JPS60801B2 - automotive glass antenna - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a glass antenna for an automobile in which a heating conductive wire provided on the rear window glass of the automobile also serves as an antenna.

Conventionally, a plurality of heating conductive wires are provided on the rear window glass of an automobile, and in so-called cloud-proof glass, the heating conductive wires are heated to prevent the glass from fogging. A glass antenna for an automobile is known in which an antenna wire is provided horizontally in the remaining portion of the plate glass above the heating conductive wire, and the heating conductive wire and the antenna wire are directly connected by a lead conductive wire.

This type of glass antenna is installed at a position as high as possible from the ground, that is, in the remaining part of the plate glass above the heating conductive wire. In addition, the antenna wire acts as a receiving antenna, and the gain can be improved compared to receiving with the heating conductive wire alone. The conductive wire acts as an antenna and can provide relatively good reception. However, when trying to receive ultra-high frequency band radio waves with the conventional glass antenna described above, it is difficult to use it for practical use over the entire frequency band. No gain is obtained, and no uniform gain is obtained within this band, so even if it is possible to receive ultra-high frequency radio waves of a certain frequency, it is not possible to receive ultra-high frequency radio waves of other frequencies.

The drawback was that the so-called frequency characteristics did not have broadband characteristics. This invention was made in order to eliminate the above-mentioned drawbacks, and a third auxiliary antenna wire is provided in addition to the antenna wire provided horizontally above the heating conductive wire. On the other hand, it is designed to obtain a higher reception gain.

The present invention will be explained below based on the drawings. FIG. 1 shows an embodiment of the present invention, in which 1 is a car window glass;
2 is a heating conductive wire and a first wire provided on the surface of the window glass 1.
(hereinafter simply referred to as the first receiving antenna)
``It consists of a plurality of heating conducting wires 3 installed horizontally at predetermined intervals, and bus bars 4, 4' to which both ends of these are connected.

The bus bar 4 is grounded via a high frequency choke coil 5, and the bus bar 4' is grounded via a high frequency choke coil 5' and a heating power source 6. 7 is a second receiving antenna, which is placed on the surface of the window glass and above the first receiving antenna 2.
It is installed horizontally in the upper part of the

Reference numeral 8 denotes a feeder wire extraction end, which is provided at the end of the lead conductive wire 9, and is connected to the first receiving antenna 2 by the lead conductive wire 9.
and a second receiving antenna 7 are connected. A third receiving antenna 10 is provided in the middle of this lead conductive wire 9. The third receiving antenna 10 is composed of horizontal parts 11, 11' which extend horizontally and are cross-connected to the lead conductive wires 9, and folded parts 12, 12' at both ends. 13 is a feeder line, which is connected to the feeder line outlet 8 and is connected to the first feeder line 8;
- The high frequency current induced by each of the third receiving antennas 2, 7, 101 is guided to the receiver.

The first to third receiving antennas 2, 7, 10 and the lead conductive wires 9 are formed by printing and baking a conductive paste onto the surface of the window glass.

In the above configuration, the high-frequency current induced by each receiving antenna 2, 7, 10' is not grounded to the heating power source 6 side by the high-frequency choke coil 5.5', but is placed in a floating state in terms of high frequency. Reception is performed.

That is, the first receiving antenna 2 functions as a receiving antenna that receives AM and FM broadcast waves. The second receiving antenna 7 acts as a receiving antenna for receiving FM broadcast radio waves (the second receiving antenna 7 does not substantially act as an AM antenna), and is attached to the upper part of the window glass of the first receiving antenna 2. It is possible to increase the effective height and improve the gain. The third receiving antenna 10 has horizontal parts 11, 11' and folded parts 12, 12'.
and a first and a second receiving antenna 2, 7.
As described above, the glass antenna shown in FIG. 1 according to the present invention, which is provided with the third receiving antenna 10, has the same function and effect as the conventional glass antenna for automobiles shown in FIG. 5. When compared, the results shown in Figure 2 were obtained. Figure 2 is a frequency characteristic diagram in which the FM band frequency is plotted on the rattan axis, and the antenna gain is plotted on the vertical axis based on the output of a whip antenna with a length of 1. Broken line 1 is the conventional example shown in Figure 5; These are the characteristics of the glass antenna for automobiles invented by Yoko Kawa.

In the conventional example shown in FIG. 5, 21 is a heating conductive wire and AM,
This is a receiving antenna for M broadcasting, and 22 is a receiving antenna for FM broadcasting. As shown by the broken line 1 in FIG. 2, such a subsidiary glass antenna for automobiles has significant differences in antenna gain for each frequency, and its characteristics are not flat. However, according to this invention, the characteristics are uniform over a wide frequency range as shown by the broken line in Figure 2, and the gain is significantly higher overall for each frequency than the conventional example. That is, the difference between the broken line D according to the present invention and the conventional broken line 1 in FIG.
．． A difference of 3 decibels appears. The reason for this is not fully understood, but the third receiving antenna 1
0' This is thought to be because the third receiving antenna 10 resonates in the frequency region where the gain is depressed, as shown by broken line 1 in FIG. In the example shown, the dimensions of each part of the third receiving antenna 10 to obtain good reception were determined as shown in FIG. That is, the distance h between the horizontal parts 11, 11' and the folded parts 12, 12' is on the 15 to 25 side, and the total length of the horizontal parts 11, 11' and the folded parts 12, 12' is 1.
is 1400 to 190 m, the distance d between both ends of the folded parts 12 and 12' is 10 to 4 m, and these are the lead conductive wires 9
It is symmetrical to Then, from among these numerical ranges, the optimum one is selected depending on the mounting condition, shape, and dimensions of the window glass 1 or the size of the first receiving antenna 2. ``If the distance d between both ends is not set to a certain length or more, the function as the third receiving antenna will be insufficient.
FIG. 4 shows another embodiment of the invention, which differs from the embodiment shown in FIG. 1 in the shape of the third receiving antenna 10. In FIG.

That is, in this embodiment, the folded portions 12, 12' are folded back downward. In this embodiment as well, the same effects as in the embodiment shown in FIG. 1 were obtained. In addition, the first to third
The receiving antennas 2, 7, 10 and lead conductive wires 9 are:
In addition to printing and glazing with conductive paste, it may also be formed by embedding metal pongee wire into a laminated window glass made of two sheets of glass.

As explained in detail above, the present invention directly connects the heating conductive wire/first receiving antenna and the second receiving antenna provided above with a lead conductive wire, and crosses the lead conductive wire. Since it is constructed with a third receiving antenna consisting of a horizontal part that is connected and extends horizontally, and a folded part whose both ends are folded back, there is an advantage that the overall gain can be improved and a wider band can be achieved.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of the configuration including a circuit showing an embodiment of the present invention. FIG. 2 is a frequency characteristic diagram of an embodiment of the present invention and a conventional glass antenna for automobiles. FIG. FIG. 4 is a diagram for explaining an example of dimensions of a receiving antenna, FIG. 4 is a schematic diagram showing another embodiment of the present invention, and FIG. 5 is a diagram schematically depicting a conventional glass antenna for automobiles. Window glass, 2 is a heating conductive wire and first receiving antenna, 5 and 5' are high frequency choke coils, 6 is a heating power source, 7 is a second receiving antenna, 8 is a feeder wire outlet, 9 is a conductive lead line, odor 0 is the third receiving antenna, 1
1 and 11' are horizontal parts, and 12 and 12' are folded parts. Figure 1 Figure 3 Figure 2 Figure 4 Figure 5

Claims (1)

[Claims] 1. A heating conductive wire/first receiving antenna provided in the heated area on the surface of an automobile window glass, and a heating conductive wire/first receiving antenna provided horizontally in the excess portion of the window glass above the heating conductive wire/first receiving antenna. a second receiving antenna that is cross-connected to a lead conductive wire having one end directly connected to the heating conductive wire and the first receiving antenna and a feeder wire extraction end provided at the other end; A third receiving antenna is provided between the receiving antenna and the second receiving antenna, and has a horizontal portion that is cross-connected to the lead conductive wire and extends in the horizontal direction, and a third receiving antenna that has a folded portion formed by folding back both ends of the horizontal portion. A glass antenna for automobiles.