Window glass for vehicle

Abstract

To secure a desire gain and suppress the maximum gain.SOLUTION: A window glass for a vehicle, comprises: a glass plate for a window of a vehicle; and an antenna that is provided to the glass plate. The glass plate includes: a first side edge; a second side edge; and an upper edge. The antenna contains: a first power supply part that is positioned near the first side edge from the second side edge; a second power supply part that is positioned to the side opposite to the first side edge of the first power supply part; a first element that is connected to the first power supply part, and is extended to a second direction when a direction directed from the first power supply part to the second power supply part is a first direction, and a direction that is orthogonal to the first direction, and is directed to the first power supply part or the second power supply part from the upper edge is the second direction; a second element that contains a first part crossed with the first element in a cross shape, and a second part extended along the first side edge, and in which an end part of the first direction of the first part is an open end; and a third element that is connected to the first element, and is extended to the first direction.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a window glass for a vehicle.

Background Art

[0002] Conventionally, a window glass for a vehicle equipped with an antenna that transmits and receives radio waves used in ITS (Intelligent Transport Systems) has been known (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] An antenna that transmits and receives radio waves in a predetermined frequency band may be required to ensure a desired reception gain and not have too large a transmission radio wave strength.

[0005] The present disclosure provides a window glass for a vehicle provided with an antenna capable of ensuring a desired gain and suppressing the maximum gain.

Means for Solving the Problems

[0006] The window glass for a vehicle according to the first aspect is a glass plate for a window of a vehicle, and an antenna provided on the glass plate, and the glass plate has a first side edge, a second side edge, and an upper edge, the antenna is a first power feeding portion located closer to the first side edge than the second side edge, and a second power feeding portion located on the side opposite to the first side edge side of the first power feeding portion, The direction from the first power supply unit toward the second power supply unit is defined as the first direction, when a direction orthogonal to the first direction and from the upper edge toward the first power supply unit or the second power supply unit is defined as the second direction, a first element connected to the first power supply unit and extending in the second direction, a second element including a first portion that intersects the first element in a cross shape and a second portion that extends along the first side edge, wherein an end portion of the first portion in the first direction is an open end, and a third element connected to the first element and extending in the first direction.

[0007] The window glass for a vehicle according to the second aspect is the window glass for a vehicle according to the first aspect, wherein the third element may be connected to a third portion where the first element extends in the second direction more than the first portion.

[0008] The window glass for a vehicle according to the third aspect is the window glass for a vehicle according to the second aspect, when a direction opposite to the first direction is defined as the third direction, the antenna may have a fourth element connected to the third portion and extending in the third direction.

[0009] The window glass for a vehicle according to the fourth aspect is the window glass for a vehicle according to the third aspect, wherein the third element and the fourth element may be connected to the same location on the third portion.

[0010] The window glass for a vehicle according to the fifth aspect is the window glass for a vehicle according to the third or fourth aspect, wherein an end portion of the fourth element in the third direction may be an open end.

[0011] The window glass for a vehicle according to the sixth aspect is the window glass for a vehicle according to any one of the third to fifth aspects, wherein the length of the fourth element may be shorter than the length of the third element.

[0012] The vehicle window glass according to the seventh aspect is the vehicle window glass according to any one of the third to sixth aspects, where the fourth element may be located away from the first portion in the second direction.

[0013] The eighth aspect is the vehicle window glass according to any one of the third to seventh aspects, where when the length of the fourth element is L4, the wavelength of the radio wave in the air at the center frequency of a predetermined frequency band is λ, and the wavelength shortening rate by the glass plate is k, 0.2×k×λ×1 / 4≦L4≦1.3×k×λ×1 / 4 may hold.

[0014] The ninth aspect is the vehicle window glass according to any one of the third to eighth aspects, where a sticker containing a conductor may be attached to the glass plate, the sticker may be located away from the second portion in the first direction and away from the fourth element in the second direction.

[0015] The tenth aspect is the vehicle window glass according to any one of the first to ninth aspects, where the third element may be located away from the first portion in the second direction.

[0016] The eleventh aspect is the vehicle window glass according to any one of the first to tenth aspects, where the end portion of the third element in the first direction may be an open end.

[0017] The twelfth aspect is the vehicle window glass according to any one of the first to eleventh aspects, where the end portion of the second portion in the second direction may be an open end.

[0018] The thirteenth aspect is the vehicle window glass according to any one of the first to twelfth aspects, where the first power supply unit and the second power supply unit may be connected by a connection line.

[0019] In the 14th aspect, in the vehicle window glass according to any one of the 1st to 13th aspects, the first power supply unit may be for connecting a signal line, and the second power supply unit may be for grounding.

[0020] In the 15th aspect, in the vehicle window glass according to any one of the 1st to 14th aspects, When the element length from the intersection of the first element and the first portion to the end portion of the second portion in the second direction is L22, the wavelength of the radio wave in the air at the center frequency of a predetermined frequency band is λ, and the wavelength shortening rate by the glass plate is k, 0.4×k×λ≦L22≦0.8×k×λ may hold.

[0021] In the 16th aspect, in the vehicle window glass according to any one of the 1st to 15th aspects, When the element length from the intersection of the first element and the first portion to the end portion of the first portion in the first direction is L21, the wavelength of the radio wave in the air at the center frequency of a predetermined frequency band is λ, and the wavelength shortening rate by the glass plate is k, 0.2×k×λ×1 / 4≦L21≦2.0×k×λ×1 / 4 may hold.

[0022] In the 17th aspect, in the vehicle window glass according to any one of the 1st to 16th aspects, When the length of the third element is L3, the wavelength of the radio wave in the air at the center frequency of a predetermined frequency band is λ, and the wavelength shortening rate by the glass plate is k, 0.5×k×λ×1 / 4≦L3≦2.0×k×λ×1 / 4 may hold.

[0023] In the 18th aspect, in the vehicle window glass according to any one of the 1st to 17th aspects, When the length of the first element is L1, the wavelength of the radio wave in the air at the center frequency of a predetermined frequency band is λ, and the wavelength shortening rate by the glass plate is k, 0.5×k×λ×1 / 4 ≦ L1 ≦ 1.5×k×λ×1 / 4 may be satisfied.

[0024] The 19th aspect is the vehicle window glass according to any one of the 1st to 18th aspects, wherein the glass plate may be a windshield attached to the front part of the vehicle, and the antenna may be an antenna for ITS.

Advantages of the Invention

[0025] According to the present disclosure, it is possible to provide a vehicle window glass provided with an antenna capable of securing a desired gain and suppressing a maximum gain.

Brief Description of the Drawings

[0026]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Modes for Carrying Out the Invention

[0027] Hereinafter, this embodiment will be described with reference to the drawings. For ease of understanding, the scales of the respective parts in the drawings may be different from the actual ones. In directions such as parallel, right-angled, orthogonal, horizontal, vertical, up, down, left, and right, and in terms such as the same and equal, a deviation to the extent that the operations and effects of the embodiment are not impaired is allowed. The shape of the corner is not limited to a right angle and may be arcuate and rounded. Overlap may include the meaning that a part overlaps.

[0028] The X-axis direction, the Y-axis direction, and the Z-axis direction respectively represent directions parallel to the X-axis, directions parallel to the Y-axis, and directions parallel to the Z-axis. The X-axis direction, the Y-axis direction, and the Z-axis direction are orthogonal to each other. The XY plane, the YZ plane, and the ZX plane respectively represent a virtual plane parallel to the X-axis direction and the Y-axis direction, a virtual plane parallel to the Y-axis direction and the Z-axis direction, and a virtual plane parallel to the Z-axis direction and the X-axis direction.

[0029] Each plan view is a view when looking at the glass surface of a glass plate for a window of a vehicle (hereinafter also referred to as "window glass") facing each other. Unless otherwise specified, the window glass attached to the vehicle is shown from the perspective inside the vehicle (view from inside the vehicle). When the window glass is a front glass (windshield) attached to the front part of the vehicle or a rear glass attached to the rear part of the vehicle, unless otherwise specified, the vertical direction of each plan view corresponds to the vertical direction of the vehicle, and the left-right direction of each plan view corresponds to the vehicle width direction of the vehicle. The window glass is not limited to the front glass or the rear glass, and may be, for example, a side glass attached to the side part of the vehicle. When the window glass is a side glass, the vertical direction of each plan view corresponds to the vertical direction of the vehicle, and the left-right direction of each plan view corresponds to the traveling direction (front-rear direction) of the vehicle.

[0030] FIG. 1 is a plan view of a vehicle window glass according to the first embodiment, and illustration of some parts is omitted. The vehicle window glass 201 illustrated in FIG. 1 includes a glass plate 60 for a window of a vehicle and an antenna 101 provided on the glass plate 60. The antenna 101 includes a first power supply unit 50a, a second power supply unit 50b, a first element 10, a second element 20, and a third element 30.

[0031] The direction from the first power supply unit 50a to the second power supply unit 50b is defined as the first direction D1. The direction perpendicular to the first direction D1 and from the upper edge 61a of the glass plate 60 to the first power supply unit 50a or the second power supply unit 50b is defined as the second direction D2. The direction opposite to the first direction D1 is defined as the third direction D3. The direction opposite to the second direction D2 is defined as the fourth direction D4. In this example, the first direction D1, the second direction D2, the third direction D3, and the fourth direction D4 correspond to the negative X-axis direction, the negative Y-axis direction, the positive X-axis direction, and the positive Y-axis direction, respectively.

[0032] FIG. 1 shows a form in which the antenna 101 is arranged in the upper left region of the glass plate 60. The outer shape of the glass plate 60 is substantially rectangular, but other shapes may also be used. The glass plate 60 has an upper edge 61a, a first side edge 61b, and a second side edge 61c. The upper edge 61a represents the upper glass edge of the glass plate 60. The first side edge 61b and the second side edge 61c are a pair of side edges of the glass plate 60. The first side edge 61b is an example of one of the pair of side edges. In this example, the first side edge 61b is the left glass edge of the glass plate 60 and is continuously connected to the upper edge 61a at the upper left corner. The second side edge 61c is an example of the other of the pair of side edges. In this example, the second side edge 61c is the right glass edge of the glass plate 60 and is continuously connected to the upper edge 61a at the upper right corner.

[0033] In the example shown in FIG. 1, in the in-vehicle view, the first side edge 61b and the second side edge 61c are the left edge and the right edge of the glass plate 60, respectively. However, in the out-of-vehicle view, the first side edge 61b and the second side edge 61c may also be the left edge and the right edge of the glass plate 60, respectively.

[0034] In FIG. 1, the connection portion between the upper edge 61a and the first side edge 61b, and the connection portion between the upper edge 61a and the second side edge 61c are connected with curvature, but they may also be connected without curvature. The shapes of the connection portions between other edges are the same.

[0035] Antenna 101 is an example of a glass antenna having a pair of power feeding portions and a plurality of antenna elements, and is a conductor pattern provided planar on a glass plate 60.

[0036] The shape of the antenna 101 is suitable for transmitting and receiving radio waves in the UHF (Ultra High Frequency) band with a frequency of 300 MHz to 3 GHz. Thereby, for example, the antenna 101 can be adapted for wireless communication of telematics services, wireless communication of ITS such as roadside-vehicle communication and vehicle-to-vehicle communication.

[0037] As the conductor patterns of the pair of power feeding portions, the antenna 101 includes a first power feeding portion 50a and a second power feeding portion 50b which are arranged in the vicinity of the upper edge 61a and spaced apart in the left-right direction (vehicle width direction). The antenna 101 is a dipole type antenna having the first power feeding portion 50a and the second power feeding portion 50b as a pair of power feeding points.

[0038] The first power feeding portion 50a is located closer to the first side edge 61b than the second side edge 61c. The first power feeding portion 50a is a power feeding portion for connecting a signal line, and is electrically connected to a signal line of a communication circuit (not shown) via a first conductive member, for example.

[0039] The second power feeding portion 50b is located on the side opposite to the first side edge 61b side of the first power feeding portion 50a. The second power feeding portion 50b is a power feeding portion for grounding, and is electrically connected to a ground portion on the vehicle body side (ground of a communication circuit or the vehicle body, etc.) via a second conductive member, for example.

[0040] Since the second power supply unit 50b to be grounded is located on the side opposite to the first side edge 61b side of the first power supply unit 50a, the radio wave transmitted and received by the antenna 101 can reduce the risk of interfering with the radio wave transmitted and received by an antenna (not shown) disposed between the second power supply unit 50b and the second side edge 61c. When the antenna 101 is used as an antenna for ITS, the frequency band of the radio wave handled by the antenna 101 is relatively close to the frequency band of the radio wave handled by the antenna for terrestrial digital broadcast wave. Therefore, when the antenna (not shown) disposed between the second power supply unit 50b and the second side edge 61c is an antenna for terrestrial digital broadcast wave, the effect of reducing the radio wave interference between the two antennas is particularly improved.

[0041] Since the vehicle window glass 201 is attached to the window frame (flange 70) of the vehicle, a configuration may be adopted in which the first power supply unit 50a is electrically connected to the signal line via a first conductive member protruding from the vicinity of the upper edge 70a of the flange. Since the vehicle window glass 201 is attached to the window frame (flange 70) of the vehicle, a configuration may be adopted in which the second power supply unit 50b is electrically connected to the ground portion via a second conductive member protruding from the vicinity of the upper edge 70a of the flange.

[0042] Instead of the conductive member protruding from the vicinity of the upper edge 70a of the flange, the first conductive member or the second conductive member may be a power supply line such as an AV line or a coaxial cable. A in the AV line represents a vehicle low-voltage electric wire, and V in the AV line represents vinyl. When using a coaxial cable, the inner conductor (signal line) of the coaxial cable is electrically connected to the first power supply unit 50a, and the outer conductor (ground line) of the coaxial cable is electrically connected to the second power supply unit 50b.

[0043] A configuration may be adopted in which a male connector attached to the tip of the coaxial cable is connected to female connectors mounted on the first power supply unit 50a and the second power supply unit 50b. Such a connector facilitates attaching the inner conductor of the coaxial cable to one power supply unit and attaching the outer conductor of the coaxial cable to the other power supply unit. An amplifier for amplifying a signal may be built in the female connector.

[0044] The first power supply unit 50a and the second power supply unit 50b are arranged side by side along the upper edge 61a or the flange upper edge 70a. The first power supply unit 50a and the second power supply unit 50b may be arranged with their vertical positions shifted relative to the illustrated positional relationship. In other words, of the first power supply unit 50a and the second power supply unit 50b, one may be arranged closer to the upper edge 61a than the other.

[0045] The antenna 101 includes a first element 10, a second element 20, and a third element 30 as conductor patterns of antenna elements.

[0046] The first element 10 is connected to the first power supply unit 50a and extends in the second direction D2. In this example, the first element 10 is a linear conductor that extends linearly from the lower end of the first power supply unit 50a to the end 10a in the second direction D2. The first element 10 may be a conductor that is connected to a location different from the lower end of the first power supply unit 50a (for example, the left end of the first power supply unit 50a, etc.) and includes a portion that extends in the second direction D2.

[0047] The second element 20 includes a first portion 21 that intersects the first element 10 at the intersection 10b in a cross shape, and a second portion 22 that extends along the first side edge 61b. In this example, the second element 20 is a linear conductor that includes an L-shaped portion formed by the first portion 21 and the second portion 22. The first portion 21 is, for example, a conductor portion that extends linearly to the end 21a in the first direction D1 and extends in a direction along the upper edge 61a or the flange upper edge 70a. The second portion 22 is, for example, a conductor portion that extends linearly to the end 22a in the second direction D2 and extends in a direction along the first side edge 61b or the flange side edge 70b.

[0048] The second element 20 has an end 21a in the first direction D1 of the first part 21 and an end 22a in the second direction D2 of the second part 22. The ends 21a and 22a are open ends not connected to other conductors. The end 21a in the first direction D1 of the first part 21 may include a portion that bends in a direction different from the first direction D1 (for example, the fourth direction D4 or the second direction D2). The end 22a in the second direction D2 of the second part 22 may include a portion that bends in a direction different from the second direction D2 (for example, the first direction D1 or the third direction D3).

[0049] The first part 21 is cross-shaped and orthogonal to the first element 10, but may intersect the first element 10 at a substantially right angle in a cross shape. The cross-shaped intersection form may include a form in which the first part 21 intersects the first element 10 at an angle of 60° or more and less than 90°.

[0050] The third element 30 is connected to the first element 10 and extends in the first direction D1. In this example, the third element 30 is a linear conductor that extends linearly from the first element 10 to the end 30a in the first direction D1 and is located away from the first part 21 in the second direction D2.

[0051] The end 30a in the first direction D1 of the third element 30 is an open end to which no other conductor is connected. The end 30a may include a portion that bends in a direction different from the first direction D1 (for example, the fourth direction D4 or the second direction D2).

[0052] In the vehicle window glass 201 according to the first embodiment, the antenna 101 includes a first power feeding portion 50a, a second power feeding portion 50b, a first element 10, a second element 20, and a third element 30. The first power feeding portion 50a is located closer to the first side edge 61b than the second side edge 61c. The second power feeding portion 50b is located on the side opposite to the first side edge 61b side of the first power feeding portion 50a. The first element 10 is connected to the first power feeding portion 50a and extends in the second direction D2. The second element 20 includes a first portion 21 that intersects the first element 10 in a cross shape and a second portion 22 that extends along the first side edge 61b. The end portion 21a of the first portion 21 in the first direction D1 is an open end. The third element 30 is connected to the first element 10 and extends in the first direction D1. By having such a configuration, the antenna 101 has effects of ensuring a desired gain and suppressing a maximum gain with respect to the antenna gain of the antenna 101. The antenna gain represents the reception gain when the antenna receives radio waves or the transmission gain when the antenna transmits radio waves.

[0053] When the third element 30 is connected to a third portion 10c where the first element 10 extends in the second direction D2 more than the first portion 21, the effects of ensuring a desired gain and suppressing a maximum gain are enhanced. In this example, the third portion 10c is an element portion from the intersection point 10b to the end portion 10a. The third element 30 is a strip conductor that linearly extends from the end portion 10a of the third portion 10c to the end portion 30a in the first direction D1. Note that the third element 30 may also be an element that is connected to an element portion between the intersection point 10b and the first power feeding portion 50a and extends in the first direction D1.

[0054] The glass plate 60 may have a sticker 62 containing a conductor (e.g., aluminum) attached thereto with a space therebetween the second portion 22 and the first portion 21. The sticker 62 is positioned away from the second portion 22 in the first direction D1 and away from the first portion 21 in the second direction D2. By having the configuration as shown in FIG. 1, the antenna 101 can suppress a decrease in antenna gain when receiving or transmitting vertical polarization or horizontal polarization even if the sticker 62 containing a conductor is disposed in the vicinity of the antenna 101.

[0055] The sticker 62 is, for example, an inspection sticker for notifying an inspection period, and is attached to the upper left region of the window glass in the case of a vehicle with the passenger seat on the left side.

[0056] In the example shown in FIG. 1, the region on the third direction D3 side of the first power feeding portion 50a and on the fourth direction side of the first portion 21 is a blank region where no conductor is formed. By providing this blank region, the antenna 101 capable of ensuring a desired gain and suppressing the maximum gain can be realized with a simple element pattern.

[0057] Let the length of the first element 10 be L1, the wavelength of the radio wave in the air at the center frequency of a predetermined frequency band be λ, and the wavelength shortening ratio by the glass plate 60 be k. In this example, the length L1 corresponds to the element length from the first power feeding portion 50a to the end portion 10a. Regarding the antenna 101, 0.5×k×λ×1 / 4≦L1≦1.5×k×λ×1 / 4 ··· Equation 1a when it holds, the effects of ensuring a desired gain and suppressing the maximum gain are enhanced.

[0058] In terms of improving the effects of ensuring a desired gain and suppressing the maximum gain, 0.6×k×λ×1 / 4≦L1≦1.4×k×λ×1 / 4 ··· Equation 1b is preferable, 0.7×k×λ×1 / 4≦L1≦1.3×k×λ×1 / 4 ··· Equation 1c is more preferable.

[0059] From the intersection point 10b between the first element 10 and the first portion 21 to the end 21a of the first portion 21 in the first direction D1, let the element length be L21, the wavelength of radio waves in air at the center frequency of a predetermined frequency band be λ, and the wavelength shortening rate by the glass plate 60 be k. For the antenna 101, 0.2×k×λ×1 / 4 ≤ L21 ≤ 2.0×k×λ×1 / 4 ··· Equation 2a When this holds, the effects of ensuring a desired gain and suppressing the maximum gain are enhanced.

[0060] In terms of improving the effects of ensuring a desired gain and suppressing the maximum gain, 0.4×k×λ×1 / 4 ≤ L21 ≤ 1.8×k×λ×1 / 4 ··· Equation 2b is preferable, 0.6×k×λ×1 / 4 ≤ L21 ≤ 1.6×k×λ×1 / 4 ··· Equation 2c is more preferable.

[0061] From the intersection point 10b between the first element 10 and the first portion 21 to the end 22a of the second portion 22 in the second direction D2, let the element length be L22, the wavelength of radio waves in air at the center frequency of a predetermined frequency band be λ, and the wavelength shortening rate by the glass plate 60 be k. For the antenna 101, 0.4×k×λ ≤ L22 ≤ 0.8×k×λ ··· Equation 3a When this holds, the effects of ensuring a desired gain and suppressing the maximum gain are enhanced.

[0062] In terms of improving the effects of ensuring a desired gain and suppressing the maximum gain, 0.45×k×λ ≤ L22 ≤ 0.75×k×λ ··· Equation 3b is preferable, 0.50×k×λ ≤ L22 ≤ 0.70×k×λ ··· Equation 3c is more preferable.

[0063] Let the length of the third element 30 be L3, the wavelength of radio waves in air at the center frequency of a predetermined frequency band be λ, and the wavelength shortening rate by the glass plate 60 be k. For the antenna 101, 0.5×k×λ×1 / 4 ≤ L3 ≤ 2.0×k×λ×1 / 4 ··· Equation 4a When this holds, the effects of securing a desired gain and suppressing the maximum gain are enhanced.

[0064] In terms of improving the effects of securing a desired gain and suppressing the maximum gain, 0.7×k×λ×1 / 4 ≤ L3 ≤ 1.8×k×λ×1 / 4 ··· Equation 4b is preferable, 0.9×k×λ×1 / 4 ≤ L3 ≤ 1.6×k×λ×1 / 4 ··· Equation 4c is more preferable.

[0065] The "end portion" of the element may be the starting point or the ending point of the extension of the element, or may be in the vicinity of the starting point or the ending point, which is a conductor portion in front of the starting point or the ending point. The connection portion between the elements may be connected with a curvature.

[0066] The antenna element and the feeding portion are formed, for example, by printing and baking a paste containing a conductive metal (such as silver paste, etc.) on the inner surface of the window glass. However, the method for forming the antenna element and the feeding portion is not limited to this method. For example, the antenna element or the feeding portion may be formed by providing a linear body or a foil body containing a conductive substance such as copper on the inner surface or the outer surface of the window glass. Alternatively, the antenna element or the feeding portion may be attached to the window glass with an adhesive or the like, or may be provided inside the window glass itself. Alternatively, a film-like substrate on which the antenna element or the feeding portion is formed may be attached to the window glass with an adhesive or the like, or may be provided inside the window glass itself. Examples of the film-like substrate include polyethylene terephthalate, polyethylene naphthalate, polycarbonate, polystyrene, cyclic polyolefin, and the like.

[0067] The shape of the power supply unit may be determined according to the shape of the mounting surface of the above-described conductive member or connector. For example, a rectangular shape such as a square, a substantially square shape, a rectangular shape, a substantially rectangular shape, or a polygonal shape is preferable for mounting. In addition, a circular shape such as a circle, a substantially circular shape, an ellipse, or a substantially elliptical shape may also be used.

[0068] A configuration may be adopted in which a conductor layer forming the antenna element and the power supply unit 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 inner surface or the outer surface of the window glass of the vehicle. Further, a configuration may be adopted in which a flexible circuit board on which the antenna element is formed is installed on the inner surface or the outer surface of the window glass of the vehicle.

[0069] Part or all of the power supply unit and the antenna element may be disposed on the shielding film formed on the glass surface at the periphery of the window glass. Specific examples of the shielding film include ceramics such as a black ceramic film. In this case, when viewed from the outside of the vehicle window glass, the part of the power supply unit and the antenna element provided on the shielding film is not visible from the outside of the vehicle, and the window glass with excellent design is obtained.

[0070] FIG. 2 is a plan view of a vehicle window glass according to the second embodiment, with some parts omitted. In the second embodiment, the description of the same configuration, operation, and effects as those in the above-described embodiment is omitted or simplified by referring to the above description. The vehicle window glass 202 illustrated in FIG. 2 includes a glass plate 60 for a window of the vehicle and an antenna 102 provided on the glass plate 60. The antenna 102 is different from the above-described antenna 101 in that it further has a fourth element 40.

[0071] The fourth element 40 is connected to the third portion 10c and extends in the third direction D3. In this example, the fourth element 40 is a linear conductor that extends linearly from the third portion 10c to the end portion 40a in the third direction D3 and is located away from the first portion 21 in the second direction D2.

[0072] The end 40a of the fourth element 40 in the third direction D3 is an open end to which no other conductor is connected. The end 40a may include a portion that bends in a direction different from the third direction D3 (for example, the fourth direction D4 or the second direction D2).

[0073] By adjusting the length L4 of the fourth element 40, it is possible to control (adjust) the antenna gain of the antenna 102, particularly when receiving or transmitting horizontally polarized waves. In a conventional antenna, when the dimensions of each element are adjusted so that the antenna gain improves when receiving or transmitting vertically polarized waves and horizontally polarized waves, the maximum gain (the maximum value of the antenna gain), particularly when receiving horizontally polarized waves, tends to become excessive. For this reason, in a conventional antenna, it may be difficult to adjust the antenna gain, particularly when receiving horizontally polarized waves, to be below a predetermined upper limit gain. Also, in a conventional antenna, when measuring the elevation angle characteristics of the antenna gain, the maximum gain when receiving horizontally polarized waves may exceed a predetermined upper limit gain. Therefore, there may arise a problem of having to redesign the antenna pattern again. Furthermore, when trying to suppress the maximum gain when receiving horizontally polarized waves, there may arise a problem that the antenna gain when receiving vertically polarized waves decreases.

[0074] In the vehicle window glass 202 according to the second embodiment, the antenna 102 has the fourth element 40, so that a desired antenna gain can be ensured for both horizontally polarized waves and vertically polarized waves, and the maximum gain can be suppressed to be below a predetermined upper limit gain. As a result, it is possible to provide an antenna having good transmission and reception characteristics for both horizontally polarized waves and vertically polarized waves.

[0075] In this example, the fourth element 40 is a linear conductor that extends linearly from the end 10a of the third portion 10c in the third direction D3 to the end 40a. Note that the fourth element 40 may be an element that is connected to the element portion between the intersection 10b and the first power feeding portion 50a and extends in the third direction D3.

[0076] The third element 30 and the fourth element 40 are connected to the same location (in this example, the end 10a) of the third portion 10c, so that it is possible to realize an antenna 102 that can ensure a desired gain and suppress the maximum gain.

[0077] When the length L4 of the fourth element 40 is shorter than the length L3 of the third element 30, an antenna 102 capable of securing a desired gain and suppressing the maximum gain can be realized. The length L4 is the element length from the end 10a to the end 40a. The length L3 is the element length from the end 10a to the end 30a. Note that the length L4 may be the same as or longer than the length L3.

[0078] Let the length of the fourth element 40 be L4, the wavelength of the radio wave in the air at the center frequency of a predetermined frequency band be λ, and the wavelength shortening ratio by the glass plate 60 be k. For the antenna 102, 0.2×k×λ×1 / 4 ≦ L4 ≦ 1.3×k×λ×1 / 4 ··· Equation 5a When this holds, the effects of securing a desired gain and suppressing the maximum gain are enhanced.

[0079] In terms of improving the effects of securing a desired gain and suppressing the maximum gain, 0.4×k×λ×1 / 4 ≦ L4 ≦ 1.1×k×λ×1 / 4 ··· Equation 5b is preferable, 0.6×k×λ×1 / 4 ≦ L4 ≦ 0.9×k×λ×1 / 4 ··· Equation 5c is more preferable.

[0080] The sticker 62 is located away from the second portion 22 in the first direction D1 and away from the fourth element 40 in the second direction D2. By having the configuration shown in FIG. 2, the antenna 102 can suppress a decrease in the antenna gain when receiving or transmitting vertical polarization or horizontal polarization even when the sticker 62 containing a conductor is arranged in the vicinity of the antenna 102.

[0081] FIG. 3 is a plan view of a vehicle window glass according to the third embodiment, with illustration of some parts omitted. In the third embodiment, the description of the same configurations, operations, and effects as those in the above-described embodiments is omitted or simplified by referring to the above description. The vehicle window glass 203 illustrated in FIG. 3 includes a glass plate 60 for a window of a vehicle and an antenna 103 provided on the glass plate 60. The antenna 103 is different from the above-described antenna 102 in that it further has a connection line 80.

[0082] When the first power feeding unit 50a and the second power feeding unit 50b are connected by the connection line 80, the effects of ensuring a desired gain and suppressing the maximum gain are enhanced. The connection line 80 is a conductor element that linearly connects between the first power feeding unit 50a and the second power feeding unit 50b. The connection line 80 may be a conductor element that linearly extends from the first power feeding unit 50a to the second power feeding unit 50b in the first direction D1, or may be a conductor element that linearly extends from the second power feeding unit 50b to the first power feeding unit 50a in the third direction D3. The connection line 80 may be a line connecting any location on the end side of the first power feeding unit 50a on the first direction D1 side (in this example, the lower end on the right side of the first power feeding unit 50a) and any location on the end side of the second power feeding unit 50b on the third direction D3 side (in this example, the lower end on the left side of the second power feeding unit 50b).

[0083] FIG. 4 is a diagram showing an example of the result of measuring the directivity of the antenna gain due to the difference in the length L4 of the fourth element for the antenna provided in the vehicle window glass according to the third embodiment. FIG. 4 is a diagram showing an example of the measurement result of the directivity of the antenna 103 in a vehicle in which the vehicle window glass 203 shown in FIG. 3 is attached as a front glass. The front glass is inclined with respect to the ground plane (horizontal plane). FIG. 4 shows the antenna gain measured at the resonance frequency 760 MHz of the fundamental mode of the antenna 103 in the horizontal plane for horizontal polarization and vertical polarization.

[0084] Regarding the concentric circles shown in FIG. 4, the upper side, lower side, right side, and left side respectively represent the front of the vehicle, the rear of the vehicle, the right side of the vehicle, and the left side of the vehicle when the vehicle located at the center of the concentric circles is viewed from the zenith. The unit is dBi.

[0085] The two numerical values written below the concentric circles represent the average value of the antenna gain measured at predetermined angles within the 360° range in the horizontal plane and the maximum value of the antenna gain measured at predetermined angles within the 360° range in the horizontal plane. To confirm the influence of the length L4 of the fourth element 40, with dimensions other than the length L4 fixed and no periodic inspection sticker (an example of the sticker 62 including the conductor) attached, the antenna gain was measured.

[0086] The dimensions of each part during the measurement of the antenna gain of the antenna 103 in FIG. 4 are L1: 45 mm L21: 90 mm L22: 185 mm L3: 100 mm Length of the connection line 80: 10 mm First power feeding part 50a: 20 mm (width) × 14 mm (height) Second power feeding part 50b: 20 mm (width) × 14 mm (height) That is.

[0087] Since the average gain over the entire circumference is -10 dBi or more in all six measurement results shown in FIG. 4, the desired gain of the antenna 103 is ensured. Since the maximum gain is +0.5 dBi or less in all six measurement results shown in FIG. 4, the maximum gain of the antenna 103 is suppressed.

[0088] When L4 is 70 mm and 50 mm, the above formula 5a is satisfied, so for the antenna gain of the antenna 103, the effects of ensuring the desired gain and suppressing the maximum gain are enhanced. In particular, the maximum gain in the case of horizontal polarization can be suppressed to 0 dBi or less. Thus, by adjusting the length L4, the maximum gain, especially in the case of horizontal polarization, can be controlled.

[0089] FIG. 5 is a diagram showing an example of the result of measuring the elevation angle characteristics of the maximum gain of the antenna provided in the vehicle window glass according to the third embodiment under the condition of horizontal polarization. FIG. 6 is a diagram showing an example of the result of measuring the elevation angle characteristics of the maximum gain of the antenna provided in the vehicle window glass according to the third embodiment under the condition of vertical polarization.

[0090] FIGS. 5 and 6 are diagrams showing an example of the result of measuring the directivity of the antenna gain due to the difference in the length L4 of the fourth element for the antenna provided in the vehicle window glass according to the third embodiment. FIGS. 5 and 6 are diagrams showing an example of the measurement result of the directivity of the antenna 103 in a vehicle in which the vehicle window glass 203 shown in FIG. 3 is attached as a windshield. The windshield is inclined with respect to the ground plane (horizontal plane). FIGS. 5 and 6 represent the antenna gain measured at the resonance frequency 760 MHz of the fundamental mode of the antenna 103.

[0091] The elevation angle of 0° indicates the maximum value of the antenna gain measured at each predetermined angle in the range of 360° in the horizontal plane at the launch angle of 0° when the radio wave arrives at an angle of 0° with respect to the horizontal plane of the ground. The elevation angle of 45° indicates the maximum value of the antenna gain measured at each predetermined angle in the range of 360° of the vehicle at the launch angle of 45° when the radio wave arrives at an upward angle of 45° with respect to the horizontal plane of the ground. The elevation angle of 90° indicates the maximum value of the antenna gain measured at each predetermined angle in the range of 360° of the vehicle at the launch angle of 90° when the radio wave arrives at an angle of 90° from above with respect to the horizontal plane of the ground. The maximum value of the antenna gain is measured at a pitch of 5° from the elevation angle of 0° to the elevation angle of 90°.

[0092] In the horizontal polarization of FIG. 5, when L4 = 0 mm, the maximum gain values at elevation angles of 0°, 5°, 10°, and 35° exceed 0 dBi. However, when L4 = 50 mm and L4 = 70 mm, the maximum gain values at any elevation angle do not exceed 0 dBi. On the other hand, in the vertical polarization of FIG. 6, the maximum gain values when L4 = 0 mm, L4 = 50 mm, and L3 = 70 mm do not exceed 0 dBi. Therefore, the length L4 of the fourth element 40 has an effect of suppressing the gain, particularly in horizontal polarization.

[0093] The dimensions of each part during the measurement of FIGS. 5 and 6 of the antenna gain of the antenna 103 are the same as the above dimensions during the measurement of FIG. 4.

[0094] As described above, the embodiments have been explained. However, the above embodiments are presented as examples, and the present invention is not limited by the above embodiments. The above embodiments can be implemented in various other forms, and various combinations, omissions, replacements, changes, etc. can be made without departing from the gist of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are included in the invention described in the claims and its equivalent scope.

Explanation of Reference Numerals

[0095] 10 First element 10a End 10b Intersection point 10c Third part 20 Second element 21 First part 21a End 22 Second part 22a End 30 Third element 30a End 40 Fourth element 40a End 50a First feeding part 50b Second feeding part 60 Glass plate 61a Upper edge 61b First side edge 61c Second side edge 62 Sticker 70 Flange 70a Upper edge of flange 70b Side edge of flange 80 Connecting wire 101, 102, 103 Antenna 201, 202, 203 Vehicle window glass

Claims

1. A glass plate for a window of a vehicle, and an antenna provided on the glass plate, comprising: the glass plate has a first side edge, a second side edge, and an upper edge, the antenna is a first power feeding portion located closer to the first side edge than the second side edge, a second power feeding portion located on the side opposite to the first side edge side of the first power feeding portion, when the direction from the first power feeding portion toward the second power feeding portion is defined as a first direction, when a direction orthogonal to the first direction and from the upper edge toward the first power feeding portion or the second power feeding portion is defined as a second direction, a first element connected to the first power feeding portion and extending in the second direction, a second element including a first portion that intersects the first element in a cross shape and a second portion that extends along the first side edge, wherein an end portion of the first portion in the first direction is an open end, a third element connected to the first element and extending in the first direction, a window glass for a vehicle.

2. The window glass for a vehicle according to claim 1, wherein the third element is connected to a third portion where the first element extends in the second direction more than the first portion.

3. When a direction opposite to the first direction is defined as a third direction, the antenna has a fourth element connected to the third portion and extending in the third direction, the window glass for a vehicle according to claim 2.

4. The window glass for a vehicle according to claim 3, wherein the third element and the fourth element are connected to the third portion at the same location.

5. The window glass for a vehicle according to claim 3, wherein an end portion of the fourth element in the third direction is an open end.

6. The window glass for a vehicle according to claim 3, wherein the length of the fourth element is shorter than the length of the third element.

7. The window glass for a vehicle according to claim 3, wherein the fourth element is located away from the first portion in the second direction.

8. When the length of the fourth element is L4, the wavelength of radio waves in air at the center frequency of a predetermined frequency band is λ, and the wavelength shortening rate by the glass plate is k, 0.2 × k × λ × 1 / 4 ≤ L4 ≤ 1.3 × k × λ × 1 / 4 is satisfied, the window glass for a vehicle according to claim 3.

9. The glass plate has a sticker containing a conductor attached thereto, The sticker is located away from the second part in the first direction and away from the fourth element in the second direction, and is the window glass for a vehicle according to claim 3.

10. The third element is located away from the first part in the second direction, and is the window glass for a vehicle according to claim 1.

11. An end of the third element in the first direction is an open end, and is the window glass for a vehicle according to claim 1.

12. An end of the second part in the second direction is an open end, and is the window glass for a vehicle according to claim 1.

13. The first power supply part and the second power supply part are connected by a connection line, and is the window glass for a vehicle according to claim 1.

14. The first power supply part is for connecting a signal line, and the second power supply part is for grounding, and is the window glass for a vehicle according to claim 1.

15. When an element length from an intersection of the first element and the first part to an end of the second part in the second direction is L22, a wavelength of radio waves in air at a center frequency of a predetermined frequency band is λ, and a wavelength shortening rate by the glass plate is k, 0.4 × k × λ ≤ L22 ≤ 0.8 × k × λ is satisfied, and is the window glass for a vehicle according to claim 1.

16. When an element length from an intersection of the first element and the first part to an end of the first part in the first direction is L21, a wavelength of radio waves in air at a center frequency of a predetermined frequency band is λ, and a wavelength shortening rate by the glass plate is k, 0.2 × k × λ × 1 / 4 ≤ L21 ≤ 2.0 × k × λ × 1 / 4 is satisfied, and is the window glass for a vehicle according to claim 1.

17. When a length of the third element is L3, a wavelength of radio waves in air at a center frequency of a predetermined frequency band is λ, and a wavelength shortening rate by the glass plate is k, 0.5 × k × λ × 1 / 4 ≤ L3 ≤ 2.0 × k × λ × 1 / 4 is satisfied, and is the window glass for a vehicle according to claim 1.

18. When a length of the first element is L1, a wavelength of radio waves in air at a center frequency of a predetermined frequency band is λ, and a wavelength shortening rate by the glass plate is k, 0.5 × k × λ × 1 / 4 ≤ L1 ≤ 1.5 × k × λ × 1 / 4 is satisfied, and is the window glass for a vehicle according to claim 1.

19. The glass plate is a windshield attached to the front part of the vehicle, The antenna is an antenna for ITS, and is the window glass for a vehicle according to any one of claims 1 to 18.

Images