JP4941158B2 - Glass antenna for vehicles - Google Patents

Description

  The present invention provides a high-sensitivity and stable antenna provided with an ungrounded terrestrial digital TV broadcast wave reception antenna at the corners of the front window glass, rear window glass, and rear side window glass for automobiles. The present invention relates to a glass antenna for a vehicle capable of obtaining reception performance.

  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 negative electrode feeding point is provided on a glass plate surface, and two positive electrode feeding points are provided in the vicinity of both sides of the glass antenna. The central conductor antenna is arranged from each of the positive feed points, the internal conductors of the two coaxial cables are connected to the two positive feed points, and the two external conductors are connected to the negative feed point. A characteristic glass antenna for a vehicle 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 is an antenna for receiving a terrestrial digital TV broadcast wave provided on a window glass of an automobile, wherein two feeding points of a positive electrode and a negative electrode are provided in the vicinity of a corner portion of the window glass, and the feeding point of the positive electrode A first horizontal line extending in a more horizontal direction, and a second vertical line extending in a vertical direction directly from a feeding point of the first vertical line and the positive electrode branching in a vertical direction from a middle portion of the first horizontal line Of the filaments, both the first vertical filament and the second vertical filament are provided, or only the second vertical filament is provided, and the tip of the first vertical filament or A second horizontal wire is connected to the middle part, a first element having a third horizontal wire connected to the tip or middle part of the second vertical wire, and a vertical side from the feeding point of the negative electrode A second element having at least a third vertical filament extending along Rannahli, the positive electrode, each feeding point of the negative electrode, a glass antenna for a vehicle, characterized in that the antenna of the non-grounded type core, and a jacket conductor connected to a coaxial cable, respectively.

  Alternatively, the present invention is the glass antenna for a vehicle described above, wherein a plurality of the third vertical filaments are arranged.

  Alternatively, according to the present invention, the auxiliary horizontal line is extended from the tip of the third vertical line, and is further folded back upward from the tip to the vicinity of the tip of the first horizontal line of the first element. The above-described glass antenna for a vehicle is provided.

  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.

  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 provides a ground frequency of 470 to 710 MHz in which a conductive ceramic paste is provided by printing in the vicinity of a corner portion on the interior surface of the front window glass, rear window glass 1 or rear window glass of an automobile. This is a glass antenna capable of receiving digital television broadcast waves with high performance (see FIGS. 5 and 6).

  As shown in FIGS. 1 to 3, the glass antenna is provided with two feeding points 3, 4 for the positive electrode and the negative electrode in the vicinity of the corner portion of the glass plate 1, and from the feeding point 3 for the positive electrode. 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.

The first element 10 is provided with a first horizontal line 11 extending in the horizontal direction from the positive electrode feeding point 3 , and a first vertical line that branches in a vertical direction from a middle portion of the first horizontal line 11. Of the second vertical wire 13 extending in the vertical direction directly from the wire 12 and the feed point 3 of the positive electrode , both the first vertical wire 12 and the second vertical wire 13 are provided, Alternatively, only the second vertical filament is provided.

Further, a second horizontal line 15 is connected to the tip or middle part of the first vertical line 12, and a third horizontal line 16 is connected to the tip or middle part of the second vertical line 13. Connected.
On the other hand, the second element 20 has at least a third vertical line 21 extending along the vertical side from the feeding point 4 of the negative electrode, and preferably the tip of the third vertical line 21 By providing the auxiliary horizontal filament 22 extending in the horizontal direction, the impedance can be adjusted, whereby the VSWR characteristic is improved and the reception gain is improved.

  Further, it is preferable to fold up the tip of the auxiliary horizontal line 22 to the vicinity of the tip of the first horizontal line 11 of the first element 10 so as to improve the receiving sensitivity.

  In addition, it is preferable to arrange a plurality of the third vertical filaments 21 because the receiving sensitivity is further improved. Furthermore, it is preferable to set the length of the first element 10 to 1 / 4αλ to 3 / 4αλ (α: wavelength shortening rate, λ: wavelength of received radio wave) because the frequency characteristic becomes flat.

  In addition, you may make it provide the glass antenna of invention in the corner part of either the front window glass of a motor vehicle, a rear window glass, and also the window glass of the back side of a side part.

  The first horizontal line 11 and the second horizontal line 15 of the antenna of the present invention are preferably provided at least 5 to 15 mm away from the inside of the flange 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.

  1 to 3 show terrestrial digital television broadcasting having a frequency of 470 to 710 MHz provided in the vicinity of a corner portion of an indoor surface provided in a front window glass, a rear window glass, and a rear window glass of an automobile. It is a glass antenna that can receive waves with high performance.

  When the positions of the feeding points are provided at the four corners of the front window glass, the rear window glass, or the rear window glass of the side part, the ease of wiring work of the coaxial cable 2, the appearance, or the driver's It is also desirable for visibility outside the vehicle through the window glass.

  Further, when the antenna of the present invention is provided on the front window glass of an automobile, it is preferably provided at the corner portion on the upper side so as not to obstruct the driver's view as shown in FIG.

  Further, when the antenna of the present invention is provided on the rear window glass of the automobile, it is preferable to provide it at the four corners which do not adversely affect the defogger as shown in FIG. 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 which are the antennas of the present invention are separated from the inside of the opening of the flange by 5 to 15 mm from the flange so as not to be affected by the metal body. Although it is better to separate the antenna and feed point from the flange and move too far to the inside, new problems such as conspicuous wiring of the coaxial cable and interference with defogger and other antennas may occur. It is to do.

Further, by providing the first horizontal filament 11 of the first element 10, the frequency characteristic becomes flat, and the first vertical filament 12 and the positive electrode branch in the vertical direction from the middle portion of the first horizontal filament 11. Of the second vertical filaments 13 extending in the vertical direction directly from the feeding point , both the first vertical filaments 12 and the second vertical filaments 13 are provided, or the second vertical filaments are provided. 13, and further, a second horizontal filament 15 is connected to the tip or middle part of the first vertical filament 12, and a third part is coupled to the tip or middle part of the second vertical filament 13. By connecting the horizontal line 16, the receiving sensitivity of the antenna can be greatly improved.

  Examples of the present invention and comparative examples will be described below.

  [Embodiment 1] The glass antenna of the present invention is disposed at one corner of the upper margin of the defogger of the rear window glass of an automobile as shown in FIG.

  Two feeding points 3 and 4 of a positive electrode and a negative electrode are provided close to the corner of the glass plate 1, and a first horizontal line having a line length of 220 mm along the upper side of the glass plate 1 from the feeding point 3 of the positive electrode. A strip 11 is provided, and a first vertical strip 12 having a strip length of 5 mm branched from a middle portion of the first horizontal strip 11 is provided, and left and right from the lower end of the first vertical strip 12. A second horizontal filament 15 having a filament length of 210 mm was provided in both horizontal directions.

  Further, a second vertical line 13 having a line length of 60 mm is extended in the vertical direction from the feeding point 3 of the positive electrode, and a third horizontal line 16 having a length of 100 mm in both the left and right horizontal directions from the tip part thereof. Connected. In addition, the feed point 3 of the positive electrode and the first horizontal filament 21 were positioned 15 mm away from the opening side of the flange.

  Further, two third vertical wires 21 having a wire length of 60 mm are extended in the vertical direction from the feed point 4 of the negative electrode, and the feed point 4 of the negative electrode and the third vertical wire 21 are extended from the longitudinal side of the opening of the flange. The position was 15 mm away.

  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 FIG. The average of the dipole antenna ratio of the reception gain of the antenna is -13.0 dB.

[Reference Example] Similar to Example 1, as shown in FIG. 2, two feeding points 3 and 4 for the positive electrode and the negative electrode are provided close to the corner portion of the glass plate 1, and the glass is formed from the feeding point 3 for the positive electrode. A first horizontal filament 11 is provided along the upper side of the plate 1, and a first vertical filament 12 having a filament length of 100 mm branched from a middle portion of the first horizontal filament 11 is provided, A third horizontal filament 15 having a filament length of 120 mm was provided in the horizontal direction from a position 15 mm below the upper end of the first vertical filament 12.
In addition, the filament length which does not describe length is the same as Example 1 of FIG.

  Further, there is only one third vertical line 21 extending in the vertical direction from the negative electrode feeding point 4, and the length of the line is the same as that of the first embodiment shown in FIG.

  The spacing between the positive electrode feeding point 3, the negative electrode feeding point 4, the first horizontal filament 21, the third vertical filament 21, and the flange opening side is the same as that of the first embodiment of FIG. It is the position.

  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 this reference example is arranged as an antenna having a frequency of 470 to 710 MHz, which is a terrestrial digital TV broadcast wave, and the average of the dipole antenna ratio of the reception gain is -13.0 dB, and has excellent reception characteristics. It can be seen that it is.

[Embodiment 2 ] As shown in FIG. 3, two feeding points 3 and 4 of a positive electrode and a negative electrode are provided close to the corner portion of the glass plate 1, and the positive electrode feeding point 3 is used as the first element 10. A first horizontal line 11 having a line length of 190 mm is disposed along the upper side of the glass plate 1, and a second vertical line having a line length of 60 mm in the vertical direction from the feeding point 3 of the positive electrode. The filament 13 was extended, and a third horizontal filament 16 having a length of 50 mm was extended in the horizontal direction from the tip.

  Further, as the second element 20, a third vertical line 21 having a line length of 60 mm is extended in the vertical direction from the feeding point 4 of the negative electrode, and a horizontal auxiliary having a line length of 200 mm in the horizontal direction from the tip thereof. The filament 22 was extended, and further folded back upward from the tip thereof to provide a vertical filament that was folded back to the vicinity of the tip of the first horizontal filament of the first element. The other filaments are the same as in Example 1 in FIG.

  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 this 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 of the dipole antenna ratio of the reception gain is -13.0 dB, and has excellent reception characteristics. It can be seen that it 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 the reference example 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 front window glass of a car. The whole figure which provided the glass antenna of the present invention in the rear window glass 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 First element 11 First horizontal filament 12 First vertical filament 13 Second vertical filament 15 Second Two horizontal filaments 16 Third horizontal filament 20 Second element 21 Third vertical filament 22 Horizontal auxiliary filament 30 Window frame 40 Defogger

Claims (4)

An antenna for receiving terrestrial digital TV broadcast waves provided on a window glass of an automobile, provided with two feeding points of a positive electrode and a negative electrode in the vicinity of a corner portion of the window glass, and a first horizontal direction from the feeding point of the positive electrode. Of the first vertical filament branched in the vertical direction from the middle portion of the first horizontal filament and the second vertical filament extended in the vertical direction directly from the feeding point of the positive electrode , Both the first vertical line and the second vertical line are provided, or only the second vertical line is provided. Of the first vertical line connected to the tip or middle part of the second vertical line, and the first element extending along the vertical side from the feeding point of the negative electrode. A second element having at least three vertical filaments, the positive electrode, Each feeding point electrode, the glass antenna for a vehicle, characterized in that the antenna of the non-grounded type core, and a jacket conductor connected to a coaxial cable, respectively. The glass antenna for a vehicle according to claim 1, wherein a plurality of the third vertical filaments are arranged. The auxiliary horizontal line is extended from the tip of the third vertical line, and is further turned back from the tip to provide a folded vertical line to the vicinity of the tip of the first horizontal line of the first element. The glass antenna for a vehicle according to claim 1 or 2. 4. 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). 5. Glass antenna.

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