JPH10107526A - Portable radio equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a portable radio equipment whose antenna is placed so that the characteristic is not deteriorated due to the effect of a human body. SOLUTION: This radio equipment is made up of a case 13, a radio circuit unit 15 built in the case 13, a speaker 14 connected to the radio circuit unit 15 and placed on one side of the case 13, a linear antenna 12 connecting to the radio circuit unit 15, integrated on the case 13 and placed in the vicinity of the speaker 14, and an antenna cover 11 covering the linear antenna, and the linear antenna 12 is placed with eccentricity from the center of the antenna cover in a direction of the linear antenna 12 parted from the speaker.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a small-sized portable wireless device in which an antenna and a mouthpiece are integrated.

[0002]

2. Description of the Related Art In recent years, portable wireless devices have been reduced in size and thickness. As the name implies, a portable wireless device is a portable wireless device and must be highly portable. For that purpose, small and thin is a very important item.

[0003] Small and thin antennas are one of the technical issues of portable radios that must be rushed forward. Among the components that make up portable radios, the miniaturization of radio circuit units is proceeding at a rapid rate. On the other hand, although the miniaturization of the battery and the antenna is progressing, the speed of the miniaturization of the circuit section is not far. On the other hand, in a portable wireless device, the influence of the human body on the antenna is a problem. The human body has a characteristic of absorbing or scattering radio frequency radio waves. As a result, the radiation characteristics of the antenna are deteriorated by the human body.

[0004] Furthermore, with the recent miniaturization and thinning of wireless devices, the ear tends to be closer to the antenna.
This proximity further worsens the antenna characteristics due to the human body.

FIG. 5 shows the results of measurements performed by the inventors regarding the deterioration of antenna characteristics due to a human body. Hereinafter, the experimental data described in the present specification,
This is a result of an experiment conducted by creating a wireless device model using a portable wireless device having a frequency of 2 GHz as a model.

FIGS. 5A and 5B show vertical polarization patterns in a horizontal plane during a call. FIG. 5A shows a case in which an antenna and a housing which are approximately 10% smaller than those of FIG. 5B are used. As can be seen from the drawing, FIG. 5A shows a deterioration of approximately 8 dB as compared with FIG. Has occurred. As described above, as the size of the wireless device is reduced, the head and the ear approach the antenna, and in some cases, the deterioration of the antenna characteristics becomes extremely large.

[0007] As a method of preventing this deterioration, a method first conceived is to offset the antenna itself and dispose it in a direction away from the ear. However, this method is not very effective. This is because, given the structure of the ear, this approach cannot avoid the proximity of the ear. FIG. 6 is a diagram showing a state of accessibility between the ear and the antenna. In general, the upper end of the ear protrudes outward.
As shown in (a) to (d), the protruding portion of the ear protrudes in the direction of the antenna, resulting in approaching the antenna.

[0008] Unless the upper end of the ear is separated from the antenna, the antenna characteristics cannot be improved. In order to keep the antenna away from the upper end of the ear, it is necessary to mount the antenna at a position sufficiently distant from the ear. However, when the terminal is small and thin, the antenna protrudes largely from the housing of the wireless device.

FIG. 7 shows a method of reducing the proximity of a human body by enlarging a cover for covering an antenna. Generally, an antenna cover is attached to a portable wireless device so that an antenna cannot be easily removed. By increasing the size of the cover, it is possible to avoid the aforementioned proximity between the human body and the antenna.

As is apparent from FIG. 7, when the wireless device housing is small and thin, the antenna becomes larger than the housing and the antenna protrudes from the housing. This is because it is necessary to increase the size of the cover in order to sufficiently obtain the effect of the cover. The above two methods impair the miniaturization of the antenna, and consequently greatly impair the miniaturization and thinning of the entire radio.

[0011]

As described above,
When trying to solve the problem of antennas near the human body, especially the proximity to the ear, which is a problem with portable radios, the antenna is greatly offset from the housing and protrudes from the housing. However, there has been a problem that the thickness of the antenna cover becomes larger than the width of the housing, and as a result, the overall appearance of the wireless device is enlarged. SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a portable wireless device in which antennas are arranged so as not to cause characteristic deterioration due to the influence of a human body.

[0012]

SUMMARY OF THE INVENTION The present invention relates to a housing, a radio circuit unit built in the housing, a speaker disposed on one surface of the housing, and a linear antenna mounted outside the housing. And an antenna cover that covers the linear antenna, wherein the linear antenna is disposed eccentrically from the center of the antenna cover in a direction away from the speaker. .

[0013]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1A is a perspective view illustrating a configuration of a portable wireless device according to an embodiment of the present invention. According to the figure, the portable wireless device includes an antenna cover 11, an antenna 1
2, the housing 13 of the wireless device, the speaker 14 mounted on the front of the housing in the housing 13, the radio circuit unit 15 built in the housing 13, and the lower part of the front of the housing inside the housing 13 And a microphone. The antenna 12 is integrally attached to an upper part of the housing 13 and is covered by the antenna cover 11. The antenna 12 is connected to an antenna terminal of the wireless circuit unit 15 by a connection line 17, and the speaker 14 is similarly connected to an output terminal of the wireless circuit unit 15 by a connection line 18.

In FIG. 1A, the antenna cover 11 is shown in a perspective view so that the state of the internal linear antenna 12 can be understood. FIG. 1B shows an upper surface of the wireless device. As is clear from FIGS. 1A and 1B, the antenna 12 is mounted at a position eccentric from the center axis of the antenna cover 11 in a direction opposite to the position at which the speaker 14 is mounted. That is, the antenna 12 is attached to the housing 13 eccentrically from the center of the antenna cover 11 toward the rear surface of the housing 13.

FIG. 3 is a graph showing the results of measuring the antenna characteristics using the wireless device model shown in FIGS. 2A and 2B based on the portable wireless device shown in FIG. Is shown. According to the wireless device model shown in FIGS. 2A and 2B, the antenna 12 'of the wireless device model is configured by winding the linear element 12a' in a helical shape, similarly to the wireless device of FIG. Have been. In the parameters of each part of the wireless device model, the width of the housing 13 'is 15 mm, the distance from the front surface of the housing 13', that is, the surface on which the speaker 14 'is mounted, to the center of the antenna 12' is 8mm, and the antenna cover 11 ' Is set to 20 mm, the diameter of the antenna cover 11 ′ is set to 9 mm, and the diameter of the antenna 12 ′ is set to 2 mm.

In this experiment, as shown in FIGS. 2 (a) and 2 (b), the wireless device model is equivalent to the position of the center axis of the antenna 12 'by shifting the antenna cover without changing the antenna position. Is set in the same state as eccentric from the center of the antenna cover 11 ′. The shifted distance L is
The surface of the housing 13 ′ on which the speaker 14 ′ is attached is designated as surface A, and the antenna cover 1
3 'is the distance from the closest point to surface A to surface A. FIG. 3 shows a result obtained by examining the relationship between the shift distance of the cover and the gain. As shown in FIG. 4, the gain was a value obtained by averaging the intensity of vertical polarization radiated from the wireless device model held in the attitude during a call in the horizontal plane.

When an experiment is performed to decenter the antenna as in this case, two methods of decentering can be considered. One is to change the position of the cover without changing the position of the antenna, and the other is to change the position of the antenna without changing the position of the cover.

When the method of changing the position of the antenna is used, there are two effects of moving the antenna away from the human body and keeping the ear away from the cover, thereby suppressing deterioration of antenna characteristics due to the human body. On the other hand, if the method of changing the position of the cover is adopted, only the effect of keeping the ear away from the cover will appear.

The purpose of this experiment was to cover the antenna cover 1
In this experiment, a method of changing the position of the antenna cover 11 'without changing the position of the antenna 12' is used because only the effect of keeping the ear away by 1 'is to be examined.

As is clear from the graph of FIG. 3, the measurement results show that the gain of about 4 dB has been improved by shifting the position of the antenna cover 11 '. This is presumed that the proximity of the ear is suppressed by the antenna cover 11 ′, the scattering of radio waves by the ear and the fluctuation of the frequency characteristic of the antenna 12 ′ are reduced, and as a result, the characteristic deterioration of the antenna 12 ′ is reduced. .

Therefore, as shown in FIG. 1, the portable wireless device of the present invention in which the antenna 12 is mounted on the housing 13 so as to be eccentric from the center axis of the antenna cover 11 toward the back surface of the housing 13 is as follows.
The antenna characteristics are improved as compared with the case where the antenna cover and the antenna are coaxially arranged.

[0022]

As described above, by disposing the antenna eccentrically inside the antenna cover,
It is possible to reduce deterioration of antenna characteristics due to a human body without changing the apparent size of the antenna, that is, the size of the antenna cover.

[Brief description of the drawings]

FIG. 1 is a perspective view of a portable wireless device according to an embodiment of the present invention.

FIG. 2 is a perspective view of a wireless device model used for the experiment.

FIG. 3 is a graph showing a relationship between an antenna offset and antenna characteristics obtained by the wireless device model of FIG. 2;

FIG. 4 is a diagram showing a state of measurement using a wireless device model.

FIG. 5 is a view showing a vertically polarized radiation pattern of the PHS terminal when the human head is worn.

FIG. 6 is a diagram showing a state of proximity of the antenna and the ear during a call; FIG.

FIG. 7 is a perspective view of the portable wireless device when the antenna cover is enlarged.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hiroshi Watanabe 3-1-1, Asahigaoka, Hino-shi, Tokyo Inside the Toshiba Hino Plant Co., Ltd. (72) Inventor Hiroyuki Dai 1-3-1, Asahigaoka, Hino-shi, Tokyo Inside Toshiba Hino Plant, Ltd. (72) Inventor Masanobu Shimanuki 21 at 3-1-1 Asahigaoka, Hino-shi, Tokyo Inside (72) Yoshihiro Shimoman, 3-1-1 Asahigaoka, Hino-shi, Tokyo 21 Toshiba Communication Technology Corporation

Claims (2)

[Claims] 1. A housing, a radio circuit unit built in the housing, a speaker disposed on one surface of the housing, a linear antenna mounted outside the housing, and the linear antenna A portable wireless device constituted by an antenna cover that covers the speaker, wherein the linear antenna moves away from the speaker,
A portable wireless device, which is arranged eccentrically from the center of the antenna cover. 2. The portable wireless device according to claim 1, wherein said antenna is mounted eccentrically from a center of said antenna cover on an upper portion of said housing.