Vehicle antenna device

Abstract

To provide an antenna device for a vehicle which is easily manufactured and enables a wide band, and can easily adjust antenna transmission / reception characteristics.SOLUTION: An antenna device for a vehicle has a plate-like element 10, and a ground substrate 20. The plate-like element 10 has a power supply part 11 and a tip part 12, has an open part 14 that extends to the tip part 12 from the power supply part 11 with a predetermined line width so as to have a blank part 13 at the center in top view and extends from the blank part 13 between the power supply part 11 and the tip part 12, and can transmit / receive a signal of a predetermined frequency band. The ground substrate 20 has a ground part 21 that is a ground of the plate-like element 10, and a power supply point 22 to which the power supply part 11 of the plate-like element 10 is connected, and is arranged at such a position that the most of the ground part 21 do not overlap the plate-like element 10 in top view, and does not protrude from a range of the blank part 13 and the open part 14.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a vehicle antenna device, and more particularly to a vehicle antenna device that is easy to manufacture and can be made to have a wide bandwidth. [Background technology]

[0002] Recently, TEL antennas that can be mounted inside the vehicle's instrument panel have become popular as vehicle antenna devices. Such vehicle antenna devices are typically constructed by combining a metal ground plate and an antenna element, which are inserted into an insulating bracket and then installed inside the instrument panel. The size and shape of the metal ground plate are determined by the shape of the insulating bracket specified by the vehicle manufacturer.

[0003] For example, the antenna device disclosed in Patent Document 1 has a metal plate that serves as the ground cut out in part, and a resonant antenna element that resonates in a plurality of frequency bands is disposed in the cutout portion. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Re-tabled publication 2018 / 110671 Summary of the Invention [Problem to be solved by the invention]

[0005] When an antenna device for a vehicle instrument panel is assembled to an insulating bracket, the metal plate is clamped from the side and slid to insert it into the insulating bracket. However, in the case of an antenna device with a structure in which a portion of the metal plate is cut out, as disclosed in Patent Document 1, the complex shape of the metal plate can cause the metal plate to get stuck midway when sliding into the insulating bracket. Furthermore, because the metal plate has a cutout structure, the metal plate can bend when clamped from the side, which can change the antenna transmission and reception characteristics. Therefore, there has been a demand for the development of an antenna device that is easy to assemble and manufacture.

[0006] Furthermore, in recent years, there has been a demand for even wider bandwidth for TEL antennas, and it has been desirable to make the elements larger within certain limits. Furthermore, it has become necessary to adjust the antenna transmission and reception characteristics from low to high frequency bands depending on the type of vehicle in which the antenna device is installed. Therefore, there has been a demand for the development of an antenna device whose transmission and reception characteristics can be easily adjusted.

[0007] SUMMARY OF THE INVENTION In view of the above circumstances, the present invention provides a vehicle antenna device that is easy to manufacture, can be made to have a wide bandwidth, and further allows the antenna transmission and reception characteristics to be easily adjusted. [Means for solving the problem]

[0008] In order to achieve the above-mentioned object of the present invention, the vehicle antenna device of the present invention comprises a plate-shaped element having a power feed portion and a tip portion, extending with a predetermined line width from the power feed portion to the tip portion so as to leave a blank space in the center when viewed from above, and having an open portion extending from the blank space between the power feed portion and the tip portion, and capable of transmitting and receiving signals in a predetermined frequency band, and a ground substrate having a ground portion that serves as the ground of the plate-shaped element and a feed point to which the power feed portion of the plate-shaped element is connected, and being positioned in a position where the majority of the ground portion does not overlap with the plate-shaped element when viewed from above and does not extend beyond the range of the blank space and open space.

[0009] Here, the plate-like element may have any one of a C-shape, a G-shape, and a U-shape.

[0010] The ground substrate may be any substrate that extends into the open portion.

[0011] The ground plane may also extend into the blank area.

[0012] Furthermore, the insulating bracket may have a slide portion into which the plate-shaped element is inserted by sliding parallel to the plate surface of the plate-shaped element from the side opposite the open portion of the plate-shaped element, and the ground substrate may connect the open portion of the plate-shaped element so that the plate-shaped element does not bend when it is clamped from the side and inserted into the slide portion.

[0013] Furthermore, the antenna may be provided with a substrate cover that covers the ground substrate and is fixed to the plate element to connect the open portion of the plate element so that the plate element does not bend when clamped from the side.

[0014] Furthermore, the ground substrate may be provided with a connector to which a cable for transmitting and receiving signals is connected, and in order to adjust the amount of protrusion of the connector from the plate-like element, the ground substrate may be offset from the plate-like element to the side where the connector does not protrude.

[0015] The plate-like element may be any element that allows adjustment of the signal transmission / reception characteristics in a predetermined frequency band by adjusting the line width.

[0016] The ground substrate may also have fixing points to which the tips of the plate elements are fixed.

[0017] Here, the feeding portion and tip of the plate-like element are bent at right angles so as to stand upright, and the bent tips are connected to the feeding point and fixed point of the ground substrate, respectively.

[0018] The fixing point of the ground substrate to which the tip of the plate element is fixed may be electrically connected to the ground portion of the ground substrate.

[0019] Furthermore, the fixing point of the ground substrate to which the tip of the planar element is fixed may be electrically connected to the ground portion of the ground substrate via a resistor that provides a predetermined impedance value.

[0020] The ground substrate may also be configured so that the fixed point of the ground substrate to which the tip of the plate-like element is fixed can be selected to be electrically connected to the ground portion of the ground substrate, electrically connected via a resistor that provides a predetermined impedance value, or electrically open.

[0021] The plate-like element may also have a folded portion that is formed by being bent so as to stand upright and then folded back.

[0022] Here, the folded-back portion may be bent so as to stand upright, and the folded-back tip may be connected to a feeding point of the ground substrate as a feeding portion.

[0023] In addition, the plate-like element may have a folded portion that is formed by being bent so as to stand upright and then folded back, and the tip that is bent so as to stand upright and then folded back may be connected to a fixed point on the ground substrate as the tip portion.

[0024] The folded portion may overlap a part of the ground portion when viewed from above.

[0025] Furthermore, the antenna may be provided with another antenna element that is arranged in a position that does not overlap the plate-like element when viewed from above and does not extend beyond the range of the blank and open portions. [Effects of the Invention]

[0026] The vehicle antenna device of the present invention has the advantages of being easy to manufacture, being capable of widening the bandwidth, and being capable of easily adjusting the antenna transmission and reception characteristics. [Brief explanation of the drawings]

[0027] [Figure 1] FIG. 1 is a schematic top view for explaining a vehicle antenna device of the present invention. [Figure 2] FIG. 2 is a schematic top view for explaining another example of the arrangement of the ground substrate of the vehicle antenna device of the present invention. [Figure 3] FIG. 3 is a schematic top view for explaining another example of the plate-like element of the vehicle antenna device of the present invention. [Figure 4] FIG. 4 is a schematic top view for explaining another example of the arrangement of the ground substrate of the vehicle antenna device of the present invention. [Figure 5] FIG. 5 is a schematic top view for explaining another example of the shape of the plate-like element of the vehicle antenna device of the present invention. [Figure 6] FIG. 6 is a schematic top view for explaining another example of the shape of the plate-like element of the vehicle antenna device of the present invention. [Figure 7] FIG. 7 is a schematic enlarged view for explaining details of the connection portion between the plate-like element and the ground substrate of the vehicle antenna device of the present invention. [Figure 8] FIG. 8 is a schematic circuit diagram for explaining various configurations of the fixing points of the ground substrate of the vehicle antenna device of the present invention. [Figure 9] FIG. 9 is a schematic perspective view for explaining an example in which the vehicle antenna device of the present invention is applied to an insulating bracket for an instrument panel. [Figure 10] FIG. 10 is a schematic side view for explaining an example in which the vehicle antenna device of the present invention is applied to an insulating bracket for an instrument panel. [Figure 11] FIG. 11 is a schematic perspective view for explaining an example in which the plate-like element of the vehicle antenna device of the present invention is configured three-dimensionally. [Figure 12] FIG. 12 is a schematic perspective view for explaining another example in which the plate-like element of the vehicle antenna device of the present invention is configured three-dimensionally. [Figure 13] FIG. 13 is a schematic perspective view for explaining another example in which the plate-like element of the vehicle antenna device of the present invention is configured three-dimensionally. [Figure 14] FIG. 14 is a schematic diagram for explaining still another example in which the plate-like element of the vehicle antenna device of the present invention is configured three-dimensionally. DETAILED DESCRIPTION OF THE INVENTION

[0028] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings. Fig. 1 is a schematic top view illustrating a vehicle antenna device of the present invention. As shown in the drawing, the vehicle antenna device of the present invention is mainly composed of a plate-like element 10 and a ground substrate 20.

[0029] The plate-like element 10 is capable of transmitting and receiving signals in a predetermined frequency band. The plate-like element 10 is made of a conductive metal plate such as a copper plate. Here, the predetermined frequency band may be, for example, the TEL band, and more specifically, may be a wide frequency band such as 700 MHz to 960 MHz or 1710 MHz to 5000 MHz. However, the present invention is not limited to such frequency bands, and can be configured to suit a desired frequency band by adjusting various element lengths, etc.

[0030] The plate element 10 has a feed portion 11 and a tip portion 12. As shown in the figure, the plate element 10 extends with a predetermined line width from the feed portion 11 to the tip portion 12 so as to have a gap 13 in the center when viewed from above. Specifically, the plate element 10 has a C-shape. That is, the plate element 10 extends in a C-shape within a rectangular range as shown in the figure. The C-shaped plate element 10 has an opening 14 between the opposing feed portion 11 and the tip portion 12. The opening 14 extends from the gap 13 between the feed portion 11 and the tip portion 12. That is, the gap 13 and the opening 14 extend within the rectangular range to which the plate element 10 extends. Thus, in this specification, the blank portion 13 refers to the empty space near the center surrounded by the plate-like element 10, and the open portion 14 refers to the empty space sandwiched between the power supply portion 11 and the tip portion 12.

[0031] The ground substrate 20 has a ground portion 21 and a feeding point 22. The ground portion 21 serves as the ground for the planar element 10. The feeding point 22 is connected to the feeding portion 11 of the planar element 10. The ground substrate 20 may be made of a circuit board such as a glass epoxy board, but the present invention is not limited to this and can be applied to any plate-shaped object that can provide a ground portion and a feeding point.

[0032] As shown in the figure, the ground substrate 20 is arranged in a position where the ground portion 21 does not overlap the planar element 10 in a top view and does not extend beyond the gap 13 and the open portion 14. Specifically, the ground substrate 20 is arranged within the area surrounded by the C-shaped planar element 10. More specifically, in the illustrated example, the ground substrate 20 extends into the open portion 14. By being arranged in the open portion 14, the ground substrate 20 connects the open portions. In the illustrated example, an example is shown in which the ground portion 21 is arranged so as not to overlap completely with the planar element 10, but the present invention is not limited to this. The ground substrate 20 of the vehicle antenna device of the present invention is only required to be arranged so that most of the ground portion 21 does not overlap with the planar element 10, and a portion of the ground portion 21 may overlap with the planar element 10 as long as it does not affect the desired frequency band.

[0033] In the vehicle antenna device of the present invention configured as described above, the plate-like element 10 can be easily manufactured by sheet metal processing, etc. Furthermore, by arranging the plate-like element 10 so as to surround the ground substrate 20, the element length can be increased, thereby enabling a wider bandwidth.

[0034] Next, another example of the arrangement of the ground substrate of the vehicle antenna device of the present invention will be described with reference to Fig. 2. Fig. 2 is a schematic top view illustrating another example of the arrangement of the ground substrate of the vehicle antenna device of the present invention. In the figure, parts with the same reference numerals as in Fig. 1 represent the same objects. In the example shown in Fig. 1, the ground substrate 20 extends into the open portion 14 between the feed portion 11 and the tip portion 12, but in the example shown in Fig. 2, the ground substrate 20 extends into the blank portion 13. In this way, the ground portion 21 may be configured to be arranged only on the blank portion 13 side, as long as it is arranged in a position where most of the ground portion 21 does not overlap with the plate element 10 in top view and does not extend beyond the range of the blank portion 13 and the open portion 14.

[0035] Furthermore, by narrowing the width of the open portion 14 between the feed portion 11 and the tip portion 12 or by changing the line width of the plate-like element 10, it is possible to adjust the signal transmission / reception characteristics in a predetermined frequency band. FIG. 3 is a schematic top view illustrating another example of a plate-like element in a vehicle antenna device of the present invention. In the figure, parts with the same reference numerals as in FIG. 1 represent the same objects. As shown in FIG. 3, by narrowing the width of the open portion 14, it is possible to extend the element length of the plate-like element 10. This makes it possible to adjust the signal transmission / reception performance. Furthermore, the signal transmission / reception performance can also be adjusted by narrowing or widening the line width of the plate-like element 10, for example, the line width on the left and right or the line width on the top and bottom in the drawing.

[0036] Furthermore, Fig. 4 shows a schematic top view illustrating another example of the arrangement of the ground substrate of the vehicle antenna device of the present invention. In the figure, parts with the same reference numerals as in Fig. 1 represent the same objects. As shown in Fig. 4, in this example, the ground substrate 20 extends into both the blank space 13 and the open space 14. However, even in this example, the ground portion 21 is positioned so that most of it does not overlap with the plate-like element 10 when viewed from above, and does not extend beyond the range of the blank space 13 and the open space 14.

[0037] Furthermore, in the illustrated example, a patch antenna element 30, for example, is arranged as another antenna element. The patch antenna element 30 is arranged in a position that does not overlap the plate-like element 10 in top view and does not extend beyond the range of the blank space 13 and the open space 14. In this way, the other antenna element may be arranged in a position surrounded by the plate-like element 10. Note that in the illustrated example, an example is shown in which the patch antenna element 30 is arranged on the ground substrate 20, but the present invention is not limited to this. For example, the ground substrate 20 may be arranged only in the open space 14, and the patch antenna element 30 may be arranged in the blank space 13.

[0038] Next, other examples of the shape of the planar element will be described with reference to FIG. 5. FIG. 5 is a schematic top view illustrating other examples of the shape of the planar element of the vehicle antenna device of the present invention. In the figure, parts with the same reference numerals as in FIG. 1 represent the same objects. As shown in FIG. 5, in this example, the planar element 10 has a U-shape. That is, the planar element 10 extends in a U-shape within a rectangular area as shown. As shown, the planar element 10 does not extend inward on either the feeder 11 side or the tip 12 side, and the open portion 14 is not narrowed. In this example, too, a ground substrate 20 is arranged within the area surrounded by the U-shaped planar element 10.

[0039] Further, another example of the shape of the plate element will be described with reference to FIG. 6 . FIG. 6 is a schematic top view illustrating another example of the shape of the plate element of the vehicle antenna device of the present invention. In the figure, parts with the same reference numerals as in FIG. 1 represent the same objects. As shown in FIG. 6 , in this example, the plate element 10 has a G-shape. That is, the plate element 10 extends in a G-shape within a rectangular area as shown. In the C-shaped plate element 10 shown in FIG. 1 etc., the feed portion 11 and the tip portion 12 have symmetrical shapes. That is, the feed portion 11 and the tip portion 12 are configured to have approximately the same length. However, in the example shown in FIG. 6 , the feed portion 11 and the tip portion 12 have different lengths and are asymmetric. In the illustrated example, the feed portion 11 side is long and the tip portion 12 side is short. However, the present invention is not limited to this, and the feed portion 11 side may be short and the tip portion 12 side may be long. In this example, the ground substrate 20 is also arranged within the area surrounded by the G-shaped plate element 10. Specifically, the ground substrate 20 is arranged in the blank portion 13. Note that the ground substrate 20 may also be arranged on the open portion 14 side.

[0040] Next, details of the connection portion between the planar element 10 and the ground substrate 20 will be described using FIG. 7. FIG. 7 is a schematic enlarged view for explaining details of the connection portion between the planar element and the ground substrate of the vehicle antenna device of the present invention, with FIG. 7(a) being a top view and FIG. 7(b) being a side view. As shown in FIG. 7(a), in this example, the ground substrate 20 has a fixing point 23 to which the tip end 12 of the planar element 10 is fixed. As shown in the figure, the ground substrate 20 is arranged so as to partially overlap the feed portion 11 and the tip end 12. In the illustrated example, a portion of the ground portion 21 is arranged so as to overlap the planar element 10. However, most of the ground portion 21 of the ground substrate 20 is configured so as not to overlap the planar element 10. The fixing point 23 in the illustrated example is simply used to fix the ground substrate 20 to the planar element 10. That is, the ground substrate 20 is fixed between the open portion 14 by the feed point 22 and the fixing point 23. In the illustrated example, the ground substrate 20 is also provided with other fixing points 24, 25 below it to which the feeding portion 11 and the tip portion 12 are fixed. This ensures that the ground substrate 20 is securely fixed to the planar element 10.

[0041] 7(b), the feeding portion 11 and the tip portion 12 of the plate element 10 are bent at right angles so as to stand upright, and the bent tips are connected to a feeding point 22 and a fixed point 23 of the ground substrate 20, respectively. With this configuration, the plate element 10 can be easily connected to the ground substrate 20 by processing the plate element 10 into sheet metal or the like, without the need for additional wiring. Note that, although the illustrated example shows an example in which the plate element 10 and the ground substrate 20 are arranged parallel to each other, the present invention is not limited to this, and the ground substrate may, for example, be arranged at an angle.

[0042] Next, the fixed point will be described in more detail using FIG. 8. FIG. 8 is a schematic circuit diagram illustrating various configurations of the fixed point of the ground substrate of the vehicle antenna device of the present invention. In the figure, parts with the same reference numerals as in FIG. 7 represent the same components. FIG. 8(a) is a circuit diagram corresponding to FIG. 7. That is, this is an example in which the fixed point 23 of the ground substrate 20 to which the tip portion 12 of the planar element 10 is fixed is electrically open from the ground portion 21 of the ground substrate 20. However, the vehicle antenna device of the present invention is not limited to this. As shown in FIG. 8(b), the fixed point 23 may be configured to be electrically connected to the ground portion 21. That is, the tip portion 12 may be short-circuited to the ground portion 21. This changes the antenna transmission and reception characteristics. In this way, the antenna transmission and reception characteristics can be adjusted by whether or not the fixed point 23 is electrically connected to the ground portion 21. Furthermore, as shown in FIG. 8(c), the fixed point 23 may be configured to be electrically connected to the ground portion 21 via a resistor 26 that provides a predetermined impedance value. That is, the tip portion 12 may be connected to the ground portion 21 via a resistor 26. Specifically, the resistor 26 may have a resistance value of, for example, 50 Ω. The resistor 26 may also be a combination of circuit elements having multiple resistance components such as reactance and capacitance. This makes it possible to improve the antenna transmission and reception characteristics, particularly the VSWR characteristics.

[0043] Furthermore, the vehicle antenna device of the present invention may be configured so that the fixed point 23 can be selected to be electrically connected to the ground portion 21, electrically connected via a resistor 26 that provides a predetermined impedance value, or electrically open. For example, a jumper pin or the like may be used to select which connection method to use. This makes it possible to adjust the antenna transmission and reception characteristics according to the environment in which the vehicle antenna device of the present invention is used.

[0044] Next, an example in which the vehicle antenna device of the present invention is applied to an insulating bracket for an instrument panel will be described with reference to FIG. 9 . FIG. 9 is a schematic perspective view illustrating an example in which the vehicle antenna device of the present invention is applied to an insulating bracket for an instrument panel. In the figure, parts with the same reference numerals as in FIG. 1 represent the same components. As shown in the figure, an insulating bracket 40 is used in this example. The insulating bracket 40 is fixed to the vehicle's instrument panel. The insulating bracket 40 has a shape capable of accommodating a rectangular plate element 10. The insulating bracket 40 has a slide portion 41 into which the plate element 10 is inserted by sliding parallel to the plate surface of the plate element 10 from the side opposite the open portion 14 of the plate element 10. That is, the plate element 10 is clamped from the side and slid parallel to the slide portion 41 so that the plate element 10 fits into the insulating bracket 40. The vehicle antenna device of the illustrated example also has a connector 60. A cable for transmitting and receiving signals is connected to the connector 60. In the illustrated example, the connector 60 is disposed on the rear surface side of the ground substrate 20.

[0045] Here, when the plate element 10 is clamped from the side and inserted into the slide portion 41, the open portion 14 side of the plate element 10 having an open portion 14, such as a C-shape, G-shape, or U-shape, is clamped. At this time, in the vehicle antenna device of the present invention, the ground substrate 20 is configured to connect the open portions 14 of the plate element 10, so there is no risk of the plate element 10 bending. Specifically, as described with reference to FIG. 7 , the power feed portion 11 is fixed to the power feed point 22 and the tip end 12 is fixed to the fixing point 23, so that the ground substrate 20 connects the open portions 14. Therefore, when viewed as a whole, the plate element 10 has an O-shape, which is strong even when clamped from the side, and can prevent the plate element 10 from bending.

[0046] The insulating bracket 40 is not limited to one having a slide portion 41, and may of course be one having a structure in which the plate-like element 10 is pushed in from above. In this case, for example, fixing holes may be provided in the plate-like element 10 and bosses may be provided at corresponding positions on the insulating bracket 40, and after the plate-like element 10 is pushed into the insulating bracket 40 from above, the bosses that pass through the holes may be melted and fixed by ultrasonic welding or the like.

[0047] Furthermore, in the illustrated example, a board cover 50 that covers the ground substrate 20 is indicated by a dashed line. The board cover 50 is used to cover the ground substrate 20 and insulate it from the outside. In the vehicle antenna device of the present invention, the board cover 50 is configured to be fixed to the plate element 10. This makes it possible to use the board cover 50 to connect the open portion 14 of the plate element 10 so that the plate element 10 does not bend when the plate element 10 is clamped from the side. In other words, the board cover 50 is used for insulation and to prevent bending. If the ground substrate 20 were fixed only at the feed point 22 or the fixing point 23, there would be a risk of poor contact due to pressure from the side when the plate element 10 is clamped. However, by connecting the open portion 14 of the plate element 10 with the board cover 50, it is possible to further avoid the risks of bending, poor contact, etc.

[0048] As mentioned above, the signal transmission and reception performance can be adjusted by narrowing or widening the line width of the plate-like element 10, but widening the line width of the plate-like element 10 also has the effect of preventing the plate-like element 10 from bending when clamped from the side and of increasing its strength.

[0049] Here, the position of the connector when using the insulating bracket 40 will be described with reference to FIG. 10 . FIG. 10 is a schematic side view illustrating an example in which the vehicle antenna device of the present invention is applied to an insulating bracket for an instrument panel. In the figure, parts with the same reference numerals as in FIG. 9 represent the same objects. FIG. 10 shows the state after the plate element 10 has been inserted into the insulating bracket 40. As shown in the figure, the vehicle antenna device of the present invention has a connector 60. The connector 60 is connected to a cable for transmitting and receiving signals. In the illustrated example, the connector 60 is disposed on the back side of the ground substrate 20. The ground substrate 20 is disposed higher than the plate element 10 to adjust the amount of downward protrusion of the connector 60 relative to the plate element 10. In other words, the ground substrate 20 is disposed offset upward by approximately the thickness of the connector 60 so that the connector 60 does not protrude below the insulating bracket 40. Specifically, the feed portion 11 and the tip portion 12 of the plate-like element 10 are bent at right angles so as to stand upright, and the bent length is adjusted to the height of the ground substrate 20. In other words, the length at which the feed portion 11 and the tip portion 12 stand upright is adjusted to match the height of the connector 60. In the illustrated example, an example is shown in which the connector 60 is configured so as not to protrude below the plate-like element 10, but the present invention is not limited to this, and the connector may protrude below the plate-like element as appropriate depending on the shape and installation position of the insulating bracket.

[0050] When the vehicle antenna device of the present invention is applied to an insulating bracket 40, the connector 60 is disposed on the side of the opening 14, and therefore the plate element 10 is inserted into the insulating bracket 40 by sliding it parallel to the plate surface of the plate element 10 from the side opposite the opening 14 of the plate element 10. At this time, the vehicle antenna device of the present invention is easy to assemble because it is configured so that the opening 14 does not bend due to the ground substrate 20, the board cover 50, etc. Furthermore, since the shape itself is not complicated, there is little risk of it getting caught during insertion.

[0051] In the illustrated example described above, the connector 60 is disposed on the back side of the ground substrate 20, but the present invention is not limited to this. The connector may be disposed on the front side of the ground substrate as appropriate, depending on the shape and installation position of the insulating bracket. That is, the ground substrate may be offset from the plate element on the side where the connector does not protrude, in order to adjust the amount of protrusion of the connector from the plate element.

[0052] Next, another example of the plate element 10 will be described with reference to FIG. 11 . In the illustrated example described above, the plate element 10 is basically planar and is bent at a right angle so that only the feed portion 11 and the tip portion 12 are erected, as shown in FIG. 10 . However, the present invention is not limited to this, and a portion of the plate element may be configured three-dimensionally, as shown in FIG. 11 . FIG. 11 is a schematic perspective view for explaining an example of a three-dimensionally configured plate element of a vehicle antenna device of the present invention. In the figure, parts with the same reference numerals as in FIG. 1 represent the same objects. As shown in the figure, in this example, the plate element 10 has a folded portion 15 formed by being bent so as to erect and then folded back. More specifically, the folded portion 15 is bent so as to erect, and the tip folded back is connected to the feed point 22 of the ground substrate 20 as the feed portion 11. In other words, the folded portion 15 is provided three-dimensionally on the side of the feed portion 11. By providing such a folded portion 15, it is possible to further adjust the antenna transmission and reception characteristics. More specifically, it is possible to improve the gain in the horizontal direction by using the folded portion 15. In the illustrated example, the tip portion 12 is connected to the fixed point 23 of the ground substrate 20, but it may not have a fixed point as shown in FIG.

[0053] Here, in the example of Fig. 11, the folded portion 15 is shown folded upward and then folded back, but the erection direction is not limited to the illustrated example. Fig. 12 is a schematic perspective view for explaining another example in which the plate element of the vehicle antenna device of the present invention is configured three-dimensionally. In the figure, parts with the same reference numerals as in Fig. 11 represent the same objects. As shown, the folded portion 15 of the plate element 10 may be folded downward so as to erect, and the folded tip may be connected to the feed point 22 of the ground substrate 20 as the feed portion 11. In other words, the folded portion 15 may be provided three-dimensionally by being folded downward so as to erect, and then folded back.

[0054] Furthermore, in the illustrated example, the power supply unit 11 side is configured three-dimensionally by the folded portion 15, but the present invention is not limited to this. FIG. 13 is a schematic perspective view for explaining another example of a three-dimensionally configured plate element of a vehicle antenna device of the present invention. In the figure, parts with the same reference numerals as in FIG. 11 represent the same objects. As shown, the folded portion 15 of the plate element 10 is folded upright, and the folded tip is connected to the fixed point 23 of the ground substrate 20 as the tip portion 12. In other words, the folded portion 15 is three-dimensionally provided on the tip portion 12 side. By providing such a folded portion 15, it is possible to further adjust the antenna transmission and reception characteristics in the same way. Note that in the illustrated example, the folded portion 15 is three-dimensionally provided by being folded downward to be configured upright and then folded back, but the present invention is not limited to this. It may also be folded upright and then folded back, as in the example of FIG. 11. In other words, the erection direction is not particularly limited.

[0055] Furthermore, the folded-back portion 15 is not limited to being provided on the power supply portion 11 side or the tip portion 12 side as in the illustrated example above. It may be disposed at any position on the plate-like element 10 as long as it has the folded-back portion 15 formed by folding the plate-like element 10 upright and then folding it back.

[0056] Further, another example of the folded portion 15 will be described using FIG. 14 . FIG. 14 is a schematic diagram for explaining yet another example of a three-dimensionally configured plate-like element of the vehicle antenna device of the present invention, where FIG. 14(a) is a schematic top view and FIG. 14(b) is a schematic perspective view. In the figure, parts with the same reference numerals as in FIG. 11 represent the same objects. As shown in the figure, the plate-like element 10 is folded upright and then folded back, and the folded portion 15 is configured to overlap with a portion of the ground portion 21 in a top view. In this way, by configuring the three-dimensionally configured folded portion 15 to overlap with a portion of the ground portion 21, it is possible to further adjust the antenna transmission / reception characteristics. More specifically, the folded portion 15 overlapping with a portion of the ground portion 21 allows fine adjustment of the directivity. In other words, the directivity can be adjusted by adjusting the degree of overlap between the folded portion 15 and the ground portion 21.

[0057] In this way, the vehicle antenna device of the present invention can more flexibly adjust the antenna transmission and reception characteristics by changing the line width and shape of the plate-like element 10, as well as the three-dimensional shape and the degree of overlap with the ground portion 21.

[0058] In the example shown in Fig. 14, the folded portion 15 is configured to be folded back after being bent diagonally. However, the present invention is not limited to this, and the folded portion 15 may be configured to be folded back after being bent at a right angle, as shown in Fig. 11, etc. Conversely, although the folded portion 15 shown in Fig. 11, etc. is also configured to be folded back after being bent at a right angle, the present invention is not limited to this, and the folded portion 15 may be configured to be folded back after being bent diagonally, as shown in Fig. 14.

[0059] The vehicle antenna device of the present invention is not limited to the above-described illustrated example, and it goes without saying that various modifications can be made without departing from the scope of the present invention. [Explanation of symbols]

[0060] 10 Plate-shaped element 11 Power supply unit 12 Tip 13 Blank area 14 Open area 15 Folded section 20 Ground substrate 21 Grounds 22 Power supply point 23,24,25 Fixed point 26 Resistance 30 patch antenna elements 40 Insulation bracket 41 Slide section 50 Circuit board cover 60 Connectors

Claims

1. An antenna device for a vehicle, the antenna device for a vehicle comprising: a plate-like element having a power feed portion and a tip portion, extending with a predetermined line width from the power feed portion to the tip portion so as to have a blank portion in the center when viewed from above, and having an open portion extending from the blank portion between the power feed portion and the tip portion, and capable of transmitting and receiving signals in a predetermined frequency band; a ground substrate having a ground portion that serves as the ground for the plate-like element and a feeding point to which the feeding portion of the plate-like element is connected, the ground portion being disposed in a position where most of the ground portion does not overlap with the plate-like element in a top view and does not extend beyond the range of the blank portion and the open portion; A vehicle antenna device comprising:

2. 2. The vehicle antenna device according to claim 1, wherein the plate-like element has one of a C-shape, a G-shape, and a U-shape.

3. 2. The vehicle antenna device according to claim 1, wherein the ground substrate extends into the open portion.

4. 2. The vehicle antenna device according to claim 1, wherein the ground substrate extends into the blank portion.

5. 5. The vehicle antenna device according to claim 1, further comprising an insulating bracket having a slide portion into which the plate-like element is inserted by sliding it parallel to the plate surface of the plate-like element from the side opposite to the open portion of the plate-like element, the ground substrate connects the open portions of the plate elements so that the plate elements do not bend when the plate elements are held from the sides and inserted into the slide portions; 1. A vehicle antenna device comprising:

6. 6. A vehicle antenna device as described in claim 5, further comprising a substrate cover that covers the ground substrate and is fixed to the plate-like element to connect the open portion of the plate-like element so that the plate-like element does not bend when the plate-like element is clamped from the side.

7. 5. The vehicle antenna device according to claim 1, further comprising a connector disposed on the ground substrate and connected to a cable for transmitting and receiving signals, In order to adjust the amount of protrusion of the connector from the plate-like element, the ground substrate is offset from the plate-like element to a side where the connector does not protrude.

1. A vehicle antenna device comprising:

8. 5. The vehicle antenna device according to claim 1, wherein the signal transmission / reception characteristics of the plate-like element in a predetermined frequency band can be adjusted by changing the line width of the plate-like element.

9. 2. The vehicle antenna device according to claim 1, wherein the ground substrate has a fixing point to which a tip end of the plate-like element is fixed.

10. 10. The vehicle antenna device according to claim 9, wherein the feeding portion and the tip end of the plate-like element are bent at a right angle so as to stand upright, and the bent tips are connected to the feeding point and the fixed point of the ground substrate, respectively.

11. 11. The vehicle antenna device according to claim 9, wherein a fixing point of the ground substrate to which the tip of the plate-like element is fixed is electrically connected to a ground portion of the ground substrate.

12. 11. The vehicle antenna device according to claim 9, wherein the fixing point of the ground substrate to which the tip of the plate-like element is fixed is electrically connected to the ground portion of the ground substrate via a resistor that provides a predetermined impedance value.

13. 11. The vehicle antenna device according to claim 9 or claim 10, wherein the ground substrate is configured so that a fixing point of the ground substrate to which the tip of the plate-like element is fixed can be selected to be electrically connected to the ground portion of the ground substrate, electrically connected via a resistor that provides a predetermined impedance value, or electrically open.

14. 2. The vehicle antenna device according to claim 1, wherein the plate-like element has a folded portion that is folded upright and then folded back.

15. 15. The vehicle antenna device according to claim 14, wherein the folded portion is bent so as to stand upright, and the folded tip is connected to a feeding point of a ground substrate as a feeding portion.

16. 10. The vehicle antenna device according to claim 9, wherein the plate-like element has a folded portion formed by being bent so as to stand upright and then folded back, and the tip of the plate-like element that is bent so as to stand upright and then folded back is connected to a fixed point of the ground substrate as the tip portion.

17. 17. The vehicle antenna device according to claim 14, wherein the folded portion overlaps a part of the ground portion in a top view.

18. 5. A vehicle antenna device as claimed in any one of claims 1 to 4, further comprising another antenna element arranged in a position that does not overlap the plate-shaped element when viewed from above and does not extend beyond the range of the blank portion and the open portion.

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