JPH07297624A - Plane antenna - Google Patents

Abstract

PURPOSE:To reduce the restriction for layout of the internal parts of a radio equipment by supplying the electric power to a resonance conductor plate from a feeding conductor plate through the capacitive coupling. CONSTITUTION:A resonance conductor plate 2 having its circumferential length equal to about 1/2 working radio wave is placed at the upper part of a ground conductor plate 1. A conductor 4 consists of both plates 1 and 2 connected together and positioned at the edge of the plate 2. A feeding conductor plate 6 having a feeding part 3 is placed almost in parallel to the plate 1 at a place near the edge side 7 of the plate 2 set opposite to the conductor 4. As the voltage is high in a resonance mode at the side 7, the electric field generated between the side 7 and the plate 1 is large and two sides of the side 7 are capacitively coupled to two sides of the plate 6. This coupling value is set by the distance D between both plates 2 and 6 and the distance L between the coupled sides.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a planar antenna built in a housing of a radio device, and more particularly to a planar antenna having a characteristic power feeding structure.

[0002]

2. Description of the Related Art Inverted F antenna, which is a short-circuited one-sided plane antenna, is used as a plane antenna built in the casing of a radio such as a mobile phone
A large number of antennas are used, and FIGS. 4A and 4B are schematic views of the inverted F antenna. (A) is a side view of an inverted F-shaped antenna, and (b) is a top view of the inverted F-shaped antenna. At the upper part of the conductor plate 1 for ground, the perimeter is about 1 / wavelength of the used radio wave.
The resonance conductor plate 2, which is 2, is arranged. In addition, a dielectric layer may be provided between the ground conductor plate 1 and the resonance conductor plate 2 in order to reduce the peripheral length. The resonance conductor plate 2 and the ground conductor plate 1 are connected by the conductor 4, and the conductor 4 is located at the edge of the resonance conductor plate 2. As shown in FIG. 4, the resonance conductor plate 2, the ground conductor plate 1, the conductor 4, and the feeding portion 3 have an inverted F shape structure, and the resonance conductor plate 2 resonates at a corner 5 facing the conductor 4. Sometimes the voltage is highest. Further, since the voltage of the edge of the resonance conductor plate 2 to which the conductor 4 is connected becomes low at the time of resonance, the corner 5 of the resonance conductor plate 2 facing the conductor 4 and the edge of the resonance conductor plate 2 to which the conductor 4 is connected. By supplying power between the resonance conductor plate 2 and the ground conductor plate 1, the impedance matching between the antenna and the wireless device can be achieved.

[0003]

However, the impedance of the radio is often designed to be 50 ohms.
In the case of the inverted F-shaped antenna shown in FIG. 4, the voltage at the corner 5 of the resonance conductor plate 2 facing the conductor 4 is very high at the time of resonance, and therefore the position of the feeding portion 3 is close to the conductor 4. With the thinning of wireless devices such as mobile phones in recent years, it is necessary to shorten the distance between the resonance conductor plate 2 and the ground conductor plate 1, so that the position of the power feeding unit 3 is closer to the conductor 4. In general, the position of the power feeding portion 3 is set to a position several mm from the conductor 4 at 800 MHz. Therefore, the power feeding unit 3
If the positioning is not performed accurately, impedance mismatch will occur and the gain of the antenna will decrease. When the inverted F-shaped antenna is incorporated in the radio casing, the conductor 4 is often arranged above the radio casing so as not to interfere with the radiation from the conductor 4 as in Japanese Patent Publication No. 63-8655. Since the position of the power feeding unit 3 is inevitably limited to a certain position, it is necessary to place restrictions on the layout of components and the like that obstruct the wiring of the coaxial cable for guiding the high-frequency signal from the power feeding unit 3 into the wireless device. There was a problem.

It is an object of the present invention to provide a planar antenna which can reduce layout restrictions of components inside a radio.

[0005]

In order to solve the above problems, the present invention provides a resonance conductor plate 2 having a perimeter of about 1/2 the wavelength of a radio wave used, as shown in FIG. A plane antenna provided with a conductor plate for ground 1 arranged substantially in parallel with the conductor plate for ground 1, and connecting one edge portion of the conductor plate for resonance 2 and the conductor plate for ground 1 with a conductor 4 for resonance. A feeding conductor plate 6 having a feeding portion 3 is arranged in parallel with the ground conductor plate 1 in the vicinity of an edge 7 facing the edge portion connected by the conductor 4 among the plurality of edges of the conductor plate 2. Then, the plane antenna is characterized in that the resonance conductor plate 2 is fed from the feed conductor plate 6 by capacitive coupling.

[0006]

According to the planar antenna of the present invention, the resonance conductor plate 2 has the power feeding portion 3 in the vicinity of the edge 7 facing the edge portion connected by the conductor 4 and substantially parallel to the ground conductor plate 1. By arranging the conductor plate 6 for use, the position of the power feeding portion 3 can be arbitrarily set along the edge 7, so that a coaxial cable for guiding a high-frequency signal from the antenna to the inside of the wireless device in a high-density mobile phone or the like. By setting the power supply unit 3 to the wiring of the cable in the part where there is a gap such as parts inside the radio,
There are few restrictions on the layout of components inside the radio device, and it is possible to easily route the coaxial cable.

[0007]

Embodiments of the present invention will be described in detail below with reference to the drawings. 1 (a) and 1 (b) are views showing a first embodiment of a planar antenna of the present invention, in which the same parts are designated by the same reference numerals. (A) is a side view of the planar antenna,
(B) is a top view of a planar antenna. Next, the operation in such a configuration will be described. A resonance conductor plate 2 having a perimeter of about ½ of the wavelength of the radio wave used is arranged on the ground conductor plate 1. In addition, a dielectric layer may be provided in the space between the ground conductor plate 1 and the resonance conductor plate 2 in order to reduce the peripheral length. The conductor 4 connects the two conductor plates and is located at the edge of the resonance conductor plate 2. In the power feeding portion 3, a power feeding conductive plate 6 having the power feeding portion 3 is arranged substantially parallel to the ground conductive plate 1 in the vicinity of the end side 7 of the resonance conductive plate 2 facing the conductor 4.

Next, the operation in such a configuration will be described. In FIG. 1, since the voltage of the end side 7 of the resonance conductor plate 2 facing the conductor 4 is high at the time of resonance, the electric field between the end side 7 and the ground conductor plate 1 is large, and the power is supplied near the end side 7. By disposing the conductor plate 6 for power supply, the two sides of the end side 7 and the two sides of the power supply conductor plate 6 are capacitively coupled. The amount of coupling can be set by the distance D between the resonance conductor plate 2 and the power feeding conductor plate 6 and the distance L between the connected sides, and the coupling capacitance increases by shortening the distance D or increasing the distance L. Therefore, it is easy to match the impedance of the antenna to the impedance of the radio device of 50 ohms.

2A and 2B are views showing a second embodiment in which a feeding conductor plate 6 is arranged at a corner 5 of the resonance conductor plate 2 facing the conductor 4, and FIG. 2A is a plan view. Side view of the antenna,
(B) is a top view of a planar antenna. Since the voltage of the corner 5 facing the conductor 4 is the highest at resonance, the coupling capacitance between the corner 5 and the ground conductor plate 1 is large, so that the distance D can be separated.

FIGS. 3 (a) and 3 (b) are views showing a third embodiment in which a power feeding conductor plate 6 is arranged between the resonance conductor plate 2 and the ground conductor plate 1, and FIG. The side view of an antenna and (b) are the top views of a plane antenna. Since the power supply conductor plate 6 and the resonance conductor plate 2 are arranged in parallel,
The coupling between the resonance conductor plate 2 and the feeding conductor plate 6 is very large, and the area of the feeding conductor plate 6 can be small.

Since the electrical length is affected by the structure and materials of the casing and the power feeding portion, the conductive parts, etc., the lengths around the resonance conductor plate 2 and the power feeding conductor plate 6 are finely adjusted. Determined by

As described above, according to the configuration of the present invention, the feeding conductor plate 6 having the feeding portion 3 is provided in the vicinity of the end side 7 of the resonance conductor plate 2 facing the conductor 4 and the grounding conductor plate 1 is provided. Since the position of the power feeding part 3 can be arbitrarily set along the end side 7 by arranging the power feeding part 3 substantially in parallel with the power feeding part 3, the coaxial cable for guiding the high frequency signal from the antenna to the inside of the wireless device in the high density cellular phone or the like. By setting the wiring of the power feeding unit 3 in a portion with a gap such as a component in the wireless device,
There are few restrictions on the layout of components inside the radio device, and it is possible to easily route the coaxial cable. In addition, the impedance of the antenna is 50
You can easily adjust to ohms.

[0013]

According to the planar antenna of the present invention, it is possible to reduce restrictions on the layout of components inside the radio device.

[Brief description of drawings]

FIG. 1 is a first embodiment showing a planar antenna of the present invention,
(A) is a side view of a plane antenna, (b) is a top view of a plane antenna.

FIG. 2 is a second embodiment showing the planar antenna of the present invention,
(A) is a side view of a plane antenna, (b) is a top view of a plane antenna.

FIG. 3 is a third embodiment showing the planar antenna of the present invention,
(A) is a side view of a plane antenna, (b) is a top view of a plane antenna.

FIG. 4 is a schematic view of a conventional inverted F-shaped antenna, (a) is a side view of the inverted F-shaped antenna, and (b) is a top view of the inverted F-shaped antenna.

[Explanation of symbols]

 1 conductor plate for ground 2 conductor plate for resonance 3 power supply section 4 conductor 5 corner 6 power supply conductor plate 7 edge

Claims (1)

[Claims] 1. A resonance conductor plate having a perimeter of about half the wavelength of a radio wave used, and a ground conductor plate arranged substantially parallel to the resonance conductor plate. In a planar antenna formed by conductor-connecting one edge portion and a conductor plate for ground, a power feeding portion having a feeding portion near one of the plurality of end portions of the resonance conductor plate facing the edge portion. A planar antenna, in which a conductor plate for use in the ground is arranged substantially parallel to the conductor plate for ground, and power is supplied to the conductor plate for resonance from the conductor plate for power supply by capacitive coupling.