JP2582965B2 - Planar antenna - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a planar antenna.

[0002]

2. Description of the Related Art As a conventional planar antenna for receiving vertically and horizontally polarized radio waves, a first feeding circuit board 2a, a first radiating circuit board 3a, In some cases, the second power supply circuit board 2b and the second radiation circuit board 3b are sequentially stacked via the dielectric layer 6 such that the respective intervals are all equal. This planar antenna is formed such that the polarizations of the first feeding circuit board 2a and the first radiating circuit board 3a and the second feeding circuit board 2b and the second radiating circuit board 3b are orthogonal to each other. . That is, as shown in FIG. 4, the first power supply circuit board 2a and the second power supply circuit board 2b are formed by rotating the power supply line pattern by 90 degrees and making the power supply line 4 orthogonal.
a, 4b, and electromagnetically coupled to the feeder lines 4a, 4b formed on the feeder circuit boards 2a, 2b and the corresponding slot-type radiating elements 5a, 5b of the respective radiator circuit boards 3a, 3b. Have been.

[0003]

By the way, in the configuration of the above-mentioned conventional planar antenna, reception is performed by the antenna composed of the first feeding circuit board 2a and the first radiating circuit board 3a on the ground conductor plate 1. There is a problem that the signal gain is slightly blocked by the second radiating circuit board 3b, thereby lowering the antenna gain.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to reduce a signal blocked by a second radiating circuit board to reduce a ground conductor and a first conductor. Another object of the present invention is to provide a planar antenna in which the gain of an antenna constituted by the feed circuit board and the first radiation circuit board is improved. It is another object of the present invention to provide a planar antenna capable of obtaining a balanced antenna gain by making the gains of the upper layer antenna and the lower layer antenna substantially equal to each other.

[0005]

In order to achieve the above-mentioned object, according to the first aspect of the present invention, a first feeder circuit board, a first radiating circuit board, and a second feeder board are provided on a ground conductor plate. The circuit board and the second radiating circuit board are sequentially laminated with a dielectric layer interposed therebetween, and the first feeding circuit board and the first radiating circuit board are connected to the second feeding circuit board and the second radiating circuit board. In the planar antenna formed so that the polarized waves are orthogonal to each other, the distance between the first radiating circuit board, the second feeding circuit board, and the second radiating circuit board is determined by setting the distance between the ground conductor plate and the first feeding circuit board. The distance between the circuit board and the first radiating circuit board is smaller than the respective distances.

According to a second aspect of the present invention, the distance between the ground conductor plate, the first feeding circuit board, and the first radiating circuit board is set to about 1/10 of the wavelength of the operating frequency, and the first radiation Circuit board,
Each interval between the second feeding circuit board and the second radiating circuit board is set to be about 1/20 of the working frequency.

[0007]

According to the present invention, the first radiation circuit board,
Since the respective gaps between the second feeding circuit board and the second radiating circuit board were narrower than the respective gaps between the ground conductor plate, the first feeding circuit board, and the first radiating circuit board, the second Signals blocked by the radiation circuit board can be reduced, and therefore, the gain of the antenna constituted by the ground conductor plate, the first feeding circuit, and the first radiation circuit board can be improved.

The distance between the ground conductor plate, the first feeding circuit board and the first radiating circuit board is set to about 1/10 of the wavelength of the working frequency, and the first radiating circuit board and the second radiating circuit are used. By setting each interval between the antenna and the second radiating circuit board to be about 1/20 of the used frequency, the gains of the upper-layer antenna and the lower-layer antenna can be made substantially equal, so that the two balanced antennas can be obtained. Is obtained.

[0009]

The present invention will be described below with reference to examples. (Embodiment 1) The planar antenna of this embodiment is a planar antenna for receiving both horizontal and vertical polarized waves, and its basic configuration is the same as that of the conventional planar antenna shown in FIG. In the present embodiment, the first radiating circuit board 3a is made of an aluminum plate having a thickness of 0.2 mm, and is formed by punching slots of 2 mm long × 13 mm wide with a space of 13 mm. The paired slots constitute the radiating element 5a, and the paired slots are vertically and horizontally divided by about 0.85λ.
It is punched and formed in 24 rows and 24 columns at ₀ intervals.

The second radiating circuit board 3b is also made of the same aluminum plate as the first radiating circuit board 3a.
b one side consists 16mm square slot, are punched in 24 rows and 24 columns in each about interval 0.85Ramuda ₀ vertically and horizontally in the radiation circuit board 3b. In addition, each power supply circuit board 2a,
The feed lines 4a and 4b formed in the feeder 2b are formed so as to be electromagnetically coupled to the radiating elements 5a and 5b as shown in FIG. , 3 are each provided with a dielectric layer 6 such as an air layer (or a foamed resin).

Here, ground conductor plate 1, first power supply circuit board 2
a, the antenna constituted by the first radiating circuit board 3a is a lower layer antenna, the first radiating circuit board 3a is a ground conductor plate, and the second
An antenna composed of the feeder circuit board 2b and the second radiating circuit board 3b is an upper antenna, and as shown in FIG. 1, between the ground conductor plate 1 and the first feeder circuit board 2a and the first feeder circuit board 2a, the spacing between the first radiating circuit plate 3a h _1, the first radiating circuit plate 3a, between the second power supply circuit board 2b and second feeding circuit board 2b, between the second radiating circuit plate 3b the interval and h _2.

In FIG. 1, the distance h between the lower antennas is shown.
₁ of about λ _0/10, the distance h ₂ of the upper antenna about lambda
_0/10, when lambda _0/20, is respectively changed to lambda _0/40, each of the peak gain of the lower antenna and the upper antenna were changed as shown in FIG. In the figure, the solid line A indicates the peak gain of the lower layer antenna, and the dotted line B indicates the peak gain of the upper layer antenna. Λ ₀ is the wavelength of the operating frequency, and the frequency range used in the measurement is 10.95 GHz to 1
1.75 GHz.

[0013] peak gain of the lower antenna by a distance h ₂ of about lambda _0/10 to about lambda _0/20 of the upper antenna spacing h ₁ of the lower antenna from the results shown in FIG. 2 as approximately lambda _0/10 Was improved by about 0.3 dB. Still set further about lambda _0/40 apart h _2, the peak gain of the lower antenna can be improved about 0.3dB compared to the case where the distance h ₂ of about λ _0/20, the peak gain of the upper antenna It is evident that it will lower it. Therefore if was about lambda _0/10 apart h ₁ to the peak gain even lower antenna substantially the same as the and the upper antenna improves the peak gain of the lower antenna from this measurement result, the distance h ₂ of about lambda ₀ / It can be seen that setting to 20 is sufficient.

In this embodiment, the interval h _{1 is set} to about λ _0/1.
0, and was the interval h ₂ and about λ _0/20. (Embodiment 2) In this embodiment, as shown in FIG. 3, the shape of the radiating element 5b of the second radiating circuit board 3b is a patch element of 9 mm long × 2.5 mm wide inside a 16 mm-square annular slot. The radiating element 5b is formed by etching using a printed circuit board instead of an aluminum plate as the second radiating circuit board 3b. Interval h
The relationship between ₁ and h ₂ and other configurations are the same as in the first embodiment.

In this embodiment having the above configuration, the same antenna gain as that of the first embodiment was obtained. (Embodiment 3) Although the first and second radiating circuit boards 3a and 3b are formed of aluminum plates in the above-described first embodiment, the radiating circuit boards 3a and 3b are formed of printed circuit boards in this embodiment. The radiating elements 5a and 5b are formed by etching. In the case of this embodiment, the same antenna gain as that of the first embodiment was obtained.

[0016]

According to the first aspect of the present invention, the distance between the first radiating circuit board, the second feeding circuit board, and the second radiating circuit board is set to the ground conductor plate, the first feeding circuit board. , The distance between the first radiating circuit boards is narrower than that of the first radiating circuit board, so that the signal blocked by the second radiating circuit board can be reduced.
There is an effect that the gain of the antenna constituted by the first feeding circuit and the first radiation circuit board can be improved.

According to a second aspect of the present invention, in the first aspect of the present invention, the distance between the ground conductor plate, the first feeder circuit board, and the first radiation circuit board is set to about 1/10 of the wavelength of the operating frequency. By setting each interval between the first radiating circuit board, the second feeding circuit board, and the second radiating circuit board to be about 1/20 of the used frequency, the gain between the upper layer antenna and the lower layer antenna is obtained. Can be made substantially equal, and there is an effect that a balanced gain of both antennas can be obtained.

[Brief description of the drawings]

FIG. 1 is a partially omitted cross-sectional view of a first embodiment of the present invention.

FIG. 2 is a diagram illustrating characteristics of the first embodiment of the present invention.

FIG. 3 is a top view of a part of a radiating element of a second radiating circuit board according to a second embodiment of the present invention, which is partially omitted;

FIG. 4 is an exploded perspective view of the planar antenna with a part omitted.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Ground conductor board 2a 1st feeding circuit board 2b 2nd feeding circuit board 3a 1st radiating circuit board 3b 2nd radiating circuit board 6 Dielectric layer

Claims (2)

(57) [Claims] 1. A first feeder circuit board, a first radiator circuit board, a second feeder circuit board, and a second radiator circuit board are sequentially laminated on a ground conductor plate via a dielectric layer, respectively. In a planar antenna formed such that polarizations of a first feed circuit board and a first radiation circuit board and a second feed circuit board and a second radiation circuit board are orthogonal to each other, the first radiation circuit board is provided. , The distance between the second feeding circuit board and the second radiating circuit board is made smaller than the distance between the ground conductor plate, the first feeding circuit board and the first radiating circuit board. Features a planar antenna. 2. The distance between the ground conductor plate, the first feeding circuit board, and the first radiating circuit board is set to about 1/10 of the wavelength of the operating frequency, and the first radiating circuit board, the second feeding circuit are used. 2. The planar antenna according to claim 1, wherein each interval between the circuit board and the second radiating circuit board is about 1/20 of a used frequency.