JP3393638B2 - Transformer transmission glass antenna - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is provided with an AM antenna pattern and an FM antenna pattern on a window glass of an automobile, and is provided with a transformer for transmitting a received signal from each antenna pattern to a power feeding cable. The present invention relates to a transformer transmission glass antenna for receiving broadcasts.

[0002]

2. Description of the Related Art Conventional window glass antennas for automobiles include
There is an antenna that doubles as an anti-fog heater wire that is formed on the window glass of an automobile, and a choke coil is provided between the DC power supply that supplies the current for heating the heater wire and the bus bar.
It is known to improve the reception sensitivity by increasing the impedance in the AM frequency band of radio.

Further, in the conventional automobile window glass antenna, the dedicated anti-fog heater wire formed on the automobile window glass is not used as an antenna, but a dedicated antenna is formed on the automobile window glass to reduce the cost. There is a choke coilless amplifier type antenna that does not use a choke coil to achieve this.

Further, the applicant of the present invention has been disclosed by JP-A-9-018.
No. 222 in Japanese Unexamined Patent Publication No. 222-
A window glass antenna with a transformer has already been disclosed. This window glass antenna 51 is a dedicated antenna 53
, A dual-purpose antenna composed of an anti-fog heater wire 55 connected to a bus bar 54 composed of 54a and 54b, and an impedance conversion transformer 57.
Is connected to one end 57a of the primary winding of the impedance conversion transformer 57, is connected from a position 57b in the middle of the primary winding to the dual-purpose antenna via the lead wire 55a, and the secondary winding is connected to the power supply cable 56. This is a window glass antenna with a choke coilless transformer that can obtain the receiving sensitivity without any problems in actual use even if the choke coil is removed because the impedance is converted by connecting to the.

[0005]

However, in the conventional window glass antenna for automobiles, the choke coil provided for preventing the deterioration of the reception sensitivity is tens of amperes for heating the anti-fog heater wire. In addition to requiring a capacity to withstand the above current, and a large inductance for sufficiently increasing the AC impedance in the AM frequency band, the size is large and it is difficult to secure a mounting space. There is a problem that the material cost and the like including the outer case in which the product is built in rises and the product cost increases.

In addition, in the conventional type with a choke coilless amplifier as an automobile window glass antenna, since a choke coil is not used, it is necessary to create a pattern in a place other than the hot wire portion, and therefore the size of the pattern is large. However, there is a problem in that an expensive amplifier must be used to compensate for the decrease in AM sensitivity.

The window glass antenna 51 disclosed in Japanese Unexamined Patent Publication No. 9-018222 includes a dedicated antenna 53.
However, since there is only a pillar as a ground close to the terminal position of the dual-purpose antenna, and therefore it does not function as a sufficient ground, there is a problem that sufficient reception sensitivity cannot be obtained in the FM band.

The present invention has been made to solve the above-mentioned problems of the prior art, and its object is to provide an inverted T-shaped first FM antenna pattern and an anti-fog heater wire. Second FM laid in the window pane area being
First and second AMs laid on the left and right of the upper part of the window glass where the antenna pattern and the anti-fog heater wire are not arranged
It is an object of the present invention to provide a transformer transmission glass antenna that includes an antenna pattern and a transformer for impedance conversion, does not require a choke coil and an amplifier, and can secure good AM / FM reception sensitivity.

[0009]

In order to solve the above-mentioned problems, a transformer transmission glass antenna according to the present invention is an FM power feeding electrode laid in the central portion near the upper edge of a window glass, and a window from the FM power feeding electrode. A vertical conductor pattern that extends substantially vertically to the upper edge of the glass and extends downward to the topmost line of the anti-fog heater wire, and a horizontal conductor that is attached near the topmost line of the anti-fog heater wire. An inverted T-shaped first FM antenna pattern including a conductor pattern and a second FM antenna pattern laid on an extension of the vertical conductor pattern in the window glass region where the anti-fog heater wire is disposed. Installed near the center of the upper edge of the window glass
The AM power supply electrode and the anti-fog heater wire are installed.
Inverted T-shaped first FM antenna on top of no window glass
The first AM antenna pattern laid on the left side of the pattern
And the top of the window glass without the anti-fog heater wire
On the right side of the first inverted T-shaped FM antenna pattern
And a second AM antenna pattern provided,
The M antenna pattern and the second AM antenna pattern
It is characterized in that it is connected to an AM power supply electrode.

The transformer transmission glass antenna according to the present invention has an FM laid in the central portion near the upper edge of the window glass.
A power supply electrode, a vertical conductor pattern extending from the FM power supply electrode substantially perpendicularly to the upper edge of the window glass and in a downward direction to a position adjacent to the uppermost step line of the anti-fog heater wire, and an anti-fog heater wire An inverted T-shaped first FM antenna pattern consisting of a horizontal conductor pattern provided adjacent to the uppermost line of
Since the second FM antenna pattern laid on the extension of the vertical conductor pattern is provided in the window glass region where the anti-fog heater wire is arranged, a good FM can be obtained without using a choke coil and an amplifier. It is possible to secure reception sensitivity.

The trans-transmission glass antenna according to the present invention is an AM installed near the center of the upper edge of the window glass.
A first AM antenna pattern laid on the left side of the inverted T-shaped first FM antenna pattern on the upper part of the window glass on which the power feeding electrode and the anti-fogging heater wire are not arranged, and the anti-fogging heater Inverted T on top of the window glass where no line is placed
Since the second AM antenna pattern laid on the right side of the character-shaped first FM antenna pattern is provided, the FM feeding electrode can be attached to the central portion near the upper edge of the window glass.

In the transformer transmission glass antenna according to the present invention, since the first AM antenna pattern and the second AM antenna pattern are connected to the AM feeding electrode, the area of the AM antenna pattern can be increased and the choke. Good AM reception sensitivity can be secured without using a coil and an amplifier.

Furthermore, trans-transmission glass antenna according to the present invention is characterized in that there was 1 Tsunishi share the FM feeding electrode and the AM feeding electrode.

In the transformer transmission glass antenna according to the present invention, the FM power feeding electrode and the AM power feeding electrode are commonly used.
As a result, the number of terminals on the primary winding side of the transformer for impedance conversion can be set to one, and one connector for connecting the impedance conversion transformer and the FM / AM power supply electrode can be used in common. Since the area of the AM antenna pattern can be increased,
AM reception sensitivity can be improved.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a configuration diagram of a transformer transmission glass antenna according to the present invention. In FIG. 1, the transformer transmission glass antenna 1 includes a window glass 10, an FM power feeding electrode 11, a first FM antenna pattern 12a, a second FM antenna pattern 12b, and an AM power feeding electrode 1.
3, the first AM antenna pattern 14a, the second AM antenna pattern 14b, the anti-fog heater wire 18 and the transformer 15 connected to the bus bar (19a, 19b).

[0016] FM power supply electrode 11, AM power supply electrode 1
3, FM antenna pattern (12a, 12b) and A
The M antenna pattern (14a, 14b) is formed by, for example, screen-printing a conductive paste obtained by forming fine particles of silver, low-melting glass powder, etc. with an organic solvent on the window glass 10 and firing the conductive paste. It is formed using a conductive member such as a wire, a conductive metal thin wire, or a conductive metal foil.

The anti-fogging heater wire 18 is a heater wire formed by, for example, printing a thin nichrome wire or a silver conductive paste on the window glass 10 by screen printing and then firing it. The power source for heating the heater wire is As shown in FIG. 9, a capacitor C50 for absorbing noise is connected between both electrodes, for example, from a DC power source PS of an automobile battery to a bus bar (19
a, 19b).

FIG . 2 is a block diagram of the transformer of the transformer transmission glass antenna according to the present invention. In FIG. 2, the transformer 15 is a transformer for impedance conversion,
Primary winding 20, secondary winding 21, capacitor C1, primary side terminals (15a, 15a) and secondary side terminal (15
c, 15d).

The AM power supply electrode 13 has a connection line 16a
It is connected to the terminal 15 a on the secondary side and is connected to the primary winding 20. The FM power supply electrode 11 is connected to the terminal 15b on the primary side by the connection line 16b, and is connected to the intermediate tap of the primary winding 20 via the capacitor C1.

The secondary side terminal 15c is connected to the core wire 17c of the power feeding cable 17 formed of, for example, a coaxial cable, and
The terminal 15d on the next side is the outer conductor 17d of the power supply cable 17.
To the outer conductor 17d through the coaxial connector 15e.
Connects to the car body.

[0021] The primary winding 20 and the number of turns of the secondary winding 21,
AM antenna patterns (14a, 14b) mainly connected to the primary side terminal 15a, and secondary side terminals 15c, 15d
It is set according to the impedance of the power supply cable 17 connected in between and the conditions such as the frequency band of the received signal.

[0022] For example, the impedance is 50Ω in the feeder cable 17, capacitance at 120 pF, when receiving the radio broadcast AM / FM may, AM antenna pattern (14
a, 14b) side and the power supply cable 17 side impedance are matched so that optimum sensitivity is obtained.
The winding ratio of the primary side and the secondary side of No. 5 is set.

It is desirable that the winding ratio of the primary side and the secondary side of the transformer 15 is set to 9: 1 from the result of the cut-and-try experiment so that practically no problem of receiving sensitivity can be obtained. An intermediate tap for connecting the capacitor C1 is provided in the middle of the winding 20 of FIG.

[0024] The AM antenna patterns (14a, 14b)
The gain is increased as the antenna capacity is larger than the capacity of the power supply cable 17, and the reception sensitivity is improved.

[0025] The AM antenna patterns (14a, 14b)
The received signal from the transformer 1 for impedance conversion
5 is transmitted to the terminal 15a and the reception sensitivity is improved by the AM antenna pattern (14a, 14b) and the feeding cable 17
When the transformer 15 for impedance conversion is provided, the capacity of the power feeding cable 17 seen from the AM antenna patterns (14a, 14b) can be reduced, and the transmission loss can be reduced. It can be reduced.

[0026] Alternatively, in the case in which a transformer 15 for impedance conversion, viewed from the feeder cable 17 A
It can be said that the capacity of the M antenna pattern (14a, 14b) has increased.

On the other hand, the received signal from the FM antenna pattern (12a, 12b) which acts as an FM antenna,
It is transmitted to the terminal 15b of the transformer 15 for impedance conversion that performs impedance conversion between the FM antenna pattern (12a, 12b) and the power supply cable 17.

When the FM antenna pattern 12 is directly coupled to the anti-fog heater wire 18, the input impedance of the FM antenna pattern 12 increases due to the influence of the anti-fog heater wire 18, and the impedance with the power supply cable 17 increases. Inconsistency occurs, and the signal sensitivity decreases.

In order to avoid direct coupling of the FM antenna pattern 12 with the anti-fogging heater wire 18, the FM antenna pattern 12 of the transformer transmission glass antenna 1 has a vertical conductor pattern and an anti-fogging heater as shown in FIG. The inverted T-shaped first FM antenna pattern 12a consisting of a horizontal conductor pattern provided adjacent to the uppermost line of the wire 18 and the window glass region where the anti-fog heater wire 18 is provided are laid. The second FM antenna pattern 12b is divided into two parts, and by the horizontal conductor pattern of the first FM antenna pattern 12a, the first FM antenna pattern 12a, the second FM antenna pattern 12b, and the anti-fogging heater wire 18 are provided.
Is configured to be capacitively coupled to the uppermost line of the.

Further , the first FM antenna pattern 12a
By selecting the line shortening rate that is determined by the size of the coupling capacitance between the horizontal conductor pattern provided adjacent to the uppermost line of the antifogging heater wire 18 and the uppermost line of the antifogging heater wire 18, The input impedance of the fog heater wire 18 can be made very high, the anti-fog heater wire 18 can be separated from the second FM antenna pattern 12b, and the reception sensitivity of the FM antenna pattern 12 can be increased. Can be improved.

[0031] The AM antenna patterns (14a, 14b)
And the received signal from the FM antenna pattern 12 is A
The combined reception signal of the M / FM band is transmitted from the impedance conversion transformer 15 through the power supply cable 17 through the coaxial connector 15e to the external receiver (not shown).

The AM antenna pattern (14a, 1
In order to improve the receiving sensitivity of 4b), it is effective to lower the antenna impedance, and in order to lower the antenna impedance, the AM antenna pattern (1
It is preferable to form the conductor patterns 4a and 14b) as large and long as possible to increase the antenna capacitance. Instead of the linear conductor pattern, for example, a transparent planar conductor pattern may be formed.

[0033] Thus, the transformer transmitting glass antenna 1 according to the present invention, instead of the choke coil, comprising a transformer 15 for impedance conversion, AM antenna patterns (14a, 14b) and the FM antenna pattern 12 and the feeding cable 17 It is possible to ensure good reception sensitivity by performing impedance conversion between them.

FIG . 3 is a configuration diagram for measuring the receiving sensitivity of the transformer transmission glass antenna according to the present invention. here,
The same parts as those of the transformer transmission glass antenna 1 shown in FIG. 1 are designated by the same reference numerals and the description thereof will be omitted. In FIG. 3, each dimension for measuring the reception sensitivity of the transformer transmission glass antenna 2 is set as follows. d1: 900mm, d2: 780mm, d3: 50mm, d4: 140mm, d5: 140mm, d6: 1100mm d7: 450mm, d8: 120mm, d9: 30mm

FIG . 4 is a test system configuration diagram for measuring the reception sensitivity of the transformer transmission glass antenna 2 according to the present invention. In FIG. 4, the transformer 15 has a winding ratio of 9: 1, and the secondary side terminals (15c, 15d) of the transformer 15 are connected with a coaxial cable (feeding cable 17) 4m having a capacity of 30 pF per meter, and the outside. The conductor 17d connects to the body of the vehicle.

[0036] 4m of coaxial cable (power supply cable 17)
The other end of the core wire 17e is connected to the intermediate tap 22a of the transformer 22 having a winding ratio of 1, and the reception signal in the AM frequency band is output from the terminal 22c of the winding ratio 9 to a measuring device (not shown).
The reception signal in the FM frequency band is output to a measuring device (not shown) through the capacitor C2. The outer conductor 17g at the other end of the 4 m coaxial cable (feed cable 17) is connected to the terminal 22b of the transformer 22 and the ground terminal of a measuring device (not shown).

[0037] The graph of AM reception sensitivity characteristic of the transformer transmission glass antenna 2 as measured on the basis of the above measurement conditions in FIG. 5 shows a graph of FM reception sensitivity characteristic in FIG.

The AM reception sensitivity characteristic of FIG .
5, 22) was used, the AM reception sensitivity of the pole antenna was set to 0 dB, and the AM reception sensitivity characteristic (TRS) of the transformer transmission glass antenna 2 measured by the test system shown in FIG. 6 is a graph showing the AM reception sensitivity characteristic (30 pF × 4 m) of the transformer transmission glass antenna 2 measured without using it.

From the AM reception sensitivity characteristic of FIG . 5, the transformer transmission glass antenna 2 has a maximum value of about (-) in the AM frequency band as compared with the AM reception sensitivity characteristic of the pole antenna.
Although it shows a decrease of 2.5 dB), a reception sensitivity level that does not pose a problem in actual use is secured.

The FM reception sensitivity characteristic of FIG . 6 is 60 dBμV.
5 is a graph showing FM reception sensitivity characteristics of the transformer transmission glass antenna 2 measured by the test system shown in FIG. 4 under an electric field strength of / m.

From the FM reception sensitivity characteristics of FIG . 6, the transformer transmission glass antenna 2 has a frequency of 76 MHz to a frequency of 90 MHz.
40 dB μV to 45 dB in the FM frequency band of MHz
Since the μV reception sensitivity level is secured, there is no problem in actual use.

FIG . 7 is a block diagram of a transformer transmission glass antenna according to the present invention. Here, the same parts as those of the transformer transmission glass antenna 1 shown in FIG. 1 are designated by the same reference numerals and the description thereof will be omitted. In FIG. 7, the transformer transmission glass antenna 3 includes a window glass 10, an AM / FM feeding electrode 26, an FM antenna pattern 12, a first AM antenna pattern 14a, and a second AM antenna pattern 14.
b, an anti-fog heater wire 18 and a transformer 25 connected to the bus bar (19a, 19b).

The AM / FM power feeding electrode 26 is formed by connecting the FM power feeding electrode 11 and the AM power feeding electrode 13 shown in FIG. 1 in common.

FIG . 8 is a block diagram of the transformer of the transformer transmission glass antenna 3 according to the present invention. Figure 8
In FIG. 1, the transformer 25 is a transformer for impedance conversion, and includes a primary winding 30, a secondary winding 31, a capacitor C3, a primary side terminal 25a and a secondary side terminal (25
c, 25d).

The AM / FM feeding electrode 26 of the transformer transmission glass antenna 3 shown in FIG . 7 is connected to the primary side terminal 25a by the connection line 16 and is connected to the primary winding 30.

[0046] the secondary signal received AM frequency band primary winding 30 and the electromagnetic induction of the secondary winding 31 terminal 25c
The received signal in the FM frequency band is transmitted to the capacitor C3.
Through the secondary side terminal 25c.

[0047] Thus, the transformer transmitting glass antenna 3 according to the present invention, since one was Tsunishi share the FM feeding electrode and the AM feeding electrode, the transformer primary winding terminals for impedance conversion Can be one, and good AM / FM reception sensitivity can be secured.

The above embodiment is an example of the present invention, and the present invention is not limited to the above embodiment.

[0049]

The present invention has the following effects due to the above configuration. The transformer transmission glass antenna according to the present invention is provided with an FM power feeding electrode laid in the central portion near the upper edge of the window glass, and for anti-fogging from the FM power feeding electrode substantially vertically to the upper edge of the window glass and downward. An inverted T-shaped first FM antenna pattern consisting of a vertical conductor pattern extending to a position closest to the uppermost line of the heater wire and a horizontal conductor pattern provided adjacent to the uppermost line of the antifogging heater wire. And the second FM antenna pattern laid on the extension of the vertical conductor pattern in the window glass region where the anti-fog heater wire is arranged, it is preferable without using a choke coil and an amplifier. Since it is possible to secure a sufficient FM reception sensitivity, stable AM / FM radio broadcasting can be received, and cost reduction can be expected.

In the transformer transmission glass antenna according to the present invention, the AM power feeding electrode laid near the center of the upper edge of the window glass and the upper portion of the window glass on which the anti-fog heater wire is not provided, The first AM antenna pattern laid on the left side of the inverted T-shaped first FM antenna pattern and the inverted T-shaped first FM on the upper portion of the window glass on which the anti-fog heater wire is not provided. Since the second AM antenna pattern laid on the right side of the antenna pattern is provided, the FM
Since the power supply electrode can be attached to the central part near the upper edge of the window glass, power can be supplied at the upper position of the window glass,
The visibility in the rear can be improved, and the commercialability can be improved.

[0051] Further, the transformer transmitting glass antenna according to the present invention, the first AM antenna pattern and the second AM
Since I connected the antenna pattern to the AM feeding electrode,
The area of the AM antenna pattern can be increased,
Since it is possible to secure good AM reception sensitivity without using a choke coil and amplifier, stable A
It is possible to receive M radio broadcasting, and it is expected that the price will be reduced.

Further, in the transformer transmission glass antenna according to the present invention, the FM power feeding electrode and the AM power feeding electrode are shared to be one, and the terminal on the primary winding side of the impedance conversion transformer is made to be one. Therefore, the size of the transformer can be reduced and the economy can be expected.

[0053] Further, the transformer transmitting glass antenna according to the present invention, 1 Tsunishi share of the FM feeding electrode and the AM feeding electrode, connector wiring of the FM / AM feeding electrode and the transformer for impedance conversion Common 1
Since it is possible to reduce the number of parts and the number of assembling steps, it is possible to improve workability and improve economy.

Further, in the transformer transmission glass antenna according to the present invention, the FM power feeding electrode and the AM power feeding electrode are shared to be one, and the area of the AM antenna pattern can be increased, so that the AM receiving sensitivity is improved. Can be improved.

[0055] Accordingly, the present invention has good workability, high performance, it is possible to provide a transformer transmission glass antenna which is economical AM / FM receiving antenna for an automobile.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a transformer transmission glass antenna according to the present invention.

FIG. 2 is a configuration diagram of a transformer of a transformer transmission glass antenna according to the present invention.

FIG. 3 is a configuration diagram for measuring the reception sensitivity of a transformer transmission glass antenna according to the present invention.

FIG. 4 is a configuration diagram of a test system for measuring the reception sensitivity of the transformer transmission glass antenna 2 according to the present invention.

FIG. 5 is an AM reception sensitivity characteristic graph of the transformer transmission glass antenna 2 according to the present invention.

FIG. 6 is an FM reception sensitivity characteristic graph of the transformer transmission glass antenna 2 according to the present invention.

FIG. 7 is a configuration diagram of a transformer transmission glass antenna according to the present invention.

FIG. 8 is a configuration diagram of a transformer of the transformer transmission glass antenna 3 according to the present invention.

FIG. 9 is a configuration diagram of a conventional window glass antenna for an automobile.

[Explanation of symbols]

1 ... Transformer transmission glass antenna, 10 ... Window glass, 1
1 ... FM feeding electrode, 12 ... FM antenna pattern, 1
2a ... 1st FM antenna pattern, 12b ... 2nd F
M antenna pattern, 13 ... AM power feeding electrode, 14a ...
1st AM antenna pattern, 14b ... 2nd AM antenna pattern, 15, 22, 25, 57 ... Transformer, 1
5a, 15b, 57a, 57b ... Primary side terminal, 15
c, 15d ... Secondary side terminal, 15e ... Coaxial connector, 1
6a, 16b ... Connection line, 17, 56 ... Power supply cable, 1
7d, 17g ... Outer conductor, 17e ... Core wire, 18, 55 ...
Anti-fog heater wire, 19a, 19b, 54, 54a, 54
b ... bus bar, 20, 30 ... primary winding, 21, 31 ... 2
Next winding, 22a, 22b ... Intermediate tap, 22c, 25
a, 25c, 25d ... Terminal, 51 ... Window glass antenna,
53 ... Dedicated antenna, d1, C1, C2, C3, C50 ... Capacitor, d2, d3, d4, d5, d6, d7, d8, d9: ...
Dimensions, PS ... DC power source for automobile batteries.

Continuation of front page (56) Reference JP-A-8-139510 (JP, A) JP-A-9-18222 (JP, A) JP-A-8-222930 (JP, A) JP-A-3-201702 (JP , A) (58) Fields investigated (Int.Cl. ⁷ , DB name) H01Q 1/32

Claims (2)

(57) [Claims] 1. A window glass antenna in which an AM antenna pattern and an FM antenna pattern are provided on a window glass of an automobile provided with an anti-fog heater wire, and a feed cable by impedance-converting a received signal from the window glass antenna. A transformer transmission glass antenna having a transformer for transmitting to an FM, the FM being laid in a central portion near an upper edge of the window glass.
A power feeding electrode; a vertical conductor pattern extending from the FM power feeding electrode substantially vertically to the upper edge of the window glass and downward to a position close to the uppermost step line of the anti-fog heater wire; The inverted T-shaped first FM antenna pattern including a horizontal conductor pattern provided adjacent to the uppermost line of the fog heater wire, and the window glass region in which the anti-fog heater wire is provided. in the second of the FM antenna pattern laid on the extension of the vertical conductor pattern, Bei example were laid in the vicinity of the central portion of the upper edge of the window glass AM
A power supply electrode and the window glass not provided with the anti-fog heater wire
On the upper side, the inverted T-shaped first FM antenna pattern
The first AM antenna pattern laid on the left side and the window glass on which the anti-fog heater wire is not provided
On the upper side, the inverted T-shaped first FM antenna pattern
A second AM antenna pattern laid on the right side, and the first AM antenna pattern and the second AM antenna pattern.
Connect the AM antenna pattern to the AM feeding electrode
This is a glass antenna for transformer transmission. 2. A method according to claim 1 Symbol <br/> mounting of the transformer transmission glass antenna wherein said was an FM feeding electrode and the AM Tsunishi 1 share the feeding electrode.