JPH07154123A - Glass antenna - Google Patents

Abstract

PURPOSE:To receive a very weak radio wave from a GPS satellite in an excellent way by arranging a couple of elements turned from a start point in the same direction as a rotating direction of a rotary polarized wave, extended up to the start point whose tips are kept open in point-symmetry. CONSTITUTION:A heater wire 2 for defrosting is arranged to a plate glass 1 at the cabin side and a 1st element 31, a 2nd element 32 are arranged to a lower space of the heater wire 2 so that circular-arc elements extended clockwise when viewing the outside from the inside of a window from a start point, returning to the vicinity of the start point whose tips are kept open are arranged in point-symmetry, First and second feeding points 41, 42 are provided to ends of the antenna 3, and formed to the lower space together with an FM radio use antenna 5 through screen print and conductive paste by means of baking. An inner conductor of a coaxial cable is connected to a feeding point 41 of the element 31 and an outer conductor of the coaxial cable is connected to a feeding point 42 of the element 32. Thus, an excellent directivity is obtained and the antenna is put into practical use sufficiently.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a glass antenna provided on a window glass for a moving body such as an automobile, a ship or an airplane.
Especially GPS (Global Positioning)
System) A glass antenna suitable for receiving weak radio waves from satellites and transmitting and receiving radio waves from broadcasting satellites, communication satellites, etc., and radio waves in the ultra-high frequency band such as car phones, personal radios, and commercial radios It is a thing.

[0002]

2. Description of the Related Art Conventionally, a microstrip antenna is known as an antenna for receiving weak radio waves from GPS satellites, as well as a quadrature dipole antenna, a helical antenna, etc. Because of the structure, not only is it unfavorable in terms of safety and appearance, but it also interferes with car washing,
Furthermore, there were drawbacks such as the possibility of breakage.

The present invention has been made in view of the above points, and is suitable for receiving weak radio waves from GPS satellites, and is being put into practical use for broadcasting satellites, communication satellites, car phones, personal radios, and practical applications. It is an object of the present invention to provide a glass antenna that can also be used as an antenna for a personal handyphone, etc.

[0004]

DISCLOSURE OF THE INVENTION The present invention is a glass antenna for receiving circularly polarized waves arranged on a window glass for a moving body, the glass antenna being seen from the inside of the window. A pair of elements, which extend from the starting point in the same direction as the circularly polarized wave to rotate in the same direction as the circularly polarized wave, extend to the vicinity of the starting point, and whose ends are open, are arranged so as to be point-symmetrical, and one element has an inside of the coaxial cable. The conductor is characterized in that an outer conductor is connected to the other element.

[0005]

In order to receive radio waves of right-handed circular polarization or left-handed circular polarization transmitted from GPS satellites, broadcasting satellites, communication satellites, etc., from the starting point to the satellite direction (from inside the window glass for a mobile unit) In the case of right-handed circularly polarized wave, it extends clockwise, and in the case of left-handed circularly polarized wave, it extends counterclockwise, returns to the vicinity of the starting point, and an element with an open tip is suitable for matching. .

Further, by forming at least a part of these elements wide or by providing a plurality of them, the directional characteristics are improved so that the GPS satellite or the like can be received at any position.

Furthermore, by arranging such elements in point symmetry, the receiving sensitivity is further enhanced.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the drawings. FIG. 1 is a front view showing a first embodiment in which a glass antenna of the present invention is provided on a rear window glass for an automobile, and FIGS. 2 to 8 are main part details showing an antenna portion of the first to seventh embodiments of the present invention, respectively. FIG. 9 is a directional characteristic diagram of the antenna in the first embodiment (the front and the rear represent the direction of the automobile), and FIG. 10 is a front view showing another embodiment in which the glass antenna of the present invention is provided on the rear window glass for the automobile. It is a figure.

Example 1 This is an example in which a single plate glass is mounted as a rear window glass of a vehicle. As shown in FIGS. 1 and 2, a heating wire 2 for anti-fog and anti-fog are provided on the inside of the plate glass 1 for the car. In the lower margin of the heating wire for use, arc-shaped elements that extend clockwise from the starting point as viewed from the inside of the window and return to the vicinity of the starting point and open the tip are arranged in point symmetry. The antenna 3 of the present invention composed of the first element 3 ₁ and the second element 3 ₂ described above, the first feeding point 4 ₁ arranged at each end,
A second feed point 4 _2, another antenna for receiving and another FM radio broadcast wave provided to heater strips top margin portion for antifogging 5
At the same time, it is formed by screen-printing a conductive paste on the lower margin and firing it.

After mounting such a window glass on the rear part,
The feeding point 4 of the _first element 3 ₁ is connected to the internal conductor of the coaxial cable, the second element 3 _{and second} feeding points 4 ₂
Connect the external conductor of the coaxial cable to.

The dimensions of each part of the glass antenna thus obtained are such that the radius of the outer arc is 30 mm, the length of the arc is 175 mm, the radius of the inner arc is 25 mm, and the length of the arc is 145 mm. By 1.57542G
The directional characteristics shown in FIG. 9 are obtained by measuring the directional characteristics when a right-handed circularly polarized wave of Hz is received and showing the relative ratio when a general microstrip antenna commercially available and put to practical use is set to 0 dB. It was confirmed that the characteristic diagram was obtained and almost the same good results were obtained, and that it could be sufficiently put to practical use.

Example 2 to Example 6 Example 2 shown in FIG. 3 has the same shape and size as Example 1, but is hollow without any conductive material, and Example 3 shown in FIG. It is formed by four arc-shaped elements, and the radius is 35mm, 30mm, 25m in order from the outside.
m, 20 mm, the length of each arc is 195 mm,
165 mm, 130 mm and 100 mm, FIG.
Example 4 shown in FIG.
The radius of the outer arc is 35 mm, the length is 210 mm, the radius of the inner arc is 30 mm, the length of the arc is 180 mm, and the radius of the outer arc is 2 for the wide inner element.
5mm, length 135mm, inner radius of arc 20m
m, the length of the arc is 100 mm, and in Example 5 shown in FIG. 6, a square element is formed wide and cut at the feeding point, and the dimensions of each part are a = b = 48.
mm, c = 10 mm, d ₁ = d ₂ = d ₃ = e = 5 mm, Example 6 shown in FIG. 7 is one in which a triangular element is formed by a line and cut at the feeding point. The dimensions of each part are f = 55 mm, g = 55 mm, h = 7
The auxiliary element 6 is added in addition to 0 mm and the total length is 180 mm, and the other configurations are the same as those of the first embodiment.

With such an antenna, 1.575
The directional characteristics when a right-hand circularly polarized wave of 42 GHz is received are measured and shown as a relative ratio when a general microstrip antenna commercially available and put to practical use is set to 0 dB. The directional characteristics of Example 5 were almost the same as those of Example 1, and the directional characteristics of Examples 2, 4, and 6 were similar to those of Example 1.

Embodiment 7 In Embodiment 7 shown in FIG. 8, radio waves from a broadcasting satellite or a communication satellite are transmitted in left-hand circular polarization instead of right-hand circular polarization in some countries. The antenna is a circularly polarized wave receiving antenna, in which the first element 3 ₁ and the second element 3 ₂ are formed counterclockwise in a state where the outside is seen from the inside of the window.

Other Embodiments The preferred embodiments have been described above, but the present invention is not limited to these, and various applications are possible.

For the first and second elements, an elliptical shape or a polygonal shape of pentagonal shape or more can be adopted in addition to the arc shape, the quadrangular shape, and the triangular shape, and all of them may be formed by the filaments. However, it is better to form at least a part wider.

Further, when it is provided on a rear window glass for a vehicle or the like, since the space in the vertical direction is smaller than the space in the horizontal direction, the entire antenna is formed as a horizontal filament as shown in Examples 1 to 7. It is preferable to have a horizontally long structure, but if there is space, it will be 9 as shown in FIG.
Of course, it may be rotated by 0 ° to be vertically long.

Further, it is preferable in terms of design that the first element and the second element, which are in a point-symmetrical relationship, be completely point-symmetrical, but the dimensions may be slightly different.

Further, in all the embodiments, the first element and the second element may be reversed. That is, the inner conductor and the outer conductor of the coaxial cable may be connected in reverse.

Although the distance between the first feeding point and the second feeding point is narrowed to about 3 mm to 5 mm in any of the embodiments, the first feeding point may be separated by, for example, about 100 mm and a low noise amplifier or the like may be provided therebetween. You may make it connect to a point and a 2nd feeding point.

Although the auxiliary element is not always necessary, various elements are connected to the first element or the external conductor to which the inner conductor is connected for the purpose of improving directional characteristics, adjusting impedance, and improving reception gain. Can be added to the second element.
Generally, the effect is greater when added to the first element, but in some cases it is better to add it to the second element.

The location of the antenna 3 is not limited to the central portion of the lower margin of the anti-fogging heating wire on the rear window glass of the vehicle, but also to the side of the lower margin or to the upper margin as shown in FIG. It may be provided on the front window glass or the sunroof. In addition to the vehicle, it may be provided in a window of an aircraft or a ship.

Regarding the conductive material forming the antenna, when the entire element is formed wide as in the case of the fifth embodiment, a transparent conductive film such as a sputtered film can also be used. When a laminated glass is used as the rear window glass, a thin metal wire such as a copper wire may be embedded in the intermediate film.

[0024]

The glass antenna of the present invention has the first and second glass antennas.
With a unique shape, the element can receive weak radio waves from GPS satellites at a practical level even if the arrival direction changes, and can be used as an antenna for car phones and personal radios. Is.

[Brief description of drawings]

FIG. 1 is a front view showing a first embodiment in which a glass antenna of the present invention is provided on a rear window glass for an automobile.

FIG. 2 is a detailed view of a main part showing only an antenna part according to the first embodiment of the present invention.

FIG. 3 is a detailed view of a main part showing only an antenna part according to a second embodiment of the present invention.

FIG. 4 is a detailed view of a main part showing only an antenna part according to a third embodiment of the present invention.

FIG. 5 is a detailed view of a main part showing only an antenna part according to a fourth embodiment of the present invention.

FIG. 6 is a detailed view of a main part showing only an antenna part according to a fifth embodiment of the present invention.

FIG. 7 is a detailed view of a main part showing only an antenna part according to a sixth embodiment of the present invention.

FIG. 8 is a detailed view of a main part showing only an antenna part according to a seventh embodiment of the present invention.

FIG. 9 is a directional characteristic diagram of the antenna according to the first embodiment (before,
The rest represents the direction of the car).

FIG. 10 is a front view showing another embodiment in which the glass antenna of the present invention is provided on a rear window glass for an automobile.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Flat glass 2 Heating wire for anti-fog 3 ₁ 1st element 3 ₂ 2nd element 3 Antenna of this invention 4 ₁ 1st feeding point 4 ₂ 2nd feeding point 5 Another antenna 6 Auxiliary element

Claims (1)

[Claims] 1. A glass antenna for receiving a circularly polarized wave disposed on a window glass for a mobile body, wherein the circularly polarized wave is transmitted from the starting point in a state where the outside is seen from the inside of the window. A pair of elements that turn in the same direction as the turning direction, extend to the vicinity of the starting point, and have open ends are arranged in point symmetry, and one element is the inner conductor of the coaxial cable and the other element is the outer conductor. A glass antenna characterized by being connected to.