JPH09307334A - Earth structure for antenna and on-vehicle antenna system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To ensure proper reception sensitivity by configuring a diversity antenna system with three loop antennas of longitudinally long rectangle, laterally long rectangle and circle shape and selecting the relation of lateral and longitudinal length so as to decide the size. SOLUTION: Three antennas 10, 20, 30 are provided on the front side of a window glass toward the interior of a vehicle body to configure the diversity antenna system. The antenna 10 is a reception antenna for FM and TV radio waves and formed to be a longitudinally long looped rectangle. The antenna 20 is shaped to be a laterally long looped rectangle and the antenna 30 is shaped circular. The size of the antenna is selected according to the relations of y<=λ/4.α, 60cm-y>=x (sum of (x) and (y) does not exceed 60cm), where (x) is the lateral length, (y) is the longitudinal length of the three antennas, λ is a wavelength with respect to the operating frequency and α is the glass reduction rate. Thus, the antenna performance where proper reception sensitivity is ensured while securing a visual field is obtained and the antenna system mounted simply is provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle-mounted antenna device equipped with a ground provided on a glass window of a vehicle or the like and a ground structure for the antenna.

[0002]

2. Description of the Related Art Since a vehicle glass window regulates a driver's field of view, various laws and regulations are applied to a glass antenna provided in the window in order to secure the driver's field of view. . Therefore, the size, width, and length of the glass antenna cannot be freely designed, and there are certain restrictions.

Since the glass antenna has a disadvantage in sensitivity as compared with the rod type antenna, the limitation on the shape due to the above-mentioned regulation has a great influence on the antenna performance. Although not particularly conscious of legal regulations, there is a conventional antenna related to a glass antenna whose shape has been devised, for example, a vehicle antenna device of Japanese Patent Publication No. 3-74845 and a loop-shaped glass antenna of Japanese Patent Laid-Open No. 3-1703. In addition, there is a paper “Broadband Omnidirectional Disc Monopole Antenna” (co-authored by Inou Itou and Sekiichi).

In the antenna device for a vehicle of Japanese Patent Publication No. 3-74845, paying attention to the relationship between the metal pillar pillar and the antenna, the pillar length is λ / 2 (λ is the wavelength of the received radio wave) or less, and the antenna length is λ. / 4 or less is set. This prior art,
It basically discloses a monopole antenna because it is interested in the relationship with the pillar, and therefore there is no mention in the width direction, and therefore, in the size of the current vehicle, the FM frequency band is used at most. Only applicable to.

The glass antenna disclosed in Japanese Patent Laid-Open No. 3-1703 has a loop shape having a total length of 200 to 1500 mm, and the conductive wire to the feeding point is set substantially parallel to the longitudinal centerline of the vehicle. Is what you are doing. However, this prior art is also interested in the total length of the loop antenna, but is not interested in the relationship between the length in the vertical direction and the length in the width direction of the antenna. Therefore, in order to satisfy the legal regulations and achieve high reception performance, it is necessary to repeat trial and error in which the vertical and horizontal lengths are variously changed within the range of 200 to 1500 mm.

Further, the disk-shaped monopole antenna shown in the above-mentioned paper is intended for widening the band by a circular disk, and therefore, when this antenna is applied to a glass antenna for a vehicle, the field of view is increased. Interfere. There is a dislike that the target performance cannot be achieved if the size is reduced to secure the visibility. Further, although it is proposed to provide an antenna behind the rear-view mirror position as in Japanese Patent Laid-Open No. 50-24928, there is no suggestion of what size the antenna should be set.

Further, as a conventional example of a vehicle-mounted antenna device, further, Japanese Patent Laid-Open Nos. 61-82502 and 2-2 are available.
There are 72804 and Jitsukaihei 5-82113.

[0008]

By the way, JP-A-61-61
-82502, Japanese Patent Laid-Open No. 2-272804, and Kaikaihei 5
No. 82113 or the like adopts screwing, bonding, or a ground pattern or the like in order to ground the outer sheath wire (shield wire) of the feeder wire of the antenna device. Therefore, it is difficult to retrofit the vehicle with an antenna ground.

On the other hand, Japanese Patent Laid-Open No. 5-152817 proposes that a ground wire be run along an antenna harness for the purpose of preventing a decrease in reception sensitivity. In this prior art, the wire that is soldered to the shield wire of the feeder wire is used as the ground wire, so that the installation of the ground to the vehicle body is unintentionally simplified. However, the grounding structure according to Japanese Patent Laid-Open No. 5-152817 is designed so that the grounding wire is provided along the vehicle harness, that is, it is assumed that the harness is located near the antenna installation portion. It will not be applicable to vehicles that do not have. Further, even in a vehicle provided with a harness, it is not easy for the user to attach the ground to the harness.

Therefore, the present invention has been made in view of the problems of the prior art, and an object thereof is to propose a grounding structure capable of more easily grounding without deteriorating the antenna performance. is there. Another object of the present invention is to propose a grounding structure and a vehicle-mounted antenna device capable of grounding more easily without impairing antenna performance and visibility.

[0011]

In order to achieve the above object, a grounding structure for a feeder wire for transmitting a received signal from an antenna to a receiver or the like according to the present invention has a ground wire of the feeder wire at one end. And a long ground portion having a predetermined length, which is connected to the above. The long ground portion is characterized in that the one end to the other end are not grounded and the other end is open.

When the other end is released, the long ground portion forms a transmission line, and the electric potential becomes substantially zero at the one end, thus substantially functioning as the ground. Therefore, the performance of the antenna equipped with this ground structure is not impaired. Further, since this ground structure has the other end open, it does not need to be fixed and is easily mounted.

According to a preferred aspect of the present invention, the long ground portion can also serve as the shield wire of the feeder wire, which contributes to cost reduction. Further, the shield wire is easily bent, and therefore, the ground structure can be easily attached to a vehicle or the like. According to a preferred aspect of the present invention, the long earth portion is electrically insulated from the conductor along a planar electric conductor. It is thus ensured that the long earth part constitutes the desired transmission line with this conductor.

According to a preferred aspect of the present invention, the long earth portion is set to have a length of λ / 4 with respect to the wavelength λ of the received radio wave. According to a preferred aspect of the present invention, the long earth portion is provided along a predetermined planar electric conductor via a predetermined insulating layer having a line shortening rate δ, and has a length of , Δ · λ / 4 are set. Therefore, the long earth portion forms a transmission line, and the potential becomes substantially zero at the one end.

According to a preferred aspect of the present invention, the earth structure is provided in a vehicle, the earth portion is extended to a window glass of the vehicle, and the line shortening rate of the window glass is α, the earth is formed. The length of the part is set to α · λ / 4. Therefore, the long earth portion forms a transmission line, and the potential becomes substantially zero at the one end.

According to a preferred aspect of the present invention, the long grounding portion is bundled while being insulated from the feeder wire. Therefore, the earth structure is simplified, and the mounting on a vehicle or the like is facilitated. In order to achieve the above object, an antenna structure of the present invention provided at a position surrounding a vehicle verification seal on an upper part of a windshield of a vehicle is a power feeding unit which is provided above the antenna structure and substantially functions as a power feeding point. A frame-shaped antenna wire having a hollow substantially frame shape and extending on the glass so as to surround a car verification seal in the hollow portion, and a reception signal from the frame-shaped antenna wire to a receiver or the like. A feeder wire for transmission and a grounding portion having one end connected to the grounding wire side of the feeder wire and the other end being open, and the maximum lateral length of the frame-type antenna wire. The length x and the maximum length y in the vertical direction are set so as to satisfy y ≦ α · λ / 4 x ≦ 60 cm-y, where α is the line shortening rate of the windshield, and From the top of the field of view of the windshield It is characterized in that the width of the portion located below the predetermined distance is set to 6.6 cm or less.

Such an antenna device can be easily attached to a vehicle or the like by a simple ground structure, and further, the driver's field of view in front can be secured. An antenna device having another configuration of the present invention to achieve the above object has a power feeding portion that substantially functions as a power feeding point, and a hollow substantially circular shape that is connected to the power feeding portion and has an inner diameter of 7 cm or more. , A round hollow antenna wire extended on the glass so as to surround a regular inspection seal in the hollow portion, and a feeder wire for transmitting a reception signal from the round hollow antenna wire to a receiver or the like, A ground portion having one end connected to the ground wire side of the feeder wire and the other end open to the ground, the maximum horizontal length x and the maximum vertical length of the round hollow antenna wire. The length y is set so as to satisfy y ≦ α · λ / 4 x ≦ 60 cm−y, where α is the line shortening rate of the windshield. Such an antenna device can be easily attached to a vehicle or the like by a simple ground structure, and can further secure the driver's field of view in the front.

An antenna device having another structure of the present invention for achieving the above-mentioned object is provided with a power feeding portion provided at an upper side end portion of a windshield of a vehicle, which substantially functions as a power feeding point, and the power feeding portion. Connected, having a hollow, generally rectangular shape,
A rectangular hollow antenna wire extending above the glass, a feeder wire for transmitting a received signal from the rectangular hollow antenna wire to a receiver, etc., and one end connected to the ground wire side of the feeder wire And a ground portion whose other end is open, wherein the maximum horizontal length x and the maximum vertical length y of the rectangular hollow antenna wire are 5 cm ≦ x ≦ 40 cm 3 cm It is characterized in that it is set so as to satisfy ≦ y ≦ 10 cm. Such an antenna device can be easily attached to a vehicle or the like by a simple ground structure, and can further secure the driver's field of view in the front.

An antenna device having another structure of the present invention for achieving the above object has a power feeding portion that substantially functions as a power feeding point and a hollow frame shape that is connected to the power feeding portion. A frame-shaped antenna wire extended on the side glass of the side portion, a feeder wire for transmitting a reception signal from the frame-shaped antenna wire to a receiver and the like, and one end of which is connected to the ground wire side of the feeder wire. And a ground portion whose other end is open, wherein the maximum horizontal length x and the maximum vertical length y of the frame-shaped antenna wire are x ≦ 30 cm 20 cm ≦ y ≦ It is characterized in that it is set so as to satisfy 40 cm x + y ≦ 60 cm. Such an antenna device can be easily attached to a vehicle or the like by a simple ground structure, and further, the driver's field of view can be secured immediately.

An antenna device having another configuration of the present invention for achieving the above object is a vehicle-mounted antenna device provided on a rear window glass at a rear portion of a vehicle provided with a defogger and is substantially powered. A power feeding unit that functions as a point, a frame-shaped antenna wire that is connected to the power feeding unit, has a hollow frame shape, and extends on the windshield, and a receiver for receiving signals from the frame-shaped antenna wire. And a feeder wire for transmitting the same to a ground wire portion of which one end is connected to the ground wire side of the feeder wire, and the other end of which is open, and the ground portion of the defogger in the vehicle width direction. The vertical maximum length x of the frame-shaped antenna wire and the maximum vertical length y of the frame-shaped antenna wire are the line shortening rates of the antenna wire and the vertical conductor. Is ω, x ≦ 30cm, 20c It is characterized in that m ≦ y + ωL ≦ 40 cm and x + y + ωL ≦ 60 cm. Such an antenna device can be easily attached to a vehicle or the like by a simple ground structure, and can further secure the driver's field of view in the rear.

An in-vehicle antenna device of the present invention having another structure has a power feeding portion substantially functioning as a power feeding point, and a hollow substantially circular shape connected to the power feeding portion and having an inner diameter of 7 cm or more. A round hollow antenna wire extended on the glass so as to surround a regular inspection seal in the hollow portion, a feeder wire for transmitting a reception signal from the round hollow antenna wire to a receiver, and the feeder. And a grounding part having one end connected to the grounding wire side and the other end being open, wherein the maximum horizontal length x and the maximum vertical length y of the round hollow antenna wire are the windshield. When the line shortening rate is set to α, 7 cm ≦ x ≦ 30 cm and y ≦ α · λ / 4 7 cm ≦ y ≦ 10 cm x + y ≦ 60 cm are set. It is particularly suitable for receiving TV radio waves.

An in-vehicle antenna device of the present invention having another structure is a power feeding portion that substantially functions as a power feeding point, has a hollow substantially rectangular shape connected to the power feeding portion, and has an upper portion on the glass. A rectangular hollow antenna wire extended to, a feeder wire for transmitting a received signal from the rectangular hollow antenna wire to a receiver, etc., one end is connected to the ground wire side of the feeder wire, the other end is With an open earth part,
The maximum horizontal length x and the maximum vertical length y of the rectangular hollow antenna wire are set as follows: x ≧ 30 cm, y ≦ α · λ / 4 7 cm ≦ y ≦ 10 cm x + y ≦ 60 cm To do. It is particularly suitable for receiving VICS radio waves.

In order to achieve the above object, the earth structure of the present invention is an earth provided separately from an electric conductor which is connected to a feeder line for transmitting a signal received from an antenna to a receiver or the like and which functions as an earth. A structure having a first end and a second end, the first end being connected to one end of an antenna feeder wire and the second end being open. It has a line part. The ground wire portion, from the first end portion to the second end portion, is provided so as to be insulated from the electric conductor and along the conductor, and is arranged on the vehicle. It is characterized in that it is attached to the vehicle side independently of the existing harness.

When the second end portion is released, the ground wire portion forms a transmission line, the electric potential becomes substantially zero at the first end portion, and substantially functions as the ground. Therefore, the performance of the antenna equipped with this ground structure is not impaired. Further, this earth structure does not need to be fixed because the second end is released, and is easy to install because it is provided on the vehicle side independently of the harness.

The above object can also be achieved by a grounding structure having the following specific structure. That is, according to a preferred aspect of the present invention, the desired grounding performance can be achieved by setting the length of the grounding wire portion in correspondence with the wavelength of the received radio wave. According to a preferred aspect of the present invention, the length of the ground wire portion is set such that the impedance with respect to the first end portion is substantially zero when the ground wire portion is viewed as a transmission line. To be done.

According to a preferred aspect of the present invention, the length of the ground wire portion from the first end portion to the second end portion is approximately λ / 4 with respect to the wavelength λ of the received radio wave. It is set.
According to a preferred aspect of the present invention, the ground wire portion is electrically connected via a predetermined insulating layer having a path reduction ratio δ (for example, an air layer or a paint layer of a vehicle body). It is provided along the conductor, and its length is set to δ · λ / 4.

According to a preferred aspect of the present invention, the ground wire portion is extended to the windshield of the vehicle so as to be suitable for a vehicle ground structure. The length of the ground wire portion can be shortened due to the track shortening effect of glass.

[0028]

BEST MODE FOR CARRYING OUT THE INVENTION An example in which the antenna of the present invention is provided on a glass, and particularly an embodiment applied to a windshield of an automobile, will be described below with reference to the drawings. In an embodiment described below, a glass antenna applied to a windshield (first embodiment), a glass antenna applied to a rear windshield (second embodiment),
A glass antenna (third embodiment) applied to a side glass is disclosed.

Further, an example in which the ground structure of the present invention is applied to the antenna of the above embodiment will be described with reference to FIGS. 61 to 60 and FIGS. 81, 82 and 99 to 111B. With respect to each of the glass antennas of these embodiments, it is possible to achieve a task specific to the installed glass position (a front windshield antenna secures a forward field of view, and a rear windshield antenna eliminates the influence of defogger). In addition to being described, their modifications (grounded antenna using a ground plate and grounded antenna using a ground wire) will also be described.

<First Embodiment> FIG. 1 shows a first embodiment of the present invention.
The windshield window 100 to which the glass antenna according to the embodiment is applied is shown as viewed from the outside of the front of the vehicle. That is, the right side of FIG. 1 corresponds to the left side of the driver in the vehicle, and the left side corresponds to the right side of the driver. The window glass 100 is provided with three antennas (10, 20, 30) stretched on the surface of the glass on the vehicle interior side. The antenna 10 is an antenna mainly for receiving FM radio waves and TV radio waves, and has a vertically long loop rectangular shape shown in FIG. 3, and a horizontal direction (vehicle width direction) length x ₁ (for example, 10 cm), It has a vertical length y ₁ (for example, 20 cm). The antenna 20 is a horizontally long loop rectangular antenna as shown in FIG. In addition, the antenna 3 provided on the rightmost side of the window 100
Reference numeral 0 denotes a circular loop-shaped antenna as shown in FIG. A diversity antenna system is constituted by these three antennas (10, 20, 30).

The horizontal length x and the vertical length y of these three antennas have the following relationship. That is, when the wavelength of the reception frequency is λ and the glass shortening rate is α, y ≦ λ / 4 · α (1) 60 cm−y ≧ x (2) What the expression (2) means (the sum of x and y is 60
Although not to exceed cm) will be described later, proper receiving sensitivity can be secured by setting the size of the antenna according to the equations (1) and (2).

In FIG. 1, the band region around the glass window 100, which is separated by a broken line, and the central band region of the glass window 100, which is surrounded by a broken line, are provided in Japan even if an opaque region is provided. Then, it is an area that does not violate regulations. Therefore, there is no problem even if the antenna is installed or set in this area. That is, windshield 1
When 00 is attached to the vehicle body, there is a ceramic coat or molding around the glass 100. Since ceramic coats and moldings are opaque, the regulations for attachments on windshields are "standard" at the point where the coatings or moldings cause a portion of the transparent glass 100 to be visible to the driver. If the coat or molding is above the glass 100, there is a transparent glass region below the reference line 100T, and if the coat or molding is below the glass 100, there is transparency above the reference line 100B. If there is a large glass area and the coat or molding is on the right side (in FIG. 1) of the glass 100, the reference line 1
If there is a transparent glass region on the left side of 00R and the coat or molding is on the left side of glass 100 (in FIG. 1), there is a transparent glass region on the right side of reference line 100L. The peripheral area of the glass 100 does not hinder the driver's view. Therefore, in FIG. 1, the reference line (10
0T, 100B, 100R, 100L) to the central direction of the glass window 100, there is no regulation on the attachment for a strip-shaped region with a width of 10 cm, so there is no legal regulation on the width of the glass antenna in this strip-shaped region. Absent.

The shape of the antenna will be described more specifically below. First, the shape of the antenna 10 will be described. The antenna 10 is an antenna having a shape in which the vertical direction is longer than the horizontal direction. As shown in FIG. 1, when such an antenna 10 is provided on the windshield, the center line 105 of the windshield is provided so as not to obstruct the front view of the driver (on the left seat in the United States and on the right seat in Japan).
It is provided so as to be symmetrically accommodated in a strip portion having a width of 66 mm.

The antennas 20 and 30 have a vertical length of 10
Antenna less than cm. Therefore, when such antennas 20 and 30 are provided above (or below) the window, there is no problem regarding the length in the vertical direction. Therefore, the size of the antennas 20 and 30 in the width direction can be determined according to the target frequency band and reception sensitivity regardless of the regulation. When the length of the antennas 20 and 30 along the vertical direction on the glass surface exceeds 10 cm in the downward (or upward) direction from the reference line, the antenna is set to have a width of 66 mm in the central portion of the glass. Try to fit within the range. That is, the reference line 1 of the antennas 20 and 30
It is preferable to set the width of the antenna portion below (or above) above 00 cm below (or above) 00T (or 100B) to 66 mm.

For antenna 20 (FIG. 4), x, y
Within the range that satisfies the above equations (1) and (2),
Set so that y2 is within 100mm so that the driver's view is not obstructed. For example, x ₂ = 15 cm, y ₂
= 65 mm. Similarly, for the antenna 30 (FIG. 5), its diameter x should be set so that it fits in a 100 mm band area.
₃ = y ₃ is set within 100 mm (for example, 80 mm).

Further, regarding the antenna 10, the vertical length L _y is set within 100 mm, and the horizontal length L _x is 6 mm.
Try to fit within 6 mm (eg 66 mm). In this way, all three antennas 10, 20, 30 are installed so that the driver's field of view is not hindered. The antennas 10, 20, 30 have a constant line width.

The antenna 10 is installed substantially at the center of the window 100. Normally in this position (eg in Japan)
"Vehicle verification" sticker will be attached. Vehicle verification seal is nominal 7
Although it has a size of 0 mm × 70 mm, as shown in FIG.
If the dimension inside the opening of the antenna loop is x ₁ 'L _y ', x ₁ '> 70 mm (3) L _y '> 70 mm (4) If the car verification sticker is inside the loop of the antenna 10, Will fit in. The vehicle verification sticker is required to be replaced regularly, but if the formulas (3) and (4) are satisfied, the conducting wire of the antenna 10 will not overlap with the position where the car verification sticker is stuck, and the user will need to seal the sticker. The antenna wire is not accidentally peeled off when replacing the.

The right side of the window 100 (when viewed from the outside) is also a place for sticking a regular inspection sticker in Japan. The regular inspection sticker has a circular shape. Therefore, if the dimensions inside the opening of the antenna loop are x ₃ 'and y ₃ ' and the size of this seal is S, as shown in Fig. 5, if x ₃ '= y ₃ '> S, then periodic inspection is performed. The replacement of the seal prevents the conductor wire of the antenna 30 from being unintentionally peeled off.

When the antenna pattern is actually set on the vehicle to which the vehicle verification sticker and the regular inspection sticker are attached, it becomes as shown in FIG. <Extending Antenna> First Embodiment Since the glass antenna according to the first embodiment is provided on the windshield, it is preferable that the glass antenna be easily attached.
For this purpose, the antennas 10, 20, 30 will be removed from the adhesive seal and mounted on the glass window.

There are various methods for spreading the three antennas shown in FIGS. 3 to 5 on the glass window surface. If the shape and the spread position are fixed, a thin plate-shaped wire is attached by a well-known method in a wind glass factory.
In this case, it is possible to set the wiring of the conducting wire for power feeding to the best position that does not hinder the visibility. Further, the ground wire can also be connected to the vehicle body so that the ground resistance is the smallest.

As in the first embodiment, whether or not the antenna is set on the windshield depends largely on the driver's preference. Therefore, in the first embodiment,
After the factory shipment, the normal driver adopts a method of easily spreading the antenna wire on the glass window. For that purpose, it is preferable to provide a seal coated with an adhesive layer on the antenna wire.

FIG. 6 shows a cross-sectional shape of such an antenna at the time when such an antenna is put on the market. That is, when the antennas 10 to 30 are commercially available, as shown in FIG. 6, the adhesive layer 62 is formed on the base paper layer 63, and the adhesive layer 62 and the antenna conductor layer 61 are provided between the adhesive layers 62. Is formed with an adhesive layer, and the adhesive layer 62 and the antenna conductor layer 61 are fixed to each other by the adhesive layer. Protective film 6 on the antenna conductor
0 is formed. The protective film 60 is formed only on the surface of the conductive wire and prevents oxidation of the conductive wire and protects it from damage. When the user pulls the base paper layer 63, the base paper layer 63 and the adhesive layer 62 are separated from each other, and the adhesive layer 62 is exposed. The user attaches the antenna with the exposed adhesive layer 62 to a desired glass-like position. The antenna is preferably attached to the inside of the window in consideration of weather resistance.

<Relationship between Dimension x and Dimension y> First Embodiment FIG. 7, FIG. 9, FIG. 11, FIG. 13, FIG. 15, FIG.
9 and 21 show the antenna 10 as an example.
Shows the receiving sensitivity to the received radio waves in the FM radio band and the VHF band of the TV when the height (= y) is set to a certain value and the width x is variously changed. Similarly, FIG. 8, FIG.
12, FIG. 14, FIG. 16, FIG. 18, FIG. 20, and FIG. 22 show the average receiving sensitivity.

For example, in FIG. 7, the receiving sensitivity when the height y is fixed to 5 cm and the width x is set to 0.5 cm is represented by the curve I, and the receiving sensitivity when the width x is set to 2 cm is represented by the curve. The curve II represents the receiving sensitivity when the width x is set to 5 cm, and the curve IV represents the receiving sensitivity when the width x is set to 10 cm.
The receiving sensitivity when set to cm is represented by curve V,
Curve VI represents the receiving sensitivity when the width x is set to 25 cm, curve VII represents the receiving sensitivity when the width x is set to 30 cm, and curve VIII represents the receiving sensitivity when the width x is set to 40 cm. , The receiving sensitivity when the width x is set to 50 cm is represented by the curve VIIII, and the receiving sensitivity when the width x is set to 60 cm is represented by the curve X. Further, FIG. 8 is an average of the 10 test reception sensitivity values within the evaluation frequency range.

For the graph of FIG. 9 (y = 10 cm), FIG.
A table of average reception sensitivities of 0 corresponds. The graph (y in FIG. 11
= 15 cm) corresponds to the average reception sensitivity table of FIG. The graph of FIG. 13 (y = 20 cm) corresponds to the table of the average receiving sensitivity of FIG. The graph of FIG. 15 (y = 25
cm) corresponds to the average reception sensitivity table of FIG. The graph of FIG. 17 (y = 30 cm) corresponds to the average reception sensitivity table of FIG. The graph of FIG. 19 (y = 35 cm) corresponds to the table of average reception sensitivity of FIG. The graph of FIG. 21 (y = 40 cm) corresponds to the table of average reception sensitivity of FIG. These figures show that the antenna 10
(Or the antennas 20 and 30) have a height y of about 4
A practical sensitivity can be obtained up to about 0 cm, and generally, y ≦ λ / 4 · α (λ is the wavelength of the received radio wave).

When the trends in FIGS. 7 to 22 are summarized, x
When ≈y, the receiving sensitivity is low, but x> y or x <
When y (that is, the vertical and horizontal lengths are made different), relatively high reception sensitivity can be obtained. That is, vertical length (height y)
Is in the range of 0 to λ / 4 · α and is relatively short compared to the lateral length x (y <x), good reception sensitivity can be obtained in the high frequency region, and This high reception sensitivity characteristic can be obtained for a wide range of width x. on the other hand,
When y is in the range of 0 to λ / 4 · α and is relatively long with respect to x (y> x), good reception sensitivity can be obtained in a relatively low frequency region, and this high reception is achieved. It can be seen that the sensitivity characteristic can be obtained for a wide range of width x.

Further, in the range of 8 cm ≦ y ≦ 40 cm x ≦ 30 cm, the ideal receiving sensitivity can be obtained in the frequency band centering on the VHF band of TV, and the receiving sensitivity can be changed by changing the width x. It can be seen that the bandwidth that can be secured is changing. It can be seen that when the sum of x and y exceeds 60 cm, the receiving sensitivity decreases.

Considering the legal regulation range shown in FIG. 1, 7 cm ≦ x ≦ 30 cm and 7 cm ≦ y ≦ 10 cm are more preferable. 44 to 49, the received radio wave is UH.
It shows that the reception sensitivity of -20 dB can be achieved if the antenna width is 40 cm or less in the F frequency band. 44 and 45 show the results when the antenna width length x was variously changed while fixing y = 3 cm. That is, when the antenna width x is 5 cm: Curve I, 10 cm: Curve II, 15 cm: Curve III, 20 cm: Curve IV, 25 cm: Curve V, 30 cm Time: Curve VI, 35 cm: Curve VII, 40 cm: Curve VIII. Further, FIGS. 46 and 47 show the case of FIG. 4 when y = 5 cm.
8, FIG. 49 shows the case where y = 10 cm.

When α is set to 0.6 (glass antenna shortening rate) in the above formula (1), the formula (1) shows that y is 10 cm or less (for radio waves of 450 Mhz or more) to receive the UHF frequency band. It is preferable that the length is from an area that does not obstruct the driver's field of view for an antenna installed on the windshield of a vehicle, that is, from the window end (or the reference line). It can be installed in the area of up to 10 cm, which is convenient. Therefore, the antenna suitable for the UHF frequency band is preferably set to 5 cm ≦ x ≦ 40 cm y ≦ 10 cm, and the lower limit of y is 3 cm ≦ y ≦ 10 cm in order to secure the receiving sensitivity.

FIG. 23 shows FIGS. 7 to 22 and FIGS. 44 to 4.
The results shown in FIG. 9 are summarized and the relationship between x and y is represented as a graph. In the figure, the line segment AB is a linear straight line x + y = 60 cm. This is an equation showing that the critical value of the sum of the width x and the height y for ensuring the reception sensitivity is 60 cm, which is surrounded by the line segment AB and the x-axis and the y-axis. The area is expressed as x + y ≦ 60 cm.

In FIG. 23, the triangular area ABO is
This is an area where the antenna system including the antennas 10, 20, and 30 exhibits better performance than the conventional unipole antenna. Further, the area CDEHJKL is an area where a practical high sensitivity can be obtained over the FM frequency band and the VHF frequency band. The area HFGLKJ is an area in which a practical high sensitivity is obtained in the VHF frequency band for TV. The region PQRS is a region where practical high sensitivity is obtained in the UHF frequency band for TV. Note that x = 2 indicated by the line segment CG
cm is the minimum antenna width for which a practical effect is recognized. Further, y = 8 cm indicated by the line segment GF is the minimum antenna height at which a practical effect as a television antenna centering on VHF is recognized.

<Influence of Feeding Point> First Embodiment FIGS. 24 to 43 show how the receiving sensitivity depends on the position of the feeding point at the center and at the end of the antenna side. It shows how to change. In each of the graphs of FIGS. 24 to 43, the solid line indicates that the feeding point is located at the end portion, and the broken line indicates that the feeding point is located at the center portion. The numbers in the graph show the average sensitivity within the evaluation frequency range.

The feeding point of the antenna in the present invention means the point closest to the receiver in the portion acting as the antenna. In the frame-type antennas of all the embodiments of the present invention (the above-mentioned and later-described embodiments), since the joint between the frame-shaped portion and the leader line up to the feeder acts as an antenna, the joint with the leader line is performed. The part is defined as the feeding point in the embodiment.

The antenna system of the first embodiment achieves the target of -20 dB, but especially when the feeding point is installed at the end, the antenna set as x> y has a receiving sensitivity in the UHF band. You can see that has improved. <Setting of Antenna Dimension> First Embodiment Next, a designing method for providing the antenna of the first embodiment on an actual windshield of a vehicle will be described. This design method is based on the above-mentioned requirements for securing the driver's view,
Also, it must satisfy the requirements for compatibility between reception sensitivity and bandwidth expansion.

First, the vertical dimension y is determined. The vertical length y of the antenna is λ for the wavelength of the reception frequency and α for the glass shortening rate.
Then, it is almost determined by λ / 4 · α. First
In the embodiment, the antennas 10, 20, 30 in FIG.
Are set to receive radio waves in different frequency bands, the vertical length y of each of these antennas is α = 0.6,
20 cm aiming at the 225 MHz band, 562.
It is set to 8 cm for 5 MHz and 6.5 cm for 692.3 MHz (FIGS. 3 to 5).

Then, the lateral dimension x is set. The lateral dimension affects the spread of the band in which the receiving sensitivity can be secured, as described above. As a tendency, the wider the band, the wider the band, but if it is too wide, the receiving sensitivity will decrease. The limit is the vertical dimension y
And the lateral dimension x is 60 cm (x + y = 60).

Since TV radio waves have a wide frequency band (VHF9
(0 MHz to UHF770 MHz) One antenna cannot cover. Therefore, of the three antennas 10, 20, and 30, 90 MHz to 230 MH can be obtained by the antenna 10.
Mainly z of VHF band of TV, with antenna 20 500MH
z ~ 770MHz, antenna 30 470MHz ~ 60
The width is set so that it mainly covers the UHF band of 0 MHz of each TV, and the width of each is shown in FIG.
˜10 cm, 15 cm, and 8 cm as shown in FIG. Further, the antenna 20 and the antenna 30 are overlapped in the band that can be covered, and the antenna system formed by the respective antennas is an effective diversity system.

The antenna 10 provided at the center of the window has an inverted convex shape as shown in FIG. 3 because the width of the lower part needs to be suppressed to 6.6 cm or less in order to secure the driver's field of view as described above. Become. The antenna 30 is 8 cm
It has a size of 8 cm by which the regular inspection sticker is enclosed, and the reception band is determined by the maximum value of the vertical dimension and the horizontal dimension and does not depend on the shape.

The antenna 20 is installed between the antenna 10 and the antenna 30. In order to secure the driver's field of view, it is desirable not to provide an antenna in a part inside 10 cm from the end of the part that does not obstruct the field of view of the window as described above, except for the central part of the window. An antenna for receiving a relatively low frequency (VHF) with a long vertical dimension is installed in the center of the window, and an antenna for receiving a high frequency with a short vertical dimension is installed in the other portion.

<First Modification of First Embodiment> The antenna 10 provided on the windshield of the first embodiment has a VH
As shown in FIG. 3, it had a vertically long convex shape mainly for reception of the F frequency band. The first modified example to be described below is an antenna 110 having a horizontally long concave shape as shown in FIG. 50 for the purpose of receiving radio waves in the same frequency band. That is, the dimensions of the antenna 110 are x ₁ = 22 cm, y ₁ = 9 cm, and L _y = 8 cm.

As shown in FIG. 51, the antenna 110 of this modification is effective for a vehicle in which the room mirror 101 is attached to the base 103 directly provided on the windshield. The vertical length is the first
For the same reason as the embodiment (being able to enclose the vehicle verification and secure visibility), it is set to 9 cm, which is 7 cm or more and less than 10 cm. The concave notch 102 (FIG. 50) is provided in order to prevent the antenna wire from interfering with the base 103.

The basic design concept regarding the dimensions of the antenna of the first modified example is that the vertical length y is set in the range of 7 cm to 10 cm from the request of securing the visibility and surrounding the vehicle verification. If y is set to y = 7 to 10 cm, the frequency band λ adapted to this length corresponds to λ = (4y / α), where α is the shortening rate of the glass, and this wavelength is a TV in the UHF band. It is a radio wave. First
The antenna of the modified example is a kind of frame-shaped antenna, and has a property that the band of the frequency band can be widened by increasing the lateral length x as a characteristic of the frame-shaped antenna. Therefore, in the first modified example, by setting the lateral length x to be sufficiently long, for example, 22 cm, it has succeeded in extending the reception band to the VHF band.

52 to 57 show the FM frequency band (88 to 110 MH) of the concave antenna according to the first modification, respectively.
z), VHF frequency band (170 to 225 MHz), and UHF frequency band (470 to 770 MHz) radio wave (horizontal polarized wave) sensitivity characteristics (shown by curves I in FIGS. 52, 54, and 56) are shown. . As a comparison target, the characteristics of the antenna 20 of the first embodiment (that is, a horizontally long frame shape) antenna (similarly curve II) and the characteristics of the antenna 30 of the first embodiment (that is, a round frame shape) (similarly curve III). ) Is shown in FIG.

52 to 57 show that the concave antenna of the first modification example has a frequency range of -13.7 to -16.2 dB in each frequency band.
(See FIG. 53, FIG. 55, and FIG. 57) and shows that the antenna sensitivity is practically acceptable. Incidentally, FIG.
In the experiments of 2 to 57, the "open type ground wire" described later was used as the ground of each antenna. And
The length of the "open type ground wire" of the antenna 20 is 30 cm,
The length of the ground wire of the antenna 30 was set to 15 cm.

<Second Modification of First Embodiment> This second modification is an antenna 120 for the FM band.
In the first embodiment, the antenna 10 is used as the TV antenna and the FM antenna, but in the second modification, the FM of the radio is used.
Radio waves and VICS (Vehicle Information & Communication)
The purpose is to receive radio waves for System) with diversity.

The shape of the antenna 120 of the second modification is shown in FIG.
8 shows. Longer in the lateral direction (35 cm) than the first modification (y = 22 cm) in order to improve the reception sensitivity in the FM band.
doing. As shown in FIG. 59, the two antennas 120
The diversity system is constructed by providing. The design concept of the second modified example is basically the same as that of the first modified example, but in order to make FM reception the main purpose, the lateral width x is defined by the above equations (1) and (2) (further , X =
7 to 10 cm) is the maximum length that can be satisfied.

As shown in FIG. 59, the antenna 120
If does not interfere with the base 100, the notch is unnecessary in the second modification. FIG. 60 shows the reception sensitivity characteristic of the antenna 120 of the second modified example in the FM radio wave region. At this time, the average sensitivity Pw-AV shows -10.5 dB, and VI
It can be seen that the CS antenna has sufficient performance.

It should be noted that the second method in consideration of the legal regulation shown in FIG.
The preferable ranges of the modified examples are x ≧ 30 cm and 7 cm ≦ y ≦ 10 cm. <Open end type ground wire> ... Applicable in common to the first to third embodiments. The open end type ground wire to be described below does not use any ground plate or the like and is composed of only bendable conductor wires. Is. This open-type ground wire is not limited to the antenna of this embodiment, but can be applied to all ground-type antennas.

FIG. 61 shows a feeder assembly using an open type ground wire. In the figure, reference numeral 150 denotes a joint box, which is the end portion 1 of the antenna 10, 20, 30 or the like of the first embodiment.
It has a slit 155 into which 1, 21, 31 are inserted.
A feeder line 152 and a ground line 151 are connected to the box 150. The feeder wire has a ferrite core 53 and a connector 154 for the purpose of removing noise.
Is attached. The connector 154 is connected to an FM radio or TV tuner or a VICS terminal (not shown) according to the purpose.

As shown in FIGS. 62 and 63, the feeder wire 152 has a net-like shield wound around a signal core wire 156. An elastic spring body 158 for locking the end of the antenna is provided in the box 150, and the core wire 156 is connected to the spring body 158. In addition, the shield is put together and the ground lead wire 1
57, and the lead wire 158 is a thicker earth core wire 1
57. The ground core wire 159 is covered with an insulating coating and becomes the ground wire 151 as a whole.

FIG. 1 shows a state in which such an earth wire assembly is connected to the antenna 10 and attached to the windshield.
08. In FIG. 108, the ground wire assembly (the assembly of the ground wire, the feed line, and the joint box) is subassembled in advance. Then, the joint box is inserted on the glass surface, and the ground wire and the power supply wire are inserted inside the ceiling panel of the body. At the time of this insertion, the power supply line is attached to the inner surface of the panel by a desired method such as bonding. As described above, the ground wire, the power supply wire, and the joint box are used as a sub-assembly, and the sub-assembly is attached to the vehicle by retrofitting, which makes it extremely easy to attach the antenna after the vehicle is assembled. Further, by attaching the ground wire to the power supply line in advance, it is not necessary to consider the attachment of the ground wire at the time of retrofitting the antenna, so that the attachability is further improved. Further, as shown in FIG. 62, since the ground wire is covered with insulation, it is easy to maintain the insulation with the vehicle body when the ground wire is inserted into the body panel.

Although the feeder wire and the ground wire of the ground wire assembly are inserted in the body panel in the example of FIG. 108, when the end user finds it difficult to insert the feeder wire and the ground wire, May be made to crawl along a periphery of the body panel (for example, a body trim plate) to a place where it is as invisible as possible. This kind of routing
This is possible because the ground wire assembly of this embodiment does not require the ground wire to be directly attached to the vehicle body.

When the ground wire assembly of FIG. 61 is attached to a vehicle, the ground wire assembly is inevitably set separately from other wire harnesses (not shown in FIGS. 61 and 108). Here, the other wire harness is a wire harness different from the harness of the present antenna assembly. The open end type ground is characterized in that its end 160 is open, and it does not need to be grounded to the vehicle body. It functions as a ground even if the end is open. The reason will be described with reference to FIGS. 64 to 67.

FIG. 64 shows the structure of an ordinary conventional grounding type antenna. As shown in the figure, the ground wire of the feeder wire is grounded to the vehicle body. On the other hand, FIGS. 65 to 67 explain the principle of an open end type ground wire as an embodiment of the present invention.
As shown in FIG. 65, when one end of an open end type ground wire having an arbitrary length is released, the ground wire 151 and the vehicle body metal form a transmission line. The voltage distribution on the ground wire at this time has a curve along the ground 151, such as the curve 171 in FIG. That is, the potential on the ground wire tends to gradually decrease. Here, as shown in FIG. 66, the ground wire 1
If the length of 51 is set to 1/4 of the wavelength λ of the received radio wave, the voltage distribution on the line looks like the curve 173 (Fig. 66), and the impedance of this transmission line seen from the point 172 is due to the nature of the transmission line. Becomes 0, and the potential at the point 172 becomes equal to the vehicle body potential. That is, as shown in FIG. 67, the open end type ground wire whose length is set to λ / 4 is equivalent to the ground wire directly grounded to the vehicle body at the point 172.

In the examples of FIGS. 65 to 67, an air layer exists between the ground wire forming the transmission line and the vehicle body, but an insulator made of an arbitrary material (having a line shortening rate δ) is interposed between them. With the interposition, the preferred length of the open-ended ground wire is (λ / 4) · δ (5).

What is important here is that the open-ended ground wire does not have to be parallel to the feeder line, and for the purpose of forming a transmission line with the vehicle body, it does not have to come in contact with the metal portion of the vehicle body and runs along the line. It would be good if Further, the open end type ground wire is preferably a conductor which can be bent so as to follow the body body when the position where the ground wire is to be set is a place where the space is narrow.

Considering the ease of incorporating the open end type ground wire into the body of the vehicle body, in FIG. 61, the feeder wire 152 and the ground wire 151 are insulated from each other, and both wires are insulated from the body body. So that it is preferably covered with an insulating coating. Therefore, the open end type ground wire assembly can be configured separately from other wire harnesses.

Thus, the open-ended ground wire is grounded more than the conventional grounding method or the grounding plate (FIG. 11) of this embodiment, which requires some construction such as screwing, bonding, and a grounding pattern. The effect is that it is extremely easy to take. The performance of the open-ended ground wire having an extremely advantageous configuration in terms of grounding as ground will be described below. FIGS. 68 to 73 show an open-ended ground wire connected to the convex antenna 10 of the first embodiment. Fig. 7 shows VSWR characteristics when the length of the open-ended ground wire is variously changed when receiving TV radio waves in the band of 90MHz to 230MHz. For comparison, FIG. 74 is a VSWR characteristic diagram when the antenna 10 and the ground plate of FIG. 11 are combined, and FIG. 75 is a VSWR characteristic diagram when the antenna 10 is not grounded. The VSWR characteristic diagram when the antenna 10 is directly grounded to the vehicle body (the length of the ground wire is about 15 cm) is shown.
If it is most preferable to provide the earth directly or the earth plate to the body from the viewpoint of maximizing the earth function, the VSWR characteristic shown in FIG. 74 or 76 is the antenna 10 (FIG. 3). Therefore, an open-ended ground wire having a characteristic of FIG. 72 or 73 closest to the VSWR characteristic, that is, a ground wire having a length of 50 cm to 60 cm is preferable. .

Thus, the length of the open end type ground wire is δ · λ / 4 depending on the wavelength of the received radio wave (where δ is the line shortening rate of the substance interposed between the ground line and the vehicle body). By setting to, it is possible to provide a ground wire with simple setting and optimum reception performance. Next, the influence of the open end type ground wire on the reception sensitivity will be described. 77 to 84
Shows the receiving sensitivity of the convex antenna 10 shown in FIG. 3 (also referred to as a T-shaped antenna in the drawing). 77, 79,
81 and 83, the curve I shows the characteristics of the antenna 10 when an open-ended ground wire is connected to the antenna 10.
The broken line II shows the characteristics of the antenna 10 when the ground plate (FIG. 7) to be compared is connected to the antenna 10. In particular, FIG.
7, FIG. 78 shows the receiving sensitivity when the length of the open end type ground wire is set to 90 cm in order to receive the radio wave in the 88 to 110 MHz band, and from FIG. 78, the average sensitivity of −13.3 dB is sufficient as the sensitivity. You can see that you are getting. FIG.
9, FIG. 80 shows the receiving sensitivity when the length of the open end type ground wire is set to 53.5 cm in order to receive the radio wave in the 170 to 225 MHz band, and from FIG. It can be seen that 0.3 dB is obtained. Also,
81 and 82 show the receiving sensitivities when the length of the open end type ground wire is set to 30 cm in order to receive the radio waves in the 170 to 225 MHz band, and from FIG. 82, a sufficient average sensitivity of -12. It can be seen that 3 dB is obtained. Also,
83 and 84 show the receiving sensitivities when the length of the open end type ground wire is set to 20 cm in order to receive the radio waves in the 470 to 770 MHz band, and from FIG. 84, the average sensitivity -17. It can be seen that 4 dB is obtained.

Further, the graphs of FIGS. 77, 79, 81, and 83 show that if the length of the open-end type ground wire is set appropriately, the ground plate will exhibit comparable characteristics. There is. FIG. 87 shows the sensitivity when radio waves in the 470 MHz to 770 MHz band are received by the long frame-shaped antenna 20 of FIG. 4. In the figure, the solid line I sets the length of the open end type ground wire to 10 cm, and the broken line. II shows the characteristics when a ground plate is used.

From the above various experiments, when the open-ended ground wire is applied to the convex antenna such as the antenna 10, the maximum horizontal length x and the maximum vertical length y are y ≦ Set so that α · λ / 4 x ≤ 60 cm-y is satisfied, and further set the width of the portion below the 10 cm position from the upper end of the field of view of the windshield (the above-mentioned reference line) to 6.6 cm or less. It can be seen that the preferred antenna device can be used.

When the open-ended ground wire is applied to a rectangular antenna as shown in FIG. 4, the maximum horizontal length x and the maximum vertical length y of the antenna are 5 cm ≦ x. It was found that a preferable result of ≦ 40 cm 3 cm ≦ y ≦ 10 cm was obtained.

When the open-ended ground wire is applied to the circular antenna having a 7 cm inner diameter shown in FIG. 5, the maximum horizontal length x and the maximum vertical length y of the antenna are y ≦ α A preferable result was obtained in which λ / 4 x ≦ 60 cm-y.

<Second Embodiment> ... Side glass antenna In the second embodiment, the glass antenna of the present invention is applied to a side glass. Particularly in the case of a wagon type vehicle, the side glass is not opened and closed, and there is no problem even if a glass antenna is provided there. Also, VIC
Since the S antenna needs to be provided separately from the TV antenna, when the VICS antenna is provided on the windshield as in the first embodiment (FIG. 50), the windshield is occupied by many antenna wires. It may be unfavorable depending on the type of vehicle. In the antenna of the second embodiment, the VICS antenna is provided on the side glass.

As the glass antenna of the second embodiment, a frame-shaped antenna is adopted, and the glass antenna designing method of the first embodiment (1 and 2 formulas and design conditions of FIG. 23) is applied. FIG. 89 shows the frame-shaped glass antenna 2 of the second embodiment.
00 shows the state of attachment to the side glass. The open end type ground wire (FIG. 61) of the first embodiment is connected to the antenna 200 of FIG. 89. In this antenna assembly, the ground wire is attached to the inner surface of the body panel of the vehicle body by an adhesive seal or the like. Since this bonding does not need to electrically connect the ground wire to the vehicle body, as in the example of FIG. 108,
When the antenna of FIG. 89 is retrofitted to the vehicle body, the mounting becomes simple. Note that FIG. 89 shows that the antenna of the present embodiment can be set independently of other various wire harnesses. The antenna 200 of FIG. 89
Will have all the features of the frame-shaped antenna of the first embodiment. Further, by connecting the antenna 200 to the open end type ground wire, all the characteristics of the open end type ground wire of the first embodiment are inherited.

When the above formulas (1) and (2) and the design conditions of FIG. 23 are applied to the glass antenna of the second embodiment, x ≦ 30 cm 20 cm ≦ y ≦ 40 cm is a preferable dimension for the glass antenna of the second embodiment. Become.

The frame-shaped glass antenna of the second embodiment does not limit its ground to an open-ended ground wire, as long as the above design conditions are satisfied. In FIG. 90, the antenna 2
The state of attachment when 00 is connected to the ground plate is shown. 92 to 102 show that the open type ground wire is connected to the VICS frame type antenna 200 of the second embodiment to obtain 76 MHz to
The VSWR characteristics when the length of the open-ended ground wire is variously changed when receiving TV radio waves in the band of 108 MHz are shown. For comparison, FIG. 91 shows the characteristics of the antenna without ground, FIG. 103 shows the VSWR characteristics diagram of the antenna in which the antenna 200 and the ground plate are combined, and FIG. 104 shows the characteristics of the antenna in which the antenna 200 is directly grounded to the vehicle body. VSW
An R characteristic diagram is shown.

The VSWR characteristic of FIG. 103 shows that the antenna 200 of the second embodiment provided with the ground plate has an F in the VICS band.
It is said that it is suitable for receiving M radio waves. Also,
From the graphs of FIGS. 92 to 102, when the antenna 200 of the second embodiment connected to the open end type ground wire is used for receiving FM radio waves in the VICS band, the length of the open end type ground wire is 80 cm ( 99) or 90 cm (Fig. 100)
It turns out that it is preferable to set to.

105 and 106 show the receiving sensitivity characteristics when the open end type ground wire is set to 90 cm and the VICS antenna 200 is provided on the side glass. still,
In FIG. 105, the broken line shows the characteristic when the ground is directly connected to the body of the comparison target. <Third Embodiment> As a third embodiment of the present invention, a glass antenna provided with a rear window glass is proposed. In the glass antenna of the third embodiment, the frame-type antenna used in the first and second embodiments is installed on the rear window glass.

FIG. 107 shows an interior view of a vehicle in which the glass antenna 270 according to the third embodiment of the present invention is installed on the rear window glass, as seen from below the inside of the vehicle. 2 in the figure
Reference numeral 50 is a windshield, 251 and 252 are side glasses, and 253 is a rear glass. A defogger 254 is provided on the rear glass 253, and an antenna conductor wire 262 is vertically provided at the center of the defogger 254 in the vehicle width direction. The conductor 262 vertically intersects with each heating wire of the defogger 254 and is connected in a direct current manner.

There is a region where the defogger heat rays are not stretched above the rear window glass 253, and the radio (or TV) antennas 260, 26 are provided in this blank region.
1 and a VICS antenna 270 are installed.
In FIG. 107, the antennas 260 and 261 are in the shape of an eye, and the VICS antenna 262 is in the shape of a frame. The ground wire assembly of FIG. 107 can be attached to the vehicle body by the same method as the method of attaching the ground wire assembly of FIG. 108 to the vehicle body.

The lowest width conductor wires of the antennas 260 and 261 are the highest heat wires 254t of the defogger 254.
Close to. Therefore, each of the antennas 260 and 261 is capacitively coupled to the conductor wire 262 provided in the defogger in the vertical direction through the defogger heat wire 254t. Similarly, the VICS antenna 270 is also capacitively coupled to the conductor antenna 262.

The three antenna lines are capacitively coupled to the antenna conductor 262 as follows. That is, the vertical length of the antennas 270, 260, 261 is generally y
And the antenna shortening rate by the length L of the antenna conductor 262 is ω, the lengths of the respective antennas in the vertical direction y are adjusted so as to satisfy 20 cm ≦ y + ω · L ≦ 70 cm.

The details of the capacitively coupled open-ended ground wire are described in Japanese Patent Application No. 6-205 by the inventors of the present invention.
No. 767. In this case, especially VI
Regarding the antenna 270 for CS, the above (1),
In addition to satisfying the expression (2), it is necessary to satisfy the design condition shown in FIG. Then antenna 2
As for 70, x ≦ 30 cm, 20 cm ≦ y + ωL ≦ 40 cm are preferable dimensions.

As the ground of the VICS antenna 270, the above-mentioned open end type ground wire was used. According to the antenna system of the third embodiment, radio and TV radio waves and VI
A diversity system that receives CS radio waves can be provided. In the antenna system of the third embodiment, the first
All the advantages of the antenna of the embodiment and the advantages of the open end type ground wire are inherited.

<Further Modifications> The first to third embodiments can be variously modified without departing from the spirit of the present invention. The shapes of the glass antennas of the first to third embodiments are a convex shape (T shape), a long frame shape, and a round shape, but the present invention can be applied to any antenna having a frame shape. . In this case, the frame may be located near the feeding point.

In the formula (2) applied to the frame type glass antennas of the first to third embodiments, 60 cm is set as the critical value because glass is the base, but if the base is glass If the material is other than the above (track reduction rate γ),
The 60 cm in the equation (2) is generally a predetermined 100 × γ cm. If the shortening rate γ of the base is smaller than that of glass (α≈0.6), 100 × γ will be a value smaller than 60 cm, and in this case, the size of the antenna itself can be reduced.

The open end type ground wire used in the first to third embodiments was used in the form of being bundled together with the feeder wire, but the ground wire applied to the present invention is For example, as shown in FIG. 109, a conductor on a thin thin sheet is used as the open-ended ground wire, and this conductor is spread as an open-ended ground wire on the glass surface apart from the feeder line. Is also good. The method of fixing the ground wire on the glass surface facilitates retrofitting of the antenna. The feeder wire shield and conductor are connected in the joint box. In this case, since glass (shortening rate α) exists between the ground wire and the body of the vehicle body, the optimum length of this open end type ground wire is (λ / 4) according to the equation (5).・ It becomes α.

110A and 110B show an antenna 10 (the same shape as the antenna 10 of FIG. 1) in which the open-ended type earth of the present invention is provided on the surface of the windshield 500.
Two examples applied to the ground for
A and FIG. 111B respectively show two examples in which the open-ended ground of the present invention is applied to the ground for the antenna 400 (same as the antenna pattern shown in FIG. 99) provided on the rear window glass 510 surface. Show. That is, FIG.
Ground wire 1 of A, FIG. 110B, FIG. 111A, and FIG. 111B
51 is different from the earth in FIG. 61 in that it is provided on the glass.

The grounds of FIGS. 110A and 110B are ground wires 151 provided on the surface of the glass 500 and near the metal of the vehicle body at the periphery of the glass 500.
And a shield wire of the feeder wire 152 and a joint box 15 for connecting the shield wire and the ground wire 151.
It consists of 0. Note that reference numeral 450 denotes an arbitrary wire harness other than a harness forming a part of the antenna. That is,
The antenna ground wire of FIGS. 110A-111B can also be separate from other wire harnesses.

The joint box 150 of FIG. 110A.
Are positioned outside the gas 500 such that they are out of the driver's view. Therefore, the box 150 needs to be fixed in the frame of the vehicle body so that the ground wire 151 does not come off from the box 150. On the other hand, the joint box 150 of FIG. 110B is fixed on the surface of the glass 150 (for example, with an adhesive sheet). In the example of FIG. 110B, although the box 150 is within the driver's view,
Since it is not necessary to push the box itself into the vehicle body, it is more advantageous when the ground is attached after the vehicle is assembled, as compared with the example of FIG. 110A.

The earth shown in FIGS. 111A and 111B is an example in which the earth of the present invention is applied to the rear window glass 510. In these figures, 401 is a defogger heat wire, and the second antenna wire 402 is orthogonal to and electrically connected to the defogger heat wire 401 on the glass surface at the center position of the heat wire 401 in the vehicle width direction. Has been extended. Further, the rectangular first antenna wire 400 extends on the glass surface at a position where the second antenna wire 402 and the uppermost defogger heat wire are capacitively coupled. The first antenna line 400 is the second antenna line 402.
The principle of functioning as a high-performance antenna through capacitive coupling with the antenna is described in US Application No. 08/362,
788, the contents of which are incorporated herein by reference.

The ground structure of FIG. 111A is the same as that of FIG. 110A, and the ground structure of FIG. 111B is shown in FIG.
Same for 10B ground. 110A and 110
The ground wire 151 in FIGS. B, 111A, and 111B can be spread on the glass surface by various methods. For example, when installing the ground of the present invention on glass after assembling an automobile, it is preferable to bond the ground wire 151 to the glass with an adhesive sheet or the like. When it is possible to set the ground in an automobile assembly plant, it is preferable to vapor-deposit the ground wire 151 on the glass in the assembly process in view of ensuring strength.

The antenna of the above-described embodiment had a special shape in consideration of the case where "vehicle verification" or "regular point verification", which is a system peculiar to Japan, is attached to the windshield. On the other hand, in some countries, such as the United States, it is not necessary to attach these certificate seals. Therefore, the shape of the glass antenna of the present invention, if the law or regulation of the applicable country or state obliges to affix some certificate in place of "vehicle verification" or "regular point verification", It should be changed according to the shape.

[0105] In the name of ensuring the driver's field of view,
The regulations for attaching a thing that blocks the view of the user or the automobile manufacturer to the wind glass also vary depending on the country, the state or the territory. Therefore, as in the case of a certificate, the shape of the glass antenna of the present invention should be changed according to the laws or regulations concerning the visibility of the driver in the applicable country or state.

The grounding structure of the above embodiment should be determined according to the frequency of the received radio wave.
The following table shows each country (Japan, Korea, ADR, European countries E
CE, USA, etc.) AM, FM, T
The frequency band of V or long wave (LW) radio waves is shown.

[0107]

[Table 1]

[0108]

As described above, according to the present invention,
We were able to provide a grounding structure that was easy to install while ensuring antenna performance. Further, according to the present invention, it is possible to provide an antenna device which can be easily attached while ensuring the antenna performance and the field of view.

[Brief description of drawings]

FIG. 1 is a diagram showing a windshield of a vehicle to which an antenna system according to a first embodiment of the present invention is applied.

2 is an external view of the vehicle when the antenna of FIG. 1 is attached to the vehicle.

3 is a diagram showing a configuration of an antenna 10 applied to the system of FIG.

FIG. 4 is a diagram showing a configuration of an antenna 20 applied to the system of FIG.

5 is a diagram showing a configuration of an antenna 30 applied to the system of FIG.

6 is a cross-sectional view showing the structure of an antenna product before the antenna of FIG. 1 is spread.

FIG. 7 is a diagram showing changes in average reception sensitivity when x is variously changed when y = 5 cm.

FIG. 8 is a diagram showing a change in reception sensitivity averaged within an evaluation frequency range when x is variously changed when y = 5 cm.

FIG. 9 is a diagram showing changes in average receiving sensitivity when x is variously changed when y = 10 cm.

FIG. 10 is a diagram showing changes in reception sensitivity averaged within an evaluation frequency range when x is variously changed when y = 10 cm.

FIG. 11 is a diagram showing a change in average reception sensitivity when x is variously changed when y = 15 cm.

FIG. 12 is a diagram showing changes in reception sensitivity averaged within an evaluation frequency range when x is variously changed when y = 15 cm.

FIG. 13 is a diagram showing a change in average reception sensitivity when x is variously changed when y = 20 cm.

FIG. 14 is a diagram showing changes in reception sensitivity averaged within an evaluation frequency range when x is variously changed when y = 20 cm.

FIG. 15 is a diagram showing a change in average receiving sensitivity when x is variously changed when y = 25 cm.

FIG. 16 is a diagram showing a change in reception sensitivity averaged in an evaluation frequency range when x is variously changed when y = 25 cm.

FIG. 17 is a diagram showing a change in average reception sensitivity when x is variously changed when y = 30 cm.

FIG. 18 is a diagram showing changes in reception sensitivity averaged within an evaluation frequency range when x is variously changed when y = 30 cm.

FIG. 19 is a diagram showing changes in average reception sensitivity when x is variously changed when y = 35 cm.

FIG. 20 is a diagram showing changes in reception sensitivity averaged within an evaluation frequency range when x is variously changed when y = 35 cm.

FIG. 21 is a diagram showing changes in average reception sensitivity when x is variously changed when y = 40 cm.

FIG. 22 is a diagram showing changes in reception sensitivity averaged within an evaluation frequency range when x is variously changed when y = 40 cm.

FIG. 23 is a graph showing the relationship between the height x and the width y of the antenna system of the embodiment.

FIG. 24 is a diagram showing a change in receiving sensitivity when the feeding position is changed with x = 10 cm and y = 10 cm.

FIG. 25 is a diagram showing a change in receiving sensitivity when the feeding position is changed with x = 15 cm and y = 10 cm.

FIG. 26 is a diagram showing a change in reception sensitivity when the feeding position is changed with x = 20 cm and y = 10 cm.

FIG. 27 is a diagram showing a change in receiving sensitivity when the feeding position is changed with x = 25 cm and y = 10 cm.

FIG. 28 is a diagram showing a change in reception sensitivity when the feeding position is changed with x = 30 cm and y = 10 cm.

FIG. 29 is a diagram showing a change in receiving sensitivity when the feeding position is changed with x = 10 cm and y = 3 cm.

FIG. 30 is a diagram showing a change in reception sensitivity when the feeding position is changed with x = 15 cm and y = 3 cm.

FIG. 31 is a diagram showing a change in reception sensitivity when the feeding position is changed with x = 20 cm and y = 3 cm.

FIG. 32 is a diagram showing a change in reception sensitivity when the feeding position is changed with x = 25 cm and y = 3 cm.

FIG. 33 is a diagram showing a change in reception sensitivity when the feeding position is changed with x = 30 cm and y = 3 cm.

FIG. 34 is a diagram showing a change in reception sensitivity when the feeding position is changed with x = 35 cm and y = 3 cm.

FIG. 35 is a diagram showing a change in receiving sensitivity when the feeding position is changed with x = 40 cm and y = 3 cm.

FIG. 36 is a diagram showing a change in receiving sensitivity when the feeding position is changed with x = 5 cm and y = 5 cm.

FIG. 37 is a diagram showing a change in receiving sensitivity when the feeding position is changed with x = 10 cm and y = 5 cm.

FIG. 38 is a diagram showing a change in receiving sensitivity when the feeding position is changed with x = 15 cm and y = 5 cm.

FIG. 39 is a diagram showing a change in receiving sensitivity when the feeding position is changed with x = 20 cm and y = 5 cm.

FIG. 40 is a diagram showing a change in receiving sensitivity when the feeding position is changed with x = 25 cm and y = 5 cm.

FIG. 41 is a diagram showing a change in reception sensitivity when the feeding position is changed with x = 30 cm and y = 5 cm.

FIG. 42 is a diagram showing a change in receiving sensitivity when the feeding position is changed with x = 35 cm and y = 5 cm.

FIG. 43 is a diagram showing a change in receiving sensitivity when the feeding position is changed with x = 40 cm and y = 5 cm.

44] In the antenna system of FIG. 1, y = 3
The figure which shows the UHF reception characteristic when changing the antenna width as cm.

45 is a diagram showing UHF reception characteristics (average reception sensitivity at an evaluation frequency) when the antenna width is changed in the antenna system of FIG.

46] In the antenna system of FIG. 1, y = 5
The figure which shows the UHF reception characteristic when changing the antenna width as cm.

47 is a diagram showing UHF reception characteristics (average reception sensitivity at an evaluation frequency) when the antenna width is changed in the antenna system of FIG.

48] In the antenna system of FIG. 1, y = 1
The figure which shows the UHF reception characteristic when changing the antenna width to 0 cm.

49 is a diagram showing UHF reception characteristics (average reception sensitivity at an evaluation frequency) when the antenna width is changed in the antenna system of FIG.

FIG. 50 is a view for explaining the shape of the antenna of the first modified example.

FIG. 51 is a diagram showing a vehicle windshield to which an antenna according to a first modification of the first embodiment is applied.

52] 88 to 110 of the antenna of the first modified example.
The figure explaining the receiving characteristic with respect to the electromagnetic wave of a MHz band.

[FIG. 53] 88 to 110 of the antenna of the first modified example
The figure explaining the receiving characteristic with respect to the electromagnetic wave of a MHz band.

FIG. 54 is a diagram showing the antennas 170 to 22 of the first modification.
The figure explaining the receiving characteristic to the electric wave of 5MHz band.

[FIG. 55] 170 to 22 of the antenna of the first modified example
The figure explaining the receiving characteristic to the electric wave of 5MHz band.

FIG. 56 is a view showing an antenna of the first modified example, 470 to 77;
The figure explaining the receiving characteristic with respect to the radio wave of 0MHz band.

57] 470 to 77 of the antenna of the first modified example.
The figure explaining the receiving characteristic with respect to the radio wave of 0MHz band.

FIG. 58 is a diagram illustrating the shape of the antenna of the second modified example.

FIG. 59 is a diagram showing a vehicle windshield to which an antenna according to a second modification of the first embodiment is applied.

FIG. 60 is a diagram showing a reception characteristic of the antenna according to the second modified example with respect to FM radio waves.

FIG. 61 is a diagram illustrating the configuration of an open-ended ground wire used in the antennas of the first to third embodiments of the present invention.

FIG. 62 is a diagram illustrating in detail a part of the open-ended ground wire of FIG. 61.

FIG. 63 is a diagram illustrating in detail a part of the open-ended ground wire of FIG. 61.

FIG. 64: Ordinary grounding type antenna ground plane anten
The figure explaining the body earth of na.

FIG. 65 is a view for explaining the principle of the open end type ground wire of the embodiment.

FIG. 66 is a view for explaining the principle of the open-ended ground wire of the embodiment.

FIG. 67 is a view for explaining the principle of the open-ended ground wire of the embodiment.

FIG. 68 is a diagram showing VSVR characteristics (ground wire length 10 cm) of the convex (T) formwork antenna of the first embodiment.

FIG. 69 is a diagram showing VSVR characteristics (ground wire length 20 cm) of the convex (T) formwork antenna of the first embodiment.

FIG. 70 is a diagram showing VSVR characteristics (ground wire length 30 cm) of the convex (T) formwork antenna of the first embodiment.

71 is a diagram showing VSVR characteristics (ground wire length 40 cm) of the convex (T) frame-shaped antenna of the first embodiment. FIG.

72 is a diagram showing VSVR characteristics (ground wire length 50 cm) of the convex (T) formwork antenna of the first embodiment. FIG.

FIG. 73 is a diagram showing VSVR characteristics (ground wire length 60 cm) of the convex (T) formwork antenna of the first embodiment.

FIG. 74 is a diagram showing a VSVR characteristic (using a ground plate) of the convex (T) formwork antenna of the first embodiment.

FIG. 75 is a diagram showing VSVR characteristics (without ground) of the convex (T) formwork antenna of the first embodiment.

FIG. 76 is a diagram showing VSVR characteristics (the ground is directly connected to the body) of the convex (T) formwork antenna of the first embodiment.

FIG. 77 is a diagram showing reception characteristics (88 to 110 MHz band) of the convex (T) formwork antenna according to the first embodiment.

FIG. 78 is a diagram showing reception characteristics (88 to 110 MHz band) of the convex (T) formwork antenna according to the first embodiment.

FIG. 79 is a reception characteristic of the convex (T) formwork antenna of the first embodiment (170 to 225 MHz band, ground length = 5);
FIG.

FIG. 80 is a reception characteristic of the convex (T) formwork antenna of the first embodiment (170 to 225 MHz band, ground length = 5).
FIG.

FIG. 81 is a reception characteristic (170 to 225 MHz band, ground length = 30 c of the convex (T) formwork antenna according to the first embodiment.
FIG.

FIG. 82 is a reception characteristic (170 to 225 MHz band, ground length = 30 c of the convex (T) formwork antenna of the first embodiment.
FIG.

[FIG. 83] Reception characteristics of the convex (T) formwork antenna of the first embodiment (470 to 770 MHz band, ground length = 20 c)
FIG.

FIG. 84 is a reception characteristic of the convex (T) formwork antenna according to the first embodiment (470 to 770 MHz band, ground length = 20 c).
FIG.

FIG. 85 is a diagram showing reception characteristics (170 to 225 MHz band, ground length = 30 cm) of the long-frame antenna according to the first embodiment.

FIG. 86 is a diagram showing reception characteristics (170 to 225 MHz band, ground length = 30 cm) of the long-frame antenna according to the first embodiment.

FIG. 87 is a diagram showing reception characteristics (470 to 770 MHz band, ground length = 10 cm) of the long-frame antenna according to the first embodiment.

FIG. 88 is a diagram showing reception characteristics (470 to 770 MHz band, ground length = 10 cm) of the long-frame antenna according to the first embodiment.

FIG. 89 is a view showing a side glass of a vehicle to which the glass antenna (open end type ground wire attached) of the second embodiment of the present invention is applied.

FIG. 90 is a view showing a side glass of a vehicle to which the glass antenna (ground plate attached) of the second embodiment of the invention is applied.

FIG. 91 is a VSWR (without ground) characteristic diagram of the antenna of the second embodiment.

FIG. 92 is a VSWR (ground wire length = 10 cm) characteristic diagram of the antenna of the second embodiment.

FIG. 93 is a VSWR (ground wire length = 20 cm) characteristic diagram of the antenna of the second embodiment.

FIG. 94 is a VSWR (ground wire length = 30 cm) characteristic diagram of the antenna of the second embodiment.

FIG. 95 is a VSWR (ground wire length = 40 cm) characteristic diagram of the antenna of the second embodiment.

96 is a VSWR (ground wire length = 50 cm) characteristic diagram of the antenna of the second embodiment. FIG.

97 is a VSWR (ground wire length = 60 cm) characteristic diagram of the antenna of the second embodiment. FIG.

98 is a VSWR (ground wire length = 70 cm) characteristic diagram of the antenna of the second embodiment. FIG.

FIG. 99 is a VSWR (ground wire length = 80 cm) characteristic diagram of the antenna of the second embodiment.

100 is a VSWR (ground wire length = 90 cm) characteristic diagram of the antenna of the second embodiment. FIG.

101 is a VSWR (ground wire length = 100 cm) characteristic diagram of the antenna of the second embodiment. FIG.

102 is a VSWR (ground wire length = 110 cm) characteristic diagram of the antenna of the second embodiment. FIG.

103 is a VSWR (ground plate attachment) characteristic diagram of the antenna of the second embodiment. FIG.

FIG. 104 is a VSWR (direct to body) characteristic diagram of the antenna of the second embodiment.

FIG. 105 is a diagram showing reception characteristics of the antenna of the second embodiment.

FIG. 106 is a diagram showing reception characteristics of the antenna of the second embodiment.

FIG. 107 is a diagram illustrating a rear window glass of a vehicle to which an antenna according to a third embodiment of the present invention is attached.

FIG. 108 is a view showing a mounting state when the antenna according to the first embodiment is mounted on a windshield using an open end type ground wire.

FIG. 109 is a view for explaining another form of the open-ended ground wire applicable to the antennas according to the first to third embodiments of the present invention.

FIG. 110A is a diagram showing another example in which the ground of FIG. 109 is applied to the windshield.

110B is a diagram showing yet another example in which the ground of FIG. 109 is applied to a windshield.

111A is a diagram showing another example in which the ground of FIG. 109 is applied to the rear glass. FIG.

111B is a view showing still another example in which the ground shown in FIG. 109 is applied to the rear glass.

Claims (33)

[Claims] 1. A grounding structure, which is provided separately from an electric conductor that functions as a theoretical ground separately from this conductor, wherein one end is connected to the ground line side of the antenna feeder line and the other end is opened. And a long ground portion having a predetermined length, the long ground portion being insulated from the electrical conductor from the one end to the other end and provided along the conductor. A grounding structure characterized by being provided independently of parts such as vehicles to which the structure is attached. 2. The feeder wire includes a shield wire having a coaxial structure, and the long ground portion is a part of the shield wire pulled out by the predetermined length. Earth structure as described. 3. The ground structure according to claim 1, wherein the electric conductor is a vehicle body. 4. The long earth portion is provided with a wavelength λ of a received radio wave.
4. The ground structure according to claim 1, wherein the length is set to λ / 4. 5. The long earth portion is provided along a predetermined planar electric conductor via a predetermined insulating layer having a line shortening rate δ, and its length is set to δ · λ / 4. The ground structure according to any one of claims 1 to 4, wherein the ground structure is formed. 6. The ground structure according to claim 1, wherein the ground structure is provided on a vehicle, and the ground portion is extended to a windshield of the vehicle. 7. The earth structure according to claim 6, wherein the length of the long earth portion is set to α · λ / 4 where α is a line shortening rate of the windshield. . 8. The earth structure according to claim 1, wherein the long earth portion is bundled while being insulated from the feeder wire. 9. An in-vehicle antenna device provided at a position surrounding a vehicle verification seal on an upper part of a windshield of a vehicle, wherein the in-vehicle antenna device is provided above the antenna structure and substantially functions as a feeding point. In order to transmit a reception signal from the frame-shaped antenna wire, which has a substantially frame shape, and which is extended on the glass so as to surround the vehicle verification seal in the hollow portion, to a receiver or the like. And a grounding part having one end connected to the grounding wire side of the feeder wire and the other end being open, the maximum horizontal length x and the maximum vertical length y of the frame-shaped antenna wire. Is set to satisfy y ≦ α · λ / 4 x ≦ 60 cm−y, where α is the line shortening rate of the windshield, and the frame antenna has a predetermined distance from the upper end of the view range of the windshield. Below the distance An in-vehicle antenna device characterized in that the width of a certain portion is set to 6.6 cm or less. 10. A power feeding portion that substantially functions as a power feeding point, and a hollow substantially circular shape that is connected to the power feeding portion and has an inner diameter of 7 cm or more, and the glass is surrounded by the regular inspection seal. A round hollow antenna wire extended above, a feeder wire for transmitting a received signal from the round hollow antenna wire to a receiver, etc., one end of which is connected to the ground wire side of the feeder wire and the other end And a maximum length x in the horizontal direction of the round hollow antenna wire and a maximum length y in the vertical direction, the line shortening rate of the windshield is α.
Then, the in-vehicle antenna device is set so as to satisfy y ≦ α · λ / 4 x ≦ 60 cm-y. 11. A power feeding portion which substantially functions as a power feeding point, which is provided at an upper end portion of a windshield of a vehicle, and which has a hollow substantially rectangular shape and is connected to the power feeding portion, and has an upper portion on the glass. A rectangular hollow antenna wire extended to, a feeder wire for transmitting a received signal from the rectangular hollow antenna wire to a receiver, etc., one end is connected to the ground wire side of the feeder wire, the other end is And a maximum length x in the vertical direction of the rectangular hollow antenna wire is set so as to satisfy 5 cm ≦ x ≦ 40 cm 3 cm ≦ y ≦ 10 cm. An in-vehicle antenna device characterized by the above. 12. A power feeding portion substantially functioning as a power feeding point, a frame-shaped antenna wire connected to the power feeding portion, having a hollow frame shape, and extending on a side glass of a vehicle side portion, The frame-shaped antenna comprises: a feeder line for transmitting a received signal from the frame-shaped antenna line to a receiver or the like; and a grounding part having one end connected to the ground line side of the feeder line and the other end open. An in-vehicle antenna device, wherein a maximum horizontal length x and a maximum vertical length y of the line are set so as to satisfy x ≦ 30 cm 20 cm ≦ y ≦ 40 cm x + y ≦ 60 cm. 13. An in-vehicle antenna device provided on a rear window glass at a rear portion of a vehicle provided with a defogger, comprising: a power feeding section that substantially functions as a power feeding point; A frame-shaped antenna wire having a frame shape and extended on the windshield, a feeder wire for transmitting a reception signal from the frame-shaped antenna wire to a receiver, and the ground wire side of the feeder wire. A ground portion having one end connected to the ground portion and the other end opened, and a length L provided at a substantially central portion of the defogger in the vehicle width direction.
And a maximum length x in the horizontal direction of the frame-shaped antenna wire and a maximum length y in the vertical direction, where the line shortening rate between the antenna wire and the vertical conductor is ω, An in-vehicle antenna device characterized in that x≤30 cm, 20 cm≤y + ωL≤40 cm x + y + ωL≤60 cm. 14. The ground structure according to claim 10, wherein the ground portion is held by the feeder wire. 15. The in-vehicle antenna device according to claim 10, wherein the grounding portion is arranged along a body of the vehicle. 16. The ground portion is provided with an insulating layer between the body and the body, and the length of the ground portion is λ where the wavelength of the received radio wave is λ and δ is the line shortening rate due to the insulating layer. , Δ · λ / 4, and the vehicle-mounted antenna device according to any one of claims 10 to 15. 17. A power feeding portion that substantially functions as a power feeding point, and a hollow, substantially circular shape that is connected to the power feeding portion and has an inner diameter of 7 cm or more, and the glass is surrounded by the regular inspection seal. A round hollow antenna wire extended above, a feeder wire for transmitting a received signal from the round hollow antenna wire to a receiver, etc., one end of which is connected to the ground wire side of the feeder wire and the other end And a maximum length x in the horizontal direction of the round hollow antenna wire and a maximum length y in the vertical direction, the line shortening rate of the windshield is α.
Then, 7 cm ≤ x ≤ 30 cm, y ≤ α · λ / 4 7 cm ≤ y ≤ 10 cm x + y ≤ 60 cm. 18. A power feeding portion substantially functioning as a power feeding point, a rectangular hollow antenna wire connected to the power feeding portion, having a hollow substantially rectangular shape, and extending to an upper portion of the glass. A feeder line for transmitting a received signal from the rectangular hollow antenna line to a receiver and the like, and a grounding part having one end connected to the ground line side of the feeder line and the other end being open, the rectangle The maximum length x in the horizontal direction and the maximum length y in the vertical direction of the hollow antenna wire are set as follows: x ≧ 30 cm, y ≦ α · λ / 4 7 cm ≦ y ≦ 10 cm x + y ≦ 60 cm Antenna device. 19. The vehicle-mounted antenna device according to claim 18, wherein the pattern includes a plurality of separate and independent antenna lines, and these antenna lines form a diversity system. 20. A ground structure provided separately from an electric conductor functioning as a ground, having a first end and a second end, the first end being an antenna feeder wire. Has a ground wire which is connected to one end of the ground wire and whose second end is released. The ground wire portion from the first end to the second end is the electric conductor. An earth structure, which is insulated and provided along the conductor, and which is attached to the vehicle side independently of a harness arranged in the vehicle. 21. The length of the ground wire portion is set corresponding to the wavelength of the received radio wave.
Ground structure described in. 22. The length of the ground wire portion is set such that the impedance with respect to the first end portion is substantially zero when the ground wire portion is viewed as a transmission line. 22. The ground structure according to claim 21. 23. The length of the ground wire portion from the first end portion to the second end portion is set to approximately λ / 4 with respect to the wavelength λ of the received radio wave. The ground structure according to claim 22. 24. The ground wire portion is provided along the electric conductor via a predetermined insulating layer having a line shortening rate δ, and its length is set to δ · λ / 4. 23. The ground structure according to claim 22, wherein: 25. The ground structure according to claim 22, wherein the ground structure is provided on a vehicle, and the ground wire portion is extended to a windshield of the vehicle. 26. When the line shortening rate of the windshield is α, the length of the earth wire portion is approximately α · λ / 4.
The ground structure according to claim 25, wherein the ground structure is set to. 27. When the feeder line has a shielded wire having a coaxial structure, the first end of the ground wire portion is connected to a part of the shielded wire. Ground structure described in. 28. The ground structure according to claim 20, wherein the electrical conductor is a metal portion of a vehicle body. 29. The ground structure according to claim 20, wherein the ground structure is provided on a vehicle, and the ground wire portion is attached to a windshield of the vehicle. 30. The ground structure according to claim 29, wherein the ground wire portion is coated with insulation. 31. The ground structure according to claim 20, wherein the ground wire portion is bundled while being insulated from the feeder wire. . 32. The ground structure according to claim 20, wherein the ground wire portion is bendable. 33. The first end of the ground wire portion comprises:
The ground structure according to claim 20, wherein the ground structure is arranged in the vicinity of the electrical conductor.