JPS58196702A - Glass antenna for motorcar - Google Patents

Abstract

PURPOSE:To obtain a received tone with less variation of reception characteristics with the moving direction of a monorcar by using two antenna patterns which are different in directivity in combination effectively for directional diversity reception. CONSTITUTION:The 1st antenna wire 13 for FM reception is provided over a header line 2 provided on a rear window glass 1 for defogging. Further, the 2nd antenna wire 22 consisting of an antenna wire 23a arranged closely along the heater line 2 and three parallel wires 23b, 23c, and 23d coupled as if one straight line were bent while one end of the lowermost antenna wire 23b is connected to the middle point of the antenna wire 23a is provided under the heater line 2 for diversity reception. The outputs of the antenna wires 13 and 22 are led to a switch circuit 20, which selects and supplies the received signal of one antenna line having an excellent reception state to an FM tuner on the basis of a selection signal S.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a glass antenna for automobiles constituting a privacy reception system.

When a moving car receives radio waves such as FM broadcasts, periodic fading occurs due to fluctuations in the field strength of the received radio waves in the direction of travel, and time fluctuations in multipath distortion occur as the receiving point moves. The received sound quality is likely to deteriorate due to such causes, and in particular, the received sound may be interrupted in short intervals, making it difficult to recognize the received content.

The present invention provides a receiving system that can solve this problem, and in particular, allows directional diversity reception to be performed by effectively combining two antenna patterns with different directional characteristics.

Embodiments of the present invention will be described below with reference to the drawings.

#! FIG. 1 is a front view and an electric circuit diagram of a rear window glass of an automobile showing one embodiment of the present invention. The rear window glass +1) in Figure 1 has many heaters a(
2) are provided, and these heater wires (2) are divided into upper and lower two groups, batch IJ-(31 to mother 1!(41
(53 (A heating current is passed through 61.Heating current f
An AJIII wave choke edge yoke coil I is inserted into the pair of power feeders 11 (7) and (8) that supply Lf in order to float the heater wire from the grounding point in the tz+1iI8b frequency band, and the hot side power feeder wire (7) is is connected to a decoupling capacitor aυ for noise removal.

In addition, the heater @ (2+ is not divided into two groups, but the bus line (41
Common f61, mother 1! 141 (61 and bus line (5
) may be a power supply method in which a heating current is passed between the

heater! ! (A first antenna line Q field for FM reception is provided on the upper part of 2+.This antenna line 0
1 is a horizontal line (14a) (14b) in six upper and lower stages whose ends are joined as if a single piece WA was bent.
The main antenna I consisting of (14C) and this main antenna Q
The antenna is provided with auxiliary antenna wire warmers Qe each consisting of one wire placed at the upper and lower portions of the antenna.

The lower auxiliary antenna oG is provided for the purpose of transmitting the received wave induced from the heater to the main antenna line (14c) and improving the directivity characteristics of the antenna. This auxiliary antenna Qf9 is electrically matched at a position on the center line of the window glass (1), and the main antenna line (1
It is connected with four.

``Also, the upper auxiliary antenna Q9 is attached for the purpose of obtaining omnidirectional characteristics, and is located at a position away from the center layer of the middle main antenna line (14b) via the connecting line aη having a matching effect. The auxiliary antenna O5 and the uppermost main antenna wire (141) are closely opposed to each other over a predetermined distance, so that an inductive coupling between the two is achieved. Directivity has also been improved.

Preferable dimensions of each part of the first antenna wire 03 having the above-described pattern are as shown in the first example and the second example of the table below.

The output of the main antenna wire 03+ is led out from the feeding point side to the switch circuit (2) via the preamplifier 03.

A second antenna wire (c) for diversity reception is provided at the bottom of the heater wire (21).

This second antenna wire ■ is a heater @ (single antenna wire <238. placed close along 2+)
It consists of six horizontal parallel lines (23b), (25C), and (23d) connected as if a single straight line was bent. One end of the lowermost filament (25b) is coupled to the midpoint of the single antenna filament (23M).

WA composed of these filaments (23a) to (23d)
The preferred size range of the antenna wire (221) of No. 2 is as follows.

A=10-70 8 points: Center ±1001 C=25-260 IIr11 C'= 13-40M "": □'D=40
0ζ700M E=3~10■ F=3~20+w L=6 0 0" 1 1 0 0mm The output of the second antenna wire @ is the feed point (2) at one end of the wire (23d)
from the preamplifier to the switch 1gl path (4). The output of the switch circuit 4 is given to an FM tuner, and a receiving state discrimination circuit provided in this tuner selects the output of the first and second antenna wires (13) which has a better receiving state. The selection signal 8 is shaped,
1lill: to be done. Based on this selection signal S, the switch circuit (4) is switched to perform P9TI11 diversity reception.

The antenna filament (131) of a141 and the second antenna have a complementary relationship in terms of directivity, and each has a tip point or a reception indeterminate region at a different angular position.

Figures 1ii2A to 1lt20 are W, 1 and 2nd antenna # * (1; between 14 directional characteristic lines (voltage scale)
%A, H, and C have received wave frequencies of 8Q MH, respectively.
z.

In the case of 84bAH1 and 90MHz, the angle σ is the arrival direction of the radio wave. The dimensions of each part of the first antenna wire on the upper side of the heater wire (2) are those of example #J1 in the table above, and the dimensions of each part of the second antenna wire on the lower side are A.
=30mm, 8 points-midpoint, c'=5 orchid, D-550mm
, F=5M, L=1000m. Other dimensions are set within the preferred ranges described above.

As is clear from FIGS. 2A to 2B, the directivity characteristic (indicated by a dotted line) of the first antenna wire 03 has a dip point M at an angular position of 0@. - The directivity characteristic (indicated by a solid line) of the second antenna wire W4 has an angular region where a dip point or reception level decreases at an angular position of 270°. That is, the first antenna on the upper side has good reception sensitivity for radio waves arriving from a direction almost perpendicular to the direction of travel of the car, and the antenna ls2 on the lower side has good reception sensitivity for radio waves arriving in the direction of travel of the car. The C reception sensitivity is good. Therefore, it is possible to perform tieback reception to compensate for the part where the reception ability of one signal is degraded by the other signal, thereby obtaining received sound with less deterioration due to directional characteristics.

Next, FIG. 3 shows another embodiment in which the pattern of the antenna wire a3 of a141 is changed. The first antenna wire (pattern 13 in this example is %wJ1).One wire (14d) is added between the wires (14b) and (14C) of the main antenna I in the example shown in Fig. It is something.

Six parallel stripes (14b) to (14d) are connected in an E-shape. The auxiliary antennas (15 (11) are the same as the embodiment of ill, but the main antenna wires (14b) and (14C) are arranged above and below the main antenna α fathom, respectively, at different tuning points from the first factor. The pattern of the second antenna line (c) is 1.
It is the same as Figure 81.

1M4 mu diagram~m! Figure 4C shows the first and second antenna wires (13c?21 of 80M) 1g, 84 in Figure 5.
MHz, 9 [Directional characteristic compaction at 3 MHz. Note that the second antenna line exhibiting this characteristic is
The dimensions of each part corresponding to the diagram are A = 30 points, B = midpoint,
""15w, D=600-m%m=5 vm,
F = 5 cabinets, L = 8 [10 cabinets.

@4A4A As shown in Fig. 4C, the antenna pattern of this embodiment also has a tendency for reception sensitivity to decrease with respect to radio waves arriving from the first antenna line I in the direction of travel of the automobile. By supplementing this with the f second antenna line (2), it is possible to obtain a nearly omnidirectional reception output.

Figures 5A and 5B show the reception levels of the first and second antenna lines a3 (c) when a car with the antenna pattern of Figure 3 moves in the same direction and perpendicular direction to the incoming radio waves, respectively. It is a graph showing time fluctuation.

As shown in FIG. 5A, when the car moves in the same direction as the direction in which the radio waves arrive, the second (lower 1I) - antenna c! a
The Ukei level 8 is large as shown by the solid line. On the other hand, the reception level of the first (upper 14i1) antenna a1 is small as shown by the dotted line, and also exhibits unstable reception characteristics such that the reception level changes greatly in short periods as the antenna moves. On the other hand, when the car moves in a direction perpendicular to the direction in which the radio waves arrive, as shown in Figure 5B, the reception levels of the 1s1 and second antennas are almost the same, and the level of the second antenna increases as shown by the solid line. It fluctuates wildly and shows unstable acceptance of 9s%.

As mentioned above, the upper and lower two antennas 03C? Since the reception characteristics of a vary greatly depending on the direction of travel of the car, and one can be compensated for by the other, by performing diversity reception, it is possible to obtain received sound with less variation in reception characteristics depending on the direction of travel of the car. .

Note that as the first (top @) antenna pattern, various patterns can be used in addition to the above-mentioned embodiments. For example, a dipole-like antenna that uses a single horizontal antenna wire and extracts the output from approximately the center, an antenna that combines multiple horizontal wires, and an antenna that is combined with a heater wire (2). etc. can be used.

These known antenna patterns generally have a reduced reception ability for waves arriving in the direction of travel of the vehicle, so the reception characteristics can be improved by diversity reception in combination with the lower group 2 antenna. (2) was installed below the heater 1il (2+) so that it could supplement the reception output of the first antenna (a!) installed above the heater (2). By using diversity reception by switching antennas, it is possible to obtain commercial quality received sound with reduced fluctuations in reception level depending on the direction of travel of the vehicle.

[Brief explanation of drawings]

FIG. 1 is a front view and electrical circuit diagram of a rear window glass of an automobile showing one embodiment of the present invention, and FIGS. 2A to 2C are 80 MHz, 84 MHz, and 99bAH
The first example (upper 11) of FIG. 1 regarding the radio wave of z and! ! 2 (lower side) antenna directional characteristics *rq1., Figure 6 is a front view and electric circuit diagram similar to Figure 1 showing another embodiment of the present invention, and Figures 4A to 4C are summary 6. Figures 5A and 5C are similar to Figures 2A to 2C, which show the same characteristics of antennas 1 and M2 in Figure 3.
Example above) and No. ? (lower) antenna for receiving 4M in different moving directions of the car? It is a graph showing the time fluctuation of the bell. In addition, in the symbols used in the drawings, (1)...... Rear window glass (
2)・・・・・・・・・・・・・・・ Heater wire (I3
・・・・・・・・・・・・・First antenna edge wire・・・・・・・・・・・・・Switch circuit (2)・
.....This is the second antenna line. Agent Souvenir Katsu I Tsune Kao Yoshio l Shun Sugiura Responsibility 6 C Aji Somi

Claims (1)

[Claims] t. A heater wire provided on the rear window glass of an automobile, and a first heater wire provided above and below the heater wire.
and I! 2 antenna, the second antenna having one horizontal strip disposed closely along the heater wire, and a strip connected to approximately the midpoint of the strip. It consists of 6 parallel horizontal stripes that are connected as if they were folded twice, and by connecting the first and j12 antennas to a switch circuit and selecting any one of the 10,000 received signals. . A glass antenna for an automobile, characterized in that the decrease in reception output of the first antenna for at least incoming radio waves in the same direction as the traveling direction of the automobile can be compensated for by the jI2 antenna. 2. The above-mentioned first antenna has a main antenna consisting of six upper and lower parallel lines connected to each other as if a single straight line is bent, and a main antenna arranged above and below the main antenna. Each antenna is provided with an auxiliary antenna consisting of a single wire,
The lower auxiliary antenna line and the lower main antenna line are combined near the vertical center value position of the window glass, and the center line position of the upper auxiliary antenna and the center line of the middle main antenna line are combined. The antenna wires are connected to each other at positions apart from the center line position, and the upper main antenna wire is extended to near the center value with the upper main antenna wire facing the upper auxiliary antenna wire over a predetermined length. An automotive glass antenna according to claim 8, characterized in that: 6. The first antenna has a main antenna consisting of six upper and lower parallel wires connected in a figure-eight shape and a folded portion of the upper wires, and a main antenna on the upper and lower sides of the main antenna. □Equipped with auxiliary antennas each consisting of a single filament, the upper auxiliary antenna and the upper filament of the main antenna are combined, and the lower auxiliary antenna and the lower filament of the main antenna are combined. The automobile according to claim 1, wherein the upper folded portion of the main antenna wire and the upper auxiliary antenna are closely opposed to each other by a predetermined length. glass antenna.