JP2022016800A - Vehicle window glass - Google Patents

Abstract

To obtain a sufficient antenna gain which the conventional vehicle window glass has not been able to obtain.SOLUTION: A vehicle window glass according to one embodiment is arranged along the lateral side 113 of a glass plate 101 in a manner that a first power supply electrode 11 is positioned upward of a first earth electrode 14. A second power supply electrode 21 and a second earth electrode 24 are arranged along the upper side or the lower side of the glass plate 101. A first earth side element 15, which is a single element extending in the horizontal direction apart from the lateral side 113 of the glass plate 101 and having one open end, is connected to the first earth electrode 14. A first power supply side element 12 includes a first power supply side element 12a, which has an open end and a part extending to the horizontal direction apart from the lateral side 113 of the glass plate 101, and is connected to the first power supply electrode 11. A first antenna 1 and a second antenna 2 are arranged so as not to be capacitively coupled.SELECTED DRAWING: Figure 1

Description

The present invention relates to a window glass for a vehicle, for example, a window glass for a vehicle provided with an antenna for receiving radio waves such as broadcast waves.

Vehicle windowpanes are equipped with various functional members such as antennas that can receive radio waves such as broadcast waves. For example, it is also known that a vehicle window glass is equipped with a so-called diversity antenna in which a plurality of antennas capable of receiving radio waves in a specific broadcast wave frequency band are arranged. As described above, the antennas (s) provided in the window glass for a vehicle have a limited space such as a narrow area for arranging them.

For example, since the rear glass is provided with a heating region such as a heating wire (defogger) in the central portion, there is a limitation that the antenna must be arranged in a limited blank region in the peripheral portion. Further, even when the antenna is arranged on the windshield, it is necessary to narrow the area where the antenna is arranged so as not to obstruct the driver's field of view. Narrowing the area where the antenna is placed is the same for the side glass (rear quarter, etc.) so as not to obstruct the view of the passenger.

As a diversity antenna for receiving radio waves of such broadcast waves, it is also known that an antenna for receiving radio waves for terrestrial digital television broadcast waves is mounted on a window glass of a vehicle. For example, Patent Document 1 discloses that an antenna conductor for receiving a radio wave for terrestrial digital television broadcasting is arranged on a rear quarter glass in a predetermined pattern, and the antenna conductor receives diversity.

Japanese Unexamined Patent Publication No. 2009-049706

However, the technique described in Patent Document 1 is equipped with an antenna having a higher gain, although a predetermined gain can be obtained in the frequency band (470 MHz to 720 MHz) assigned to the terrestrial digital television broadcast wave. There is a demand for windowpanes for vehicles.

In order to solve this problem, the present invention provides a window glass for a vehicle equipped with an antenna capable of receiving radio waves of terrestrial digital television broadcasting waves and obtaining a high antenna gain.

The vehicle window glass according to an embodiment is a vehicle window glass attached to a vehicle, comprising a glass plate and an antenna provided on the glass plate, and the antenna emits radio waves in a predetermined frequency band. It has a receivable first antenna and a second antenna, the first antenna has a first feeding conductor portion and a first ground conductor portion, and the first feeding conductor portion is a first feeding conductor portion. And a first feeding side element, the first ground conductor portion has a first ground electrode and a first ground side element, and the first feeding electrode and the first ground electrode are the first ground electrode. The feeding electrode is arranged along the side surface of the glass plate so that the feeding electrode is above the first ground electrode, and the second antenna has a second feeding conductor portion and a second ground conductor portion. The second feeding conductor portion has a second feeding electrode and a second feeding side element, and the second ground conductor portion has a second ground electrode and a second ground side element, and the second feeding electrode has a second feeding electrode. And the second ground electrode are arranged along the upper or lower side of the glass plate, and the first ground side element is connected to the first ground electrode and is horizontally separated from the side side of the glass plate. It is a single element that is stretched and has one open end, and the first feeding side element is open including a portion that is connected to the first feeding electrode and stretches in a horizontally direction away from the side side of the glass plate. It has a first element on the feeding side having an end, and the first antenna and the second antenna are arranged so as not to be capacitively coupled.

According to one embodiment, it is possible to provide a window glass for a vehicle equipped with an antenna capable of obtaining a high gain for radio waves in the frequency band of a terrestrial digital television (DTV) broadcast wave.

It is a schematic diagram of the window glass for a vehicle arranged on the left side of a vehicle among the window glass for a vehicle which concerns on embodiment. It is a schematic diagram of the window glass for a vehicle arranged on the right side of a vehicle among the window glass for a vehicle which concerns on embodiment. It is the schematic of the window glass for a vehicle explaining another form of the 1st antenna. It is the schematic of the window glass for a vehicle explaining another form of the 2nd antenna. It is a graph of the gain characteristic of the antenna formed in the window glass arranged on the left side of a vehicle. It is a graph of the gain characteristic of the antenna formed in the window glass arranged on the right side of a vehicle. It is a graph of the gain characteristic of the whole antenna formed on the window glass arranged on the left and right of a vehicle.

Configuration of Antenna for Vehicle Window Glass According to the Embodiment The vehicle window glass according to the present invention will be described. In the following description, an embodiment in a state where the window glass is attached to the body of the vehicle will be described. When the window glass is attached to the vehicle body, the opening is a portion surrounded by a frame such as a metal frame (hereinafter referred to as a body flange). The body flange is not limited to the case where the entire frame is made of metal, and resin may be contained in a part of the frame, but hereinafter, it will be described as assuming that the entire frame is made of metal (metal frame). However, the term "metal frame" as used herein includes the case where at least a part of the frame surrounding the opening is made of metal. Further, the glass plate to be the window glass includes a portion embedded in the body flange. In the following description, the window glass of the opening surrounded by the body flange is referred to as a vehicle window glass. Then, the antenna pattern of the antenna formed on the window glass for a vehicle according to the embodiment will be described. The antenna described below is a so-called bipolar type antenna in which a feeding electrode and a ground electrode are used as a pair.

Further, the drawings described below show a window glass for a vehicle in a state where a glass plate is attached to the vehicle, and the front-rear direction of the vehicle is illustrated in the drawings. The front direction of the vehicle in the drawing corresponds to the traveling direction of the vehicle. Further, the window glass for a vehicle can be applied to any of the windshield, the side glass, and the rear glass of the vehicle, but in the following description, unless otherwise specified, the side glass of the vehicle is used. Examples of the side glass of the vehicle include a rear quarter glass located on the rear side of the vehicle. The vehicle window glass according to the embodiment is particularly adopted for a non-movable fixed window glass attached to a side portion of the vehicle.

When the vehicle window glass according to the present embodiment is applied to only one of the side glasses on the left and right sides with respect to the front direction of the vehicle, only one vehicle window glass can receive radio waves in the same frequency band. , A diversity antenna having at least two channels of the first antenna and the second antenna can be configured. Further, as the vehicle window glass according to the present embodiment, the vehicle window glass having the same specifications may be applied to the two side glasses on both sides so as to be paired with each other at the positions facing each other of the vehicle. Such a vehicle can be configured with a diversity antenna of 2 channels on one side and 4 channels (or more) on both sides.

[Example of window glass for vehicles]
FIG. 1 is a schematic view of a vehicle window glass according to an embodiment. The vehicle window glass 100 shown in FIG. 1 is an example of a side glass. The vehicle window glass 100 is a side glass on the left side with respect to the front direction of the vehicle, and is an example of a fixed window in which a glass plate 101 is fitted into a substantially square opening provided in the body flange 110. The side glass on the right side with respect to the front direction may be used. Further, the vehicle window glass 100 shown in FIG. 1 may be provided with a light-shielding film (not shown) on the outer peripheral edge of the opening formed by the body flange 110. Specific examples of the light-shielding film include ceramics such as a black ceramic film. The light-shielding film is arranged so as to overlap at least a part of the first antenna and the second antenna described later, for example, at least the first feeding electrode 11, the first ground electrode 14, the second feeding electrode 21, and the second ground electrode 24. You may. As described above, the light-shielding film overlaps with at least a part of the first antenna and the second antenna, so that a part of these antennas is hard to be visually recognized and the design is improved.

The vehicle window glass 100 shown in FIG. 1 has a first antenna (for example, the left side first antenna 1) and a second antenna (for example, the left side second antenna 2). The left first antenna 1 and the left second antenna 2 are antennas capable of receiving radio waves in a predetermined frequency band (for example, the frequency band of terrestrial digital television broadcasting waves). The left first antenna 1 and the left second antenna 2 function as a two-channel diversity antenna. Hereinafter, the left first antenna 1 will be simply referred to as “first antenna 1”, and the left second antenna 2 will be simply referred to as “second antenna 2”.

The first antenna 1 is provided in the vicinity of a side extending in the vertical direction on the vehicle rear side of the vehicle window glass 100 (vehicle rear side 113 in FIG. 1). The second antenna 2 is provided in the vicinity of the side (the lower side 112 of the vehicle in FIG. 1) located below the side extending in the front-rear direction on the front side of the vehicle of the window glass 100 for the vehicle. The first antenna 1 and the second antenna 2 are formed so as to keep a certain distance from each other, and they are arranged so as not to be capacitively coupled. By arranging the first antenna 1 and the second antenna 2 in this way, interference with the other antenna can be suppressed, and the reception sensitivity of radio waves in a predetermined frequency band can be enhanced by a single antenna. The constant distance without capacitive coupling is at least 30 mm or more, preferably 50 mm or more, and more preferably 100 mm or more. In this way, even when the first antenna 1 and the second antenna 2 are arranged in the vicinity of the adjacent sides of the vehicle window glass 100, they are not capacitively coupled to each other.

In the example shown in FIG. 1, these antennas are arranged as described above, but the first antenna 1 is a side extending in the vertical direction on the vehicle front side of the vehicle window glass 100 (vehicle front side 111 in FIG. 1). It may be placed in the vicinity of. Further, the second antenna 2 may be arranged in the vicinity of the upper side (the vehicle upper side 114 in FIG. 1) of the sides extending in the front-rear direction of the vehicle window glass 100. In any case, the distance between the first antenna 1 and the second antenna 2 is arranged so as to maintain a constant distance at which they are not capacitively coupled.

The vehicle window glass 100 in FIG. 1 may be provided with another antenna ANTa in a region of the opening formed by the body flange 110 in which the first antenna 1 and the second antenna 2 are not arranged. The other antenna ANTa will be described in detail in the vehicle window glass 200 described later.

The first antenna 1 is a bipolar type and has a first feeding conductor portion 10 and a first ground conductor portion 13. The first feeding conductor portion 10 has a first feeding electrode 11 and a first feeding side element 12. The first ground conductor portion 13 has a first ground electrode 14 and a first ground side element 15. In the example shown in FIG. 1, the first feeding electrode 11 and the first ground electrode 14 are arranged so as to be arranged vertically along the rear side 113 of the vehicle so that the first feeding electrode 11 is on the upper side.

Which of the first feeding electrode 11 and the first ground electrode 14 is arranged above may be determined by the wiring of a connector provided in a circuit such as an amplifier connected to an antenna connected to each electrode. .. When the first feeding electrode 11 is arranged above the first ground electrode 14 of the vehicle window glass 100, a feeder line (not shown) is connected to the first antenna 1 via, for example, an amplifier (not shown). When connecting, the connection can be made from the lower side of the vehicle to the upper side. Therefore, when dew condensation occurs on the inside of the vehicle, water droplets can be expected to be transmitted through the feeder line to prevent intrusion into the amplifier and the first antenna 1 side. Further, the first ground electrode 14 is grounded to the body by a feeder line (not shown) or the like.

The first feeding side element 12 is connected to the first feeding electrode 11. Then, the first power feeding side element 12 extends in the horizontal direction in the direction away from the rear side 113 of the vehicle. Further, the first feeding side element 12 has a first feeding side first element 12a and a first feeding side second element 12b. The end of the first power feeding side first element 12a and the first feeding side second element 12b on the side not connected to the first feeding electrode 11 is an open end. Further, in FIG. 1, the first feeding side first element 12a and the first feeding side second element 12b are stretched in parallel. Further, although at least a part of the first power feeding side first element 12a and the first feeding side second element 12b is capacitively coupled, one element may be capacitively coupled to the other element. Further, the first power feeding side first element 12a and the first feeding side second element 12b are at the same distance, and they may be capacitively coupled.

The first ground side element 15 is connected to the first ground electrode 14. Then, the first ground side element 15 extends in the horizontal direction in a direction away from the rear side 113 of the vehicle. The end of the first ground side element 15 opposite to the first ground electrode 14 is an open end. The first ground side element 15 is provided with a length shorter than that of the first power feeding side first element 12a. The first power feeding side first element 12a, which is close to the first grounding side element 15 among the first feeding side elements 12, has at least a partial capacitive coupling with the first grounding side element 15, but the first grounding side element 15 All of may be capacitively coupled.

Here, the distance at which the elements are capacitively coupled will be described. In order for the two components to be capacitively coupled, if the distance between the two adjacent components is 30 mm or less, a capacitive coupling of a capacitance value effective for the antenna characteristics occurs. Further, the distance between two adjacent components is preferably 20 mm or less, more preferably 15 mm or less. The lower limit of the distance at which two adjacent components are capacitively coupled may be more than 0 mm, and is preferably 3 mm or more, for example.

The second antenna 2 is a bipolar type as described above, and has a second feeding conductor portion 20 and a second ground conductor portion 23. The second feeding conductor portion 20 has a second feeding electrode 21 and a second feeding side element 22. The second ground conductor portion 23 has a second ground electrode 24 and a second ground side element 25. In the example shown in FIG. 1, the second feeding electrode 21 and the second ground electrode 24 are arranged side by side along the lower side 112 of the vehicle so that the second ground electrode 24 is on the front side.

The second feeding side element 22 includes a second feeding side first element and a second feeding side second element connected to the second feeding electrode 21. In the example shown in FIG. 1, the second feeding side first element has a second feeding side first connection element 22a, a second feeding side first horizontal element 22b, and a second feeding side second horizontal element 22c. Further, the second feeding side second element has a second feeding side second connection element 22d and a second feeding side third horizontal element 22e.

The second feeding side first connection element 22a is connected to the second feeding electrode 21. The first connection element 22a on the second feeding side extends in a direction away from the close side (for example, the lower side 112 of the vehicle) of the second feeding electrode 21. For example, the second power feeding side first connection element 22a is an element extending in the vertical direction (vertical direction) of the vehicle. The second horizontal element 22b on the second feeding side and the second horizontal element 22c on the second feeding side branch off from the vicinity of the end opposite to the second feeding electrode 21 of the first connecting element 22a on the second feeding side and extend. .. That is, the second horizontal element 22b on the second feeding side and the second horizontal element 22c on the second feeding side start from the vicinity of the end opposite to the second feeding electrode 21 of the first connecting element 22a on the second feeding side. Stretch in the opposite directions toward the horizontal direction. Further, the ends of the second horizontal element 22b on the second feeding side and the second horizontal element 22c on the second feeding side that are not connected to the first connecting element 22a on the second feeding side are open ends. In addition, in this specification, the "proximity side" means the side closest to the predetermined part among the openings made by the body flange 110 (120).

The second feeding side second connection element 22d is connected to the second feeding electrode 21. The second connecting element 22d on the second feeding side extends in a direction away from the close side (lower side 112 of the vehicle) of the second feeding electrode 21. For example, the second power feeding side second connection element 22d is an element extending along the second power feeding side first connection element 22a in the vertical direction (vertical direction) of the vehicle. The third horizontal element 22e on the second feeding side is in the direction opposite to the second ground electrode 24 side from the vicinity of the end of the second connecting element 22d on the second feeding side opposite to the second feeding electrode 21 (for example,). Extend horizontally in the direction toward the rear of the vehicle). The end of the second horizontal element 22e on the second power supply side that is not connected to the second connection element 22d on the second power supply side is an open end. Further, at least a part of the second horizontal element 22e on the second feeding side is capacitively coupled to the second horizontal element 22c on the second feeding side.

In FIG. 1, the second ground side element 25 has a second ground side connection element 25a and a second ground side horizontal element 25b. The second ground side connection element 25a is connected to the second ground electrode 24 and extends in a direction away from the proximity side (vehicle lower side 112) of the second ground electrode 24. For example, the second ground side connection element 25a is an element that extends in the vertical direction (vertical direction) of the vehicle. The second ground side horizontal element 25b is in a direction opposite to the second feeding electrode 21 side (for example, a direction toward the front side of the vehicle) from the vicinity of the end portion of the second ground side connection element 25a opposite to the second ground electrode 24. ) Is stretched horizontally. The end of the second ground side horizontal element 25b on the side not connected to the second ground side connection element 25a is an open end.

Further, as shown in FIG. 1, the second feeding side first horizontal element 22b and the second feeding side second horizontal element 22c are in a direction away from the closer side (vehicle lower side 112) than the second ground side horizontal element 25b. Is placed in. Further, at least a part of the second power feeding side first horizontal element 22b is capacitively coupled to the second ground side horizontal element 25b.

[First modification of vehicle window glass]
FIG. 2 is a schematic view of a vehicle window glass according to an embodiment. The vehicle window glass 200 shown in FIG. 2 is a first modification of the side glass. The vehicle window glass 200 is an example of a fixed window having a side glass on the right side with respect to the front direction of the vehicle and a glass plate 102 fitted in a substantially square opening provided in the body flange 120. The vehicle window glass 200 shown in FIG. 2 may be applied to the side glass on the left side with respect to the front direction of the vehicle. Further, the vehicle window glass 200 shown in FIG. 2 may be provided with a light-shielding film on the outer peripheral edge of the opening formed by the body flange 120 and the glass plate 102. In the following description, the same component names are used for the vehicle window glass 100 and the vehicle window glass 200, but the vehicle window is used to distinguish between the vehicle window glass 100 and the vehicle window glass 200. Even if the glass 100 and the window glass 200 for a vehicle have the same element, different reference numerals are given.

The vehicle window glass 200 shown in FIG. 2 has a first antenna and a second antenna, similarly to the vehicle window glass 100. Hereinafter, the first antenna and the second antenna provided on the vehicle window glass 200 will be referred to as a first antenna 3 and a second antenna 4, respectively. Further, the vehicle window glass 200 may have another antenna ANTa. Like the first antenna 1 and the second antenna 2, the first antenna 3 and the second antenna 4 are antennas capable of receiving radio waves in a predetermined frequency band (for example, the frequency band of terrestrial digital television broadcasting waves). Further, the first antenna 3 and the second antenna 4 function as a two-channel diversity antenna.

Further, the first antenna 3 and the second antenna 4 in the vehicle window glass 200 can function as a 4-channel diversity antenna in cooperation with the first antenna 1 and the second antenna 2 in the vehicle window glass 100.

The first antenna 3 is provided in the vicinity of a side extending in the vertical direction on the vehicle rear side of the vehicle window glass 200 (vehicle rear side 123 in FIG. 2). The second antenna 4 is provided in the vicinity of the side (the lower side 122 of the vehicle in FIG. 2) located below the side extending in the front-rear direction on the front side of the vehicle of the window glass 200 for the vehicle. The first antenna 3 and the second antenna 4 are formed so as to keep a certain distance from each other, and they are arranged so as not to be capacitively coupled.

The vehicle window glass 200 shown in FIG. 2 may be arranged in the vicinity of the side where the first antenna 3 extends in the vertical direction on the vehicle front side of the vehicle window glass 200 (vehicle front side 121 in FIG. 2). .. Further, the second antenna 4 may be arranged in the vicinity of the side (the vehicle upper side 124 in FIG. 2) located above the side extending in the front-rear direction of the vehicle window glass 200.

The first antenna 3 is an antenna corresponding to the first antenna 1 of the vehicle window glass 100 on the vehicle window glass 200. That is, the first feeding conductor portion 30, the first feeding electrode 31, the first feeding side element 32, the first ground conductor portion 33, the first ground electrode 34, and the first ground side element 35 shown in FIG. 2 are respectively. It is a component corresponding to the first feeding conductor portion 10, the first feeding electrode 11, the first feeding side element 12, the first ground conductor portion 13, the first ground electrode 14, and the first ground side element 15. However, there is a difference in the shape of the feeding side element between the first antenna 1 and the first antenna 3. Therefore, in the following, the shape of the feeding side element different from that of the first antenna 1 in the first antenna 3 will be described.

The first feeding conductor portion 10 of the first antenna 1 in the vehicle window glass 100 has a first feeding side first element 12a and a first feeding side second element 12b. On the other hand, in the vehicle window glass 200, the feeding side element provided in the first feeding conductor portion 30 of the first antenna 3 is a so-called "single element" composed of only the first feeding side element 32. The point is different.

The first feeding side element 32 is connected to the first feeding electrode 31, extends horizontally from the first feeding electrode 31, and is a second ground conductor portion from the vicinity of the end opposite to the first feeding electrode 31. It has an L-shape with a bent portion extending to the side opposite to the 43 side. The end of the L-shape opposite to the first feeding electrode 31 is an open end. Further, in the first power feeding side element 32, at least a part of the horizontally extending portion may be capacitively coupled to the first ground side element 35, and the entire horizontally extending portion is the first ground side element. It may be capacitively coupled with 35.

Next, the second antenna 4 will be described. The second antenna 4 is an antenna corresponding to the second antenna 2 of the vehicle window glass 100 in the vehicle window glass 200. That is, the second feeding conductor portion 40, the second feeding electrode 41, the second feeding side element 42, the second ground conductor portion 43, the second ground electrode 44, and the second ground side element 45 shown in FIG. 2 are respectively. It corresponds to the second feeding conductor portion 20, the second feeding electrode 21, the second feeding side element 22, the second ground conductor portion 23, the second ground electrode 24, and the second ground side element 25. The second antenna 4 and the second antenna 2 have substantially the same shape.

Therefore, the second feeding side first connection element 42a, the second feeding side first horizontal element 42b, the second feeding side second horizontal element 42c, the second feeding side connection element 42d, the second feeding side third horizontal element 42e, The second ground side connection element 45a and the second ground side horizontal element 45b are the second power supply side first connection element 22a, the second power supply side first horizontal element 22b, the second power supply side second horizontal element 22c, and the second, respectively. 2 Corresponds to the second feeding side connection element 22d, the second feeding side third horizontal element 22e, the second ground side connecting element 25a, and the second ground side horizontal element 25b. The length of each element can be appropriately adjusted depending on the shape of the window glass, the shape of the arrangement area of other antennas, and the like.

Further, as shown in FIG. 2, in addition to the first antenna 3 and the second antenna 4, the vehicle window glass 200 receives radio waves in a frequency band different from those of the first antenna 3 and the second antenna 4. An antenna (AM / FM antenna ANTa) may be provided. The AM / FM antenna ANTa is, for example, a frequency band of AM broadcast waves (for example, 530 kHz to 1720 kHz) and a frequency band of FM broadcast waves (for example, 76 MHz to 108 MHz), which are lower frequency bands than terrestrial digital television broadcast waves. Can receive at least one or both radio waves. In FIG. 2, the area where the AM / FM antenna ANTa is arranged is shown by hatching. The AM / FM antenna ANTa is arranged in a region of the vehicle window glass 200 excluding the region provided with the right first antenna 3 and the right second antenna 4.

[Variation example of the first antenna 1]
The first antennas 1a to 1d, which are modified examples of the first antenna 1, will be described with reference to FIG. The modified example of the first antenna 1 is not limited to the first antennas 1a to 1d. In the first antenna 1a, one element of the first feeding side first element 12a and the first feeding side second element 12b is connected to a portion other than both ends of the other element, and the first antenna 1a is connected in a direction different from the horizontal direction. It has a connecting element 12c to be stretched. The connecting element 12c may be configured to be provided with a first feeding side second element 12b as an element that bends from the vicinity of one end and extends in the horizontal direction. In this case, it is preferable that the length of the element extending in the horizontal direction (second element 12b on the first feeding side) is longer than the length of the connecting element 12c because the antenna gain for horizontal polarization can be improved.

The first antenna 1b has a connection element 12d in which at least one of the first feeding side first element 12a and the first feeding side second element 12b is connected to the first feeding electrode 11 and extends in a direction different from the horizontal direction. Have. The first power feeding side second element 12b may be provided as an element that bends from the vicinity of the end portion of the connecting element 12d and extends in the horizontal direction. In this case, it is preferable that the length of the element extending in the horizontal direction (second element 12b on the first feeding side) is longer than the length of the connecting element 12d because the antenna gain for horizontal polarization can be improved.

The first antenna 1c has an extension element 12e formed by bending at least one of the first feeding side first element 12a and the first feeding side second element 12b in a direction different from the horizontal direction. The extension element has a configuration in which the tip is an open end.

The first antenna 1d shows another form of the first ground side element. The first ground side element 15a of the first antenna 1d has an extension element formed by bending in a direction different from the horizontal direction on the side opposite to the first ground electrode 14 side, and the tip thereof is an open end. Further, the first ground side element 15a has a connection element (not shown) that is connected to the first ground electrode 14 and extends in a direction different from the horizontal direction, and is bent horizontally from the vicinity of the end portion of the connection element. It may be configured to extend in the direction. In this case, it is preferable that the length of the element extending in the horizontal direction is longer than the length of the connecting element because the antenna gain for horizontal polarization can be improved.

[Modification example of the second antenna 2]
The second antennas 2a and 2b, which are modified examples of the second antenna 2, will be described with reference to FIG. In the second antennas 2a and 2b, the second feeding side element 22 does not include the second feeding side second connection element 22d. That is, in the second feeding side element 22 of the second antenna 2a, the second feeding side third horizontal element 22e is directly connected to the second feeding electrode 21. On the other hand, in the second feeding side element 22 of the second antenna 2b, the second feeding side third horizontal element 22e is connected to a portion other than both ends of the second feeding side first connecting element 22a.

Further, at least one of the second feeding side first horizontal element 22b, the second feeding side second horizontal element 22c, and the second feeding side third horizontal element 22e can be bent in a direction different from the horizontal direction (not shown). The extension element may be provided and the tip of the extension element may be an open end. The extension element (not shown) extends from the (open) end of the second feeding side first horizontal element 22b, the second feeding side second horizontal element 22c, and the second feeding side third horizontal element 22e shown in FIG. Corresponds to the element to be used.

Further, the second ground side element 25 is not limited to the example shown in FIG. For example, the second ground side element 25 may be configured not to include the second ground side connection element 25a. That is, the second ground side horizontal element 25b in the second ground side element 25 may be directly connected to the second ground electrode 24. At this time, the second ground side element 25 may include the second ground side horizontal element 25b.

Further, the second ground side horizontal element 25b may have an extension element (not shown) formed by bending in a direction different from the horizontal direction, and the tip of the extension element may be an open end. The extension element (not shown) corresponds to an element extending from the (open) end of the second ground side horizontal element 25b shown in FIG.

[Vehicle window glass element length]
The element lengths of the vehicle window glass 100 and the vehicle window glass 200 shown in FIGS. 1 and 2 will be described. The length of each element is determined based on the wavelength of the received radio wave. Therefore, in the following, a method of determining the length of each element will be described using an equation.

First, the length L _H11 of the first power feeding side first element 12a, the length L _H12 of the first feeding side second element 12b, and the length L _H3 of the first feeding side element 32 will be described. These lengths L _H11 , L _H12 and L _H3 have the relationship of the equation (1a) when the wavelength of the radio wave in the frequency band of the received signal in the air is λ and the wavelength shortening rate of the glass plate 101 is k. It is good to set the length to meet.
(1/4) × λ × k ≦ L _H11 , L _H12 , L _H3 ≦ (1/2) × λ × k ・ ・ ・ (1a)
These lengths are, for example, long enough to receive radio waves in the frequency band of terrestrial digital television broadcasting waves.

Further, when the length L _H11 of the first power feeding side first element 12a, the length L _H12 of the first feeding side second element 12b, and the length L _H3 of the first feeding side element 32 satisfy the equation (1b). It is preferable that the equation (1c) is satisfied.
(11/40) × λ × k ≦ L _H11 , L _H12 , L _H3 ≦ (19/40) × λ × k ・ ・ ・ (1b)
(12/40) × λ × k ≦ L _H11 , L _H12 , L _H3 ≦ (18/40) × λ × k ・ ・ ・ (1c)

Further, the length L _H11 of the first power feeding side first element 12a, the length L _H12 of the first feeding side second element 12b, and the length L _H3 of the first feeding side element 32 are the frequency bands of the received signal. When the wavelength of the radio wave of the center frequency in the air is λ ₀ , it is more preferable to satisfy the equation (1d), particularly preferably to satisfy the equation (1e), and most preferably to satisfy the equation (1f).
(1/4) × λ ₀ × k ≦ L _H11 , L _H12 , L _H3 ≦ (1/2) × λ ₀ × k ・ ・ ・ (1d)
(11/40) × λ ₀ × k ≦ L _H11 , L _H12 , L _H3 ≦ (19/40) × λ ₀ × k ・ ・ ・ (1e)
(12/40) × λ ₀ × k ≦ L _H11 , L _H12 , L _H3 ≦ (18/40) × λ ₀ × k ・ ・ ・ (1f)
It should be noted that the wavelength λ in the air of the radio wave in the frequency band (470 MHz to 720 MHz) of the terrestrial digital television broadcasting wave is 416 mm to 638 mm, and the wavelength shortening rate k = 0.64 of the glass plate 101 (102). The length L _H11 of the first power feeding side first element 12a, the length L _H12 of the first feeding side second element 12b, and the length L _H3 of the first feeding side element 32 are set to about 67 mm or more and about 204 mm or less. can. At this time, the length L _H11 , the length L _H12 , and the length L _H3 are, for example, about 140 mm.

Next, the lengths of the first ground side element 15 and the first ground side element 35 will be described. The length _LG1 of the first ground side element 15 and the length _LG3 of the first ground side element 35 set the wavelength of the radio wave in the air of the frequency band of the received signal to λ, and shorten the wavelength of the glass plate 101 (102). When the rate is k, it is preferable to set the length to satisfy the relationship of the equation (2a).
(1/8) × λ × k ≦ L _G1, L _G3 ≦ (1/4) × λ × k… (2a)
The lengths _{LG1 and LG3} are, for example, lengths capable of receiving radio waves in the frequency band of terrestrial digital television broadcasting waves.

Further, the length _LG1 of the first ground side element 15 and the length _LG3 of the first ground side element 35 preferably satisfy the equation (2b), and more preferably satisfy the equation (2c).
(11/80) × λ × k ≦ L _G1, L _G3 ≦ (19/80) × λ × k ・ ・ ・ (2b)
(12/80) × λ × k ≦ L _G1, L _G3 ≦ (18/80) × λ × k ・ ・ ・ (2c)

Further, when the wavelength of the radio wave of the center frequency of the frequency band of the received signal in the air is λ ₀ , the length _LG1 of the first element 15 on the first ground side and the length _LG3 of the first element 35 on the first ground side It is preferable to satisfy the equation (2d), more preferably to satisfy the equation (2e), and further preferably to satisfy the equation (2f).
(1/8) × λ ₀ × k ≦ _LG1, L _G3 ≦ (1/4) × λ ₀ × k ... (2d)
(11/80) × λ ₀ × k ≦ LG1 _, L _G3 ≦ (19/80) × λ ₀ × k ・ ・ ・ (2e)
(12/80) × λ ₀ × k ≦ LG1 _, L _G3 ≦ (18/80) × λ ₀ × k ・ ・ ・ (2f)
The wavelength λ of the radio wave in the air in the frequency band of the terrestrial digital television broadcasting wave is 416 to 638 mm, and assuming that the wavelength shortening rate k = 0.64 of the glass plate 101, the first element 15 on the first earth side The length _LG1 and the length _LG3 of the first ground side element 35 may be set to about 33 mm or more and about 102 mm or less. At this time, the lengths _{LG1 and LG3 are} , for example, about 65 mm.

Further, in the vehicle window glass 100 and the vehicle window glass 200 according to the embodiment, the gain of each antenna can be increased in a relatively simple pattern by capacitively coupling each element constituting the antenna to each other. In particular, in the first antenna 1 of the window glass 100 for a vehicle, at least a part of the first element 12a on the first feeding side is capacitively coupled to the second element 12b on the first feeding side and has a capacitance with the first ground side element 15. Good to combine. Then, in the first antenna 3 of the window glass 200 for a vehicle, at least a part of the first power feeding side element 32 may be capacitively coupled to the first ground side element 35.

Further, in the vehicle window glass 100 and the vehicle window glass 200 according to the embodiment, the two antennas provided in one window glass can be used as a two-channel diversity antenna by arranging them so as not to be capacitively coupled. Further, the vehicle window glass 100 and the vehicle window glass 200 according to the embodiment can form a 4-channel diversity antenna by using two window glasses. By using such a diversity antenna, the antenna gain can be further increased. In the examples described below, the antenna gains of the first antenna 1 and the second antenna 2 and the antenna gains of the first antenna 3 and the second antenna 4 shown in FIGS. 1 and 2 will be described in detail.

(Example 1)
[Antenna gain of window glass 100 for vehicles]
This embodiment is a specific example of the window glass 100 for a vehicle, and is designed to receive radio waves of terrestrial digital television broadcasting waves. In addition, the window glass 200 for vehicles is also designed to be able to receive radio waves in the frequency band of terrestrial digital television broadcasting waves. Here, the vehicle window glass 100 is mounted on the side glass on the left side with respect to the traveling direction of the vehicle, and the vehicle window glass 200 is mounted on the side glass on the right side with respect to the traveling direction of the vehicle.

In the vehicle window glass 100, the first antenna 1 has the following shape. Capacitive coupling was performed with the distance between the first power feeding side first element 12a and the first feeding side second element 12b being 10 mm. The length L _H11 of the first power feeding side first element 12a and the length L _H12 of the first feeding side second element 12b were set to 140 mm. The length _LG1 of the first ground side element 15 was set to 65 mm, and the distance from the first power feeding side first element 12a was set to about 21 mm for capacitive coupling.

The length L _H11 of the first power feeding side first element 12a and the length L _H12 (= 140 mm) of the first feeding side second element 12b are wavelengths λ = 416 mm in the air of radio waves in the frequency band of terrestrial digital broadcasting waves. It is ~ 638 mm, the wavelength shortening rate k of the glass plate 101 is k = 0.64, and is within the range of L _H11 , L _H12 ≈ 67 mm to 214 mm. Further, the lengths L _H11 and L _H12 had a relationship of 0.43 × λ × k.

Further, the length _LG1 (= 65 mm) of the first ground side element 15 was within the range of _LG1 ≈ 33 mm to 102 mm, and the length _LG1 had a relationship of 0.20 × λ ₀ × k. The first feeding electrode 11 and the first grounding electrode 14 had a substantially square shape of about 18 mm × about 17 mm, and the first feeding electrode 11 was arranged above the first grounding electrode 14 by about 21 mm.

Further, in the vehicle window glass 100, the second antenna 2 has the following shape. The length of the first connecting element 22a on the second feeding side was 60 mm, the length of the first horizontal element 22b on the second feeding side was 40 mm, and the length of the second horizontal element 22c on the second feeding side was 90 mm. The length of the second connecting element 22d on the second feeding side was 50 mm, and the length of the third horizontal element 22e on the second feeding side was 80 mm. The length of the second ground side connecting element 25a is 50 mm, and the length of the second ground side horizontal element 25b is 110 mm. The second feeding electrode 21 and the second ground electrode 24 have a substantially square shape of about 18 mm × about 17 mm, and the distance between the second feeding electrode 21 and the second ground electrode 24 is about 21 mm. The first antenna 1 and the second antenna 2 are arranged at a distance of 100 mm or more.

FIG. 5 is a graph of the gain characteristics of the antenna formed on the window glass arranged on the left side of the vehicle. The antenna gain shown in FIG. 5 was measured using a vehicle window glass 100 designed under the above conditions. The numerical value of the antenna gain (gain) in FIG. 5 indicates the average value of the antenna gains measured at predetermined angles in the entire circumference of the vehicle in the horizontal plane. For the vehicle window glass 200 described later, the average value of the antenna gain was measured under the same conditions.

Specifically, FIG. 5 is a graph of antenna gain measured with respect to the horizontal polarization of the antenna in the vehicle window glass 100. As shown in FIG. 5, in the vehicle window glass 100, a gain of -10 [dBd] or more was obtained over the frequency band (470 MHz to 720 MHz) of the terrestrial digital television broadcast wave. As shown in FIG. 5, a higher antenna gain was obtained for the first antenna 1 than for the second antenna 2. Further, in FIG. 5, the antenna gain of the diversity antenna using the first antenna 1 and the second antenna 2 is shown in a graph of 2ch synthesis, but the diversity antenna has a higher gain than the one-channel antenna. ..

(Example 2)
[Antenna gain of window glass 200 for vehicles]
This embodiment is a specific example of the window glass 200 for a vehicle, and is specified to receive radio waves of terrestrial digital television broadcasting waves as in the first embodiment. In the vehicle window glass 200, the horizontal length from the first feeding electrode 31 of the first feeding side element 32 to the bent portion of the element is 50 mm, and the length from the bent portion to the open end is 70 mm. That is, the length L _H3 of the first power feeding side element 32 is set to 120 mm. The length _LG3 of the first ground side element 35 was set to 50 mm, and the distance from the first feeding side element 32 was set to about 21 mm for capacitive coupling.

The length L _H3 (= 120 mm) of the first power feeding side element 32 has a wavelength λ = 416 mm to 638 mm of radio waves in the air in the frequency band of terrestrial digital broadcasting waves, and a wavelength shortening rate k = 0.64 of the glass plate 101. Yes, it was set within the range of L _H3 ≈ 67 mm to 207 mm. Further, the length L _H3 had a relationship of 0.35 × λ ₀ × k.

Further, the length _LG3 (= 50 mm) of the first ground side element 35 was within the range of _LG3 ≈ 33 mm to 102 mm, and the length _LG3 had a relationship of 0.15 × λ ₀ × k. The first feeding electrode 31 and the first ground electrode 34 had a substantially square shape of about 18 mm × about 17 mm, and the first feeding electrode 31 was arranged above the first ground electrode 34 at a distance of about 21 mm.

Further, in the vehicle window glass 200, the second antenna 4 has the following shape. The length of the first connecting element 42a on the second feeding side was 60 mm, the length of the first horizontal element 42b on the second feeding side was 60 mm, and the length of the second horizontal element 42c on the second feeding side was 60 mm. The length of the second feeding side connecting element 42d was 50 mm, and the length of the second feeding side third horizontal element 42e was 110 mm. The length of the second ground side connecting element 45a is 50 mm, and the length of the second ground side horizontal element 45b is 80 mm. The second feeding electrode 41 and the second ground electrode 44 have a substantially square shape of about 18 mm × about 17 mm, and the distance between the second feeding electrode 41 and the second ground electrode 44 is about 21 mm.

Further, in the vehicle window glass 200, the shortest distance between the second horizontal element 42b on the second feeding side and the second horizontal element 42c on the second feeding side and the AM / FM antenna ANTa is set to 20 mm.

FIG. 6 is a graph of antenna gain measured with respect to the horizontal polarization of the antenna in the vehicle window glass 200 designed under the above conditions. As shown in FIG. 6, in the vehicle window glass 200, a gain of -14 [dBd] or more was obtained over the frequency band (470 MHz to 720 MHz) of the terrestrial digital television broadcast wave. As shown in FIG. 6, a higher antenna gain was obtained for the first antenna 3 than for the second antenna 4. Further, the antenna gain of the diversity antenna using the first antenna 3 and the second antenna 4 is shown in the graph of 2ch synthesis. The diversity antenna was able to obtain a higher gain than the one-channel antenna.

(Example 3)
[Antenna gain of diversity antenna using 4 channels]
FIG. 7 measures the horizontal polarization of the entire antenna formed on the vehicle window glass 100 and the vehicle window glass 200, which are arranged on the side glasses on the left side (Example 1) and the right side (Example 2) of the vehicle, respectively. It is a graph of the antenna gain. The antenna gain shown in FIG. 7 is obtained by synthesizing the antennas used in the measurements of FIGS. 5 and 6 for 4 channels. As shown in FIG. 7, by using a 4-channel diversity antenna, an antenna gain of -1 [dBd] or more was obtained over the frequency band (470 MHz to 720 MHz) of the terrestrial digital television broadcast wave.

Although the invention made by the present inventor has been specifically described above based on the embodiments, the present invention is not limited to the embodiments already described, and various changes can be made without departing from the gist thereof. It goes without saying that it is possible.

1 1st antenna (1st antenna on the left side)
2 2nd antenna (2nd antenna on the left side)
3 1st antenna (1st antenna on the right side)
4 2nd antenna (2nd antenna on the right side)
10 1st power feeding conductor 11 1st feeding electrode 12 1st feeding side element 12a 1st feeding side 1st element 12b 1st feeding side 2nd element 13 1st ground conductor part 14 1st ground electrode 15 1st ground side element 20 2nd feeding conductor 21 2nd feeding electrode 22 2nd feeding side element 22a 2nd feeding side 1st connection element 22b 2nd feeding side 1st horizontal element 22c 2nd feeding side 2nd horizontal element 22d 2nd feeding side second 2 Connection element 22e 2nd power supply side 3rd horizontal element 23 2nd ground conductor part 24 2nd ground electrode 25 2nd ground side element 25a 2nd ground side connection element 25b 2nd ground side horizontal element 30 1st power supply conductor part 31 1st power feeding electrode 32 1st feeding side element 33 1st ground conductor part 34 1st ground electrode 35 1st ground side element 40 2nd feeding conductor part 41 2nd feeding electrode 42 2nd feeding side element 42a 2nd feeding side second 1 Connection element 42b 2nd power supply side 1st horizontal element 42c 2nd power supply side 2nd horizontal element 42d 2nd power supply side connection element 42e 2nd power supply side 3rd horizontal element 43 2nd earth conductor part 44 2nd earth electrode 45th 2 Ground side element 45a 2nd ground side connection element 45b 2nd ground side horizontal element ANTa AM / FM antenna 100, 200 Vehicle window glass 101, 102 Glass plate 110, 120 Body flange 111, 121 Vehicle front side 112, 122 Vehicle Lower side 113, 123 Vehicle rear side 114, 124 Vehicle upper side

Claims (22)

A vehicle windowpane that can be attached to a vehicle.
With a glass plate
Equipped with an antenna provided on the glass plate
The antenna has a first antenna and a second antenna capable of receiving radio waves in a predetermined frequency band.
The first antenna has a first feeding conductor portion and a first ground conductor portion.
The first feeding conductor portion has a first feeding electrode and a first feeding side element.
The first ground conductor portion has a first ground electrode and a first ground side element.
The first feeding electrode and the first grounding electrode are arranged along the side of the glass plate so that the first feeding electrode is above the first grounding electrode.
The second antenna has a second feeding conductor portion and a second ground conductor portion.
The second feeding conductor portion has a second feeding electrode and a second feeding side element.
The second ground conductor portion has a second ground electrode and a second ground side element.
The second feeding electrode and the second ground electrode are arranged along the upper side or the lower side of the glass plate.
The first ground side element is a single element that is connected to the first ground electrode and extends horizontally away from the side of the glass plate and has one open end.
The first feeding side element has a first feeding side element that is connected to the first feeding electrode and has an open end including a portion extending horizontally away from the side of the glass plate.
The first antenna and the second antenna are arranged so as not to be capacitively coupled.
Window glass for vehicles. The window glass for a vehicle according to claim 1, wherein at least a part of the first power feeding side element and the first ground side element are capacitively coupled. Claim 1 or 2 that the first element on the first feeding side extends from the vicinity of the end opposite to the first feeding electrode to the side opposite to the first ground conductor portion and becomes L-shaped. Window glass for vehicles described in. 13. The vehicle window glass according to any one of the items. The window glass for a vehicle according to claim 4, wherein at least a part of the first power feeding side first element and the first feeding side second element are capacitively coupled. When the wavelength of radio waves in the predetermined frequency band in the air is λ and the wavelength shortening rate of the glass plate is k,
The window glass for a vehicle according to claim 4 or 5, wherein the distance L _H12 of the first power feeding side second element is (1/4) × k × λ or more and (1/2) × k × λ or less. .. When the wavelength in the air of the radio wave of the center frequency of the predetermined frequency band is λ ₀ ,
The window glass for a vehicle according to claim 6, wherein the distance L _H12 is (1/4) × k × λ ₀ or more and (1/2) × k × λ ₀ or less. When the wavelength of radio waves in the predetermined frequency band in the air is λ and the wavelength shortening rate of the glass plate is k,
The method according to any one of claims 1 to 7, wherein the distance L _H11 of the first element on the first power feeding side is (1/4) × k × λ or more and (1/2) × k × λ or less. Window glass for vehicles. When the wavelength in the air of the radio wave of the center frequency of the predetermined frequency band is λ ₀ ,
The window glass for a vehicle according to claim 8, wherein the distance L _H11 is (1/4) × k × λ ₀ or more and (1/2) × k × λ ₀ or less. When the wavelength of radio waves in the predetermined frequency band in the air is λ and the wavelength shortening rate of the glass plate is k,
The vehicle according to any one of claims 1 to 9, wherein the distance _LG1 of the first ground side element is (1/8) × k × λ or more and (1/4) × k × λ or less. Window glass for. When the wavelength in the air of the radio wave of the center frequency of the predetermined frequency band is λ ₀ ,
The window glass for a vehicle according to claim 10, wherein the distance _LG1 is (1/8) × k × λ ₀ or more and (1/4) × k × λ ₀ or less. The first ground side element has a first ground side auxiliary element extending in a direction away from the first ground side element starting from a horizontal end opposite to the first ground electrode. The vehicle window glass according to any one of 1 to 11. The second power feeding side element is
A second feeding side first connection element that is connected to the second feeding electrode and extends in a direction away from the upper side close to the second feeding electrode or the proximity side corresponding to the lower side.
A second horizontal element on the second feeding side and a second horizontal element on the second feeding side, which branch and extend from the vicinity of the end of the first connecting element on the second feeding side opposite to the second feeding electrode.
It has a second feeding side third horizontal element that is electrically connected to the second feeding electrode and extends to the side opposite to the second ground electrode side.
The second ground side element has a second ground side horizontal element that is electrically connected to the second ground electrode and extends in the horizontal direction opposite to the second feed electrode side.
The vehicle window glass according to any one of claims 1 to 12. The vehicle according to claim 13, wherein the second power feeding side first horizontal element and the second feeding side second horizontal element are arranged in a direction away from the proximity side with respect to the second ground side horizontal element. Window glass. The vehicle according to claim 13 or 14, further comprising a second feeding side connecting element that is connected to the second feeding electrode and extends away from the proximity side to connect to the second feeding side third horizontal element. Window glass. 13. Window glass for vehicles. The vehicle window glass according to any one of claims 13 to 16, wherein at least a part of the second power feeding side first horizontal element and the second ground side element are capacitively coupled. The vehicle window glass according to any one of claims 1 to 17, further comprising another antenna for receiving radio waves in another frequency band lower than the predetermined frequency band. The vehicle window glass according to claim 18, wherein the other antenna receives radio waves of at least one of the frequency band of the AM broadcast wave and the frequency band of the FM broadcast wave. The vehicle window glass according to any one of claims 1 to 19, wherein the first antenna and the second antenna receive radio waves in the frequency band of terrestrial digital television broadcasting waves. The vehicle window glass according to any one of claims 1 to 20, wherein the glass plate is a fixed window glass attached to a side portion of the vehicle. Two glass plates are provided so as to be paired at opposite positions of the vehicle.
The two glass plates are each provided with two antennas capable of receiving radio waves in a predetermined frequency band, and a total of four antennas function as four-channel antennas in the vehicle according to claims 1 to 21. The vehicle window glass according to any one of the items.

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