Vehicle antenna device and vehicle-mounted system

Abstract

The present invention suppresses noise mixed into an antenna provided to a glass plate.　Provided is a vehicle antenna device which comprises: a glass plate for a vehicle; a first antenna which is provided to the glass plate and through which a radio wave in a first frequency band can be received or transmitted; and an electrical circuit that attenuates a signal in a second frequency band including a frequency band higher than the first frequency band. The first antenna has a first power supply unit electrically connected to a signal line of a transmission line path and a first element connected to the first power supply unit. The electrical circuit is provided between the first power supply unit or a vicinity portion of the first power supply unit and an earth and / or between the first power supply unit and the signal line.

Description

[Technical Field]

[0001] The present disclosure relates to a vehicle antenna device and an in-vehicle system. [Background technology]

[0002] In recent years, there has been a trend toward installing various electronic devices, such as visible light cameras, radars, and sensors, on or near vehicle window glass. Furthermore, vehicle window glass, such as windshields, may have antenna patterns for receiving broadcast waves. However, placing the electronic device close to the antenna pattern so as not to unnecessarily obstruct the view through the window glass can cause problems such as unstable antenna operation and reduced antenna gain.

[0003] Therefore, a technique is known in which a noise removal pattern is provided between an electronic device and an antenna to absorb noise traveling from the electronic device to the antenna and reduce noise arriving at the antenna (see, for example, Patent Document 1). Also known is a technique in which a cancellation element is provided between the electronic device and the antenna to suppress noise arriving from the electronic device to the antenna (see, for example, Patent Document 2). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2019 / 181623 [Patent Document 2] International Publication No. 2018 / 079415 Summary of the Invention [Problem to be solved by the invention]

[0005] In some cases, an antenna configured to receive radio waves in a predetermined frequency band is provided on a glass plate for a vehicle, as in the prior art. However, there is a risk that electromagnetic waves (noise) in a second frequency band that includes a frequency band higher than the predetermined first frequency band may be mixed into the antenna.

[0006] The present disclosure provides a vehicle antenna device capable of suppressing signals (noise) that are mixed into an antenna mounted on a glass plate as electromagnetic waves of a frequency higher than the frequency transmitted and received by the antenna, and an in-vehicle system equipped with the vehicle antenna device. [Means for solving the problem]

[0007] In one aspect of the present disclosure, Glass plates for vehicles; a first antenna provided on the glass plate and capable of receiving or transmitting radio waves in a first frequency band; an electric circuit that attenuates signals in a second frequency band that includes a frequency band higher than the first frequency band; the first antenna has a first feeding portion electrically connected to a signal line of a transmission line and a first element connected to the first feeding portion; A vehicle antenna device is provided in which the electric circuit is provided at least one of between the first power supply unit or a portion near the first power supply unit and an earth unit, and between the first power supply unit and the signal line.

[0008] In another aspect of the present disclosure, the vehicle antenna device; an electronic device located away from the first antenna, An in-vehicle system is provided, wherein the electronic device emits electromagnetic waves in the second frequency band. [Effects of the Invention]

[0009] According to the present disclosure, it is possible to provide a vehicle antenna device capable of suppressing noise that has entered an antenna provided on a glass plate, and an in-vehicle system including the vehicle antenna device. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a diagram schematically illustrating a configuration example of a vehicle antenna device according to an embodiment in a plan view of a window glass; [Figure 2] 2A and 2B are diagrams illustrating a first configuration example and a second configuration example of an electric circuit. [Figure 3] FIG. 10 is a plan view showing a third configuration example of the electric circuit; [Figure 4] FIG. 10 is a cross-sectional view showing a third configuration example of the electric circuit. [Figure 5] FIG. 10 is a plan view showing a fourth configuration example of the electric circuit; [Figure 6] FIG. 10 is a cross-sectional view showing a fourth configuration example of the electric circuit. [Figure 7] FIG. 10 is a cross-sectional view showing a fifth configuration example of an electric circuit. [Figure 8] FIG. 10 is a cross-sectional view showing a sixth configuration example of an electric circuit. [Figure 9] FIG. 10 is a cross-sectional view showing a seventh configuration example of an electric circuit. [Figure 10] FIG. 13 is a plan view showing an eighth configuration example of the electric circuit. [Figure 11] FIG. 13 is a plan view showing a ninth configuration example of the electric circuit. [Figure 12] FIG. 19 is a perspective view showing a tenth configuration example of an electric circuit. [Figure 13] FIG. 19 is a perspective view showing an eleventh configuration example of an electric circuit. [Figure 14] FIG. 14 is an exploded perspective view showing a specific structural example of the electric circuit according to the eleventh configuration example shown in FIG. [Figure 15] 1 is a diagram showing a basic configuration of a vehicle antenna device when antenna characteristics are actually measured; [Figure 16] FIG. 10 is a diagram showing a first example of the results of actually measuring the transmission coefficient S21 of the vehicle antenna device. [Figure 17] FIG. 10 is a diagram showing a second example of the results of actually measuring the transmission coefficient S21 of the vehicle antenna device. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, embodiments will be described with reference to the drawings. Note that for ease of understanding, the scale of each part in the drawings may differ from the actual scale. Directions such as parallel, right-angled, orthogonal, horizontal, vertical, up-down, left-right, and so on are permissible to the extent that they do not impair the functions and effects of the embodiments. The X-axis, Y-axis, and Z-axis directions represent directions parallel to the X-axis, Y-axis, and Z-axis, respectively. The X-axis, Y-axis, and Z-axis directions are mutually orthogonal. The XY plane, YZ plane, and ZX plane represent 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.

[0012] Examples of the vehicle window glass in this embodiment include a rear glass attached to the rear of the vehicle, a windshield attached to the front of the vehicle, a side glass attached to the side of the vehicle, a roof glass attached to the ceiling of the vehicle, etc. The vehicle window glass is not limited to these examples.

[0013] FIG. 1 is a diagram illustrating a schematic configuration example of a vehicle antenna device according to an embodiment in a plan view of a window glass. The antenna device 100 illustrated in FIG. 1 is an example of a vehicle antenna device mounted on a vehicle. The antenna device 100 includes an antenna 10 and an electronic device 20 located in close proximity to the antenna 10. The antenna 10 is an example of a first antenna capable of receiving radio waves in a first frequency band. The electronic device 20 is a device that emits radio waves in a second frequency band that includes a frequency band higher than the first frequency band, and specific examples of such a device include an antenna, a visible light camera, a radar, and sensors. In particular, the electronic device 20 is an example of a second antenna capable of transmitting radio waves in the second frequency band. Hereinafter, unless otherwise specified, the electronic device 20 will be described as the antenna 20.

[0014] The antenna 10 may be an antenna capable of transmitting and receiving radio waves in a first frequency band. The antenna 20 may be an antenna capable of transmitting and receiving radio waves in a second frequency band. "Transmitting and receiving" refers to performing both transmission and reception. "Receiving (or transmitting and receiving)" radio waves in the first frequency band may mean receiving (or transmitting and receiving) radio waves in a portion of the first frequency band, or receiving (or transmitting and receiving) radio waves in the entire first frequency band. "Transmitting (or transmitting and receiving)" radio waves in the second frequency band may mean transmitting (or transmitting and receiving) radio waves in a portion of the second frequency band, or transmitting (or transmitting and receiving) radio waves in the entire second frequency band.

[0015] The first frequency band is, for example, the UHF (Ultra High Frequency) band with a frequency of 300 MHz to 3 GHz, the VHF (Very High Frequency) band with a frequency of 30 MHz to 300 MHz, or a band spanning both. Specific examples of frequency bands included in the UHF band include the band of terrestrial digital television broadcast waves (e.g., 470 MHz to 710 MHz). Specific examples of frequency bands included in the VHF band include the band of FM broadcast waves (e.g., 76 MHz to 108 MHz) and the band of DAB Band III (e.g., 174 MHz to 240 MHz).

[0016] The second frequency band is, for example, a high frequency band (e.g., 0.3 GHz to 300 GHz) such as microwaves or millimeter waves. Specific examples of frequency bands included in the second frequency band include sub6 (e.g., 3.6 GHz to 6 GHz), the 2.4 GHz band, the 5.2 GHz band, the 5.3 GHz band, the 5.6 GHz band, the 5.8 GHz band, and the 5.9 GHz band.

[0017] The low frequency band of the second frequency band may or may not overlap with the high frequency band of the first frequency band. For example, the second frequency band may be 617 MHz or higher and the first frequency band may be 710 MHz or lower.

[0018] The antenna 20 is applicable to a V2X communication system, a fifth-generation mobile communication system, a sixth-generation mobile communication system, an in-vehicle radar system, etc. Systems to which the antenna 20 is applicable are not limited to these. Specific examples of a V2X communication system include a vehicle-to-vehicle communication system and a road-to-vehicle communication system (e.g., an ETC system).

[0019] The antenna 10 is provided on the window glass 1. The antenna 20 is provided on or near the window glass 1. "Near the window glass 1" refers to, for example, the interior of the vehicle, located more than 0 mm to 100 mm away from the glass surface of the window glass 1. In this case, the radiating surface of the antenna 20 may be disposed so as to face the glass surface via a dielectric. Furthermore, "near the window glass 1" refers not only to the interior of the vehicle, but also to the exterior of the vehicle, located more than 0 mm to 100 mm away from the glass surface of the window glass 1. In this case, the antenna 20 may be built into a roof spoiler located outside the vehicle, near the rear glass, with the radiating surface of the antenna located more than 0 mm to 100 mm away from the rear glass surface, and the antenna 10 may be provided on the rear glass surface. The antenna provided near the window glass 1 may be mounted on a rear device (e.g., a high-mounted stop lamp, a rearview camera, etc.) located near the rear glass, or may be disposed near the rear device. Of course, the window glass 1 is not limited to a rear window, and may be other window glass such as a windshield, etc. Fig. 1 illustrates an example in which both the antenna 10 and the antenna 20 are provided on the surface of the window glass 1.

[0020] The antenna may be provided on the window glass by being provided on the surface of the window glass or by being enclosed in the window glass. Specific examples of locations near the window glass include locations on the vehicle that are distant from the window glass, such as the roof, console, pillar, garnish, and mirror. The antenna may be provided near the window glass 1 by being attached to a member attached to the window glass or near the window glass.

[0021] At least one of antenna 10 and antenna 20 may be disposed on a light-shielding film 5 formed on the glass surface at the periphery of window glass 1. Part or all of antenna 10 may be disposed on light-shielding film 5, and part or all of antenna 20 may be disposed on light-shielding film 5. Specific examples of light-shielding film 5 include ceramics such as black enamel film. When window glass 1 is viewed from outside the vehicle, the portion of light-shielding film 5 that is located closer to the glass edge than inner edge 5a is less visible from outside the vehicle, improving the design of the window glass.

[0022] Furthermore, at least one of antenna 10 and antenna 20 is not limited to being provided along the upper glass edge 1a of window glass 1 (in other words, the upper edge of a window frame (not shown) to which window glass 1 is attached) as shown in Fig. 1. For example, at least one of antenna 10 and antenna 20 may be provided along the lower glass edge 1b of window glass 1 (the lower edge of the window frame), the left glass edge 1c of window glass 1 (the left edge of the window frame), or the right glass edge 1d of window glass 1 (the right edge of the window frame).

[0023] Antenna 10 has a power supply unit 16 electrically connected to a signal line (not shown) of a transmission line such as a coaxial cable, and an antenna element 13 electrically connected to power supply unit 16. Power supply unit 16 is an example of a first power supply unit. Power supply unit 16 is a feeding point located between the signal line of the transmission line and antenna element 13, and is, for example, a feeding electrode. Antenna element 13 is an example of a first element. Antenna 10 may be a monopole antenna that uses an external ground such as the metal body of a vehicle, or may be a dipole antenna that further has a grounding electrode (not shown).

[0024] The antenna device 100 includes an electric circuit 30. The electric circuit 30 has a structure that attenuates signals in a second frequency band that includes a frequency band higher than the first frequency band. The electric circuit 30 is a circuit that passes signals in the first frequency band with almost no attenuation and attenuates signals in the second frequency band more than signals in the first frequency band. The electric circuit 30 functions as a low-pass filter.

[0025] The electric circuit 30 is provided at least one of between the power feed 16 or the vicinity of the power feed 16 and the ground, and between the power feed 16 and the signal line of the transmission line. By providing the electric circuit 30, which attenuates signals in the second frequency band, in such a location, isolation between the antenna 10 and the antenna 20 is ensured in the second frequency band. This makes it possible to suppress disturbance of the desired signal to be transmitted and received by the antenna 10 due to unwanted signals (noise) containing components in the second frequency band that are mixed into the antenna 10, even if the antennas 10 and 20 are close to each other. Note that "the vicinity of the power feed 16" refers to, for example, a portion of the antenna element 13 connected to the power feed 16 that is close to the power feed 16. In other words, the electric circuit 30 may be provided between the portion of the antenna element 13 that is close to the power feed 16 and the ground.

[0026] For example, signals containing components of the second frequency band that are mixed into antenna 10 from antenna 20 are suppressed by electrical circuit 30, thereby reducing signals of unnecessary frequency bands that propagate to a receiving device connected to power supply unit 16 via a signal line of the transmission line, thereby improving reception quality.

[0027] Furthermore, for example, when antenna 10 is an antenna capable of transmitting radio waves in a first frequency band, unwanted signals containing components in a second frequency band radiated from antenna 10 are suppressed by electric circuit 30. This suppresses interference of signals containing components in the second frequency band from antenna 10 to antenna 20. Therefore, when a receiving device is connected to the power feed portion of antenna 20 via a signal line of a transmission line, signals in the unwanted frequency band propagating to the receiving device are reduced, improving reception quality.

[0028] When the distance D between the antennas 10 and 20 is 100 mm or less, the antenna 10 is susceptible to unwanted signals containing components of the second frequency band. However, the antenna 10 including the electric circuit 30 can suppress these unwanted signals. Note that when the distance D exceeds 100 mm, the antennas 10 and 20 are too far apart, making it difficult to secure space for arranging the antennas 10 and 20, potentially reducing layout flexibility. Furthermore, when the distance D between the antennas 10 and 20 exceeds 100 mm, a certain level of isolation can be easily ensured in a predetermined frequency band, even without the electric circuit 30. Furthermore, when the distance D between the antennas 10 and 20 is 70 mm or less, the antenna 10 can effectively suppress unwanted signals containing components of the second frequency band. When the distance D is 50 mm or less, the antenna 10 can more effectively suppress unwanted signals containing components of the second frequency band. When the distance D is 45 mm or less, the antenna 10 can even more effectively suppress unwanted signals containing components of the second frequency band. When the distance D is 40 mm or less, the antenna 10 can particularly effectively suppress unwanted signals including components of the second frequency band. The lower limit of the distance D may be any distance between the antennas 10 and 20, and may be, for example, 5 mm or more, 10 mm or more, or 15 mm or more. The distance D is the shortest distance between the antennas 10 and 20, for example, the shortest distance between the antenna element of the antenna 10 and the antenna element of the antenna 20. The distance D may also be the shortest distance between the point at which the maximum current flows in the antenna element of one of the antennas 10 and 20 and the other antenna.

[0029] The electric circuit 30 is preferably configured to reduce the received power in at least a part of the second frequency band by 3 dB or more compared to the case where the electric circuit 30 is not provided, in that this ensures isolation between the antenna 10 and the antenna 20 in the second frequency band. This makes it possible to suppress signals containing components of the second frequency band from being mixed into the antenna 10 even if the antennas 10 and 20 are close to each other.

[0030] Fig. 2 is a diagram showing a first configuration example and a second configuration example of the electric circuit. Fig. 2 shows electric circuits 30A and 30B as examples of electric circuits that attenuate signals in the second frequency band. Note that only one of electric circuits 30A and 30B may be provided, or both may be provided.

[0031] The electric circuit 30A is provided between the power feeding portion 16 or the vicinity of the power feeding portion 16 and the earth portion 60. The vicinity of the power feeding portion 16 may be the base portion of the antenna element 13 connected to the power feeding portion 16.

[0032] The electric circuit 30A includes a capacitive coupling 30a between the power feeder 16 or a portion near the power feeder 16 and the earth 60. The capacitance of the capacitive coupling 30a is adjusted so that signals including components of the second frequency band that are mixed into the antenna 10 can be attenuated to a predetermined level. The capacitive coupling 30a is formed, for example, by a configuration including a capacitive element or a dielectric layer.

[0033] The electric circuit 30A includes the capacitive coupling 30a, thereby attenuating signals in the second frequency band propagating from the antenna element 13 to the power feeding portion 16. The electric circuit 30A includes the capacitive coupling 30a, thereby attenuating harmonic signals included in the second frequency band propagating from the signal line (inner conductor 51) of the coaxial cable 50 to the power feeding portion 16.

[0034] The coaxial cable 50 is an example of a transmission line. The coaxial cable 50 has an inner conductor 51 and an outer conductor 52. The inner conductor 51 is an example of a signal line of a transmission line, and the outer conductor 52 is an example of a ground conductor of a transmission line. At one end of the coaxial cable 50, the inner conductor 51 is electrically connected to the power supply unit 16, and the outer conductor 52 is grounded to the earth unit 60. The other end of the coaxial cable 50 is electrically connected to a receiving device.

[0035] The electric circuit 30B is provided between the power supply unit 16 and the inner conductor 51. In this example, the electric circuit 30B includes an inductor 30b inserted in series between the power supply unit 16 and the inner conductor 51. The inductance of the inductor 30b is adjusted so that signals containing components of the second frequency band that are mixed into the antenna 10 can be attenuated to a predetermined level. The inductor 30b is, for example, a coil.

[0036] The electric circuit 30B includes the inductor 30b, thereby attenuating signals of the second frequency band propagating from the antenna element 13 to the coaxial cable 50 via the power feeding portion 16. The electric circuit 30B includes the inductor 30b, thereby attenuating harmonic signals included in the second frequency band propagating from the signal line (inner conductor 51) of the coaxial cable 50 to the power feeding portion 16.

[0037] Next, several specific configuration examples of the electric circuit 30A will be described, but each configuration example may or may not include the electric circuit 30B. However, the electric circuit 30A may be simplified by omitting the electric circuit 30B as long as isolation between the antenna 10 and the antenna 20 in the vehicle antenna device 100 can be ensured.

[0038] Fig. 3 is a plan view showing a third configuration example of the electric circuit. Fig. 4 is a cross-sectional view showing the third configuration example of the electric circuit. Figs. 3 and 4 show an electric circuit 30C as an example of an electric circuit that attenuates signals in the second frequency band. In Figs. 3 and 4, when the window glass 1 is attached to a window frame 66 formed in a vehicle body 62 shown in Fig. 4, 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.

[0039] The window glass 1 has a principal surface 2 (an example of a first principal surface) facing the negative side in the Z-axis direction, and a principal surface 3 (an example of a second principal surface facing the opposite side to the first principal surface) facing the positive side in the Z-axis direction. The window glass 1 is attached to a window frame 66, for example, by bonding the peripheral edge of the principal surface 3 to the flange-shaped window frame 66 with an adhesive 65 such as urethane resin. The window frame 66 has a metal portion 63 that faces at least a part of the peripheral edge of the principal surface 3 in a plan view of the window glass 1 from the Z-axis direction. An inner edge 64 of the metal portion 63 forms an opening that is covered by the window glass 1 in a plan view of the window glass 1 from the Z-axis direction. The window glass 1 is an example of a glass sheet for a vehicle, and is a plate-shaped body whose main component is a dielectric such as glass.

[0040] The electric circuit 30C is provided between the vicinity of the power supply unit 16 and the metal part 63. The above-mentioned earth part 60 may include the vehicle-side metal part 63. In this example, the electric circuit 30C includes an extension conductor 31 electrically connected to the power supply unit 16 and an air layer interposed between the extension conductor 31 and the metal part 63. The air layer is an example of a dielectric layer, and in this example, it is interposed between the extension conductor 31 and the inner edge 64. This air layer forms a capacitive coupling. The electric circuit 30C attenuates signals in the second frequency band by including the capacitive coupling formed by this air layer. Note that a dielectric layer other than the air layer may further be included between the extension conductor 31 and the metal part 63.

[0041] In a third configuration example shown in FIGS. 3 and 4 , the antenna element 13, the power supply portion 16, and the extension conductor 31 are formed on the main surface 3 of the window glass 1. The antenna element 13 is an L-shaped linear conductor, but is not limited to an L-shape and may be any shape with multiple open ends, including a T-shape, a loop shape, or a branch. Furthermore, the antenna element 13 may have a (patterned) shape in which multiple linear conductors extend in any direction from the power supply portion 16. The power supply portion 16 is a rectangular planar conductor. The extension conductor 31 is a linear or planar conductor extending from the power supply portion 16. In this example, the extension conductor 31 is a T-shaped conductor including a conductor portion 31a extending from the power supply portion 16 toward the positive side in the Y-axis direction and a conductor portion 31b intersecting with the conductor portion 31a. The conductor portion 31b extends in the X-axis direction along the inner edge 64.

[0042] When the window glass 1 is attached to the window frame 66, the power supply part 16 and the extension conductor 31 do not overlap the metal part 63 in a plan view of the window glass 1. In this way, even if the power supply part 16 and the metal part 63 are relatively far apart when the window glass 1 is attached to the window frame 66, by providing the extension conductor 31, capacitive coupling can be easily formed between the power supply part 16 and the metal part 63, and the coupling capacitance can be adjusted to a desired value.

[0043] Antenna 10 may have a power supply unit 17 electrically connected to a ground conductor of the transmission line (for example, outer conductor 52 of coaxial cable 50 described above). Power supply unit 17 is an example of a second power supply unit, and in this example, is a ground electrode formed on main surface 3. Since antenna 10 has a power supply electrode (power supply unit 16) and a ground electrode (power supply unit 17), a connector terminal (not shown) may be attached to connect antenna 10 (specifically, the electrode of antenna 10) to a coaxial cable.

[0044] FIG. 5 is a plan view showing a fourth configuration example of the electric circuit. FIG. 6 is a cross-sectional view showing the fourth configuration example of the electric circuit. In the fourth configuration example, the description of the same configuration, action, and effect as those of the above configuration examples will be omitted by citing the above description. FIGS. 5 and 6 show an electric circuit 30D as an example of an electric circuit that attenuates signals in the second frequency band. In FIGS. 5 and 6, at least a portion of the extended conductor 31 (in this example, the conductor portion 31b) overlaps with the metal portion 63 in a plan view of the window glass 1.

[0045] The electric circuit 30D is provided between the vicinity of the power supply unit 16 and the metal part 63. In this example, the electric circuit 30D includes an extension conductor 31 electrically connected to the power supply unit 16 and an adhesive 65 interposed between the extension conductor 31 and the metal part 63. The adhesive 65 is an example of a dielectric layer, and in this example, it is interposed between the conductor portion 31b of the extension conductor 31 and the mounting surface of the metal part 63. The adhesive 65 forms a capacitive coupling. The electric circuit 30D attenuates signals in the second frequency band by including the capacitive coupling formed by the adhesive 65. Note that a dielectric layer other than the adhesive 65 may be further included between the extension conductor 31 and the metal part 63.

[0046] When window glass 1 is attached to window frame 66, power supply unit 16 does not overlap metal portion 63 in a plan view of window glass 1, but at least a portion of extension conductor 31 overlaps metal portion 63 in a plan view of window glass 1. In this way, even if power supply unit 16 and metal portion 63 are relatively far apart when window glass 1 is attached to window frame 66, providing extension conductor 31 makes it possible to easily form capacitive coupling between power supply unit 16 and metal portion 63, and to adjust the coupling capacitance to a desired value.

[0047] FIG. 7 is a cross-sectional view showing a fifth configuration example of the electric circuit. In the fifth configuration example, the description of the same configuration, action, and effect as those of the above configuration examples will be omitted by citing the above description. FIG. 7 shows an electric circuit 30E as an example of an electric circuit that attenuates signals in the second frequency band. In FIG. 7, the power supply portion 16 and the extension conductor 31 are sealed in the window glass 1.

[0048] 7, the window glass 1 is a laminated glass in which a glass plate 6 disposed on the exterior side of the vehicle and a glass plate 7 disposed on the interior side of the vehicle are bonded together via an interlayer film 4. The interlayer film 4 is sandwiched between the glass plates 6 and 7.

[0049] The glass plates 6 and 7 are transparent plate-shaped dielectric materials. Either or both of the glass plates 6 and 7 may be translucent. The glass plate 6 is an example of a first glass plate. The glass plate 7 is an example of a second glass plate facing the first glass plate.

[0050] The glass plate 6 has a main surface 6a and a main surface 6b opposite to the main surface 6a in the Z-axis direction. The main surface 6a represents the surface facing the exterior side of the vehicle, and the main surface 6b represents the surface facing the interior side of the vehicle.

[0051] The glass plate 7 has a principal surface 7a facing the principal surface 6b of the glass plate 6 and a principal surface 7b opposite the principal surface 7a in the Z-axis direction. The principal surface 7a represents the surface facing the exterior side of the vehicle, and the principal surface 7b represents the surface facing the interior side of the vehicle. The principal surface 7b is the surface of the glass plate 7 opposite the interlayer film 4.

[0052] The interlayer film 4 is a transparent or semi-transparent dielectric material having dielectric properties and interposed between the glass plate 6 and the glass plate 7. The glass plate 6 and the glass plate 7 are bonded together by the interlayer film 4. Examples of materials that can be used for the interlayer film 4 include thermoplastic polyvinyl butyral (PVB), ethylene vinyl acetate copolymer (EVA), and cycloolefin polymer (COP).

[0053] The electric circuit 30E is provided between the vicinity of the power supply unit 16 and the metal part 63. In this example, the electric circuit 30E includes an extended conductor 31 electrically connected to the power supply unit 16, a glass plate 7, and an adhesive 65 interposed between the extended conductor 31 and the metal part 63. The glass plate 7 and the adhesive 65 are an example of a dielectric layer, and in this example, they are interposed between the extended conductor 31 and the mounting surface of the metal part 63. A capacitive coupling is formed by the glass plate 7 and the adhesive 65. The electric circuit 30E attenuates signals in the second frequency band by including the capacitive coupling formed by the glass plate 7 and the adhesive 65. Note that a dielectric layer different from the glass plate 7 and the adhesive 65 may be further included between the extended conductor 31 and the metal part 63. Note that the glass plate 7 may have a thickness of 0.5 mm to 5.0 mm or 1.5 mm to 2.5 mm. The coupling capacitance between the extended conductor 31 and the metal part 63 may be adjusted taking into account the thickness of the glass plate 7 and the glass composition.

[0054] In the electric circuit 30E, the power supply portion 16 and the extended conductor 31 are formed on the main surface 7a of the glass plate 7. However, the power supply portion 16 and the extended conductor 31 may also be formed on the main surface 6b of the glass plate 6, or may be disposed between multiple interlayer films 4.

[0055] In electric circuit 30E, power supply 16 is electrically connected to power supply 16A, which faces it across glass plate 7, via capacitive coupling formed by glass plate 7. Power supply 16A is a planar conductor formed on main surface 7b of glass plate 7, and is electrically connected to a signal line of a transmission line such as a coaxial cable.

[0056] When the window glass 1 is attached to the window frame 66, the power supply unit 16 does not overlap the metal portion 63 in a plan view of the window glass 1, but at least a portion of the extension conductor 31 overlaps the metal portion 63 in a plan view of the window glass 1. The power supply unit 16 is also enclosed in the window glass 1. In this way, even if the power supply unit 16 and the metal portion 63 are relatively far apart when the window glass 1 is attached to the window frame 66, the provision of the extension conductor 31 makes it possible to easily form capacitive coupling between the power supply unit 16 and the metal portion 63, and to adjust the coupling capacitance to a desired value.

[0057] FIG. 8 is a cross-sectional view showing a sixth configuration example of the electric circuit. In the sixth configuration example, the description of the same configuration, action, and effect as those of the above configuration examples will be omitted by citing the above description. FIG. 8 shows an electric circuit 30F as an example of an electric circuit that attenuates signals in the second frequency band. In the sixth configuration example shown in FIG. 8, the power supply portion 16 is not enclosed in the window glass 1, but the conductor layer 32 is enclosed in the window glass 1.

[0058] The electric circuit 30F is provided between the vicinity of the power supply unit 16 and the metal unit 63. In this example, the electric circuit 30F includes a conductor layer 32 electrically connected to the power supply unit 16 by capacitive coupling, and a glass plate 7 and adhesive 65 interposed between the conductor layer 32 and the metal unit 63. The glass plate 7 and adhesive 65 are an example of a dielectric layer, and in this example, are interposed between the conductor layer 32 and the mounting surface of the metal unit 63. The glass plate 7 and adhesive 65 form a capacitive coupling. The electric circuit 30F attenuates signals in the second frequency band by including the capacitive coupling formed by the glass plate 7 and adhesive 65. Note that a dielectric layer different from the glass plate 7 and adhesive 65 may be further included between the conductor layer 32 and the metal unit 63.

[0059] In the electric circuit 30F, the conductor layer 32 is formed on the main surface 7a of the glass plate 7. However, the conductor layer 32 may also be formed on the main surface 6b of the glass plate 6, or may be disposed between layers of the interlayer film 4 which is formed of multiple layers. Also, Fig. 8 is a cross-sectional view showing a sixth configuration example, and although the planar shape of the conductor layer 32 is not shown, it can be adjusted as appropriate to obtain the desired coupling capacitance.

[0060] In the electric circuit 30F, the conductor layer 32 is electrically connected to the power supply unit 16 that faces the electric circuit 30F across the glass plate 7, via capacitive coupling formed by the glass plate 7. The power supply unit 16 is a planar conductor formed on the main surface 7b of the glass plate 7, and is electrically connected to a signal line of a transmission line such as a coaxial cable.

[0061] When window glass 1 is attached to window frame 66, power supply unit 16 does not overlap metal portion 63 in a plan view of window glass 1, but at least a portion of conductor layer 32 overlaps metal portion 63 in a plan view of window glass 1. In this way, even if power supply unit 16 and metal portion 63 are relatively far apart when window glass 1 is attached to window frame 66, providing conductor layer 32 makes it possible to easily form capacitive coupling between power supply unit 16 and metal portion 63 and adjust the coupling capacitance to a desired value.

[0062] Fig. 9 is a cross-sectional view showing a seventh example of the electrical circuit configuration. In the seventh example of the electrical circuit configuration, the same configuration, operation, and effects as those of the above-mentioned examples will not be described by citing the above explanations. Fig. 9 shows an example of an electrical circuit 30G as an electrical circuit that attenuates signals in the second frequency band. In Fig. 9, an antenna 10 having an antenna element 13 and a power supply portion 16 is enclosed in a window glass 1.

[0063] The electric circuit 30G is provided between the power supply unit 16 and the metal unit 63. In this example, the electric circuit 30G includes a conductor layer 32 electrically connected to the power supply unit 16 via capacitive coupling formed by the glass plate 7, and an adhesive 65 interposed between the conductor layer 32 and the metal unit 63. The adhesive 65 is an example of a dielectric layer, and in this example, it is interposed between the conductor layer 32 and the mounting surface of the metal unit 63. A first capacitive coupling is formed by the glass plate 7, and a second capacitive coupling is formed by the adhesive 65. The electric circuit 30G attenuates signals in the second frequency band by including the capacitive coupling formed by the glass plate 7 and the adhesive 65. Note that a dielectric layer other than the adhesive 65 may be further included between the conductor layer 32 and the metal unit 63.

[0064] In the electric circuit 30G, the conductor layer 32 is formed on the main surface 7b of the glass plate 7. The conductor layer 32 is electrically connected to the power supply unit 16 that faces the glass plate 7 via capacitive coupling formed by the glass plate 7. The power supply unit 16 is a planar conductor formed on the main surface 7a of the glass plate 7, and is electrically connected to a signal line of a transmission line such as a coaxial cable via a flat cable (not shown). The flat cable is configured to enter the interior of the window glass 1 from the peripheral edge of the window glass 1 (for example, the glass edge 1a) and come into contact with the power supply unit 16.

[0065] Fig. 10 is a plan view showing an eighth configuration example of the electric circuit. In the eighth configuration example, the description of the same configuration, action, and effect as those of the above-mentioned configuration examples will be omitted by citing the above description. Fig. 10 shows an electric circuit 30H as an example of an electric circuit that attenuates signals in the second frequency band. In Fig. 10, the antenna 10 has a power supply portion 17 electrically connected to a ground conductor of a transmission line (for example, the outer conductor 52 of the above-mentioned coaxial cable 50).

[0066] Power supply section 17 is an example of a second power supply section, and in this example is a ground electrode formed on the same main surface as power supply section 16.

[0067] Electric circuit 30H is provided between power feeding unit 16 and power feeding unit 17. The above-mentioned earth unit 60 may include power feeding unit 17. Electric circuit 30H attenuates signals in the second frequency band by providing capacitive coupling between power feeding unit 16 and power feeding unit 17. The capacitive coupling between power feeding unit 16 and power feeding unit 17 is formed by a configuration including, for example, a capacitive element or a dielectric layer.

[0068] Antenna 10 may have earth element 18 electrically connected to power feeder 17. Earth element 18 is an example of a second element. Providing earth element 18 makes it possible to adjust the antenna gain of antenna 10. Earth element 18 may have any shape with multiple open ends, including an L-shape, a T-shape, a loop shape, or a branch. Furthermore, earth element 18 may have a (pattern) shape in which multiple linear conductors extend in any direction from power feeder 17.

[0069] Fig. 11 is a plan view showing a ninth configuration example of the electric circuit. In the ninth configuration example, the description of the same configuration, action, and effect as those of the above configuration examples will be omitted by citing the above description. Fig. 11 shows an electric circuit 30I as an example of an electric circuit that attenuates signals in the second frequency band. The electric circuit 30I has a capacitive coupling formed by an extension conductor 34 and a gap 36 between the power supply 16 and the power supply 17.

[0070] The electric circuit 30I is provided between the power supply unit 16 and the power supply unit 17. In this example, the electric circuit 30I includes an extension conductor 34 electrically connected to the power supply unit 16 and a gap 36 interposed between the extension conductor 34 and the power supply unit 17. The gap 36 is an example of a dielectric layer, and in this example, is interposed in a direction parallel to the XY plane. A capacitive coupling is formed by the extension conductor 34 and the gap 36. The electric circuit 30I attenuates signals in the second frequency band by including the capacitive coupling formed by the extension conductor 34 and the gap 36.

[0071] The extension conductor 34 is a linear or planar conductor formed on the same plane as the antenna 10. The extension conductor 34 extends from the feed portion 16 so as to form a gap 36 between the extension conductor 34 and the feed portion 17. By extending the extension conductor 34 so as to surround the feed portion 17, the capacitive coupling between the feed portions 16 and 17 can be strengthened, or the desired coupling capacitance can be adjusted.

[0072] Fig. 12 is a perspective view showing a tenth configuration example of the electric circuit. In the tenth configuration example, the description of the same configuration, operation, and effects as those of the above-described configuration examples will be omitted by citing the above description. Fig. 12 shows an electric circuit 30J as an example of an electric circuit that attenuates signals in the second frequency band. Electric circuit 30J has capacitive coupling formed by extension conductor 35 and gap 37 between power supply 16 and power supply 17.

[0073] The electric circuit 30J is provided between the power supply unit 16 and the power supply unit 17. In this example, the electric circuit 30J includes an extension conductor 35 electrically connected to the power supply unit 16 and a gap 37 interposed between the extension conductor 35 and the power supply unit 17. The gap 37 is an example of a dielectric layer, and in this example, is interposed in a direction perpendicular to the XY plane. A capacitive coupling is formed by the extension conductor 35 and the gap 37. The electric circuit 30J attenuates signals in the second frequency band by including the capacitive coupling formed by the extension conductor 35 and the gap 37.

[0074] The extension conductor 35 is a linear or planar conductor that protrudes toward the positive side in the Z-axis direction relative to the plane on which the antenna 10 is formed. The extension conductor 35 extends from the power supply 16 so as to form a gap 36 between the extension conductor 35 and the power supply 17. In the tenth configuration example of the electric circuit shown in FIG. 12, the extension conductor 35 is an L-shaped conductor, but may be a conductor other than an L-shaped conductor.

[0075] Fig. 13 is a perspective view showing an eleventh configuration example of the electric circuit. In the eleventh configuration example, the description of the same configuration, action, and effect as those of the above configuration examples will be omitted by citing the above description. Fig. 13 shows an electric circuit 30K as an example of an electric circuit that attenuates signals in the second frequency band. The electric circuit 30K has a capacitive coupling formed by a conductor layer 39 and a dielectric layer 38 between the power feeding portion 16 and the power feeding portion 17.

[0076] The electric circuit 30K is provided between the power feeding unit 16 and the power feeding unit 17. In this example, the electric circuit 30K includes a dielectric layer 38 and a conductor layer 39. The conductor layer 39 is electrically connected to the power feeding unit 16 by the dielectric layer 38, and the dielectric layer 38 is interposed between the conductor layer 39 and the power feeding unit 17. A capacitive coupling is formed by the conductor layer 39 and the dielectric layer 38. The electric circuit 30K attenuates signals in the second frequency band by including the capacitive coupling formed by the conductor layer 39 and the dielectric layer 38.

[0077] Dielectric layer 38 has a first surface in contact with at least a portion of the surface of power feed unit 16 and at least a portion of the surface of power feed unit 17, and a second surface opposite to the first surface. Conductor layer 39 is formed on the second surface. Capacitive coupling between power feed unit 16 and power feed unit 17 is formed by a laminate of dielectric layer 38 and conductor layer 39.

[0078] Fig. 14 is an exploded perspective view showing a specific structural example of the electric circuit according to the eleventh configuration example shown in Fig. 13. In this example, the conductor layer 39 is disposed between the interlayer film 4 and the glass plate 7, and the dielectric layer 38 is realized by the glass plate 7. In this case, the power supply unit 16 and the power supply unit 17 may be disposed on the main surface 7b of the glass plate 7, and the conductor layer 39 may be disposed on the main surface 7a of the glass plate 7. The conductor layer 39 may also be disposed between the interlayer film 4 and the glass plate 6, or between multiple laminated interlayer films 4. In this case, the dielectric layer 38 may be realized by the glass plate 7 and the interlayer film 4, and the conductor layer 39 may be disposed on the main surface 6b of the glass plate 6.

[0079] Next, the results of measuring the antenna characteristics of the antenna device 100 using an actual window glass 1 will be described.

[0080] 15 is a diagram showing the basic configuration of a vehicle antenna device when the antenna characteristics are actually measured. Antennas 10 and 20 are provided on the glass surface in one area relative to the center line CL of the window glass 1. The dimensional values ​​attached to the dimension lines are in mm.

[0081] The conditions for measuring the antenna characteristics are: Distance D between antenna 10 and antenna 20: 30 mm Window Glass 1: Windshield Antenna 10: Antenna for terrestrial digital television broadcast waves compatible with 470MHz to 710MHz Antenna 20: A communications antenna compatible with sub-6 GHz or lower It was decided.

[0082] 16 is a diagram showing a first example of the results of measuring the transmission coefficient S21 of a vehicle antenna device. The transmission coefficient S21 represents the degree of transmission of a high-frequency signal from the power feed point of antenna 20 to power feed point 16 of antenna 10, and the lower the value, the higher the isolation between antennas 10 and 20.

[0083] The graph represented by the line labeled "ref" is the result of measuring the transmission coefficient S21 of the antenna device having the basic configuration shown in Fig. 15. The graph represented by the line labeled "Example 1" is the result of measuring the transmission coefficient S21 of the antenna device including the electric circuit 30D of the fourth configuration example shown in Fig. 5 and Fig. 6, specifically, the result of measuring in a configuration in which the extension conductor 31 shown in Fig. 5 and Fig. 6 is added to the basic configuration shown in Fig. 15.

[0084] 16, by providing the extension conductor 31 that is capacitively coupled to the metal part 63, the isolation between the antennas 10 and 20 is ensured on the low-frequency side of the second frequency band compared to when the extension conductor 31 is not provided. As a result, when the antennas 10 and 20 are close to each other, unwanted signals corresponding to noise containing components of the second frequency band that are mixed into the antenna 10 are attenuated.

[0085] The conditions for each part of the extension conductor 31 are as follows: Length of conductor portion 31a: 8 mm, Length of conductor portion 31b: 60 mm Width of conductor portions 31a and 31b: 5 mm It was decided.

[0086] FIG. 17 is a diagram showing a second example of the results of actually measuring the transmission coefficient S21 of the vehicle antenna device.

[0087] The graph represented by the line labeled "ref" is the result of measuring the transmission coefficient S21 of the antenna device having the basic configuration shown in Fig. 15. The graph represented by the line labeled "Example 2" is the result of measuring the transmission coefficient S21 of the antenna device including the electric circuit 30K of the eleventh configuration example shown in Fig. 13, specifically, the result of measuring in a configuration in which the dielectric layer 38 and the conductor layer 39 shown in Fig. 13 are added to the basic configuration shown in Fig. 15.

[0088] 17, by capacitively coupling power supply 16 and power supply 17, the isolation between antennas 10 and 20 is ensured on the low-frequency side of the second frequency band compared to when there is no capacitive coupling. As a result, when antennas 10 and 20 are located close to each other, unwanted signals corresponding to noise containing components of the second frequency band that are mixed into antenna 10 are attenuated.

[0089] The conditions for each part of the dielectric layer 38 and the conductor layer 39 are as follows: Area where the dielectric layer 38 overlaps with the power supply parts 16 and 17 in a plan view: 84 mm 2 Thickness of dielectric layer 38: 0.06 mm Dielectric layer 38: acetate It was decided.

[0090] Although the embodiments have been described above, the technology of the present disclosure is not limited to the above-described embodiments, and various modifications and improvements are possible, such as combinations with or substitutions for part or all of other embodiments.

[0091] For example, the glass plate for a vehicle is not limited to a window glass, but may be any other plate-like object such as a display panel.

[0092] Furthermore, the reference numeral 20 may not be an antenna, but may be an electronic device that emits electromagnetic waves in the second frequency band. For example, the in-vehicle system 200 shown in FIG. 1 includes a vehicle antenna device (a window glass 1, an antenna 10, and an electric circuit 30) and an electronic device disposed away from the antenna 10. The electric circuit 30 is provided at least one of between the power supply unit 16 or a portion near the power supply unit 16 and a grounding portion, and between the power supply unit 16 and the signal line of the transmission line. By providing the electric circuit 30 for attenuating signals in the second frequency band in such a location, isolation between the antenna 10 and the electronic device is ensured in the second frequency band. As a result, even if the antenna 10 and the electronic device are located close to each other, signals containing components in the second frequency band that are mixed into the antenna 10 can be attenuated. Specific examples of the electronic device include a sensor, a camera, a communication device, and a lighting device. The above description of the antenna 20 can be applied to a configuration in which the antenna 20 is replaced with an electronic device. The entire contents of the specification, claims, drawings and abstract of Japanese Patent Application No. 2021-200199, filed on December 9, 2021, are hereby incorporated by reference as part of the disclosure of the specification of the present invention. [Explanation of symbols]

[0093] 1. Window glass 1a to 1d Glass rim 2,3 main surfaces 4 Interlayer 5. Light-shielding film 5a Inner edge 6,7 Glass plates 6a, 6b, 7a, 7b Main surfaces 10 Antennas 13 Antenna Element 16, 16A, 17 Power supply section 18 Earth Element 20 Antenna 30, 30A to 30K Electrical Circuit 30a capacitive coupling 30b inductor 31, 34, 35 Extension conductor 31a, 31b Conductor part 32 Conductor layer 36,37 Gap 38 Dielectric Layer 39 Conductor layer 50 coaxial cable 51 Inner conductor 52 outer conductor 60 Earth section 62 Body 63 Metal Parts 64 Common-law marriage 65 Adhesive 66 Window Frame 100 Antenna device 200 In-Vehicle Systems

Claims

1. Glass plates for vehicles; a first antenna provided on the glass plate and capable of receiving or transmitting radio waves in a first frequency band; an electric circuit that attenuates signals in a second frequency band that includes a frequency band higher than the first frequency band; the first antenna has a first feeding portion electrically connected to a signal line of a transmission line and a first element connected to the first feeding portion; The electric circuit is provided at least one between the first power supply portion or a portion near the first power supply portion and a ground portion, and between the first power supply portion and the signal line.

2. The vehicle antenna device according to claim 1 , wherein the electric circuit includes a capacitive coupling between the first power supply portion or a portion near the first power supply portion and the ground portion.

3. 3. The vehicle antenna device according to claim 2, wherein the electric circuit includes a conductor electrically connected to the first feeding portion, and a dielectric layer interposed between the conductor and the ground portion.

4. The vehicle antenna device according to claim 3 , wherein the dielectric layer includes glass.

5. the glass plates include a first glass plate, a second glass plate facing the first glass plate, and an interlayer film disposed between the first glass plate and the second glass plate; the first power supply portion is disposed on a main surface of the second glass plate opposite to the interlayer film, the dielectric layer includes the second glass plate; The vehicle antenna device according to claim 4 , wherein the conductor is disposed between the first glass plate and the second glass plate.

6. the glass plates include a first glass plate, a second glass plate facing the first glass plate, and an interlayer film disposed between the first glass plate and the second glass plate; the first power supply portion is disposed between the first glass plate and the second glass plate, the conductor is disposed on a main surface of the second glass plate opposite to the interlayer film, The vehicle antenna device according to claim 4 , wherein the dielectric layer is located between the main surface and the ground portion.

7. The vehicle antenna device according to claim 3 , wherein the conductor is an extension conductor extending from the first power supply portion or a portion near the first power supply portion.

8. The vehicle antenna device according to claim 1 , wherein the grounding portion includes a metal portion on the vehicle side.

9. the first antenna has a second feeding portion electrically connected to a ground conductor of the transmission line; The vehicle antenna device according to claim 1 , wherein the ground portion includes the second feeding portion.

10. The vehicle antenna device according to claim 9, wherein the first antenna has a second element electrically connected to the second feeding portion.

11. The vehicle antenna device according to claim 1 , wherein the second frequency band is equal to or higher than 617 MHz.

12. The vehicle antenna device according to claim 11, wherein the second frequency band includes a 2.4 GHz band.

13. The vehicle antenna device according to claim 11, wherein the second frequency band includes at least one of a 5.2 GHz band, a 5.3 GHz band, and a 5.6 GHz band.

14. 2. The vehicle antenna device according to claim 1, wherein the electric circuit reduces the received power of at least a part of the second frequency band by 3 dB or more compared to a case where the electric circuit is not provided.

15. The vehicle antenna device according to claim 1 , wherein the first frequency band includes a frequency band included in a VHF band or a UHF band.

16. The vehicle antenna device according to claim 1 , further comprising a second antenna provided on the glass plate and capable of transmitting or receiving radio waves in the second frequency band.

17. The vehicle antenna device according to any one of claims 1 to 16, an electronic device located away from the first antenna, The electronic device emits electromagnetic waves in the second frequency band.

18. The in-vehicle system according to claim 17 , wherein the distance between the first antenna and the electronic device is 100 mm or less.

19. The in-vehicle system according to claim 17 , wherein the electronic device is provided on the glass plate.

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