Glass antenna

Abstract

The present invention is a glass antenna provided to window glass in a vehicle and comprising a hot part, a ground part, and an antenna main body that is connected to the hot part and the ground part, wherein the frequency band is configured so as to able to receive 600 Mhz to 5 Ghz radio waves.

Description

Technical Field

[0001] The present invention relates to a glass antenna provided on a window glass of a vehicle.

Background Art

[0002] An antenna that transmits and receives radio waves over a wide band has a planar shape in order to resonate at various frequencies. (For example, Patent Document 1). By the way, the current communication technology for automobiles is shifting from the fourth-generation communication (4G) to the fifth-generation communication (5G). Therefore, in automobiles as well, there is a need for a vehicle glass antenna that can receive radio waves in the 5G frequency band.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, even when 5G is introduced, communication in the 4G frequency band is also used in combination. Therefore, in a vehicle that moves regardless of the area of 4G and 5G, it is necessary to be able to receive radio waves in both the 4G and 5G frequency bands. Therefore, it is necessary to equip the vehicle with an antenna that supports both 4G and 5G. However, so far, there has been no glass antenna that can receive radio waves corresponding to both the 4G and 5G frequency bands, and such a glass antenna has been desired. The present invention has been made to solve this problem, and an object thereof is to provide a glass antenna capable of receiving radio waves in frequency bands corresponding to both 4G and 5G.

Means for Solving the Problems

[0005] Item 1. A glass antenna provided on a window glass of a vehicle, A hot part, a ground part, and an antenna body connected to the hot part and the ground part, are provided, a glass antenna configured to receive radio waves in a frequency band of 600 MHz to 5 GHz.

[0006] Item 2. The antenna body is, a first part formed in a planar shape, a second part formed in a planar shape and electrically connected to the first part, The glass antenna according to Item 1, comprising.

[0007] Item 3. At least one of the outer edges of the first part and the second part has at least one corner. The glass antenna according to Item 2.

[0008] Item 4. At least one of the first part and the second part is formed by a polygon with straight sides. The glass antenna according to Item 2.

[0009] Item 5. The ground part is disposed near a portion of the outer peripheral edge of the first part that is farthest from the second part. The glass antenna according to any one of Items 2 to 4.

[0010] Item 6. When the wavelength of the radio wave is λ and the wavelength shortening rate in the window glass is α, the distance from the hot part to the second part is α×λ / 20 or more. The glass antenna according to Item 5.

[0011] Item 7. The first part is larger than the second part. The glass antenna according to Item 5 or 6.

[0012] Item 8. The first part and the second part pass through the ground part and are formed symmetrically with respect to a reference line passing through the first part and the second part. The glass antenna according to any one of Items 5 to 7.

[0013] Item 9. The glass antenna according to any one of Items 2 to 4, wherein one vertex of the outer peripheral edge of the first part and one vertex of the outer peripheral edge of the second part are arranged to face each other.

[0014] Item 10. The glass antenna according to Item 9, wherein the first part and the second part are formed in a symmetrical shape with respect to the midpoint between the one vertices of the respective parts.

[0015] Item 11. The glass antenna according to Item 9 or 10, wherein the hot part and the ground part are arranged outside the first part and the second part.

[0016] Item 12. A first line part extending so as to connect the ground part and the first part, A second line part extending in parallel with the first line part and extending so as to connect the hot part and the second part, The glass antenna according to Item 11, further comprising:

[0017] Item 13. The glass antenna according to Item 12, wherein the gap between the first line part and the second line part is 1 mm or less.

Advantages of the Invention

[0018] According to the glass antenna of the present invention, radio waves in frequency bands corresponding to both 4G and 5G can be received.

Brief Description of the Drawings

[0019]

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Figure 11A

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Figure 21

Mode for Carrying Out the Invention

[0020] Hereinafter, embodiments of the glass antenna according to the present invention will be described with reference to the drawings. FIG. 1 is a plan view showing a window glass of a vehicle in which a first glass antenna is disposed. The target window glass is not particularly limited as long as it is a window glass of a vehicle, and can be disposed on any of a windshield, a rear glass, a side glass, etc. In this embodiment, two types of glass antennas, that is, the first and second glass antennas 10 and 20 will be described. Although the first glass antenna 10 is shown in FIG. 1, at least one of the glass antennas 10 and 20 is disposed on the window glass. Hereinafter, first, the window glass 80 will be described, and then the glass antennas 10 and 20 will be described in detail.

[0021] <1. Glass plate> First, the window glass 80 on which the glass antennas 10 and 20 are disposed will be described. As the window glass 80, a known glass plate for automobiles can be used. For example, as the glass plate, a heat ray absorbing glass, a general clear glass, a dark privacy glass or green glass, or a UV green glass may be used. However, such a glass plate needs to achieve a visible light transmittance in accordance with the safety standards of the country where the automobile is used. For example, the solar radiation absorption rate, the visible light transmittance, etc. can be adjusted to meet the safety standards. Hereinafter, an example of the composition of clear glass and an example of the composition of heat ray absorbing glass are shown.

[0022] (Clear glass) SiO 2 : 70 to 73% by mass Al 2 O 3 : 0.6 to 2.4% by mass CaO: 7 to 12% by mass MgO: 1.0 to 4.5% by mass R 2 O: 13 to 15% by mass (R is an alkali metal) Fe 2 O 3 Converted to total iron oxide (T-Fe 2 O 3 ): 0.08 to 0.14% by mass

[0023] (Heat-absorbing glass) The composition of the heat-absorbing glass is, for example, based on the composition of clear glass, with the ratio of total iron oxide (T-Fe 2 O 3 ) converted to 0.4 to 1.3% by mass, the ratio of CeO 2 O 3 being 0 to 2% by mass, the ratio of TiO 2 being 0 to 0.5% by mass, and the glass skeletal components (mainly SiO 2 and Al 2 and Al 2 O 3 ) can be made into a composition reduced by the increments of T-Fe 2 O 3 , CeO 2 and TiO 2 .

[0024] Note that the type of the glass plate is not limited to clear glass or heat-absorbing glass and can be appropriately selected according to the embodiment. For example, the glass plate may be a resin window such as an acrylic-based or polycarbonate-based resin window.

[0025] Also, this window glass 80 is appropriately formed in a curved shape. And such a window glass 80 may be composed of a single glass plate, or may be a laminated glass in which an intermediate film such as resin is sandwiched between two glasses. When the window glass is a single glass plate, the glass antenna is disposed on the inner surface of the window glass 80 on the vehicle interior side. On the other hand, when the window glass 80 is laminated glass, in addition to disposing the glass antennas 10, 20 on the inner surface of the inner glass plate on the vehicle interior side, the glass antennas 10, 20 can also be disposed between the two glass plates.

[0026] <2. First Glass Antenna> Next, the first glass antenna 10 will be described with reference to FIG. 2. FIG. 2 is a plan view showing the first glass antenna. The first glass antenna 10 includes an antenna body having a first portion 11 and a second portion 12 disposed on the inner surface of the window glass 80 on the vehicle interior side, and a line portion 13, and these are formed in a sheet shape from a conductive material. Further, a ground portion 5 is provided in the first portion 11, and a hot portion 6 is provided in the line portion 13. These ground portion 5 and hot portion 6 are connected to a receiver (not shown) provided in the vehicle interior by a coaxial cable (not shown). Hereinafter, for convenience of explanation, the description will be made according to the first direction and the second direction orthogonal thereto shown in FIG. 2. However, in the example of FIG. 2, the first direction is the horizontal direction and the second direction is the vertical direction, but the present invention is not limited to this, and these directions can be appropriately changed while maintaining the relationship between the first direction and the second direction. This also applies to the second glass antenna 20 described later.

[0027] <2-1. First Portion> The first portion 11 is formed in a substantially pentagonal shape that is symmetric about the left and right, and includes a first side 111 extending in the first direction, a second side 112 and a third side 113 extending upward orthogonally from both ends of the first side 111, and a fourth side 114 and a fifth side 115 extending obliquely from the upper ends of the second side 112 and the third side 113. The fourth side 114 and the fifth side 115 extend so as to approach each other as they go upward, and a rectangular protruding portion 116 is formed at a location where the upper end portions of the fourth side 114 and the fifth side 115 meet.

[0028] Further, a slit 117 is formed so as to extend in the second direction from inside the protruding portion 116, that is, from a position slightly below the upper edge of the protruding portion 116 to the first side 111. And the above-described circuit portion 13 is disposed in this slit. The circuit portion 13 is formed linearly and is disposed with a slight gap from the inner edge of the slit 117. And the lower end of the circuit portion 13 is connected to the second portion 12. Note that the length of the circuit portion 13, that is, the distance from the hot portion 6 to the second portion 12 is not particularly limited. However, in order to improve the reception performance, assuming that the wavelength of the received radio wave is λ and the wavelength shortening rate α in a general window glass is 0.6 to 0.7, for example, it is preferably α×λ / 20 (α is the wavelength shortening rate in the window glass) or more.

[0029] The above-described ground portion 5 is provided on the protruding portion 116, and the hot portion 6 is provided at the upper end of the circuit portion 13. Therefore, the ground portion 5 and the hot portion 6 are disposed with a gap therebetween via the slit 117.

[0030] <2-2. Second Portion> Next, the second portion 12 will be described. The second portion 12 is disposed below the first portion 11. The second portion 12 is formed in a bilaterally symmetric pentagonal shape (home base type), and includes a first side 121 extending in the first direction, a second side 122 and a third side 123 extending orthogonally upward from both ends of the first side 121, and a fourth side 124 and a fifth side 125 extending obliquely from the upper ends of the second side 122 and the third side 123. The fourth side 124 and the fifth side 125 extend so as to approach each other as they go upward. And the upper end portions of the fourth side 124 and the fifth side 125 are in contact with each other to form an upper vertex 126. The lower end of the above-described circuit portion 13 is connected to this upper vertex 126.

[0031] The second portion 12 is formed smaller than the first portion 11. For example, as shown in FIG. 2, the lengths of the second portion 12 in the first direction and the second direction can be each about half of the first portion 11.

[0032] As described above, the antenna body of the first glass antenna 10 is formed symmetrically with respect to a reference line (a line along the line portion 13) that passes through the ground portion 5 and extends in the vertical direction.

[0033] The size of the first glass antenna 10 is not particularly limited. For example, the length in the first direction is preferably 30 to 90 mm, and more preferably 40 to 80 mm. On the other hand, the length in the second direction is preferably 20 to 80 mm, and more preferably 30 to 70 mm. This is the same for the second glass antenna 20.

[0034] <3. Second Glass Antenna> Next, the second glass antenna 20 will be described with reference to FIG. 3. FIG. 3 is a plan view showing the second glass antenna. The second glass antenna 20 includes an antenna body having a first portion 21 and a second portion 22 disposed on the inner surface of the window glass 80, a first line portion 23, a second line portion 24, and an extending portion 26, which are formed in a sheet shape from a conductive material. Further, a ground portion 5 is provided on the first line portion 23, and a hot portion 6 is provided on the second line portion 24. These ground portion 5 and hot portion 6 are connected to a receiver provided in the vehicle by a coaxial cable, similar to the first glass antenna.

[0035] <3-1. First Portion> The first portion 21 is formed in a bilaterally symmetric pentagonal shape, and includes a first side 211 extending in the first direction, second sides 212 and 213 extending downward orthogonally from both ends of the first side 211, and fourth sides 214 and 215 extending obliquely from the lower ends of the second sides 212 and 213. The fourth sides 214 and 215 extend so as to approach each other downward. Then, the lower ends of the fourth sides 214 and 215 are in contact with each other, forming a lower vertex 216.

[0036] <3-2. Second Portion> The second part 22 is arranged below the first part 21 and is formed in a shape that is vertically symmetric with the first part 21. That is, the second part 22 is formed in a bilaterally symmetric pentagonal shape, and includes a first side 221 extending in the first direction, a second side 222 and a third side 223 extending orthogonally upward from both ends of the first side 221, and a fourth side 224 and a fifth side 225 extending obliquely from the upper ends of the second side 222 and the third side 223. The fourth side 224 and the fifth side 225 extend so as to approach each other as they go upward. And the upper ends of the fourth side 224 and the fifth side 225 are in contact with each other, forming an upper vertex 226. The upper vertex 226 and the lower vertex 216 of the first part 21 are arranged with a slight gap therebetween, and the first line part 23 and the second line part 24 are arranged in this gap.

[0037] <3-3. First Line Part and Second Line Part> The first line part 23 is arranged on the right side of the first part 21 and is formed in an L shape. That is, it has a first line section 231 extending in the vertical direction and a second line section 232 extending horizontally to the left from the lower end of the first line section 231. The upper end of the first line section 231 is at approximately the same vertical position as the first side 211 of the first part 21. Also, the lower end of the first line section 231 is at approximately the same vertical position as the lower vertex 216 of the first part 21. Therefore, the left end of the second line section 232 is connected to the lower vertex 216.

[0038] The second line portion 24 is also disposed on the right side of the first portion 21 and is formed in an L shape. That is, it has a first line portion 241 extending in the vertical direction and a second line portion 242 extending horizontally to the left from the lower end of the first line portion 241. The first line portion 241 is formed to have substantially the same length as the first line portion 231 of the first line portion 23 and extends in parallel with a gap on the right side of the first line portion 231. Similarly, the second line portion 242 is formed to have substantially the same length as the second line portion 232 of the first line portion 23 and extends in parallel with a gap below the second line portion 232. And the left end portion of the second line portion 242 is connected to the upper apex 226 of the second portion 22. The length of the gap between the first line portion 23 and the second line portion 24 is not particularly limited, but according to the inventor, in order to improve the reception performance, it is 1 mm or less, preferably 0.5 mm or less, and more preferably 0.1 mm or less. Note that the lengths of the line portions 23 and 24 can be set to α×λ / 20, similar to the first glass antenna 10.

[0039] Also, a ground portion 5 is provided at the upper end of the first line portion 231 of the first line portion 23, and a hot portion 6 is provided at the upper end of the first line portion 241 of the second line portion 24.

[0040] <3-4. Extending Portion> The extending portion 26 is disposed on the left side of the first portion 21 and is formed in an L shape. That is, the extending portion 26 includes a first line portion 261 extending in the vertical direction and a second line portion 262 extending horizontally to the right from the lower end of the first line portion 261. The upper end of the first line portion 261 is connected to the intersection of the second side 212 and the fourth side 214 of the first portion 21. Also, the right end portion of the second line portion 262 is connected to the left end portion of the first line portion 23.

[0041] <4. Material> The first glass antenna 10 and the second glass antenna 20 as described above can be formed by laminating a conductive material having conductivity on the surface of the window glass 80 so as to have a predetermined pattern. Such materials only need to have conductivity, and examples thereof include silver, gold, copper, platinum, ITO (indium tin oxide), and the like. Specifically, for example, it can be formed by printing and baking a conductive silver paste containing silver powder, glass frit, etc. on the surface of the window glass 80. In addition, a conductor that can be formed by directly depositing on the glass surface, such as ITO, can also be used. In the case of a material that can be formed into a foil shape, the foil can also be cut into a predetermined shape to form it. When the conductor is configured to be colored, in order to ensure visibility from inside the vehicle, for example, a sheet of a structure in which the conductor is made into thin wires and configured in a mesh shape can be cut, or it can be formed by directly printing on the window glass surface. Also, the thickness of each of the glass antennas 10 and 20 is not particularly limited, but can be, for example, 0.01 to 50 μm.

[0042] <5. Features> As described above, according to the glass antennas 10 and 20 according to the present embodiment, by providing two planar portions, good reception performance can be obtained in both the 4G and 5G frequency bands. More specifically, it is as follows.

[0043] The 4G and 5G frequency bands are assumed to be in the range of 600 MHz to 5 GHz. In a conventional linear antenna, since it can resonate only at a certain range of frequencies corresponding to the line segment length of the antenna, the receivable band can be at most several hundred MHz even if it is wide. Therefore, by forming an aggregate of antenna lines in which the line segment lengths are distributed in a certain range, that is, by making it planar, a line segment that resonates with radio waves occurs at any location within the plane over a wide band of several GHz, and thus good reception performance can be obtained.

[0044] As in the above-described first portions 11 and 21 and second portions 21 and 22, when the outer edge has corners, line segments where radio waves resonate, such as diagonal line segments starting from these corners, are likely to be generated. Further, when there are a plurality of these corners, radio wave resonance is likely to occur on the line segments connecting the respective corners, so that the reception performance can be further improved. Furthermore, since the first portions 11 and 21 and the second portions 21 and 22 are polygonal, radio wave resonance is also likely to occur on the straight sides, so that the reception performance can be further improved.

[0045] By setting the lengths of the line portions 13 and 24 from the hot portion 6 to be α×λ / 20 or more, the line portions 13 and 24 and the line portion 23 having substantially the same length as 24 can function as part of the impedance matching element, so that the reception performance can be made better.

[0046] Also, as in the second glass antenna 20, by making the first portion 21 and the second portion 22 have a symmetric shape, line segments where radio waves resonate are generated symmetrically, so that the reception performance can be made better.

[0047] For example, if the planar antenna of the present invention is constituted by a colored conductor, light is not transmitted only through that portion, which obstructs the view. Therefore, by constituting the antenna with a structure in which the thin wires of the conductor are formed in a mesh shape, it becomes possible for light to be partially transmitted, and it becomes possible to reduce the obstruction of the view. Using a transparent conductor is more preferable because there is no obstruction of the view.

[0048] <6. Modification Example> As described above, one embodiment of the present invention has been described, but the present invention is not limited to the above embodiment, and various modifications are possible without departing from the gist thereof. Note that the following modification examples can be combined as appropriate.

[0049] The shape of the glass antenna can be various and is not limited to the above embodiment. (1) The shapes of the first portions 11, 21 and the second portions 12, 22 of the respective glass antennas 10, 20 are not particularly limited, and in addition to polygonal shapes and circular shapes, they may be formed to have an outer edge in which straight lines and curves are mixed. For example, in the example of FIG. 4, in the first glass antenna 10, a part of the outer edge of the second portion 12 is formed by a curve. However, according to the inventor, in order to improve the reception performance, it is preferable that the outer peripheral edge of each portion is formed by a straight line and has at least one corner.

[0050] (2) The shape of the first glass antenna 10 in FIG. 2 is an example, and for example, as shown in FIG. 5, the width in the first direction can be narrowed, or the widths of the slit 117 and the circuit portion 13 can be widened. Also, as shown in FIG. 6, the width of the first portion 11 can be made more than twice the width of the second portion 12, and further, the width of the protruding portion 16 can be increased.

[0051] In the first glass antenna 10 described above, although the two portions are of different sizes, they may be of the same size. However, according to the inventor, in order to improve the reception performance, it is preferable that the first portion is larger than the second portion.

[0052] Also, in the first glass antenna 10 described above, the shape of the first portion 11 is substantially pentagonal, but it is not limited thereto, and other shapes may be used. For example, as shown in FIG. 7, the first portion 11 can be formed in a rectangular shape. The first portion 11 in this example is formed in a rectangular shape that is longer in the horizontal direction than in the vertical direction, and the length in the horizontal direction is longer than the length in the horizontal direction of the second portion 12.

[0053] Also, the shape of the second part 12 is not particularly limited and can be as shown in FIG. 8. In this example, the first part has the shape shown in FIG. 7, and the second part 12 is formed in a triangular shape. More specifically, in the example of FIG. 8, the second part 12 is formed in a substantially equilateral triangle shape, and a circuit part 13 is connected to the top vertex thereof. Further, a plurality of triangular through-holes are formed in the second part 12. Specifically, a first triangle 1201 is formed by connecting the midpoints of each side of the triangle constituting the second part 12, and this is used as the through-hole. Also, in the second part 12, in the three triangles formed above and to the left and right of the first triangle 1201, second triangles 1202 are respectively formed by connecting the midpoints of each side, and these are used as through-holes. Furthermore, in the second part 12, in the three triangles formed above and to the left and right of each second triangle 1202, third triangles 1203 are respectively formed by connecting the midpoints of each side, and these are used as through-holes. Thus, 13 through-holes in the shape of inverted triangles of three types are formed in the second part 12. In this example, the shape of the through-hole is an inverted triangle, but the shape of the through-hole is not particularly limited and can be various shapes such as a polygonal shape, a circular shape, and an irregular shape. Also, the position of the through-hole is not particularly limited.

[0054] (3) The shape of each part of the second glass antenna is not particularly limited. For example, as shown in FIG. 9, in each part 21, 22, the second sides 212, 222 and the third sides 213, 223 may be inclined obliquely. Also, as shown in FIG. 10, the extending part may not be provided. Also, the circuit parts 23, 24 can be formed in a straight line shape, and the shape of the circuit part is not particularly limited.

[0055] In the second glass antenna 20, although both parts have the same shape, they may have different shapes. However, according to the inventor, for improving the reception performance, it is preferable that the first part and the second part have the same size and are arranged to be point-symmetrical. Also, it is preferable that the tops of each part 21, 22 face each other, but it is not limited to this.

[0056] (4) As described above, in the first glass antenna 10, a slit 117 is provided in the first portion 11, and the circuit portion 13 is disposed in this slit 117. That is, the circuit portion 13 is disposed inside the first portion 11. On the other hand, in the second glass antenna 20, the circuit portions 23 and 24 are disposed outside both portions 21 and 22. However, as shown in the embodiments described later, it has been found that the shape and position of the circuit portion do not have a great influence on the reception performance, and thus the position and shape of the circuit portion are not particularly limited. Therefore, for example, the two circuit portions 23 and 24 in the second glass antenna 20 do not necessarily have to extend in parallel, and may be separated from each other. Also, the positions of the ground portion 5 and the hot portion 6 are not particularly limited, but it is preferable that they are close to each other.

[0057] (5) The orientation in which the glass antennas 10 and 20 are disposed on the window glass is not particularly limited, and they may be disposed in an appropriate orientation while considering the reception performance. Therefore, in addition to the orientation shown in FIG. 1, for example, as shown in FIG. 11A, it may be upside down with respect to FIG. 1, or as shown in FIG. 11B, it may be tilted by 90 degrees. Also, the positions where the respective glass antennas 10 and 20 are provided are not particularly limited, and they can be provided at any position on the window glass 80. FIG. 11C shows the second glass antenna 20 shown in FIG. 10 tilted by 90 degrees such that the circuit portions 23 and 24 are positioned upward. Thus, also for the second glass antenna 20, its rotation angle is not particularly limited.

[0058] (6) In the first glass antenna 10 of the above-described embodiment, the ground portion 5 is disposed at the vertex of the first portion 11 that is farthest from the second portion 12, but the position of the ground portion 5 is not particularly limited. That is, depending on the shape of the first portion 11, it is not limited to the vertex, and it may be disposed at the farthest portion such as a side and its vicinity.

Embodiment

[0059] Hereinafter, embodiments of the present invention will be described. However, the present invention is not limited to the following embodiments.

[0060] The reception performance of the glass antennas according to Examples 1 to 16 and the comparative example was examined below. In examining the reception performance, three-dimensional electromagnetic field simulation software was used. In this simulation, a general laminated glass in which a 0.76 mm interlayer film was sandwiched between two glass sheets with a thickness of 2.1 mm was assumed, and the glass plates were modeled. Further, the shape and dimensions of each glass antenna were as shown in Table 1 below, and a model assuming a shrinkage rate α of the glass plate of 0.61 and radio waves with a frequency of 500 MHz to 6 GHz was used. As the simulation procedure, (1) the vehicle, dielectric, antenna, etc. were modeled and the materials were set, and (2) appropriate mesh settings were made for the vehicle, dielectric, antenna, etc., and then the simulation was executed.

[0061] As shown in FIG. 12, the glass antenna according to the comparative example has a rectangular main body portion 71 and a linear line portion 72 extending upward from near the upper side of the main body portion 71. A gap is formed between the main body portion 71 and the line portion 72. Further, a hot portion 6 is disposed at the lower end of the line portion 72, and a ground portion 5 is disposed at a portion of the upper side of the main body portion 71 facing the line portion 72. Further, Examples 1 to 4 were formed as follows.

Table 1

[0062] Simulations were performed using Examples 1 to 4 and Comparative Examples configured as described above, and the results shown in FIG. 13 were obtained. FIG. 13 is a graph showing the reception performance at frequencies from 500 MHz to 6 GHz. According to the present inventor, if a return loss of -7.4 dB or less is obtained, it is considered practical. From FIG. 13, it was found that the comparative example obtained good return loss in the 5G frequency band, but the return loss was quite poor in the 4G frequency band. Examples 1 to 4 generally obtained good return loss in both the 4G and 5G frequency bands. Therefore, it was found that by providing two planar parts as in Examples 1 to 4, good return loss can be obtained in both the 4G and 5G frequency bands. On the other hand, in the shape of the comparative example as shown in FIG. 12, since the resonance frequency has a certain peak, good resonance characteristics cannot be obtained over a wide band.

[0063] Comparing Examples 1 and 2, in Example 2, the length in the second direction is approximately the same as that in Example 1, but the length in the first direction is about 2 / 3. However, there was not much difference in the reception performance due to this difference in size. Also, comparing Examples 1 and 3, mainly the position and shape of the line part are different. As a result, the overall reception performance does not change significantly, but the frequencies with high reception performance are different. For example, in Example 1, among the 5G frequency bands, the reception performance is high around 4 GHz, while in Example 3, the reception performance is high around 4.5 GHz. Also, comparing Examples 1 and 4, in Example 4, the lengths in both the first direction and the second direction are shorter than those in Example 1. As a result, it was found that Example 4 has lower overall reception performance than Example 1 in both the 4G and 5G frequency bands.

[0064] Next, Examples 5 to 15 will be examined. Examples 5 to 15 are antennas having the shape shown in FIG. 14, corresponding to the glass antenna shown in FIG. 7 described above. The antenna having the dimensions shown in FIG. 14 is the antenna according to Example 5. As shown in Table 2 below, Examples 6 to 15 are those in which the dimensions A to D (unit: mm) and the angle E (unit: °) in FIG. 14 are changed.

Table 2

[0065] For Examples 5 to 15 above, the reception performance of the antenna was calculated in the same manner as in Examples 1 to 4. The results are as shown in FIGS. 15 to 19. The glass antennas having the shapes shown in Examples 5 to 15 generally obtained a return loss of -7.4 dB or less (reference value in FIGS. 15 to 19) as described above, and it was found that they can withstand practical use.

[0066] Subsequently, Example 16 is considered. Example 16 is an antenna having the shape shown in FIG. 20, and corresponds to the glass antenna shown in FIG. 8 described above (the unit of the numerical values in the figure is mm). For this Example 16, the reception performance of the antenna was calculated in the same manner as in Examples 1 to 4. The results are as shown in FIG. 21. FIG. 21 has the frequency (GHz) on the horizontal axis and the return loss (dB) on the vertical axis. As shown in the figure, the glass antenna having the shape shown in Example 16 obtained a return loss of -7.4 dB or less (reference value in FIG. 21) in the range of 1.0 to 7.0 GHz, and it was found that it can withstand practical use.

Explanation of Signs

[0067] 11, 21 First part 12, 22 Second part 13 Line part 23 First line part 24 Second line part 5 Ground part 6 Hot part 10, 20 Glass antenna 80 Window glass

Claims

1. A glass antenna provided on a window glass of a vehicle, comprising: a hot part; a ground part; an antenna body connected to the hot part and the ground part; configured to receive radio waves in a frequency band of 600 MHz to 5 GHz, wherein the antenna body includes: a first part formed in a planar shape and electrically connected to the ground part; a second part formed in a planar shape and electrically connected to the hot part; and the ground part is disposed near a portion of the outer peripheral edge of the first part that is farthest from the second part.

2. The glass antenna according to claim 1, wherein at least one of the outer edges of the first part and the second part has at least one corner.

3. The glass antenna according to claim 1, wherein at least one of the first part and the second part is formed by a polygon with straight sides.

4. When the wavelength of the radio wave is λ and the wavelength shortening rate in the window glass is α, the distance from the hot part to the second part is α×λ / 20 or more. The glass antenna according to any one of claims 1 to 3.

5. The glass antenna according to any one of claims 1 to 4, wherein the first part is larger than the second part.

6. When a straight reference line passing through the ground part is defined, the first part and the second part are formed symmetrically with respect to the reference line. The glass antenna according to any one of claims 1 to 5.

7. A glass antenna provided on a window glass of a vehicle, comprising: a hot part; a ground part; an antenna body connected to the hot part and the ground part; configured to receive radio waves in a frequency band of 600 MHz to 5 GHz, wherein the antenna body includes: a first part formed in a planar shape and electrically connected to the ground part; a second part formed in a planar shape and electrically connected to the hot part; the first part and the second part are formed in a shape having a plurality of vertices on the outer peripheral edge, and one vertex of the outer peripheral edge of the first part and one vertex of the outer peripheral edge of the second part are arranged to face each other.

8. The glass antenna according to claim 7, wherein the first part and the second part are formed in a symmetric shape with respect to the midpoint between the one vertices of the respective parts.

9. The glass antenna according to claim 7 or 8, wherein the hot portion and the ground portion are disposed outside the first portion and the second portion.

10. A first line portion extending so as to connect the ground portion and the first portion; A second line portion extending in parallel with the first line portion and extending so as to connect the hot portion and the second portion; The glass antenna according to claim 9, further comprising:

11. The glass antenna according to claim 10, wherein a gap between the first line portion and the second line portion is 1 mm or less.

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