JP2001339226A - Antenna system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To overcome the problem such that a matching circuit is needed and then the gain degreases as compared with the gain of a dielectric antenna element since a conventional antenna system can not be lowered in resonance frequency sufficiently when miniaturized and mounted. SOLUTION: A plate type auxiliary element 3 which is conductive is fitted to an antenna element having an electrode pattern 2 formed on a dielectric 1. A feed point 5 is connected to the electrode pattern 2. Consequently, the resonance frequency of the antenna can be lowered by the effect of wavelength shortening obtained by using the dielectric element and the effect of the auxiliary element 3 which is connected, and the antenna characteristics can be improved while a limited mount space is effectively used.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an antenna device, and more particularly, to an antenna device for a portable radio having an electrode pattern formed on a dielectric.

[0002]

2. Description of the Related Art As portable radios have become smaller, the mounting space for a receiving antenna has been reduced, and dielectric antenna elements having an electrode pattern as shown in FIG. 5 have been used. This is because the electrode pattern 2 has a zigzag shape on one surface of the rectangular parallelepiped dielectric 1 and covers almost the entire surface except for a part of the upper surface of the dielectric 1, thereby providing an inductance component and providing a dielectric component. 1 also has the effect of shortening the wavelength. In FIG. 5, reference numeral 5 denotes a feeding point.

[0003] Thus, this conventional antenna device is
The size can be reduced to about λ / 40 (λ is the wavelength of a received radio wave) on one side, and is mounted on a printed circuit board and operates as an antenna like other electronic components.

On the other hand, the conventional antenna device shown in FIG.
In the meander-shaped inverted-F antenna, one end of the antenna element 8 is forked, one is grounded, and the other is connected to the feeding point 5. Further, the conventional antenna device shown in FIG. 7 is an inverted L antenna configured in a meander shape, and one end of an antenna element 8 is connected to a feeding point 5. It is known that these inverted F antennas and inverted L antennas can also be reduced in size.

[0005]

However, in the conventional antenna device shown in FIG. 5, for example, as shown in FIG.
This antenna device is mounted on a printed board of a portable wireless device having a housing case 11 made of metal by other electronic components 1.
In the case where the electronic component 10 is mounted together with 0, a gain deterioration of about 8 dB occurs as compared with the case where the electronic component 10 is not provided.

In the conventional antenna device shown in FIGS. 6 and 7, if the antenna device is miniaturized to a mountable size of about λ / 15, the resonance frequency cannot be sufficiently reduced. A matching circuit using a coil is required, and as a result, when used in place of the dielectric antenna element, the gain is reduced by about 2 dB compared to the gain of the dielectric antenna element when no electronic components are mounted around the antenna. Resulting in. This is because the resonance frequency cannot be sufficiently reduced even in the meandering shape within the limited mounting space, and the resonance frequency is lowered by the matching circuit, and a large loss occurs here.

[0007] The present invention has been made in view of the above points,
An object of the present invention is to provide an antenna device capable of improving antenna gain.

Another object of the present invention is to provide an antenna device capable of effectively utilizing a limited mounting space.

[0009]

According to the present invention, in order to achieve the above object, in an antenna device having an electrode pattern formed on a conductor, a conductive auxiliary element having one end connected to a part of the electrode pattern is provided. And a power supply point for supplying power to the electrode pattern.

According to the present invention, the antenna length can be secured and the resonance frequency of the antenna can be reduced by the effect of shortening the wavelength of the dielectric and the effect of connecting the conductive auxiliary element. Further, the radiation characteristics of the antenna can be increased without changing the size of the dielectric in order to improve the antenna characteristics.

Here, the conductive auxiliary element is desirably plate-shaped. Further, the conductive auxiliary element described above may be such that an insulating material is plated with metal. The shape of the auxiliary element can be finely varied.

According to another aspect of the present invention, a power supply point is provided on a substrate, and the other end of the conductive auxiliary element is provided on an inner wall of a housing case for housing the substrate and the conductor. It is characterized by being attached. According to the present invention, the mounting space on the substrate can be only the mounting space for the dielectric.

Here, according to the present invention, one end of the electrode pattern is connected to a feeding point and can operate as an inverted L antenna. Also, the end of the electrode pattern is bifurcated and one is connected to the feeding point. , The other is grounded and can operate as an inverted-F antenna.

[0014]

Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view of an embodiment of the antenna device according to the present invention, and FIG. 2 is a vertical sectional side view of the embodiment when the antenna device according to the present invention is housed in a housing. In both figures, the same components are denoted by the same reference numerals.

As shown in FIG. 1, the antenna device of this embodiment includes a dielectric 1, an electrode pattern 2, and a conductive plate-shaped auxiliary element 3. Electrode pattern 2
Is formed by metal plating on the front and top surfaces of a rectangular parallelepiped dielectric 1 as in the conventional device.
From the power supply point 5 on the substrate 6 to the connection point 4 with the conductive plate-shaped auxiliary element 3. The conductive plate-shaped auxiliary element 3 is a conductor, and is connected to the electrode pattern 2 formed on the upper surface of the dielectric 1 via the connection point 4. In the antenna device of the present embodiment, power is supplied to the electrode pattern 2 of the dielectric 1. The housing case 7 houses the dielectric 1, and the conductive plate-shaped auxiliary element 3 is attached to the upper inner wall thereof.

As shown by 9 in FIG. 3, the antenna device was mounted on a portable radio having an electronic component 10 mounted inside a housing case 11 made of metal, and the gain was measured. It was confirmed that a value equivalent to the gain of the dielectric antenna element when the electronic component 10 was not mounted in the periphery was obtained.

This is because, as shown in FIG. 2, by connecting a conductive plate-shaped auxiliary element 3 to the dielectric 1, the antenna apparatus of the present embodiment operates as an inverted L antenna, but the dielectric antenna This is considered to be because the use of the element provided an appropriate wavelength shortening effect that cannot be obtained with the conventional inverted L antenna shown in FIG. 7, thereby achieving a significant gain improvement.

Also, since the resonance frequency of the antenna is reduced by the effect of the conductive plate-shaped auxiliary element 3 connected to the wavelength shortening effect of the dielectric, the loss due to the matching circuit can be reduced. It has been confirmed that this gain improving effect exists even when the case is not made of metal. Further, in this embodiment, by connecting the conductive plate-shaped auxiliary element 3 to the electrode pattern 2, the substrate 6
The antenna gain can be improved since the distance from the (ground) is large and the influence of other mounted components is small.

In order to improve the gain using only the dielectric antenna element, it is necessary to increase the size of the dielectric element. In this embodiment, however, as shown in FIG. Since the plate-shaped auxiliary element 3 is attached, the mounting space on the substrate 6 is only the mounting space for the dielectric 1, and the space between the substrate 6 and the housing case 7 is used. Conductive plate-shaped auxiliary element 3
And there is no need to increase the mounting space on the substrate 6.

As described above, in this embodiment, by attaching the electrode pattern 22 formed on the dielectric 1 and the conductive plate-shaped auxiliary element 3, it is possible to obtain a small size and high gain.

Next, another embodiment of the present invention will be described. FIG. 4 is a perspective view of another embodiment of the antenna device according to the present invention. The embodiment shown in FIG. 1 is operated as an inverted L antenna.
As shown in FIG. 4, a part of the electrode pattern 2 is branched and grounded via the electrode pattern portion 12, thereby operating as an inverted F antenna. This embodiment has the same effect as the above embodiment.

The present invention is not limited to the above-described embodiment. For example, the conductive plate-shaped auxiliary element 3 is a conductor, but has a structure in which an insulator is plated with metal. You can also.

[0023]

As described above, according to the present invention,
Due to the effect of shortening the wavelength of the dielectric and the effect of connecting the conductive auxiliary element, the antenna length can be secured and the resonance frequency of the antenna can be reduced, so the loss due to the matching circuit can be reduced and the antenna gain can be greatly improved it can.

Further, according to the present invention, the radiation characteristics of the antenna can be increased without changing the size of the dielectric in order to improve the antenna characteristics, and the shape of the auxiliary element can be finely changed. As a result, the limited mounting space can be effectively utilized.

Further, according to the present invention, the power supply point is provided on the substrate, and the other end of the conductive auxiliary element is attached to the inner wall of the housing case accommodating the substrate and the conductor. Since the upper mounting space can be limited to only the dielectric mounting space, it is possible to prevent an increase in the shape of the entire device without increasing the mounting space on the substrate.

[Brief description of the drawings]

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

FIG. 2 is a longitudinal sectional view of one embodiment when the present invention is housed in a housing case.

FIG. 3 is a perspective view of an example of a form radio device on which the device of the present invention is mounted.

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

FIG. 5 is a perspective view of a conventional example.

FIG. 6 is a configuration diagram of another example of the related art.

FIG. 7 is a configuration diagram of still another conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Dielectric 2 Electrode pattern 3 Conductive plate-shaped auxiliary element 4 Connection point 5 Feeding point 6 Substrate 7 Housing case 9 Dielectric antenna element 10 Electronic component 11 Housing case made of metal 12 Electrode pattern part

Claims (6)

[Claims] 1. An antenna device having an electrode pattern formed on a conductor, comprising: a conductive auxiliary element having one end connected to a part of the electrode pattern; and a feeding point for feeding power to the electrode pattern. An antenna device characterized by the above-mentioned. 2. The antenna device according to claim 1, wherein the auxiliary element has a plate shape. 3. The antenna device according to claim 1, wherein the auxiliary element is formed by plating an insulator with metal. 4. The power supply point is provided on a substrate,
The antenna device according to claim 1, wherein the other end of the conductive auxiliary element is attached to an inner wall of a housing case that houses the substrate and the conductor. 5. The antenna device according to claim 1, wherein one end of the electrode pattern is connected to the feeding point, and operates as an inverted L antenna. 6. The antenna device according to claim 1, wherein an end of the electrode pattern is bifurcated, one is connected to the feeding point, and the other is grounded to operate as an inverted F antenna. .