JP5402345B2 - Glass antenna for vehicles - Google Patents

Description

  The present invention relates to a glass antenna for a vehicle in which a non-grounding type digital terrestrial TV broadcast wave receiving antenna is provided on a side window glass for an automobile so as to obtain a highly sensitive and stable receiving 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.

  For example, JP 2002-299932 A discloses a first element having at least a line provided along an opening side from a first feeding point provided at a corner of an opening of a side window glass for a vehicle. , Having a line provided so as to be closer to a line extending from the power supply point of the first element than the second power supply point provided in the vicinity of the first power supply point, and having the length as the reception frequency Λ / 4 or less (λ: wavelength) of the second element, and the first element and the second element are capacitively coupled close to each other in the vicinity of the feeding point, respectively, and the coaxial cable inner conductor and outer There is described a glass antenna for a vehicle characterized in that it is connected to a conducting wire to form a non-grounded balanced antenna (Patent Document 1).

  Further, for example, in Japanese Patent Application Laid-Open No. 2002-64317, in a vehicle glass antenna for a TV wavelength band disposed on a side glass of a vehicle, the glass antenna is a first disposed near one corner of the side glass. Extending from a feeding point, extending from a first antenna disposed along the outer periphery of the side glass, and a second feeding point disposed in the vicinity of the first feeding point, on the inside of the first antenna, A second antenna having a trapezoidal loop, and the first antenna is formed with a plurality of antenna conductors substantially in parallel, and the first antenna and the second antenna are in a TV wavelength band. A glass antenna for a vehicle that is capacitively coupled is described (Patent Document 2).

JP 2002-299932 A JP 2002-64317 A

  Although the antenna disclosed in Patent Document 1 is a non-grounded antenna provided on a side window glass of an automobile, it is an antenna for receiving radio waves of AM / FM radio broadcast waves and analog television broadcast waves. However, although the area occupied by the antenna is reduced, there is a problem that it is still not sufficient.

  Further, the antenna disclosed in Patent Document 2 is an antenna for receiving a separate grounded analog television broadcast wave in which each of the antennas 41 and 42 provided on the side window glass of the automobile is independent. It is not an antenna for receiving radio waves for ungrounded digital terrestrial television that is formed by integrating two antennas into a single antenna.

  The present invention has been made to solve such problems. An antenna for an ungrounded digital terrestrial television set is provided in a narrow space of a side window glass plate for an automobile, and the antenna is occupied. An object of the present invention is to reduce the area, reduce variations in reception gain without deteriorating antenna performance, and obtain a highly sensitive and stable reception gain.

That is, the present invention is a glass antenna for receiving a terrestrial digital TV broadcast wave provided on a side window glass of an automobile, and a core wire side feeding point and a ground side feeding point are close to the upper side or corner vicinity of the side window glass. A core-side element extending in a direction opposite to the ground-side feed point along the flange frame from the core-side feed point, and a direction opposite to the core-side feed point along the flange frame from the ground-side feed point consists of two elements of the ground-side elements extending in a non-grounded type antenna, and the extreme projecting end portions of the two elements is arranged so as butted to each other, the core wire side element, said A glass antenna for a vehicle comprising at least one filament extending along a flange frame or only a closed loop filament .

  Alternatively, according to the present invention, the wire length of the core wire side element is αλ / 4 (α: wavelength reduction rate of glass plate, λ: wavelength of received radio wave), and at least one wire or closed loop wire The above-described glass antenna for a vehicle, characterized by comprising:

  Alternatively, according to the present invention, the grounding side element is substantially U-shaped consisting of a plurality of wires connected in series, and the total length of each wire is 3αλ / 4 (α: wavelength reduction rate of glass plate, λ : The wavelength of the received radio wave), and the first wire extending from the ground-side feeding point of the ground-side element is close to the flange frame, and the length thereof is αλ / 4. Glass antenna.

  Alternatively, the present invention is the glass antenna for a vehicle described above, wherein one of the plurality of filaments of the ground side element is a horizontal filament having a filament length αλ / 4.

  Alternatively, the present invention is the above-described glass antenna for a vehicle, comprising a folded wire provided close to the horizontal wire from a tip of the horizontal wire of the ground side element and keeping a predetermined interval.

  According to the present invention, the area occupied by the antenna and the variation of the reception gain of the antenna, which have been problems in the past, are improved, and even in a limited narrow space such as a side window glass for automobiles, digital terrestrial An ungrounded antenna for TV broadcast waves can be installed, and high-sensitivity and stable reception performance can be obtained.

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. The figure which shows Example 3 of this invention 3 glass antenna. The figure which shows Example 4 of the glass antenna of this invention. The figure which shows Example 5 of the glass antenna of this invention. The frequency characteristic figure when the space | interval a of the 1st filament and the flange frame of Example 1 of this invention is 10 mm and 20 mm. The frequency characteristic figure when the space | interval b of the folding line | wire and horizontal line | wire of Example 1 of this invention is 5 mm and 20 mm.

  In the present invention, a glass antenna pattern provided on the interior surface of a relatively small area fitting window glass called a rear quarter part on the rear seat side of the side window glass 1 of an automobile is printed with a conductive ceramic paste. A glass antenna that is provided and capable of receiving radio waves in the terrestrial digital television broadcast wave band having a frequency of 470 to 710 MHz with high performance.

  As shown in FIG. 1 to FIG. 5, a glass antenna for receiving terrestrial digital TV broadcast waves provided on a side window glass 1 of an automobile, in which a core side feeding point 3 and a ground side feeding point 4 are connected to the side window glass. A core wire side element 10 provided in the vicinity of the upper side or corner vicinity of one flange frame 5 and extending from the core wire side feed point 3 along the flange frame 5 in a direction opposite to the ground side feed point 4; A non-grounded antenna comprising two elements of a ground side element 4 extending from the feed point 4 along the flange frame 5 in a direction opposite to the core side feed point 3, and the most projecting end of the two elements It is the glass antenna for vehicles arrange | positioned so that parts may mutually face.

  The most projecting end portion indicates the tip end portion of the filament of the core wire side element 10 for the core wire side element 10 and basically the horizontal line that is the tip of the substantially U-shaped strip for the ground side element 20. Although it is set as the front-end | tip part of the strip | line 23, when the folding line 25 is above the horizontal line | wire 23, the front-end | tip part of the vertical line 24 is shown.

  The core wire-side element 10 has a length of αλ / 4, where α is the wavelength shortening rate of the glass plate and λ is the wavelength of the received radio wave, and it has at least one wire or a substantially rectangular shape. Consists of closed loop filaments.

  On the other hand, the ground side element 20 is formed by connecting a plurality of wires in series to form a substantially U shape, and the total length of the ground side element 20 is 3αλ / 4 (α: wavelength reduction rate of glass plate, λ: And the length of the wire (first wire) close to the flange frame 5 in the wire extending from the ground-side feed point of the ground-side element is αλ / 4, and the ground-side feed The first filament 21 extended from the point 4 along the flange frame may be two filaments, and the ends may be connected to form a rectangular loop.

  Each of the plurality of lines connected in series of the ground side element 20 is a substantially U-shaped broken line, and one of the lines is a horizontal line 23 having a length of αλ / 4. A folded line 25 or 25 ′ may be provided so as to be refracted from the tip of the line 23 and to be close to the horizontal line 23 with a predetermined distance through the vertical line 24.

  The folded line 25 may be on either the upper side or the lower side of the horizontal line 23 as long as it is provided close to the horizontal line 23 with a predetermined distance a.

  The antenna is printed on a side surface of the window glass plate 1 with a conductive ceramic paste with a width of about 0.7 mm, dried, and baked in a heating furnace.

  The core wire side feed point 3 and the ground side feed point 4 are respectively connected to a coaxial cable core wire and a ground wire and connected to a terrestrial digital broadcast wave receiving tuner (not shown), and have a frequency of 470 to 710 MHz which is a terrestrial digital TV broadcast wave. Arranged as an antenna.

[First Embodiment]
As shown in FIG. 1, a core wire feeding point 3 is provided in the vicinity of the upper corner portion of a substantially triangular rear quarter window provided on the rear side of a side window glass 1 of an automobile, and a flange is provided in the vicinity of the core wire feeding point 3. A ground-side feeding point 4 is provided in the vicinity of the position along the upper side of the frame 5.

  The core wire side element 10 is provided in the counterclockwise direction along the flange frame 5 from the core wire side feed point 3, and its length is α for the wavelength reduction rate of the glass plate, λ for the wavelength of the received radio wave, Assuming that the wavelength shortening rate α is 0.7, αλ / 4 = 50 to 200 mm, and it is disposed along the flange frame 5 so as to be close to the flange frame 5 in the range of 5 to 20 mm.

  On the other hand, the grounding side element 20 is provided with a strip in the clockwise direction along the flange frame 5 from the grounding side feeding point 4, and the shape thereof is substantially U-shaped. The substantially U-shaped grounding side element 20 is defined as a first strip 21 which is a linear portion extending from the grounding side feeding point 4 along the flange frame 5 and close to the inside of the flange frame 5, and the length thereof is as follows. When the wavelength shortening rate of the glass plate is α, the wavelength of the received radio wave is λ, and the wavelength shortening rate α of the glass is 0.7, αλ / 4 = 50 to 200 mm.

  The first wire 21 of the grounding side element 20 and the inner side of the flange frame are preferably arranged along the flange frame 5 so that the distance a thereof is close within a range of 5 to 20 mm. When the distance a indicated by the solid line is 10 mm, the receiving gain is further improved compared to the case where the distance a indicated by the dotted line is 20 mm. It can be seen that it is desirable that the distance a from the inner side of the is narrower.

  The second wire 22 (length = 10 to 80 mm) is extended in a direction away from the flange frame 5 from the tip of the first wire 21, and from the tip of the second wire 22 toward the ground-side feeding point 4 side, A horizontal line 23 (length αλ / 4 = 50 to 200 mm) is extended in the horizontal direction, and the first line 21, the second line 22, and the horizontal line 23 are arranged in series to form a substantially U-shape. It was.

  Further, a vertical wire 24 of 5 to 20 mm is provided clockwise from the tip of the horizontal wire 23, that is, in a direction approaching the tip of the core wire-side element 10, and the horizontal wire 23 is provided from the tip of the vertical wire 24. The 5 to 80 mm folded wire 25 is extended in parallel, the total length of each wire from the ground-side feeding point 4 to the ground-side element 20, the wavelength reduction rate of the glass plate is α, the wavelength of the received radio wave is λ, The wavelength shortening rate was α, which was 3αλ / 4, 200 to 300 mm.

  The horizontal line 23 and the folded line 25 of the ground-side element 20 are preferably arranged in parallel so that the distance b is close within a range of 5 to 20 mm, but as shown by the solid line in FIG. It can be seen that the reception gain is further improved when the interval is 5 mm than when the interval indicated by the dotted line is 20 mm. That is, it is preferable that the distance b between the horizontal line 23 and the folded line 25 is narrowed because a high reception gain is obtained.

  The tip end portion of the vertical wire 24 that is the most projecting end portion of the grounding side element 20 and the tip end portion of the core wire side element were arranged so as to face each other like both hands of the heel.

  The antenna is printed on the interior side surface of the window glass plate with a conductive ceramic paste in a width of about 0.7 mm, dried, baked in a heating furnace, the core wire side feeding point 3, the ground side A coaxial cable core and ground wire are connected to the feed point 4 and connected to a terrestrial digital broadcast wave receiving tuner (not shown). When a radio wave having a frequency of 470 to 710 MHz, which is a terrestrial digital TV broadcast wave, is received, it is in a practical level. Reception performance was obtained.

[Second Embodiment]
The second embodiment shown in FIG. 2 is the same as that of the first embodiment shown in FIG. 1 except that the number of the filaments of the core wire side element 10 extending from the core wire feeding point 3 of the first embodiment shown in FIG. The ground side element 20 is exactly the same as that of the first embodiment.

  By setting the number of the filaments of the core wire side element 10 to two, the capacitive coupling with the metal flange frame 5 is improved, and the reception gain performance of the antenna can be improved.

[Third Embodiment]
In the third embodiment shown in FIG. 3, the number of the filaments of the core wire side element 10 extending from the core wire side feeding point 3 of the first embodiment shown in FIG. Except for the closed-loop rectangular shape, the second embodiment is the same as the first embodiment shown in FIG. 1, and the grounding side element 20 is the same as the first embodiment.

  By making the core wire side element 10 into a closed loop rectangular shape, it becomes equivalent to a wide band-like element. As a result, the capacitive coupling with the metal flange frame 5 is improved, and the reception gain performance of the antenna is improved. I was able to do it.

[Fourth Embodiment]
In the fourth embodiment shown in FIG. 4, the number of first filaments 21, which is a portion adjacent to the flange frame 5 of the ground-side element 20 that extends from the ground-side feeding point 4 of the first embodiment shown in FIG. 1. 1 is the same as that of the first embodiment shown in FIG. 1 except that the two ends are connected to each other and the ends thereof are connected to form a closed loop rectangular shape. The form is exactly the same.

  Since the first linear portion 21 adjacent to the flange frame 5 of the ground-side element 20 has a closed-loop rectangular shape, it is equivalent to a wide strip-shaped element. As a result, capacitive coupling with the metal flange frame 5 is achieved. As a result, the reception gain performance of the antenna can be improved.

[Fifth Embodiment]
In the fifth embodiment shown in FIG. 5, grounding other than that in which the folded wire 25 ′ of the grounding side element 20 of the first embodiment shown in FIG. 1 is folded under the horizontal wire 23. Each filament of the side element 20 and the core wire side element 10 are exactly the same as those in the first embodiment.

  The folded line 25 ′ is a position close to the lower side of the horizontal line 23 of the ground side element 20, but an antenna reception gain almost equal to that of the first embodiment was obtained.

  The operation of the present invention will be described below.

  When the first filament 21 of the grounding side element 20 of the present invention is brought close to the flange frame 5 of the metal body of the automobile within a range of 5 to 20 mm, the capacity coupling with the flange frame 5 is improved, and the entire vehicle is By using the radio wave mounted on the vehicle as an antenna, the reception gain can be improved and the reception performance can be stabilized. Further, similarly, the core-side element 10 has the same effect as that received by the ground-side element 20 from the vehicle main body by being brought close to the flange frame 5 of the metal body of the automobile within a range of 5 to 20 mm. Gain can be improved.

  The reason why the core-side element 10 should be arranged counterclockwise and the ground-side element 20 should be arranged clockwise so that the most projecting end portions are attached to each other is that the core-side element This is because the receiving performance is stabilized by arranging both elements so that 10 is surrounded by the ground side element 20 capacitively coupled to the flange frame 5.

  The reason why the horizontal line 23 of the substantially U-shaped line of the ground side element 20 is made horizontal is that the radio wave of the terrestrial digital TV broadcast wave generally flies in the horizontally polarized wave. This is because it is possible to efficiently receive incoming radio waves.

  As mentioned above, although each embodiment of this invention was described, this invention is not limited to these, A various application is possible.

DESCRIPTION OF SYMBOLS 1 Window glass 3 Core wire side feeding point 4 Ground side feeding point 5 Flange frame 10 Core wire side element 20 Ground side element 21 1st wire 22 2nd wire 23 Horizontal wire 25 Folding wire

Claims (5)

A terrestrial digital TV broadcast wave receiving glass antenna provided on a side window glass of an automobile, wherein a core wire side feeding point and a ground side feeding point are provided close to the upper side or corner vicinity of the side window glass, and the core wire side A core wire-side element extending in a direction opposite to the ground-side feed point from the feed point along the flange frame, and a ground-side element extending in a direction opposite to the core wire-side feed point from the ground side feed point along the flange frame The two elements are non-grounded antennas, the most projecting ends of the two elements are arranged to face each other, and the core wire side element extends along the flange frame. A glass antenna for a vehicle comprising only at least one filament or a closed loop filament . The wire length of the core wire side element is αλ / 4 (α: wavelength reduction rate of glass plate, λ: wavelength of received radio wave), and is composed of at least one wire or a closed loop wire. The glass antenna for a vehicle according to claim 1. The ground side element is substantially U-shaped consisting of a plurality of filaments connected in series, and the total length of each filament is 3αλ / 4 (α: wavelength reduction rate of glass plate, λ: wavelength of received radio wave), 3. The vehicle according to claim 1, wherein the first wire extending from the ground-side feeding point of the ground-side element is close to the flange frame and has a length of αλ / 4. Glass antenna. 4. The glass antenna for a vehicle according to claim 1, wherein one of the plurality of wires of the grounding side element is a horizontal wire having a wire length of αλ / 4. The glass antenna for a vehicle according to claim 4, further comprising a folded wire provided close to the horizontal wire from a tip of the horizontal wire of the grounding side element and maintained at a predetermined interval.

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