in the Y-axis direction is aligned to the positive or negative side of the Y-axis direction, and the direction of the electric field generated in each of the frame units 70c and 70d facing each other in the X-axis direction is aligned to the positive or negative side of the X-axis direction over a wider range. By aligning the directions of the electric fields in this way, the radiation efficiency of the antenna ANT is improved.

[0041] Furthermore, frame portions 70a and 70b extending in the X-axis direction generate an electric field in the Y-axis direction, and frame portions 70c and 70d extending in the Y-axis direction generate an electric field in the X-axis direction. Therefore, by arranging power supply portion 80 near corner portion 73a, it becomes easy to receive electric fields in the X-axis direction and the Y-axis direction, and therefore the antenna gain for both horizontally polarized waves and vertically polarized waves is improved even in an installation environment where window glass 101 is tilted with respect to a horizontal or vertical plane.

[0042] Note that power supply unit 80 may be disposed near other corners (for example, corner 73b, corner 73c, or corner 73d) of conductive frame 70. According to this embodiment, the antenna gain for both horizontally polarized waves and vertically polarized waves is improved, similar to when power supply unit 80 is disposed near corner 73a.

[0043] The length of the frame portion 70a extending from the corner portion 73a in the X-axis direction is L X , the distance from the corner 73a in the X-axis direction is D X Then, the vicinity of the corner 73a is defined as 0≦D X ≦(1 / 3)×L X The length of the frame portion 70c extending from the corner portion 73a in the Y-axis direction is defined as L Y , the distance from the corner 73a in the Y-axis direction is D Y Then, the vicinity of the corner 73a is defined as 0≦D Y ≦(1 / 3)×LY The vicinity of other corners of the conductive frame 70 (for example, corner 73b, corner 73c, or corner 73d) is defined in a similar manner.

[0044] That is, when the power supply unit 80 is located near the corner 73a (the power supply unit 80 is located within the length L from the corner 73a to the frame 70a), X or the position within 1 / 3 of the length L from the corner 73a to the frame 70c Y When the frame 70a is positioned within one-third of the center of the antenna, the antenna gain for both horizontally polarized waves and vertically polarized waves is improved. In this case, the frame 70a is an example of a first side (described later) that extends from the corner in a first direction, and the frame 70c is an example of a second side (described later) that extends from the corner in a second direction.

[0045] The window glass 101 may also be attached to the window frame 63 so that the main surfaces 11, 12 are approximately horizontal. In this case, approximately horizontal or approximately horizontal direction refers to a range of ±30° or less with respect to the horizontal plane, but may also be a range of ±15° or less, ±10° or less, ±5° or less, or ±3° or less. An example of the window glass 101 that is attached so that the main surfaces 11, 12 are approximately horizontal is a roof glass.

[0046] In the case of a window glass 101 that is attached so that the main surfaces 11 and 12 are substantially horizontal, the antenna ANT can receive any polarized wave (e.g., linearly polarized wave, circularly polarized wave, etc.) arriving from the vertical direction (zenith direction). In particular, the antenna ANT may be an antenna that transmits and receives radio waves for satellite communication (e.g., radio waves arriving as circularly polarized waves). The antenna ANT may be configured to receive GNSS signals in a predetermined frequency band. The predetermined frequency band may be the 1.2 GHz band or the 1.6 GHz band. The 1.2 GHz band may be, for example, 1.226 GHz to 1.228 GHz, and the 1.6 GHz band may be, for example, 1.559 GHz to 1.606 GHz. Furthermore, the antenna ANT may be configured to receive SDARS (Satellite Digital Audio Radio Service) signals in the 2.3 GHz S-band (2.320 GHz to 2.345 GHz).

[0047] When the sheet resistance of the conductive layer 30 is 300 Ω / □ (ohms per square) or less, the gain of the antenna ANT is improved. In terms of improving the gain of the antenna ANT, the sheet resistance of the conductive layer 30 is preferably 200 Ω / □ or less, more preferably 100 Ω / □ or less, and even more preferably 80 Ω / □ or less. The lower limit of the sheet resistance of the conductive layer 30 should be greater than the sheet resistance of the conductive frame 70, and is, for example, preferably 5 Ω / □ or more, more preferably 10 Ω / □ or more, and even more preferably 15 Ω / □ or more.

[0048] It is sufficient that the upper limit of the sheet resistance of the conductive frame 70 is smaller than the sheet resistance of the conductive layer 30. In terms of improving the gain of the antenna ANT, for example, it is preferable that the upper limit be 2 [Ω / □] or less, and more preferably 1 [Ω / □] or less. In this way, the electrical resistance of the conductive frame 70 and the conductive layer 30 can be compared using, for example, the sheet resistance as an index.

[0049] When the window glass 101 is attached to the vehicle body 62 at a distance that allows capacitive coupling between the conductive frame 70 and the vehicle body 62, the gain of the antenna ANT can be improved. This is because high-frequency current generated around the conductive frame 70 flows to the vehicle body 62 via this capacitive coupling, expanding the area of ​​the conductor region through which the high-frequency current flows. For example, if the coupling capacitance between the conductive frame 70 of the antenna ANT and the vehicle body 62 is 0.4 pF or greater, the gain of the antenna ANT can be improved. To increase the gain of the antenna ANT, the lower limit of the coupling capacitance is preferably 1.0 pF or greater, and more preferably 2.0 pF or greater. The upper limit of the coupling capacitance is not particularly specified, but can be set to, for example, 200 pF or less.

[0050] The antenna gain of the antenna ANT is improved when the frame 61 of the window frame 63 has a portion that coincides with at least a part of the outer edge 72 of the conductive frame 70 in a plan view of the glass plate 10, or a portion that is located outside at least a part of the outer edge 72 of the conductive frame 70. In the example shown in Fig. 1 , the entire frame 61 is located outside the entire outer edge 72 in a plan view of the glass plate 10.

[0051] For example, when the opposing distance between the frame 61 of the window frame 63 and the outer edge 72 of the conductive frame 70 (for example, the opposing distance between the frame side 61b of the window frame 63 and the outer edge 72 of the frame portion 70b) is 0 mm or more and 50 mm or less when viewed in a plane of the glass plate 10, the antenna gain of the antenna ANT is improved.

[0052] FIG. 4 is an enlarged plan view illustrating the overlap between the conductive layer and the conductive frame. When the inner edge 71 of the conductive frame 70 is closer to the outer edge 31 of the conductive layer 30 in a plan view of the glass plate 10, the antenna gain of the antenna ANT is improved. For example, when at least a portion of the conductive frame 70 overlaps with the conductive layer 30 in a plan view of the glass plate 10 and the outer edge 72 of the conductive frame 70 is located within 10 mm outward from the outer edge 31 of the conductive layer 30, the antenna gain of the antenna ANT is improved. In this case, the distance d between the outer edge 72 of the conductive frame 70 and the outer edge 31 of the conductive layer 30 is preferably 10 mm or less. Furthermore, from the viewpoint of improving the antenna gain of the antenna ANT, the distance d is preferably 5 mm or less. Furthermore, from the viewpoint of improving the antenna gain of the antenna ANT, the distance d is preferably 1 mm or more.

[0053] Furthermore, when the conductive frame 70 does not overlap the conductive layer 30 in a plan view of the glass plate 10 and the inner edge 71 of the conductive frame 70 is located within 5 mm outward from the outer edge 31 of the conductive layer 30, the antenna gain of the antenna ANT is improved. From the viewpoint of improving the antenna gain of the antenna ANT, the distance between the inner edge 71 of the conductive frame 70 and the outer edge 31 of the conductive layer 30 is preferably 3 mm or less, more preferably 1 mm or less, and most preferably 0 mm. The width of the conductive frame 70 can be set appropriately regardless of whether it overlaps at least a portion of the conductive layer 30, and may be, for example, 1 mm to 20 mm, 2 mm to 15 mm, 3 mm to 10 mm, or 3 mm to 7 mm.

[0054] 1, in order for the conductive frame 70 to resonate at high frequencies, it is preferable that half the length (L / 2) of the perimeter L of the outer edge 72 of the conductive frame 70 approximately equals "λ / 4×k×(2×N-1)." Here, λ is the wavelength in air of radio waves in the frequency band transmitted and received by the conductive frame 70 (antenna ANT), k is the wavelength shortening rate determined by the glass plates 10 and 20, and N is an integer equal to or greater than 1. However, because the size of the window frame 63 differs depending on the vehicle model, half the length (L / 2) of the perimeter L of the conductive frame 70 may not approximately equal "λ / 4×k×(2×N-1)."

[0055] To address such a situation, the window glass 101 according to the first embodiment may include a ground conductor 75 at a location away from the power supply unit 80, as shown in FIG. 1 . The ground conductor 75 is an example of a ground conductor that is electrically connected to the conductive frame 70 and has a potential equivalent to earth. The ground conductor 75 is, for example, an earth electrode that is electrically connected to earth potential. By adjusting the position of the ground conductor 75 that is electrically connected to earth potential (for example, the earth potential of the vehicle body 62 or the window frame 63), the position of the antinode of the standing wave generated along the conductive frame 70 can be adjusted to the position of the ground conductor 75. This makes it possible to easily adjust the position of the antinode of the standing wave generated along the conductive frame 70 to the position of the power supply unit 80, thereby improving the antenna gain of the antenna ANT.

[0056] The ground conductor 75 may protrude outside the conductive frame 70 in a plan view of the glass plate 10. This makes it easy to bring a conductive member, such as a conductor that electrically connects the ground potential to the ground conductor 75, into contact with the ground conductor 75. The shape of the ground conductor 75 is preferably a quadrangular shape such as a square, an approximately square, a rectangle, or an approximately rectangular shape for implementation, but is not limited to these, and other shapes such as a circle, an approximately circle, an ellipse, or an approximately ellipse may also be used.

[0057] 5 is a diagram illustrating two paths from the power supply part along the outer edge of the conductive frame to the ground conductor part. The length of the first path from the power supply part 80 along the outer edge 72 to the ground conductor part 75 is defined as D. CW The length of the second path from the feeding portion 80 along the outer edge 72 to the ground conductor portion 75 is defined as D CCW In this example, the first path is a clockwise path from the power supply unit 80, and the second path is a counterclockwise path from the power supply unit 80. In addition, the wavelength in the air of radio waves in the frequency band transmitted and received by the antenna ANT is denoted by λ, and the wavelength shortening rate determined by the glass plates 10 and 20 is denoted by k.

[0058] At this time, D CW and D CCW and M2 are approximately equal to an even multiple of (λ / 4×k), resonance can be obtained between the power feeding portion 80 and the ground conductor portion 75. This allows the position of the antinode of the standing wave generated along the conductive frame 70 to be adjusted to the position of the power feeding portion 80, thereby improving the antenna gain of the antenna ANT. In other words, when M1 and M2 are integers equal to or greater than 1, D CW = λ / 2×k×M1···Eq. aa D CCW = λ / 2×k×M2... Eq. bb Therefore, it is sufficient to satisfy at least one of the formulas aa and bb.

[0059] Therefore, when considering the manufacturing error of ±λ / 5×k for formula aa and formula bb, λ / 2×k×M1-λ / 5×k ≦ D CW≦ λ / 2×k×M1+λ / 5×k ...Equation 1a, λ / 2×k×M2-λ / 5×k ≦ D CCW ≦ λ / 2×k×M2+λ / 5×k ...Equation 1b, If at least one of the following conditions is satisfied, the antenna gain of the antenna ANT is improved. It is preferable to satisfy both conditions 1a and 1b.

[0060] The antenna gain of the antenna ANT is improved. λ / 2×k×M1-λ / 6×k ≦ D CW ≦ λ / 2×k×M1+λ / 6×k ...Equation 2a, λ / 2×k×M2-λ / 6×k ≦ D CCW ≦ λ / 2×k×M2+λ / 6×k ...Equation 2b, It is preferable that at least one of the following conditions is satisfied. It is more preferable that both conditions 2a and 2b are satisfied.

[0061] The antenna gain of the antenna ANT is improved. λ / 2×k×M1-λ / 7×k ≦ D CW ≦ λ / 2×k×M1+λ / 7×k ...Equation 3a, λ / 2×k×M2-λ / 7×k ≦ D CCW ≦ λ / 2×k×M2+λ / 7×k ...Equation 3b, It is more preferable that at least one of the following conditions is satisfied, and it is even more preferable that both of the following conditions 3a and 3b are satisfied.

[0062] Also, D CW is D CCW If it is different from (D CW ≠ D CCW If the condition is satisfied, the most resonant frequency is D CW and D CCW Since the frequencies are different, the antenna ANT can be made wider bandwidth.

[0063] Note that λ may be the wavelength in air of radio waves of some frequencies included in a predetermined frequency band transmitted and received by the antenna ANT. Preferably, it may be the wavelength in air of radio waves of all frequencies included in the predetermined frequency band. The same applies to λ in the equations described below.

[0064] Furthermore, it is preferable that the ground conductor 75 be directly connected to the earth potential in order to improve the antenna gain of the antenna ANT. For example, the ground conductor 75 is directly connected to the earth potential by being electrically connected to the vehicle body part 62, such as the window frame 63, through direct coupling. Note that the ground conductor 75 may also be electrically connected to the earth potential through capacitive coupling.

[0065] Furthermore, if the antenna device 201 includes coils 114 and 115 between the conductive layer 30 and the power source 111 that attenuate signals in the frequency band transmitted and received by the antenna ANT, leakage of the signals to the power source 111 is suppressed, thereby suppressing a decrease in the antenna gain of the antenna ANT. In the example shown in FIG. 3, the coil 114 is inserted in series between the conductive film 124 and the power source 111, and the coil 115 is inserted in series between the conductive film 125 and the power source 111. The inductance of the coils 114 and 115 depends on the area of ​​the light control film 120, but it is sufficient that it is 2.0 μH or less, and it may be 1.6 μH or less. If the inductance of the coils 114 and 115 is within any of the above ranges, signals in the VHF to UHF frequency bands can be attenuated.

[0066] FIG. 6 is a diagram illustrating two paths from the power supply unit 80 along the outer edge 72 of the conductive frame 70 to the connection unit 126. The portion of the conductive layer 30 that connects to the voltage control unit 110 is defined as the connection unit 126. For example, the "portion that connects to the voltage control unit 110" may also include the electrical length of the signal transmitted and received by the antenna ANT, taking into account the length of the power supply line (harness) from the conductive layer 30 to the coils 114 and 115. The clockwise path length from the power supply unit 80 along the outer edge 72 to the connection unit 126 is defined as L. CW , the counterclockwise path length from the feeding point 80 along the outer edge 72 to the connection point 126 is L CCWFurthermore, the wavelength in the air of radio waves in the frequency band transmitted and received by the antenna ANT is λ, the wavelength shortening rate determined by the glass plates 10 and 20 is k, and N1 and N2 are integers of 1 or more.

[0067] At this time, λ / 2×k×N1-λ / 5×k ≦ L CW ≦ λ / 2×k×N1+λ / 5×k ...Equation 4a, λ / 2×k×N2-λ / 5×k ≦ L CCW ≦ λ / 2×k×N2+λ / 5×k ...Equation 4b, If at least one of the above is satisfied, it is possible to suppress the influence of the feeder line connecting the connection unit 126 and the voltage control unit 110 on the antenna gain of the antenna ANT. It is preferable to satisfy both of the formulas 4a and 4b.

[0068] In order to suppress the influence of the power supply line connecting the connection unit 126 and the voltage control unit 110 on the antenna gain of the antenna ANT, λ / 2×k×N1-λ / 6×k ≦ L CW ≦ λ / 2×k×N1+λ / 6×k ...Equation 5a, λ / 2×k×N2-λ / 6×k ≦ L CCW ≦ λ / 2×k×N2+λ / 6×k ...Equation 5b, It is preferable that at least one of the following conditions is satisfied. It is more preferable that both conditions 5a and 5b are satisfied.

[0069] In order to suppress the influence of the power supply line connecting the connection unit 126 and the voltage control unit 110 on the antenna gain of the antenna ANT, λ / 2×k×N1-λ / 7×k ≦ L CW ≦ λ / 2×k×N1+λ / 7×k ...Equation 6a, λ / 2×k×N2-λ / 7×k ≦ L CCW ≦ λ / 2×k×N2+λ / 7×k ...Equation 6b, It is more preferable that at least one of the following conditions is satisfied, and it is even more preferable that both of the following conditions 6a and 6b are satisfied.

[0070] In FIG. 2, the window glass 101 may have a (frame-shaped) light-shielding portion (not shown) provided directly or indirectly on the main surface 11 of the glass plate 10. The light-shielding portion is, for example, a light-shielding film that blocks visible light. Specific examples of light-shielding films include ceramics such as black ceramic films. The light-shielding portion overlaps at least a portion of the conductive frame 70 in a plan view of the glass plate 10. This makes the overlapping portion less visible when the window glass 101 is viewed from the Z-axis direction (from the outside or inside of the vehicle), thereby improving the appearance of the window glass 101 and the design of the vehicle.

[0071] FIG. 7 is an exploded perspective view showing an example of the configuration of a vehicle antenna device according to the second embodiment. In the second embodiment, the description above is used to omit explanations of the configuration, actions, and effects that are similar to those of the first embodiment. The antenna device 202 according to the second embodiment includes a vehicle window glass 102. The window glass 102 differs from the window glass 101 according to the first embodiment in that a conductive layer 130 having a lower electrical resistance than the conductive layer 30 is provided between the interlayer 40A and the glass plate 10. The conductive layer 130 is an example of a second conductive layer.

[0072] 7 does not show the window frame 63. The window glass 102 may also be provided with a light blocking portion, similar to the first embodiment.

[0073] The conductive layer 130 is a planar conductor disposed directly or indirectly on the principal surface 11 of the glass plate 10. The conductive layer 130 may be a conductor in contact with the principal surface 11, or may be a conductor disposed on the principal surface 11 side via a transparent or translucent dielectric (not shown). The conductive layer 130 may be transparent or translucent. Specific examples of the conductive layer 130 include a metal film such as an Ag (silver) film, a metal oxide film such as an ITO (indium tin oxide) film, a resin film containing conductive particles, or a laminate of multiple types of films. The conductive layer 130 may be a resin film such as polyethylene terephthalate coated by vapor deposition or the like. The conductive layer 130 may be a film formed into a mesh shape by applying conductive ink or etching.

[0074] The conductive layer 130 may be a conductive film coated on the main surface 11 of the glass plate 10. A specific example of the conductive film is a low-emissivity film such as a low-E (Low Emissivity) film that exhibits low radiation performance.

[0075] Low emissivity refers to reducing heat transfer due to radiation. Low emissivity films such as Low-E films ensure thermal insulation by suppressing heat transfer due to radiation. The low emissivity film may be a general film. For example, the low emissivity film may be a laminated film including a transparent dielectric film, an infrared reflective film, and another transparent dielectric film in this order. Typical transparent dielectric films are metal oxides and metal nitrides. Typical metal oxides are zinc oxide and tin oxide. Typical infrared reflective films are metal films. Typical metal films are silver (Ag). Here, one or more infrared reflective films may be formed between the transparent dielectric films.

[0076] The conductive layer 130 is not limited to a low-emissivity film such as a low-E film, and may have other functions as long as it is a conductive layer. For example, the conductive layer 130 may have a function of preventing icing or fogging of the window glass 102 by generating heat when a voltage is applied.

[0077] The sheet resistance of the conductive layer 130 is preferably less than 5 [Ω / □], more preferably less than 4 [Ω / □], and even more preferably less than 3 [Ω / □], in order to improve the gain of the antenna ANT. The lower limit of the sheet resistance of the conductive layer 130 is not particularly limited, and is greater than 0 [Ω / □].

[0078] When the outer edge 131 of the conductive layer 130 is located outside the outer edge 31 of the conductive layer 30 in a plan view of the glass plate 10, it is possible to expand the area covered by the functions of the conductive layer 130, such as low emissivity. However, when the glass plate 10 is viewed in a plan view, the outer edge 131 of the conductive layer 130 may coincide with the outer edge 31 of the conductive layer 30 or may be located inside the outer edge 31.

[0079] When the conductive layer 130 overlaps the conductive frame 70 in a plan view of the glass plate 10, the conductive layer 130 and the conductive frame 70 are capacitively coupled, making it easier to ensure the gain of the antenna ANT. However, the conductive layer 130 does not have to overlap the conductive frame 70 in a plan view of the glass plate 10.

[0080] In the window glass 102 in FIG. 7 , the conductive layer 130 is shown as a conductor in contact with the main surface 11 of the glass plate 10. However, instead of being in contact with the main surface 11 of the glass plate 10, the conductive layer 130 may be arranged so as not to be in contact with the main surface 14 of the glass plate 20. More specifically, the conductive layer 130 may be arranged between the main surface 14 of the glass plate 20 and the conductive frame 70. In this case, too, it is sufficient that the electrical resistance of the conductive frame 70 is lower than the electrical resistance of the conductive layer 130. The above-mentioned low-emissivity film can be used as the conductive layer 130.

[0081] 7, the conductive layer 130 is shown as a conductor in contact with the main surface 11 of the glass plate 10. However, in addition to the conductive layer 130, another conductive layer (third conductive layer) (not shown) may be disposed directly or indirectly on the main surface 14 of the glass plate 20. In this case, too, it is sufficient that the electrical resistance of the conductive frame 70 is lower than the electrical resistance of the third conductive layer. An example of a combination is one in which the third conductive layer is a low-emissivity film and the conductive layer 130 is an infrared-reflecting film.

[0082] 8 is an exploded perspective view showing an example of the configuration of a vehicle antenna device according to the third embodiment. In the third embodiment, the description of the configuration, operation, and effects similar to those of the first or second embodiment will be omitted by citing the above description. The antenna device 203 according to the third embodiment includes a vehicle window glass 103. The window glass 103 differs from the window glass 101 according to the first embodiment in that it does not include a conductive frame 70 but includes a conductive layer 130. The window glass 103 may include a light-shielding portion, as in the first embodiment.

[0083] The window glass 103 is a laminated glass having, as its main components, a glass plate 10, a glass plate 20, a conductive layer 30, an interlayer film 40, a conductive layer 130, and a power supply part 180.

[0084] In the third embodiment, the conductive layer 130 is disposed between the interlayer 40A and the glass plate 10 and has a lower electrical resistance than the conductive layer 30. The sheet resistance of the conductive layer 130 is preferably less than 5 [Ω / □], more preferably less than 4 [Ω / □], and even more preferably less than 3 [Ω / □], in order to improve the gain of the antenna ANT. The lower limit of the sheet resistance of the conductive layer 130 is not particularly limited, and is greater than 0 [Ω / □].

[0085] In the third embodiment, the power supply unit 180 is electrically connected to a conductor region 132 of the conductive layer 130 that is located outside the conductive layer 30 in a plan view of the glass plate 10. In the example shown in Fig. 8, a dielectric such as the glass plate 20 is interposed between the power supply unit 180 and the conductor region 132, and therefore the power supply unit 180 is electrically connected to the conductor region 132 by capacitive coupling.

[0086] The form or position of the power supply unit 180 may be the same as the form or position of the power supply unit 80 of the first embodiment.

[0087] 8 , the interlayer 40A is interposed between the conductive layer 130 and the conductive layer 30. Therefore, a conductor region 132 of the conductive layer 130 that is located outside the conductive layer 30 in a planar view of the glass sheet 10 is electrically connected to the conductive layer 30 by capacitive coupling. Therefore, by attaching the window glass 103 to a conductive window frame 63, the conductive layer 30 and the conductive layer 130 can function as antenna conductors for the patch antenna, and the vehicle body 62 and the window frame 63 can function as grounds for the patch antenna. With the conductive layer 30 and the conductive layer 130 functioning as antenna conductors, a high-frequency current generated in the conductor region 132 of the conductive layer 130 that is located outside the conductive layer 30 in a planar view of the glass sheet 10 can be extracted from the power supply unit 180 that is electrically connected to the conductor region 132. Furthermore, since the conductive layer 130 (conductor region 132) has a lower electrical resistance than the conductive layer 30, high frequency current generated in the conductor region 132 flows more easily, thereby improving the antenna gain of a patch antenna that uses the conductive layer 30 and the conductive layer 130 as antenna conductors. An index for evaluating the level of the "electrical resistance" mentioned here is the sheet resistance value (unit: Ω / □).

[0088] Alternatively, by attaching the window glass 103 to a conductive window frame 63, the conductive layer 130 functions as part of a slot antenna that uses the gap between the conductor region 132 and the window frame 63 as a slot. Specifically, one example of a combination is one in which the conductive layer 30 is a light control film (a conductive film included in the light control film) and the conductive layer 130 is an infrared reflective film.

[0089] As described above, according to the third embodiment, the conductive layer 30 and the conductive layer 130 each function as part of a patch antenna that transmits and receives radio waves in a predetermined frequency band. Alternatively, the conductive layer 130 functions as part of a slot antenna that transmits and receives radio waves in a predetermined frequency band. Therefore, even if the conductive layer 30 has a relatively high electrical resistance, it is possible to provide an antenna device 203 that can transmit and receive radio waves in a predetermined frequency band with high gain.

[0090] Hereinafter, the antenna using the conductive layer 130 will be referred to as antenna ANT2. Antenna ANT2 operates using the power supply section 180 as a power supply point. Unless otherwise specified, antenna ANT2 has the same functions as the above-mentioned antenna ANT.

[0091] 8, the power supply unit 180 is located on the side of the glass plate 20 opposite the main surface 11 of the glass plate 10, and overlaps with at least a portion of the conductor region 132 in a plan view of the glass plate 10, and is therefore electrically connected to the conductor region 132 by capacitive coupling. In other words, the power supply unit 180 overlaps with at least a portion of a projection region 170 obtained by projecting the conductor region 132 onto the glass plate 20, and is therefore electrically connected to the conductor region 132 by capacitive coupling. In the example shown in FIG. 8, in a plan view of the glass plate 20, the inner edge 171 of the projection region 170 of the conductor region 132 coincides with the inner edge 133 of the conductor region 132 (the outer edge 31 of the conductive layer 30). Note that the interlayer film 40 is approximately 1 mm thick, and the glass plate 20 is approximately 2 mm thick, and therefore the power supply unit 180 is located at a distance (approximately 3 mm) that allows capacitive coupling with the conductor region 132.

[0092] 8, an outer edge 131 of the conductive layer 130 is located outside the outer edge 31 of the conductive layer 30 in a plan view of the glass plate 10, and the conductive region 132 is a frame-shaped region in which the conductive layer 130 does not overlap with the conductive layer 30 in a plan view of the glass plate 10. The conductive region 132 being such a frame-shaped region improves the antenna gain of the antenna ANT2.

[0093] 8, in order for the conductive region 132 to resonate at high frequencies, it is preferable that half the length (L / 2) of the perimeter L of the outer edge 131 of the conductive region 132 approximately coincides with "λ / 4×k×(2×N-1)." Here, λ is the wavelength in air of radio waves in the frequency band transmitted and received by the conductive region 132 (antenna ANT2), k is the wavelength shortening rate determined by the glass sheets 10 and 20, and N is an integer equal to or greater than 1. However, since the size of the window frame 63 differs depending on the vehicle model, half the length (L / 2) of the perimeter L of the conductive region 132 may not approximately coincide with "λ / 4×k×(2×N-1)."

[0094] To address such a situation, the window glass 103 according to the third embodiment may include a ground conductor 175 at a location away from the power supply unit 180, as shown in FIG. 8 . The ground conductor 175 is an example of a ground conductor that is electrically connected to the conductor region 132 and has a potential equivalent to the earth potential. The ground conductor 175 is, for example, a ground electrode that is electrically connected to the earth potential. By adjusting the position of the ground conductor 175 that is electrically connected to the earth potential (for example, the earth potential of the vehicle body 62 or the window frame 63), the position of the antinode of the standing wave generated along the conductor region 132 can be adjusted to the position of the ground conductor 175. This makes it possible to easily adjust the position of the antinode of the standing wave generated along the conductor region 132 to the position of the power supply unit 180, thereby improving the antenna gain of the antenna ANT2.

[0095] The ground conductor 175 may protrude outside the conductor region 132 in a plan view of the glass plate 10. This embodiment makes it easy to bring a conductive member, such as a conductor wire that electrically connects the ground potential to the ground conductor 175, into contact with the ground conductor 175. The shape of the ground conductor 175 is preferably a quadrangular shape, such as a square, an approximately square, a rectangle, or an approximately rectangular shape, for implementation purposes, but is not limited to these, and other shapes, such as a circle, an approximately circle, an ellipse, or an approximately ellipse, may also be used.

[0096] Here, in a plan view of the glass plate 10, the clockwise path length from the power supply part 180 along the outer edge 131 of the conductor region 132 to the ground conductor part 175 is defined as D. CW , the counterclockwise path length from the feeding part 180 along the outer edge 131 to the ground conductor part 175 is D CCW Furthermore, the wavelength in the air of the radio waves in the frequency band transmitted and received by the antenna ANT2 is λ, and the wavelength shortening rate determined by the glass plates 10 and 20 is k.

[0097] In this case, the power supply unit 180 is located on the opposite side of the glass plate 20 from the main surface 11 of the glass plate 10, and overlaps with at least a part of the conductor region 132 in a plan view of the glass plate 10, and is therefore electrically connected to the conductor region 132 by capacitive coupling. CW or D CCW When the length of the power supply 180 coincides with an odd multiple of λ / 4×k (see the above equations aa and bb), resonance is obtained between the power supply 180 and the ground conductor 175.

[0098] Therefore, when M1 and M2 are integers of 1 or more, taking into consideration manufacturing errors of ±λ / 5×k, λ / 4×k×(2×M1-1)-λ / 5×k ≦ D CW ≦ λ / 4×k×(2×M1-1)+λ / 5×k ...Equation 7a, λ / 4×k×(2×M2-1)-λ / 5×k ≦ D CCW ≦ λ / 4×k×(2×M2-1)+λ / 5×k ...Equation 7b, If at least one of the following conditions is satisfied, the antenna gain of the antenna ANT2 is improved. It is preferable to satisfy both of the conditions 7a and 7b.

[0099] The antenna gain of antenna ANT2 is improved. λ / 4×k×(2×M1-1)-λ / 6×k ≦ D CW ≦ λ / 4×k×(2×M1-1)+λ / 6×k ...Equation 8a, λ / 4×k×(2×M2-1)-λ / 6×k ≦ D CCW ≦ λ / 4×k×(2×M2-1)+λ / 6×k ...Equation 8b, It is preferable to satisfy at least one of the following conditions: It is more preferable to satisfy both conditions 8a and 8b.

[0100] The antenna gain of antenna ANT2 is improved. λ / 4×k×(2×M1-1)-λ / 7×k ≦ D CW≦ λ / 4×k×(2×M1-1)+λ / 7×k ...Equation 9a, λ / 4×k×(2×M2-1)-λ / 7×k ≦ D CCW ≦ λ / 4×k×(2×M2-1)+λ / 7×k ...Equation 9b, It is more preferable that at least one of the following conditions is satisfied, and it is even more preferable that both of the following conditions 9a and 9b are satisfied.

[0101] Also, D CW is D CCW If it is different from (D CW ≠ D CCW holds), the most resonant frequency is D CW and D CCW Since the frequencies are different, the antenna ANT2 can be made wider bandwidth.

[0102] 6, the portion of the conductive layer 30 that is connected to the voltage control unit 110 is referred to as a connection unit 126. In a plan view of the glass plate 10, the clockwise path length from the power supply unit 180 along the outer edge 131 of the conductive region 132 to the connection unit 126 is referred to as L. CW , the length of the path from the feeding point 180 along the outer edge 131 to the connecting point 126 in the counterclockwise direction is L CCW Furthermore, the wavelength in the air of radio waves in the frequency band transmitted and received by the antenna ANT2 is λ, the wavelength shortening rate determined by the glass plates 10 and 20 is k, and N1 and N2 are integers of 1 or more.

[0103] In this case, similarly to the first embodiment, satisfying at least one of the above formulas 4a and 4b can suppress the influence of the feeder line connecting the connection unit 126 and the voltage control unit 110 on the antenna gain of the antenna ANT2. It is preferable to satisfy at least one of the above formulas 5a and 5b, and it is more preferable to satisfy at least one of the above formulas 6a and 6b.

[0104] 8, when the frame-shaped conductor region 132 has a closed loop shape, high frequency current flows more easily through the conductor region 132, improving the antenna gain of the antenna ANT2. However, a notch may be formed in part of the conductor region 132. The shape of the conductor region 132 is not limited to a substantially rectangular shape, and may be another polygonal shape such as a substantially triangular shape.

[0105] Furthermore, similarly to the first embodiment, when the power supply unit 180 is located near a corner of the frame-shaped conductive region 132 in a plan view of the glass plate 10, the antenna gain for both horizontally polarized waves and vertically polarized waves is improved. That is, when the power supply unit 180 is located near a corner of the frame-shaped conductive region 132, the antenna gain for both horizontally polarized waves and vertically polarized waves is improved. In other words, when the glass plate 10 is viewed in a plan view, the power supply unit 180 is located at a position that is within the range of the length L of the first side of the frame-shaped conductive region 132. X or from the corner of the frame-shaped conductive region 132 to the length L of the second side of the conductive region 132 Y It is preferable that the position is within one-third of the

[0106] Next, the results of a simulation of the antenna characteristics of the vehicle antenna device of each embodiment will be described.

[0107] 9 is a plan view of a simulation model of a vehicle antenna device according to the present disclosure. The conditions of the simulation model, such as the dimensions of each part, are as follows: Window frame 63: 2000mm x 2000mm ground plane Opening of window frame 63: 460mm (length) x 600mm (width) Outer edge of conductive frame 70: length 450 [mm] x width 590 [mm] Inner edge of conductive frame 70: length 430 [mm] x width 570 [mm] External dimensions of light control film 120: 450mm (length) x 590mm (width) Thickness of window frame 63: 0.1 mm Thickness of each of the glass plates 10 and 20: 2.1 mm Total thickness of intermediate films 40A and 40B: 0.8 mm Each thickness of the resin substrates 121 and 122: 0.1 mm Thickness of the dimming layer 123: 0.2 [mm] Sheet resistance of conductive layer 30 (conductive films 124, 125): 15 [Ω / □] Sheet resistance of conductive frame 70: 0.02 [Ω / □] Wavelength reduction rate k: 0.67 It was decided.

[0108] FIG. 10 shows the clockwise path length D from the power supply part 80 along the outer edge 72 of the conductive frame 70 to the ground conductor part 75 in the vehicle antenna device of the first embodiment (see FIGS. 1 and 2). CW 10 is a diagram showing an example of a simulation result of the reflection coefficient S11 with respect to the path length D at each frequency (170 MHz, 205 MHz, 240 MHz) included in the DAB Band III band. CW is the normalized value.

[0109] According to Fig. 10, when M1 = 1 and 2, the path length D that satisfies Equation 1a is CW In this case, the reflection coefficient S11 seen from the power supply 80 becomes low at one of the frequencies, and the antenna ANT resonates.

[0110] FIG. 11 shows the counterclockwise path length D from the power supply part 80 along the outer edge 72 of the conductive frame 70 to the ground conductor part 75 in the vehicle antenna device of the first embodiment (see FIGS. 1 and 2). CCW 11 is a diagram showing an example of a simulation result of the reflection coefficient S11 for the path length D at each frequency (170 MHz, 205 MHz, 240 MHz) included in the DAB Band III band. CCW is the normalized value.

[0111] According to Fig. 11, when M2 = 2 and 3, the path length D that satisfies Equation 1b is CCW In this case, the reflection coefficient S11 seen from the power supply 80 becomes low at one of the frequencies, and the antenna ANT resonates.

[0112] [Table 1] Table 1 shows an example of the simulation results of the average antenna gain when the antenna device 201 (see FIG. 2) of the first embodiment, which satisfies the formulas 1a and 1b, is applied to a side window. As shown in Table 1, an antenna gain suitable for receiving radio waves in the DAB Band III band was obtained.

[0113] [Table 2] Table 2 shows an example of the simulation results of the average antenna gain when the antenna device 202 (see FIG. 7) of the second embodiment, which satisfies the formulas 1a and 1b, is applied to a side window. As shown in Table 2, an antenna gain suitable for receiving radio waves in the DAB Band III band was obtained. In particular, the antenna gain for vertically polarized waves was improved compared to the antenna device 201 of the first embodiment (Table 1).

[0114] In addition, when measuring Table 2, the conditions such as the dimensions of each part of the simulation model are as follows: External dimensions of the conductive layer 130: 450 mm long x 590 mm wide Sheet resistance of conductive layer 130: 0.02 [Ω / □] It was decided.

[0115] FIG. 12 shows the clockwise path length D from the power supply portion 180 to the ground conductor portion 175 along the outer edge 131 of the conductor region 132 in a plan view of the glass plate 10 in the vehicle antenna device of the third embodiment (see FIG. 8). CW 12 is a graph showing an example of a simulation result of the reflection coefficient S11 for a wavelength of 205 MHz, which is included in the DAB Band III band, and a path length D CW is the normalized value.

[0116] According to Figure 12, when M1 = 3, the path length D that satisfies Equation 7a is CW In this case, the reflection coefficient S11 seen from the power supply section 180 becomes low, and the antenna ANT2 resonates.

[0117] FIG. 13 shows the path length D in the counterclockwise direction from the power supply portion 180 to the ground conductor portion 175 along the outer edge 131 of the conductor region 132 in a plan view of the glass plate 10 in the vehicle antenna device of the third embodiment (see FIG. 8). CCW 13 is a graph showing an example of a simulation result of the reflection coefficient S11 for a wavelength of 205 MHz included in the DAB Band III band. CCW is the normalized value.

[0118] According to Figure 13, when M2 = 4, the path length D that satisfies Equation 7b is CCW In this case, the reflection coefficient S11 seen from the power supply section 180 becomes low, and the antenna ANT2 resonates.

[0119] [Table 3] Table 3 shows an example of the simulation results of the average antenna gain when the antenna device 203 (see FIG. 8) of the third embodiment, which satisfies the formulas 7a and 7b, is applied to a side window. As shown in Table 3, an antenna gain suitable for receiving radio waves in the DAB Band III band was obtained.

[0120] In addition, when measuring Figures 12 and 13 and Table 3, the conditions for the dimensions of each part of the simulation model were as follows: External dimensions of the conductive layer 130: 450 mm long x 590 mm wide Sheet resistance of conductive layer 130: 0.02 [Ω / □] Wavelength reduction rate k: 0.5 It was decided.

[0121] Although the embodiments of the present disclosure have been described above, the technology of the present disclosure is not limited to the above-described embodiments. Various modifications and improvements are possible, such as combinations with or substitutions for part or all of other embodiments.

[0122] For example, the first dielectric plate or the second dielectric plate is not limited to a glass plate, but may be another dielectric plate such as a resin plate. The entire contents of the specification, claims, drawings and abstract of Japanese Patent Application No. 2021-135879, filed on August 23, 2021, are hereby incorporated by reference as part of the disclosure of the specification of the present invention. [Explanation of symbols]

[0123] 10 Glass Plate 11, 12, 14, 15 main surfaces 13a, 13b, 13c, 13d outer edge 20 Glass Plate 30 Conductive layer 31 outer edge 40,40A,40B Intermediate film 60 vehicles 61 slots 62 Body 63 Window Frame 70 Conductive Frame 71 Common-law marriage 72 outer edge 73a,73b,73c,73d corner 75 Ground conductor 80 Power supply unit 90 Power line 91 Signal line 92 Grounding part 101, 102, 103 Window glass 110 Voltage control section 111 Power supply 114,115 Coil 120 Light Control Film 121,122 Resin substrate 123 Photochromic Layer 124,125 Conductive film 126 Connection 130 Conductive layer 131 outer edge 132 Conductor Area 133 Common-law marriage 170 Projection area 171 Common-law marriage 175 Grounding conductor 180 Power supply unit 201, 202, 203 Vehicle antenna device

Claims

1. a first dielectric plate having a main surface; a second dielectric plate disposed directly or indirectly on the main surface of the first dielectric plate; a first conductive layer disposed between a first intermediate film and a second intermediate film between the first dielectric plate and the second dielectric plate; a conductive frame disposed between the first dielectric plate and the first intermediate film, between the second dielectric plate and the second intermediate film, or on the opposite side of the second dielectric plate from the main surface, the conductive frame having an inner edge that follows an outer edge of the first conductive layer in a plan view of the first dielectric plate; a power supply portion electrically connected to the conductive frame; a voltage control unit electrically connected to the first conductive layer, the voltage control unit including a power source, and controlling a voltage applied to the first conductive layer; Equipped with The conductive frame has a lower electrical resistance than the first conductive layer and functions as part of an antenna that transmits and receives radio waves in a predetermined frequency band.

2. 2. The vehicle antenna device according to claim 1, further comprising a ground conductor portion electrically connected to the conductive frame and having a potential equivalent to a ground.

3. the conductive frame is disposed on the opposite side of the second dielectric plate from the main surface, 3. The vehicle antenna device according to claim 2, wherein at least one of the following expressions is satisfied: λ / 2×k×M １ -λ / 5×k ≦ D ＣＷ ≦ λ / 2×k×M １ +λ / 5×k, λ / 2×k×M ２ -λ / 5×k ≦ D ＣＣＷ ≦ λ / 2×k×M ２ +λ / 5×k, Here, D ＣＷ is the clockwise path length from the power supply part along the outer edge of the conductive frame to the ground conductor part, and D ＣＣＷ is the counterclockwise path length from the feeding part along the outer edge of the conductive frame to the ground conductor part, λ is the wavelength in air of the frequency band, k is the wavelength shortening rate determined by the first dielectric plate and the second dielectric plate, and M １ and M ２ is an integer of 1 or greater.

4. The above D ＣＷ and the above D ＣＣＷ 4. The vehicle antenna device according to claim 3, wherein the following formula is satisfied: D ＣＷ ≠ D ＣＣＷ

5. a portion of the first conductive layer connected to the voltage control unit is a connection portion; 2. The vehicle antenna device according to claim 1, wherein at least one of the following expressions is satisfied: λ / 2×k×N １ -λ / 5×k ≦ L ＣＷ ≦ λ / 2×k×N １ +λ / 5×k, λ / 2×k×N ２ -λ / 5×k ≦ L ＣＣＷ ≦ λ / 2×k×N ２ +λ / 5×k, Here, L ＣＷ is the clockwise path length from the feeding part along the outer edge of the conductive frame to the connection part, and L ＣＣＷ is the counterclockwise path length from the feeding part along the outer edge of the conductive frame to the connecting part, λ is the wavelength of the frequency band, k is the wavelength shortening rate determined by the first dielectric plate and the second dielectric plate, and N １ and N ２ is an integer of 1 or greater.

6. The vehicle antenna device according to claim 1 , wherein the conductive frame has a closed loop shape.

7. the conductive frame includes a corner, a first side extending from the corner in a first direction, and a second side extending from the corner in a second direction; 2. The vehicle antenna device according to claim 1, wherein the power supply portion is disposed at a position within a range of 1 / 3 of the length of the first side from the corner portion or within a range of 1 / 3 of the length of the second side from the corner portion.

8. The vehicle antenna device according to claim 1 , further comprising: a second conductive layer having a lower electrical resistance than the first conductive layer, the second conductive layer being disposed between the first intermediate film and the first dielectric plate.

9. The vehicle antenna device according to claim 8 , wherein, in a plan view of the first dielectric plate, an outer edge of the second conductive layer is located outside an outer edge of the first conductive layer.

10. The vehicle antenna device according to claim 8 , wherein the second conductive layer overlaps the conductive frame in a plan view of the first dielectric plate.

11. a first dielectric plate having a main surface; a second dielectric plate disposed directly or indirectly on the main surface of the first dielectric plate; a first conductive layer disposed between a first intermediate film and a second intermediate film between the first dielectric plate and the second dielectric plate; a second conductive layer disposed between the first intermediate film and the first dielectric plate and having a lower electrical resistance than the first conductive layer; a power supply portion electrically connected to a conductor region of the second conductive layer that is located outside the first conductive layer in a plan view of the first dielectric plate; a voltage control unit electrically connected to the first conductive layer, the voltage control unit including a power source, and controlling a voltage applied to the first conductive layer; Equipped with The second conductive layer functions as a part of an antenna that transmits and receives radio waves in a predetermined frequency band.

12. The vehicle antenna device according to claim 11, wherein the power supply portion is located on an opposite side of the second dielectric plate from the main surface.

13. The vehicle antenna device according to claim 11, wherein the power supply portion overlaps at least a part of the conductor region in a plan view of the first dielectric plate.

14. an outer edge of the second conductive layer is located outside an outer edge of the first conductive layer in a plan view of the first dielectric plate; The vehicle antenna device according to claim 11, wherein the conductor region is a frame-shaped region in which the second conductive layer does not overlap the first conductive layer in a plan view of the first dielectric plate.

15. The vehicle antenna device according to claim 14, further comprising a ground conductor portion electrically connected to the frame-shaped region and having a potential equivalent to a ground.

16. the power supply portion is located on the opposite side of the second dielectric plate from the main surface, and overlaps with at least a portion of the conductor region in a plan view of the first dielectric plate; 16. The vehicle antenna device according to claim 15, wherein at least one of the following expressions is satisfied: λ / 4×k×(2×M) １ -1)-λ / 5×k ≦ D ＣＷ ≦ λ / 4×k×(2×M) １ -1) +λ / 5×k, λ / 4×k×(2×M) ２ -1)-λ / 5×k ≦ D ＣＣＷ ≦ λ / 4×k×(2×M) ２ -1) +λ / 5×k, Here, D ＣＷ is the clockwise path length from the power supply portion along the outer edge of the frame-shaped region to the ground conductor portion in a plan view of the first dielectric plate, and D ＣＣＷ is the counterclockwise path length from the power supply part along the outer edge of the frame-shaped region to the ground conductor part in a plan view of the first dielectric plate, λ is the wavelength of the frequency band, k is the wavelength shortening rate determined by the first dielectric plate and the second dielectric plate, and M １ and M ２ is an integer of 1 or greater.

17. The above D ＣＷ and the above D ＣＣＷ 17. The vehicle antenna device according to claim 16, wherein the following formula is satisfied: D ＣＷ ≠ D ＣＣＷ

18. the power supply portion is located on the opposite side of the second dielectric plate from the main surface, and overlaps with at least a portion of the conductor region in a plan view of the first dielectric plate; a portion of the first conductive layer connected to the voltage control unit is a connection portion; 15. The vehicle antenna device according to claim 14, wherein at least one of the following expressions is satisfied: λ / 2×k×N １ -λ / 5×k ≦ L ＣＷ ≦ λ / 2×k×N １ +λ / 5×k, λ / 2×k×N ２ -λ / 5×k ≦ L ＣＣＷ ≦ λ / 2×k×N ２ +λ / 5×k, Here, L ＣＷ is a clockwise path length from the feeding portion along the outer edge of the frame-shaped region to the connecting portion in a plan view of the first dielectric plate, L ＣＣＷ is the counterclockwise path length from the feeding point along the outer edge of the frame-shaped region to the connecting point in a plan view of the first dielectric plate, λ is the wavelength of the frequency band, k is the wavelength shortening rate determined by the first dielectric plate and the second dielectric plate, and N １ and N ２ is an integer of 1 or greater.

19. The vehicle antenna device according to claim 14, wherein the frame-shaped region has a closed loop shape.

20. the frame-shaped region includes a corner, a first side extending from the corner in a first direction, and a second side extending from the corner in a second direction; 15. The vehicle antenna device according to claim 14, wherein, in a plan view of the first dielectric plate, the power supply portion is arranged at a position within a range of 1 / 3 of the length of the first side from the corner portion, or at a position within a range of 1 / 3 of the length of the second side from the corner portion.

21. The vehicle antenna device according to claim 8 , wherein the second conductive layer has a sheet resistance of less than 5 Ω / □.

22. The vehicle antenna device according to claim 8 , wherein the second conductive layer includes an infrared reflective film.

23. The vehicle antenna device according to claim 1 , further comprising a coil between the first conductive layer and the power source, the coil attenuating signals in a frequency band transmitted and received by the antenna.

24. The vehicle antenna device according to claim 1 , wherein the first conductive layer has a sheet resistance of 5 Ω / □ or more and 300 Ω / □ or less.

25. The vehicle antenna device according to claim 1 , wherein the first conductive layer is a conductor included in a light control film.

26. The vehicle antenna device according to claim 1 , wherein the frequency band is a VHF band.

27. The vehicle antenna device according to claim 1 , wherein the frequency band is a UHF band.

28. The vehicle antenna device according to claim 1 , wherein the first dielectric plate is a first glass plate, and the second dielectric plate is a second glass plate.

29. 29. The vehicle antenna device according to claim 28, wherein the first glass plate and the second glass plate are for side windows.

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