JPH08307133A - High frequency use glass antenna and high frequency use diversity glass antenna - Google Patents

Abstract

PURPOSE: To improve the reception sensitivity of an FM broadcast or a television broadcast by approaching an antenna conductor to both a defogger and a vehicle body opening to apply capacitive coupling of the conductor to them. CONSTITUTION: A heater wire 2 and a power conduction heating defogger 3 having bus bars 5a-5c feeding power to the heater wire 2 are provided on a glass plate 1 of a rear window of an automobile. Furthermore, an antenna conductor 14 is provided on the glass plate 1 of the rear window and a choke coil 9 is inserted between the bus bars 5a-5c and a DC power supply 10 for the defogger 3. Then a connection wire 13 connecting a main element 15 and a sub element 16 of the antenna conductor 14 is provided. In this case, the antenna conductor 14 is a loop form closing the main element 15 in terms of DC via a connection wire 13 extended in nearly lateral directions from a feeding point. The sub element 16 is provided by the main element 15 and the sub element 16 is made close to an opening of a vehicle opening for capacitive coupling.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high frequency glass antenna and a high frequency diversity glass antenna, which are suitable for receiving FM broadcasting, television broadcasting, UHF, etc. and which significantly improve the receiving sensitivity.

[0002]

2. Description of the Related Art Conventionally, a diversity glass antenna for FM broadcast reception as shown in FIG. 4 is known. FIG.
In general, a defogger 3 composed of a heater wire 2 and bus bars 5a, 5b, 5c is provided on a glass plate 1 of a rear window of an automobile, and further, a rear window is provided so as not to interfere with the heater wire 2. The antenna conductor 6 and the antenna conductor 40 are arranged in the upper and lower margins of the glass plate 1.

In addition, the antenna conductor 6 and the antenna conductor 40
The signals received by each are transmitted to the FM amplifier via the coaxial cable. Further, the FM amplifier amplifies the received signal and transmits it to the antenna switching device via the coaxial cable. Further, in the antenna switching device, of the received signals of the antenna conductor 6 or the antenna conductor 40, whichever is stronger is selected and sent to the receiver.

The antenna conductor 40 extends in a substantially lateral direction.
One end of each of the two elements extending substantially in the horizontal direction is connected near the feeding point, and the other end of each of the two elements extending in the substantially horizontal direction is an open end.

The antenna conductor 6 and the antenna conductor 40 are
Both are close to and capacitively coupled to the defogger 3, and the defogger 3 functions as an AM broadcast antenna and an FM broadcast antenna. The antenna conductor 40 was not close to the opening of the vehicle body and was not capacitively coupled. Further, the antenna conductor 6 also functions as an AM broadcast antenna. Therefore, the high frequency choke coils 12a, 12b and AM for insulating the FM broadcast wave from the ground (vehicle body ground)
A choke coil 9 that insulates the broadcast wave from the ground is connected in series and is inserted between the defogger 3 and the ground.

Reference numeral 10 is a battery, and 11 is a capacitor for absorbing noise. In addition, it is a figure other than FIG.
The same numbers and numerals as in FIG. 4 have the same names.

[0007]

However, the receiving sensitivity of the above-described antenna conductor 40 has not been sufficiently obtained. Also, comparing the magnitude of the received signal of the antenna conductor 6 with the magnitude of the received signal of the antenna conductor 40, the signal received by the antenna conductor 6 is usually larger, and the frequency of antenna switching operations by the antenna switching device is low. In many cases, the diver effect was not obtained.

Furthermore, the conventional technique shown in FIG.
Although it is a diversity receiving device that utilizes signal amplification by an amplifier, in the future, there is a tendency to change to a diversity glass antenna receiving device in which the amplifier is removed and a matching circuit for resonance is inserted instead of the FM amplifier. .

Therefore, there is a high probability that the pattern shape of the antenna conductor 40 introduced in the prior art cannot be applied.

Therefore, when the antenna conductor is arranged in the lower space below the defogger of the glass plate of the rear window, it can be used in both a conventional receiver with an amplifier and a receiver without an amplifier expected to be developed in the future. The present invention is applicable.

[0011]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and has an electric heating including a heater wire and a bus bar for supplying power to the heater wire on a glass plate of a rear window of an automobile. A defogger of the formula is provided, and further, a direct current is not transmitted and received between the glass plate of the rear window and the defogger, but a high frequency current is transmitted and received. In a high frequency glass antenna with a pattern antenna conductor and a choke coil inserted between the bus bar and the DC power source for the defogger,
There is provided a high frequency glass antenna, wherein the antenna conductor has a loop-shaped main element and a sub-element in an electrical sense, and the antenna conductor is close to an opening of a vehicle body and capacitively coupled.

Further, according to the present invention, an electrically heated defogger having a heater wire and a bus bar for supplying power to the heater wire is provided on the glass plate of the rear window of the automobile, and the glass plate of the rear window is provided between the defogger and the defogger. DC current is not transmitted and received, but high-frequency current is transmitted and received by providing multiple antenna conductors of a predetermined pattern that are capacitively coupled in close proximity to each other at a predetermined interval and choke between the bus bar and the DC power source for the defogger. A coil is inserted, and at least one of the plurality of antenna conductors has a loop-shaped main element and sub-element in an electrical sense, and the antenna conductor is close to both the defogger and the vehicle body opening and capacitively coupled. In addition, a diversity glass antenna for high frequency is provided which is characterized by utilizing the received signal of the stronger one of the plurality of antenna conductors.

Further, according to the present invention, an electrically heated defogger having a heater wire and a bus bar for supplying power to the heater wire is provided on the glass plate of the rear window of the automobile, and the glass plate of the rear window is provided between the defogger and the defogger. DC current is not transmitted and received, but high frequency current is transmitted and received.Provide at least one antenna conductor of a predetermined pattern that is capacitively coupled in close proximity at a predetermined interval, and between the bus bar and the DC power source for the defogger. A choke coil is inserted in the antenna conductor, and at least one of the plurality of antenna conductors has a loop-shaped main element and sub-element in an electrical sense, and the antenna conductor is close to both the defogger and the vehicle body opening. Capacitively coupling, and further providing at least one antenna conductor which is not capacitively coupled with the defogger on the glass plate of the rear window. Tried out stronger received signals of the part provided or the whole of the antenna conductors to provide a high frequency diversity glass antenna according to claim.

The present invention will be described in detail below with reference to the drawings. FIG. 1 is a block diagram of a representative example of the present invention. In FIG. 1, reference numeral 13 is a connecting line connecting the main element 15 and the sub element 16 of the antenna conductor 14, and 14 is an antenna conductor according to the present invention. Further, in the drawings other than FIG. 1, the parts having the same numbers and the same symbols as in FIG. 1 have the same names.

The antenna conductor 14 has a loop shape in which the main element 15 is DC-closed via a connecting line extending substantially laterally from the feeding point. In addition, the main element 15
The sub-element 16 is further installed, and the sub-element 16 is brought close to the opening of the vehicle body and capacitively coupled. Sub-element 1
When the distance between 6 and the vehicle body opening is about 0.1 to 50 mm, the capacitive coupling is normally performed.

Further, the lateral dimension of the loop shape of the main element 15 is such that the wavelength of the desired receiving frequency is λ, the glass shortening rate is K, the maximum frequency f _{H of} the desired receiving frequency band, and the desired receiving frequency band. When the minimum frequency is f _L , f _L ×
The range of (λ / 4) × K to f _H × (λ / 4) × K is preferable. The glass shortening rate is 0.64.

The loop shape of the main element 15 means a loop in an electrical sense. Therefore, it is not always necessary that the shape of the main element 15 itself is not a perfect loop, and a part of the loop is cut, and when the cut portion is named as an opening, it is necessary that the opening is capacitively coupled. And For medium and high frequency currents,
This opening is short-circuited. The width of the opening is usually 0.1
It is about 50 mm, and capacitive coupling occurs at such a distance.

The length of the loop shape of the main element 15 is not particularly limited, but it is preferable to use most of the blank area below the defogger 3 so that the area of the loop shape becomes relatively large.

The loop shape of the main element 15 may be directly connected to the feeding point, or may be connected to the feeding point via a connecting line.

The sub-element 16 is shown in FIG.
The sub-element 16 shown in FIG.
Although it is in the shape of a letter, the shape is not limited to this, and may be a shape such as a substantially L shape. The sub-element 16 shown in FIG. 1 is connected to the main element 15, but not limited to this,
The sub-element 16 may be connected to the feeding point, or may be connected to a connecting line connecting the main element 15 and the feeding point.

FIG. 2 is a constitutional view of a glass plate 1 for a rear window of an automobile according to the present invention of a type different from that of FIG. In FIG. 2, 23 is a dividing element, 24 is an antenna conductor according to the present invention, 25 is a main element, 26 is a sub-element, and 27 is an opening of the main element 25.

The present invention shown in FIG. 2 is of a type particularly suitable for receiving FM broadcast frequency band. Since the FM broadcasting frequency band is wide band, the main element 25 alone cannot completely cover the entire FM broadcasting frequency band. Therefore, in the structure shown in FIG. 2, the dividing element 23 is connected to the loop of the main element 25 in the vertical direction so as to divide the loop into two.

By doing so, in the desired frequency band,
The low frequency band and the high frequency band can be separately received for each frequency band, and a wide band can be achieved. Further, in FIG. 2, the main element 25 is brought close to the opening of the vehicle body, and the reflected wave from the vehicle body is guided to the main element 25 by utilizing capacitive coupling.

FIG. 3 is a constitutional view of a glass plate 1 for a rear window of an automobile according to a glass antenna device for an automobile of the present invention of a type different from that of FIG. In FIG. 3, 33 is a connecting line,
34 is an antenna conductor according to the present invention, 35 is a main element, 36 is a sub-element, and 37 is an opening of the main element 35.

In the antenna conductor 34 shown in FIG. 3, a connecting wire 33 is attached to the opening 37 of the main element 35, and a sub-element 36 is provided at the tip of the connecting wire 33.

The main element 1 shown in FIGS. 1, 2 and 3
5, 25, 35 and the sub-elements 16, 26, 36 are F
It can be used for both M broadcast and TV broadcast reception.

The present invention is not limited to the high frequency glass antenna shown in FIGS. 1, 2 and 3, but in the present invention, the antenna conductor may be close to both the defogger and the vehicle body opening and capacitively coupled. is necessary. In other words, not only the main element and the sub element, but a part of the antenna conductor according to the present invention needs to be brought close to both the defogger 3 and the body opening (vehicle body ground) and capacitively coupled. By doing so, the receiving sensitivity can be further increased. When the distance between the antenna conductor according to the present invention and the vehicle body opening or the defogger 3 is about 0.1 to 50 mm, normal capacitive coupling is achieved.

The "electrical meaning" of the "loop-shaped main element in the electrical sense" in the present invention means a loop for passing a direct current or an alternating current (medium wave, high frequency, etc.) current. Therefore, the loop may be partially broken.

In the present invention, the choke coil 9 and the high frequency coils 12a and 12b are inserted between the bus bars 5a and 5b and the DC power source 10 for the defogger to increase the impedance of the choke coil 9 and the high frequency coils 12a and 12b in the high frequency band. By doing so, the DC current from the DC power source 10 to the defogger is made to flow, but the current in the high frequency band such as the broadcast frequency band is cut off.

In this way, the choke coil 9 and the high frequency coils 12a, 12b can insulate the heater wire 2 of the defogger and the bus bars 5a, 5b, 5c from the vehicle body ground in a high frequency manner, and the heater wires 2 and the bus bars 5a, 5b, 5c
It is possible to prevent the received current in the high frequency band such as the radio broadcast frequency band, which is induced by, from flowing to the vehicle body ground, and to send this received current to the receiver 20 without leakage.

If only the FM broadcast frequency band is received, only the high frequency coils 12a and 12b are required.
Even when receiving both the medium wave band and the FM broadcast frequency band, the choke coil 9 and the high frequency coils 12a and 12b
If there is a coil that satisfies both functions, only such a coil is required.

Further, according to the present invention, as shown in FIG.
An amplifier may or may not be provided. An impedance matching circuit or a resonance circuit may be provided instead of the FM amplifier.

[0033]

In the present invention, at the wavelength of the desired frequency band,
The optimum receiving sensitivity can be obtained by appropriately adjusting the effective length of the main element.

Further, since the antenna conductor according to the present invention is brought close to the defogger and capacitively coupled, the induced voltage of the received radio wave induced in the defogger can be induced in the antenna conductor according to the present invention, and the antenna according to the present invention. Since the conductor is brought close to the opening of the vehicle body and capacitively coupled, a high frequency reception signal of the FM broadcasting frequency or the television broadcasting frequency from the opening of the vehicle body can be guided to the antenna conductor according to the present invention.

Further, although the detailed operation is unclear, in the present invention, the induced voltage of the radio wave received from the defogger and the high frequency received signal of the FM broadcast frequency or the television broadcast frequency from the opening of the vehicle body are looped. To lead to the element,
It is considered that the induced voltage of the received radio wave is expanded by some action in the main loop element, and as a result, the reception sensitivity is significantly improved.

[0036]

【Example】

Example 1 A high frequency diversity glass antenna similar to that shown in FIG. 1 was produced. The size of the main element 15 in the lateral direction is 80M, which is approximately the center frequency of the FM broadcast frequency band.
It was set to 600 mm in consideration of the glass shortening rate of 0.64 in accordance with the ¼ wavelength of Hz. The lengthwise dimension of the main element 15 was 50 mm. Further, the main element 15 is brought close to the defogger 3 at a distance of 15 mm, and
Capacitively coupled to.

As for the lateral dimension of the sub-element 16, when the dimension was adjusted appropriately, 700 mm contributed most to the improvement of the receiving sensitivity. Further, the sub-element 16 is capacitively coupled to the opening of the vehicle body at a distance of 20 mm. Further, when the connection line 13 connecting the main element 15 and the sub element 16 was appropriately adjusted, the best result was obtained at the position shown in FIG.

As a comparative example, a high frequency glass antenna similar to that shown in FIG. 4 was produced. The antenna conductor 40 has a length of 600
The upper element was brought into close proximity to the defogger 3 at a distance of 5 mm and capacitively coupled to the defogger 3. The distance between the antenna conductor 40 and the vehicle body opening was 60 mm, which was not capacitively coupled.

Compared with the antenna conductor 40 of the comparative example, the antenna conductor 14 of the example 1 had a higher average receiving sensitivity of about 3 dB in the FM broadcast frequency band.

In the first embodiment, as a result of using the stronger one of the received signals of the antenna conductors 6 and 14 by the antenna switching device, FM broadcasting can be received well.

Example 2 A high frequency diversity glass antenna similar to that shown in FIG. 2 was produced. Main element 25
The dimension in the horizontal direction was set to 600 mm in consideration of the glass shortening rate of 0.64 in accordance with the quarter wavelength of 80 MHz which is almost the center frequency of the FM broadcast frequency band. Main element 2
The vertical dimension of 5 was 50 mm, and the dimension of the opening 27 of the main element 25 was 15 mm.

The sub-element 26 is the antenna conductor 2
4 extends substantially laterally from the feeding point 4 and the sub-element 26
The size of the horizontal direction of the
mm contributed most to the improvement of reception sensitivity. Furthermore, the main element 25 was capacitively coupled to the opening of the vehicle body at a distance of 20 mm. Further, the open end of the main element 25 is connected to the antenna conductor 2
It is located near the feeding point of No. 4. Also, sub-element 2
The distance between 6 and the defogger was 5 mm, and the sub-element 26 and the defogger were capacitively coupled. The distance between the dividing element 23 and the left end of the main element 25 is 250 mm.
And

Compared with the antenna conductor 40 of the comparative example, the antenna conductor 24 of the example 2 had a higher average receiving sensitivity of about 3 dB in the FM broadcast frequency band.

In the second embodiment, as a result of using the stronger one of the received signals of the antenna conductors 6 and 24 by the antenna switching device, FM broadcasting can be received well.

Example 3 A high frequency diversity glass antenna similar to that shown in FIG. 3 was produced. Main element 35
The dimension in the horizontal direction was set to 600 mm in consideration of the glass shortening rate of 0.64 in accordance with the quarter wavelength of 80 MHz which is almost the center frequency of the FM broadcast frequency band. Main element 3
The vertical dimension of 5 was 50 mm, and the dimension of the opening 37 of the main element 35 was 15 mm.

When the lateral dimension of the sub-element 36 was appropriately adjusted, 900 mm contributed most to the improvement of the receiving sensitivity. Further, the main element 35 was capacitively coupled to the opening of the vehicle body at a distance of 20 mm. The distance between the sub-element 36 and the defogger was 10 mm, and the sub-element 36 and the defogger 3 were capacitively coupled.

Compared with the antenna conductor 40 of the comparative example, the antenna conductor 34 of the example 3 had a higher average receiving sensitivity of about 3 dB in the FM broadcast frequency band.

In the third embodiment, as a result of using the stronger one of the received signals of the antenna conductors 6 and 34 by the antenna switching device, FM broadcasting can be received well.

[0049]

According to the glass antenna for high frequency of the present invention,
At least one of the antenna conductors has a loop-shaped main element and an auxiliary element in an electrical sense, and since the antenna conductor is close to both the defogger and the vehicle body opening and capacitively coupled, Since the induced voltage of the received radio wave and the high frequency received signal of the FM broadcast frequency or the television broadcast frequency from the opening of the vehicle body are guided to the loop-shaped main element, the induced voltage of the received radio wave is caused by some action in the loop-shaped main element. The reception sensitivity of FM broadcast or television broadcast reception is remarkably improved regardless of whether the FM amplifier is connected to the antenna conductor or not.

Further, in the present invention, since the magnitudes of the received signals of the plurality of antenna conductors are balanced, the frequency of antenna switching operation by the antenna switching device is appropriately performed, and the diversity effect is effectively obtained.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a representative example of the present invention.

FIG. 2 is a structural diagram of a glass plate 1 for a rear window of an automobile according to the present invention, which is different from the type shown in FIG.

FIG. 3 is a structural diagram of a glass plate 1 for a rear window of an automobile according to the present invention of a type different from that of FIG.

FIG. 4 is a block diagram of a conventional automobile glass antenna device.

[Explanation of symbols]

 1: Glass plate of rear window of automobile 1 2: Heater wire 3: Defogger 5a, 5b, 5c: Bus bar 6: Antenna conductor 13: Connection wire 14, 24, 34: Antenna conductor 15, 25, 35: Main element 16 , 26, 36: Sub-element 23: Dividing element 33: Connection wire

Claims (3)

[Claims] 1. An electrically heated defogger having a heater wire and a bus bar for supplying power to the heater wire is provided on a glass plate of a rear window of an automobile, and a direct current is applied between the defogger and the glass plate of the rear window. High-frequency current with a choke coil inserted between the bus bar and the DC power source for the defogger, provided with antenna conductors of a predetermined pattern that are closely coupled at a predetermined interval and capacitively coupled so that high-frequency current is transmitted and received A glass antenna for a high frequency, wherein the antenna conductor has a loop-shaped main element and a sub-element in an electrical sense, and the antenna conductor is close to the opening of the vehicle body and capacitively coupled. . 2. An electrically heated defogger having a heater wire and a bus bar for supplying power to the heater wire is provided on the glass plate of the rear window of the automobile, and a direct current is applied between the defogger and the glass plate of the rear window. To transmit and receive high frequency current, multiple antenna conductors with a certain pattern are placed close to each other at a certain interval and capacitively coupled so that high frequency current is transmitted and received, and a choke coil is inserted between the bus bar and the DC power source for the defogger. , At least one of the plurality of antenna conductors has a loop-shaped main element and sub-element in the electrical sense, and the antenna conductor is brought into close proximity to both the defogger and the vehicle body opening and capacitively coupled to each other, and A high-frequency diversity glass antenna characterized by utilizing the received signal of the stronger one of the antenna conductors. 3. An electrically heated defogger having a heater wire and a bus bar for supplying power to the heater wire is provided on a glass plate of a rear window of an automobile, and a direct current is applied to the defogger on the glass plate of the rear window. At least one antenna conductor with a predetermined pattern that is capacitively coupled at a predetermined interval so that high-frequency current can be transmitted and received, but a choke coil is provided between the bus bar and the DC power source for the defogger so that high-frequency current can be transmitted and received. At least one of the plurality of antenna conductors has a loop-shaped main element and sub-element in an electrical sense, and the antenna conductor is close to both the defogger and the vehicle body opening and capacitively coupled thereto; Further, at least one antenna conductor that is not capacitively coupled to the defogger is provided on the glass plate of the rear window, and is provided on the glass plate of the rear window. Part or high frequency diversity glass antenna characterized by using a stronger received signal among all of the antenna conductor.