JP4941171B2 - Glass antenna for vehicles - Google Patents

Description

  The present invention is a vehicle in which a non-grounding type terrestrial digital TV broadcast wave receiving antenna is provided at a corner portion of a window glass on the side of a rear seat for an automobile so that high sensitivity and stable reception performance can be obtained. The present invention relates to a glass antenna.

  Conventionally, in the case where a coaxial cable is provided between an AM / FM radio broadcast wave receiving antenna provided on a window glass of an automobile or a TV broadcast wave receiving antenna and a receiver, Separate the conductor in the middle of the metal body of the car body, connect the external conductor to the metal body near the separation position, and extend only the internal conductor from the vicinity of the connection position of the metal body with the lead wire, and connect it to the feeding point of the glass antenna I was letting.

  However, when the frequency is in the AM / FM radio broadcast wave band such as 522 to 1629 KHz or 76 to 90 MHz, the length of the lead wire from the connection position of the negative electrode to the feeding point of the glass antenna is the reception frequency. The length of the lead wire does not significantly affect the reception performance of the antenna because it is significantly shorter than the wavelength of the wavelength, but if the frequency becomes higher, such as the UHF broadcast wave band of 470 to 770 MHz, it will be negative. The length of the lead wire from the connection point on the side to the feeding point of the glass antenna becomes longer than the wavelength of the reception frequency, and the length of the lead wire affects the reception performance of the antenna, and the reception performance varies. Therefore, as a countermeasure against this, in coaxial cable wiring, the outer and inner conductors of the coaxial cable are separated near the glass antenna. Thereby, to connect the respective feed point of the separate antenna wire by a non-ground type antenna with one system together these, high stability, it has been carried out to realize a high sensitivity.

  Furthermore, television broadcast waves are now shifting from terrestrial analog broadcasts in the VHF band and 470-770 MHz UHF band to 470-710 MHz terrestrial digital broadcasts. It is becoming necessary to support digital broadcasting, and transmission / reception of terrestrial digital broadcasting requires a highly sensitive antenna, especially compared to transmission / reception of terrestrial analog broadcasting, and an ungrounded antenna must be adopted as an antenna system. However, it is necessary to reduce the area of the non-grounded antenna, which has a larger area than the grounded antenna.

  As the non-grounded antenna, for example, in Japanese Patent Application Laid-Open No. 7-46016, a hot-side antenna wire is attached to a window glass in a horizontal direction and a metal window frame of a vehicle body to which the window glass is attached. It is disposed so as to be electromagnetically coupled to the upper or lower horizontal side, and the ground side antenna wire is arranged inward of the window glass from the hot side antenna wire, and one end thereof is connected to the hot side antenna wire. There is described a window glass antenna for a car phone characterized in that it is disposed close to one end or the center of the antenna (Patent Document 1).

  Also, for example, in Japanese Patent Application Laid-Open No. 2006-165933, two systems of non-grounded antennas having conductive wires extending from the feeding points of the positive electrode and the negative electrode are arranged on the same glass surface. In a glass antenna for a vehicle that receives diversity, a feeding point for one negative electrode is provided on the glass plate surface, two feeding points for positive electrodes are provided in the vicinity of both sides, and the outer conductor antenna is extended from the feeding point for the negative electrode. A central conductor antenna is arranged from each of the feeding points, and the internal conductors of the two coaxial cables are connected to the two positive feeding points, respectively, and the two external conducting wires are connected to the negative feeding point. The glass antenna for vehicles is described (patent document 2).

Further, for example, Japanese Patent Application Laid-Open No. 2006-197184 discloses a vehicle glass antenna provided on a rear window glass plate provided with an electrically heated defogger for a rear window of the vehicle, and the defogger includes the rear window glass plate. Bus bars provided in the vertical direction on both left and right end sides, and a plurality of heater wires provided in the horizontal direction from the lower side to the upper side of the rear window glass plate to connect the bus bars, and the rear window The glass plate has a high-frequency antenna conductor above the defogger on at least one of the left and right end portions, and the uppermost heater wire and the high-frequency antenna conductor of the heater wires are connected to the rear window. The uppermost heater wire is separated by 50 mm or more in the vertical direction of the glass plate. There is described a glass antenna for a vehicle characterized by having a branch heater wire that extends in the horizontal direction after branching upward from a steel plate (Patent Document 3).
JP 7-46016 A JP 2006-165933 A JP 2006-197184 A

  As described above, the non-grounded antenna as shown in Patent Document 1 has a total number of coaxial cable terminals in order to connect both the external conductor and the internal conductor of the coaxial cable to separate antennas. Not only increases and becomes complicated, but if a plurality of antennas are arranged in a limited space, the antennas are placed close to each other and adversely affect each other. There is a problem that the antenna cannot be obtained, and it is necessary to dispose the antennas at positions distant from each other. In this case, there is a problem that the coaxial cable must be installed at various points on the glass plate.

  Further, the non-grounded antenna as disclosed in Patent Document 2 has a problem in that it is difficult to obtain a stable reception gain due to large variations in reception gain.

  Furthermore, the non-grounded antenna as disclosed in Patent Document 3 is susceptible to radiation noise from the defogger, and there is a problem that the antenna performance may be deteriorated.

  The present invention has been made to solve such problems. An antenna for an ungrounded digital television is provided in a narrow space of a window glass plate for an automobile, and the occupied area of the antenna is reduced. The purpose is to reduce the variation in reception gain without deteriorating the antenna performance, and to obtain a high-sensitivity and stable reception gain, while reducing the area and reducing radiation noise from the defogger. .

That is, the present invention relates to an antenna for receiving terrestrial digital TV broadcast waves provided in a corner portion of a window glass on the side of a rear seat of an automobile, and a positive electrode and a negative electrode provided in the vicinity of the corner portion of the side window glass. It consists of two feeding points , a first element connected to the positive feeding point, and a second element connected to the negative feeding point, the first element being the positive feeding point Two filaments connected to each other, and at least one of the two filaments is a first vertical filament extending perpendicularly toward a corner direction, and the first filament A first horizontal wire connected to the tip of the vertical wire, and the second element is connected to the feeding point of the negative electrode and has at least two second wires extending in the horizontal direction. Connected to horizontal wire and feeding point of the negative electrode Is has become and a second vertical strip which extends in the vertical direction, the positive electrode, each feeding point of the negative electrode that it has a non-grounded type antenna connected core, and the outer skin conductor of coaxial cable, respectively It is the glass antenna for vehicles characterized.

Alternatively, according to the present invention, of the two filaments constituting the first element , one filament is a line composed of the first vertical filament and the first horizontal filament. a strip, the striatum of another one is connected to a feeding point of the positive electrode, which is above the glass antenna for a vehicle which is a third horizontal strip which is extended in the horizontal direction.

  Alternatively, in the present invention, the third vertical filament is extended from the tip of the third horizontal filament in the vertical direction, and the third vertical filament is folded back from the tip of the third vertical filament to the vicinity of the feeding point of the positive electrode. It is the above-mentioned glass antenna for vehicles characterized by providing a return line.

  Alternatively, in the present invention, as the first element, the two first vertical filaments extending in the vertical direction from the feeding point of the positive electrode, and further, do not intersect each other horizontally and in the same direction from the respective leading ends or midway. The above-described glass antenna for a vehicle is provided with a first horizontal filament extended in this manner.

  Alternatively, in the present invention, any one of the above-described features is characterized in that the auxiliary vertical filament is arranged in a direction away from the other second horizontal filament from the tip of one second horizontal filament of the second element. A glass antenna for a vehicle according to claim 1.

  Alternatively, according to the present invention, the length of the first element is set to 1 / 4αλ to 3 / 4αλ (α: wavelength shortening rate, λ: wavelength of received radio wave). This is a glass antenna for vehicles.

  Alternatively, the present invention is characterized in that the antenna comprising the first element and the second element is arranged at the corners of the window glass on the rear side of the left and right sides of the vehicle, respectively, to receive diversity. The vehicle glass antenna according to any one of the above.

  According to the present invention, it is possible to reduce the area occupied by the antenna and the variation in the reception gain of the antenna, which have been problems in the past, and to perform digital terrestrial TV broadcast waves even in a narrow space with limited window glass plates for automobiles. A non-grounded antenna can be installed, and high-sensitivity and stable reception performance can be obtained.

  The present invention is a glass antenna provided on the interior surface of a fitted window glass on the rear seat side of a side window glass of an automobile, and a frequency in which a conductive ceramic paste is provided by printing near a corner portion of the glass plate surface Is a glass antenna capable of receiving terrestrial digital television broadcast waves of 470 to 710 MHz with high performance (see FIG. 4).

  As shown in FIG. 1 and FIG. 2, the glass antenna is provided with two feeding points 3 and 4, a positive electrode and a negative electrode, in the vicinity of the corner portion of the glass plate 1. The first element 10 is extended and the second element 20 is extended from the negative feeding point 4. The positive feeding point 3 and the negative feeding point 4 are respectively connected to the center of the coaxial cable 2. This is a non-grounded antenna in which the conductor 2a and the outer conductor 2b are connected.

As shown in FIG. 1, as the first embodiment of the present invention, the first element 10 is composed of at least two filaments extending from the positive feed point 3, and the two filaments. At least one of the strips is connected to the first vertical strip 11 extending perpendicularly toward the corner direction from the feed point 3 of the positive electrode, and connected to the tip of the first vertical strip 11 in the horizontal direction. It consists of the extended first horizontal filament 12.

  Further, the first element 10 includes a third horizontal line 13 extending further in the horizontal direction from the positive feed point 3 in addition to the strips 11 and 12 extending from the positive feed point 3. You may make it provide.

  Further, the third vertical wire 14 is extended from the tip of the third horizontal wire 13 in the vertical direction, and the folded back from the tip of the third vertical wire 14 to the vicinity of the feeding point 3 of the positive electrode. The filament 15 may be provided.

  On the other hand, the second element 20 includes at least two second horizontal wires 22 and 22 extending in a horizontal direction from the negative feed point 4 and a vertical distance from the negative feed point 4 to the positive feed point 3. It consists of a second vertical filament 21 extending in the direction.

Next, as shown in FIG. 2, in the second embodiment of the present invention, the first element 10 has two first vertical wires 11, 11 in the vertical direction from the feeding point 3 of the positive electrode. The first horizontal filaments 12 and 12 ′ that are extended from each tip so as not to cross each other in the same direction in the horizontal direction are arranged.

  Further, an auxiliary vertical filament 25 is disposed in a direction away from the other second horizontal filament 22 from the tip of one second horizontal filament 22 of the second element 20. As a result, the impedance can be adjusted, the VSWR characteristics can be further improved, and the reception gain can be improved.

  It is preferable that the length of the first element is ¼αλ to 3 / 4αλ (α: wavelength shortening rate, λ: wavelength of received radio wave) because the frequency characteristics become flat. Is preferred.

  In addition, the glass antenna of the invention is provided at the corner portion of a small area window glass called a fitting window or rear quarter on the rear seat side of the side part of the automobile, but the front window glass and the rear window glass You may make it provide in any corner part. In addition, it is preferable to arrange them at the corners of the window glass on the rear side of the left and right sides of the automobile and receive diversity by using a plurality of antennas because the directivity is improved.

  The first horizontal filament 12 and the first vertical filament 11 of the antenna of the present invention are preferably provided at least 5 to 15 mm away from the inside of the flange frame 30 of each window. This is because when the antenna of the present invention is close to the body, the received radio wave is prevented from leaking by the body and the reception gain is reduced.

  FIGS. 1 and 2 show glass capable of receiving high-performance terrestrial digital television broadcast waves having a frequency of 470 to 710 MHz provided in the vicinity of a corner portion on the interior surface of a window glass on the side of a rear seat of an automobile. It is an antenna.

  When the feeding point is provided at the four corners of the window glass on the side of the rear seat of the automobile, the wiring of the coaxial cable 2 can be easily operated, the appearance, or the driver's window glass can be used. It is also desirable for visibility outside the vehicle.

  Moreover, when providing the antenna of this invention in the front window glass of a motor vehicle, although not shown in figure, it is good to provide in both corner parts of the upper part side of a front window glass so that a driver | operator's visual field may not be disturbed.

  Even when the antenna of the present invention is provided on the rear window glass of an automobile, it is preferably provided at the four corners which are not shown but do not adversely affect the defogger.

  In addition, the antenna of the present invention may be provided at a plurality of locations for diversity reception.

The operation of the present invention will be described below.
The first element 10 and the second element 20 that are the antennas of the present invention are separated from the inside of the opening of the flange frame 30 of the rear window side of the rear side of the automobile by 5 to 15 mm. In order not to be affected by the metal body, it is better to keep it away from the window flange frame 30. New problems such as conspicuousness and interference with other antennas occur, and the rear window glass also has problems such as interference with a defogger and other antennas.

  Further, by providing the first horizontal line 12 in the first element 10, the frequency characteristic becomes flat, and the first vertical line 11 of the first element 10 or the positive feed point directly in the vertical direction. An extended second vertical line 13 is provided, and a third vertical line 14 is connected from the tip of the third horizontal line 13, and a folded line is formed from the tip of the third vertical line 14. By connecting 15, the receiving sensitivity of the antenna can be greatly improved.

Examples of the present invention and comparative examples will be described below.
[Example 1] As shown in FIG. 1, the upper corner of the vertical side of the window glass plate 1 is provided in the upper corner portion of the fitting window on the rear seat side of the side portion called the rear quarter of the automobile. Two feeding points 3 and 4 are arranged close to each other in the order of the positive electrode and the negative electrode from the upper side in the vicinity of the part, and the first element 10 is provided at the positive electrode as the feeding point and the second element 20 is provided at the negative electrode feeding point. Connected.

  The first element 10 extends a first vertical wire 11 having a wire length of 15 mm from the positive electrode feeding point 3 to the vicinity of the upper corner, and extends along the upper edge of the opening of the window flange frame 30 from its tip. The first horizontal filament 12 having a filament length of 160 mm was connected and extended in a substantially horizontal direction. Further, a third horizontal line 13 having a line length of 130 mm is extended in the horizontal direction from the feeding point 3 of the positive electrode, and a third vertical line 14 having a line length of 5 mm is extended above the tip, Further, a folded line 15 having a length of 130 mm was provided in the direction from the tip to the feeding point of the positive electrode to form a U shape.

  The first horizontal line 12 located at the top of the first element 10 is positioned 15 mm away from the upper side of the opening side of the window flange frame 30 and 15 mm away from the folded line 15, and the first vertical line The strip 11 was positioned 15 mm away from the opening side of the window flange frame 30.

  On the other hand, the second element 20 extends two second horizontal wires 22 each having a wire length of 50 mm in the horizontal direction from the negative feed point 4, and vertically extends downward from the negative feed point 4. The second vertical filament 21 having a length of 45 mm was extended.

  The feeding point 4 of the negative electrode is 15 mm away from the feeding point 3 of the positive electrode and 10 mm away from the vertical length of the opening of the window flange frame 30, and the second vertical line 21 is further from the vertical length of the opening of the window flange frame 30. The position was 15 mm away. The positive electrode feeding point 3 and the negative electrode feeding point 4 were each 10 mm in length and width.

  Further, the central conductor 2a of the coaxial cable 2 extended from a tuner (not shown) was connected to the positive feeding point 3, and the outer conductor 2b was connected to the negative feeding point 4.

  The antenna is printed at a predetermined position on the indoor side of the window glass plate with a conductive paste at a width of 0.7 mm, dried, and baked in a heating bending furnace.

  The antenna of the present embodiment was arranged as an antenna having a frequency of 470 to 710 MHz, which is a terrestrial digital TV broadcast wave, and exhibited frequency characteristics as shown in the frequency characteristic diagram of FIG. The average reception gain of the antenna is −12.9 dBd, which indicates that the antenna has excellent reception characteristics. The antenna of the present embodiment was arranged as an antenna having a frequency of 470 to 710 MHz, which is a terrestrial digital TV broadcast wave, and exhibited frequency characteristics as shown in FIG. The average of the dipole antenna ratio of the reception gain of the antenna is -13.0 dB.

 Second Embodiment FIG. 2 is a modification of the first embodiment shown in FIG. 1, and the positions of the two feeding points are the same as those of the first embodiment shown in FIG.

  Instead of the third horizontal line 13 extending in the horizontal direction from the positive feed point 3 in FIG. 1, the first element 10 extends the first vertical line 11 ′ above the positive feed point 3; It is the same as FIG. 1 except that the first horizontal filament 12 ′ is extended in the horizontal direction from the tip.

  On the other hand, as the second element 20, the length of one upper part of two horizontal filaments extending in the horizontal direction from the negative feed point 4 is set to 20 mm, and the length of the filament is 35 mm above the tip. The auxiliary vertical filament 25 is connected to form an L shape, but the other second horizontal filament 22 is 50 mm as in the first embodiment of FIG. 1, and further vertically downward from the feed point 4 of the negative electrode. The second vertical filament extending to is the same as in the first embodiment.

  Further, the central conductor 2a of the coaxial cable 2 extended from a tuner (not shown) was connected to the positive feeding point 3, and the outer conductor 2b was connected to the negative feeding point 4.

  The antenna is printed with a conductive paste at a predetermined position on the indoor side of the rear window seat side of the side part called the rear quarter of the automobile, with a width of 0.7 mm, and after drying, It was baked in a heating bending furnace.

  The antenna of the present embodiment is arranged as an antenna having a frequency of 470 to 710 MHz, which is a terrestrial digital TV broadcast wave, and the average reception gain of the antenna is -12.5 dBd, and has excellent reception characteristics. I know that there is.

  As mentioned above, although demonstrated by the preferable Example, this invention is not limited to these, A various application is possible.

The figure which shows Example 1 of the glass antenna of this invention. The figure which shows Example 2 of the glass antenna of this invention. FIG. 3 is a frequency characteristic diagram of Example 1 of the present invention. The whole figure which provided the glass antenna of the present invention in the rear quarter window glass of the side of a car.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Window glass 2 Coaxial cable 2a Center conductor 2b Outer conductor 3 Positive feeding point 4 Negative feeding point 10 1st element 11, 11 '1st vertical filament 12, 12' 1st horizontal filament 13 3rd Horizontal strip 14 Third vertical strip 15 Folded strip 20 Second element 21 Second vertical strip 22, 22 'Second horizontal strip 25 Auxiliary vertical strip 30 Window flange frame

Claims (7)

In the antenna for receiving terrestrial digital TV broadcast waves provided at the corner of the window glass on the side of the rear seat of the automobile,
Two feeding points of a positive electrode and a negative electrode provided in the vicinity of the corner portion of the side window glass ,
A first element connected to the positive feed point;
A second element connected to the feeding point of the negative electrode,
The first element includes two filaments connected to the feeding point of the positive electrode,
At least one of the two filaments includes a first vertical filament extending perpendicularly toward a corner direction and a first horizontal line connected to a tip of the first vertical filament. Is connected to the corner of the positive electrode rather than the other wire connected to the feeding point of the positive electrode,
The second element is connected to the negative feed point and extends in the horizontal direction at least two second horizontal filaments, and is connected to the negative feed point and extends in the vertical direction. It consists of filaments,
A glass antenna for a vehicle, wherein a non-grounding type antenna is provided in which a core wire of a coaxial cable and an outer conductor are connected to the positive and negative feeding points, respectively. Of the two filaments constituting the first element , one filament is a filament composed of the first vertical filament and the first horizontal filament, and the other one striatum is connected to a feeding point of the positive electrode, the third vehicle glass antenna according to claim 1, characterized in that the horizontal strip which is extended in the horizontal direction. The third vertical filament is extended in the vertical direction from the tip of the third horizontal filament, and a folded filament is provided that is folded back from the tip of the third vertical filament to the vicinity of the feeding point of the positive electrode. The glass antenna for vehicles according to claim 2 characterized by things. As the first element, two first vertical wires extending in the vertical direction from the feeding point of the positive electrode, and a first horizontal wire extending so as not to intersect each other horizontally and in the same direction from the respective tips. The glass antenna for a vehicle according to claim 1, wherein: Of the two filaments extending in the horizontal direction from the feeding point of the negative electrode, the auxiliary vertical filament is disposed in a direction away from the other second horizontal filament from the tip of one second horizontal filament. The glass antenna for vehicles according to any one of claims 1 to 4 characterized by things. 6. The vehicle according to claim 1, wherein the length of the first element is set to 1 / 4αλ to 3 / 4αλ (α: wavelength shortening rate, λ: wavelength of received radio wave). Glass antenna. 7. The antenna according to claim 1, wherein the antenna comprising the first element and the second element is disposed at each corner of the window glass behind the left and right sides of the vehicle to receive diversity. The vehicle glass antenna according to any one of the above.

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