JPH0310404A - Glass antenna for vehicle - Google Patents

Abstract

PURPOSE:To use the antenna for both diversity reception and nondiversity reception by devising the antenna such that a matching device capable of using a synthesis signal of received signals of both antennas as an antenna signal is freely mounted between feeding points of those two antennas having a directivity different from each other. CONSTITUTION:When the antenna is used with a radio receiver provided with a diversity receiving function, two antennas 18, 19 whose directivity differs from each other provided on the same glass pane 17 are directly connected to two input terminals of the receiver side. On the other hand, when the antenna is used with a radio receiver not provided with the diversity receiving function, a matching device (balun) 23 is mounted between feeding pints 20, 21 of those two antennas 18, 19, the reception signal of those two antennas 18, 19 is synthesized and the synthesis signal is is inputted to the radio receiver as the antenna signal. Thus, the glass antenna with the same specification is used for the diversity reception system and the system not employing the diversity reception to attain excellent radio reception.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a glass antenna for a vehicle that can be used for both diversity reception and non-diversity reception.

(Prior Art) Conventionally, as described in, for example, Japanese Utility Model Application Publication No. 58-61505, a main antenna and a sub-antenna with mutually different directivity are installed on the rear glass of a vehicle, and these antennas are adjusted according to the radio wave conditions. A radio reception system is known that selectively selects the reception signal of
It is called a diversity reception system.

By the way, among mass-produced cars, even if they are of the same model, there are cases where some cars adopt a diversity reception system and others do not (non-diversity), depending on the grade. In that case, if you use an antenna with a directivity that has the greatest diversity effect as the main antenna, the reception sensitivity will be extremely poor with non-diversity.Therefore, if you use a glass antenna with diversity and non-diversity, In order to achieve compatibility, it is necessary to use a main antenna with almost no directivity, even if it means sacrificing the diversity effect.Also, to avoid this, two antenna patterns with different antenna patterns must be used.
We will have to make different types of rear glass.

(Object of the Invention) The present invention has been made in view of the above problems, and can be commonly used for both diversity reception systems and non-diversity reception systems. The object of the present invention is to obtain a glass antenna for a vehicle that can obtain good reception sensitivity in any case.

(Structure of the Invention) The present invention enables diversity reception in which two antennas with mutually different directivity are provided on the same glass surface, and reception signals of these two antennas are selectively used. In the glass antenna for a vehicle, a matching box can be freely installed between the feeding points of the two antennas, so that a composite signal of the received signals of both antennas can be used as an antenna signal.

(Function) When the glass antenna of the present invention is used with a radio receiver equipped with a diversity receiving device, the two antennas are directly connected to the two input terminals on the receiver side,
On the other hand, when used with a radio receiver that does not have a diversity receiver, a matching box is installed between the feeding points of the two antennas, the receiving signals of the two antennas are combined by this matching box, and the combined signal is is input to the radio receiver as an antenna signal.

Two antennas with mutually different directivity, one of which is a main antenna with a directivity corresponding to the direction of the polarization plane of radio waves transmitted from a broadcasting station, and the other is a sub antenna that complements the main antenna. and in this case,
When connected to a receiver equipped with a diversity receiving device, the one with higher sensitivity is automatically selected and used among the received signals of these two antennas depending on the radio wave condition. Also,
When connected to a non-guipatity receiver via a matching box, the received signals from the two antennas are combined in a way that does not interfere with each other, and a combined signal with less directivity and greater gain is sent to the radio receiver as an antenna signal. Sent.

(Example) Examples will be described below based on the drawings.

FIG. 1 is an overall view of one embodiment of the present invention. In this embodiment, as an audio set, an audio main body 3 equipped with a die-panty type radio receiver, a CD player, a cassette deck, etc. is disposed on a floor console 2 provided in the front part of the vehicle interior 1. Further, the instrument panel 4 is provided with a woofer amplifier 5 and a pair of left and right front speakers 6.7. Then, on the back of the rear seat 8, there is a pair of adhesives 9. 10 and a woofer amplifier 11 are provided. Furthermore, door speakers 14 and 15 are provided on the left and right rear doors 12 and 13, and a rear control switch 16 is provided in the center of the rear seat 8.

In addition, the rear glass 17 has a main antenna I8 at the top.
is provided, and a sub-antenna 19 is provided at the bottom. These antennas 18 and 19 are constructed of printed wires formed inside the rear glass 17, and their feeding points 20 and 21 are placed close to each other, and the audio is transmitted through the antenna amplifier 22. It is connected to the radio receiver of the main body 3.

The rear glass 17 equipped with the glass antenna consisting of the main antenna 18 and the sub-antenna 19 can also be used as is for vehicles that do not have a diversity receiving device. In that case, as shown in FIG.
Between the feeding points 21 of 9, a variable capacitor C+, a negative side coil L1゜Lo, a secondary side coil, and a capacitor C
Attach a balun 23 consisting of t and C2, and this balun 2
Connect the output end of 3 to the receiver side. At this time, the received signals of both antennas 18 and 19 are shifted by half a wavelength and combined in the balun 23, and the combined signal is used as an antenna signal.

Main antenna above! 8, as shown in Figure 3, has almost no gain in the front side (F) and rear side (R) directions, and exhibits a figure-8 directivity with the axis perpendicular to the front side (F) and rear side (R). There is. Further, the sub-antenna 19 has a directivity that is substantially perpendicular to the main antenna l8, and as shown in FIG. It has been restored. The glass antenna configured by these can maximize the diversity effect by connecting it as it is to the diversity receiving device, and in the case of non-diversity, by attaching the balun 23 as described above, both antennas 18 Since the received signals of .degree. 19 are shifted by half a wavelength and synthesized in a form without directivity, a highly sensitive reception condition can always be obtained.

The feeding point 20 of the main antenna 18 and the feeding point 21 of the sub-antenna 19 are both L-shaped as shown in FIG.
It is glued on the back.

When this glass antenna is used as a diversity reception system, a socket (not shown) on the feeder line side is connected to the feeding point 20, 21 formed in the shape of a plug-in piece as described above. Also, when using this glass antenna for non-diversity, use the balun 2 as described above.
Attach 3.

FIG. 5 shows the state in which this balun 23 is attached.

As shown in FIGS. 5 and 6, the balun 23 has a circuit board 26 printed with a circuit pattern fixed between a pair of casing members 24 and 25 on the front and back sides, and is directly attached to the board 26. The two female collectors 27 and 2B are exposed to the outside through the back casing 25, and the feeder wire 29 is taken out from the front casing 24, and the above-mentioned power feeding point is shaped like a socket and formed in the shape of a plug-in piece. It can be freely attached to 20.21.

FIG. 7 shows another embodiment of the invention. In the case of this embodiment, the structure of the glass antenna itself is similar to that of the previous embodiment, and a main antenna 18 and a sub-antenna 19 are provided on the back side of the rear glass 17.
As a matching device when using this for non-diversity purposes, instead of the balun 23 as described above, a coaxial cable 30 is used, in which the feeder line 29 is branched into a U-shape at the tip.
I try to use This coaxial cable 30 runs from its branch point to the feeding point 20.21 of both antennas 18.19.
By providing a difference in length between the two antennas 18 and 19, the received signals from the two antennas 18 and 19 are transmitted with a phase shift of, for example, half a wavelength. In this case, it is possible to prevent mutual interference of signal waves and perform highly sensitive reception without directivity.

(Effects of the Invention) Since the present invention is configured as described above, good radio reception can be achieved using a glass antenna with the same specifications, even for diversity reception systems and for non-guipanti reception. You can do as you like.

[Brief explanation of the drawing]

Fig. 1 is an overall diagram of an embodiment of the present invention, Fig. 2 is a configuration diagram of the main parts of the embodiment, Fig. 3 is a directivity characteristic diagram of the main antenna in the embodiment, and Fig. 4 is a diagram of the main antenna in the embodiment. A directional characteristic diagram of the sub-antenna, Fig. 5 is a sectional view showing the structure and installation state of the feeding point of the antenna and the matching box in the same embodiment, Fig. 6 is a perspective view of the board and connector of the matching box, and Fig. 7 FIG. 2 is a main part configuration diagram of another embodiment. 17: Rear glass, 18: Main antenna, 19: Sub antenna, 20, 21: Feeding point, 23: Balun, 26:
Board, 27.28: Connector, 29: Feeder wire, 30
·coaxial cable.

Claims (1)

[Claims] (1) In a vehicle glass antenna that enables diversity reception in which two antennas with mutually different directivities are provided on the same glass surface and the received signals of these two antennas are selectively used, A glass antenna for a vehicle, characterized in that a matching device can be freely attached between the feeding points of the two antennas to enable a combined signal of the received signals of both antennas to be used as an antenna signal.