JPH05291817A - Printed antenna - Google Patents

Abstract

PURPOSE:To reduce the size of a printed circuit board. CONSTITUTION:An earth conductor layer 2 is provided on one side of a printed circuit board 1 and an antenna conductor layer 3 having nearly regular octal shape is provided on the other side to form the printed antenna. The antenna conductor layer 3 is formed so that the interval of at least a part of a couple of counter sides 3a is larger than the interval of other couples of counter sides 3b, 3c, 3d and the interval of at least a part of a couple of counter sides 3c not adjacent to the couple of the counter sides 3a is smaller than the interval of the other couples of the counter sides 3a, 3b, 3d. Since the interval of the couple of the counter sides 3c is decreased more than the interval of other couples of counter sides 3a, 3b, 3d, it is not required to take much increase in the interval of the couple of counter sides 3a set larger than the interval of the other couples of the counter sides 3b, 3c, 3d for the degeneration separation of the reception of a circularly polarized wave.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a print antenna suitable for incorporation in a mobile communication device mounted on a mobile body such as an automobile.

[0002]

2. Description of the Related Art GPS (Global Position)
An antenna used in a mobile communication device such as a Ning System receiving system is required to have a compact and thin form in order to be mounted on a mobile body such as an automobile. Therefore, a printed antenna as shown in FIG. 7 is provided. This printed antenna is a microstrip type antenna, and a double-sided copper-clad laminate is used to provide a ground conductor layer 2 with copper foil on one of the opposing one sides of a printed wiring board 1 forming a dielectric layer and the other one side. It is formed by providing the antenna conductor layer 3 with a copper foil patch. The printed antenna formed by using the double-sided copper-clad laminate as described above is widely used because it has uniform characteristics and is suitable for mass production. In FIG. 7, 10 is a feeding point 11 of the antenna conductor layer 3.
This is an antenna feeding portion formed by a through hole, a feeding pin, or the like for connecting between the antenna output terminal portion 12 and the.
Denoted at 5 is a convex portion for degenerate separation provided to receive circularly polarized waves. Further, 7 are mounting holes for mounting the printed antennas provided at the four corners of the printed wiring board 1 to the chassis or the like with screws.

The size of the antenna conductor layer 3 formed of the copper foil patch in this printed antenna is determined by the frequency of the radio wave used. That is, when the antenna conductor layer 3 is formed of square square patches, the peripheral length of the antenna conductor layer 3 is about 2 wavelengths (electrical length). Further, when the antenna conductor layer 3 is formed with a circular patch as shown in FIG. 7, the peripheral length is about 1.84 wavelength (electrical length). And
Assuming that the diameter of the antenna conductor layer 3 of the circular patch shown in FIG. 7 is A, the perimeter of the antenna conductor layer 3 is 3.14A.

Here, it has been found that even the antenna conductor layer 3 of a regular octagonal patch as shown in FIG. 8 has the same resonance frequency if the perimeter is equal to that of the circular patch.
If the distance between the opposite sides of the antenna conductor layer 3 of this regular octagonal patch is B, then the perimeter is 3.31B, so that B = 3.14A / 3.31≈0.95A for the same perimeter.
Therefore, the width and height can be made smaller by about 5% than the circular patch. Since the area of the rectangle surrounding the patch is reduced by about 10%, the area of the printed wiring board 1 can be reduced and the antenna can be downsized, and the number of the printed wiring boards 1 from the standard plate can be increased. It will be possible to achieve a low price. In order to further miniaturize the structure shown in FIG. 9, the antenna conductor layer 3 is formed in a shape in which every other side of the regular octagonal patch is formed into an arc, and the distance between the opposite sides of the straight line is C. Then, the perimeter becomes 3.4 C, and the vertical and horizontal widths of the patch can be made smaller by about 8% than the circular patch, and the area of the rectangle surrounding the patch can be reduced by about 15%. These points have already been filed as a patent application by the present applicant as Japanese Patent Application No. 3-329260.

By forming the antenna conductor layer 3 into a substantially regular octagonal patch as described above, the size of the antenna 3 can be reduced and the printed wiring board 1 can be miniaturized. In order to form the regular octagonal patch, degenerate separation convex portions 5 are provided on one pair of opposite sides, and the distance D between the one pair of opposite sides is equal to the distance between the other three pairs of opposite sides (particularly, this one pair of opposite sides). It is necessary to be larger than the distance between the pair of opposite sides and the pair of opposite sides which are not adjacent to each other. 8 and 9
As can be seen from the above, the convex portion 5 is generally provided in the space of the corner portion of the printed wiring board 1.

[0006]

Mounting holes 7 for mounting the printed antenna to the chassis or the like with screws are provided at the respective corners of the printed wiring board 1, and the degenerate separation convex portions 5 of the antenna conductor layer 3 are provided. Will be formed close to the mounting hole 7. However, the screw to be inserted into the mounting hole 7 is generally made of metal, that is, a conductor, and the tuning frequency of the antenna may be affected by the screw. For this reason, it is necessary to secure a separation distance between the degenerate separation convex portion 5 of the antenna conductor layer 3 and the mounting hole 7, and as a result, there is a problem that the size of the printed wiring board 1 must be increased.

The present invention has been made in view of the above points, and an object of the present invention is to provide a printed antenna capable of reducing the size of a printed wiring board.

[0008]

A printed antenna according to the present invention is formed by providing a ground conductor layer 2 on one surface of a printed wiring board 1 and an approximately octagonal antenna conductor layer 3 on the other surface. In the printed antenna described above, among the four pairs of opposite sides of the substantially regular octagon, one pair of opposite sides 3a has at least part of the gaps larger than the gaps of the other pair of opposite sides 3b, 3c, 3d. The antenna conductor layer 3 is formed so that at least a part of a pair of opposite sides 3c which are not adjacent to the opposite side 3a is smaller than a gap between the opposite sides 3a, 3b and 3d of the other set. To do.

[0009]

Out of the four pairs of opposite sides of the substantially regular octagon facing each other, at least a part of one pair of the opposite sides 3a is spaced from the other pair of opposite sides 3a.
The distance is larger than the distance between b, 3c and 3d, and at least a part of the distance between the pair of opposite sides 3c which is not adjacent to the opposite side 3a is smaller than the distance between the opposite sides 3a, 3b and 3d of the other pair. Since the antenna conductor layer 3 is formed like
At least a part of the distance between the pair of opposite sides 3c is set to be smaller than a distance between the opposite sides 3a, 3b, 3d of the other set, so that at least a part of the distance between the pair of opposite sides 3a, 3b, 3d is different for degenerate separation of circular polarization reception. It is not necessary to increase the size of the distance between the pair of opposite sides 3a so as to be larger than the distance between the opposite sides 3b, 3c, 3d of the pair.

[0010]

EXAMPLES The present invention will be described in detail below with reference to examples. Figure 1
Shows an embodiment of the present invention, by etching each copper foil using a double-sided copper-clad laminate,
The printed circuit board 1 is formed by providing the antenna conductor layer 3 with a copper foil patch on one surface facing the printed wiring board 1 and providing the ground conductor layer 2 with a copper foil on the other surface. The structure is the same as that shown in FIGS. The antenna conductor layer 3 is formed as a regular octagonal antenna patch. And out of the four opposite sides of the regular octagon,
Each pair of opposite sides 3a is provided with a protrusion 5 for degenerate separation, and each pair of opposite sides 3c not adjacent to this pair of opposite sides 3a is provided with a recess 6.

Thus, the protrusion 5a is provided on the opposite side 3a, and the opposite side 3 is formed.
By providing the concave portion 6 in c, the interval E of a part of one pair of opposite sides 3a among the four opposite sides of the regular octagon facing each other is larger than the spacing of the opposite sides 3b, 3c, 3d of the other set, and The antenna conductor layer 3 can be formed such that the interval F of a part of the pair of opposite sides 3c that is not adjacent to the pair of opposite sides 3a is smaller than the interval F of the other pair of opposite sides 3a, 3b, 3d. It is a thing. Then, the convex portion 5 is provided on one pair of the opposite sides 3a so that a part of the interval E of the opposite side 3a is different from the other sides 3b, 3c,
By forming the antenna conductor layer 3 so as to be larger than the distance between the opposite sides 3c which are not adjacent to each other, it is possible to obtain a circularly polarized wave receiving antenna. Since the concave portions 6 are provided on the opposite sides 3c which are not adjacent to each other, the concave portions 6 are provided and the distance F between the opposite sides 3c is shortened, so that the protrusion dimension of the convex portion 5 is shortened to reduce the opposite side 3c.
The distance between a can be shortened.

Since the projections 5 for degenerate separation can be shortened in this way, a sufficient separation distance between the projections 5 and the mounting holes 7 can be secured, and the four parts of the printed wiring board 1 can be secured. It is not necessary to increase the vertical and horizontal dimensions of the printed wiring board 1 while securing the mounting holes 7 at the corners of the places, and the printed antenna can be downsized.

In the embodiment shown in FIG. 2, the antenna conductor layer 3 is formed of a deformed regular octagonal patch.
That is, the entire length of the pair of opposite sides 3a is made to project, and the pair of opposite sides 3a that is not adjacent to the opposite side 3a.
In such a manner that the total length of c is set backward, the distance G between the opposite sides 3a of one of the four opposite sides of the substantially regular octagon facing each other is larger than the distance between the opposite sides 3b, 3c, 3d of the other set, and The antenna conductor layer 3 is formed so that the distance H between the pair of opposite sides 3a and the pair of opposite sides 3c which are not adjacent to each other is smaller than the distance between the opposite sides 3a, 3b and 3d of the other pair. In this embodiment, the degenerate separation for receiving circularly polarized waves can be performed by utilizing the entire side of the pair of opposite sides 3a.

In the embodiment shown in FIG. 3, the opposite side 3a and the opposite side 3b of the antenna conductor layer 3 in the embodiment shown in FIG. 2 are replaced by straight sides to arc sides a to form a substantially regular octagonal patch shape. Of the four pairs of opposite sides of the substantially regular octagon facing each other, the spacing I between one pair of opposite sides 3a is larger than the spacing between the opposite sides 3b, 3c, 3d of the other pair, and the pair of opposite sides 3a are adjacent to each other. The antenna conductor layer 3 is formed such that the distance J between the opposite sides 3c of one set that does not match is smaller than the distance J between the opposite sides 3a, 3b, 3d of the other set. In this embodiment, as described with reference to FIG. 9, the size of the antenna conductor layer 3 can be reduced by making the four sides of the substantially regular octagon into the arc sides a, so that the printed antenna can be further downsized. ..

In the embodiment shown in FIG. 4, the opposite side 3c of the antenna conductor layer 3 in the embodiment shown in FIG. 3 is concavely curved and is replaced with a concave arc side b to form a substantially regular octagonal patch shape. , Of the four pairs of opposite sides of the substantially regular octagon facing each other, the interval K of one pair of opposite sides 3a is the other pair of opposite sides 3b,
It is larger than the distance between 3c and 3d, and this pair of opposite sides 3
The antenna conductor layer 3 is formed such that the distance L between the pair of opposite sides 3c that are not adjacent to a is smaller than the distance between the opposite sides 3a, 3b, 3d of the other pair. In this embodiment, the two mounting holes 7 are provided at the corners of the printed wiring board 1 so as to face the concave arc sides b, and the isolation distance between the mounting holes 7 and the antenna conductor layer 3 is set. A large size is ensured so that the size of the printed wiring board 1 can be made smaller.

Of the above embodiments, the embodiment shown in FIG. 2 is taken as a representative, and the design frequency is 1575.42M.
Specific dimensions in the case of Hz are shown in FIG. FIG. 5 shows the outer dimensions of the printed wiring board 1 serving as an antenna board and the antenna conductor layer 3 formed of a copper foil patch, and the unit of the numbers in the figure is “mm”. The used printed wiring board 1 has a dielectric constant of 3.5 and a thickness of 5 mm. FIG. 6 is an antenna directivity characteristic diagram when a right-handed circularly polarized wave of 1575.42 MHz is received by this printed antenna. Despite its small size, the gain in the zenith direction is +5.3 dB, which is a performance sufficient for practical use. Is confirmed to have been obtained.

[0017]

As described above, the present invention provides a printed antenna in which a ground conductor layer is provided on one surface of a printed wiring board and a substantially octagonal antenna conductor layer is provided on the other surface. Of the four opposite sides of the rectangular shape, at least a part of the opposite sides of one set has an interval larger than the interval of opposite sides of the other set, and at least one of the opposite sides of the set that is not adjacent to the opposite side of the one set. Since the antenna conductor layer was formed so that the gap between the parts was smaller than the gap between the opposite sides of the other set, at least part of the gap between the opposite sides of one set was made smaller than the gap between the opposite sides of the other set. For the degenerate separation of circularly polarized wave reception, it is not necessary to take the dimension of the distance between the opposite sides of the pair so that at least a part of the distance becomes larger than the distance between the opposite sides of the other set, Small printed wiring board dimensions It is those that can Kusuru.

[Brief description of drawings]

FIG. 1 is a perspective view of an embodiment of the present invention.

FIG. 2 is a perspective view of another embodiment of the present invention.

FIG. 3 is a perspective view of still another embodiment of the present invention.

FIG. 4 is a perspective view of yet another embodiment of the present invention.

5 is a plan view showing specific dimensions in the embodiment of FIG.

6 is a directional diagram of the printed antenna of FIG.

FIG. 7 is a perspective view of a conventional example.

FIG. 8 is a perspective view of another conventional example.

FIG. 9 is a perspective view of still another conventional example.

[Explanation of symbols]

 1 printed wiring board 2 ground conductor layer 3 antenna conductor layers 3a to 3d opposite sides of antenna conductor layer

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiromichi Goto 1048, Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Works Co., Ltd.

Claims (1)

[Claims] 1. A printed antenna in which a ground conductor layer is provided on one surface of a printed wiring board and an antenna conductor layer having a substantially regular octagonal shape is provided on the other surface, and four pairs of opposite sides having substantially regular octagonal sides facing each other are provided. Of the pair of opposite sides, at least a part of which has an interval larger than that of another pair of opposite sides, and which does not adjoin this pair of opposite sides has at least a part of an interval of another pair. A printed antenna comprising an antenna conductor layer formed so as to be smaller than the distance between opposite sides.