JPH08307126A - Container structure of antenna - Google Patents

Abstract

PURPOSE: To suppress deterioration in a radiation pattern and a gain by connecting a part around a middle part of a radiation element to ground to maximize an input impedance between a 1st radiation element and a shield of a radio equipment when viewing a point around a feeding point. CONSTITUTION: A part around a middle part of a 1st radiation element 21 is connected to ground being a ground conductor 27 which is a ground means of a feeder 25 so as to maximize an input impedance between the 1st radiation element 21 and the ground conductor of the feeder 25 in the case of containing the 1st radiation element 21 in a radio equipment 20. Since a signal current from the grounding side of the feeder 25 is more concentrated onto other radiation elements 22, 23, a current flowing to the radio equipment 20 is suppressed and the effect of radiation when a human body approaches is improved. Even when the signal current from the ground side of the feeder 25 is concentrated on the other radiation elements 22, 23 and the current distribution of the radiation system is close to that of a balanced system, since a part between the radiation element and the shield 24 acts like a balance/unbalance converter, change in the radiation pattern and deterioration in the gain are suppressed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a storage structure for an antenna used in a wireless device such as a mobile phone or a car phone.

[0002]

2. Description of the Related Art FIG. 5 is a schematic view of a "stretchable antenna system and a portable wireless device using the same" disclosed in Japanese Patent Laid-Open No. 2771701. In FIG. 5, 11 is a first radiating element, 12 is a second radiating element,
13 is a third radiating element, 14 is a shield for radio equipment, 1
5 is a feeding line, 16 is a feeding point, 17 is the first radiating element 1
It is a hole for one passage. FIG. 5A shows the first radiating element 11
5B shows a state in which the first radiating element 11 is housed inside the wireless device 10.

FIG. 6 is a sectional view showing a state where the first radiating element 11 is housed inside the radio equipment 10. Figure 5
In (a), the high-frequency power fed to the second radiating element 12 is fed to the first radiating element 11 by electromagnetic field coupling to operate, but in FIG. 5 (b), the second radiating element 12 alone is operated. Only is supposed to work. Third radiating element 13
Has the maximum input impedance between the third radiating element 13 and the shield 14 of the wireless device 10 when viewed from the element end which is not grounded, and the first impedance when viewed from the feeding point 16
The electrical length of ¼ wavelength is set so that the input impedance between the radiating element 11 and the third radiating element 13 is approximately the same as the characteristic impedance of the feed line 15.
Therefore, the current on the ground side mainly flows on the third radiating element 13, so that the current flowing on the shield 14 of the wireless device 10 can be suppressed, and even when the wireless device 10 is held by the human body, radiation due to this Impact on

[0004]

However, in the example disclosed in the above-mentioned JP-A-2-271701,
There are two problems described below when the first radiating element 11 is housed inside the wireless device 10.

1) Since the third radiating element 13 has only one direction, the above-described effect of suppressing the current flowing through the wireless device 10 is not obtained so much, and when the human body approaches, the radiation effect is not so great. Not improved.

2) If the signal current from the ground side of the feed line 15 is concentrated in the third radiating element 13, the radiating system constituted by the second radiating element 12 and the third radiating element 13 is a balanced type. Since the current distribution is close to, and an unbalanced current flows, adverse effects such as a change in radiation pattern and deterioration of gain occur.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above problems and to reduce the deterioration of the radiation pattern and the gain and the deterioration of the characteristics due to the proximity of the human body even when the first radiating element is housed. Another object of the present invention is to provide a wireless device having such an antenna storage structure.

In order to solve the above problems, the present invention provides
First radiating element having an electrical length of / 2 wavelength, 1/4
The second radiating element having an electrical length of wavelength and the third radiating element having an electrical length of ¼ wavelength grounded near the feeding point are provided, and the first radiating element is When the first radiating element can be housed in the wireless device and the first radiating element is pulled out from the wireless device, the high-frequency power supplied to the second radiating element supplies power to the first radiating element by electromagnetic field coupling, When the first radiating element is housed inside the wireless device in the antenna that operates by the second radiating element alone, the first radiating element and the wireless device when viewed from the vicinity of the feeding point The vicinity of the central portion of the first radiating element was grounded so that the input impedance with the shield was maximized.

[0009]

With the above structure, the signal current from the ground side of the power feeding line is concentrated on the other radiating element, so that the current flowing on the radio equipment can be suppressed and the human body is kept close. The radiation effect can be improved. In addition, even if the signal current from the ground side of the feed line concentrates on other radiating elements and the radiating system has a current distribution close to a balanced type, the radiating element and the shield work as a balanced / unbalanced converter. Therefore, it is possible to suppress changes in the radiation pattern and deterioration of the gain.

[0010]

Embodiments of the present invention will be described below with reference to the drawings.

In the figures, the same parts are designated by the same reference numerals.

FIG. 1 shows a wireless device 2 of the first radiating element 21.
The first radiating element 21 and the feeder line 2 when stored in 0
In order to maximize the input impedance with the ground conductor of No. 5, the feeding line 2 is provided near the center of the first radiating element 21.
5 is an example in the case of being grounded to the ground conductor 27 which is the grounding means of No. 5. Reference numeral 22 is a second radiating element, 23 is a third radiating element, and 24 is a shield of a wireless device.

FIG. 2 shows the wireless device 3 of the first radiating element 31.
The first radiating element 31 and the feeding line 3 when stored in 0
5 is an example in which the vicinity of the central portion of the first radiating element 31 is grounded to the ground conductor 37 of the feed line 35 so that the input impedance between the fifth conductor 5 and the ground conductor 37 becomes maximum.
Reference numeral 32 is a second radiating element, 33 is a third radiating element, and 34 is a shield of the wireless device.

In FIG. 3, the first radiating element 41 is used as the wireless device 4.
In the structure housed outside the shield of No. 0, the first radiating element so that the input impedance between the first radiating element 41 and the shield 44 of the wireless device 40 seen from the vicinity of the feeding point becomes maximum. This is an embodiment in which the vicinity of the central portion of 41 is grounded. 42 is the second radiating element,
43 is a third radiating element, 45 is a feed line, and 47 is a ground conductor.

FIG. 4 shows another embodiment relating to a method of grounding the first radiating element 51 to the shield of the wireless device or the ground conductor 54 of the power feeding line when the wireless device 50 is housed,
FIG. 4A shows an embodiment in the case of being grounded by capacitive coupling, and FIG. 4B shows an embodiment in the case of being grounded by inductance coupling. Reference numeral 54 is a shield of the wireless device 50 or a ground conductor of a power supply line, 58 is a capacitive coupling element, and 59 is an inductance coupling element.

Although the first and second radiating elements are both helical elements in the above embodiment,
It goes without saying that the present invention is not limited to this, and can be applied to a radiating element having an arbitrary element shape.

[0017]

As described above, according to the configuration and method of the present invention, 1) the signal current from the ground side of the feed line concentrates on the third radiating element, and therefore flows on the radio equipment. The current can be suppressed, and the effect on radiation when the human body approaches is improved. 2) As described above, the signal current from the ground side of the feed line concentrates on the third radiating element, Even if the radiating system consisting of the radiating element and the third radiating element has a current distribution close to the balanced type, the space between the first radiating element and the shield of the wireless device works as a balanced / unbalanced converter. It is possible to suppress the change of the radiation pattern and the deterioration of the gain.

Therefore, according to the present invention, it is possible to provide a radio device having an antenna housing structure in which the radiation pattern and the gain are not deteriorated even when the first radiating element is housed, and the characteristics are not deteriorated due to the proximity of the human body. it can.

[Brief description of drawings]

1 is an embodiment of the present invention, in which a first radiating element 21 is housed inside a shield 24 of a wireless device,
It shows the case of being grounded.

FIG. 2 is an embodiment of the present invention, in which a first radiating element 31 is housed inside a shield 34 of a wireless device, and a power feeding line 35 is provided.
It shows the case of being grounded to the grounding conductor of.

FIG. 3 is an embodiment of the present invention, in which the first radiating element 41 is housed outside the shield 44 of the wireless device,
It shows the case of being grounded.

FIG. 4 is another embodiment relating to a method of grounding a shield of a wireless device or a feed line to a ground conductor 54 when the first radiating element 51 is housed, and FIG. 4 (a) shows a case of grounding by capacitive coupling. FIG. 4B shows a case of being grounded by inductance coupling.

FIG. 5 is a schematic diagram of a wireless device described in Japanese Patent Application Laid-Open No. 2-271701, which is a conventional technique. FIG. 5A shows the first radiating element 11 in a stretched state, and FIG. 5B shows the housed state.

FIG. 6 is a cross-sectional view of a state where the first radiating element 11 is housed inside the wireless device.

[Explanation of symbols]

Reference Signs List 10 wireless device 11 first radiating element 12 second radiating element 13 third radiating element 14 shield of wireless device 15 feeding line 16 feeding point 17 hole for passing first radiating element 20 wireless device 21 first radiating Element 22 Second radiating element 23 Third radiating element 24 Shield of wireless device 25 Feed line 27 Ground conductor 30 Wireless device 31 First radiating element 32 Second radiating element 33 Third radiating element 34 Shield of wireless device 35 Feed Line 37 Ground Conductor 40 Radio Equipment 41 First Radiating Element 42 Second Radiating Element 43 Third Radiating Element 44 Shield of Radio Equipment 45 Feed Line 47 Ground Conductor 50 Radio Equipment 51 First Radiating Element 54 Radio Equipment Grounding conductor of shield or feed line 58 Capacitive coupling element 59 Inductance coupling element

Claims (1)

[Claims] 1. A first radiating element having an electrical length of ½ wavelength, a second radiating element having an electrical length of ¼ wavelength, and a grounding element 1 near a feeding point. A third radiating element having an electrical length of / 4 wavelength, the first radiating element can be housed inside the wireless device, and when the first radiating element is pulled out from the wireless device, the second radiating element is When the first radiating element is housed, the high-frequency power fed to the radiating element is fed to the first radiating element by electromagnetic field coupling,
Of the radiating element alone, the input impedance between the first radiating element and the shield of the wireless device when viewed from the vicinity of the feeding point is maximized when the first radiating element is housed inside the wireless device. The antenna storage structure is characterized in that the vicinity of the central portion of the first radiating element is grounded so that