JPS5870645A - Receiver for car - Google Patents

Abstract

PURPOSE:To perform the directive diversity reception by providing the antenna elements on upper or lower parts of a heating conductor wire group on a front window glass of a car, and utilizing the difference of the directivity of reception outputs given from two different points of antenna elements. CONSTITUTION:Antenna elements 10 are provided at the upper or lowr part of a heating conductor group 2 of a front window glass 1 and the reception outputs are picked up from feeding points 12 and 14. Since signals have a different angular position each other corresponding to the dip point of the directivity can be obtained from the feeding points 12 and 14, signals from the feeding points can be switched for better reception at an antenna switching circuit 17.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a receiving device using a glass antenna for radio reception, etc. provided on the window glass of an automobile, and is most suitable for use in a receiving system of a diversity receiving method.

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 multipath distortion occurs due to movement of the receiving point. The quality of the received sound is likely to deteriorate due to factors such as time fluctuations, and in particular, the receiver may hear a "dry sound" in short intervals, making it difficult for the receiver to recognize the received content.

The present invention provides a receiving system that solves this problem, and in particular utilizes the difference in directivity of the receiving output derived from two different points of one antenna line to achieve homology diversity reception. It was designed to do this.

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

In the present invention, the antenna wire is attached to the upper or lower part of the group of heating conductive wires attached to the surface of the rear window glass of an automobile, and the received output is derived from two different points on the antenna wire. The directional characteristics and gains of the reception outputs are made different to effectively perform diversity reception.

sl! FIG. 1 is a front view and an electric circuit diagram of a rear window glass of an automobile showing an embodiment of s1!1 of the present invention. The rear window glass (1) of the automobile shown in Figure 1 has a heating conductor 1 to prevent fogging! A group of striae (2) is provided, these its
A heating current is passed through the group of wires from the battery (3) through the switch (4) and the bus bar (51 (6)).The group of conductive wires for heating (2) is connected to the ground point in the high frequency band i. A T-choke coil (8), which exhibits extremely high impedance in the radio frequency band, is inserted into the pair of feeder lines to keep the noise from entering the feeder line.A battery (3) is also inserted to prevent noise on the feeder line from being mixed into the received signal. ) A decoupling capacitor (9) is inserted between the output line and the ground point.

In addition, the heating conductor [1! In addition to the pattern shown in Fig. 1, the strip group (2) is formed by dividing the bus bar (5) into upper and lower halves, for example, as shown in other embodiments, and connecting these feeder lines in a U-shape. Patterns can be used.

The upper part of the heating conductive wire group (2) is the antenna wire θ.
Q is provided. This antenna wire has a pattern that looks like a single straight line folded multiple times, and an inverted T-shaped auxiliary element facing the heating conductive wire group (2) is provided at the bottom of the pattern. There is. The received output is derived from four antenna wires (feeding point 03 Q4) from two different points of antenna wire 101.

In the pattern shown in the m1 diagram, one output is derived from the folded part at the top of the antenna line <101 to the feed point a3 on the -1000 side of the window glass (1), and another output is output from the folded part at the next stage. The output is led out to the feeding point I on the other side of the window glass (11).By making the two output extraction positions from one antenna pattern different from each other in this way, the dip point of the directional characteristic can be determined. It is possible to easily obtain reception signals with different angular positions.Therefore, even if the reception output of 10000 decreases at the dip point of the directional characteristic due to the direction of the car (10,000 angles), the reception output of the other one decreases due to heat. By performing diversity reception by switching to , it is possible to obtain reception directivity characteristics with fewer dips.

The output of the first feed point is led out to the changeover switch circuit αn via the preamplifier (131).
The output of No. 4 goes through the preamplifier aS and then goes to the selector switch. The switch circuit a'7) is operated by a control signal, which will be described later, in order to minimize the influence of periodic fluctuations in fading or multipath distortion, which are caused by the moving source of the receiving point when the car is running, on the received sound quality. It can be switched to the side of 10,000 or 10,000 good antenna output. The received signal selected by the switch circuit αη is supplied to the FM receiver 1. In addition, the AM reception output is transmitted from the -10,000 feed point I to the preamplifier (1,000
61 and further sent to the AM receiver.

You may also adjust the gain of the preamplifier a■9 so that the two input levels on the switch circuit surface are approximately equal.
Also, as shown in Modified Example 1 of FIG. 2, the reception output of -10,000 is level 1 in the attenuator α frame! The signal may be supplied to the switch circuit Q7) after being adjusted, and then supplied to the receiving circuit via the preamplifier (2). Note that the AM reception output may be enhanced by coupling the antenna wire αQ and the heating conductive wire group (2) in a high frequency manner as described below on the 0)% flow side. 1 is a block circuit diagram of an FM receiver used in a receiving system. In FIG. 6, the reception signal C obtained from the feed point 0304) is selected by the changeover switch circuit Qη also shown in FIG. and IF circuit CI!41 B: j, r
The received signal, which has undergone tuning amplification, intermediate frequency conversion, and FM detection, is supplied to the multiplexer @ via the high-frequency cut control filter C51 and the noise plunker (2), where it is stereo demodulated to the R channel and the L channel. The audio power amplification signal S is derived from the output terminal of the channel. Note that a control signal C such as an automatic stereo/mono switch signal is applied to the multiplexer from the IP circuit c241.

In the front end and IF circuit (241), detection of the received signal level (level detection of IF ratio output or detection output) is performed in order to mute detuning noise between stations, and the received level is constant and the level is The detection output is muted when the received signal level drops to .This received signal level detection signal a is given to the mute drive circuit in the IF circuit (2) and is also sent to the automatic level setting circuit @.This automatic level The setting circuit (A) has a function of changing the threshold of the switching input level according to the switching frequency of the switch circuit αη, and generates a detection signal S when the level is below this threshold.This detection signal S is the antenna It is sent to the switching control circuit (to), where the clock generator -
A switching pulse d is formed in synchronization with a clock G of about 100 KHz outputted by the switching pulse d. This switching pulse d is applied to the trigger input of the T-type flip-flop 6υ, thereby inverting the output (Q%Q) of the flip-flop 6υ.

The Q output and the mutual voltage of the flip-flop 0υ are used as switching control signals of the switch circuit αD.
2 received signal level has fallen below the set standard value.
The flip-flop C1tl is inverted and its Q output goes low, and the output Qltl goes high and the second
The reception output on the feed point side can be switched to 10,000. flip 7
The output power (0 supply) is also given to the automatic level setting circuit, and this circuit detects a drop in the reception level at the feed point OI.
The operating mode can be switched as desired. Therefore, the next time the reception level at the feed point α drops below the set reference level, the automatic level setting circuit (c) detects this, and based on the detected output, the antenna switching control circuit generates the switching pulse d again. The pulse d inverts the flip-flop 7'('lυ). Therefore, the switch circuit (I7) is switched to either side of the first feed point 0.

As a result, tie-versity reception is performed in which the antenna output is always switched to a higher antenna output than the set level of the reception level.

Furthermore, in the T embodiment shown in FIG. 3, variations in multipath distortion are detected and reception can be performed by switching to a reception output method with less distortion. Dinawahe front end and I
The output of P times is also supplied to a 19 KHz bandpass filter (3af), where a stereo pilot signal is extracted. This pilot signal is given to a level fluctuation detection circuit □□□.

If the received signal is distorted by multipath, the pilot signal will also be distorted, so by detecting the level fluctuation (variation in distortion component), the increase or decrease in multipath distortion due to movement of the receiving point can be detected. I can do that.

When the multipath distortion increases by more than a certain amount, the output e of the level fluctuation detection circuit (c) operates the high-frequency cut control filter track, and the high-frequency distortion component of the detection output is cut off and given to the multiplexer (5). It will be done.

At the same time, the output e of the level fluctuation detection circuit (c) is also sent to the antenna switching control circuit (to), and the switching pulse d is formed as described above, and the other signal is output as in the case of reception level fluctuation. Switched to receive output. As a result, a received signal with less multipath distortion can be obtained. In the antenna switching control circuit 00), a switching pulse d is generated when there is an input of 10,000 of any one of the outputs of the automatic level setting circuit (c) and the level fluctuation detection circuit (to). In other words, the switching pulse d is created by OR logic with the signal 1 and e. In addition, the front end and IF circuit c! The reception level detection signal a obtained from the current signal is applied to the antenna switching control circuit axis as an operation prohibition signal, thereby inhibiting the formation of a switching pulse d in the weak electric field between stations during channel selection.

According to the T embodiment shown in FIGS. 1 and 3, even if a fading wave occurs due to periodic fluctuations in multipath distortion due to movement of the receiving point when the car is running, the two output extraction positions at can be interchanged. Since the reception level fluctuation status and the angular position of the dip point of the directional characteristics can be set to differ from each other, selecting one of the better reception outputs can eliminate the influence that may affect the received sound quality. can be minimized.

4 to 60 show modified examples of the first and second antenna patterns. FIG. 4 shows a front view of the window glass. The H strip group (2) is formed in a U-shaped pattern, and the heating conductive wire groups above and below it are short-circuited at the bus bar (6), and are supplied with I through the bus bars (5) and (7).
I and antenna wire Q (l is the main antenna (IQa) in which six wires are connected in an E-shape, the bent 1lffl (10b) connected to the uppermost wire, and the main antenna (10a). ) connected to one of the top tuning points of the main antenna. (10a) connects to the upper heating conductive strip group (2) to enhance the reception level.The reception output is It is derived from the side of the feed point C1? For example, the lengths of the lead wires connected to the preamplifier (131051f) can be made the same, and the factors that change the damage characteristics in parts other than the antenna fibers can be equally distributed.

In FIGS. 5 to 12, the coupling between the antenna wire Qtll and the heating conductor wire group (2) is loose. In addition, in FIGS. 9 to 12, an antenna wire (101) is provided at the lower part of the heating groove '#IL attachment (2).

In Figure 5, two loop antennas (10a x 10b
) and a single element (10C) constitutes an antenna wire (IQ), its central conductor is connected to the feeding point α31, and a second output is fed from the side of the loop antenna (10a).
It is led out to the electrical point (14).

In FIG. 6, the antenna wire (11) is composed of a loop-shaped antenna (10a) and six parallel single elements (10b) to (10d), and the central conductor and the loop-shaped antenna (10a) 9Il1 The first and second Tagata are derived from the feeding point a'a (+41. Feeding point (12) (
14) is located close to the corner plate at the top of the window glass (1) f1
3, feeder lines are routed from the antenna pattern to these feeding points.

In FIG. 7, a U-shaped antenna (10a) and a single element (
10b) and the stub (10) that connects these, the antenna wire is constructed of a wire, and the output from the central part of the single element (1ob) and the side part of the U-shaped antenna (10a) is connected to the feeding point. (121 and ■l are derived.

In Fig. 8, the waveform 1 is connected as if bent
Antenna line a with book horizontal elements (102) to (10d)
θ is S, and the first and second outputs are derived from the coupling portion of each horizontal element to the feed point 020.

In FIG. 9, four horizontal elements (10a) to (10d) and a single element (10
e) An antenna wire Q(l is constructed, and the outputs of the first and second wires are fed from the coupling part of each horizontal element to the feeding point 03 (1
4).

In FIG. 10, an antenna wire (]0) is composed of a single element (10a) and loop antennas (10b) and (10c) placed above and below it, and the @ part of the central conductor and antenna (10C) Outputs are derived from the respective feed points tlH4).

i'+411 IN, antenna leg 00) or shape 5, which is the pattern in Figure 4 reversed inside out! In the 124th loop antenna (10a),
An antenna strip (101) is constituted by a semi-folded dipole antenna (10b) and a single cord (10C) coupled in phase matching to the dipole-like antenna, and a loop-shaped antenna (IDa) and a "dipole-like" The first and second (7) outputs are led out from the side of the antenna (10b) to the feed point tea circle.

Figures 13 to 30 are examples of direct coupling or capacitive coupling between the antenna strip (11) and the heating conductor group (2). Figure 18~
In Fig. 21, the conductor III wire +21 (D center and C phase matching point heat antenna wire -(7) -@ are connected,
In Fig. 15 and Fig. 17, both are coupled via a matching element (21+).

In FIG. 13, the antenna wire QO1 is constituted by a wire (10a) bent into a waveform and a cable (10b) connected to the center of the lower stage, Two outputs are derived from the feed point 03C14). Main cord (10b) and heating conductive wire group <2)
The WLG windows (11 and 11) are connected to each other at a distance away from the center of the window glass (11).

In FIG. 14, an antenna line Q (1) is composed of a bow-shaped antenna (10a), a rape-shaped antenna (10b), and a single element (10C), and a U-shaped antenna (1
The center of the lower stage of 0a) is connected to the heating conductive wire #+21 with a force S. The output is from the center conductor and U-shaped antenna (
10a) to the feed points (121 (14)
f is derivedG).

In FIG. 15, a turn θ antenna wire 01) which is almost the same as that in FIG. They are coupled via a matching element Qυ. Also, in Fig. 16, C ma, almost the same pattern as Fig. 7 Q) Antenna wire 0 ■ Force 1
The U-shaped parallel line antenna (1ea
) and a group of heating conductive wires (2) are connected to each other at a centerline position of 1μ of the window glass (1).

In FIG. 17, a folded antenna line (lot) similar to that in FIG. 8 is formed, and the lower horizontal element (10d)
and the conductors ii and i group (2) are coupled to each other via a matching element (21). Further, in FIG. 18, antenna wires 001 having substantially the same pattern as in FIG. 9 are formed.

The single element (10e) on the top, the heating groove W, and the group of filaments (
It is combined with 21 and becomes 0.

In Figure #J19, antenna wires (II) are formed with almost the same pattern as in Figure 10, and the central conductor wire is connected to the group of heating conductive wires (2). Antenna filament 00) with almost the same pattern is formed,
The connecting portion of the Y-shaped antenna (10a) and the bus bar (51) of the group of heating conductive wires (2) are coupled.

In Fig. 21, the antenna wire has almost the same pattern as in Fig. 12. and the upper single element (10
C) and heating conductive wire group (2).

Figures 22 to 30 show examples of capacitive coupling. In Figure 22, the antenna wire Q (
% was formed and placed close to the lower single element (10b) and heating conductive wire group +21.

A single element 2z is connected to achieve capacitive coupling between the antenna wire 00) and the conductive wire group (2).

@ In Figure 26, the antenna wire 0 has almost the same pattern as in Figure 14, and the heating conductor 11L wire group (2) and capacitance are connected through the single-layer wire as in Figure 22. combined. In Fig. 24, the antenna wire α0) or fi3E2 has almost the same pattern as Fig. 6 or Fig. 15, and the lower loop-shaped antenna (10a) and the single element are connected through the coupling element. Furthermore, the single element (a) and the heating groove 1 are capacitively coupled to the wire group (2).

In FIG. 8B25, an antenna wire QO1 having substantially the same pattern as in FIG. 7 or FIG. 16 is formed and is coupled to the guide if wire group (2) via a single element. In the 26th factor, an antenna wire a9 having a waveform pattern that is almost the same as that in the 8th factor or in FIG. 1! In Fig. 27, the Q capacitively coupled with the wire group (2) is formed with antenna wires (1 (e)) having almost the same pattern as in Fig. 9 or @18,
It is capacitively coupled to the heating conductor #L wire group (2) via 2. In FIG. 28, an antenna line 0I having almost the same pattern as in FIG. 11 or FIG. ) to the heating conductor 11L wire group (
Capacitive coupling is achieved with 21.

In FIG. 29, an antenna wire OQI having almost the same pattern as in FIG. 10 or FIG. 19 is formed, and a single-element device is connected to the central conductor for capacitive coupling. 6th
In FIG. 0, an antenna wire QOI having almost the same pattern as in FIG.

By selecting the positions of the points, it is possible to easily obtain reception outputs in which the variation of the reception level and the angular position of the dip point of the directivity characteristics are different from each other. Therefore, even if there are fluctuations in the reception level due to movement of the reception point (fading, etc.) or changes in the direction of the reception signal, the diversity reception selects the best reception output. can be carried out extremely effectively, thus achieving high quality reception with reduced shadows caused by reception level fluctuations.
You can get the number.

[Brief explanation of the drawing]

FIG. 1 is a front view of a rear window glass of an automobile showing one embodiment of the present invention and a circuit diagram of a receiving system, and FIG.
FIG. 6 is a circuit diagram of an FM receiver used in the reception system F of the present invention, and FIGS. 4 to 30 are modifications of the antenna wire pattern, respectively. It is a front view of the rear window glass which shows an example. In addition, (1)・・・・・・・・・・・・Rear window glass (
2)・・・・・・・・・・・・Heating conductive wire group 00)・・・・・・・・・・・・Antenna wire 0
'& 4)......Feeding point αη...
.........Choice switch circuit (28)...
・・・・・・・・・・・・Automatic level setting circuit
・・・・・・・・・・・・Antenna switching control circuit. Agent Souvenir Katsu Tokukai 1970-1970 5 (6) Figure 3-

Claims (1)

[Claims] A heating conductive wire group attached to the surface of the rear window glass of a vehicle, an antenna wire attached to the upper or lower part of this heating conductive wire group, and two different antenna wires. wJl derived from the point and a second output terminal, a means for detecting the radio wave reception state of the first and @2 output terminals, and a means for detecting the radio wave reception state of the first and second output terminals, and a A receiving device for an automobile, comprising a changeover switch means for selecting and receiving an output from an output terminal of the vehicle.