JPH10303625A - Glass antenna for vehicles - Google Patents

Abstract

(57) [Summary] [PROBLEMS] Even when an antenna conductor is provided on a window glass plate having a small area, sensitivity can be improved without obstructing the field of view. A semi-loop-shaped antenna element is provided so as to surround antenna elements e1 to e6 at one ends of antenna elements e1 to e6. It consists of an antenna conductor 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a glass antenna suitable for AM broadcast, FM broadcast, television VHF band, television VHF band, and particularly suitable for a rear side window glass plate of an automobile.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 3, a window glass antenna provided with receiving antenna patterns A1 to A37, an auxiliary pattern C, and an auxiliary pattern connection CA connected to a window glass plate 29 of an automobile by an end connection pattern B. Has been reported (registered utility model No. 2517718). FIG.
In the above, D is a feeding point.

[0003]

In this conventional example, the sensitivity of AM broadcasting and FM broadcasting is relatively good, but the number of receiving antenna patterns is large (37 in the same embodiment), and the rear side window glass of the automobile is used. When it is provided on a window glass plate having a relatively small area, such as a plate, it is necessary to reduce the interval between the receiving antenna patterns, and there is a drawback that the field of view is obstructed.

Furthermore, when the antenna is provided on a window glass plate having a relatively small area, such as a rear side window glass plate of an automobile, if the number of receiving antenna patterns is not sufficiently provided due to area restrictions, the AM broadcast is particularly required. There is a drawback that the sensitivity is not sufficient, and there has been a problem that broadcasting cannot be satisfactorily received in an area where radio waves are weak. There is also a need to be able to simultaneously receive high-frequency waves such as FM broadcast waves that are higher than AM broadcasts.

Therefore, development of a glass antenna which can be provided in a small space, does not obstruct the visual field as much as possible, and has sufficient sensitivity has been desired.

[0006]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and has a first antenna conductor, a second antenna conductor, and a third antenna conductor provided on a window glass plate of a vehicle.
, A first feeding point and a second feeding point. The first antenna conductor is provided with a plurality of antenna elements substantially in parallel, and a plurality of antenna elements is provided at one end of each of the plurality of antenna elements. The second antenna conductor is extended from the first feeding point, and comprises a semi-loop antenna conductor provided so as to surround the periphery of the first antenna conductor. A glass antenna for vehicles, wherein at least one of the antenna elements is electrically connected to the glass antenna.

Further, the present invention is provided so as to extend from the second feeding point and surround the periphery of the second antenna conductor.
The glass antenna for a vehicle described above, wherein the third antenna conductor having a semi-loop shape is provided on a window glass plate of the vehicle.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the drawings. FIG. 1 is a basic structural view of a glass antenna for a vehicle according to the present invention.

In FIG. 1, 1 is a rear side window glass plate of an automobile, 2 is a second antenna conductor, 3 is a third antenna conductor, 4 is a first feed point, 5 is a second feed point, 9 (Outside of the dotted line) is a concealing layer made of ceramic or the like formed on the rear side window glass plate 1, e1 is the first antenna element, e2 is the second antenna element, e3 is the third antenna element, e4 Denotes a fourth antenna element, e5 denotes a fifth antenna element, and e6 denotes a sixth antenna element.

The antenna elements e1 to e6 mainly function as antennas for receiving medium waves such as AM broadcast waves. The distance between the antenna elements e1 to e6 is preferably 20 to 50 mm from the viewpoint of securing the visual field and improving the sensitivity. A more preferred range is 32 to 45 mm. The number of antenna elements e1 to e6 is not particularly limited.

The second antenna conductor 2 mainly functions as an antenna for receiving high-frequency waves such as FM broadcast waves. To improve the sensitivity of the medium wave, the second antenna conductor 2 needs to be electrically connected to the antenna elements e1 to e6. In FIG. 1, the sixth antenna element e6 is the second antenna conductor 2
By connecting to the second antenna conductor 2, the second antenna conductor 2 and the antenna elements e1 to e6 are connected. The second antenna conductor 2 and the antenna elements e1 to e6 may not be directly connected to each other, but may be close to each other within 10 mm and capacitively coupled to be electrically connected. However, the direct connection has better sensitivity of the medium wave by 1 dB or more than the capacitive coupling.

When presuming reception of AM broadcast and FM broadcast, the antenna elements e1 to e6 and the second antenna conductor 2
Is the length from the first feed point 4 to the tip of each of the antenna elements e1 to 6 via the second antenna conductor 2 (conductor length not including the first feed point 4) is FM. when the wavelength at the center frequency of the broadcast band was λ _M, (λ _M /
4) The range of × K to 2λ _M × K is desirable. K is the shortening rate of the glass antenna, which is usually 0.64. If it is within this range, the number d
The sensitivity of the BFM broadcast band is improved.

The third antenna conductor 3 is provided as necessary, and mainly functions as an antenna for receiving, for example, a television VHF band or a UHF band having a higher frequency than the FM broadcast wave.

FIG. 2 is a configuration diagram of an application example of the vehicle glass antenna of FIG. In FIG. 2, reference numeral 21 denotes an inner antenna conductor, 22 denotes an outer antenna conductor, 31 denotes a folded portion of the third antenna conductor 3, and 32 denotes an auxiliary antenna conductor of the third antenna conductor 3.

The inner antenna conductor 21 and the outer antenna conductor 22 are provided as necessary, and both preferably function as antennas for receiving high-frequency waves such as FM broadcast waves, so that the sensitivity is improved. Outer antenna conductor 2
2 is preferably provided in a direction opposite to the second antenna conductor 2 in the case of receiving a high frequency such as an FM broadcast wave because it is close to non-directional.

When one of the inner antenna conductor 21 and the outer antenna conductor 22 is provided, the sensitivity in the high frequency band such as the FM broadcast wave band is improved by 1 dB or more as compared with the case where no one is provided. More preferably, both the inner antenna conductor 21 and the outer antenna conductor 22 are provided.

The folded portion 31 of the third antenna conductor 3 is provided as needed to adjust the length of the third antenna conductor 3. The auxiliary antenna conductor 32 is provided as needed in order to mainly contribute to improvement in sensitivity of, for example, a television UHF band having a higher frequency than the FM broadcast wave.

In the present invention, so-called diversity reception may be performed, in which the stronger of the received signals at the first feeding point 4 and the second feeding point 5 is selected by the selection circuit and sent to the receiver.

[0019]

EXAMPLE A glass antenna for a vehicle as shown in FIG. 2 was manufactured as an example. The side window glass plate 1 was the one on the left side of the vehicle, and the same one as shown in FIG.
The size of the side window glass plate 1 is approximately 450 mm in the vertical direction, approximately 800 mm in the horizontal direction, and the length around the opening of the vehicle body is 2500 m.
m.

The length and interval of each antenna conductor are as follows. Length of inner antenna conductor 21 (first feed point 4
Length of the half-loop part excluding the vertical part extended from)
= About 930 mm, the length of the second antenna conductor 2 (length of the half loop excluding the vertical portion extended from the first feeding point 4) = about 1275 mm, and the length of the outer antenna conductor 22 (first length) Length of the half loop excluding the vertical portion extended from the feed point 4) = about 1425 mm, and the length of the third antenna conductor 3 (the folded portion excluding the vertical portion extended from the second feed point 5) Length of half loop except 31) = about 1
530 mm.

The length of the first antenna element e1 (the length of the intersection between the first antenna element e1 and the second antenna element e2 and the tip of the first antenna element e1) = about 360 mm,
The length of the second antenna element e2 = about 350 mm, the length of the third antenna element e3 = about 350 mm, the length of the fourth antenna element e4 = about 350 mm, and the length of the fifth antenna element e5 = about 350 mm, the length of the sixth antenna element e6 (the sixth antenna element e6 and the fifth antenna element e6)
5) and the length of the tip of the sixth antenna element e6) =
About 410mm.

The length of the folded portion 31 (excluding the vertical portion) = about 100 mm, the length of the auxiliary antenna conductor 32 (excluding the vertical portion near the second feed point 5) = about 180 mm, the first antenna element e1 The distance between the second antenna element e2 and the second antenna element e2 = about 30 mm, the distance between the second antenna element e2 and the third antenna element e3 = about 27.5 mm, the third antenna element e3 and the fourth antenna element e4 Interval = about 32.5m
m, the fourth antenna element e4 and the fifth antenna element e5
Between the fifth antenna element e5 and the sixth antenna element e5.
= 32.5 mm, the distance between the first antenna element e1 and the inner antenna conductor 21 = about 10 mm, and the distance between the sixth antenna element e6 and the inner antenna conductor 21 = about 15 mm.

The distance between the second antenna conductor 2 and the inner antenna conductor 21 = about 17 mm, the distance between the second antenna conductor 2 and the outer antenna conductor 22 = about 17 mm, the outer antenna conductor 22 and the third antenna conductor 3 Approximately 17m
m, the distance between the folded portion 31 and the third antenna conductor 3 = about 1
0 mm, auxiliary antenna conductor 32 and third antenna conductor 3
= Approximately 5 mm.

The average sensitivity in the AM broadcasting band of the embodiment is
It was about 3 dB lower than the 880 mm pole antenna. Table 1 shows the sensitivity in the FM broadcast band of the embodiment. Tables 2 and 3 show the sensitivities of the embodiment in the television broadcasting band. Table 1,
The unit of sensitivity in Tables 2 and 3 is dB μV.

[0025]

[Table 1]

[0026]

[Table 2]

[0027]

[Table 3]

[0028]

According to the present invention, even when the antenna conductor is provided on a window glass plate having a relatively small area, the sensitivity of the medium wave such as an AM broadcast wave is good and the field of view can be improved without reducing the interval between the antenna patterns. Less disturbing. In addition, high-frequency reception such as FM broadcast waves higher than AM broadcasts can be simultaneously received with high sensitivity.

[Brief description of the drawings]

FIG. 1 is a basic configuration diagram of a glass antenna for a vehicle according to the present invention.

FIG. 2 is a configuration diagram of an application example of the vehicle glass antenna of FIG. 1;

FIG. 3 is a configuration diagram of a conventional example.

[Description of Signs] 1: Rear window glass plate of automobile 2: Second antenna conductor 3: Third antenna conductor 4: First feeding point 5: Second feeding point 9: Concealment layer e1: First E2: second antenna element e3: third antenna element e4: fourth antenna element e5: fifth antenna element e6: sixth antenna element

Claims (2)

[Claims] A first antenna conductor, a second antenna conductor, and a third antenna conductor provided on a window glass plate of a vehicle;
The first antenna conductor includes a first feeding point and a second feeding point, and the first antenna conductor is provided by providing a plurality of antenna elements substantially in parallel, and connecting the plurality of antenna elements at one end side of each of the plurality of antenna elements. And the second antenna conductor is extended from the first feeding point,
A second antenna conductor and at least one of a plurality of antenna elements are electrically connected to each other. antenna. 2. A semi-looped third loop extending from the second feeding point and provided to surround the periphery of the second antenna conductor.
The vehicle glass antenna according to claim 1, wherein the antenna conductor is provided on a window glass plate of the vehicle.