JPH0918221A - Window glass antenna device - Google Patents

Abstract

PURPOSE: To improve the receiving sensitivity of a window antenna device by connecting together two points by means of a ground pattern as well as 1st and 2nd antenna patterns which are extended upward in length of 1/4 wavelength of a received radio wave. CONSTITUTION: A 1st antenna pattern 3 of length L1 and a 2nd antenna pattern 4 of length L2 are formed on a window glass 2 at 90 deg. and over two points 3b and 4b which are apart from a vertical line defining both patterns 3 and 4 as symmetrical axes by a prescribed distance respectively. For instance, if the circulation start point of an electric field is set at the pattern 4 for a right circulation double polarized wave, the signal received at the pattern 4 is sent to a feeding point 3a after the signal phase is delayed by 90 deg. by a phase adjustment means 5. When the electric field of a circularly polarized radio wave advances by 90 deg. from the circulation start point, the signal received at the pattern 3 is synthesized with the signal received from the pattern 4 and having a phase equal to the signal received at the pattern 4 at the point 3a. Thus the maximum received signal is obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a window glass antenna device for receiving circularly polarized radio waves by forming an antenna on a window glass of an automobile.

[0002]

2. Description of the Related Art As disclosed in Japanese Utility Model Laid-Open Publication No. 1-108603, a conventional window glass antenna device includes an antenna formed of a conductor pattern on a window glass and a phase for adjusting a phase of a received signal from the antenna. It is equipped with an adjustment mechanism and is configured to receive circularly polarized radio waves.

[0003]

In the conventional window glass antenna device, a phase adjusting mechanism for adjusting the phase of circularly polarized radio waves is provided outside the antenna formed with a conductor pattern on the window glass. However, there is a problem that the cost becomes high.

The present invention has been made to solve the above problems, and an object thereof is to provide a low-cost window glass antenna device for receiving circularly polarized radio waves.

[0005]

In order to solve the above-mentioned problems, a window glass antenna device according to the present invention is provided with a conductor pattern from two points which are arranged at a predetermined distance to the left and right with respect to a perpendicular line as an axis of symmetry. The first antenna pattern and the second antenna pattern, which are formed by expanding upward with an angle of ° and a length of ¼ wavelength of the received radio wave, are connected between two points inside the ground pattern, and It is characterized in that a phase adjusting means formed in a loop shape with a length of / 4 wavelength is provided.

Further, the window glass antenna device according to the present invention is characterized in that the ground pattern is formed by two planar conductor patterns sandwiching the phase adjusting means formed in a loop shape.

Further, in the window glass antenna device according to the present invention, the first antenna pattern, the second antenna pattern, the two planar ground patterns, and the phase adjusting means are formed between the films and attached to the window glass. It is characterized by the combination.

[0008]

In the window glass antenna device according to the present invention, the conductor pattern is used to provide an angle of 90 ° and a quarter wavelength of the received radio wave from two points which are arranged at a predetermined distance to the right and left with respect to the vertical line as the axis of symmetry. The first antenna pattern and the second antenna pattern, which are extended upward by the length, are connected to two points inside the ground pattern, and are formed in a loop shape with a length of ¼ wavelength of the received radio wave. Since it has a phase adjustment means,
The received signal from either one of the antenna patterns can be delayed.

Further, in the window glass antenna device according to the present invention, since the ground pattern is formed by the two planar conductor patterns sandwiching the phase adjusting means formed in the loop shape, the impedance matching between the antenna pattern and the feeding cable is matched. Can be taken.

Further, in the window glass antenna device according to the present invention, the first antenna pattern, the second antenna pattern, the two planar ground patterns and the phase adjusting means are formed between the films and attached to the window glass. The antennas can be retrofitted because they are matched.

[0011]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a block diagram of a window glass antenna device according to the present invention. In FIG. 1, a window glass antenna device 1 is a GP used in a car navigation system.
An example of receiving circularly polarized radio waves from the S satellite will be described.

On a window glass 2 of an automobile, a first antenna pattern 3 having a predetermined length L1 and a second antenna pattern 4 having a predetermined length L2 are formed by a conductor pattern at a predetermined distance from a perpendicular line which is an axis of symmetry. The two points 3b and 4b thus arranged are formed so as to be upward from each other at a predetermined angle θ (= 90 °).

The conductor pattern is, for example, fine silver particles,
An electrically conductive member such as an electrically conductive wire, an electrically conductive metal thin wire, or an electrically conductive metal foil formed by screen-printing an electrically conductive paste obtained by forming a low-melting-point glass powder or the like into a paste with an organic solvent and further firing the window glass 2. Are formed by using.

The length L1 of the first antenna pattern 3 and the length L2 of the second antenna pattern 4 are equal,
For example, the following length (L1 = L2 = λ /
4, λ: wavelength of received radio wave).

The phase adjusting means 5 has a first
A predetermined distance from the ground pattern 6 and the second ground pattern 7 of the first antenna pattern 4 and the first antenna from the lower end 4b of the second antenna pattern 4.
Of the received radio wave up to the lower end 3b of the antenna pattern 3 of
The conductor pattern having a length of 4 is formed in a loop shape, and the feeding point 3a is provided on the left side of the phase adjusting unit 5 and directly below the lower end 3b of the first antenna pattern 3.

Inside the phase adjusting means 5 at a predetermined distance,
The first ground pattern 6 is formed of a substantially rectangular planar conductor pattern.

On the outside of the phase adjusting means 5, a second ground pattern 7 is formed by a plane conductor pattern having two sides H and W of a predetermined length at a predetermined distance, and the second ground pattern 7 is formed. The feeding point 7a is provided on the ground pattern 7 in the vicinity immediately below the feeding point 3a.

Two sides H, W around the second ground pattern 7
It is desirable to set the lengths of 35 mm and 60 mm, respectively, when receiving circularly polarized radio waves of 1.5 GHz. The first ground pattern 6 and the second ground pattern 7 are connected by a jumper wire 8.

FIG. 2 shows an enlarged view of the phase adjusting means and the first and second ground patterns according to the present invention. In FIG. 2, the conductor pattern of the phase adjusting means 5 is based on a circuit constant determined by the inductance of the conductor pattern forming the first ground pattern 6 and the second ground pattern 7, the capacitance between the patterns, and the like. The signal is formed with a length of λ / 4 of the received radio wave so that the phase of the received signal from is delayed by 90 °.

Further, the impedance between the feeding points 3a and 7a is matched with the impedance of 50Ω of the unbalanced type feeding cable 9 which is connected between the feeding points, for example, the coaxial cable, and the phase adjusting means 5 and the first adjusting means. The distance 11 between the first ground pattern 6 and the distance 12 between the phase adjusting means 5 and the second ground pattern 7 are set to predetermined values.

In FIG. 1, the core wire 9a and the outer conductor 9b of the power supply cable 9 are connected to the power supply points 3a and 7a respectively, and the core wire 9c and the outer conductor 9d at the other end of the power supply cable 9 are respectively connected to the receiver 10. Connect to.

A circularly polarized radio wave from a GPS satellite is formed by an electric field obtained by combining an electric field in the x direction and an electric field in the y direction which is orthogonal to the electric field in the x direction and has a phase difference of 90 °. The direction of the electric field of the circularly polarized radio wave turns with time.

Circularly polarized radio waves have an electric field in the x direction of y
Right-handed circularly polarized wave if it is ahead of the electric field by 90 °,
Further, for example, when the electric field in the x direction lags the electric field in the y direction by 90 °, it becomes a left-handed circularly polarized wave.

Circularly polarized radio waves are converted into right-handed circularly polarized waves (see FIG. 1).
When viewed from the back side of the radio wave, the radio wave travels clockwise from the back side to the front side), and when the starting point of the turning of the electric field is set from the second antenna pattern 4, the received signal received by the second antenna pattern 4 is The phase is delayed by 90 ° by the phase adjusting means 5 and transmitted to the feeding point 3a.

The electric field of the circularly polarized radio wave is 90 degrees from the starting point of the turning.
In the advanced state, the received signal received by the first antenna pattern 3 and the received signal from the second antenna pattern 4 in phase with this received signal are combined at the feeding point 3a, and the maximum received signal is obtained. Is obtained.

In the following, the received signals received by the first antenna pattern 3 are sequentially acquired with the passage of time of the electric field of clockwise rotation,
By the phase adjusting means 5, a reception signal synthesized by the reception signals from the second antenna pattern 4 whose phase is delayed by 90 ° can be obtained.

In the present embodiment, in order to facilitate the explanation of the operation, the turning direction of the electric field of the radio wave is shifted by 90 °, but the direction is actually turning continuously, and at each time point, A combined reception signal is obtained based on the signal levels of the reception signals from the antenna pattern 3 and the second antenna pattern 4.

The combined reception signal corresponding to the reception signals from the first antenna pattern 3 and the second antenna pattern 4 is
Core wire 9 of the power supply cable 9 connected to the power supply points 3a and 7a
It is transmitted to the receiver 10 connected to the cores 9c and 9d on the output side of the power feeding cable 9 through the a and the outer conductor 9b.

A pattern (antenna pattern, ground pattern, phase adjusting means, etc.) for receiving left-handed circularly polarized radio waves (the radio waves travel counterclockwise from the back side to the front side when viewed from the back side in FIG. 1) ) Is formed in the same shape as the conductor pattern obtained by rotating the window glass 180 ° about the perpendicular line as the axis of symmetry.

The first antenna pattern 3, the second antenna pattern 4, the phase adjusting means 5, the first ground pattern 6, and the second ground pattern 7 are applied between the transparent insulating films on the back surface of which an adhesive is applied. Formed on the power feeding point 3
A sheet feeding antenna is formed by connecting a power feeding cable 9 to a and 7a so that a car dealer or a user can attach the sheet antenna on the window glass 2.

In the present embodiment, an example of receiving circularly polarized radio waves from GPS satellites used in a car navigation system is shown. For example, circularly polarized radio waves from broadcast satellites, communication satellites, etc. are received. In this case, the shapes and dimensions of the first antenna pattern 3, the second antenna pattern 4, the phase adjusting means 5, the first ground pattern 6, the second ground pattern 7, etc. are changed according to the characteristics of the radio wave. You may form it.

As described above, the window glass antenna device 1 according to the present invention is provided with the first antenna pattern 3, the second antenna pattern 4, and the phase adjusting means 5 formed on the window glass 2 by the conductor pattern, Receives polarized waves.

[0033]

The window glass antenna device according to the present invention has a 90 ° angle and 1/4 of the received radio wave depending on the conductor pattern from two points arranged at a predetermined distance to the left and right with respect to the perpendicular line as the axis of symmetry. The first antenna pattern and the second antenna pattern formed by extending upward with the length of the wavelength are connected to two points inside the ground pattern to
Since the phase adjustment means formed in a loop shape with a length of / 4 wavelength can delay the reception signal from either one of the antenna patterns, the reception sensitivity can be increased without providing an external phase adjustment mechanism. Therefore, the cost can be reduced.

Further, in the window glass antenna device according to the present invention, since the ground pattern is formed by two planar conductor patterns sandwiching the phase adjusting means formed in a loop shape, impedance matching between the antenna pattern and the feeding cable is matched. The reception sensitivity can be improved.

Further, in the window glass antenna device according to the present invention, the first antenna pattern, the second antenna pattern, the two planar ground patterns, and the phase adjusting means are formed between the films and attached to the window glass. The antenna can be retrofitted so that it can be attached to the dealer's car or the window glass of the car shipped from the factory by the user.

Therefore, it is possible to provide the window glass antenna device in which the antenna pattern and the phase adjusting means are formed by the conductor pattern on the window glass to simplify the structure and reduce the cost.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a window glass antenna device according to the present invention.

FIG. 2 is an enlarged view of phase adjusting means and first and second ground patterns according to the present invention.

[Explanation of symbols]

1 ... Window glass antenna device, 2 ... Window glass, 3, 11 ...
1st antenna pattern, 4, 12 ... 2nd antenna pattern, 5, 16 ... Phase adjusting means, 6 ... 1st earthing pattern, 7 ... 2nd earthing pattern, 8 ... Jumper wire, 9
... power feeding cable, 10 ... receiver, 11 ... distance between first ground pattern and phase adjusting means, 12 ... distance between second ground pattern and phase adjusting means, 3a, 7a ... feeding point, 9
a, 9c ... Core wire, 9b, 9d ... Outer conductor.

Claims (3)

[Claims] 1. A window glass antenna device comprising an antenna for receiving a circularly polarized radio wave on a window glass of an automobile, wherein conductors are provided from two points arranged at right and left with respect to a vertical line as an axis of symmetry. Depending on the pattern, the first antenna pattern and the second antenna pattern formed by expanding upward at an angle of 90 ° and a length of ¼ wavelength of the received radio wave and the two points are connected inside the ground pattern. , 1 / received radio wave
A window glass antenna device comprising phase adjusting means formed in a loop shape having a length of 4 wavelengths. 2. The window glass antenna device according to claim 1, wherein the ground pattern is formed by two planar conductor patterns sandwiching the loop-shaped phase adjusting means. 3. The first antenna pattern and the second antenna pattern
The antenna pattern, the two planar ground patterns, and the phase adjusting means are formed between the films and are attached to a window glass.
The window glass antenna device according to claim 2.