JPH06276009A - Frequency switching type glass antenna - Google Patents

Abstract

PURPOSE:To provide the frequency switching type glass antenna which can be arranged in nearly the same space with a monopole antenna. CONSTITUTION:A 1st pattern 2 for radiation is arranged on a glass surface vertically, a 2nd pattern 3 for radiation is arranged above it, and a grounding pattern 4 is arranged below it to form the glass antenna 1. The 1st and 2nd patterns 2 and 3 for radiation can be short-circuited by a jumper line 5. Namely, the patterns for radiation vary in length according to whether the jumper line 5 is short-circuited or not, so resonance to two kind of frequencies is obtained. Further, the grounding pattern 4 is used in common, so the overall size is nearly equal to that of the monopole antenna and the antenna can be arranged in a relatively small space.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a glass antenna arranged mainly on a window glass of a vehicle.

[0002]

2. Description of the Related Art A window glass antenna filed by the present applicant as an example of a conventional window glass antenna (Japanese Patent Application No. 4-386).
No. 28) is shown in FIG. This window glass antenna 80 has a radiation pattern 8 in the vertical direction of the glass surface.
1 is provided, and a grounding pattern 82 having a hollow shape is provided below. And the radiation pattern 8
1, the core wire of the power feeding coaxial cable is connected to the lower end portion 81a, the braided wire of the power feeding coaxial cable is connected to the upper end central portion 82a of the grounding pattern 82, and the other end of this cable is connected to an antenna of a car telephone device or a radio. It was connected to the terminal.

Since the antenna is formed on the glass surface as described above, the projection like the whip antenna is eliminated, and the air resistance during running of the vehicle can be reduced. It was also suitable in terms of improving the appearance.

[0004]

However, since the window glass antenna 80 is a so-called monopole antenna (antenna for a single frequency), another set of antennas must be prepared for use at different frequencies. . However, arranging two sets of monopole antennas on one window glass requires double the space. Therefore, an object of the present invention is to provide a frequency switchable glass antenna that can be arranged in a space similar to a monopole antenna.

[0005]

In order to solve the above problems, the present invention provides a first radiation pattern in the vertical direction of a glass surface, and a second radiation pattern above the pattern. A grounding pattern is provided below the first radiation pattern to short-circuit or open the first and second radiation patterns.

The vertical length of the first radiation pattern is about (1/4) λ1 for the first wavelength λ1, and the vertical lengths of the first and second radiation patterns for the second wavelength λ2. The total length in the direction is about (1/5) λ2 to about (1/4) λ
The length of the second radiation pattern is set to be 2,
The vertical length of the ground pattern is approximately (1/4) λ
1 to about (1/4) λ2, and the length of the ground pattern in the left-right direction may be about (1/4) λ2 to about (3/4) λ1.

The grounding pattern may have a hollow shape.

[0008]

Since the first radiation pattern and the second radiation pattern are arranged vertically and the two patterns are short-circuited or opened, the resonance frequency can be switched in two ways. Further, since the grounding pattern is shared, the structure is almost the same as that of the monopole antenna except that the radiation pattern is arranged above and below. Therefore, the size can be made similar to that of a monopole antenna, and the antenna can be arranged in a relatively narrow space.

By setting the sizes of the radiation pattern and the ground pattern according to certain conditions, it is possible to obtain frequency characteristics close to those of a monopole antenna.

The visibility can be improved by forming the grounding pattern in a hollow shape.

[0011]

Embodiments of the present invention will be described below with reference to the accompanying drawings. In addition, 800MHz band and 1.5G
The antenna for the Hz band will be described, but the frequency is not limited to these frequencies.

FIG. 1 is an antenna pattern diagram of a first embodiment of a frequency switching type glass antenna according to the present invention. The frequency switching type glass antenna 1 is used for a rear window glass W of a vehicle or the like.
Vertically elongated first radiation pattern 2 arranged vertically
And a vertically elongated second radiation pattern 3 arranged above the pattern 2, and a vertically and horizontally long grounding pattern 4 arranged below the first radiation pattern 2.

FIG. 2 is a block diagram of the essential parts of the first embodiment. The upper end 2a of the first radiation pattern 2 and the lower end 3a of the second radiation pattern 3 are short-circuited by a jumper wire 5 using a conductive member such as a copper wire. The jumper wire 5 is connected by soldering or the like, but can be removed if necessary. Further, the core wire 6a of the feeding coaxial cable 6 is connected to the lower end portion 2b of the first radiation pattern 2, and the ground braided wire 6b of the cable 6 is connected to the upper end central portion 4a of the grounding pattern 4. The other end of the cable 6 is connected to an antenna terminal of a car telephone device or a radio (not shown).

On the other hand, the size of each pattern is determined by the following relationship. That is, when the wavelength with respect to the resonance frequency f (Hz) is λ (m), the wavelength is obtained by the following equation.

[0015]

[Formula 1] λ = (c / f) · k

Where c is the speed of light (3 · 10 ⁸ m / se)
c. ), K is the shortening rate (0.6) of the glass antenna in the present embodiment.

According to this equation 1, the wavelength λ1 for 1.5 GHz is 0.12 m. By the way, the length of the first radiation pattern 2 is set to about (1/4) λ1 with respect to this λ1. Therefore, in this embodiment, the first radiation pattern 2 is used.
Has a length of 30 mm.

Similarly, the wavelength λ2 for 800 MHz is 0.225 m according to the equation (1). By the way, the length of the second radiation pattern 3 is set as follows. That is, the total of the vertical lengths of the first radiation pattern 2 and the second radiation pattern 3 with respect to the second wavelength λ2 is about (1/5) λ2 to about (1/4) λ2. 2 Set the length of the radiation pattern 3.

Therefore, the total length of the two radiation patterns 2 and 3 should be within the range of about 45 mm to about 56 mm.
The length of the radiation pattern may be determined. In this embodiment, the total length is set to 45 mm. That is, the length of the first radiation pattern 2 was set to 30 mm, the length of the second radiation pattern 3 was set to 10 mm, and the distance between the two radiation patterns 2 and 3 was set to 5 mm.

On the other hand, for the wavelengths λ1 and λ2, the vertical length of the grounding pattern is approximately (1/4) λ1 to approximately (1 /).
4) Set λ2 to the horizontal length of the grounding pattern from about (1/4) λ2 to about (3/4) λ1. That is,
The vertical length may be set within a range of about 30 mm to about 56 mm, and the horizontal length may be set within a range of about 56 mm to about 90 mm. In this embodiment, the vertical length is 35 m.
m, and the length in the left-right direction was set to 60 mm.

That is, the first and second jumper wires 5 are used.
When the radiation patterns 2 and 3 are short-circuited, the wavelength λ2 (80
(0 MHz) and when the jumper wire λ2 is removed, only the first radiation pattern is effective, so the wavelength λ
It resonates at 1 (1.5 GHz). Therefore, the resonance frequency can be switched only by detaching the jumper wire 5. Further, except that the radiation patterns 2 and 3 are arranged above and below, it is the same as the conventional monopole antenna, so that it can be arranged in a relatively narrow space.

FIG. 3 is a partially enlarged view of the second embodiment. The second embodiment uses a connector type jumper wire 7 instead of the jumper wire 5 of the first embodiment. The connector type jumper wire 7 is composed of a conductive member 7a such as a copper wire and plugs 7b and 7c connected to both ends of the conductive member 7a. A plug (not shown) that can be attached to and detached from the plug 7b is provided on the upper end portion 2a of the first radiation pattern 2, and when the plug 7b is fitted into the jack, the plug 7b and the radiation pattern 2 are connected to each other. The connection portions 2c and 2d of 1 are soldered. If the plug 7b and the jack can be formed so as not to come off easily, the soldering may be omitted. Similarly, a jack (not shown) that can be attached to and detached from the plug 7c is provided at the lower end portion 3a of the second radiation pattern 3, and when the plug 7c is fitted into the jack, the plug 7c and the radiation pattern are inserted. The connection portion (not shown) with 3 was soldered.

If the jumper wire is of the connector type as described above, the attaching and detaching work becomes easy.

FIG. 4 shows the 800 MHz antenna of the first embodiment.
5 is a frequency characteristic graph for the z band, FIG. 5 is a frequency characteristic graph for the 1.5 GHz band of the antenna of the first embodiment, and FIG. 6 is measurement data of the frequency characteristic of the antenna of the first embodiment.

In the figure, the 800M standard is the case of a monopole antenna with a resonance frequency of 800 MHz among the above-mentioned conventional window glass antennas, and the 1.5G standard is the case of a resonance frequency among the above-mentioned window glass antennas. 1.5 GHz
This is the case of the monopole antenna. The common use (earth 1) means the grounding pattern of the first embodiment (35 m in the vertical direction).
m, 60 mm in the left-right direction), and shared (ground 2) is the case where a pattern slightly wider than the grounding pattern of the first embodiment (50 mm in the vertical direction, 90 mm in the horizontal direction) is used. The gain (dipole ratio) with respect to the frequency is shown with the gain of the standard dipole antenna being 0 dB.

According to FIG. 4, compared to the 800M standard, the shared (ground 2) has substantially the same characteristics, and the shared (ground 1) has a slightly lower overall gain, but has practically sufficient characteristics. . On the other hand, according to FIG. 5, compared to the 1.5G standard, the shared (earth 1) has substantially the same characteristics, and the shared (earth 2) is substantially the 1.5G standard at a frequency lower than the center frequency (1480 MHz). Equivalent characteristics can be obtained, but the gain is slightly reduced at high frequencies. However, the degree of decrease is almost equal to that of the common (earth 1) in the 800M standard, and it can be said that the characteristic is practically sufficient.

That is, if the size of the radiation pattern and the size of the ground pattern are determined based on the above-described conditions for the target frequency, the frequency switching type glass antenna can be formed with characteristics close to those of a monopole antenna.

FIG. 7 is an antenna pattern diagram of the third embodiment. This example is composed of two radiation patterns 11 and 12 arranged in the vertical direction and a grounding pattern 13 arranged below the pattern 12. Since this grounding pattern 13 is formed in a hollow shape, the field of view can be improved.

8 to 11 show another embodiment of the window glass antenna. FIG. 8 is an antenna pattern diagram of the fourth embodiment. In this example, two radiation patterns 21 and 22 arranged in the vertical direction and a relatively wide grounding pattern which is arranged below the pattern 22 and has a lower side 23a formed in an arc shape. 23 and. This lower side 23a
The visibility can be improved by arranging the patterns 21 to 23 along the lower edge Wa of the rear window glass W and disposing the patterns 21 to 23 at the corners of the window glass as a whole.

FIG. 9 is an antenna pattern diagram of the fifth embodiment. In this example, a T-shaped radiation pattern 31 and a radiation pattern 32 arranged below the pattern 31.
And a grounding pattern 33 disposed below the pattern 32. The radiation pattern 21 of the fourth embodiment is set to T
The grounding pattern 23 has a rectangular shape.

FIG. 10 is an antenna pattern diagram of the sixth embodiment. In this example, a V-shaped radiation pattern 41 and a radiation pattern 42 arranged below the pattern 41.
And a grounding pattern 43 disposed below the pattern 42. The T-shaped pattern 31 of the fifth embodiment is set to V
It is a letter.

FIG. 11 is an antenna pattern diagram of the seventh embodiment. In this example, an inverted L-shaped radiation pattern 51 and a radiation pattern 52 arranged below the pattern 51.
And a grounding pattern 53 disposed below the pattern 52. The V-shaped pattern 41 of the sixth embodiment has an inverted L-shape.

[0033]

Since the first radiation pattern and the second radiation pattern are arranged vertically and the two patterns are short-circuited or opened, the resonance frequency can be switched in two ways. Further, since the grounding pattern is shared by one, the configuration is almost the same as the monopole antenna except that the radiation pattern has a two-stage configuration. Therefore, the size can be made similar to that of a monopole antenna, and the antenna can be arranged in a relatively narrow space.

By setting the sizes of the radiation pattern and the ground pattern according to certain conditions, it is possible to obtain frequency characteristics close to those of a monopole antenna.

The visibility can be improved by forming the grounding pattern in a hollow shape.

[Brief description of drawings]

FIG. 1 is an antenna pattern diagram of a first embodiment of a frequency switching type glass antenna according to the present invention.

FIG. 2 is a configuration diagram of a main part of the first embodiment.

FIG. 3 is a partially enlarged view of the second embodiment.

FIG. 4 is a frequency characteristic graph for the 800 MHz band of the antenna of the first embodiment.

FIG. 5 is a frequency characteristic graph for the 1.5 GHz band of the antenna of the first embodiment.

FIG. 6 is measurement data of frequency characteristics of the antenna of the first embodiment.

FIG. 7 is an antenna pattern diagram of the third embodiment.

FIG. 8 is an antenna pattern diagram of the fourth embodiment.

FIG. 9 is an antenna pattern diagram of the fifth embodiment.

FIG. 10 is an antenna pattern diagram of the sixth embodiment.

FIG. 11 is an antenna pattern diagram of the seventh embodiment.

FIG. 12 is an antenna pattern diagram of a conventional window glass antenna.

[Explanation of symbols]

1 ... Frequency switching type glass antenna, 2, 12, 22,
32, 42, 52 ... First radiation pattern, 3, 11,
21, 31, 41, 51 ... Second radiation pattern, 4,
13, 23, 33, 43, 53 ... Grounding pattern, 5 ...
..Jumper wires, 7 ... Connector type jumper wires, W ...
Window glass.

Claims (3)

[Claims] 1. A first radiation pattern is arranged vertically on a glass surface, a second radiation pattern is arranged above this pattern, and a grounding pattern is arranged below the first radiation pattern. A frequency-switching glass antenna, which is configured to short-circuit or open the first and second radiation patterns. 2. The vertical length of the first radiation pattern is about (1/4) λ1 with respect to the first wavelength λ1, and
The total length of the first and second radiation patterns in the vertical direction is about (1/5) λ2 to about (1/4)
The length of the second radiation pattern is set to be λ2, and the vertical length of the ground pattern is approximately (1 /
4) λ1 to about (1/4) λ2, and the length of the ground pattern in the left-right direction is about (1/4) λ2 to about (3/4) λ.
The glass antenna according to claim 1, wherein the glass antenna is a frequency-switchable glass antenna. 3. The frequency switching glass antenna according to claim 1, wherein the grounding pattern has a hollow shape.