JPH0779113A - Antenna - Google Patents

Abstract

PURPOSE:To easily change a resonance frequency with a simple configuration. CONSTITUTION:A radiation metallic plate 1 is arranged almost in parallel with an earth plate 4, one end of the radiation metallic plate 1 is connected to the earth plate 4 by a connection conductor 2 and a surrounding length L of the radiation metallic plate 1 being one of factors for deciding the resonance frequency is changed by short-circuiting an optional position of the earth plate 4 and the radiation metallic plate 1 by a short-circuit pin 5. Thus, when a resonance frequency f0 is changed, it is easily changed by changing the short- circuit position by the short-circuit pin 5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inverted F type antenna which is compact and thin and which can realize wide band characteristics.

[0002]

2. Description of the Related Art From the viewpoint of operability of a portable wireless device, for example, an antenna for a portable wireless device, which is small and thin and has wide band characteristics, is suitable. The inverted F-type antenna is known as one of the antennas having such a structure, and has already been put to practical use as an antenna for portable radios.

FIG. 1 shows an example of the configuration of an inverted F type antenna suitable as such an antenna for portable radio equipment. The radiation metal plate 1 is separated from the main plate 4 by a predetermined distance and is substantially parallel. It is arranged so that. One end of the radiating metal plate 1 is connected to the base plate 4 via the connecting conductor 2. The perimeter L, which is the main determinant of the resonant frequency of the radiating metal plate 1, is selected around λ / 2 (λ is the wavelength of the operating frequency). Here, the perimeter L is the dimension from the feeding point 3 to the connecting conductor 2.

A high frequency signal from the radiating metal plate 1 is obtained via a power supply line (not shown) connected to the power supply point 3. In the inverted F-type antenna having such a configuration, since the radiation metal plate 1 whose perimeter L is selected to be around λ / 2 is arranged close to the base plate 4, it is possible to achieve a small size and a thin shape. It has become.

[0005]

As described above, in the above-mentioned conventional inverted-F type antenna, since the radiation metal plate 1 is arranged close to the ground plate 4, it is possible to achieve a small size and a thin shape. However, since the perimeter length L of the radiation metal plate 1 which is a determining factor of the resonance frequency is fixed, the perimeter length L cannot be changed and the desired resonance frequency cannot be obtained.

In such a case, the desired resonance frequency can be changed by providing the radiation metal plates 1 having different perimeters L in the number corresponding to the desired resonance frequency.
As the number of radiating metal plates 1 provided increases, it becomes impossible to reduce the size and thickness of the antenna.

The present invention has been made in view of such circumstances, and an object thereof is to provide an antenna capable of easily changing the resonance frequency with a simple structure.

[0008]

In order to achieve the above object, the present invention is an antenna in which one end of a radiating metal plate arranged substantially parallel to a ground plane is connected to the ground plane. It is characterized in that any positions of the base plate and the radiation metal plate are short-circuited by a shorting pin.

[0009]

In the antenna of the present invention, the perimeter of the radiating metal plate is a determining factor of the resonance frequency, and the radiating metal plate is surrounded by arranging the arbitrary positions of the ground plate and the radiating metal plate by shorting pins. The length is varied, which gives the desired resonant frequency.

[0010]

Embodiments of the present invention will be described below in detail with reference to the drawings. In the drawings described below, parts common to those in FIG.

FIG. 2 shows an embodiment of the antenna of the present invention, in which the radiation metal plate 1 is separated from the ground plate 4 by a predetermined distance and is arranged substantially in parallel. One end of the radiating metal plate 1 is connected to the base plate 4 via the connecting conductor 2. Short pins 5 are arranged between the radiating metal plate 1 and the base plate 4. The location of the short pin 5 can be changed as described later. In addition, the perimeter L which is one of the determining factors of the resonance frequency in the radiation metal plate 1
Has a dimension from the feeding point 3 to the short pin 5. A high frequency signal from the radiating metal plate 1 is obtained via a coaxial cable 10 which will be described later and is connected to the feeding point 3.

When mounting the short pin 5, for example, the method shown in FIG. 3 is used. That is, the radiation metal plate 1 and the base plate 4 are formed with screw holes 6 and 7 for changing the perimeter L in accordance with the desired resonance frequency.

In addition, the method shown in FIG. 4 is used for power supply. That is, the core wire 11 of the coaxial cable 10, which is a power supply line, is screwed to the power supply point 3 of the radiating metal plate 1 with the screw 12. The shield wire 13 of the coaxial cable 10 is screwed to the main plate 4 side with a screw 14.

Here, how to obtain the resonance frequency of the antenna having the above-mentioned structure will be described with reference to FIG. First, in the figure, the width dimension of the radiation metal plate 1 is L1, and the radiation metal plate 1 is
Is L2, the width dimension of the connecting conductor 2 is W, the width dimension of the radiating metal plate 1 excluding the connecting portion of the connecting conductor 2 is ΔL, and the distance between the radiating metal plate 1 and the base plate 4 is H. ing.

When (L1 / L2) ≤1, the resonance frequency f0 is expressed as f0 = rf1 + (1-r) f2 (1). However, r = W / L1, f1 = 300 / λ1
(GHZ), f2 = 300 / λ2 (MHZ), λ1 = 4
(L2 + H), .lambda.2 = 4 (L1 + L2 + H-W).

As can be seen from the equation (1), the determinants of the resonance frequency f0 are defined by L1, L2, H and W. In the antenna having such a configuration, the resonance frequency can be changed as follows. That is, in this embodiment, the resonance frequency f0
The width dimension W of the connection conductor 2 which is one of the determining factors of is changed equivalently by changing the shorting position by the shorting pin 5.

That is, the positions of the screw holes 6 and 7 formed in the radiation metal plate 1 and the base plate 4 correspond to the desired resonance frequency as described above. Therefore, in order to obtain a desired resonance frequency, the mounting position of the short pin 5 is shifted. When fixing the mounting position of the short pin 5, the screw 8 is inserted into the screw holes 6 and 7 corresponding to the mounting position of the short pin 5, and both ends of the short pin 5 are screwed.

Thus, the dimension of the peripheral length L of the radiation metal plate 1 which is one of the determining factors of the resonance frequency f0 is equivalently changed by changing the shorting position by the shorting pin 5, and the resonance of the above equation (1) is obtained. The frequency f0 can be changed.

As described above, in this embodiment, the radiation metal plate 1 is arranged so as to be substantially parallel to the ground plate 4, and one end side of the radiation metal plate 1 is connected to the ground plate 4 by the connection conductor 2. At the same time, the perimeter length L of the radiation metal plate 1 which is one of the determining factors of the resonance frequency is changed by short-circuiting the arbitrary positions of the base plate 4 and the radiation metal plate 1 by the short pin 5.

Therefore, when the resonance frequency f0 is changed, it can be easily changed by changing the short position of the short pin 5.

[0021]

As described above, according to the antenna of the present invention, the perimeter of the radiating metal plate is the determining factor of the resonance frequency, and the arbitrary positions of the ground plate and the radiating metal plate are connected by the short pin. By changing the circumference of the radiating metal plate by short-circuiting to obtain the desired resonance frequency,
The resonance frequency can be easily changed with a simple configuration.

[Brief description of drawings]

FIG. 1 is a perspective view showing a configuration example of an inverted F-type antenna suitable as a conventional antenna for a portable wireless device.

FIG. 2 is a perspective view showing an embodiment of the antenna of the present invention.

FIG. 3 is a perspective view for explaining a method of attaching the short pin of FIG.

FIG. 4 is a perspective view for explaining a power feeding method in the antenna of FIG.

5 is a perspective view for explaining how to obtain a resonance frequency of the antenna of FIG.

[Explanation of symbols]

 1 Radiant metal plate 2 Connection conductor 3 Feed point 4 Ground plate 5 Short pin

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Eiji Murakoshi Kitashin Sangyo Co., Ltd. 1111-1 Nagasakucho, Hanamigawa-ku, Chiba-shi, Chiba

Claims (1)

[Claims] 1. An antenna in which one end of a radiating metal plate disposed substantially parallel to a ground plate is connected to the ground plate, wherein an arbitrary position between the ground plate and the radiating metal plate is An antenna characterized by being short-circuited by a short pin.