JP2006165933A - Glass antenna for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce the occupancy area of an antenna, and to obtain highly sensitive and stable receiving performance by preventing two system antennas arranged side by side from affecting each other even when two system non-ground type antennas are adjacently arranged side by side in the narrow space of the window glass board of an automobile. <P>SOLUTION: This glass antenna for a vehicle is configured by arranging two system non-ground type antennas whose conductive filaments are extended from the respective power feeding points of a positive pole and a negative pole on the same glass surface for diversity-receiving those two system antennas. In this case, the power feeding point of one negative pole is arranged on a glass plate surface and the power feeding points of two positive poles are arranged in the neighboring positions of the both sides, and an outer cover conductor antenna is extended from the power feeding point of the negative pole, and a central conductor antenna is arranged from each of the two positive pole power feeding points, and the internal conductors of the two coaxial cables are respectively connected to the power feeding points of the two positive poles, and the two external conductors are connected to the power feeding point of the negative pole, and the power feeding point of the negative pole is used as the common power feeding point of the two system antennas, and the antenna extended from the power feeding point is used as a shared antenna. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  In the present invention, when two ungrounded UHF band TV broadcast wave antennas are arranged close to each other in a narrow space of an automobile window glass plate, the antennas do not adversely affect each other. The present invention relates to a glass antenna for a vehicle capable of obtaining 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, extend only the internal conductor from the connection position of the metal body by 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. There was a point.

  As a countermeasure, in the coaxial cable wiring for the high frequency telephone band, the external conductor and the internal conductor of the coaxial cable are separated in the vicinity of the glass antenna, and each is connected to a feeding point of a separate antenna wire, High stability and high sensitivity can be realized by combining these with a non-grounded antenna in one system.

  However, in the case of an ungrounded antenna, since both the outer conductor and the inner conductor of the coaxial cable are connected to different antenna strips, when two or more antennas are provided on the same glass surface, a plurality of coaxial antennas are used. There is a problem that a feeding point is required for each of the external and internal conductors of the cable, the total number of feeding points of the antenna system is increased, and the antenna wire is disposed from each feeding point, which is complicated.

  Furthermore, TV broadcast waves are currently shifting from terrestrial analog broadcasts to terrestrial digital broadcasts, and it is necessary for automobiles to respond to digital terrestrial broadcasts for transmission / reception devices for broadcast radio waves. It is expected that both terrestrial analog broadcast and terrestrial digital broadcast systems will be installed. In this case, it is necessary to prepare both antennas so that both systems can handle each system. In particular, a high-sensitivity antenna is required compared to the transmission / reception of terrestrial analog broadcasting, and an ungrounded antenna must be adopted as the antenna system. An area was required.

  As the non-grounded antenna, for example, in Japanese Patent Laid-Open No. 7-46016, a plurality of non-grounded antennas are provided in the upper margin part or the lower margin part of the antifogging heating filament of the rear window glass of the automobile. A window glass antenna for a car phone is described.

As an improvement of the terminal structure for connecting the plurality of coaxial cables to a plurality of antennas, for example, in Japanese Patent Laid-Open No. 9-275307, a plurality of external conductor coupling electrodes having an electrical length of ¼ wavelength are connected to a plurality of terminals. The outer conductors of the coaxial cable are connected in common, the inner conductors of the plurality of coaxial cables are connected to the plurality of center conductor coupling electrodes, and the outer conductor coupling electrode is disposed between the plurality of center conductor coupling electrodes. A coupling device and an antenna device for a coaxial cable are described in which a pair of outer conductor coupling electrodes is sufficient when a plurality of coaxial cables are connected by electrically separating the coupling electrodes (Patent Document 2). .
JP 7-46016 A JP-A-9-275307

  As already described, the non-grounded antenna as disclosed in Japanese Patent Laid-Open No. 7-46016 has a plurality of coaxial cables in order to connect both the external conductor and the internal conductor of the coaxial cable to separate antennas. Not only will the total number of cable terminals increase and become complicated, but if multiple antennas are placed side by side in a limited space, both antennas will be placed close together and will adversely affect each other. However, there is a problem that the effect cannot be obtained even if it is performed, and there is a problem that the antenna must be arranged at positions distant from each other, and in this case, the coaxial cable has to be installed to various places on the glass plate.

  On the other hand, the above-mentioned Japanese Patent Laid-Open No. 9-275307 improved the terminal structure allows connection between a plurality of coaxial cables and wireless devices installed inside and outside a sealed space such as a vehicle or a room without providing a through hole. It is an improved patent for a coupling device and an antenna device for coaxial cables that are made possible, and the patent described in the publication describes a non-grounded two-system glass antenna provided on the indoor surface of a window glass for a vehicle such as an automobile. The feeding point and the antenna element are not provided on the same surface of the window glass plate.

  The present invention has been made to solve such problems, and even if two ungrounded antennas are arranged in close proximity in a narrow space of a window glass plate for an automobile, The two antennas installed do not adversely affect the reception performance of each other, reducing the area occupied by the antenna, providing highly sensitive and stable reception performance, and easy installation of coaxial cables The purpose is to be able to.

  That is, the present invention provides a glass antenna for a vehicle in which 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, and the two antennas receive diversity. , One negative electrode feed point on the glass plate surface and two positive electrode feed points in the vicinity of both sides thereof, the outer conductor antenna extending from the negative electrode feed point, and a central conductor antenna from each of the two positive electrode feed points Is a glass antenna for a vehicle, characterized in that the inner conductors of two coaxial cables are connected to two positive feed points, respectively, and the two outer conductors are connected to a negative feed point. .

  Alternatively, in the present invention, the outer conductor antenna has at least a horizontal filament, and the length thereof is set to 1 / 4αλ to 3 / 4αλ (α: wavelength reduction rate of glass plate, λ: wavelength of received radio wave). This is the glass antenna for a vehicle described above.

  Alternatively, the present invention is characterized in that the two central conductor antennas are at the upper and lower both sides of the horizontal conductor of the outer conductor antenna and have at least a horizontal filament extending from each of the two positive feed points. It is the glass antenna for vehicles mentioned above.

    Alternatively, in the present invention, the length of the antennas of the two positive electrodes is set to 1 / 4αλ to 3 / 4αλ (α: wavelength shortening rate, λ: wavelength of received radio wave). It is a glass antenna.

  Even if two non-grounded antennas, particularly UHF band TV broadcast wave antennas, are arranged in close proximity in a narrow space on a window glass plate for automobiles, the two antennas arranged side by side have an adverse effect on each other. High sensitivity and stable reception performance can be obtained without affecting the frequency.

  In addition, the negative electrode feed point and the outer conductor antenna element of the two non-grounded antennas are shared, and the outer conductor antenna is extended from each of the two positive electrode feed points provided near both sides of the negative electrode feed point. Therefore, the area occupied by the entire antenna can be reduced, and moreover, conventionally, feeding of two antennas provided at the upper and lower margins of the defogger of the window glass plate or at the left and right ends of the upper and lower margins is provided. Since the points can be provided close to each other, it is easy to install the coaxial cable.

  As shown in FIG. 9, two systems of non-grounded antennas are arranged on the same indoor surface of the window glass 1 of an automobile, and in the glass antenna for diversity reception of the two systems of antennas, one shared on the glass plate surface. A negative feed point 4 and two positive feed points 3 and 3 ′ are provided at positions near both sides of the negative feed point 4. The outer conductor antenna 8 is extended from the negative feed point 4, and the central conductor antenna 7 is connected to each of the two positive feed points. 7 ′.

  As shown in FIG. 1, two coaxial cables 2 and 2 extending from a tuner (not shown) are connected to the central conductors 2 a and 2 a of the positive electrode feeding points 3 and 3 ′, respectively. The two outer conductors 2b and 2b ′ were collectively connected to one negative electrode feeding point 4.

  The center conductors 2a, 2a and the outer conductors 2b, 2b of the two systems of coaxial cables are separated in the vicinity of the feeding points 3, 3 ', 4.

  This is the total length of the antenna line from the separation point of the center conductor 2a and the outer conductor 2b to the tip of the antenna line on the glass plate.

  For this reason, when the length of the lead wire from the separation point of the central conductors 2a, 2a and the outer conductors 2b, 2b of the coaxial cable to the feeding points 3, 3 ′, 4 is increased, only the lead wire can be used as an antenna line. Therefore, the length of the antenna line on the glass plate is shortened, and the antenna may not be installed on the glass plate surface at a high frequency such as a TV broadcast wave UHF band.

  For this reason, the lead wire length from the separation point to the feeding point on the glass plate is shortened by separating the power supply points 3, 3 ′ and 4 near, and the length of the antenna line on the glass plate surface is reduced. It is necessary to obtain a stable reception performance for a long time.

  The negative feed point 4 is a common feed point for the two antennas. The outer conductor antenna 8 extending from the feeding point is a shared antenna on the minus side of the two antennas.

  The outer conductor antenna 8 preferably has at least horizontal stripes and has a length of 1 / 4αλ to 3 / 4αλ (α: wavelength shortening rate, λ: wavelength of received radio wave).

  The wavelength shortening rate α means that when a radio wave (high-frequency current) propagates to an insulator such as a glass plate having a dielectric constant and permeability higher than that of a vacuum, the propagation speed becomes slow due to the influence of the insulator substance. In the case of a glass plate, α is usually about 0.6 to 0.8.

  Furthermore, the two central conductor antennas 7 and 7 ′ are located at both the upper and lower positions of the horizontal conductor portion of the outer conductor antenna 8, and at least a horizontal line extending from each of the two positive electrode feeding points 3 and 3 ′. Have.

  The lengths of the two central conductor antennas 7 and 7 'are preferably set to 1/4 αλ to 3 / 4αλ (α: wavelength shortening rate, λ: wavelength of received radio wave).

  The positions of the feeding points 3, 3 ′ and 4 are positions in the vicinity of the left and right edges of the upper margin part or the lower margin part of the defogger of the rear window glass 1, that is, positions where the bus bars of the defogger are extended upward or downward. It is desirable in terms of ease of wiring work of the coaxial cables 2 and 2 or appearance.

  Although the center conductor antenna 7 is linear in FIG. 1, the end of the horizontal line extending from the feeding point 3 may be once bent upward or downward and then folded back toward the feeding point.

  The outer conductor antenna 8 may be configured such that the tip of a horizontal line extending from the feeding point 3 is once branched and bent in both the upper and lower directions as shown in FIGS. 2 and 3 and then folded back to the respective feeding points. In this case, when the outer conductor antenna 8 is installed between the two systems of the central conductor antennas 7 and 7 ', the folded conductor is separated from the horizontal conductor of the center conductor antennas 7 and 7' by an interval of about 3 to 10 mm. You may make it adjoin.

  Alternatively, the outer conductor antenna 8 may have a rectangular shape as shown in FIG. 4, and the rectangular outer conductor antenna 8 may be sandwiched between the two central conductor wires 7 and 7 ′.

  In this case, the outer conductor antenna 8 has a closed-loop rectangular shape, but it may be an open loop, and the occupied area of the outer conductor antenna 8 is larger than the area of the antenna composed of the horizontal stripes. Thus, the influence of the central conductor wires 7 and 7 'on each other is smaller than that of the case, and a decrease in reception sensitivity can be prevented.

  Alternatively, as shown in FIG. 5, the tip of the horizontal line extending from the feeding point 4 is once branched and bent in both the upper and lower directions, and further provided with a line that is folded back toward the respective feeding point, It is also possible to extend the filament so as to surround the 7 ′ and positive feed points 3 and 3 ′ and connect it to the negative feed point 4 so that the outer conductor antenna has an eight-shaped loop shape.

  FIG. 9 shows an example in which the antenna of the present invention is provided in the upper margin portion or the lower margin portion of the defogger of the rear window glass of the automobile. Reference numeral 12 denotes an antenna for another frequency band.

  When diversity reception is performed using four antennas in combination of two antennas provided in the upper margin part and the lower margin part, the reception characteristics become more preferable.

  The operation of the present invention will be described below.

  By connecting the outer conductor 2 b of the coaxial cable 2 to the feeding point 4, the potential of the outer conductor antenna 8 connected to the feeding point 4 is lowered. As a result, radio waves (high-frequency current) emitted from the central conductor antennas 7 and 7 ′ connected to the feeding points 3 and 3 ′ having a high potential flow to the outer conductor antenna 8 connected to the feeding point 4 having a low potential. .

  For this reason, if the central conductor antennas 7 and 7 'connected to the two coaxial cables 2 and 2 are arranged on both sides of the outer conductor antenna 8, they are connected to the feeding point 3 and the feeding point 3'. The central conductor antennas 7 and 7 ′ have almost no adverse effects such as a decrease in reception, and two antennas can be arranged close to each other.

  Thus, by connecting the outer conductors 2b and 2b of the two coaxial cables 2 and 2 to the feeding point 4, the total number of feeding points arranged on the window glass 1 can be reduced. 4 and the skin conductor antenna 8 are shared, the area occupied by the entire two systems of antennas including the center conductor antennas 7 and 7 and the skin conductor antenna 8 can be reduced.

  As shown in FIGS. 2 and 3, when the folded line of the low-potential outer conductor antenna 8 is disposed so as to be close to the two central conductor antennas 7 and 7 ′ having a high potential, the central conductor antennas 7 and 7 ′ are disposed. Therefore, the radio wave (high-frequency current) easily flows from the low-potential outer skin conductor 8 side, so that the central conductor antennas 7 and 7 'do not adversely affect each other, such as a decrease in reception.

  As shown in FIG. 5, when the outer conductor antenna 8 having a low potential is formed in a loop shape so as to surround the two central conductor antennas 7 and 7 'having a high potential, the influences of the central conductor antennas 7 and 7' on each other can be affected. Less preferred.

Examples of the present invention and comparative examples will be described below.
[Example 1]
Two systems of glass antennas as shown in FIG. 1 are arranged at the left end positions of the upper margin part or the lower margin part of the defogger of the rear window glass of the automobile as shown in FIG.

  The two antennas are provided with a common negative electrode feeding point 4 on the same surface of a glass plate and two positive electrode feeding points 3 and 3 ′ in the vicinity of both upper and lower sides thereof. The conductor antenna 8 was extended in the horizontal direction, and the center conductor antennas 7 and 7 ′ having horizontal stripes from the two positive electrode feeding points were disposed.

  Further, the central conductors 2a and 2a of the two coaxial cables 2 and 2 extending from the tuner are separately connected to the positive feed points 3 and 3 ', respectively, and the outer conductors 2b and 2b of the two coaxial cables 2 and 2 are connected. About ', it connected to the feed point 4 of one negative electrode collectively.

  The width | variety of each filament of a present Example is 0.7 mm, and the length and space | interval of this filament are as follows.

The length of the line of the central conductor antenna 7 = 90 mm,
Length of filament of outer conductor antenna 8 = 120 mm
The length of the line of the central conductor antenna 7 ′ = 80 mm,
The distance between the horizontal filament of the central conductor antenna 7 and the horizontal filament of the outer conductor antenna 8 = 30 mm
The distance between the horizontal line of the central conductor antenna 7 ′ and the horizontal line of the outer conductor antenna 8 = 30 mm
The antenna is obtained by printing a conductive paste at a predetermined position on the indoor side of the window glass plate, drying it, and baking it.

  The antenna of the present embodiment has two systems arranged as TV broadcast wave UHF band antennas having a frequency of 470 to 770 MHz, and these two systems receive diversity. As shown in the frequency characteristic diagram of FIG. The reception characteristics of one of the two antennas are indicated by thick lines, and the other antenna is indicated by a thin line. The average reception gain of the two antennas is -7.2 dB and -7.4 dB.

[Example 2]
As shown in FIG. 2, the tips of the horizontal conductors of the outer conductor antenna 8 of the first embodiment are bifurcated in both the upper and lower directions, and the respective tips are positioned outside the horizontal conductors of the central conductor antennas 7 and 7 ′ at positions close to each other. Folded filaments were provided on the feeding points 3 and 3 ′ side.

  The length of each filament of the present Example 2 is the same as that of Example 1 shown in FIG. 1, and the difference is that the tip of the horizontal filament of the outer conductor antenna 8 is branched in both the upper and lower directions, and each tip is further divided. The only difference is that a folded line extending to the feed point 3, 3 ′ side is provided outside the horizontal line of the central conductor antenna 7, 7 ′.

  Further, the central conductors 2a and 2a of the two coaxial cables 2 and 2 are separately connected to the positive feed points 3 and 3 ', respectively, and the outer conductors 2b and 2b' of the two coaxial cables 2 and 2 are summarized. And connected to a feeding point 4 of one negative electrode.

  In this case, the two central conductor antennas 7 and 7 ′ are not only interrupted by the horizontal filament extending from the feeding point 4 of the outer conductor antenna 8, but the folded filaments are the central conductor antennas 7 and 7. Because it is close to the horizontal line of ', the radio waves of the center conductor antennas 7 and 7' are likely to flow toward the folded line side of the outer conductor antenna 8, and the center conductor antennas 7 and 7 'may adversely affect each other. Absent.

[Example 3]
As shown in FIG. 3, the tips of the horizontal conductors of the outer conductor antenna 8 of the first embodiment are bifurcated in both the upper and lower directions, and further, the tips of the outer conductor conductors 8 are located inside the horizontal conductors of the central conductor antennas 7 and 7 ′. Folded filaments were provided on the feeding points 3 and 3 ′ side.

  The length of each filament of the third embodiment is the same as that of the first embodiment shown in FIG. 1, and the difference is that the tip of the horizontal filament of the outer conductor antenna 8 is branched in both the upper and lower directions. The only difference is that a folded line is provided inside the horizontal line of the central conductor antenna 7, 7 '.

  Further, the central conductors 2a and 2a of the two coaxial cables 2 and 2 are separately connected to the positive feed points 3 and 3 ', respectively, and the outer conductors 2b and 2b' of the two coaxial cables 2 and 2 are summarized. And connected to a feeding point 4 of one negative electrode.

  In this case, as described in the second embodiment, the two central conductor antennas 7 and 7 ′ are not only blocked by the horizontal line extending from the feeding point 4 of the outer conductor antenna 8, but Since each folded line is close to the horizontal line of the center conductor antennas 7 and 7 ′, radio waves from the center conductor antennas 7 and 7 ′ easily flow to the folded line side of the outer conductor antenna 8. , 7 'does not cause a decrease in sensitivity.

[Example 4]
As shown in FIG. 4, the outer skin conductor antenna 8 of Example 1 was made into a closed-loop rectangular shape, and the rectangular outer skin conductor antenna 8 was sandwiched between two systems of central conductor wires 7, 7 ′.

  Further, the central conductors 2a and 2a of the two coaxial cables 2 and 2 are separately connected to the positive feed points 3 and 3 ', respectively, and the outer conductors 2b and 2b' of the two coaxial cables 2 and 2 are summarized. And connected to a feeding point 4 of one negative electrode.

  The length of the central conductor antenna of the fourth embodiment is the same as that of the first embodiment shown in FIG. 1, and the only difference is that the outer conductor antenna 8 is a closed loop rectangular shape. The vertical dimension of the rectangular portion is 40 mm, the horizontal filament is 110 mm, and the horizontal filament extending from the feeding point 4 to the closed loop rectangle is 10 mm.

[Example 5]
As shown in FIG. 5, the ends of the horizontal filaments extending from the feeding point 4 are branched and bent in both the upper and lower directions, and further, the filaments are provided with the tips folded back toward the respective feeding points. , 7 'and the feeding point 3, 3' surrounding the positive electrode are extended and connected to the negative feeding point 4, and the outer conductor antenna 8 is formed in an 8-shaped loop shape.

  Further, the central conductors 2a and 2a of the two coaxial cables 2 and 2 are separately connected to the positive feed points 3 and 3 ', respectively, and the outer conductors 2b and 2b' of the two coaxial cables 2 and 2 are summarized. And connected to a feeding point 4 of one negative electrode.

  The length and interval of each filament in Example 5 are as follows.

  The length of the strips of the central conductor antennas 7 and 7 ′ and the distance between the horizontal strip of the central conductor antennas 7 and 7 ′ and the horizontal strip extended from the feeding point 4 of the outer conductor antenna 8 are the same as those in the first embodiment.

  For the outer conductor antenna 8, the length of the line from the feeding point 4 to the starting point is 120 mm, and the lengths of the vertical and horizontal sides of the rectangular loop line-shaped portion are 120 mm and 150 mm, respectively. did.

  As in the antenna of the first embodiment, the antenna of the fifth embodiment is arranged as two antennas in the TV broadcast wave UHF band having a frequency of 470 to 770 MHz. As a result of diversity reception of these two systems, the frequency shown in FIG. As shown in the characteristic diagram, when the reception characteristics of one of the two antennas are indicated by bold lines and the other antenna is indicated by a thin line, the average reception gain of the two antennas is −8.1 dB, −7.6 dB, Although the receiving sensitivity is slightly lower than that of the first embodiment, it is almost at a practical level.

[Comparative Example 1]
A comparative example 1 shown in FIG. 6 is a conventional two-system ungrounded antenna pattern and its feeding point. Each system has a positive electrode that connects the central conductor of the coaxial cable and a negative electrode that connects the outer conductor. Each feeding point is made into one system, and extends from each of the feeding points, and includes at least an antenna wire having a horizontal wire.

  As shown in the figure, the feed points are arranged in the order of the negative pole and positive pole for the first system antenna, the positive pole and negative pole for the second system antenna, and the antenna connected to the positive pole of the first system. And the antenna connected to the positive electrode of the second system are adjacent to each other, and the antennas connected to the two negative electrodes are arranged outside the positive antenna.

  The length of the central conductor and the length of the outer conductor of each of the two systems of antennas of Comparative Example 1 are the same as the length of the central conductor and the outer conductor of Example 1, and a TV broadcast with a frequency of 470 to 770 MHz. As a result of diversity reception of these two antennas as a wave UHF band antenna, as shown in the frequency characteristic diagram of FIG. 12, the reception characteristics of one of the two antennas are indicated by bold lines, and the other antenna is indicated by a thin line. As shown, the average of the reception gains of the two antennas is −9.3 dB and −9.7 dB, which indicates that the reception sensitivity is 2 to 3 dB lower than that of the first embodiment.

  Furthermore, since the pattern of the comparative example 1 increases the total number of feeding points and antenna wires, the occupied area of the entire antenna becomes a large area.

[Comparative Example 2]
In Comparative Example 2 shown in FIG. 7, similarly to Comparative Example 1, non-grounded antenna terminals are divided into two equal parts, a total of four terminals, and antenna wires are arranged from each feeding point. Yes.

  As shown in FIG. 7, the arrangement of the feeding points is the order of the positive and negative electrodes for the first system antenna, the positive and negative electrodes for the second system antenna, and the antenna connected to the first system positive electrode. And, the negative antenna line of the first system extends between the antennas connected to the positive electrode of the second system, and the two negative antenna lines extend just between the two positive antennas. Therefore, the two positive antennas do not adversely affect each other, but the total number of feeding points and antenna wires increases, and the occupied area of the entire antenna becomes large.

[Comparative Example 3]
In Comparative Example 3 shown in FIG. 8, similarly to Comparative Example 2, four terminals for non-grounded antennas are arranged in two equal parts, and a total of four terminals are arranged from each feeding point. Yes.

  As shown in FIG. 8, the arrangement of the feeding points is the order of the positive electrode and negative electrode for the first system antenna, the negative electrode and the positive electrode for the second system antenna, and the antenna connected to the positive electrode of the first system. And the negative antenna line of the first system and the negative antenna line of the second system extend between the antennas connected to the positive electrode of the second system, and the two negative antennas are just between the two negative antennas. Since the antenna line extends so as to cut off, the two positive antennas do not adversely affect each other, but the feeding area and the total number of antenna lines increase, so the total area occupied by the antenna is large. End up.

  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. The figure which shows Example 3 of the glass antenna of this invention. 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 figure which shows the antenna pattern of the comparative example 1. The figure which shows the antenna pattern of the comparative example 2. The figure which shows the antenna pattern of the comparative example 3. The whole figure which provided the glass antenna of the present invention in the window glass of a car. FIG. 3 is a frequency characteristic diagram of Example 1 of the present invention. The frequency characteristic figure of Example 5 of this invention. FIG. 6 is a frequency characteristic diagram of Comparative Example 1.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Window glass 2 Coaxial cable 2a Center conductor 2b Outer conductor 3, 3 'Positive electrode feeding point
4, 4 'Negative feed point 7, 7' Center conductor antenna 8, 8 'Skin conductor antenna 10 Window frame 11 Defogger 12 Radio antenna

Claims (4)

  In a glass antenna for a vehicle that receives two antennas of non-grounding type with conductive wires extending from each feeding point of the positive electrode and the negative electrode on the same glass surface and receives the two antennas with diversity, One negative feed point and two positive feed points in the vicinity of both sides thereof, the outer conductor antenna extending from the negative feed point, and a central conductor antenna from each of the two positive feed points, A glass antenna for a vehicle, wherein the internal conductors of two coaxial cables are connected to two positive feed points, respectively, and the two external conductors are connected to a negative feed point.   The said outer conductor antenna has at least a horizontal filament, and its length is set to 1 / 4αλ to 3 / 4αλ (α: wavelength reduction rate of glass plate, λ: wavelength of received radio wave). The glass antenna for vehicles according to 1.   3. The vehicle according to claim 2, wherein the two central conductor antennas are provided at least on the upper and lower sides of the horizontal conductor of the outer conductor antenna and have at least two horizontal conductors extending from each of the two positive electrode feeding points. Glass antenna.   The vehicle according to any one of claims 1 to 3, wherein the length of the two central conductor antennas is set to 1 / 4αλ to 3 / 4αλ (α: wavelength shortening rate, λ: wavelength of received radio wave). Glass antenna.

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