JPH04332203A - Mobile antenna - Google Patents

Abstract

PURPOSE:To provide a highly sensitive, wide band, and stable mobile antenna without obstructing the field of view of a driver or crew. CONSTITUTION:Feeding section 14 is installed on the back of a back miller 1 inside of a car so that feeding section 14 and a feeder 11 are out of the field of view of a driver or crew. Next, fine line is used for antenna elements 6, 9, and 10 that are extended from the feeding section 14 so as not to obstruct the field of view of the driver or crew. Here, by extending antenna elements from the position of the back mirror 1, these antenna elements are separated from metallic section of a window, thereby being able to improve the sensitivity of the antenna, and further the use of three antenna elements enables the antenna to cover a wide band. Furthermore, the feeder 11 and feeding section 14 are provided with balun 12 to protect the sensitivity characteristic of the antenna from becoming unstable by pulling around the feeder 11 or the like.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention is installed inside a moving body having a rearview mirror inside the vehicle body, and is used for television broadcasting and
The present invention relates to a mobile antenna used as an antenna for receiving M broadcasting, etc., or as a transmitting/receiving antenna for communication.

0002

2. Description of the Related Art With the recent shift to a car-based lifestyle and the widespread use of liquid crystal television receivers, there has been an increasing demand for watching television inside the car. In this case, a vehicle-mounted antenna is required to receive television radio waves, and conventionally, a roof side antenna mounted on the roof side outside the vehicle has generally been used.

However, there are some car models that cannot be attached to roof side antennas due to car design reasons, and they may fall off while driving, cause noise from the wind, be damaged when washed or parked in a garage, or cause damage to power lines. There is a strong demand for an antenna that can be installed inside a car due to problems such as the complexity of installation, theft, and deterioration of the aesthetic appearance. For this reason, various antennas that can be installed inside a vehicle have been proposed.

FIGS. 11(a), (b), and (c) show a first conventional example, which is based on the patent application filed in 1986 by the present applicant.
3-824 is a configuration diagram of a wideband mobile antenna based on the technology disclosed in No. 3-824. In this conventional example, two high channel antenna elements 101 and 102 and a low channel antenna element 103 are connected to a feed line 105 made of a coaxial cable in a feed box 104 as shown in FIG. 11(b). A balloon 1 is placed at a feeding point 1/2 wavelength from the tip of the antenna element 103 on the feeding line 105.
06 is provided, and a plug 107 for connecting to a television receiver is attached to the end of a power supply line 105. The balun 106 is a high impedance common mode filter also called a balun, and is a type of balanced/unbalanced converter.As shown in FIG. 11(c), a coaxial cable 106b is connected to a short cylindrical ferrite ring 106a.
It is formed by being rolled.

FIGS. 12(a), 12(b), 12(c), and 12(d) show specific examples of shapes of the first conventional example.
(b) is the antenna element 101 (or 102, 1) described above.
03) (However, (a) is for the front window frame, (b)
) is a sectional view of (b), and (d) is an exploded perspective view showing the assembly of the feed box 104 portion described above. Each antenna element 101 (or 102, 103) is formed by joining two copper foils 101a, 101b with a width of 0.4 to 0.5 mm at ends 101c, 101d. These copper foils 101a, 101b and end portions 101c, 101d are coated with adhesive directly on their back surfaces in FIG.
After being covered with the insulator 101e as shown in (c) (however, a part of the surface of the end portion 101c is exposed),
Adhesive 101f is applied to the back surface. Each antenna element 101, 102, 103 is placed in the feed box 104 at its end 101c as shown in FIG. 12(d).
is positioned in the lower case 104a, and screw 1 is inserted from above.
As the wiring board 104c is pressed at 04b, as shown in FIG.
1(b), it is wired to the feeder line 105 of the coaxial cable. 104d is a protective cover fitted to the lower case 104a.

FIG. 13 is a diagram showing an example of mounting the first embodiment configured as described above, and shows a passenger car 110 viewed from above. The antenna of this example is
1 on the front window frame 110a or the rear window frame 110b.
The antenna elements 101, 102, and 103 shown in 2 are attached to the inside of the vehicle by pasting them with adhesive applied to their back surfaces. In this case, on the front window frame 110a side, the antenna elements 101 and 102 are installed horizontally in the vicinity of 10 cm above, and the antenna element 103 is installed approximately in the center in the vertical direction. On the other hand, on the rear window frame 110b side, the antenna elements 101, 102, 103 are 90
It can also be attached and attached at an angle smaller than °. In either case, the feed box 104 which is the power supply unit
is arranged above the window frame, and the feeder line 1 including the balun 106
05 is placed along the window.

In the first conventional example configured and installed as described above, the balun 106 has one end of the feed point equivalently grounded so that the antenna wire can be installed without being grounded to a metal part of the vehicle body, etc. A part of the feeder line 105 can be used as part of the low channel antenna element, achieving high sensitivity while reducing the area occupied by the antenna in the window. Note that the heater wire 110c is provided inside the rear window frame 110b, but the insulator 101e covering the copper foils 101a, 101b, etc. shown in FIG. 12(c)
This prevents the heater wire 110c from shorting.

Next, a second conventional example is shown in the perspective view of FIG. The antenna 121 of this conventional example has an antenna arm 1
21a and an antenna element 121b, and the antenna arm 121a has a five-stage click mechanism using a parallel crank. One end of this antenna arm 121a is
The antenna 121 is fixed to an arm 123a of a rearview mirror 123 inside a front window frame 122, and is arranged along the windshield. The antenna element 121b is attached to the other end of the antenna arm 121a, and even when the antenna arm 121a is manually rotated in five steps, it is bent into an L-shape and always maintained in a horizontal state. In this conventional example,
This five-stage rotational adjustment creates a two-frequency configuration, which allows a single antenna to provide a wide band.

Next, a third conventional example is shown in FIGS. 15(a) and 15(b).
) is shown in the configuration diagram. This conventional example is based on Utility Model Application Publication No. 1-1153.
This is disclosed in Publication No. 10. In this conventional example,
The antenna 130 is formed by patterning it into a band-shaped film, and is used by adhering it to the edge of the windshield 131a of an automobile 131 from the inside, as shown in FIG. 3(b).

Next, a fourth conventional example is shown in FIG. 16, a fifth conventional example is shown in FIG. 17, and a sixth conventional example is shown in FIG. 18. In all of these, part or all of the antenna 140 is attached to the glass surface near the window frame using an adhesive. In addition to the above, examples are also known in which antenna elements are embedded inside window glass.

[0011]

[Problems to be Solved by the Invention] However, the above-mentioned conventional mobile antennas installed in a vehicle have the following problems.

(1) In the first conventional example shown in FIGS. 11 to 13, although sufficient sensitivity can be obtained, the antenna element 10
1 (or 102, 103) ends 101c, 101d
Since the antenna is thick and the feed box, which is the power feeding part, is located above the window frame, there are rules for installing the antenna on the glass in the window frame (e.g., do not obstruct the driver's view, the printed line should be 0.5 mm). (e.g., the following). Furthermore, since the antenna elements 101, 102, and 103 are thin and therefore have weak adhesive strength, there is a risk that they may peel off or break when cleaning windows or the like.

(2) In the second conventional example shown in FIG.
Since the antenna arm 121a and the antenna element 121b are thick, and the mounting portion for fixing to the arm 123a of the rearview mirror is naturally large, there is a problem that the driver's view is obstructed or the driver feels dazzled. Further, although the antenna 121 has a two-frequency configuration, complete compatibility cannot be obtained, and the sensitivity is not so good.

(3) The third prior art band-shaped film antenna 130 shown in FIG. 15 has a considerable film width, so no matter where it is attached to the window glass, the field of view is narrowed and the driver's It obstructs the view, gets in the way, and spoils the aesthetics. For this reason, the antenna element must be attached to the edge of the window glass, and the antenna element approaches the metal body near the window, resulting in steeper frequency characteristics due to the shielding effect and increased distributed capacitance, and at the same time, sensitivity decreases due to impedance mismatch. In particular, in the low channel, the width of the window is narrower than the wavelength, so sufficient sensitivity to radio waves arriving from the front cannot be obtained.

(4) Fourth to sixth shown in FIGS. 16 to 18
In each of the above embodiments, the visibility is obstructed by the antenna element 140 or the attachment part and the feeding part, and at the same time, the above (
For the same reason as in 3), even when compared to 1/2 wavelength antennas, the sensitivity of most low channels is as low as −10 dB or less.

(5) In an example in which the antenna element is embedded inside the window glass, a sufficiently thin 0.5mm antenna element is used as the antenna element.
A metal wire of 25 mm or less can be used and does not obstruct visibility. However, the sensitivity is insufficient.

As described above, there is no conventional mobile antenna that does not obstruct the field of view and has sufficient sensitivity. The present invention was made to solve these problems, and its purpose is to provide a mobile antenna that does not obstruct the driver's or passenger's view and has high sensitivity and wide band characteristics. It is about providing.

[0018]

[Means for Solving the Problems] In order to achieve the above object, the mobile antenna of the present invention includes a power feeding section provided on the back side of a rearview mirror installed inside the moving object, and a thin wire extending from the power feeding section. It is characterized by having an extending antenna element and a high impedance element provided at a feeding point to block common mode signal current.

[0019]

[Operation] In the mobile antenna of the present invention, the power feeding portion is provided on the back side of the rearview mirror inside the vehicle, so that the power feeding portion and the power feeding line are kept out of sight. In addition, by extending the antenna element from this feeding part with a thin wire, the antenna element does not obstruct the view, and
Sensitivity is improved by placing it away from the metal parts near the window. on the other hand,
By providing a high impedance element at the feeding point of the feeder line, the effects of the routing of the feeder line are eliminated and the characteristics are stabilized.

[0020]

Embodiments Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a perspective view showing the structure of a first embodiment of the present invention, and shows a view looking toward the front window frame from inside the vehicle. 1 in the figure as the members constituting this embodiment.
is the rearview mirror, 2 is the arm of the rearview mirror, 3 is its mounting part, 4 is the ceiling, 5 is the dashboard, 6 is the antenna element for the low channel, a piano wire with a black surface treatment,
Reference numeral 7 is a telescopic spring that is part of the antenna element 6, and reference numeral 8 is an insulator that is fixed to the dashboard 5. Reference numerals 9 and 10 denote left and right antenna elements for the high channel, which are made of piano wire similar to the antenna element 6 for the low channel and have a structure that can be bent to stand on their own, and are fed in parallel so that the band can be widened. Reference numeral 11 is a power supply line from the rear of the rearview mirror 1 and is attached to the rearview mirror arm 2 and next to the upper window. 12 is a coaxial balun with 1.7C
It consists of a -2V coaxial cable wrapped around a ferrite ring around 5.5 turns. The feeder line 11 up to this balun 12 forms part of the antenna. Reference numeral 13 denotes a power supply line made up of a similar coaxial cable and is connected to the receiver. Reference numeral 14 denotes a power feeding section provided at the rear (back surface) of the rearview mirror 1, where the respective antenna elements 6, 9, and 10 are connected to the feeding line 11 in the same manner as shown in FIG. 11(b).

FIGS. 2(a) and 2(b) show the rearview mirror 1.
It is a block diagram of the power supply part 14 attached to the rear part of (a)
(b) is a view of the rearview mirror 1 seen from the back, and (b) is a view of it from below. The power supply unit 14 is a printed circuit board 14
a, the base 6a of each antenna element 6, 9, 10,
It supports the mirrors 9a and 10a and supplies power to them, and is attached to the rearview mirror 1 with a support or holder 14b. 11
a is the outer conductor of the feeder line 11 of the coaxial cable and the board 14a
It is connected to the antenna element 9 on the left side through the fixing screw 14c and the base 9a. 11b
is the core wire part of the power supply line 11, which also has fixing screws 14d,
It is connected to the right antenna element 10 through the base 10a. The fixing screws 14c and 14d also serve as axes for providing flexibility in the mounting angle of the antenna element and in moving the mirror. The base portions 9a and 10a also serve as metal support plates for keeping the widths of the antenna elements 9 and 10 constant. The base portion 6a is configured to serve both as a loading coil and a spring for the low channel antenna element 6.

FIG. 3 is a block diagram showing the structure of a second embodiment of the present invention. This embodiment has the same antenna configuration as the first embodiment, but the high channel antenna element 9
, 10 are thin, so in order to compensate for their independence, the tips of each of the antenna elements 9 and 10 are pulled by a spring 16 from a set screw 17 of the sun visor via an insulator 15. The configuration other than the above is the same as that of the first embodiment.

Examples of shapes of each antenna element and holder in the second embodiment are shown in FIGS. 4(a) and 4(b). (a)
(b) shows a specific configuration diagram of the high channel antenna elements 9, 10 and their holders, and (b) shows a specific configuration diagram of the low channel antenna elements 6 and their holders. In (a), the antenna 9 (or 10) is constructed by fixing one end of a piano wire with a black surface treatment to one end of a metal support plate (base) 9a (or 10a), and folding it back with an insulator 15. , and is formed by being fixed to the other end of the metal support plate 9a (or 10a). On the other hand, the holder has one end of the spring 16 formed into a ring shape and hooked onto the insulator 15, and the other end formed into a ring shape for fixing with a screw. Further, (b) shows an example different from those shown in FIGS. 1 and 3, in which the antenna element 6 is separated by a holding spring 7' and an insulator 15' similarly to (a).

Next, a third embodiment of the present invention will be described. Figure 5
1 is a diagram showing the configuration of this embodiment as viewed from the rear of a rearview mirror 1. FIG. In this embodiment, a balun 18 is provided in the power supply section 14 arranged at the rear of the rearview mirror 1.
The coaxial feed line 11 is coupled to the antenna elements 9, 10 and the antenna element 6 through the antenna element 9, and furthermore, on the base side of the antenna element 9, one end of a single wire 19, which is an element on the ground side of the low channel, is connected. Balun 18 has a ferrite core with two holes and a characteristic impedance of 1.
It is formed by winding parallel wires of 50Ω, and one side is a coaxial feeder line 1.
One outer conductor is connected to the antenna element 9 and the single wire 19, and the other is connected to the core wire part of the feeder line 11 and the antenna elements 6, 10.
Connect. The configuration and arrangement of each antenna element 6, 9, 10 are the same as in the first and second embodiments. In this embodiment, the most sensitive mobile antenna is realized by arranging the ground side element 19 of the low channel from the arm of the rearview mirror 1 to the window and grounding it to the vehicle body.

Next, a fourth embodiment of the present invention will be described. Figure 6
(a) and (b) show configuration diagrams of this embodiment, in which (a) is a view seen from the rear of the rearview mirror 1, and (b) is a view seen from the bottom thereof. This embodiment adds a wideband UHF antenna element to the first or second embodiment described above. Rearview mirror 1 is an element that supports UHF.
The entire structure is a kind of ground, and the UHF antenna element 20 is erected on this ground. However, rearview mirror 1
Metal foil 2 because it cannot be directly connected to the internal metal.
1 is bonded to the rear surface of the rearview mirror 1 for capacitive coupling, and this is connected through a part 22 of the substrate 14a to have the same potential as the base of the high channel antenna element 9. Further, the UHF antenna element 20 is fixed with a metal fitting 23 at the antenna base, and at the same time is rotatable to some extent at an angle as shown in (b), and is connected so as to have the same potential as the base of the high channel antenna element 10. ing. The reason why the UHF antenna element 20 is made movable is as follows.
This is to change the directivity by changing the direction, and to prevent force from being applied to the element when it comes into contact with the windshield.

The operation and effect of each embodiment configured as above will be described.

In each of the above embodiments, the following measures (1) to (5) are taken to prevent the installation of the antenna from interfering with the driver's or passenger's view. (1) A thin wire as an antenna element, i.e. a thin wire with a diameter of 0 that can maintain strength and shape.
．． Piano wire of 2 to 0.25 mm was used. (2) The surface of the piano wire was matte black to absorb light and make it less noticeable. (3) The antenna element is placed vertically at the top, where it is difficult to see the driver, and at the center, albeit boldly. This is because it has been found that drivers are concerned about the left and right sides of the window when checking left and right at intersections, but rather the center area is relatively less of a concern. (4) Place the power supply unit on the back of the rearview mirror,
The power supply line was placed along the arm of the rearview mirror and the window. (5) The back side of the rearview mirror was also used when adding a UHF antenna element.

Furthermore, in each of the above embodiments, the following (a) and (
By taking measures (b) and (c), the antenna has high sensitivity and a wide band. In order to obtain a highly sensitive and wideband antenna, there are certain positions and directions for the antenna that can easily couple with the external space. Here, it is assumed that the television broadcast is horizontally polarized. In addition, FIG. 7 is a layout diagram of an antenna inside a car that can obtain high sensitivity when there are no restrictions. 1 indicates the rearview mirror, 110 indicates the vehicle body, and (a) shows the antenna element with the highest sensitivity for the high channel. Position, (b) shows the most sensitive position of the low channel antenna element. (b) A power feeding section is placed on the back of the rearview mirror, and a high channel or UHF band antenna element extending from there is placed horizontally close to the glass surface, and placed 10 to 20 cm below the top of the glass surface. . This prevents the antenna element from getting too close to the metal body near the window and lowering the sensitivity due to the shielding effect and increase in distributed capacitance, and makes it possible to maximize the sensitivity to radio waves coming from the front. In other words, it can be brought closest to the position shown in FIG. 7(a). (b) The rearview mirror is used as the feeder, and the low channel antenna element is extended from this to the center of the window, while a balun is provided on the feeder line and becomes part of the antenna element from the feeder point to that point. The antenna position and direction that provides the highest sensitivity in the low channel are shown in Figure 7 (b).
This is the case when the radio waves arrive from the side. Therefore, providing a power feeding part in the rearview mirror and providing one antenna element in the center approximates the situation shown in FIG. 7(b), and also
In b), one antenna element is placed on the ceiling, but this is difficult in practice, so in this example, as described above, one antenna element is placed along the boundary between the window glass and the metal car body, and the same condition is achieved. , high sensitivity has been obtained. (c) The high channel antenna element was bent into two pieces and used in parallel. Since the low channel is 18 MHz, it can be covered with one antenna element (within -1 dB), but the high channel is wide at 54 MHz, so the above-mentioned two antenna elements are used in parallel to widen the band (within -1 bB).

Next, even if the antenna has high sensitivity and a wide band, it needs to be stable so that the sensitivity of the antenna does not change due to the routing of the feeding section, etc. In the above embodiment, the balun contributes to its stabilization. Here, the action of the balun will be explained using the antenna configurations shown in FIGS. 8(a), (b), (c), (d), and (e).

In FIG. 8, (a) and (d) are 1/
It has a configuration in which a balloon BU is attached directly to the feeding part of the two-wavelength dipole antenna elements AE1, AE2 or AE3, AE4, and (a) corresponds to the high channel, and (b) corresponds to the low channel. Here, the balun BU blocks unnecessary current (common mode current) carried by the outer conductor of the coaxial power supply line W to prevent its influence.

FIG. 8(b) shows a configuration in which the position of the balun BU is moved from the feeding section S of the dipole antenna elements AE1 and AE2 to a position on the feeding line W of 1/2 wavelength of the wavelength λH of the high channel. . In the figure, I1 and I2 indicate wave current distributions of wavelength λH, I1 indicates normal mode current distribution, and I2 indicates common mode current distribution. In this case as well, as a result of the common mode current being blocked by the balloon BU, as can be seen from the current distribution I2 flowing in the outer conductor of the feeder line W, unnecessary components enter the coaxial line from the feeder S of the antenna and disturb the impedance. There is nothing to do.

In FIG. 8(c), a monopole antenna element AE3 having a wavelength of 1/4 of the wavelength λL of the low channel is attached in place of the high channel antenna elements AE1 and AE2 of FIG. 8(b). Since the frequency ratio of the low channel and high channel of Japanese television broadcasting is 1:2, the distance from the tip of the antenna element AE3 to the balun BU is 1/2 wavelength of the low channel wavelength λL. becomes. Here, since the high frequency current riding on the outer conductor of the feed line W from the feed section S to the balun BU is cut by the balun BU, the current distribution I3 from the tip of the antenna element AE3 to the balun BU is as shown by the broken line in the figure. The antinode of the wave appears in part S. That is, the outer conductor of the feeder line W functions as one of the low channel antenna elements, thereby realizing a low channel antenna.

FIG. 8(e) shows the antenna for the high channel shown in FIG. 8(b) and the antenna for the low channel shown in FIG. 8(c) integrated to form a two-frequency wide band. This corresponds to the first to third embodiments. Here, the high channel antenna elements AE1 and AE2 and the low channel antenna element AE3 are configured to be orthogonal to each other. As mentioned above, the action of the balun BU prevents unnecessary components from entering the feed point S and disturbing the impedance, so the outer conductor of the feed line W between the balun BU and the feed section S is connected to the low channel. It can be used as part of an antenna element. That is, the antennas of FIG. 8(b) and FIG. 8(c) can be integrated, and a dual-frequency wideband antenna can be realized.

[0035]Although the embodiment shows an antenna configuration based on the antenna configuration shown in FIG. It is conceivable that the configuration may be combined or modified as needed based on the basic configuration. FIG. 9 shows an example of its application and modification, and shows a schematic diagram of the antenna and the feeder line when looking in front of the window from inside the car, and the broken line shows the boundary between the upper part of the window and the metal car body. A and B in (a) are shown in Figure 8 (a)
, (b) is the basic configuration of the high channel. In (a), one antenna element AE2 is placed along the arm of the rearview mirror so that the antenna element does not enter the driver's field of vision.
Furthermore, it is configured so that it is placed next to the window on the right side and grounded to the vehicle body. This takes advantage of the fact that the high channel frequency is equivalent to the ground. In (c), one antenna element of the low channel is placed from the arm of the rearview mirror to the window and grounded to the vehicle body. This is the configuration with the best sensitivity, and B corresponds to the first to third embodiments, and A corresponds to the fourth embodiment. (d) is (
Right high channel antenna element AE in c)
2 is also configured to match the metal of the car body. (E) is a configuration excluding the lower antenna element AE3 of the low channel, but the antenna element AE4 for the low channel on the ground side
Because it is attached, it interacts with the high channel antenna element on the left, and as shown in the graph below, a certain degree of sensitivity can be obtained in the low channel as well. Although the above explanation has been made only regarding the low channel and high channel, it goes without saying that there is sensitivity even in the UHF band.

An example of measuring the sensitivity of the typical antenna described above is shown in the graph of FIG. In the figure, the horizontal axis indicates the channel number of Japanese television broadcasting, and the maximum vertical axis indicates the maximum output voltage of 0 dB obtained when a 1/2 wavelength dipole antenna is placed approximately 1.5 m above the ground. This is the maximum output voltage ratio obtained with the antenna of the present invention obtained by placing and rotating 360°. Sensitivity curve (1), (2
) and (3) correspond to B in FIG. 1 or 2 and (c) in FIG. (4) is the sensitivity characteristic in the case of FIG. 6 in which a UHF antenna is further added. (5) is shown in Figure 9.
In case A of (e), the sensitivity of the low channel is reduced, but the configuration is simplified because the long central low channel antenna element is not required. (6) and (7) are the sensitivity characteristics of an example of the conventional antenna shown for reference, and are shown in Figure 17.
This is the case for the antenna.

[0037]

Effects of the Invention As is clear from the above description, according to the mobile antenna of the present invention, the feeding section is hidden behind the rearview mirror and out of sight, and the antenna element extending from there is provided with a thin wire. Because it is used, it can be used so that it does not obstruct the view. Also, since it is not glued to the window glass, there is no need to worry about it being damaged by window cleaning, etc. Furthermore, since the antenna element can be placed a certain distance from the window, it is possible to achieve high sensitivity and a wide band, and the sensitivity characteristics can be stabilized by using a high impedance element.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing a first embodiment of the present invention.

[Figure 2] (
a) and (b) are configuration diagrams of the power feeding section of the above first embodiment.

FIG. 3 is a configuration diagram showing a second embodiment of the present invention.

[Figure 4] (
a) and (b) are diagrams showing examples of the shapes of the antenna element and the holder of the second embodiment.

FIG. 5 is a configuration diagram showing a third embodiment of the present invention.

[Figure 6] (
a) and (b) are configuration diagrams showing a fourth embodiment of the present invention.

[Figure 7] In-vehicle layout of antenna that provides high sensitivity

[Figure 8
] (a), (b), (c), (d), and (e) are diagrams for explaining the action of the balun.

[Fig. 9] A diagram showing an example of application and modification of the antenna of the present invention.

[
Figure 10: Graph showing measurement examples of the antenna of the present invention

[Figure 1
1] (a), (b), and (c) are configuration diagrams showing the first conventional example

[Figure 12] (a), (b), (c), and (d) are the first
A diagram showing a specific example of the shape of a conventional example.

FIG. 13 is a diagram showing an example of mounting the first conventional example.

[Figure 14
] A perspective view showing a second conventional example

[Fig. 15] (a) and (b) are configuration diagrams showing the third conventional example.

FIG. 16 is a configuration diagram showing a fourth conventional example

[Fig. 17] Configuration diagram showing the fifth conventional example

[Fig. 18] Configuration diagram showing the sixth conventional example

[Explanation of symbols]

1...Rearview mirror, 2...Rearview mirror arm, 6...Low channel antenna element, 9, 10...High channel antenna element, 11, 13...Feed line, 12...Balun, 1
4...Power supply section.

Claims (3)

[Claims] Claim 1: A power feeding part provided on the back surface of a rearview mirror installed in a moving body, an antenna element extending from the power feeding part by a thin wire, and a high voltage antenna element provided at the feeding point to block common mode signal current. A mobile antenna comprising an impedance element. 2. A power feeding part provided on the back surface of a rearview mirror installed in a moving object, a monopole antenna element extending from the power feeding part by a thin wire, and approximately 1/2 from the tip of the monopole antenna element. 1. A mobile antenna comprising: a high impedance element that is provided at a feed line position based on wavelength and blocks common mode signal current. 3. A power feeding part provided on the back surface of a rearview mirror installed in a moving body, a dipole antenna element extending from the power feeding part by a thin wire, and a distance of approximately 1/2 wavelength from the tip of the dipole antenna element. 1. A mobile antenna comprising: a high impedance element provided at a basic feed line position to block a common mode signal current.