JP7743802B2 - Vehicle window glass - Google Patents

Description

This disclosure relates to vehicle window glass.

In recent years, vehicle window glass equipped with multiple antennas capable of receiving radio waves in multiple frequency bands, such as AM broadcast waves, FM broadcast waves, terrestrial digital television broadcast waves, and DAB (Digital Audio Broadcasting), has been put into practical use. For example, a vehicle window glass is known that has multiple antennas installed in a blank area above the defogger (see, for example, Patent Document 1).

JP 2014-204190 A

However, with conventional technology, it was difficult to receive radio waves in multiple different frequency bands with high gain.

This disclosure provides a vehicle window glass equipped with multiple antennas capable of receiving radio waves in multiple different frequency bands with high gain.

In one aspect of the present disclosure,
A glass plate and
a first antenna provided on the glass plate;
a second antenna provided on the glass plate and configured to receive radio waves in a frequency band higher than that of the first antenna,
the first antenna has a first feeding section, a feeding element connected to the first feeding section, and a parasitic element arranged away from the feeding element,
the parasitic element includes a bent element including an L-shaped or U-shaped portion;
The vehicle window glass is provided, wherein the bending element includes a first element including a portion that is capacitively coupled to a portion of the power supply element, and a second element that is positioned farther away from the power supply element than the first element.

One aspect of the present disclosure provides a vehicle window glass equipped with multiple antennas capable of receiving radio waves in multiple different frequency bands with high gain.

1 is a plan view showing one configuration example of a vehicle window glass according to a first embodiment. FIG. FIG. 10 is a plan view showing a configuration example of a vehicle window glass according to a second embodiment. FIG. 11 is a plan view showing one configuration example of a vehicle window glass according to a third embodiment. FIG. 10 is a plan view showing one configuration example of a vehicle window glass according to a fourth embodiment. FIG. 10 is a diagram showing an example of actual measurement results of frequency characteristics of antenna gain in the band of horizontally polarized FM broadcast waves. FIG. 10 is a diagram showing an example of actual measurement results of frequency characteristics of antenna gain in the band of vertically polarized FM broadcast waves. FIG. 10 is a diagram showing an example of the results of measurements of the frequency characteristics of antenna gain in the DAB Band III band of vertically polarized waves. FIG. 10 is a diagram showing an example of the results of measurements of the frequency characteristics of the antenna gain in the band of horizontally polarized FM broadcast waves when the length _LC is changed. FIG. 10 is a diagram showing an example of the results of measurements of the frequency characteristics of the antenna gain in the band of vertically polarized FM broadcast waves when the length _LC is changed. FIG. 10 is a diagram showing an example of the measurement results of the frequency characteristics of the antenna gain in the band of horizontally polarized FM broadcast waves when the path length _LH between the open ends of a bending element including an L-shaped or U-shaped portion is changed. FIG. 10 is a diagram showing an example of the measurement results of the frequency characteristics of the antenna gain in the band of vertically polarized FM broadcast waves when the path length _LH between the open ends of a bending element including an L-shaped or U-shaped portion is changed. FIG. 10 is a diagram showing an example of actual measurement results of frequency characteristics of antenna gain in the DAB Band III band of vertically polarized waves when the shortest distance D is changed. FIG. 10 is a diagram showing an example of the results of measurements of the frequency characteristics of antenna gain in the band of horizontally polarized terrestrial digital television broadcast waves when the shortest distance D is changed.

Each embodiment will be described below 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. Deviations in directions such as parallel, right-angled, orthogonal, horizontal, vertical, up-down, left-right, etc. are permitted to the extent that they do not impair the function and effect of the embodiment. The shape of corners is not limited to right angles and may be rounded in an arched shape. Furthermore, "opposing" is not limited to meaning completely opposing, but may also mean partially opposing, and "overlapping" is not limited to meaning completely overlapping, but may also mean partially overlapping.

Examples of vehicle window glass in this embodiment 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, and roof glass attached to the roof of the vehicle. Vehicle window glass is not limited to these examples, and may be, for example, a window glass in which the roof glass is integrated with either or both of the windshield and rear glass.

Figure 1 is a plan view showing an example of the configuration of a vehicle window glass according to the first embodiment. The window glass 101 shown in Figure 1 is an example of a vehicle window glass, and is attached to a window frame 210 formed on a vehicle body. The window glass 101 comprises a glass plate 10. Figure 1 shows the window glass 101 in a plan view from the normal direction of the surface of the glass plate 10.

In Figure 1, the first direction A1, second direction A2, third direction A3, and fourth direction A4 indicate directions in a plan view of the glass plate 10. The second direction A2 indicates the direction opposite to the first direction A1, and the fourth direction indicates the direction opposite to the third direction A3. In this embodiment, of the first direction A1, second direction A2, third direction A3, and fourth direction A4, any two adjacent directions intersect at a right angle (which may include an approximately right angle). These descriptions also apply to other plan views.

The window frame 210 is a conductive part that can be grounded and is also called a flange. The window frame 210 has a frame edge 211 that forms an opening that is covered by the window glass 101. The window frame 210 is an example of a metal part of a vehicle.

The glass plate 10 is an example of a glass plate for a vehicle and is a transparent or translucent plate-shaped dielectric. The glass plate 10 has an outer peripheral edge 12 that is attached to the window frame 210. The glass plate 10 is attached to the window frame 210 so that the outer peripheral edge 12 overlaps the window frame 210 when viewed from a plane from inside the vehicle.

The window glass 101 has an antenna 30 and an antenna 40 on the glass plate 10.

The antenna 30 is an example of a first antenna and is provided on the glass plate 10. The antenna 30 is configured to be able to receive radio waves in a first frequency band _F1 . The antenna 40 is an example of a second antenna and is provided on the glass plate 10. The antenna 40 is configured to be able to receive radio waves in a second frequency band _F2 that is higher than the _first frequency band F1.

The shape of the antenna 30 is suitable for transmitting and receiving radio waves in the VHF (Very High Frequency) band, which has a frequency of 30 MHz to 300 MHz. The antenna 40 is suitable for transmitting and receiving radio waves in the VHF band, the UHF (Ultra High Frequency) band, which has a frequency of 300 MHz to 3 GHz, or the SHF (Super High Frequency) band, which has a frequency of 3 GHz to 30 GHz. For example, the first frequency band _F1 may be set to the FM broadcast wave band (76 MHz to 108 MHz) included in the VHF band. The second frequency band _F2 may be set to the DAB Band III band (170 MHz to 240 MHz) included in the VHF band or the terrestrial digital television broadcast wave band (470 MHz to 710 MHz) included in the UHF band. Furthermore, the second frequency band _F2 may be set to transmit and receive radio waves of Wi-Fi, which is a wireless LAN (Local Area Network), or may be set to transmit and receive radio waves in the 600 MHz to 6 GHz frequency band (sub6) used in the fifth generation communication (5G) standard.

The antenna 30 has a power feed section 31, a power feed element 32, and a parasitic element 39.

The power supply unit 31 is an example of a first power supply unit, and is, for example, an electrode for power supply. The power supply unit 31 is provided near the outer edge 12 of the glass sheet 10 so that it is located near the frame edge 211 when the window glass 101 is attached to the window frame 210. The power supply unit 31 is electrically connected to one end of a power supply line (for example, one end of a signal line of a coaxial cable) via a conductive member such as a connector. The other end of the power supply line is connected to a communication device such as a receiver. For implementation purposes, the shape of the power supply unit 31 is preferably a rectangular or polygonal shape, such as a square, approximately square, rectangle, or approximately rectangular, but is not limited to these and may be other shapes such as a circle, approximately circle, ellipse, or approximately ellipse.

The power supply element 32 is an element connected to the power supply unit 31. The power supply element 32 is a linear conductor extending from the power supply unit 31 to an open end 32b, which is the end opposite the power supply unit 31. The power supply element 32 includes a portion 32a extending in the first direction A1. In FIG. 1, the power supply element 32 has the open end 32b at its tip in the first direction A1, but this is not limited thereto. The power supply element 32 may also have an element that extends from its tip in the first direction A1 and bends in a direction different from the first direction A1, for example, in the fourth direction A4.

The parasitic element 39 is positioned away from the feed element 32 and is not connected to the feed section 31 or the feed element 32. The parasitic element 39 is a linear conductor including a bent element 34 that includes an L-shaped portion. The bent element 34 includes a first element 35 that includes a portion that is capacitively coupled with a part of the feed element 32, and a second element 36 that is positioned farther away from the feed element 32 than the first element 35. In this example, the L-shaped portion included in the bent element 34 is formed by the first element 35 and the second element 36.

The antenna 30 has a parasitic element 39 including a bent element 34, and therefore has an improved antenna gain in the first frequency band _F1 compared to a configuration without the parasitic element 39. The window glass 101 also has an antenna 40 that is suitable for receiving radio waves in a second frequency band F2 that is higher than the first frequency band _{F1 .} Therefore, the window glass 101 can be provided as a vehicle window glass equipped with multiple antennas that can receive radio waves in multiple different frequency bands with high gain.

Furthermore, the window glass of this embodiment can receive radio waves in both frequency bands with high gain even when the antennas 30, 40 that receive radio waves in two different frequency bands are close to each other, so it can be used on side windows such as rear windows, which have a smaller area than other window glass.

The first element 35 may include a portion 35a that is capacitively coupled to the portion 32a of the power supply element 32. The portion 35a is spaced from the portion 32a by a distance d that allows capacitive coupling. In the example of FIG. 1, the portion 35a that is capacitively coupled to the portion 32a is located on the third direction A3 side of the portion 32a, but may also be located on the fourth direction A4 side of the portion 32a. Furthermore, if the power supply element 32 has a portion that bends from the first direction A1 to the third direction A3 or the fourth direction A4, the first element 35 may have a portion 35a that is capacitively coupled to the portion 32a extending in the third direction A3 or the fourth direction A4. In this case, the portion 35a may extend in a direction substantially parallel to the third direction A3 or the fourth direction A4 in which the portion 32a extends, and may run parallel to the portion 32a. The distance d at which capacitive coupling is possible may be, for example, greater than 0 mm and less than or equal to 30 mm, or may be 1 mm or greater and less than or equal to 25 mm, or 2 mm or greater and less than or equal to 20 mm, or 3 mm or greater and less than or equal to 15 mm, or 3 mm or greater and less than or equal to 10 mm.

The bending element 34 may have an open end 34b at the end opposite to the feed element 32. By configuring the bending element 34 to have the open end 34b (e.g., a configuration that does not include a closed loop), the antenna gain in the first frequency band _F1 is improved compared to a configuration that does not have the open end 34b (e.g., a configuration in which the bending element 34 includes a closed loop annular portion). Note that, although the configuration of the bending element 34 in the example of FIG. 1 does not include a closed loop annular portion, it may also be configured to include a closed loop annular portion (e.g., a closed loop configuration in which the end 34b is further folded back and connected to the first element 35).

The bending element 34 may be an element that opens on the antenna 40 side. This allows the area occupied by the antennas 30 and 40 to be reduced compared to an embodiment in which the bending element 34 does not open on the antenna 40 side. In the example of Fig. 1, the antenna 40 is located on the opposite side to the side on which the bending element 34 exists with respect to an imaginary line passing through the two open ends 34a, 34b of the bending element 34 , and therefore the bending element 34 can be said to open on the antenna 40 side.

The antenna 40 may overlap the area where the bending element 34 is projected in the direction in which the bending element 34 opens. This allows the area occupied by the antennas 30 and 40 to be reduced compared to a configuration in which the antenna 40 does not overlap the area where the bending element 34 is projected in the direction in which the bending element 34 opens. In the example of Figure 1, the direction in which the bending element 34 opens is the opposite side to the side on which the antenna 40 exists, relative to an imaginary line passing through the two open ends 34a, 34b of the bending element 34.

In this example, the antenna 40 is located on the third direction A3 side relative to the power supply element 32, but it may also be located on the fourth direction A4 side relative to the power supply element 32.

When the length over which the first element 35 runs parallel to the feed element 32 and is capacitively coupled is defined as L _C , if L _C is 20 mm or greater (L _C ≧20 mm), the antenna gain of the antenna 30 in the first frequency band _F1 is improved. In terms of improving the antenna gain of the antenna 30 in the first frequency band _F1 , L _C is preferably 25 mm or greater, and more preferably 30 mm or greater. The upper limit of L _C is not particularly limited as long as radio waves in the first frequency band _F1 can be received with the desired gain, but the upper limit of L _C may be, for example, 400 mm or 300 mm.

The first element 35 runs parallel to the end of the feed element 32 and is capacitively coupled to it, thereby improving the antenna gain of the antenna 30 in the first frequency band _F1 . In the example of FIG. 1 , the first element 35 includes a portion 35a running parallel to a portion 32a, which is the end of the feed element 32 and includes the open end 32b, and the portion 35a is capacitively coupled to the portion 32a. Note that the first element 35 may run parallel to an intermediate portion of the feed element 32 that does not include the open end 32b, rather than running parallel to the end of the feed element 32 that includes the open end 32b. Furthermore, the feed element 32 may run parallel to an intermediate portion of the first element 35 that does not include the open end 34a, rather than running parallel to the end of the first element 35 that includes the open end 34a, and be capacitively coupled to it. In this case, the antenna gain of the antenna 30 in the first frequency band _F1 is still ensured.

The path length from the open end 34a of the bending element 34 on the side of the feeding element 32 to the open end 34b of the bending element 34 on the opposite side of the feeding element 32 is defined as _LH , the wavelength in air of the radio wave of the first frequency band _F1 received by the antenna 30 is defined as λ, and the wavelength shortening rate of the glass plate 10 is defined as k. In this case, the path length _LH is expressed as follows:
1/8×λ×k ≦ L _H ≦ 3/8×λ×k ... Formula 1a
When the above condition is satisfied, the antenna gain of the antenna 30 in the first frequency _{band F1} is improved.
7/50×λ×k ≦ L _H ≦ 9/25×λ×k ... Formula 1b
is preferred,
3/20×λ×k ≦ L _H ≦ 7/20×λ×k ...Formula 1c
is more preferred.

When the shortest distance D between the second element 36 and the antenna 40 is 20 mm or more, the minimum value of the antenna gain in the second frequency band _F2 of the antenna 40 is improved. In order to improve the minimum value of the antenna gain in the second frequency band _F2 of the antenna 40, the shortest distance D is preferably 50 mm or more, more preferably 100 mm or more, and even more preferably 150 mm or more. The upper limit of the shortest distance D is not particularly limited as long as the second element 36 and the antenna 40 do not protrude from the glass plate 10.

When a portion of the power supply element 32 and at least a portion of the first element 35 are formed to extend in a substantially horizontal direction when the glass sheet 10 is attached to a vehicle, the antenna gain of the antenna 30 for horizontal polarization is improved. In the example of FIG. 1, both the power supply element 32 and the first element 35 include portions extending in the first direction A1. More specifically, in the example of FIG. 1, the power supply element 32 includes a portion 32a extending in the first direction A1, and the first element 35 includes a portion 35a extending in the first direction A1. When the glass sheet 10 is attached to the window frame 210 of the vehicle, if the first direction A1 is substantially parallel to the horizontal plane, the antenna gain of the antenna 30 for horizontal polarization is improved.

The second element 36 may include a portion that extends in a direction substantially perpendicular to the direction in which the portion included in the first element 35 extends. In the example of FIG. 1, the second element 36 includes a portion that extends in the third direction A3. More specifically, in the example of FIG. 1, the second element 36 includes a portion that extends in the third direction A3. When the glass plate 10 is attached to the window frame 210 of the vehicle, if the third direction A3 is substantially perpendicular to the horizontal plane, the antenna gain of the vertically polarized waves of the antenna 30 is improved.

In the example of Figure 1, the antenna 40 includes a power feed section 41 and an element 42 connected to the power feed section 41.

Power supply unit 41 is an example of a second power supply unit, and is, for example, a power supply electrode. The shape and location of power supply unit 41 are similar to those of power supply unit 31.

The antenna 40 may further include a power supply unit 43. The power supply unit 43 is an example of a third power supply unit, and is, for example, a ground electrode. The shape and location of the power supply unit 43 are similar to those of the power supply unit 31. In other words, the antenna 40 may be a monopole type or a bipole type.

Element 44 is an element connected to power supply 43. Element 44 is a linear conductor extending from power supply 43 to open end 44a, which is the end opposite power supply 43.

In the example shown in FIG. 1, antenna 40 includes a power feeder 41 and an element 42 connected to power feeder 41. Element 42 is a linear conductor extending from power feeder 41 to an open end 42a, which is the end opposite power feeder 41. In this example, element 42 is located between power feeder element 32 and element 44.

When the glass plate 10 is attached to the vehicle, it is preferable that the power supply units 31 and 41 be aligned along a metal part of the vehicle (in this example, one end edge 211a of the frame edge 211 of the window frame 210). This brings the power supply units 31 and 41 closer to each other, allowing for a compact power supply structure to the power supply units 31 and 41. Furthermore, it is even more preferable that the power supply unit 43, together with the power supply units 31 and 41, be aligned along a metal part of the vehicle.

Figure 2 is a plan view showing an example configuration of a vehicle window glass of the second embodiment. In the second embodiment, explanations of the configuration, actions, and effects similar to those of the above-described embodiments will be omitted or simplified by incorporating the above explanations. The window glass 102 of the second embodiment shown in Figure 2 differs from the window glass 101 of the first embodiment in that the bending element 34 includes a U-shaped portion.

In the example shown in Figure 2, the bending element 34 further includes a third element 37, and the U-shaped portion included in the bending element 34 is formed by the first element 35, the second element 36, and the third element 37. The third element 37 includes a portion that extends in a direction different from the extension direction of the first element 35 and the second element 36. In this example, the third element 37 is a linear conductor that is connected to the end of the second element 36 extending in the third direction A3 and extends from that end in the second direction A2 to the open end 34b.

The antenna 30 has a parasitic element 39 including the third element 37, and therefore has an improved antenna gain in the first frequency band _F1 compared to an antenna without the parasitic element 39. Therefore, the window glass 102 can be provided as a vehicle window glass equipped with a plurality of antennas that can receive radio waves in a plurality of different frequency bands with high gain.

Figure 3 is a plan view showing an example configuration of a vehicle window glass of the third embodiment. In the third embodiment, explanations of the configuration, actions, and effects similar to those of the above-mentioned embodiments will be omitted or simplified by incorporating the above explanations. The window glass 103 of the third embodiment shown in Figure 3 differs from the window glass 102 of the second embodiment in that the first element 35 includes a crank-shaped portion 38. Note that in the window glass 101 of Figure 1, the first element 35 may also include a crank-shaped portion.

In Figure 3, the crank-shaped portion 38 is connected to the second element 36. The crank-shaped portion 38 is formed by a first portion 38a and a second portion 38b. The first portion 38a extends in a direction different from the extension direction of the portion 35a (in this example, the third direction A3). The second portion 38b extends in a direction different from the extension direction of the first portion 38a (in this example, the first direction A1).

The antenna 30 has a parasitic element 39 including the crank-shaped portion 38, and therefore has an improved antenna gain in the first frequency band _F1 compared to an antenna without the parasitic element 39. Therefore, the window glass 103 can be provided as a vehicle window glass equipped with a plurality of antennas that can receive radio waves in a plurality of different frequency bands with high gain.

Figure 4 is a plan view showing an example configuration of a vehicle window glass of the fourth embodiment. In the fourth embodiment, explanations of the configuration, actions, and effects similar to those of the above-mentioned embodiments will be omitted or simplified by incorporating the above explanations. The window glass 104 of the fourth embodiment shown in Figure 4 differs from the window glass 102 of the second embodiment in that the bending element 34 includes auxiliary elements 51 and 52. The bending element 34 may include one or both of the auxiliary elements 51 and 52. Note that in the window glasses 101, 102, and 103 of Figures 1, 2, and 3, the bending element 34 may include one or both of the auxiliary elements 51 and 52.

In FIG. 4, auxiliary element 51 is connected to first element 35 or second element 36. Auxiliary element 51 is, for example, a linear conductor extending in first direction A1 from the connection between first element 35 and second element 36 to open end 34c. On the other hand, auxiliary element 52 is connected to third element 37 or second element 36. Auxiliary element 52 is a linear conductor extending in first direction A1 from the connection between third element 37 and second element 36 to open end 34d. Auxiliary element 51 is an example of a first auxiliary element. Auxiliary element 52 is an example of a second auxiliary element.

In the antenna 30, the bending element 34 includes one or both of the auxiliary elements 51 and 52, which makes it easier to tune the antenna gain for the first frequency band _F1 compared to a configuration in which the bending element 34 does not include either of the auxiliary elements 51 and 52. Therefore, the window glass 104 can be provided as a vehicle window glass equipped with multiple antennas that can receive radio waves in multiple different frequency bands with high gain.

Figure 5 shows an example of measured results of the frequency characteristics of antenna gain in the band of horizontally polarized FM broadcast waves. Figure 6 shows an example of measured results of the frequency characteristics of antenna gain in the band of vertically polarized FM broadcast waves. Figure 7 shows an example of measured results of the frequency characteristics of antenna gain in the band of vertically polarized DAB Band III. Figures 5 to 7 show examples of window glass 102 (Figure 2) and window glass 103 (Figure 3), and show window glass 102 (Figure 2) without parasitic element 39 as a comparative example. In Figures 5 to 7, antenna 30 is an antenna configured to receive radio waves in the frequency band of FM broadcast waves. Antenna 40 is an antenna configured to receive radio waves in the frequency band of DAB Band III.

As shown in Figures 5 and 6, window panes 102 and 103 with parasitic element 39 had improved antenna gain in the FM broadcast wave frequency band of antenna 30 compared to window panes without parasitic element 39. Furthermore, as shown in Figures 5 to 7, window panes 102 and 103 with parasitic element 39 suppressed a decrease in antenna gain in the DAB Band III frequency band of antenna 40, even when antennas 30 and 40, which receive radio waves in two different frequency bands, were located close to each other.

In the actual measurements shown in Figures 5 to 7, the conditions for the dimensions of each part of the window glass 102 (Figure 2) and the window glass 103 (Figure 3) are as follows:
Path length from the power supply portion 31 to the open end 32b (FIGS. 2 and 3): 350 mm
Path length _LH from open end 34a to open end 34b (FIG. 2): 760 mm
Path length _LH from open end 34a to open end 34b (FIG. 3): 760 mm
Path length from the power supply portion 41 to the open end 42a (FIGS. 2 and 3): 200 mm
Path length from the power supply portion 43 to the open end 44a (FIGS. 2 and 3): 780 mm
Length L _C (Figures 2 and 3): 170 mm
Distance d (Figures 2 and 3): 10 mm
Shortest distance D (Figures 2 and 3): 170 mm
Wavelength shortening rate k of glass plate: 0.64
It was decided.

Fig. 8 shows an example of measurement results of the frequency characteristics of antenna gain in the band of horizontally polarized FM broadcast waves when the length _LC is changed. Fig. 9 shows an example of measurement results of the frequency characteristics of antenna gain in the band of vertically polarized FM broadcast waves when the length _LC is changed. Figs. 8 and 9 show an example of window glass 103 (Fig. 3) and, as a comparative example, window glass in which the parasitic element 39 is removed from window glass 103 (Fig. 3). In Figs. 8 and 9, antenna 30 is an antenna configured to receive radio waves in the frequency band of FM broadcast waves. Antenna 40 is an antenna configured to receive radio waves in the frequency band of DAB Band III.

As shown in Figures 8 and 9, the longer the length _LC , the stronger the capacitive coupling, so the window glass 103 having the parasitic element 39 improved the antenna gain of the antenna 30 in the frequency band of FM broadcast waves.

In the actual measurements of FIGS. 8 and 9, the conditions for the dimensions of each part of the window glass 103 (FIG. 3) are as follows:
Path length from power supply 31 to open end 32b (FIG. 3): 350 mm
Path length _LH from open end 34a to open end 34b (FIG. 3): 677 mm
Path length from the power supply 41 to the open end 42a (FIG. 3): 200 mm
Path length from the power supply 43 to the open end 44a (FIG. 3): 780 mm
Length L _C (Fig. 3): Change Distance d (Fig. 3): 3 mm
Shortest distance D (Figure 3): 200 mm
Wavelength shortening rate k of glass plate: 0.64
It was decided.

FIG. 10 shows an example of measurement results of the frequency characteristics of the antenna gain in the band of horizontally polarized FM broadcast waves when the path length _LH between the open ends 34a and 34b is changed. FIG. 11 shows an example of measurement results of the frequency characteristics of the antenna gain in the band of vertically polarized FM broadcast waves when the path length _LH between the open ends 34a and 34b is changed. FIG. 10 shows an example of an embodiment of window glass 103 (FIG. 3). In FIG. 10, antenna 30 is an antenna configured to receive radio waves in the frequency band of FM broadcast waves. Antenna 40 is an antenna configured to receive radio waves in the frequency band of DAB Band III. Note that when the path length _LH is 490 mm and 590 mm, the third element 37 is removed from window glass 103 (FIG. 3).

10 and 11, when the path length _LH is 490 mm to 940 mm, the antenna gain of the antenna 30 in the frequency band of FM broadcast waves is improved compared to when the path length _LH is 1040 mm. When the path length _LH is 490 mm to 940 mm, the above formula 1a is satisfied if the first frequency band _F1 is the frequency band of FM broadcast waves (76 MHz to 108 MHz) and the wavelength shortening rate k is 0.64.

In the actual measurements of FIGS. 10 and 11, the conditions such as the dimensions of each part of the window glass 103 (FIG. 3) are as follows:
Path length from power supply 31 to open end 32b (FIG. 3): 350 mm
Path length _LH from open end 34a to open end 34b (FIG. 3): variable Path length from power supply part 41 to open end 42a (FIG. 3): 200 mm
Path length from the power supply 43 to the open end 44a (FIG. 3): 780 mm
Length L _C (Fig. 3): 170 mm
Distance d (Figure 3): 10 mm
Wavelength shortening rate k of glass plate: 0.64
It was decided.

Figure 12 shows an example of the measured frequency characteristics of antenna gain in the DAB Band III band for vertically polarized waves when the minimum distance D is changed. Figure 12 shows an example of window glass 104 (Figure 4). In Figure 12, antenna 30 is an antenna configured to receive radio waves in the FM broadcast wave frequency band. Antenna 40 is an antenna configured to receive radio waves in the DAB Band III frequency band.

As shown in Figure 12, when the minimum distance D is 20 mm to 300 mm, the minimum antenna gain in the DAB Band III band for vertical polarization of the antenna 40 is improved compared to when the minimum distance D is 10 mm, regardless of whether auxiliary elements 51 and 52 are present.

In addition, when the actual measurements were taken in FIG. 12, the conditions such as the dimensions of each part of the window glass 104 (FIG. 4) were as follows:
Path length from power supply 31 to open end 32b (FIG. 4): 350 mm
Path length _LH from open end 34a to open end 34b (FIG. 4): variable Path length from power supply part 41 to open end 42a (FIG. 4): 250 mm
Path length from the power supply 43 to the open end 44a (FIG. 4): 780 mm
Length L _C (Fig. 4): 170 mm
Distance d (Figure 4): 10 mm
Shortest distance D (Figure 4): Change Wavelength shortening rate k of glass plate: 0.64
It was decided.

Figure 13 shows an example of the results of actual measurements of the frequency characteristics of antenna gain in the band of horizontally polarized terrestrial digital television broadcast waves when the shortest distance D is changed. Figure 13 shows an example of window glass 104 (Figure 4). In Figure 13, antenna 30 is an antenna configured to be able to receive radio waves in the frequency band of FM broadcast waves. Antenna 40 is an antenna configured to be able to receive radio waves in the frequency band of terrestrial digital television broadcast waves.

As shown in Figure 13, when the minimum distance D is 150 mm, the minimum value of the antenna gain in the band of horizontally polarized terrestrial digital television broadcast waves of the antenna 40 is improved compared to when the minimum distance D is 10 mm, regardless of whether the auxiliary elements 51 and 52 are present or not.

Note that when taking the measurements in Figure 13, the dimensions and other conditions of each part of the window glass 104 (Figure 4) were the same as when taking the measurements in Figure 12.

Although the embodiments have been described above, the technology of the present disclosure is not limited to the above embodiments. Various modifications and improvements are possible, such as combining or substituting part or all of the other embodiments.

For example, the "end" of an element may be the start or end point of the element's extension, or it may be the vicinity of the start or end point, which is the conductor portion just before the start or end point. Furthermore, the "end" of an element may be bent or folded back as long as it does not deviate from the effects of the present invention. Furthermore, the connection between elements may be connected with a curvature.

The antenna element and electrode are formed, for example, by printing and baking a paste containing a conductive metal (e.g., silver paste) on the interior surface of the window glass. However, the method of forming the antenna element and electrode is not limited to this method. For example, the antenna element or electrode may be formed by providing a linear or foil-shaped member containing a conductive material such as copper on the interior or exterior surface of the window glass. Alternatively, the antenna element or electrode may be attached to the window glass with an adhesive or the like, or may be provided inside the window glass itself.

Alternatively, a configuration may be adopted in which a conductor layer forming at least one of an antenna element and an electrode is provided inside or on the surface of a synthetic resin film, and the synthetic resin film with the conductor layer is installed on the interior or exterior surface of the window glass. Furthermore, a configuration may be adopted in which a flexible circuit board on which at least one of an antenna element and an electrode is formed is installed on the interior or exterior surface of the window glass.

The glass plate 10 may also have a light-shielding film along its outer peripheral edge 12, and the electrodes and antenna element may overlap partly or entirely with the light-shielding film in a plan view of the glass plate 10. Specific examples of light-shielding films include ceramics such as black ceramic films. In this case, when the window glass is viewed from outside the vehicle, the overlapping portions with the light-shielding film in a plan view are less visible from outside the vehicle, improving the design of the window glass.

REFERENCE SIGNS LIST 10 Glass plate 12 Outer periphery 21 Power supply part 24b Open end 30 Antenna 31 Power supply part 32 Power supply element 32b Open end 34 Element 34a Open end 34b Open end 35 First element 36 Second element 37 Third element 38 Crank-shaped part 38a First section 38b Second section 39 Parasitic element 40 Antenna 41, 43 Power supply part 42, 44 Element 51 Auxiliary element 52 Auxiliary element 101, 102, 103, 104 Window glass 210 Window frame 211 Frame edge 211a Edge edge

Claims (16)

A glass plate and
a first antenna provided on the glass plate;
a second antenna provided on the glass plate and configured to receive radio waves in a frequency band higher than that of the first antenna,
the first antenna has a first feeding section, a feeding element connected to the first feeding section, and a parasitic element arranged away from the feeding element,
the parasitic element includes a bent element including an L-shaped or U-shaped portion;
The bending element includes a first element including a portion that is capacitively coupled with a portion of the power supply element, and a second element that is positioned farther away from the power supply element than the first element. The vehicle window glass according to claim 1, wherein the bending element has an open end at the end opposite the power supply element. A vehicle window glass according to claim 1 or 2, wherein the parasitic element does not include a closed loop. The vehicle window glass according to claim 1 , wherein the second antenna is located on an opposite side to a side where the bending element is present with respect to an imaginary line passing through the two open ends of the bending element . When the length of the first element running parallel to the power supply element and capacitively coupled with it is defined as L _C ,
L _C ≧ 20 mm
The vehicle window glass according to claim 1 , which satisfies the following: The vehicle window glass according to claim 1 , wherein a portion of the first element runs parallel to and capacitively couples with a portion of the power supply element that includes an open end . Let _LH be the path length from the open end of the bending element on the side of the feed element to the open end of the bending element on the opposite side to the feed element, λ be the wavelength in air of the radio wave in the frequency band received by the first antenna, and k be the wavelength shortening rate of the glass plate.
1/8×λ×k≦L _H ≦3/8×λ×k
The vehicle window glass according to claim 1 , which satisfies the following: A vehicle window glass according to any one of claims 1 to 7, wherein the first element includes a crank-shaped portion connected to the second element. The vehicle window glass according to any one of claims 1 to 8, wherein the shortest distance between the second element and the second antenna is 20 mm or more. A vehicle window glass according to any one of claims 1 to 9, wherein a portion of the power supply element and at least a portion of the first element extend in a substantially horizontal direction when the glass plate is attached to a vehicle. The vehicle window glass according to claim 10, wherein the second element includes a portion extending in a direction substantially perpendicular to the direction in which the portion included in the first element extends. the second antenna includes a second feed portion and an element connected to the second feed portion;
12. The vehicle window glass according to claim 1 , wherein the first power supply portion and the second power supply portion are arranged side by side along a metal portion of the vehicle when the glass plate is attached to the vehicle. The vehicle window glass according to claim 1 , wherein the glass plate is used as a side glass of a vehicle. The vehicle window glass according to claim 1 , wherein the first antenna receives radio waves in an FM broadcast frequency band. 15. The vehicle window glass according to claim 14 , wherein the second antenna receives radio waves in the frequency band of DAB Band III. The vehicle window glass according to claim 14 , wherein the second antenna receives radio waves in a frequency band for terrestrial digital television broadcasting.