JPH11191713A - Glass antenna device for automobile - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable the reception of plural broadcasting bands through one antenna by providing a first filter between a first feeding point and a first tuner for passing a first frequency and attenuating a second frequency and/or a second filter between a second feeding point and a second tuner for attenuating the first frequency and passing the second frequency. SOLUTION: On a rear window pane 1 of an automobile, an antenna conductor 6 is provided while having a first feeding point 4a for receiving the first reception frequency and a second feeding point 4b for receiving the second reception frequency. Between the first feeding point 4a and the first tuner, a second filter circuit 17 is connected, and a first filter circuit 7 has a function for passing a received signal in the first reception frequency band and attenuating or cutting a received signal in the second reception frequency band. The second filter circuit 17 has a function for passing the received signal in the second reception frequency band and attenuating or cutting the received signal in the first reception frequency band.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a long wave broadcasting band (LW).
Band), medium wave broadcasting band (MW band) (530-1605 kHz)
z), short wave broadcast band (SW band) (2.3-26.1 MH)
z), radio FM broadcasting band (76-90 MHz (Japan)), radio FM broadcasting band (88-108 MHz (US)), television VHF band (90-108 MHz, 170
~ 222MHz) and TV UHF band (470 ~ 770)
The present invention relates to a glass antenna device for automobiles suitable for receiving signals such as MHz.

[0002]

2. Description of the Related Art In a conventional automotive glass antenna device for MW band reception, an antenna conductor 6 having a first feed point 4a and a defogger are provided on a rear window glass plate 1 of an automobile. 4a was sent to a tuner (not shown) (FIG. 4).

However, since the margin above the defogger of the rear window glass plate 1 is narrow, even if an attempt is made to receive a broadcast band other than the MW band, a second antenna conductor different from the antenna conductor 6 is provided. There was no space problem. Even in the case of a small windowpane such as a side windowpane other than the rear windowpane 1, there is a problem that there is no space similarly to the rear windowpane 1. Furthermore, even if the second antenna conductor is provided on the rear window glass plate 1, there is also a demand that the first antenna conductor have a function of receiving a plurality of types of broadcast bands in order to diversify the receivable broadcast bands. there were. Also,
When a plurality of feeding points are provided on the antenna conductor 6, there is a problem that the sensitivity in the MW band and the sensitivity in a broadcasting band other than the MW band deteriorate.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide a glass antenna device for an automobile which overcomes the above-mentioned disadvantages of the prior art.

[0005]

SUMMARY OF THE INVENTION The present invention provides a first power supply point for receiving a first reception frequency band and a second power supply point for receiving a second reception frequency band higher than the first reception frequency band. An antenna conductor having two feeding points is provided on a window glass plate of a vehicle, and the antenna conductor receives a first reception frequency band and a second reception frequency band, and receives a reception signal at the first feeding point. To the first tuner and the reception signal at the second feeding point to the second tuner, wherein one or both of the following (A) and (B) are connected Provided is an automotive glass antenna device having a structure. (A) a first filter circuit between a first feeding point and a first tuner for passing a reception signal in a first reception frequency band and attenuating or blocking a reception signal in a second reception frequency band; Connected connection structure. (B) a second filter circuit is provided between the second feeding point and the second tuner, for passing the reception signal in the second reception frequency band and attenuating or blocking the reception signal in the first reception frequency band; Connected connection structure.

When the antenna conductor is a first antenna conductor, a second antenna conductor having a third feeding point is provided on the window glass plate separately from the first antenna conductor.
The second antenna conductor is for receiving the first reception frequency band,
The above-mentioned glass antenna device for an automobile, which is used for receiving the reception frequency band of the first embodiment or for receiving the third reception frequency band higher than the first reception frequency band, and adopts any one of the following connection structures. .

When the antenna conductor is a first antenna conductor, a second antenna conductor having a third feeding point is provided on the window glass plate separately from the first antenna conductor.
The second antenna conductor is for receiving the first reception frequency band,
The above-mentioned glass for automobiles, which is used for receiving the reception frequency band described above or for receiving the third reception frequency band higher than the first reception frequency band, and has the following connection structure (C) or (D): An antenna device is provided. (C) A connection structure in which the third feeding point and the output of the first filter circuit are connected. (D) A connection structure in which the third feeding point and the output of the second filter circuit are connected.

The windowpane is a rear windowpane, and an electrically heated defogger having a heater wire and a bus bar for supplying power to the heater wire is provided on the rear windowpane.
A choke coil is connected between a bus bar and a DC power supply for a defogger, and the above-mentioned glass antenna device for a vehicle is provided, wherein the antenna conductor and the defogger are capacitively coupled.

[0009]

FIG. 1 is a structural view of a typical example of a glass antenna device for a vehicle according to the present invention. In FIG. 1, 1
Is the rear window glass plate of the automobile, 2 is the heater wire, 4a is the first
Power supply point, 4b is a second power supply point, 5a and 5b are bus bars,
6 is an antenna conductor, 7 is a first filter circuit, 7a is a coil, 8 is a reactance circuit, 9 is a choke coil, 1
0 is a DC power supply, 11 is a capacitor, 12a and 12b are high-frequency choke coils, 17 is a second filter circuit, 17
a is a capacitor, 20 is an arrow indicating the first tuner side,
21 indicates an arrow pointing to the second tuner side, 25a indicates a first coaxial cable, and 25b indicates a second coaxial cable. In the following description, unless otherwise specified, the unit of dimension is mm, the unit of sensitivity is dB, and the direction refers to the direction on the drawing.

In the glass antenna device for an automobile shown in FIG.
An antenna conductor 6 having a first feed point 4a for receiving a first reception frequency band and a second feed point 4b for receiving a second reception frequency band is provided on a window glass plate 1 of an automobile,
The antenna conductor 6 receives a first reception frequency band and a second reception frequency band higher than the first reception frequency band.

A first filter circuit 7 is connected between the first feeding point 4a and the first tuner.
The second filter circuit 17 is connected between the feeding point 4b of the second and the second tuner. The first filter circuit 7 has a function of passing a reception signal of the first reception frequency band and attenuating or blocking a reception signal of the second reception frequency band. The second filter circuit 17 has a function of passing a reception signal of the second reception frequency band and attenuating or blocking a reception signal of the first reception frequency band. As a result, mutual influence between the first tuner and the second tuner is eliminated as much as possible,
It is possible to prevent the sensitivity between the first reception frequency band and the second reception frequency band from deteriorating.

The first filter circuit 7 preferably has a function of attenuating a received signal in the second receiving frequency band by 5 dB or more, and when the signal is attenuated by 5 dB or more, the function is 5 dB.
As compared with the case where no attenuation is applied, the sensitivity of the first reception frequency band can be normally prevented from deteriorating by 2 dB or more.

The second filter circuit 17 preferably has a function of attenuating the received signal in the first receiving frequency band by 5 dB or more, and if the signal can be attenuated by 5 dB or more, the function is reduced by 5 dB.
Compared to the case where the attenuation is not more than B, the sensitivity of the second reception frequency band can be normally prevented from deteriorating by 2 dB or more.

As the first filter circuit 7, a low-pass filter circuit, a band-pass filter circuit, and a band elimination filter circuit can be used. However, the present invention is not limited to these, and other types of filter circuits may be used as long as they perform necessary functions.

As the second filter circuit 17, a high-pass filter circuit, a band-pass filter circuit, and a band elimination filter circuit can be used. However, the present invention is not limited to these, and other types of filter circuits may be used as long as they perform necessary functions.

In order to prevent the sensitivity from deteriorating in the first reception frequency band and the second reception frequency band in a well-balanced manner,
It is preferable to include both the first filter circuit 7 and the second filter circuit 17 as shown in FIG. However, the present invention is not limited to this, and even if only one of the first filter circuit 7 and the second filter circuit 17 is used, the sensitivity of the first reception frequency band or the second reception frequency band is deteriorated. Can be prevented.

In FIG. 1, the first filter circuit 7 comprises a coil 7a, and the second filter circuit 17 comprises a capacitor 17a. However, the first filter circuit, the second
The filter circuit 17 is not limited to the example shown in FIG. 1 and may have another circuit configuration.

If the first reception frequency band is the MW band and the second reception frequency band is the FM broadcast band or the television VHF band, the value of the coil 7a in FIG.
The range of 500 μH is usually adopted, and the range of 1.0 to 500 pF is usually adopted as the value of the capacitor 17a in FIG.

It is preferable to capacitively couple the antenna conductor 6 and the defogger from the viewpoint of improving the sensitivity. When the antenna conductor 6 and the defogger are capacitively coupled, the bus bar 5b
And the anode of the DC power supply 10 for the defogger,
At least one of the choke coil 9 and the high-frequency choke coils 12a and 12b is connected to at least one between the a and the cathode of the DC power supply 10 for the defogger.

In the glass antenna device for an automobile shown in FIG. 1, a choke coil 9 and high-frequency choke coils 12a and 12b are connected between bus bars 5a and 5b and a DC power supply 10 for defogger, and the choke coils are formed in a high-frequency band. 9 and the high-frequency choke coils 12a and 12b, the DC current from the DC power supply 10 to the defogger flows, but the current in the broadcast frequency band is cut off.

In this manner, the defogger can be insulated from the vehicle body ground at a high frequency by the choke coil 9 and the high-frequency choke coils 12a and 12b. It can be prevented from flowing to the ground, and this received current can be sent to the tuner without leakage.

In the case where only the MW band and the LW band are received, the high frequency choke coils 12a and 12b are usually unnecessary, and only the choke coil 9 is required, and only the high frequency band such as the FM broadcast band is received. If so, only the high-frequency choke coils 12a and 12b may be used. Also, MW
Band, LW band, FM broadcasting band, TV VHF band and TV U
Even in the case of receiving the entire HF band, if there is a coil that satisfies both functions of the choke coil 9 and the high-frequency choke coils 12a and 12b, only such a coil may be used.
Further, when the capacitive coupling is not performed, the choke coil 9 and the high-frequency choke coils 12a and 12b are unnecessary.

In FIG. 1, the position of the glass plate on which the antenna conductor 6 is provided may be anywhere in the upper, lower, left and right margins from the defogger of the rear glass plate 1, and is limited to the position shown in FIG. Not done.

In FIG. 1, the feeding points 4a and 4b are provided separately on the left and right peripheral portions of the rear window glass plate 1. However, the present invention is not limited to this, and the feeding point 4a and the feeding point 4b may be arranged close to each other.
The power supply point 4b may be combined with the power supply point 4b to form a single power supply point, or may be disposed at any position on the rear window glass plate 1.

In the present invention, the window glass plate provided with the antenna conductor is not limited to the rear window glass plate, but may be a side window glass plate, a front window glass plate, a roof window glass plate, or the like. The defogger may not be provided on the window glass plate on which the conductor is provided.

FIGS. 2 and 3 show the construction of another type of glass antenna device for a vehicle different from that of FIG. In FIG. 2, the second antenna conductor 61 is provided between the upper and lower two elements of the antenna conductor 6 of FIG. 1, and connects the output of the first filter circuit 7 and the second antenna conductor 61. . The second antenna conductor 61 receives a second reception frequency band higher than the first reception frequency band or a third reception frequency band higher than the first reception frequency band.

In FIG. 3, the antenna conductor 6 is not provided and a defogger is used as an antenna instead of the antenna conductor 6. A second antenna conductor 61 is provided on the rear window glass plate to output the output of the first filter circuit 7. And the second antenna conductor 61 are connected.

[0028]

DESCRIPTION OF THE PREFERRED EMBODIMENTS "Example 1 (embodiment)" For the purpose of receiving MW band, TV VHF band and TV UHF band, an automobile glass antenna device as shown in FIG. Made. The dimensions and constants of each part were as follows. Table 1 shows the frequency-sensitivity characteristics.

Approximate lateral dimension of the antenna conductor 6: 100
0 mm, interval between two upper and lower elements of the antenna conductor 6: 150 mm, feeding points 4a, 4b (horizontal x vertical): 12 m
m × 25 mm, coil 7a: 2.7 μH, capacitor 1
7a: 20 pF.

Example 2 (Comparative Example) For the purpose of receiving signals in the MW band, a vehicle glass antenna device as shown in FIG. 4 was manufactured using a rear window glass plate of the vehicle. The dimensions of the antenna conductor 6 are exactly the same as in Example 1. Table 1 shows the frequency-sensitivity characteristics.

Example 3 (Embodiment) For the purpose of receiving MW band, FM band, TV VHF band and TV UHF band, a vehicle window glass plate as shown in FIG. The device was built. The dimensions of the second antenna conductor 61 were as follows, and the dimensions and constants of each part other than the second antenna conductor 61 were exactly the same as in Example 1. Table 1 shows the frequency-sensitivity characteristics. The substantially horizontal dimension of the second antenna conductor 61: 650 mm, and the substantially vertical dimension of the second antenna conductor 61: 100 mm.

Example 4 (Comparative Example) For the purpose of receiving television VHF band and television UHF band, an automobile glass antenna device as shown in FIG. 5 was manufactured using a rear window glass plate of an automobile. The dimensions of the antenna conductor 6 were exactly the same as in Example 1. Table 1 shows the frequency-sensitivity characteristics.

Example 5 (Comparative Example) MW band, TV VHF
A glass antenna device for a vehicle as shown in FIG. 6 was manufactured using a rear window glass plate of a vehicle for the purpose of receiving a band and a television UHF band. The dimensions of the antenna conductor 6 were exactly the same as in Example 1. Table 1 shows the frequency-sensitivity characteristics.

[0034]

[Table 1]

[0035]

According to the present invention, even if a plurality of feed points are provided on the antenna conductor, the sensitivity is not deteriorated and one antenna conductor can be used for receiving a plurality of broadcast bands. Therefore, it is not necessary to provide another antenna conductor other than the antenna conductor on the windowpane, and even when the space of the windowpane is narrow, the glass antenna provided on this windowpane can receive a plurality of broadcast bands. Can be used effectively.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of one embodiment of a glass antenna device for an automobile of the present invention.

FIG. 2 is a configuration diagram of another embodiment of the glass antenna device for a vehicle according to the present invention.

FIG. 3 is a configuration diagram of another embodiment of the glass antenna device for an automobile of the present invention.

FIG. 4 is a configuration diagram of a glass antenna device for a vehicle according to a second comparative example, which is a comparative example.

FIG. 5 is a comparative example, and is a configuration diagram of a glass antenna device for an automobile of Example 4.

6 is a comparative example, and is a configuration diagram of a glass antenna device for an automobile of Example 5. FIG.

[Explanation of symbols]

 1: Rear window glass plate of automobile 2: Heater wire 3: Defogger 4a: First feeding point 4b: Second feeding point 5a, 5b: Bus bar 6: Antenna conductor 7: First filter circuit 7a: Coil 8: Reactance circuit 9: choke coil 10: DC power supply 11: capacitor 12a, 12b: high-frequency choke coil 17: second filter circuit 17a: capacitor 20: arrow indicating first tuner side 21: arrow indicating second tuner side 25a: First coaxial cable 25b: Second coaxial cable

Claims (3)

[Claims] An antenna having a first feeding point for receiving a first receiving frequency band and a second feeding point for receiving a second receiving frequency band higher than the first receiving frequency band. A conductor is provided on a window glass plate of an automobile, receives a first reception frequency band and a second reception frequency band by an antenna conductor, sends a reception signal at a first feeding point to a first tuner, A glass antenna device for an automobile for sending a reception signal at a second feeding point to a second tuner, characterized by having a connection structure of one or both of the following (A) and (B): Glass antenna device for automobiles. (A) A first filter circuit is provided between a first feeding point and a first tuner for passing a reception signal in a first reception frequency band and attenuating or blocking a reception signal in a second reception frequency band. Connected connection structure. (B) a second filter circuit between the second feeding point and the second tuner, for passing a received signal in the second received frequency band and attenuating or blocking a received signal in the first received frequency band; Connected connection structure. 2. When the antenna conductor is a first antenna conductor, a second antenna conductor having a third feeding point is provided on the window glass plate separately from the first antenna conductor. Is used for receiving the first reception frequency band, receiving the second reception frequency band, or receiving the third reception frequency band higher than the first reception frequency band. 2. The glass antenna device for an automobile according to claim 1, which has the connection structure of D). (C) A connection structure in which the third feeding point and the output of the first filter circuit are connected. (D) A connection structure in which the third feeding point and the output of the second filter circuit are connected. 3. A power supply type defogger having a heater wire and a bus bar for supplying power to the heater wire is provided on the rear window glass plate, and a DC power supply for the bus bar and the defogger is provided. 3. The glass antenna device for a vehicle according to claim 1, wherein a choke coil is connected between the two, and the antenna conductor and the defogger are capacitively coupled. 4.