JPH07122921A - Window glass antenna for automobile - Google Patents

Abstract

PURPOSE:To improve the attaching operation of a window glass antenna for an automobile, to save a space and to improve appearance. CONSTITUTION:The grounding pattern part of an insulated film 2 for which a radiating pattern 22 and a grounding pattern 21 are disposed is held there between a rubber insulation member 3 and a bakelite substrate 4 and the surface 2a of the radiating pattern part of the insulated film 2 and the surface 4a of the bakelite substrate are stuck to the rear window glass surface of the automobile. Since the attaching operation to the window glass can be performed while holding the relativeiy thick bakelite substrate 4 in hands, attachment can be easily performed even to the lower part of the window glass surface where inclination is sharp. Also, the space can be saved since it is constituted of a monopole antenna and the apperance can be improved since it becomes inconspicous.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a window glass antenna used in a car telephone or the like.

[0002]

2. Description of the Related Art As a window glass antenna of this type, for example, an antenna device for an automobile filed by the applicant of the present invention (actual plan 1)
No. 57807) is known. This antenna was made by adhering a film having a patterned conductor on its surface to a window glass of an automobile.

[0003]

However, since the entire antenna is formed of a film, for example, when the antenna is mounted from the inside of the vehicle to the lower part of the rear window glass surface where the inclination is steep, the hands cannot reach the back. It was difficult. or,
There was a problem in terms of appearance because it required a comparatively large space and was conspicuous. Therefore, it is an object of the present invention to provide a window glass antenna for an automobile, which has improved mounting workability, space saving, and improved appearance.

[0004]

In order to solve the above-mentioned problems, the present invention provides, in claim 1, a horizontally long grounding pattern and a vertically long radiation pattern arranged above or below this grounding pattern. It is arranged on the insulating film, a pair of feeding points are provided in the radiation pattern and the ground pattern, an insulating member such as rubber covering the ground pattern is attached to one surface of the insulating film, and the other surface of the insulating film is fixed. An automobile window glass antenna was constructed so as to adhere to the window glass surface.

In the second aspect, a plurality of insulating films are provided side by side.

[0006]

According to the first aspect of the present invention, since the insulating member having a relatively large thickness is attached to the grounding pattern portion of the insulating film, even when the antenna is attached to the inside of the window glass surface having a steep inclination, the insulating member can be manually attached. If you hold it and push it into the back of the window glass, it can be installed relatively easily. On the other hand, because it is a monopole antenna, space can be saved,
Further, since the conspicuous portion is only the radiation pattern, the appearance can be improved.

According to the second aspect, the present antenna can form a diversity antenna, for example. Therefore, it is possible to provide a diversity antenna with improved mounting workability, space saving, and improved appearance.

[0008]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is an exploded perspective view of a first embodiment of an automobile window glass antenna according to the present invention, and FIG.
It is an assembly perspective view of an Example.

The first embodiment is an embodiment of claim 1. An automotive window glass antenna 1 includes an inverted T-shaped insulating film 2 having an antenna pattern, a horizontally long rubber insulating member 3, a horizontally long bakelite substrate 4, and a power feeding coaxial cable 5 connected to the antenna pattern. And a holding metal fitting 6 for fixing the coaxial cable 5.

The insulating film 2 is a so-called FPC (Fle).
xable Printed Circuit) member,
For example, a polyimide (P
I) Formed with a film. On the surface 2a of the insulating film 2, a horizontally long grounding pattern 21 formed of a copper foil having a thickness of 35 μm, and a vertically long radiation pattern formed of a copper foil arranged above the grounding pattern 21. 22
And the grounding pattern 21 of the radiation pattern 22
A pair of feeding points 23 and 24 provided at a side end portion and one point on the grounding pattern 21 facing the end portion, and a pair of slits 2 formed at a substantially central portion of the grounding pattern 21.
5, 26 and a pair of through holes 27, 28 formed on the left and right sides of these slits 25, 26.

Although the radiation pattern 22 and the ground pattern 21 are arranged on the front surface 2a of the insulating film 2 in FIG. 1, they may be arranged on the rear surface 2b. Also, two insulating films 2 may be used and the grounding pattern 21 and the radiation pattern 22 may be sandwiched. This also applies to the second or third embodiment described later.

The rubber-based insulating member 3 is shaped like a lid and has a size enough to cover the ground pattern 21 portion. The bottom surface 3a of the insulating member 3 has a pair of protrusions 31 with concave portions. 32 is provided, and a notch 3c for passing the coaxial cable 5 is formed at the center of the wall surface portion 3b.

A pair of slits 41 and 42 are formed on the bakelite substrate 4 at the same positions as the slits 25 and 26, and a pair of protrusions 4 are formed at the same positions as the through holes 27 and 28.
3,44 are provided. Then, one protrusion 43
Penetrates the through hole 27 and fits into the recess 31a of the recessed projection 31 and the other projection 44 extends through the through hole 2
8 is fitted in the recess 32a of the projection 32 with the recess.

In the coaxial cable 5, the core wire 5a is soldered to the feeding point 23 of the radiation pattern 22, and the braided wire 5b is soldered to the feeding point 24 of the grounding pattern 21. When both patterns 21 and 22 are arranged on the surface 2a as in this embodiment, for example, both feeding points 23 and 2 are provided.
A through hole (not shown) for passing the core wire 5a and the braided wire 5b to the surface 2a side may be provided in the space 2c between the four. Next, the cable 5 is fixed to the insulating film 2 by the holding metal fitting 6. The holding metal fitting 6 is, for example, a thin metal plate formed in a U shape, and the bent portion 6a of the bent portions 6a and 6b at both ends thereof has the slits 25 and 4 respectively.
1 and the bent portion 6b has the slits 26, 42.
Plugged into. Further, the bent portions 6a and 6b are soldered to the ground pattern 21.

FIG. 2 shows the external appearance after assembly. The insulating member 3 and the bakelite substrate 4 are attached to the ground pattern 21 portion of the insulating film 2.
Then, the radiation pattern 22 on the surface 2a of the insulating film 2 and the surface 4a of the bakelite substrate 4 are adhered to the rear window glass surface of the automobile with an adhesive. still,
In this embodiment, the insulating film 2 is sandwiched between the insulating member 3 and the bakelite substrate 4. However, if the insulating member 3 is adhered to the insulating film 2 with an adhesive or the like, the bakelite substrate 4 is unnecessary. Becomes Therefore, in this case, the entire surface 2a of the insulating film 2 is attached to the window glass surface or the like.

FIG. 3 is a pattern diagram showing an example of dimensions of each part of the window glass antenna 1. The radiation pattern 22 is a strip-shaped conductor pattern having a width of about 0.3 mm and a width of about 0.3 m.
Nine pieces are arranged in parallel at m intervals, and the entire width is 5 mm and the length is 55 mm. On the other hand, the ground pattern 21 is one conductor pattern having a width of 15 mm and a length of 100 mm. Also, the width of the insulating film 2 is equal to that of the pattern 2.
It is formed to be approximately 1 mm longer in the left and right direction than the width of 1, 22.

FIG. 4 is a partially enlarged view of the radiation pattern. As shown in this figure, the radiation pattern 22 has a total of nine thin strip-shaped conductor patterns by forming eight slits in a strip-shaped copper foil. A space (copper foil surface) for providing the feeding point 23 is provided at the lower end of the radiation pattern 22.

The dimensions of this antenna are designed for the 800 MHz band (frequency band for automobile telephones). But,
Needless to say, the present invention is not limited to this 800 MHz band, and can be used in other frequency bands, such as the 1.5 GHz band. The radiation pattern 22 may be formed of a single conductor pattern,
The ground pattern 21 may be formed of a plurality of strip-shaped conductor patterns. Further, the pattern is not limited to the strip pattern, and may be a mesh pattern, for example. Further, as will be described later, since the radiation pattern 22 is attached at a position within the field of view, it is preferable to form the radiation pattern 22 with a plurality of strip-shaped patterns because it is less noticeable.

FIG. 5 is a schematic explanatory view of a window glass antenna attached to the rear window glass surface. In this example, the window glass antenna 1 is formed in an inverted T shape, and the rear window glass 6 is formed.
0 was attached to the lower horizontal side 60a and was attached to the substantially central portion of the horizontal side 60a from the inside of the vehicle. Then, ceramic print processing 61 is applied along the horizontal side 60a of the window glass 60 so that the portion of the bakelite substrate 4 is hard to see from the outside of the vehicle. On the other hand, the insulating member 3 attached to the inside of the vehicle is covered with an interior material (not shown) from the inside of the vehicle.

As described above, according to the window glass antenna 1,
When mounting the antenna below the window glass surface 60, the insulating member 3 can be held by hand and pushed into the back of the window glass surface. Even if it is difficult, the mounting work can be performed relatively easily.

Further, since it is composed of a monopole antenna, it is possible to save space.

Further, by applying the ceramic print processing 61 to the window glass surface 60, the bakelite substrate 4 is made inconspicuous, and by covering the insulating member 3 from the inside of the vehicle with an interior member or the like, the appearance can be improved. .
Further, since the insulating film 2 provided with the radiation pattern 22 is bendable, it can be attached to most vehicle types.

The antenna 1 may be attached in a T shape. In this case, the upper horizontal side 6 of the window glass 60
If the antenna 1 is attached close to 0b, and ceramic printing is performed along the upper horizontal side 60b, the same effect as when the antenna 1 is attached to the lower horizontal side 60a can be obtained.

Next, the performance of the window glass antenna 1 will be described based on actual measurement data. FIG. 6 is an average reception sensitivity data table of the window glass antenna, FIG. 7 is a directional characteristic diagram of the window glass antenna, and FIG. 8 is a standing wave ratio characteristic diagram of the window glass antenna.

The average receiving sensitivity data table of FIG. 6 is 810M.
It shows the dipole ratio average reception sensitivity (dB) in the range of Hz to 970 MHz (frequency band for car phones). From this data, it can be seen that a substantially flat reception sensitivity can be obtained within the band. The sensitivity is about -5 dB, which is almost the same level as that of a general monopole type window glass antenna.

The directional characteristic diagram of FIG. 7 is measured at 890 MHz. According to this data, the sensitivity of the vehicle in the front-rear direction (traveling direction) is about 10 dB lower than the left-right direction, but it can be said that there is no practical problem.

The standing wave ratio characteristic diagram of FIG. 8 is 770 MHz to 9
It is measured at 90 MHz. According to this data, it is about 1.5 or less over the entire frequency band (810 MHz to 970 MHz), and it can be seen that the matching of the antenna impedance in the band is practically sufficient.

As described above, it can be seen that the window glass antenna 1 according to the present invention has substantially the same electrical performance as the conventional monopole antenna.

Next, the second embodiment will be described. Figure 9
FIG. 3 is an exploded perspective view of a second embodiment of a vehicle window glass antenna according to the present invention. The second embodiment is an embodiment of claim 2. The same members as those in the first embodiment are designated by the same reference numerals and the description thereof will be omitted.

The window glass antenna 100 constitutes a diversity antenna by horizontally arranging two insulating films 2 having the antenna patterns 21 and 22 similar to those of the first embodiment, and a rubber insulating member 110. The bakelite substrate 120 has a length slightly more than twice as long as that used in the first embodiment. With these, the grounding pattern 2 of the two insulating films 2 is used.
Hold one copy.

Then, the two coaxial cables 5 are fixed to the respective insulating films 2 by the holding metal fittings 6, respectively. The bent portions 6a and 6b at both ends of the holding metal 6 are provided with the slits 25 and 26 of the grounding pattern 21 and the bakelite substrate 12, respectively.
0 slits 121 to 124 and are soldered to the respective ground patterns 21. Also, the protrusions 125 and 126 provided on both sides of the bakelite substrate 120.
Through holes 27 and 28 provided in the respective ground patterns 21
Projection 1 with a recess provided on the insulating member 110
The concave portions 111a and 112a of the grooves 11 and 112 are fitted together.

To attach the antenna 100 to a window glass, the two insulating films 2 (radiation pattern 2
An adhesive is applied to the portion (where 2 is provided) and the front side surface 120a of the bakelite substrate 120 to adhere to the window glass surface.

That is, the insulating film 2, the coaxial cable 5 and the holding metal 6 which are the same as those of the window glass antenna 1, two pieces each, the bakelite substrate 120 having the length slightly more than double and the insulating member 110 are used one piece each. As a result, a diversity antenna having substantially the same electrical performance as the window glass antenna 1 can be realized. Therefore, like the window glass antenna 1, the mounting workability is improved,
It is possible to save space and improve the appearance.

Next, a third embodiment will be described. Figure 1
FIG. 0 is an exploded perspective view of a third embodiment of an automobile window glass antenna according to the present invention. The third embodiment is a modification of the first aspect. It can also be regarded as a modification of the second embodiment. The same members as those in the first embodiment are designated by the same reference numerals and the description thereof will be omitted.

The window glass antenna 130 includes two radiation patterns 22 arranged side by side and a common grounding pattern 131 formed to have a length approximately twice that of the insulating film 13.
2 and the insulating film 132 is sandwiched between a rubber-based insulating member 133 and a Bakelite substrate 134 having a length that is approximately twice the length of the insulating film 132 to form a diversity antenna.

In the case of this antenna 130, the number of insulating films 132 is one, so that the assembling workability is improved.
Further, since the grounding pattern 131 is integrated, the length of this portion can be made shorter than that of the second embodiment. Then, it is possible to obtain substantially the same electrical performance as that of the window glass antenna 1, and to improve the mounting workability, save the space, and improve the appearance.

[0037]

According to the first aspect of the present invention, since a relatively thick insulating member is attached to the grounding pattern portion of the insulating film, this insulating member can be used even when the antenna is attached to the inside of a window glass surface having a steep slope. It can be installed relatively easily by holding it by hand and pushing it into the back of the window glass. On the other hand, since it is a monopole antenna, it is possible to save space, and since the only conspicuous part is the radiation pattern, the appearance can be improved.

In the second aspect, the present antenna can form, for example, a diversity antenna. Therefore, it is possible to provide a diversity antenna with improved mounting workability, space saving, and improved appearance.

[Brief description of drawings]

FIG. 1 is a first window glass antenna for an automobile according to the present invention.
Exploded perspective view of the embodiment

FIG. 2 is an assembled perspective view of the first embodiment.

FIG. 3 is a pattern diagram showing an example of dimensions of each part of the first embodiment.

FIG. 4 is a partially enlarged view of the radiation pattern of the first embodiment.

FIG. 5 is a schematic explanatory view when the first embodiment is attached to a window glass.

FIG. 6 is a table of average receiving sensitivity data of the first embodiment.

FIG. 7 is a directivity characteristic diagram of the first embodiment.

FIG. 8 is a standing wave ratio characteristic diagram of the first embodiment.

FIG. 9 is an exploded perspective view of the second embodiment.

FIG. 10 is an exploded perspective view of the third embodiment.

[Explanation of symbols]

 1,100,130 Automotive window glass antenna 2,132 Insulating film 3,110,133 Rubber-based insulating member 21,120,134 Grounding pattern 22 Radiating pattern 23,24 Feeding point

Claims (2)

[Claims] 1. A horizontally long grounding pattern and a vertically long radiation pattern arranged above or below the grounding pattern are arranged on an insulating film, and a pair of the radiation pattern and the grounding pattern are provided. A window glass for an automobile, characterized in that a power feeding point is provided, an insulating member such as rubber covering the ground pattern is attached to one surface of the insulating film, and the other surface of the insulating film is bonded to a window glass surface. antenna. 2. The automobile window glass antenna according to claim 1, wherein a plurality of the insulating films are provided side by side.