JP3729414B2 - Glass antenna and antenna - Google Patents

Description

  The present invention relates to an antenna provided on a front window of an automobile.

  Since the glass window for a vehicle restricts the driver's field of view, various laws and regulations are imposed on the glass antenna provided in the window in order to ensure the field of view. Therefore, the glass antenna is not allowed to be freely designed in size, width and length, and has certain limitations.

  Since glass antennas are disadvantageous in sensitivity as compared to rod-type antennas, the above laws and regulations greatly affect antenna performance. Although it is not particularly conscious of the laws and regulations, the prior art relating to a glass antenna with a devised shape includes, for example, a vehicle antenna device disclosed in Japanese Patent Publication No. 3-74845 and a roof glass antenna disclosed in Japanese Patent Application Laid-Open No. Hei 3-1703. And the paper “Broadband and omnidirectional disk monopole antenna” (co-authored by Satoshi Ito and Seiichi Seki).

  The vehicle antenna device of Japanese Patent Publication No. 3-74845 pays attention to the relationship between the metal pillar and the antenna, and sets the pillar length to λ / 2 or less and the antenna length to λ / 4 or less. This glass antenna is basically a monopole antenna because of its interest in the relationship with the pillar, and thus there is no mention of the width direction. Therefore, at the current vehicle size, at most FM. It can be applied only to the frequency band.

  The roof glass antenna disclosed in JP-A-3-1703 is also set as a loop antenna having a length of 200 to 1500 mm, and further, the conductive wire to the feeding point is set substantially parallel to the center line in the longitudinal axis direction of the vehicle. It is what. However, this prior art also has an interest in the overall length of the loop antenna, but is not interested in the relationship between the vertical and width directions of the antenna. Must repeat trial and error by changing the vertical and horizontal lengths in the range of 200 to 1500 mm.

  Further, the disk monopole antenna shown in the above paper has a wide band by the circular shape of the disk. Therefore, when this antenna is applied to a glass antenna for a vehicle, the field of view is hindered. There is a dislike that the target performance cannot be achieved if the size is reduced to ensure visibility. Therefore, the present invention has been made in view of the problems of the prior art, and an object thereof is to provide a glass antenna and an antenna that ensure high visibility while ensuring visibility.

According to the present invention, there is provided a glass antenna spread on a front windshield of an automobile, the pattern of the glass antenna from a feeding portion provided on the front windshield and substantially functioning as a feeding point. Is set to y ≦ λ / 4 · α, where the wavelength of the reception frequency is λ and the glass shortening rate is α, and the horizontal length x of the glass antenna pattern is The relationship with the maximum length y in the vertical direction is set to x + y ≦ 60 cm, and the pattern has a shape surrounding the vehicle verification seal or the periodic inspection seal and is disposed at a position surrounding the vehicle verification seal or the periodic inspection seal. glass antenna is provided, wherein the to be.
In this glass antenna, the length in the vertical direction corresponds to the target reception frequency band, and the length in the horizontal direction corresponds to the expansion of the band. The relationship between x and y is adjusted so that if one is increased with the upper limit being 60 cm, the other is decreased. According to this glass antenna, since the adjustment is easy, it is possible to easily clear conditions such as securing the field of view applied on the front window glass, and to maintain high-performance reception characteristics. Further, since the pattern has a shape surrounding the vehicle verification seal or the periodic inspection seal and is disposed at a position surrounding the vehicle verification seal or the periodic inspection seal, the pattern can be placed in the deployment position without hiding the vehicle verification seal or the periodic inspection seal. The degree of freedom can be given, and when the seal is replaced, the spread pattern is not damaged.

Further, according to the present invention, there is provided an antenna that is spread on a front window of an automobile, and is provided on an upper portion of the front window, and is a vertical portion of the antenna pattern from a feeding portion that substantially functions as a feeding point. The maximum direction length y is set to y ≦ λ / 4 · α ′, where λ is the wavelength of the reception frequency and α ′ is the shortening rate of the front window material, and the maximum horizontal length of the antenna pattern The relationship between the length x and the maximum longitudinal length y is set to x + y ≦ 100 cm × α ′, and the pattern has a shape surrounding the vehicle verification seal or the periodic inspection seal, and the vehicle verification seal or the periodic interval An antenna is provided that is disposed at a position surrounding the inspection seal .
In this antenna, the length in the vertical direction corresponds to the target reception frequency band, and the length in the horizontal direction corresponds to the spread of the band. The relationship between x and y is adjusted so that if one is increased with the upper limit being 100 cm, the other is decreased. According to this antenna, since adjustment is easy, it is possible to easily clear conditions such as securing the field of view applied on the front window, and to maintain high-performance reception characteristics. Further, since the pattern has a shape surrounding the vehicle verification seal or the periodic inspection seal and is disposed at a position surrounding the vehicle verification seal or the periodic inspection seal, the pattern can be placed in the deployment position without hiding the vehicle verification seal or the periodic inspection seal. The degree of freedom can be given, and when the seal is replaced, the spread pattern is not damaged.

  As described above, according to the present invention, it is possible to ensure high performance while ensuring visibility.

  Hereinafter, an embodiment in which a glass antenna of the present invention is applied to a window glass of an automobile will be described with reference to the drawings. In the embodiment described below, a glass antenna (first embodiment) applied to a front window glass, a glass antenna (second embodiment) applied to a rear window glass, and a glass antenna (third embodiment) applied to a side glass. Form).

  For each of the glass antennas of these embodiments, it is possible to achieve a problem specific to the position of the installed glass (ensure the front view with the windshield antenna and eliminate the influence of the defogger with the rear glass antenna). In addition to being described, these modifications (a grounded antenna using a ground plate and a grounded antenna using a ground wire) will also be described.

<First Embodiment>
FIG. 1 shows a windshield window 100 to which a glass antenna according to a first embodiment of the present invention is applied as seen from the front outside of a 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 inside the vehicle. The antenna 10 is mainly an antenna for receiving FM radio waves and TV radio waves. The antenna 10 has a vertically long loop rectangular shape shown in FIG. 3 and has a horizontal (vehicle width direction) length of x1 (for example, 10 cm as an example). It has a direction length y1 (for example, 20 cm as an example). The antenna 20 is a horizontally long loop rectangular antenna as shown in FIG. The antenna 30 provided on the rightmost side of the window 100 is a circular loop antenna as shown in FIG. These three antennas (10, 20, 30) constitute a diversity antenna system.

The horizontal length x and the vertical length y of these three antennas have the following relationship. That is, if 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)
It is. The meaning of equation (2) (the sum of x and y must not exceed 60 cm) will be described later. By setting the antenna size according to equations (1) and (2), appropriate reception sensitivity is ensured. it can.

When the antenna 10 is provided on the windshield, the antenna 10 is provided so as to be accommodated in a belt-like portion provided with a width of 66 mm symmetrical to the center line of the windshield so as not to obstruct the driver's front vision.
Further, when the antennas 20 and 30 are provided above (or below) the window, the lateral width of the antenna is determined as follows. That is, when the front window glass is attached to the vehicle body, there are ceramic coats and moldings around it. There is no legal restriction on the width of the glass antenna in the area along the periphery of the window up to 10 cm from the upper end of the portion where the field of view is not hindered by the coat or the mall. Therefore, the size of the antenna in the width direction can be determined according to the target frequency band and reception sensitivity regardless of the regulation. However, when the length of the antenna in the vertical direction exceeds 10 cm downward from the upper end, the antenna is placed within the range of 66 mm in the width of the glass center. That is, it is preferable that the width from the lower end portion of the antenna to the position of the antenna portion 10 cm from the upper end is 66 mm.

  When an antenna is installed below the window glass, the width of the antenna is not restricted from the lower end of the portion where the above-mentioned view of the window is not obstructed up to a position of 10 cm, but at the position exceeding 10 cm, the width is the same. Must not exceed 66mm. Therefore, it is preferable that the width from the upper end portion of the antenna to the position of the 10 cm antenna portion measured from the lower end is 66 mm.

For the antenna 20 (FIG. 4), x and y are set within a range satisfying the above expressions (1) and (2), and y2 is set within 100 mm so as not to obstruct the driver's view. To do. For example, x ₂ = 15 cm and y ₂ = 65 mm. Similarly, the diameter x ₃ = y ₃ of the antenna 30 (FIG. 5) is set within 100 mm (for example, 80 mm as an example). Further, for the antenna 10, the length L _y in the vertical direction is set within 100 mm, and the length L _x in the horizontal direction is set within 66 mm (for example, just 66 mm). If it does in this way, all three antennas 10, 20, and 30 will be installed so that a driver | operator's visual field may not become obstructed. The antennas 10, 20, and 30 have a constant line width.

When the antenna 10 is installed at the approximate center of the window 100, a “vehicle verification” seal is usually affixed to this position. The car verification seal has a size of 70 mm × 70 mm. As shown in FIG. 3, when the dimension inside the opening is x ₁ 'L _y ', x ₁ '> 70 mm (3)
L _y ′> 70 mm (4)
The vehicle verification sticker will fit within the loop of the antenna 10. It is obliged to replace the car verification seal regularly, but if the formulas (3) and (4) are satisfied, the conductor of the antenna 10 will not overlap the position where the car verification seal is pasted, and the seal will be replaced. In doing so, the antenna wire is not unnecessarily peeled off.

The right side (viewed from the outside) of the window 100 is also a place where a regular inspection seal is pasted. This seal has a circular shape. Therefore, if the dimensions inside the opening are x ₃ ′, y ₃ ′ and the size of this seal is S, as shown in FIG.
x ₃ '= y ₃ '> S
Then, the replacement of the periodic inspection seal does not inadvertently peel off the conductor of the antenna 30. When an antenna pattern is actually set on a vehicle on which a vehicle verification seal and a periodic inspection seal are pasted, the result is as shown in FIG.

<Antenna Spread> ... 1st Embodiment Since the glass antenna of 1st Embodiment is provided in a windshield, it is preferable to attach easily. For this purpose, the antennas 10, 20, and 30 are peeled off from the adhesive seal and attached to the glass window.
There are various methods for spreading the three antennas on the glass window surface shown in FIGS. If the shape and the spreading position are fixed, a thin plate-like conducting wire is attached by a well-known method in a factory. In this case, it is possible to set the wiring of the conducting wire for power feeding at the best position that does not hinder the field of view. Further, the ground wire can be connected to the vehicle body so that the ground resistance is the smallest.

  Whether or not the antenna is set on the windshield as in the first embodiment largely depends on the driver's preference. Therefore, in the first embodiment, a method in which a normal driver simply spreads an antenna wire on a glass window after factory shipment is adopted. For that purpose, it is preferable to provide the antenna wire with a seal coated with an adhesive layer.

  FIG. 6 shows the cross-sectional shape of such an antenna when such an antenna is commercially available. That is, when the antennas 10 to 30 are commercially available, as shown in FIG. 6, an adhesive layer 62 is formed on the base paper layer 63, and between the adhesive layer 62 and the antenna conductive wire layer 61. The adhesive layer is formed, and the adhesive layer 62 and the antenna conductive wire layer 61 are fixed by the adhesive layer. A protective film 60 is formed on the antenna conducting wire. The protective film 60 is formed only on the surface of the conducting wire to prevent oxidation of the conducting wire and protect 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 adhesive layer 62 exposed to a desired glassy position. In this case, it is preferable to stick to the inside of the window in consideration of weather resistance.

<Grounding Method>... First Embodiment All three glass antennas of the first embodiment are antennas that require grounding. When a general user installs an antenna, how to attach the ground becomes a problem. This is because an iron plate constituting an automobile body is usually protected with a non-conductive paint. Therefore, in the first embodiment, it is proposed to insert the ground plate 40 as shown in FIG. 7 by utilizing a slight gap between the iron plate of the automobile roof and the ceiling cushion material. . As shown in FIG. 8, the ground plate 40 is inserted between the iron plate of the automobile roof and the ceiling cushion material. Although only the antenna 10 is illustrated in FIG. 8 for convenience of explanation, the ground plate 40 is connected to the antenna 10 via the adapter 50.

  FIG. 9 shows the configuration of the adapter 50. The adapter 50 includes a case 51, a low impedance wire 54, a conductive clip 52 provided at the tip of the wire 54, a shield wire 53, and a coaxial connector 55. The antenna connection pieces (11, 21, 31) are connected to the adapter. The core wire of the connector 55 is connected to an antenna tuner or the like. Further, the shield wire of the shield wire 53, the wire 54, and the clip 52 are electrically (directly) connected. The clip 52 is connected to the tongue piece 41 of the ground plate 40.

  FIG. 10 shows the configuration of the ground plate 40. That is, the ground plate 40 is composed of the magnet layer 43 and the conductive metal layer 42. When the ground plate 40 is inserted between the roof trim and the roof panel as shown in FIG. 8 and the clip 52 is connected to the tongue piece 41, the ground plate 40 and the metal of the roof are connected as shown in FIG. Touch. Since there is a gap 46 (air layer or paint layer) between the metal layer 42 of the ground plate 40 and the metal of the roof, the ground plate 40 and the vehicle body are capacitively coupled. In the present embodiment, the area of the ground plate 40 is set so that the coupling capacitance is 10 pF. This is because the capacity 10 pF is a capacity at which the antenna 10 exhibits practical sensitivity in the FM radio wave band. Moreover, as shown in FIG. 12, you may attach to a roof with a magnet directly.

  Depending on the type of vehicle, the ground plate may not be inserted. In such a case, it is more cost effective to directly connect the ground wire of the adapter to the vehicle body because there is no need to use a ground plate. FIG. 13 shows the structure of a clip for that purpose. A capacitor of 10 pF can be obtained by coupling the clip of FIG. 13 to, for example, the flanger portion of the vehicle body.

<Relationship Between Dimension x and Dimension y> First Embodiment FIGS. 14 to 29 show the antenna 10 as an example, the height (= y) of the antenna 10 is set to a certain value, and the width x varies. The average reception sensitivity with respect to the frequency of the received radio wave in the VHF band of FM radio and TV is shown.
For example, FIG. 14 shows the reception sensitivity when the height y is fixed to 5 cm and the width x is set to 0.5 cm by the curve I, and the reception sensitivity when the width x is set to 2 cm and the curve II. The reception sensitivity when the width x is set to 5 cm is represented by the curve III, the reception sensitivity when the width x is set to 10 cm is represented by the curve IV, and the reception sensitivity when the width x is set to 15 cm is represented by the curve V. And the reception sensitivity when the width x is set to 25 cm is represented by the curve VI, the reception sensitivity when the width x is set to 30 cm is represented by the curve VII, and the reception sensitivity when the width x is set to 40 cm is represented by the curve VIII. The reception sensitivity when the width x is set to 50 cm is represented by the curve VIIII, and the reception sensitivity when the width x is set to 60 cm is represented by the curve X. FIG. 15 shows an average of the curves representing the ten test results within the evaluation frequency range.

The average reception sensitivity table of FIG. 17 corresponds to the graph of FIG. 16 (y = 10 cm).
The table of average reception sensitivity in FIG. 19 corresponds to the graph in FIG. 18 (y = 15 cm).
The average reception sensitivity table of FIG. 21 corresponds to the graph of FIG. 20 (y = 20 cm).

The table of average reception sensitivity in FIG. 23 corresponds to the graph in FIG. 22 (y = 25 cm).
The average reception sensitivity table of FIG. 25 corresponds to the graph of FIG. 24 (y = 30 cm).
The table of average reception sensitivity in FIG. 27 corresponds to the graph in FIG. 26 (y = 35 cm).

  The table of average reception sensitivity in FIG. 29 corresponds to the graph in FIG. 28 (y = 40 cm).

These figures show that the height y of the antenna 10 (or the antenna 20 or 30) is up to about 40 cm, generally a maximum of λ / 4 · α.
Practical sensitivity can be obtained up to the length of.
14 to 29, the reception sensitivity is low when x≈y, but the reception sensitivity is relatively high when x> y or x <y. That is, when the length in the vertical direction, that is, the height y is relatively shorter than the horizontal length x in the range of 0 to λ / 4 · α (y <x), it is in the high frequency region and the width. Good reception sensitivity can be obtained in a wide range of x. On the other hand, when y is relatively long in the range of 0 to λ / 4 · α (y> x), good reception sensitivity is obtained in a relatively low frequency region and in a wide width x range. further,
8cm ≦ y ≦ 40cm
x ≦ 30cm
In this range, it can be seen that ideal reception sensitivity can be obtained in the frequency band centered on the VHF band of TV, and that the band where the reception sensitivity can be secured is changed by changing the width x. Furthermore, when the sum of x and y exceeds 60 cm, it can be seen that the reception sensitivity is lowered.

In addition, considering the legal and regulatory scope shown in FIG.
7cm ≦ x ≦ 30cm,
7cm ≦ y ≦ 10cm
Is more preferable.

FIGS. 51 to 56 show that when the received radio wave is in the UHF frequency band, the reception sensitivity can be −20 dB if the antenna width is 40 cm or less. 51 and 52 show the results when the antenna width length x is changed variously while fixing y = 3 cm. That is,
5 cm = curve I, 10 cm = curve II, 15 cm = curve III, 20 cm = curve IV,
25 cm = curve V, 30 cm = curve VI, 35 cm = curve VII, 40 cm = curve VIII
It is. 53 and 54 show the case when y = 5 cm, and FIGS. 55 and 56 show the case when y = 10 cm.

If α is 0.6 in the above-described equation (1), equation (1) indicates that y is preferably 10 cm or less (450 Mhz or more) in order to receive the UHF frequency band. As an antenna installed on the front windshield of a vehicle, it can be conveniently installed in an area that does not obstruct the driver's field of view, that is, an area up to 10 cm inward from the end of the window. Therefore, as an antenna suitable for the UHF frequency band,
5cm ≦ x ≦ 40cm
y ≦ 10cm
Is preferably set as the lower limit of y in order to ensure reception sensitivity,
3cm ≦ y ≦ 10cm
It is good to do.

FIG. 30 summarizes the results shown in FIGS. 14 to 29 and FIGS. 51 to 56 and represents the relationship between x and y as a graph. In the figure, the line segment AB is a linear straight line x + y = 60 cm.
It is. This indicates that the critical value of the sum of width x and height y for ensuring reception sensitivity is 60 cm as described above, and is an area surrounded by line segment AB, x-axis, and y-axis. Is
x + y ≦ 60cm
It is expressed.

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

<Influence of Feed Point> First Embodiment FIGS. 31 to 50 show how the reception sensitivity changes depending on whether the feed point is located at the center or the end of the conductor side of the antenna. Is shown. In each graph, the solid line indicates that the feeding point is at the end, and the wavy line indicates that the feeding point is at the center. The numbers in the graph indicate the average sensitivity within the evaluation frequency range.

  In addition, the feeding point of the antenna in the present invention refers to a point closest to the receiver in a portion acting as an antenna. In the frame-type antennas of all the embodiments of the present invention, what acts as an antenna is a junction between the frame-shaped portion and the leader line to the feeder, and this junction is defined as a feeding point in the embodiment. Is done.

Although the antenna system of the first embodiment achieves the target of −20 dB, especially when the feed point is installed at the end, the sensitivity is improved in the UHF band in the antenna set as x> y. I can see that
<Dimension Settings> ... First Embodiment As described above, a method for designing the dimensions of an antenna provided on the front window of an actual vehicle while satisfying both the driver's view securing requirements and the reception sensitivity and widening of the band. explain.

First, the vertical dimension y is determined.
The vertical length of the antenna is substantially determined by λ / 4 · α, where λ is the wavelength of the reception frequency and α is the glass shortening rate.
In the first embodiment, the antennas 10, 20, and 30 in FIG. 1 are set to 20 cm targeting 225 MHz, 8 cm targeting 562.5 MHz, and 6.5 cm targeting 692.3 MHz, respectively, with α = 0.6. (FIGS. 3 to 5).

Subsequently, the horizontal dimension x is set.
As described above, the horizontal dimension affects the spread of the band where the reception sensitivity can be secured. As the trend widens, the wider the band, the wider the band, but if it becomes too wide, the reception sensitivity decreases. The limit is the length that the sum of the vertical dimension y and the horizontal dimension x is 60 cm (x + y = 60).

  TV radio waves have a wide frequency band (VHF 90 MHz to UHF 770 MHz) and cannot be covered with a single antenna. Therefore, of the three antennas 10, 20, and 30, the antenna 10 mainly has a 90 V to 230 MHz TV VHF band, the antenna 20 has a 500 MHz to 770 MHz, and the antenna 30 has a main TV UHF band of 470 MHz to 600 MHz. The lateral width is set so as to cover each, and the lateral dimensions are 10 cm, 15 cm, and 8 cm as shown in FIGS. In addition, the antenna 20 and the antenna 30 overlap the bands that can be covered, and the diversity system formed by each antenna is effective.

Now, 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 portion needs to be suppressed to 6.6 cm or less in order to ensure the driver's view.
The antenna 30 has a size of 8 cm × 8 cm and surrounds the periodic inspection seal, and the reception band is determined by the maximum values of the vertical dimension and the horizontal dimension, and does not depend on the shape. Install in the surrounding position.

  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 window's field of view as described above except for the central part of the window. An antenna that receives a relatively low frequency (VHF) having a long vertical dimension is installed in the center of the window, and an antenna that receives a high frequency having a short vertical dimension is installed in the other part.

<First Modification of First Embodiment>
The antenna 10 provided on the windshield of the first embodiment has a vertically long convex shape as shown in FIG. 3 mainly for reception in the VHF frequency band. A first modification described below is an antenna 110 having a horizontally long concave shape as shown in FIG. 57 for the purpose of receiving radio waves in the same frequency band. That is, the dimensions of this antenna 110 are
x ₁ = 22 cm,
y ₁ = 9 cm
L _y = 8cm
It is said.

  As shown in FIG. 58, the antenna 110 of this modification is effective for a vehicle in which the rearview mirror 101 is attached to the base 100 provided directly on the front window glass. The length in the vertical direction was set to 9 cm, which is 7 cm or more and less than 10 cm, for the same reason as in the first embodiment (enclosing the vehicle verification and ensuring visibility). The concave notch 102 is provided to prevent the antenna line from interfering with the base 100.

The basic design philosophy regarding the dimensions of the antenna of the first modification is set to a range of 7 cm to 10 cm with respect to the longitudinal length y because it is required to surround the field of view and vehicle verification. If y is set to y = 7 to 10 cm, the frequency band λ adapted to this length is defined as α when the shortening rate of the glass is α.
λ = (4y / α)
This wavelength corresponds to a TV wave in the UHF band. The antenna of the first modified example is a kind of frame-shaped antenna, and has the property that the frequency band can be widened by increasing the horizontal length x as a characteristic of the frame-shaped antenna. Therefore, in the first modification, the horizontal band x is set to be sufficiently long, for example, 22 cm, and the reception band is successfully extended to the VHF band.

  59 to 64 show the radio waves (horizontal deviation) in the FM frequency band (88 to 110 MHz), the VHF frequency band (170 to 225 MHz), and the UHF frequency band (470 to 770 MHz), respectively, of the concave antenna according to the first modification. (Wave) in FIG. 59, FIG. 61, and FIG. As a comparison object, the characteristics of the antenna 20 (that is, a horizontally long frame shape) of the first embodiment (also curve II) and the characteristics of the antenna 30 (that is, a round frame shape) of the first embodiment (also curve III). ) Is shown in the figure. The concave antenna of the first modification shows antenna sensitivity that can be practically used as -13.7 to -16.2 dB (see FIGS. 60, 62, and 64) in each frequency band.

In the experiments of FIGS. 59 to 64, “open type ground wire” described later was used as the ground of each antenna. The length of the “open ground wire” of the antenna 20 is 30 cm, and the length of the ground wire of the antenna 30 is 15 cm.
<Second Modification of First Embodiment>
This second modification is an antenna 120 intended for the FM band. In the first embodiment, the antenna 10 is used as an antenna for TV and FM. However, in the second modification, radio FM radio waves and VICS (Vehicle Information & Communication System) radio waves are received with diversity. It is aimed.

The shape of the antenna 120 of the second modification is shown in FIG. In order to improve the reception sensitivity of the FM band, it is longer (35 cm) in the lateral direction than the first modification (y = 22 cm). As shown in FIG. 66, a diversity system is configured by providing two antennas 120.
The design concept of the second modified example is basically the same as that of the first modified example. However, in order to make FM reception the main purpose, the lateral width x is expressed by the equations (1) and (2) (further, x = 7 to 10 cm), which is as long as possible.

As shown in FIG. 66, if the antenna 120 does not interfere with the base 100, the notch is unnecessary in the second modification.
FIG. 67 shows reception sensitivity characteristics in the FM radio wave region of the antenna 120 of the second modification. At this time, the average sensitivity Pw-AV is -10.5 dB, which indicates that the antenna has sufficient performance as a VICS antenna.

In addition, the preferable range of the 2nd modification in consideration of the legal regulation shown in FIG.
x ≧ 30 cm,
7cm ≦ y ≦ 10cm
It becomes.
<Improvement of ground plate>
Since the ground plate of 1st Embodiment employ | adopts the method clamped with a clip, a ground plate and a clip are easy to remove | deviate. The ground plate shown in FIG. 68 improves on this shortcoming, and the ground lead wire and the ground plate are welded.

The ground plate shown in FIG. 68 is applicable not only to the first embodiment, but also to the ground of the antennas of the second and third embodiments to be described below, and to all types of grounded antennas.
<Open end type ground wire> Common to the first to third embodiments All the antennas of the first embodiment use the ground plate of the shape shown in FIG. 7 or the ground plate of FIG. However, such a ground plate has the advantage that it can be easily installed by the user, but requires a lot of man-hours for installation and is not possible for all vehicles.

The open-ended ground wire to be described below is a ground composed only of a conductor wire that can be bent without using any ground plate or the like. This open ground wire is applicable to all grounded antennas.
FIG. 69 shows a feeder assembly using an open type ground wire. In the figure, reference numeral 150 denotes a joint box having a slit 155 into which end portions 11, 21, 31 such as the antennas 10, 20, 30 of the first embodiment are inserted. A feeder line 152 and a ground line 151 are connected to the box 150. A ferrite core 53 and a connector 154 are attached to the feeder line for the purpose of removing noise. The connector 154 is connected to an FM radio, a TV tuner, or a VICS terminal (not shown) according to the purpose.

  As shown in FIGS. 70 and 71, the feeder line 152 has a net-like shield wound around the signal core line 156. A spring body 158 having elasticity 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. Further, the shields are combined into an earth lead wire 157, and the lead wire 158 is connected to a thicker earth core wire 157. The grounding core wire 159 is covered with an insulating coating and becomes the grounding wire 151 as a whole.

FIG. 116 shows a state where such a ground wire assembly is connected to the antenna 10 and attached to the windshield.
The open end type ground is characterized in that the end 160 is released, and is not particularly grounded to the vehicle body. Even if the end is released, it functions as a ground. The reason will be described with reference to FIGS.

FIG. 72 shows the structure of a conventional conventional grounded antenna. As shown in the drawing, the feeder ground wire is grounded to the vehicle body.
On the other hand, FIGS. 73 to 75 illustrate the principle of an open-ended earth wire as an embodiment of the present invention. As shown in FIG. 73, when one end of the open-ended 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 such as a curve 171 in FIG. 73 along the ground 151. That is, the potential on the ground wire has a tendency to gradually decrease. Here, as shown in FIG. 74, when the length of the ground wire 151 is set to 1/4 of the wavelength λ of the received radio wave, the voltage distribution on the line becomes a curve 173 (FIG. 74), and the transmission line The impedance of this transmission line viewed from the point 172 is 0 due to the nature, and the potential at the point 172 is equal to the vehicle body potential. That is, as shown in FIG. 75, the open-ended 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 example of FIGS. 73 to 75, an air layer exists between the ground wire forming the transmission line and the vehicle body, but if an insulator of an arbitrary material (line shortening rate δ) is interposed therebetween. The preferred length of the open-ended ground wire is
(Λ / 4) · δ (5)
It becomes.

  What is important here is that the open-ended ground wire does not have to be parallel to the feeder line, and it does not have to be in contact with the metal part of the vehicle body for the purpose of forming the vehicle body and the transmission line. It will be. In addition, the open-ended ground wire is preferably a conductor that can be bent in order to follow the vehicle body body if the position where the ground wire should be set is a place where the gap is narrow.

  In view of the ease of incorporating an open-ended ground wire into the vehicle body, in FIG. 69, the feeder wire 152 and the ground wire 151 are insulated from each other, and both wires are insulated from the vehicle body. It is preferable to cover with an insulating coating. Thus, the open-ended grounding wire can be grounded as compared to the conventional grounding method or the grounding plate of the present embodiment (FIG. 11) that requires some configuration such as screwing, bonding, and grounding pattern. There is an effect that it becomes very simple.

The performance as an earth of the open-ended earth wire having an extremely advantageous structure in assembly will be described below.
76 to 81 show the length of the open-ended ground wire when the open-ended ground wire is connected to the convex antenna 10 of the first embodiment and TV radio waves in the band of 90 MHz to 230 MHz are received. The VSWR characteristics when variously changed are shown. For comparison, FIG. 82 shows a VSWR characteristic diagram when the antenna 10 and the ground plate of FIG. 11 are combined, FIG. 83 shows a VSWR characteristic diagram when the antenna 10 is not provided with a ground, and FIG. 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 a direct ground or a ground plate on the body from the viewpoint of maximizing the function of the ground, the VSWR characteristic shown in FIG. 82 or 84 is the antenna 10 (FIG. 3). Therefore, an open-ended earth wire having the characteristics shown in FIG. 80 or FIG. 81 closest to the VSWR characteristic, that is, a ground wire having a length of 50 cm to 60 cm is preferable. .

In this way, the length of the open-ended ground wire is set to δ · λ / 4 (where δ is the line shortening rate of the substance interposed between the ground wire and the vehicle body) according to the wavelength of the received radio wave. As a result, it is possible to provide a ground wire that is easy to set up and has optimum reception performance.
Next, the influence of the open-ended ground wire on the reception sensitivity will be described.
85 to 92 show the reception sensitivity of the convex antenna 10 (also referred to as a T-type antenna in the drawing) shown in FIG. 85, 87, 89, and 91, the curve I indicates the characteristics of the antenna 10 when an open-ended ground wire is connected to the antenna 10, and the broken line II indicates the ground plate (FIG. 7) to be compared with the antenna 10. The characteristic of the antenna 10 when it connects to is shown. In particular, FIGS. 85 and 86 show the reception sensitivity when the length of the open-ended ground wire is set to 90 cm in order to receive radio waves in the 88 to 110 MHz band. It can be seen that 13.3 dB is obtained. 87 and 88 show the reception sensitivity when the length of the open-ended ground wire is set to 53.5 cm in order to receive radio waves in the 170 to 225 MHz band. It can be seen that a sensitivity of −12.3 dB is obtained. 89 and 90 show the reception sensitivity when the length of the open-ended ground wire is set to 30 cm in order to receive radio waves in the 170 to 225 MHz band. From FIG. 90, the average sensitivity is sufficient as sensitivity. It can be seen that 12.3 dB is obtained. 91 and 92 show the reception sensitivity when the length of the open-ended ground wire is set to 20 cm in order to receive radio waves in the 470 to 770 MHz band. It can be seen that 17.4 dB is obtained.

The graphs of FIGS. 85, 87, 89, and 91 indicate that the open-ended grounding wire exhibits the same characteristics as the grounding plate when its length is set appropriately.
FIG. 95 shows the sensitivity when radio waves in the 470 to 770 MHz band are received by the long frame antenna 20 of FIG. 4. In FIG. 95, the solid line I sets the length of the open-ended 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 a convex antenna such as the antenna 10, the maximum horizontal length x and the maximum vertical length y are:
y ≦ α ・ λ / 4
x ≦ 60cm-y
If the width of the portion below the 10 cm position from the upper end of the field of view range of the window glass is set to 6.6 cm or less, it can be seen that a preferable antenna device can be obtained.

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:
5cm ≦ x ≦ 40cm
3cm ≦ y ≦ 10cm
A preferable result was obtained.

When the open-ended grounding wire is applied to the round 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 ・ λ / 4
x ≦ 60cm-y
A preferable result was obtained.

Second Embodiment Side Glass Antenna In the second embodiment, the glass antenna of the present invention is applied to a side glass. In particular, 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. Further, since the VICS 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. 57), the windshield has many antenna wires. Depending on the type of vehicle, it may not be preferable. The antenna of 2nd Embodiment provides a VICS antenna in a side glass.

As the glass antenna of the second embodiment, a frame-shaped antenna is adopted, and the glass antenna design method of the first embodiment (1 and 2, and the design conditions of FIG. 30) is applied.
FIG. 97 shows a state where the frame-shaped glass antenna 200 of the second embodiment is attached to the side glass. The antenna 200 of FIG. 97 was connected to the open-ended ground wire (FIG. 69) of the first embodiment. The antenna 200 of FIG. 97 has all the features of the frame-shaped antenna of the first embodiment. Further, by connecting the antenna 200 to the open end ground wire, all the features of the open end ground wire of the first embodiment are inherited.

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

As long as the frame-shaped glass antenna of the second embodiment satisfies the above design conditions, the ground is not particularly limited to the open-ended ground wire. FIG. 98 shows an attachment state when the antenna 200 is connected to the ground plate.
FIGS. 100 to 110 show the length of an open-ended ground wire when an open-ended ground wire is connected to the VICS frame antenna 200 of the second embodiment and a TV radio wave in the band of 76 MHz to 108 MHz is received. The VSWR characteristics when the thickness is varied are shown. For comparison, FIG. 99 shows the characteristics when there is no ground, FIG. 111 shows the VSWR characteristics when the antenna 200 and the ground plate are combined, and FIG. 112 shows the characteristics when the antenna 200 is directly grounded to the vehicle body. The VSWR characteristic diagram is shown.

  The VSWR characteristics in FIG. 111 indicate that the antenna 200 according to the second embodiment provided with the ground plate is suitable for receiving FM radio waves in the VICS band. Further, from the graphs of FIGS. 100 to 110, when the antenna 200 of the second embodiment connected to the open-ended ground wire is used for receiving FM radio waves in the VICS band, the length of the open-ended ground wire is set to 80. It turns out that it is suitable to set to centimeter (FIG. 107) or 90 cm (FIG. 108).

113 and 114 show reception sensitivity characteristics when the length of the open-ended grounding wire is set to 90 cm and the VICS antenna 200 is provided on the side glass. In FIG. 113, the broken line indicates the characteristics when the ground is directly connected to the body to be compared.
<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 arranged on the rear window glass.

FIG. 115 shows an interior view of a vehicle in which the glass antenna 270 according to the third embodiment of the present invention is extended on the rear window glass as viewed from the lower inside of the vehicle. In the figure, 250 is a windshield, 251 and 252 are side glasses, and 253 is a rear glass.
A defogger 254 is extended on the rear glass 253, and an antenna conductor wire 262 is stretched vertically in the center of the defogger 254 in the vehicle width direction. The conductor 262 intersects each heat ray of the defogger 254 perpendicularly and is connected in a direct current manner.

  In the upper part of the rear window glass 253, there is a region where a defogger heat ray is not stretched. In this blank region, antennas 260 and 261 for radio (or TV) and an antenna 270 for VICS are extended. In FIG. 115, the antennas 260 and 261 have an eye shape, and the VICS antenna 262 has a frame shape.

The lowermost conductor wires in the width direction of the antennas 260 and 261 are close to the uppermost heat wire 254t of the defogger 254. Therefore, each of the antennas 260 and 261 is capacitively coupled to the conductor wire 262 provided in the vertical direction in the defogger via the defogger heat wire 254t.
Similarly, the VICS antenna 270 is capacitively coupled to the conductor antenna 262.

In order to capacitively couple the three antenna lines to the antenna conductor 262, the following is performed.
That is, if the vertical length of the antennas 270, 260, 261 is generally y, and the antenna shortening rate by the antenna conductor 262 having the length L is ω,
20cm ≦ y + ω ・ L ≦ 70cm
So that the length in the longitudinal direction y of each antenna is adjusted. The details of the open-ended earth wire with capacitive coupling are described in detail in Japanese Patent Application No. 6-205767 by the inventors of the present invention. In this case, especially for the VICS antenna 270, it is necessary to satisfy the above-described equations (1) and (2) and also satisfy the design conditions shown in FIG. Then, for the antenna 270,
x ≦ 30cm
20cm ≦ y + ωL ≦ 40cm
Is a preferred dimension.

  The VICS antenna 270 was grounded using the above-described open-ended ground wire. According to the antenna system of the third embodiment, it is possible to provide a diversity system that receives radio and TV radio waves and VICS radio waves. In the antenna system of the third embodiment, all of the advantages of the antenna of the first embodiment and the advantages of the open end type ground wire are inherited.

<Further deformation>
The first to third embodiments can be variously modified without departing from the spirit of the present invention.
(I): Although the shape of the glass antenna of the first to third embodiments was a convex shape (T-type), a long frame shape, and a round shape, the present invention can be applied to any antenna having a frame shape. Is possible. In this case, the frame may be present in the vicinity of the feeding point.

(Ii): Formula (2) applied to the frame type glass antennas of the first to third embodiments is based on 60 cm because glass is the base, but the base is other than glass. If it is a material (line shortening rate γ), 60 cm in the equation (2) is generally a predetermined 100 × γ cm. If the substrate shortening rate γ is smaller than that of glass (α≈0.6), 100 × γ becomes a value smaller than 60 cm. In this case, the size of the antenna itself can be reduced.
(Iii): The open-ended ground wire used in the first to third embodiments is used in a form bundled together with the feeder wire, but the ground wire applied to the present invention is Without limitation, for example, an open-ended ground wire may be spread on a glass surface using a thin and thin conductor on a sheet and separated from the feeder wire as an open-ended ground wire. The connection between the shield of the feeder line and the conductor is made 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-ended ground wire is (λ / 4) according to the equation (5).・ It becomes α.

The figure which shows the windshield of the vehicle to which the antenna system of 1st Embodiment of this invention was applied. The external view of the motor vehicle when the antenna of FIG. 1 is attached to the motor vehicle. The figure which shows the structure of the antenna 10 applied to the system of FIG. The figure which shows the structure of the antenna 20 applied to the system of FIG. The figure which shows the structure of the antenna 30 applied to the system of FIG. Sectional drawing which shows the structure of the antenna product before the antenna of FIG. 1 is spread. The figure which shows the structure of a ground plate in the antenna of FIG. The figure which looked in the car how to install the antenna system of FIG. The figure which shows the structure of the adapter for connecting an antenna to a ground plate The figure which shows the structure of a ground plate. The figure explaining a mode that a ground plate carries out capacitive coupling with the vehicle body. The figure explaining a mode that a ground plate carries out capacitive coupling with the vehicle body. The figure which shows the modification of the metal fitting for connecting earth | ground. The figure which shows the change of an average receiving sensitivity when x is changed variously when it is set as y = 5cm. The figure which shows the change of the receiving sensitivity which took the average within the evaluation frequency range when x is changed variously when it is set to y = 5cm. The figure which shows the change of an average receiving sensitivity when x is changed variously when it is set as y = 10cm. The figure which shows the change of the receiving sensitivity which took the average within the evaluation frequency range when x is changed variously when it is set to y = 10cm. The figure which shows the change of an average receiving sensitivity when x is changed variously when it is set as y = 15cm. The figure which shows the change of the receiving sensitivity which took the average within the evaluation frequency range when x is changed variously when it is set to y = 15cm. The figure which shows the change of an average receiving sensitivity when x is changed variously when it is set as y = 20cm. The figure which shows the change of the receiving sensitivity which took the average in the evaluation frequency range when x is changed variously when it is set to y = 20cm. The figure which shows the change of average receiving sensitivity when x is changed variously when it is set as y = 25cm. The figure which shows the change of the receiving sensitivity which took the average within the evaluation frequency range when x is changed variously when it is set to y = 25cm. The figure which shows the change of an average receiving sensitivity when x is changed variously when it is set as y = 30cm. The figure which shows the change of the receiving sensitivity which took the average within the evaluation frequency range when x is changed variously when it is set as y = 30cm. The figure which shows the change of an average receiving sensitivity when x is changed variously when it is set as y = 35cm. The figure which shows the change of the receiving sensitivity which took the average within the evaluation frequency range when x is changed variously when it is set to y = 35cm. The figure which shows the change of an average receiving sensitivity when x is changed variously when it is set as y = 40cm. The figure which shows the change of the receiving sensitivity which took the average within the evaluation frequency range when x is changed variously when it is set to y = 40cm. The graph which shows the relationship between the height x of the antenna system of embodiment, and the width y. The figure which shows the change of a receiving sensitivity when changing electric power feeding position by x = 10cm and y = 10cm. The figure which shows the change of a receiving sensitivity when changing electric power feeding position on x = 15cm and y = 10cm. The figure which shows the change of a receiving sensitivity when changing electric power feeding position by x = 20cm and y = 10cm. The figure which shows the change of a receiving sensitivity when changing electric power feeding position by x = 25cm and y = 10cm. The figure which shows the change of a receiving sensitivity when changing electric power feeding position by x = 30cm and y = 10cm. The figure which shows the change of a receiving sensitivity when changing electric power feeding position by x = 10cm and y = 3cm. The figure which shows the change of a receiving sensitivity when changing electric power feeding position by x = 15cm and y = 3cm. The figure which shows the change of a receiving sensitivity when x = 20cm and y = 3cm and a feed position is changed. The figure which shows the change of a receiving sensitivity when changing electric power feeding position on x = 25cm and y = 3cm. The figure which shows the change of a receiving sensitivity when changing electric power feeding position by x = 30cm and y = 3cm. The figure which shows the change of a receiving sensitivity when changing electric power feeding position by x = 35cm and y = 3cm. The figure which shows the change of a receiving sensitivity when x = 40cm and y = 3cm and a power feeding position is changed. The figure which shows the change of a receiving sensitivity when changing electric power feeding position by x = 5cm and y = 5cm. The figure which shows the change of a receiving sensitivity when changing electric power feeding position by x = 10cm and y = 5cm. The figure which shows the change of a receiving sensitivity when changing electric power feeding position by x = 15cm and y = 5cm. The figure which shows the change of a receiving sensitivity when x = 20cm and y = 5cm and a power feeding position is changed. The figure which shows the change of a receiving sensitivity when changing electric power feeding position by x = 25cm and y = 5cm. The figure which shows the change of a receiving sensitivity when changing electric power feeding position by x = 30cm and y = 5cm. The figure which shows the change of a receiving sensitivity when x = 35cm and y = 5cm and a power feeding position is changed. The figure which shows the change of a receiving sensitivity when changing electric power feeding position by x = 40cm and y = 5cm. The figure which shows the UHF receiving characteristic when changing the antenna width in y = 3cm in the antenna system of FIG. The figure which shows the UHF receiving characteristic (average receiving sensitivity in an evaluation frequency) when changing the antenna width in the antenna system of FIG. FIG. 3 is a diagram showing UHF reception characteristics when the antenna width is changed with y = 5 cm in the antenna system of FIG. 1. The figure which shows the UHF receiving characteristic (average receiving sensitivity in an evaluation frequency) when changing the antenna width in the antenna system of FIG. The figure which shows the UHF receiving characteristic when changing the antenna width in y = 10cm in the antenna system of FIG. The figure which shows the UHF receiving characteristic (average receiving sensitivity in an evaluation frequency) when changing the antenna width in the antenna system of FIG. The figure explaining the shape of the antenna of the said 1st modification. The figure which shows the vehicle windshield to which the antenna which concerns on the 1st modification of 1st Embodiment is applied. The figure explaining the receiving characteristic with respect to the electromagnetic wave of 88-110 MHz band of the antenna of the said 1st modification. The figure explaining the receiving characteristic with respect to the electromagnetic wave of 88-110 MHz band of the antenna of the said 1st modification. The figure explaining the receiving characteristic with respect to the 170-225 MHz band electromagnetic wave of the antenna of the said 1st modification. The figure explaining the receiving characteristic with respect to the 170-225 MHz band electromagnetic wave of the antenna of the said 1st modification. The figure explaining the receiving characteristic with respect to the 470-770 MHz band electromagnetic wave of the antenna of the said 1st modification. The figure explaining the receiving characteristic with respect to the 470-770 MHz band electromagnetic wave of the antenna of the said 1st modification. The figure explaining the shape of the antenna of the said 2nd modification. The figure which shows the vehicle windshield to which the antenna which concerns on the 2nd modification of 1st Embodiment is applied. The figure which shows the receiving characteristic with respect to the FM radio wave of the antenna which concerns on the said 2nd modification. The figure explaining the modification of the earth plate used for the antenna of 1st Embodiment. The figure explaining the structure of the end open type | mold earth wire used for the antenna of 1st Embodiment of this invention-3rd Embodiment. FIG. 70 is a diagram for explaining a part of the open-ended ground wire in FIG. 69 in detail. FIG. 70 is a diagram for explaining a part of the open-ended ground wire in FIG. 69 in detail. The figure explaining the body earth of a normal grounding type antenna. The figure explaining the principle of the end open type earth wire of an embodiment. The figure explaining the principle of the end open type earth wire of an embodiment. The figure explaining the principle of the end open type earth wire of an embodiment. The figure which shows the VSVR characteristic (10 cm in length of an earth wire) of the convex (T) form-shape antenna of 1st Embodiment. The figure which shows the VSVR characteristic (length of ground wire 20cm) of the convex (T) form-shape antenna of 1st Embodiment. The figure which shows the VSVR characteristic (length of ground wire 30cm) of the convex (T) form-shape antenna of 1st Embodiment. The figure which shows the VSVR characteristic (40 cm in length of an earth wire) of the convex (T) form-shape antenna of 1st Embodiment. The figure which shows the VSVR characteristic (length of ground wire 50cm) of the convex (T) form-shape antenna of 1st Embodiment. The figure which shows the VSVR characteristic (length of ground wire 60cm) of the convex (T) form-shaped antenna of 1st Embodiment. The figure which shows the VSVR characteristic (it uses an earth plate) of the convex (T) formwork-shaped antenna of 1st Embodiment. The figure which shows the VSVR characteristic (no earth | ground) of the convex (T) form-shape antenna of 1st Embodiment. The figure which shows the VSVR characteristic (the earth | ground is directly connected to the body) of the convex (T) form-shape antenna of 1st Embodiment. The figure which shows the receiving characteristic (88-110 MHz band) of the convex (T) form-shaped antenna of 1st Embodiment. The figure which shows the receiving characteristic (88-110 MHz band) of the convex (T) form-shaped antenna of 1st Embodiment. The figure which shows the receiving characteristic (170-225MHz band, earth length = 53.5cm) of the convex (T) form-shape antenna of 1st Embodiment. The figure which shows the receiving characteristic (170-225MHz band, earth length = 53.5cm) of the convex (T) form-shape antenna of 1st Embodiment. The figure which shows the receiving characteristic (170-225MHz band, earth length = 30cm) of the convex (T) form-shape antenna of 1st Embodiment. The figure which shows the receiving characteristic (170-225MHz band, earth length = 30cm) of the convex (T) form-shape antenna of 1st Embodiment. The figure which shows the receiving characteristic (470-770MHz band, earth length = 20cm) of the convex (T) form-shape antenna of 1st Embodiment. The figure which shows the receiving characteristic (470-770MHz band, earth length = 20cm) of the convex (T) form-shape antenna of 1st Embodiment. The figure which shows the receiving characteristic (170-225MHz band, earth length = 30cm) of the long frame-shaped antenna of 1st Embodiment. The figure which shows the receiving characteristic (170-225MHz band, earth length = 30cm) of the long frame-shaped antenna of 1st Embodiment. The figure which shows the receiving characteristic (470-770 MHz band, earth | ground length = 10cm) of the long frame shape antenna of 1st Embodiment. The figure which shows the receiving characteristic (470-770 MHz band, earth | ground length = 10cm) of the long frame shape antenna of 1st Embodiment. The figure which shows the side glass of the vehicle to which the glass antenna (open end type earth wire attachment) of 2nd Embodiment of this invention was applied. The figure which shows the side glass of the vehicle to which the glass antenna (ground plate attachment) of 2nd Embodiment of this invention was applied. The VSWR (no ground) characteristic diagram of the antenna of the second embodiment. The VSWR (earth wire length = 10 cm) characteristic diagram of the antenna of the second embodiment. The VSWR (earth wire length = 20 cm) characteristic diagram of the antenna of the second embodiment. The VSWR (earth wire length = 30 cm) characteristic diagram of the antenna of the second embodiment. The VSWR (earth wire length = 40 cm) characteristic diagram of the antenna of the second embodiment. The VSWR (earth line length = 50 cm) characteristic diagram of the antenna of the second embodiment. The VSWR (earth wire length = 60 cm) characteristic diagram of the antenna of the second embodiment. The VSWR (earth wire length = 70 cm) characteristic diagram of the antenna of 2nd Embodiment. VSWR (ground wire length = 80 cm) characteristic diagram of the antenna of the second embodiment. The VSWR (earth wire length = 90 cm) characteristic diagram of the antenna of the second embodiment. The VSWR (earth wire length = 100 cm) characteristic diagram of the antenna of the second embodiment. The VSWR (earth line length = 110 cm) characteristic view of the antenna of 2nd Embodiment. The VSWR (ground plate attachment) characteristic view of the antenna of 2nd Embodiment. The VSWR (directly on the body) characteristic diagram of the antenna of the second embodiment. The figure which shows the receiving characteristic of the antenna of 2nd Embodiment. The figure which shows the receiving characteristic of the antenna of 2nd Embodiment. The figure explaining the rear window glass of the vehicle which attached the antenna which concerns on 3rd Embodiment of this invention. The figure which shows the attachment state when the antenna which concerns on the said 1st Embodiment is attached to a windshield using an end open type | mold earth wire. The figure explaining the other form of the open end type | mold earth wire applicable to the antenna which concerns on 1st Embodiment-3rd Embodiment of this invention.

Claims (6)

A glass antenna spread on the front windshield of an automobile,
When the maximum length y in the vertical direction of the pattern of the glass antenna from the power feeding portion that is provided on the front window glass and substantially functions as a power feeding point, the wavelength of the reception frequency is λ, and the glass shortening rate is α. ,
y ≦ λ / 4 ・ α
Set to
The relationship between the maximum horizontal length x of the glass antenna pattern and the maximum vertical length y is
x + y ≦ 60cm
Set to
Furthermore,
The glass antenna, wherein the pattern has a shape surrounding the vehicle verification seal or the periodic inspection seal and is disposed at a position surrounding the vehicle verification seal or the periodic inspection seal . The glass antenna is grounded to the roof of the automobile, and the relationship between the maximum horizontal length x of the glass antenna pattern and the maximum vertical length y is
x> y
The glass antenna according to claim 1, wherein the glass antenna is set as follows. The glass antenna according to claim 1 or 2, wherein the pattern forms a enclose rectangular car verification seal.   4. The glass antenna according to claim 3, wherein the size of the opening of the pattern is larger than 70 mm in length and width.   5. The glass antenna according to claim 1, wherein the pattern is provided with a notch that prevents interference with a base of a rearview mirror. An antenna deployed on the front windscreen of a car,
The vertical maximum length y of the antenna pattern from the power supply unit that is provided at the top of the front window and substantially functions as a power supply point is λ, the wavelength of the reception frequency, and the shortening rate of the material of the front window α ′
y ≦ λ / 4 ・ α '
Set to
The relationship between the maximum horizontal length x of the antenna pattern and the maximum vertical length y is
x + y ≦ 100 cm × α ′
Set to
Furthermore,
The antenna has a shape surrounding the vehicle verification seal or the periodic inspection seal, and is arranged at a position surrounding the vehicle verification seal or the periodic inspection seal .

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