Glass body for vehicles

Abstract

The present invention is a glass body for vehicles, the glass body comprising: a glass plate; a first power supply unit disposed on the glass plate; a second power supply unit disposed on the glass plate and spaced apart from the first power supply unit in a horizontal direction; and an antenna disposed on the glass plate and connected to the first power supply unit and the second power supply unit. The antenna is provided with: a first element having a body connecting the first power supply unit and the second power supply unit; and a second element connected to the first element.

Description

Vehicle glass body

[0001] The present invention relates to a glass body for a vehicle.

[0002] Patent Document 1 discloses a glass antenna for improving reception sensitivity, which is composed of two power feed points and a loop-shaped element connecting the power feed points.

[0003] Japanese Patent Application Laid-Open No. 2017-5711

[0004] The glass antenna described above is formed with a loop-shaped element to improve reception performance, but further improvement in reception performance has been desired. The present invention has been made to solve the above problem, and an object of the present invention is to provide a glass body that can further improve reception performance in an antenna having a loop-shaped element.

[0005] Item 1. A glass body for a vehicle, comprising: a glass sheet; a first power feed portion disposed on the glass sheet; a second power feed portion disposed on the glass sheet and horizontally spaced apart from the first power feed portion; and an antenna disposed on the glass sheet and connected to the first power feed portion and the second power feed portion, wherein the antenna comprises: a first element having a main body portion connecting the first power feed portion and the second power feed portion; and a second element connected to the first element.

[0006] Item 2. The glass body according to Item 1, wherein the main body of the first element is configured by combining a plurality of portions extending substantially horizontally and a plurality of portions extending substantially vertically.

[0007] Item 3. The glass body according to Item 1 or 2, comprising at least one linear extension portion that is connected to any one of the main body portions of the first element and has an open end and extends in one direction.

[0008] Item 4. The glass body according to Item 3, wherein the main body portion is configured by combining a plurality of substantially horizontally extending portions and a plurality of substantially vertically extending portions, and the extension portions are connected to intersections of the substantially horizontally extending portions and the substantially vertically extending portions of the main body portion.

[0009] Item 5. The glass body according to Item 3 or 4, wherein the extension portion extends substantially horizontally.

[0010] Item 6. The glass body according to any one of Items 1 to 5, wherein the second element is configured by combining at least one portion extending substantially horizontally and at least one portion extending substantially vertically.

[0011] Item 7. The glass body according to any one of Items 1 to 6, wherein the second element is connected to a lower portion of the first element.

[0012] Item 8. The glass body according to any one of Items 1 to 7, wherein the length of the first element is 3 / 16κλ to 10 / 16κλ, where λ is the wavelength of the center frequency of the frequency band received by the antenna and κ is the wavelength shortening rate of the glass plate.

[0013] Item 9. The glass body according to any one of items 1 to 8, wherein the antenna is configured to receive a DTV frequency band.

[0014] Item 10. The glass body according to Item 9, wherein the length of the second element is 3 / 16 κλ to 3 / 8 κλ, preferably 1 / 4 κλ to 3 / 8 κλ.

[0015] Item 11. The glass body according to any one of items 1 to 8, wherein the antenna is configured to receive a DAB frequency band.

[0016] Item 12. The glass body according to Item 11, wherein the length of the second element is ½κλ to 9 / 8κλ, preferably ¾κλ to 9 / 8κλ.

[0017] Item 13. The glass body according to any one of Items 1 to 12, wherein the antenna further includes a third element connected to the first feeding portion.

[0018] Item 14. The glass body according to Item 13, wherein the third element has at least a portion extending on the side opposite to the second power supply portion.

[0019] Item 15. The glass body according to any one of Items 6, 13, and 14, wherein the antenna is configured to transmit and receive ITS radio waves.

[0020] According to the present invention, the reception performance of an antenna having a loop-shaped element can be further improved.

[0021] FIG. 1 is a plan view of a vehicle window glass that is an embodiment of the glass body according to the present invention, as viewed from the inside of the vehicle. FIG. 2 is a plan view of an antenna. FIG. 3 is a plan view showing another example of an antenna. FIG. 4 is a plan view showing another example of an antenna. FIG. 5 is a plan view showing another example of an antenna. FIG. 6 is a plan view showing another example of an antenna. FIG. 7 is a plan view showing another example of an antenna. FIG. 8 is a plan view showing another example of an antenna. FIG. 9 is a plan view showing a model 1 of an antenna according to an example. FIG. 10 is a plan view showing a model 2 of an antenna according to an example. FIG. 11 is a plan view showing a model 3 of an antenna according to an example. FIG. 12 is a plan view showing a model 4 of an antenna according to an example. FIG. 13 is a plan view showing a model 5 of an antenna according to an example. FIG. 14 is a graph showing the DAB reception performance of an antenna using model 1 of the example. FIG. 15 is a graph showing the DAB reception performance of an antenna using model 1 of the example. FIG. 16 is a graph showing the DAB reception performance of an antenna using models 1 and 4 of the example. FIG. 17 is a graph showing the DTV reception performance of an antenna using model 2 of the example. 1 is a graph showing the DTV reception performance of an antenna using model 2 of the embodiment. FIG. 2 is a graph showing the DTV reception performance of an antenna using models 2 and 5 of the embodiment. FIG. 3 is a graph showing the ITS reception performance of an antenna using model 3 of the embodiment. FIG. 4 is a graph showing the ITS reception performance of an antenna using model 6 of the embodiment. FIG. 5 is a graph showing the DAB reception performance of antennas according to model 4 of the embodiment and a comparative example.

[0022] Hereinafter, an embodiment in which a glass body according to the present invention is applied to a vehicle window glass will be described with reference to the drawings. FIG. 1 is a plan view showing a vehicle window glass according to this embodiment as viewed from the inside of the vehicle. The window glass to be used is not particularly limited as long as it is a vehicle window glass, and can be installed in any of a windshield, rear window, side window, etc. Note that, for convenience of explanation, the following description will be made based on the directions indicated in each drawing, but these directions do not limit the present invention.

[0023] 1, the window glass (glass body) according to this embodiment includes a glass plate 100 and an antenna 10 disposed on the glass plate 100. Each component will be described below in order.

[0024] <1-1. Glass Plate> The glass plate 100 may be a known glass plate used as window glass for automobiles. For example, heat-absorbing glass, general clear glass or green glass, or UV-green glass may be used as the glass plate 100. However, such a glass plate 100 must achieve a visible light transmittance that complies with the safety standards of the country in which the automobile is used. For example, the solar absorptance, visible light transmittance, etc. can be adjusted to satisfy the safety standards. An example of the composition of clear glass and an example of the composition of heat-absorbing glass are shown below.

[0025] (Clear glass) SiO2: 70 to 73 mass% Al2O3: 0.6 to 2.4 mass% CaO: 7 to 12 mass% MgO: 1.0 to 4.5 mass% R2O: 13 to 15 mass% (R is an alkali metal) Total iron oxide (T-Fe2O3) converted to Fe2O3: 0.08 to 0.14 mass%

[0026] (Heat-ray absorbing glass) The composition of the heat-ray absorbing glass can be, for example, based on the composition of clear glass, such that the ratio of total iron oxide (T-Fe2O3) converted to Fe2O3 is 0.4 to 1.3 mass%, the ratio of CeO2 is 0 to 2 mass%, and the ratio of TiO2 is 0 to 0.5 mass%, and the amount of glass framework components (mainly SiO2 and Al2O3) is reduced by the amount of increase in T-Fe2O3, CeO2, and TiO2.

[0027] The type of the glass plate 100 is not limited to clear glass or heat-absorbing glass, and may be appropriately selected depending on the embodiment. For example, the glass plate 100 may be a resin window such as an acrylic or polycarbonate resin.

[0028] Furthermore, such glass plate 100 may be formed of a single glass plate, or may be laminated glass in which an interlayer film such as a resin is sandwiched between multiple glass plates. When the window glass is a single glass plate, the antenna is disposed on the interior surface of the window glass. On the other hand, when the window glass is laminated glass, the antenna 10 may be disposed on the interior surface of the glass plate 100 on the interior side of the vehicle, or the antenna 10 may be disposed between two glass plates.

[0029] <1-2. Antenna> Figure 2 is a front view of the antenna, as seen from the window glass from inside the vehicle. The following description will be given according to the directions shown in each figure, but these directions are merely examples, and the antenna according to the present invention can be configured in a way that is not limited to these directions.

[0030] The antenna 10 according to this embodiment includes a first power supply 1, a second power supply 2, a first element 3, a second element 4, and a third element 5. Each of the elements 3 to 5 is linearly formed. The first power supply 1 and the second power supply 2 are rectangularly formed and arranged at a predetermined interval in the horizontal direction. In this embodiment, the first power supply 1 is arranged on the left side. These power supply 1 and 2 are connected to connection terminals (not shown) provided inside the vehicle and are connected to an amplifier (not shown) for receiving broadcast waves via a coaxial cable (not shown). In this embodiment, the first power supply 1 is connected to the inner conductor (HOT) of the coaxial cable, and the second power supply 2 is connected to the outer conductor (GND) of the coaxial cable. As will be described later, when the antenna 10 is used for ITS, the coaxial cable is connected to an ITS transceiver (not shown) provided inside the vehicle.

[0031] In the following description, the wavelength shortening rate of the glass plate 100 is κ, and the wavelength of the center frequency of the frequency range in which the antenna transmits and receives is λ. The wavelength shortening rate κ of the glass plate 100 varies depending on the composition, thickness, etc. of the glass plate, but is, for example, about 0.5 to 0.7. In this embodiment, a representative wavelength shortening rate κ may be 0.65.

[0032] <1-2-1. First Element> As shown in FIG. 2 , the first element 3 includes linear first to sixth sections 31 to 36. The first section 31 extends substantially horizontally from the lower right corner of the second power supply section 2 to the right side (the side opposite the first power supply section). The second section 32 extends substantially vertically downward from the tip of the first section 31. The third section 33 extends substantially horizontally from the tip of the second section 32 to the left side (toward the first power supply section 1). The fourth section 34 extends downward from the left end of the third section 33, and the fifth section 35 extends left from the lower end of the fourth section 34. The sixth section 36 extends upward from the left end of the fifth section and is connected to the lower right corner of the first power supply section 1. That is, the first element 3 extends in a loop shape between the first power supply section 1 and the second power supply section 2. The lower end of the sixth portion 36 is the boundary with the first portion 51 of the third element 5, which will be described later, and is therefore sometimes referred to as a connection point C1.

[0033] The overall length of the first element 3 can be, for example, 3 / 16κλ to 10 / 16κλ, which enables reception of broadcast waves (radio waves) for DAB (Digital Audio Broadcasting: Band 3 174-240 MHz), DTV (Digital Television: 470-710 MHz), and Japan's ITS (Intelligence Transport System: 755-765 MHz), as will be described later.

[0034] The first element 3 may be provided with a linear extension portion having an open end and extending in one direction. As shown in Fig. 2, the fourth portion 34 is provided at its lower end with a first extension portion 71 extending substantially horizontally to the right, and the third portion 33 is provided at its left end with a second extension portion 72 extending substantially horizontally to the left. Only one of the first and second extension portions 71, 72 may be provided.

[0035] Furthermore, the first element 3 may have any shape (main body) extending in a loop shape between the first power supply 1 and the second power supply 2. For example, the first element 3 may have a shape that combines at least one portion extending in a substantially horizontal direction (substantially left-right direction) and at least one portion extending in a substantially vertical direction (substantially up-down direction). For example, as shown in FIG. 3 , the third portion 33 may extend to the right and connect to the lower end of the sixth portion 36. Furthermore, the extension may have various forms. In the example of FIG. 3 , a third extension 73 may be provided that extends substantially horizontally from the middle of the second portion 32 to the left.

[0036] As shown in Fig. 4, a fourth extension portion 74 may be provided that extends substantially horizontally to the right from the middle of the second portion 32. Also, as shown in Fig. 5, a fifth extension portion 75 may be provided that extends substantially horizontally to the right from the right end of the first portion 31, and a sixth extension portion 76 may be provided that extends substantially horizontally to the right from the bottom end of the second portion 32. Note that only one of the fifth and sixth extension portions 75, 76 may be provided.

[0037] As described above, the shape of the first element 3 is not particularly limited, as long as it extends in a loop shape between the first power supply 1 and the second power supply 2. In other words, the number, shape, position, and direction of the portions constituting the first element 3 are not particularly limited. Therefore, at least one portion may be curved. Furthermore, the direction of each portion may be not only horizontal or vertical, but also diagonal. Furthermore, the number, position, shape, and direction of the extending portions are not particularly limited, as long as they are provided at any position on the first element 3. Therefore, the extending portions may be provided so as to extend in a substantially vertical or diagonal direction. The embodiments described above in FIGS. 2 to 5 can be combined as appropriate, but are not limited to this.

[0038] The present inventors have confirmed that it is preferable to provide the extensions at positions away from the second power supply 2. For example, in the example shown in Fig. 5, when only one of the fifth extension 75 and the sixth extension 76 is provided, the inventors have confirmed that the length from the second power supply 2 to the tip of the extensions 75, 76 acts as an impedance adjustment factor, and that the sixth extension 76 has a higher antenna gain.

[0039] Furthermore, the extension portion is not necessarily required, and the first element 3 may have no extension portion.

[0040] 2, the second element 4 includes first to fourth sections 41 to 44. The first section 41 extends downward in a substantially vertical direction from the lower end of the sixth section 36 of the first element 3, and the second section 42 extends substantially horizontally from the tip of the first section 41 to the right (the opposite side from a third element 5, which will be described later). The third section 43 extends downward in a substantially vertical direction from the right end of the second section 42, and the fourth section 44 extends substantially horizontally from the lower end of the third section 43 to the left.

[0041] The total length of the second element 4 can be set, for example, as follows depending on the broadcast wave to be received: DAB: 3 / 16κλ to 3 / 8κλ (preferably 1 / 4κλ to 3 / 8κλ) DTV: 1 / 2κλ to 9 / 8κλ (preferably 3 / 4κλ to 9 / 8κλ) ITS: 1 / 4κλ to 3 / 8κλ

[0042] If the overall length of the second element 4 is set as described above, it is possible to not provide the fourth section 44, for example, as shown in Fig. 6. That is, the fourth section 44 is not necessarily required, but if the fourth section 44 is provided, the length of the third section 43 can be set to 5 mm or more.

[0043] As shown in FIG. 7, a fifth section 45 may be provided extending leftward from the lower end of the first section 41 .

[0044] The above-described configuration of the second element 4 is merely an example, and the number, shape, position, and direction of the portions constituting the second element 4 are not particularly limited, and the second element 4 may have a shape other than a linear shape. Therefore, at least one portion may be configured by a curve. Furthermore, the direction of each portion may extend not only horizontally or vertically, but also diagonally.

[0045] The distance D between the connection point C1 and the lower end of the first portion 41 can be set to 30 mm or less, and is preferably set to 10 mm or less. However, in consideration of the visibility (design) of the antenna, it is more preferable that the distance be set to 5 to 6 mm.

[0046] 2, the third element 5 includes first to third sections 51 to 53 extending linearly. The first section 51 extends substantially horizontally from the upper left corner of the first power supply section 1 to the left (opposite the second power supply section 2), and the second section 52 extends substantially vertically (up and down) downward from the tip of the first section 51. The third section 53 extends from the bottom end of the second section 52 to the right. The third section 53 is formed shorter than the first section 51.

[0047] The overall length of the third element 5 can be set, for example, as follows depending on the broadcast wave to be received: DAB: 0κλ to 2 / 10κλ (preferably 0 to 1 / 10κλ) DTV: 0κλ to 4 / 8κλ (preferably 0 to 3 / 10κλ) ITS: 1 / 4κλ to 1 / 2κλ Therefore, for DAB and DTV, proper reception is possible even without providing the third element 5.

[0048] For example, as shown in Fig. 6, the third element 5 may be formed of only the first portion 51, or may be formed of only the first portion 51 and the second portion 52. However, even in these cases, it is preferable to set the overall length of the third element 5 as described above. Furthermore, when the third portion 53 is provided, the length of the second portion 52 may be set to 1 / 12κλ to 3 / 32κλ.

[0049] The above-described configuration of the third element 5 is merely an example, and the number, shape, position, and direction of the portions constituting the third element 5 are not particularly limited, and the third element 5 may have a shape other than a linear shape. Therefore, at least one portion may be configured by a curve. Furthermore, the direction of each portion may extend not only horizontally or vertically, but also diagonally.

[0050] The above-described configurations of the first to third elements 3 to 5 can be combined as appropriate.

[0051] 8, a fourth element 6 may be provided that extends substantially horizontally to the right from the second power supply 2. The position of the fourth element 6 is not particularly limited, as long as it extends from any part of the second power supply 2. The number, shape, position, and direction of the fourth elements 6 are also not particularly limited, and the fourth elements 6 may have a shape other than a straight line. Therefore, the fourth element 6 may be configured with multiple parts, like the first to third elements 3 to 5.

[0052] <1-4. Antenna Material> The material forming each element of the antenna 10 may be any material as long as it has electrical conductivity, and examples thereof include silver, gold, platinum, etc. Specifically, the antenna 10 can be formed by printing and baking a conductive silver paste containing silver powder, glass frit, etc. on the surface of the glass plate 100. When the glass plate 100 is laminated glass, the antenna 10 can be formed on the interior surface of the outer glass plate, the exterior surface of the inner glass plate, or the interior surface of the inner glass plate.

[0053] <1-5. Function of Antenna> The antenna 10 can be used to receive various broadcast waves such as the above-mentioned DTV and DAB.

[0054] Furthermore, the antenna 10 can also be used as an ITS antenna for transmitting and receiving radio waves. For example, in Japan, in order to receive other vehicle information and roadside equipment information and to transmit vehicle information, the antenna is adjusted so that the average antenna gain of vertically polarized waves in a predetermined horizontal plane is equal to or greater than a predetermined value in the 755-765 MHz range (hereinafter referred to as "functional requirement"). Furthermore, to prevent interference with nearby radio waves in other frequency bands, the antenna is adjusted so that the maximum gain over the entire sky is equal to or less than 0 dBi (based on Article 49-22-2 of the Radio Equipment Regulations of the Ministry of Internal Affairs and Communications, hereinafter referred to as "legal requirement").

[0055] When used as an antenna for ITS, the first element 3 and the second element 4 are used to adjust the average gain of vertically polarized waves in a predetermined horizontal plane and to suppress unwanted components that are not used for communication but mainly act as interfering elements, while the third element 5 is mainly used to adjust the antenna performance to a predetermined frequency.

[0056] 2. Features The window glass configured as above can provide the following effects.

[0057] (1) In addition to the first element 3 formed in a loop shape, by providing the second element 4 and the third element 5 connected to the first element 3, the reception performance of the antenna can be improved.

[0058] (2) By providing the extension portion on the first element 3, it is possible to adjust the antenna performance to a predetermined frequency without significantly changing the element length of the first element 3 between the first feed 1 and the second feed 2. For example, if an attempt is made to increase the overall length of the first element 3 without providing the extension portion, the area occupied by the first element 3 would increase, which may reduce the degree of freedom in antenna design. In contrast, by providing the extension portion, it is possible to adjust the antenna length while keeping the area occupied by the first element 3 small. This makes it possible, for example, to obtain reception performance equivalent to that of an antenna with a large area occupied by the first element 3 while keeping the area occupied by the first element 3 small.

[0059] Furthermore, the antenna performance can be adjusted by adjusting only the length of at least one of the extension portions without changing the length of each portion of the first element 3, so that the antenna performance can be easily adjusted.

[0060] Furthermore, by moving the fourth section 34 horizontally and changing its position, the relative lengths of the extensions 71, 72 can be changed. For example, moving the fourth section 34 to the right shortens the first extension 71 and lengthens the second extension 72. Therefore, not only can the lengths of the first extension 71 and the second extension 72 be adjusted independently, but by changing the position of the fourth section 34, the ratio between the lengths of the first extension 71 and the second extension 72 can be changed, thereby adjusting the reception performance of the antenna.

[0061] (3) By having the first to third elements 3 to 5, the antenna 10 can satisfy both the above-mentioned functional requirements and legal requirements in transmitting and receiving ITS radio waves.

[0062] 3. Modifications Although one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and various modifications are possible without departing from the spirit of the present invention. Note that the following modifications can be combined as appropriate, and the modifications can also be combined with the above embodiment.

[0063] (1) In the above embodiment, the antenna includes first to third elements 3 to 5. However, the antenna can be configured with only the first element 3 and the second element 4 without providing the third element 5. That is, for example, the antenna can be configured as shown in FIGS. 9 and 10. Even in such a configuration, the effect described in the above-mentioned feature (1) can be obtained. Furthermore, an extension portion can be provided in the example of FIGS. 9 and 10. The configuration of the first element 3 and the second element 4 is not particularly limited, as shown in the above embodiment.

[0064] (2) The shape of the power supply portions 1 and 2 is not particularly limited, and may be other than rectangular.

[0065] (3) The same results can be obtained even if the antennas described above are reversed.

[0066] (4) In the above embodiment, the first to third elements are required when the antenna is used for an ITS. However, the frequency of the radio waves transmitted and received is not limited to this, and the antenna can be used in countries other than Japan. Furthermore, this antenna can be used in other two-way communication systems for vehicles other than ITS. Therefore, even if a frequency other than 755 to 765 MHz, such as that used in Japan's ITS, is used, an antenna that satisfies regulatory and functional requirements can be constructed by setting the length of the elements based on κλ. Furthermore, while the regulatory requirement is exemplified by a maximum gain of 0 dBi, it may be adjusted to be, for example, 0 dBi or less.

[0067] Examples of the present invention will be described below, but the present invention is not limited to the following examples.

[0068] <1. Overview> The performance of the antenna described in the above embodiment will be examined below. In examining the reception performance below, three-dimensional electromagnetic field simulation software was used to examine the reception performance of DAB, DTV, and ITS. In this simulation, a typical laminated glass with a thickness of 7 mm was assumed, and the glass plate was modeled. The antenna line width was also assumed to be 1 mm, and the wavelength shortening rate κ of the surface of the glass plate was assumed to be 0.65. The simulation procedure was as follows: (1) the vehicle, antenna, etc. were modeled and materials were set; and (2) appropriate meshes were set for the vehicle, antenna, etc., and then the simulation was performed. The setup and execution of such simulations are common to the examination of the examples and comparative examples described below.

[0069] <2. Models Considered> As examples, simulations for DAB, DTV, and ITS were performed using the models shown below. Models 1 to 3 shown in Table 1 are models with extended portions, as shown in Figures 11 to 13, and Models 4 to 6 shown in Table 2 are models without extended portions, as shown in Figures 14 to 16. However, the dimensions shown in Tables 1 and 2 below are the basic dimensions of each model, and if simulations are performed with different dimensions, this will be explained separately.

[0070]

[0071] <3. Study Method> Below, we performed a simulation of the reception performance of DAB, DTV, and ITS for each of the above models. (1) Reception performance Vertical polarization Average value of gain in the 0 degree elevation angle range (2) Received radio waves DAB: Frequency 174-240 MHz, center frequency 205 MHz (wavelength in vacuum λ = 1463 mm, κλ = 951 mm) DTV: Frequency 470-710 MHz, center frequency 590 MHz (wavelength in vacuum λ = 508 mm, κλ = 330 mm) ITS: Frequency is 760 MHz (wavelength in vacuum λ = 394 mm, κλ = 256 mm)

[0072] <4. Results> (1) DAB Reception Performance 1 In Model 1, the overall length of the third element was changed in the range of 0 to 120 mm, and a simulation was performed on the reception performance. The results are shown in Figure 17. A reception performance of -12 dBd or higher is considered preferable, but -15 dBd or higher is practical.

[0073] As shown in Figure 18, the frequency range of DAB Band 3 is 174 to 240 MHz, and the receiver exhibits reception performance that is practically acceptable in this frequency range. Furthermore, even when the length of the third element is 0 mm, i.e., when the third element is not present, the receiver exhibits good reception performance in the above frequency range. Therefore, it was found that the third element is not essential for DAB reception.

[0074] Furthermore, in Model 1, the total length of the second element was changed in the range of 220 to 370 mm, and a simulation was performed on the reception performance. The results are shown in Fig. 18. As shown in Fig. 18, it was found that the total length of the second element is preferably in the range of 240 to 370 mm in the above frequency range.

[0075] (2) DAB Reception Performance 2 In Model 4, the length of the first portion of the first element was varied between 70 mm and 120 mm (hereinafter referred to as Model 4 (70 mm) and Model 4 (120 mm)), and a simulation of reception performance was performed. For comparison, a simulation was also performed for Model 1 (where the length of the first portion of the first element was 70 mm) shown in Table 1. The results are shown in FIG. 19. As shown in FIG. 19, when comparing Model 4 (70 mm) and Model 4 (120 mm), Model 4 (120 mm) exhibited higher reception performance. In contrast, Model 1, which includes an extension, exhibited reception performance equivalent to that of Model 4 (120 mm). That is, even if the length of the first portion of the first element is shorter than that of Model 4 (120 mm), as in Model 1, providing an extension allows for reception performance equivalent to that of Model 4 (120 mm). Therefore, it was found that Model 1 can improve reception performance while reducing the area occupied by the first element compared to Model 4 (120 mm).

[0076] (3) DTV Reception Performance 1 In Model 2, the overall length of the third element was changed in the range of 0 to 140 mm, and a simulation was conducted on the reception performance. The results are shown in Figure 20. A reception performance of -10 dBd or higher is considered preferable, but -12 dBd or higher is practical.

[0077] As shown in Figure 20, when the length of the third element is 0 to 120 mm, reception performance is practically satisfactory in the DTV frequency range (470 to 710 MHz). Furthermore, when the length of the third element is 0 mm, i.e., when there is no third element, good reception performance is obtained in almost all frequency ranges. Therefore, it was found that the third element is not essential for DTV reception.

[0078] Furthermore, in Model 2, the total length of the second element was changed in the range of 170 to 410 mm, and a simulation was performed on the reception performance. The results are shown in Fig. 21. As shown in Fig. 21, it was found that the reception performance of Model 2 was generally good across the entire DTV frequency range when the total length of the second element was in the range of 170 to 410 mm.

[0079] (4) DTV Reception Performance 2 In Model 5, the length of the first portion of the first element was varied between 50 and 70 mm (hereinafter referred to as Model 5 (50 mm) and Model 5 (70 mm)), and a simulation of reception performance was performed. For comparison, Model 2 (where the length of the first portion of the first element was 50 mm) shown in Table 1 was also simulated. The results are shown in FIG. 22. As shown in FIG. 22, when Model 5 (50 mm) is compared with Model 5 (70 mm), Model 5 (70 mm) generally exhibits higher reception performance. In contrast, Model 2, which includes an extension, exhibits reception performance equivalent to that of Model 5 (70 mm). That is, even if the length of the first portion of the first element is shorter than that of Model 5 (70 mm), providing an extension can achieve reception performance equivalent to that of Model 5 (70 mm). Therefore, it was found that Model 2 can improve reception performance while reducing the area occupied by the first element compared to Model 5 (70 mm).

[0080] (5) ITS Reception Performance 1: A simulation was conducted on the reception performance of Model 3 by varying the length of the first extension portion between 0 mm, 25 mm, and 35 mm. The results are shown in Figure 23. A reception performance of -7 dBi or higher is considered desirable, but a reception performance of -10 dBi or higher is practical. As shown in Figure 23, when the length of the first extension portion was 35 mm, the reception performance was highest in the 754 to 766 MHz range, which is the frequency range used by ITS in Japan. When the first extension portion was absent or 25 mm, the reception performance was roughly equivalent in the 754 to 766 MHz range.

[0081] (6) ITS Reception Performance 2 In Model 6, the length of the first portion of the first element was changed between 20 and 50 mm, and a simulation was performed to evaluate the reception performance. The results are shown in Figure 24. As shown in Figure 24, the reception performance of the ITS was highest when the length of the first portion of the first element was 42.5 mm. Furthermore, the reception performance was lowest when the length of the first portion was 50 mm, and the reception performance decreased as the length decreased from 42.5 mm.

[0082] Comparing the cases where the length of the first portion of the first element in Model 3 is 35 mm with that in Model 6, it was found that the reception performance can be improved depending on the length of the extension portion, as shown in Figure 23. Therefore, it was found that the reception performance can be adjusted by the extension portion.

[0083] As a comparative example, the above-described DAB reception simulation was also performed on an antenna using only the first element in Model 4 of FIG. 14 (an antenna composed only of a loop-shaped element). However, the length of the first portion of the first element was set to 130 mm. Furthermore, as a comparative example, Model 4 of FIG. 14 was used, and the length of the first portion of the first element was set to 130 mm, as in the comparative example. The results are shown in FIG. 25. As shown in the figure, the antenna of the comparative example had reception performance of -15 dBd or less in many frequency ranges. In other words, it was found that the frequency width suitable for reception was narrow, making it unsuitable as an antenna for receiving a wide frequency band such as DAB. This point was also true for DTV, although not shown. Therefore, by adding other elements to the loop-shaped element as in each of the above examples, it is possible to form an antenna with a wide reception band and in which the loop-shaped portion (first element) can be used as an adjustment element for frequency characteristics.

[0084] 100 Glass plate 10 Antenna 1 First feeding section 2 Second feeding section 3 First element 4 Second element 5 Third element

Claims

1. A glass body for a vehicle comprising: a glass sheet; a first power supply portion arranged on the glass sheet; a second power supply portion arranged on the glass sheet and horizontally spaced from the first power supply portion; and an antenna arranged on the glass sheet and connected to the first power supply portion and the second power supply portion, wherein the antenna comprises: a first element having a body portion connecting the first power supply portion and the second power supply portion; and a second element connected to the first element.

2. The glass body according to claim 1, wherein the first element is configured such that the main body portion is formed by combining a plurality of portions extending substantially horizontally and a plurality of portions extending substantially vertically.

3. The glass body according to claim 1 or 2, comprising at least one linear extension portion that is connected to any one of the main body portions of the first element and has an open end and extends in one direction.

4. The glass body according to claim 3, wherein the main body portion is constructed by combining a plurality of substantially horizontally extending portions and a plurality of substantially vertically extending portions, and the extension portions are connected to the intersections of the substantially horizontally extending portions and the substantially vertically extending portions in the main body portion.

5. The glass body according to claim 3 or 4, wherein the extension portion extends substantially horizontally.

6. The glass body according to claim 1 or 2, wherein the second element is configured by combining at least one portion extending substantially horizontally and at least one portion extending substantially vertically.

7. The glass body according to claim 1 or 2, wherein the second element is connected to a lower portion of the first element.

8. The glass body according to claim 1 or 2, wherein the length of the first element is 3 / 16κλ to 10 / 16κλ, where λ is the wavelength of the center frequency of the frequency band received by the antenna and κ is the wavelength shortening rate of the glass plate.

9. The glass body according to claim 1 or 2, wherein the antenna is configured to receive a DTV frequency band.

10. The glass body according to claim 9, wherein the length of the second element is between 3 / 16 κλ and 3 / 8 κλ.

11. The glass body of claim 1 or 2, wherein the antenna is configured to receive a DAB frequency band.

12. The glass body of claim 11, wherein the length of the second element is between 1 / 2 κλ and 9 / 8 κλ.

13. The glass body of claim 1 or 2, wherein the antenna further comprises a third element connected to the first feed portion.

14. The glass body according to claim 13, wherein the third element has at least a portion extending on a side opposite the second power supply portion.

15. The glass body according to claim 13 or 14, wherein the antenna is configured to transmit and receive ITS radio waves.