JP3373239B2 - Glass antenna for car phone - Google Patents

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a glass antenna for a car telephone.

[0002]

2. Description of the Related Art A pole antenna has been conventionally used as an antenna for transmitting and receiving radio waves used in a car telephone.

[0003]

Although the pole antenna can be used practically as an antenna, it is normally used in the form of a rod protruding from the surface of the body on which the pole antenna is mounted, and as a protrusion, an unpleasant wind noise is generated during running. However, there is a problem in that the appearance is complicated and there is a problem in aesthetics, there is a risk of injuring a person, and there is a possibility of being mischievous during parking.

In view of the above-mentioned problems of the conventional pole antenna, the present invention provides an antenna conductor having a predetermined pattern on the surface of a glass plate such as a rear glass.
It is an object of the present invention to provide a glass antenna for a car telephone which makes it possible to obtain a practical antenna transmission / reception characteristic equivalent to that of a pole antenna.

[0005]

According to the present invention, there is provided a main antenna wire, which is a loop conductor of a substantially circular shape, a substantially elliptical shape, or a substantially polygonal shape, on a glass plate of a window of an automobile, a feeding point, and a main antenna. A phase adjustment line connecting a predetermined position of the line and the feeding point, and an antenna conductor including a connecting line extending from the vicinity of the shortest main antenna line to the feeding point and connecting the main antenna line and the feeding point, and, A glass antenna for a car telephone, which is characterized in that a ground conductor is provided in the vicinity of a feeding point.

Further, according to the present invention, a main antenna wire made of a substantially rectangular loop-shaped conductor is provided on a glass plate of an automobile window,
A feed point, a phase adjustment line that connects a predetermined position of the main antenna line to the feed point, and a connection that extends from near one corner of the main antenna line that is the shortest to the feed point and connects the main antenna line and the feed point A glass antenna for a car telephone, characterized in that an antenna conductor consisting of a wire and an earth conductor is provided near a feeding point.

[0007] Also, the present invention, the shape of the grounding conductors is the automobile telephone glass antenna is substantially symmetrical en <br/> antenna conductor.

[0008]

FIG. 1 shows a front view of a glass antenna for a car telephone according to an embodiment. Reference numeral 1 is a loop-shaped main antenna line, 2 is a feeding point, 3 is a connection line connecting the main antenna line 1 and the feeding point 2, and 4 is a phase adjustment line. 6 is a ground conductor,
Five of them are ground points. The main antenna line 1, the feeding point 2, the connecting line 3 and the phase adjusting line 4 form an antenna conductor.

The main antenna wire 1 of the embodiment is a loop-shaped rectangle extending in a substantially vertical direction. Effective length L _{1 of} the main antenna line 1 in the substantially vertical direction, Effective length L _{1 of} the main antenna line 1 in the substantially horizontal direction
₂ is preferably in the following range so that transmission and reception can be performed with good characteristics in a desired reception frequency band. λ · K ≧ L ₁ ≧ λ · K / 8 λ · K / 10 ≧ L ₂ ≧ λ · K / 100 where λ is the wavelength of the desired frequency and K is the shortening rate of the glass antenna, which is 0. .64.

The loop shape of the main antenna wire 1 is substantially circular (the term "circular is a concept including a circle, the same applies hereinafter"), substantially elliptical,
A substantially polygonal shape such as a substantially triangular shape or a substantially quadrangular shape can be used, and among these, a substantially rectangular shape or a substantially elliptical shape that is long in the substantially vertical direction is desirable in terms of improving transmission / reception characteristics.

The length of the connecting wire 3 is appropriately determined according to the conditions such as the structure around the antenna installation place. Connection line 3
Since the design of the length is changed depending on the vehicle type and the impedance of the antenna differs depending on the vehicle type, the impedance of the antenna at the feeding point 2 and the impedance of the coaxial cable or the like connected to the feeding point 2 are provided by providing the phase adjustment line 4. We are matching.

Main antenna line 1 to which the phase adjustment line 4 is connected
The position of and the length of the phase adjustment line 4 influence the antenna impedance, and by appropriately changing these,
The antenna impedance can be adjusted. The point where the phase adjustment line 4 is connected to the main antenna line 1 may be any position of the main antenna line 1 as long as the transmission / reception characteristics are improved.

Further, it is practically desirable that the length of the phase adjustment line 4 is λ · K / 2 or less. This is because, when λ · K / 2 is exceeded, the receiving sensitivity is lowered by about 3 dB as compared with the point where the same antenna impedance is λ · K / 2 or less.

2 to 8 show another embodiment of the phase adjusting line 4 different from the above embodiment. 9 and 10 show examples of the main antenna line 1 and the phase adjustment line 4 which are different from the above-described examples.

The ground point 5 is provided near the feeding point 2. The shape of the ground conductor 6 is preferably substantially symmetrical antenna conductor. When they are not substantially symmetrical, changes in directional characteristics are observed. However, in the case where the vehicle is affected by the vehicle body (grounding), it may be necessary to adjust the dimensions of the earth conductor 6 to make it asymmetric. In addition, the ground conductor 6
It is preferable that they are provided so as to face each other substantially parallel to the tenor conductor.
Good

The dimensions of each part in the embodiment (FIG. 1) are shown below.・ L ₁ = 49 mm ・ L ₂ = 8 mm ・ Feeding point 2 = 8 mm × 8 mm ・ Connecting line 3 = 13 mm ・ Phase adjusting line 4 vertical direction = 15 mm ・ Phase adjusting line 4 horizontal direction = 13 mm ・ Grounding point 5 = 8 mm × 8 mm・ Ground conductor 6 = Symmetric with antenna conductor

FIG. 11 shows the frequency characteristics of the receiving sensitivity when the phase adjustment line 4 is not provided (comparative example), when it is provided (example (FIG. 1)), and the conventional pole antenna (antenna length of 500 mm). Indicates. When the phase adjustment line 4 is not provided, the receiving sensitivity is low, whereas when it is provided, the sensitivity is high. This is because the antenna and the coaxial cable are impedance-matched by the phase adjustment wire 4.

[0018]

According to the present invention, since the transmission / reception characteristics for radio waves in the frequency band of a car telephone can be made equal to the receiving sensitivity of the conventional pole antenna, the pole antenna can be eliminated and the protrusion from the vehicle body surface of the car. Can be eliminated. Therefore, it is possible to provide a glass antenna for a car telephone which is desirable in terms of aesthetics of a car, eliminates unpleasant wind noise, and is not tampered with.

[Brief description of drawings]

FIG. 1 is a front view showing an embodiment .

Figure 2 is a front view showing a phase adjustment line 4 of a different shape than the embodiment shown in FIG.

Figure 3 is a front view showing a phase adjustment line 4 of a different shape than the embodiment shown in FIG.

Figure 4 is a front view showing a phase adjustment line 4 of a different shape than the embodiment shown in FIG.

Figure 5 is a front view showing a phase adjustment line 4 of a different shape than the embodiment shown in FIG.

Figure 6 is a front view showing a phase adjustment line 4 of a different shape than the embodiment shown in FIG.

Figure 7 is a front view showing a phase adjustment line 4 of a different shape than the embodiment shown in FIG.

Figure 8 is a front view showing a phase adjustment line 4 of a different shape than the embodiment shown in FIG.

FIG. 9 is a main antenna wire 1 having a shape different from that of the embodiment shown in FIG .
The front view which shows and the phase adjustment line 4 .

FIG. 10 is a main antenna wire having a shape different from that of the embodiment shown in FIG .
The front view which shows 1 and the phase adjustment line 4 .

FIG. 11 is a frequency characteristic diagram of the receiving sensitivity of the pole antenna of the example , the comparative example, and the related art .

[Explanation of symbols]

1: Main antenna line 2: Feed point 3: Connection line 4: Phase adjustment line 6: Earth conductor

Continuation of the front page (56) Reference JP-A-3-250906 (JP, A) JP-A-59-198006 (JP, A) JP-A-3-1703 (JP, A) JP-A-3-265202 (JP , A) JP-A-3-49402 (JP, A) JP-A-63-254804 (JP, A) Actually open 4-10409 (JP, U) Actually open 52-144638 (JP, U) Japanese Patent Publication 4-7843 (JP, B2) JP-B 35-14257 (JP, B1) JP-B 33-7320 (JP, B1) Jikken 3-2982 (JP, Y2) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01Q 1/32

Claims (3)

(57) [Claims] 1. A main antenna wire made of a loop conductor having a substantially circular shape, a substantially elliptical shape, or a substantially polygonal shape, a feeding point, a predetermined position of the main antenna line and a feeding point on a glass plate of an automobile window. An antenna conductor consisting of a phase adjustment line that connects the main antenna line and the connection line that connects the main antenna line and the feed point is provided near the feed point, and a ground conductor is provided near the feed point. A glass antenna for car phones, which is characterized by 2. A main antenna line made of a substantially rectangular loop conductor, a feeding point, and a phase adjusting line connecting a predetermined position of the main antenna line and the feeding point on a glass plate of an automobile window.
At the feeding point, an antenna conductor that is extended from the vicinity of one corner of the shortest main antenna line and that consists of a connection line that connects the main antenna line and the feeding point is provided, and a ground conductor is provided near the feeding point. A characteristic glass antenna for car phones. Wherein the shape of the grounding conductors is substantially symmetrical antenna conductor 請 Motomeko 1 or 2 car phone glass antenna according to.