JPH06303163A - Portable radio equipment - Google Patents

Abstract

PURPOSE:To attain excellent mount of a plane antenna built in the equipment by connecting a feeder to the antenna to a predetermined position of a metallic case of the portable radio equipment. CONSTITUTION:An inverted F type antenna 1 is installed in a metallic case 2 and consists of a radiation conductor 11, a dielectric base 12 and a ground conductor 13 and a throughhole 14 short-circuiting the conductors 11, 13. The case 12 with the antenna 1 mounted thereon is arranged closely to the ground conductor 13 of the antenna 1 and connected electrically thereto and the surface of the case 12 also acts as a ground conductor of the antenna. Then the end of the feeder 23 led from a throughhole 2a of a side face of the metallic case 2 is soldered to a predetermined position of the side face of the case 2 by solder 33 to execute feeding to the antenna 1. The position of soldering is a position where impedance is well matched. As a result, it is not required to solder the feeder to the radiation conductor 11 of the antenna 1, and the profile of the antenna is made thin and the mount of the plane antenna built in the portable radio equipment is executed in an excellent way.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a portable wireless device having a planar antenna built therein.

[0002]

2. Description of the Related Art As a conventional portable wireless device such as a portable telephone, there is a portable wireless device incorporating a planar antenna. Here, as an example thereof, FIG. 4 shows a portable wireless device incorporating an inverted F antenna. In FIG. 4, reference numeral 1 indicates an inverted F antenna, and the inverted F antenna 1 is installed on the surface of a metal housing 2. ing. The metal housing 2 is a non-metal housing (that is, a case made of synthetic resin or the like) that constitutes an outer case of the portable wireless device.
A circuit as a wireless device is formed on a circuit board (not shown) which is disposed inside and is housed in the metal housing 2.

The inverted F antenna 1 is a radiation conductor 1
1, a through hole 1 which is composed of a dielectric substrate 12 and a ground conductor 13 and short-circuits the radiation conductor 11 and the ground conductor 13
4 (or short-circuit conductor pin) is provided. Further, the metal casing 2 in which the inverted F antenna 1 is installed is in close contact with and electrically connected to the ground conductor 13 of the inverted F antenna 1, and the surface of the metal casing 2 is also grounded by the inverted F antenna. It functions as a conductor.

Conventionally, in the inverted-F antenna 1 having such a structure, power is fed to the antenna through a through hole 15 penetrating the radiation conductor 11, the dielectric substrate 12, and the ground conductor 13, as shown in FIG. 5, for example. Open the feed line 21 through the through hole 15 and solder 31 to the radiation conductor 11 at one end of the feed line 21.
Solder on the surface of. Then, the other end of the power supply line 21 is connected to a predetermined circuit inside the metal housing 2.

FIG. 6 shows another configuration for power feeding.
As shown in FIG. 3, the inverted F antenna 1 is not provided with a hole, and the end of the power supply line 22 pulled out from the through hole 2a on the side surface of the metal housing 2 is soldered to the radiation conductor 11 on the upper surface of the antenna with solder 32. Is being done.

[0006]

With any of the configurations shown in FIGS. 5 and 6, when a portable radio device is actually manufactured,
Since the antenna 1 must be attached to the metal housing 2 and then the feeder line must be soldered, there is no degree of freedom in the manufacturing process.
Further, in order to remove the antenna during maintenance of the inside of the metal housing, the solder 31, 32 applied to the antenna is used.
Had to get rid of. Further, since the solder 31 or 32 is put on the radiating conductor 11 on the upper surface of the antenna, the thickness of the inverted F antenna 1 is correspondingly increased, and a case such as a synthetic resin in which the metal housing 2 is built in must be increased in size. This was an obstacle to the miniaturization of portable radios.

In view of these points, it is an object of the present invention to make it possible to favorably mount a planar antenna incorporated in a portable wireless device.

[0008]

According to the present invention, as shown in FIG. 1, for example, a plane antenna 1 composed of a radiation conductor 11, a dielectric substrate 12 and a ground conductor 13 and a metal casing closely attached to the ground conductor 13 are provided. 2 is a portable wireless device having a power supply line to an antenna connected to a predetermined portion of the metal housing 2.

In this case, the plane antenna is an inverted F antenna.

[0010]

According to the structure of the present invention, it is not necessary to solder the feeder line to the radiation conductor of the antenna, and the antenna can be made thinner accordingly.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. In FIGS. 1 to 3, FIGS.
Parts corresponding to those in FIG. 6 are designated by the same reference numerals, and detailed description thereof will be omitted.

This example is applied to a portable wireless device that transmits and receives signals using a frequency of 900 MHz band, and is configured as shown in FIG. Referring to FIG. 1, the inverted F antenna 1 of this example is installed in a metal housing 2. The inverted F antenna 1 includes a radiation conductor 11, a dielectric substrate 12, and a ground conductor 13, and is formed of a through hole 14 (or a short-circuit conductor pin) that short-circuits the radiation conductor 11 and the ground conductor 13. The metal casing 2 in which the inverted F antenna 1 is installed is the ground conductor 1 of the inverted F antenna 1.
It is electrically connected by arranging closely with 3.
The surface of the metal housing 2 also functions as the ground conductor of the inverted F antenna.

In the present embodiment, the end portion of the power supply line 22 drawn out from the through hole 2a on the side surface of the metal housing 2 is soldered to a predetermined position on the side surface of the metal housing 2 with the solder 33, and the antenna Power is supplied to 1. In this case, this soldering position is a position where impedance matching can be achieved. This point will be described later.

The other parts are constructed in the same manner as the portable radio device shown in FIG. 4 as a conventional example.

Here, the power feeding structure of the antenna 1 of the portable wireless device of this example will be described. The structure of this example should be regarded as a ground of zero potential.
Is a method of supplying power to. This is because, for example, in a 900 MHz band portable wireless device or the like, the side length of the metal casing is smaller than one wavelength with respect to the propagation wavelength, and the metal casing cannot be regarded as a sufficient ground. Therefore, a current also flows on the metal case, and as a result, a phenomenon occurs in which the ground is not at zero potential and the impedance changes depending on the position on the metal case. In this example, paying attention to this phenomenon,
Matching is performed by feeding power not to the antenna but to the point where the impedance of the power feeding system on the metal housing 2 becomes equal.

Here, the characteristics of the antenna of this example will be shown. For example, the length in the long side direction is 140 mm, and the length in the short side direction is 40 mm.
The metal plate having a size of 1 mm and a thickness of 1 mm is used as the metal housing 2 and the inverse F antenna 1 resonating at 936 MHz is installed at the end of the metal housing 2 and the outer conductor of the semi-rigid cable is connected to the inverse F antenna 1 It is assumed that the metal housing 2 is soldered directly under the through hole 14 and the true line of the semi-rigid cable is soldered to the side surface of the metal housing 2 offset by 24 mm in the long side direction. The input impedance characteristic at this time is shown in FIG. Also,
FIG. 3 shows a radiation pattern in a horizontal plane when the metal housing is set upright at the resonance frequency. As can be seen from these figures, the radiation characteristics such as bandwidth and gain have almost the same values as those of the conventional inverted F antenna.

In the above embodiment, the power supply line is soldered to the side surface of the metal housing, but it may be soldered to another surface. Further, in the above-mentioned embodiment, the invention is applied to the plane antenna composed of the inverted F antenna.
Of course, it can be applied to other similar planar antennas.

[0018]

According to the present invention, in a portable radio having a built-in planar antenna, the radiation conductor of the planar antenna is not fed, but the metal housing is fed with the following effects. 1. When actually manufacturing, it is not necessary to directly solder the metal casing and the antenna, and the degree of freedom in the manufacturing process is increased. 2. When removing the antenna for maintenance inside the metal housing, it is not necessary to remove the solder of the antenna, and the antenna can be easily removed. 3. Since the soldering is not performed on the antenna upper surface, it is not necessary to increase the clearance between the case and the antenna arranged outside the antenna, and the portable device can be downsized accordingly.

[Brief description of drawings]

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

FIG. 2 is a characteristic diagram showing an input impedance of an antenna according to an embodiment of the present invention.

FIG. 3 is a characteristic diagram showing a radiation pattern of an antenna according to an embodiment of the present invention.

FIG. 4 is a perspective view showing an inverted F antenna installed in a conventional portable wireless device or the like.

FIG. 5 is a perspective view showing an example of a conventional feed structure for an inverted F antenna.

FIG. 6 is a perspective view showing another example of a conventional feed structure for an inverted F antenna.

[Explanation of symbols]

 1 Inverted-F Antenna 2 Metal Housing 11 Radiating Conductor 12 Dielectric Substrate 13 Grounding Conductor 14 Through Hole 23 Feeding Wire 33 Soldering Section

Claims (2)

[Claims] 1. A portable wireless device having a flat antenna composed of a radiation conductor, a dielectric substrate, and a ground conductor, and a metal casing in close contact with the ground conductor. A portable wireless device characterized by connecting electric wires. 2. The portable wireless device according to claim 1, wherein the planar antenna is an inverted F antenna.