JP2006304072A - Portable radio apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a portable radio apparatus for reducing a local average SAR and acquiring higher antenna performance. <P>SOLUTION: Opening and closing states of a casing are detected by a casing opening/closing means 6. A first antenna 4 is connected with a radio circuit 24 in a state that the casing is opened. The resonance frequency of a second antenna 5 is adjusted to a transmitting frequency band. In a state that the casing is closed, the resonance frequency of the second antenna 5 is adjusted to the transmitting frequency and a receiving frequency and the second antenna 5 is connected with the radio circuit 24. Consequently, an antenna current can be dispersed when the casing is opened. Moreover, the local average SAR can also be reduced, and a higher antenna gain can be obtained when the casing is closed. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an openable and foldable portable wireless device in which an upper housing and a lower housing are connected by a hinge, and in particular, can reduce local average SAR (Specific Absorption Rates) and have a high antenna gain. The present invention relates to a portable wireless device that can have

  Currently, mobile wireless devices such as mobile phones are widely used. For example, foldable mobile phones having a mechanism that can be opened and closed by connecting an upper housing and a lower housing with a hinge are widely used. . This foldable mobile phone generally has two states, an open state and a closed state, and has the convenience that the display screen to be viewed can be enlarged in the open state (open state). In the state of use in a closed state (closed state), it has two advantages of portability, that is, a compact shape.

By the way, in recent years, the user's interest in the local average SAR has increased, and there is a tendency to select a mobile phone having a lower local average SAR as an index for selecting the mobile phone. For these reasons, it is desirable for the mobile phone to have a low local average SAR. As a conventional means for keeping the local average SAR low, for example, a conductive metal element having one open end is connected (grounded) to the ground in the vicinity of the feed point of the unbalanced feed antenna, and the conductive metal element is connected at a desired frequency. A method of setting the resonance length is known.
Usually, this conductive metal element is disposed on the housing (outside) surface opposite to the housing (inside) surface having the sound hole of the receiving part close to the human body. With this configuration, the current from the feeding point flows through the conductive metal element, and the current flowing through the casing surface close to the human body can be reduced, so that the local average SAR can be reduced (see, for example, Patent Document 1). ).

  As another means for reducing the local average SAR, the shield case of the upper casing having the receiving part by dividing the current at the feeding point is used as the antenna element (first antenna), and the ground substrate of the lower casing is used. In a structure in which power is supplied to the antenna element via a flexible cable, a method of connecting a rod antenna (second antenna) to a power supply unit is known (for example, see Patent Document 2).

Hereinafter, a conventional method for reducing the local average SAR shown in Patent Document 1 will be described with reference to FIGS. 4 and 5. 4 shows a state in which the casing of the folding cellular phone is opened, and FIG. 5 shows a state in which the casing is closed.
The foldable mobile phone 100 detects a conductive metal element (not shown) having one end opened in the vicinity of the hinge portion 103 that supports the upper housing 101 and the lower housing 102 so as to be freely opened and closed, and the opening and closing of the housing. Case opening / closing detection means 104A and 104B are arranged.
When the case opening / closing detection means 104A, 104B detects that the upper case 101 and the lower case 102 are opened, the first matching circuit 106 connected to the first antenna 105 is shown in FIG. Are connected to the radio circuit 108 via the antenna switching circuit 107. On the other hand, the second matching circuit 110 connected to the second antenna 109 is connected to the ground pattern of the circuit board 111 via the switching circuit 112. When it is detected that the upper casing 101 and the lower casing 102 are closed, the second antenna 109 is connected via the second matching circuit 110, the switching circuit 112, and the antenna switching circuit 107, as shown in FIG. Connected to the radio circuit 108.

As described above, in the foldable mobile phone 100 shown in FIGS. 4 and 5, when the upper casing 101 and the lower casing 102 are opened, the antenna current of the first antenna 105 is shunted to the second antenna 109. This has the effect of reducing the local average SAR. The resonance of the second antenna 109 and the first matching circuit 106 has the same frequency regardless of whether the upper housing 101 and the lower housing 102 are opened or closed, and the resonance frequencies are the transmission frequency and the reception frequency.
JP 2002-353719 A JP 2002-335180 A

  However, with respect to the method of reducing the local average SAR described in Patent Document 1, it is necessary to add a conductive metal element inside the casing, and the local average SAR is reduced by electromagnetic coupling with metal parts inside the casing. There was a problem that the effect was weak. In addition, the method of diverting the current at the feeding point described in Patent Document 1 is difficult to incorporate because the rod antenna needs to protrude to the outside of the housing, and the radiation characteristics are optimal for the call state. There is a problem that a high antenna gain cannot be obtained.

  Further, in a folding mobile phone, a ground wire is arranged in the vicinity of the hinge portion, and when the casing is opened, a conductive metal element having one end opened near the hinge portion is connected to the ground. However, there is a problem that the resonance of the conductive metal element is not optimal for the transmission frequency, and the effect of reducing the local average SAR is small.

  The present invention has been made to solve the conventional problems, and particularly to provide a portable wireless device capable of reducing local average SAR and improving antenna performance in a built-in antenna of a folding portable wireless device. Objective.

  In order to achieve the above object, a portable radio apparatus according to the present invention includes a first housing, a second housing, and a hinge portion that rotatably connects the first housing and the second housing. And an antenna element provided in the vicinity of the hinge portion of the second casing, and a conductor element provided in the first casing. The conductor element and the antenna element include the first casing and the second casing. Arranged to be close to each other at a predetermined interval when the housing is open, and larger than the predetermined interval when the first housing and the second housing are closed have. With this configuration, the antenna current can be dispersed in the antenna with a built-in housing, the local average SAR can be reduced, and a high antenna gain can be obtained.

  The portable wireless device according to the present invention includes a first housing, a second housing, a hinge portion that rotatably connects the first housing and the second housing, and the first housing. A first antenna element provided on the body, a circuit board having a ground pattern provided inside the second housing, and a first hinge part and a second hinge part made of conductive metal provided on the hinge part. A connecting portion that electrically connects the first hinge portion and the second hinge portion and rotatably supports the first hinge portion, a first power feeding portion provided in the second hinge portion, and the second housing The second antenna element provided in the vicinity of the hinge part, the second feeding part provided at the end of the second antenna element, and either the first antenna element or the second antenna element are selected. An antenna switching circuit connected to a radio circuit, wherein the first hinge portion is the first housing. The second hinge portion is provided in the second housing and has a predetermined distance from the ground pattern on the circuit board. The conductor element and the second antenna element are arranged at a predetermined interval when the first casing and the second casing are opened, and the first casing and the second antenna element are spaced apart from each other. When the second casing is in a closed state, the second casing is arranged so as to have an interval larger than the predetermined interval. With this configuration, the antenna current can be dispersed in the antenna with a built-in housing, the local average SAR can be reduced, and a high antenna gain can be obtained.

  Further, in the portable wireless device according to the present invention, when the first casing and the second casing are in an open state, the second antenna element resonates in a transmission frequency band when the conductor element is in an open state. When the first casing and the second casing are closed, the second antenna element is arranged to resonate in the transmission frequency band and the reception frequency band. With this configuration, the antenna current can be dispersed in the antenna with a built-in housing, the local average SAR can be reduced, and a high antenna gain can be obtained.

  ADVANTAGE OF THE INVENTION According to this invention, in a housing built-in antenna, an antenna electric current can be disperse | distributed, the local average SAR can be reduced, and the portable radio | wireless apparatus from which a high antenna gain is obtained can be provided.

Embodiments of a portable radio apparatus according to the present invention will be described below in detail with reference to the accompanying drawings.
FIG. 1 is a configuration diagram showing a state in which a casing of a portable radio apparatus according to an embodiment of the present invention is opened, and FIG. 2 is a configuration showing a state in which the casing of the portable radio apparatus according to the first embodiment of the present invention is closed. FIGS. 3 and 3 are perspective views showing a call state in which the user holds the portable wireless device with the hand H. FIG.

  The portable wireless device of this embodiment is openable and closable in which a first casing (hereinafter referred to as an upper casing 1) and a second casing (hereinafter referred to as a lower casing 2) are connected by a hinge portion 3. It has such a structure that it can take two states, an open state and a closed state, by rotating around the hinge portion 3. Further, as will be described later, the portable wireless device of the present embodiment includes a first antenna 4, a second antenna 5, and a case opening / closing detection unit 6 that detects the open / closed state of the upper housing 1 and the lower housing 2. It has. In the present embodiment, the first frequency band corresponds to the transmission frequency, and the second frequency band corresponds to the reception frequency.

First, the configuration of the first antenna 4 will be described.
As shown in FIG. 1, the upper housing 1 has a metal frame 1A attached to the surface on the + X side in FIG. 1B, that is, the inner side surface on which the display unit is generally arranged. In B), a conductor element 7 to be described later is installed on the outer surface which is the surface on the -X side. In the present embodiment, the metal frame 1A, a hinge part 3 and a circuit board 21, which will be described later, constitute a first antenna 4 as a kind of dipole antenna.
As the metal frame 1A, a metal having high conductivity, light weight and high strength, for example, a magnesium alloy is used. As a result, the strength of the thin upper casing 1 is secured and the metal frame 1A also operates as the first antenna element. Generally, the long side length (L1) of the metal frame 1A is about 90 mm. The metal frame 1A and a hinge fitting 11 to be described later are electrically connected and mechanically fixed by being attached to the upper housing 1 with an attachment screw 11A.

  On the other hand, the hinge part 3 is provided with a hinge metal fitting 11 constituting a first hinge part and a columnar conductor 41 having a columnar shape and constituting a connecting part. The hinge fitting 11 and the cylindrical conductor 41 are made of a conductive material and are mechanically and electrically connected to each other. Further, the columnar conductor 41 and the rotating shaft 41A protruding from one end surface of the columnar conductor 41 are mechanically and electrically connected. The rotating shaft 41A is supported by the first power supply fitting 42 that constitutes the second hinge portion so as to be rotatable, for example, by a bearing structure. At the same time, the rotation shaft 41A and the first power supply fitting 42 are electrically connected. Secured. The support shaft 41B protruding from one end surface of the cylindrical conductor 41 is formed of a molded product made of a resin material, and the left end of the cylindrical conductor 41 is rotatably supported by the lower housing 2 by the support shaft 41B. .

  By configuring the hinge portion 3 as described above, the upper housing 1 is rotatably supported, and the metal frame 1A to the first power supply fitting 42 are electrically connected. In addition, the metal frame 1A having a length (L1) of, for example, about 90 mm is supplied with power from a first matching circuit 22 to be described later via the hinge portion 3, and the first antenna 4 has a length (L2). The hinge portion 3 and the metal frame 1A of about 110 mm and the circuit board 21 having a length (L3) of about 90 mm operate as a kind of dipole antenna.

  The first power supply fitting 42 is connected to the first matching circuit 22 on the circuit board 21 disposed inside the lower housing 2 by, for example, spring contact or soldering. The first matching circuit 22 has a function of matching the impedance of the first antenna 4 with the input impedance (generally 50Ω) of the radio circuit 24 and is connected to the antenna switching circuit 23. The circuit board 21 is composed of a printed circuit board on which circuit components that realize various functions of the portable wireless device are mounted, and a ground pattern serving as a circuit ground potential is formed on almost the entire surface.

Next, the configuration of the second antenna 5 will be described.
The second antenna 5 of this embodiment includes a conductor element 7 together with the second antenna element 51. The second antenna element 51 is arranged at a position near the feeding point of the first antenna 4 of the lower housing 2, that is, near the end on the + Z direction side. In addition, the second antenna element 51 is on the side away from the user (human body), that is, on the −X direction side of the lower housing 2 in FIG. It is arranged near the outer surface which is a surface. The second antenna element 51 has one end connected to the second power supply fitting 52 by, for example, spring contact or soldering, and the other end opened. The second power supply fitting 52 is connected to a pattern connected to the second matching circuit 25 on the circuit board 21 disposed inside the lower housing 2 by, for example, spring contact or soldering.

The second matching circuit 25 functions to match the impedance of the second antenna 5 to the input impedance (generally 50Ω) of the radio circuit 24, and has one end connected to the second antenna 5 and a housing. With the closed, the resonance is adjusted to the transmission band and the reception band. The other end of the second matching circuit 25 is connected to the switching circuit 26. The switching circuit 26 selects one of the antenna switching circuit 23 and the grant pattern of the circuit board 21 and connects it to the second matching circuit 25. The switching circuit 26 is preferably composed of a pin diode, and performs switching control according to the detection result of the housing open / close detection means 6.
The antenna switching circuit 23 selects one of the first matching circuit 22 and the switching circuit 26 and connects to the radio circuit 24. The antenna switching circuit 23 is composed of, for example, a GaAs switch or the like. The switching control is performed based on the detection result of the casing open / close detection means 6 that detects the open / close state of the body 2.
The wireless circuit 24 has functions of both transmission and reception of the portable wireless device, is mounted on the circuit board 21, and its transmission / reception input / output is connected to the antenna switching circuit 23.

  The case open / close detection means 6 includes a hall element 61 arranged on the circuit board 21 and a permanent magnet 62 arranged by cutting out a part of the metal frame 1A. It arrange | positions in the state which the permanent magnet 62 opposes. That is, the case open / close detection means 6 utilizes the fact that the distance between the Hall element 61 and the permanent magnet 62 is different between when the case is opened and when the case is closed. By detecting the opening and closing of the housing. Further, data related to the detection result of the opening / closing of the housing is output to the antenna switching circuit 23 and the switching circuit 26.

  The conductor element 7 is made of a material having high conductivity, and is located near the hinge portion 3 of the upper housing 1, that is, near the −Z direction in FIG. In the state, the lower housing 2 is disposed at a position close to a later-described second antenna element 51, that is, on the outer surface which is the surface of the upper housing 1 on the −X side. In addition, the conductor element 43 is connected to the hinge fitting 11 or a member having the same potential as that by spring contact or soldering, and electrical continuity is ensured. With such a configuration, the distance between the conductor element 7 and the second antenna 5 is close when the casing is opened, and the distance becomes larger when the casing is closed. The arrangement and shape of the conductor element 7 and the matching circuit 25 are such that the resonance frequency of the second antenna becomes the transmission frequency band when the housing is opened, and the resonance frequency of the second antenna is the transmission frequency when the housing is closed. It is determined to be a band and a reception frequency band.

The operation of the foldable portable wireless device of the present embodiment configured as described above will be described.
(1) First, the case where it is detected by the case opening / closing detection means 6 that the case has been opened will be described with reference to FIG.
The first antenna 4 is connected to the radio circuit 24 via the first matching circuit 22 and the antenna switching circuit 23. On the other hand, the second antenna 5 is connected to the high-frequency ground of the circuit board 21 via the second matching circuit 25 and the switching circuit 26. The resonance frequency of the second antenna 5 is a transmission frequency band.
In general, the antenna current and the local average SAR are in a correspondence relationship, and it is known that the local average SAR increases when the maximum point of the antenna current is concentrated in one place and the maximum point exists in the vicinity of the human body. . Therefore, if the maximum points of the antenna current are dispersed and the maximum points of the antenna current are separated from the human body, the local average SAR can be reduced. Therefore, in the present invention, the distance between the conductor element 7 and the second antenna 5 is brought close to each other so that the mutual electromagnetic coupling amount is increased and the resonance frequency of the second antenna 5 is adjusted to the transmission frequency band. As a result, the antenna current excited to the second antenna 5 away from the human body increases, the antenna current excited to the first antenna 4 relatively close to the human body decreases, and the local average SAR can be reduced.

(2) Next, the case where it is detected by the case opening / closing detection means 6 that the case has been closed will be described with reference to FIG.
The antenna element 51 of the second antenna 5 is connected to the radio circuit 24 via the second matching circuit 25, the switching circuit 26, and the antenna switching circuit 23. When the casing is closed, the distance between the conductor element 7 and the antenna element 51 is increased to change the mutual electromagnetic coupling amount, so that the resonance frequency of the second antenna 5 is set to the transmission frequency band and the reception frequency. Adjust to obi. Thereby, high antenna performance can be secured in both the transmission frequency band and the reception frequency band.

  As described above, according to the portable wireless device of the present embodiment, the resonance frequency of the second antenna 5 is adjusted to the transmission frequency band when the housing is open, and the antenna current of the first antenna 4 is set to the second frequency. By diverting the current to the antenna 5, the local average SAR can be reduced and a high antenna gain can be obtained.

  The present invention is not limited to the embodiment described above, and can be implemented in various forms without departing from the gist of the present invention. That is, the first power supply fitting 42 and the metal frame 1A may be arranged so as to be capacitively coupled in the transmission frequency band and the reception frequency band. In this case, for example, a resin material is used regardless of the material of the hinge metal fitting 11 and the cylindrical conductor 41. It may be. The conductor element 7 may be any element that changes the resonance frequency of the second antenna 5 to the transmission frequency band when the housing is opened, regardless of the shape or the arrangement position. Further, the second matching circuit 25 divides the antenna current to the second antenna 5 by connecting the ground pattern of the circuit board 21 to the feeding point of the first antenna or the first matching circuit or by capacitive coupling. Also good. Note that the first matching circuit 22 and the second matching circuit 25 may be used by sharing a part of the circuit, and in the case of sharing, the resonance frequency may be controlled using a variable capacitance diode.

  The portable wireless device of the present invention can disperse the antenna current in the antenna built in the housing, reduce the local average SAR, and obtain a high antenna gain. It has the effect of reducing the average SAR, and is useful for foldable mobile phones and the like.

1A and 1B show a basic configuration when a casing of a portable wireless device according to an embodiment of the present invention is opened, (A) is a plan view, and (B) is a side view. The basic configuration when the casing of the portable wireless device is closed is shown, (A) is a plan view, and (B) is a side view. Explanatory drawing showing a state when a user makes a call while holding the portable wireless device by hand It shows a basic configuration when the casing of a conventional portable wireless device is opened, (A) is a plan view, (B) is a side view. It shows a basic configuration when the casing of a conventional portable wireless device is closed, (A) is a plan view, (B) is a side view.

Explanation of symbols

1 Upper housing 1A Metal frame (first antenna element)
11 Hinge bracket (first hinge part)
11A Mounting screw 2 Lower housing 21 Circuit board 22 First matching circuit 23 Antenna switching circuit 24 Radio circuit 25 Second matching circuit 26 Switching circuit 3 Hinge part 4 First antenna 41 Cylindrical conductor (connecting part)
41A Rotating shaft 41B Support shaft 42 First power supply fitting (second hinge portion: first power supply portion)
5 2nd antenna 51 2nd antenna element 52 2nd feeding metal fitting (2nd feeding part)
6 Housing Open / Close Detection Unit 61 Hall Element 62 Permanent Magnet 7 Conductor Element

Claims (3)

A first housing;
A second housing;
A hinge portion that rotatably connects the first housing and the second housing;
An antenna element provided in the vicinity of the hinge portion of the second housing;
A conductor element provided in the first housing;
The conductor element and the antenna element are:
When the first housing and the second housing are in an open state, they are close to each other at a predetermined interval,
A portable wireless device arranged so that the interval is larger than the predetermined interval when the first casing and the second casing are closed. A first housing;
A second housing;
A hinge portion that rotatably connects the first housing and the second housing;
A first antenna element provided in the first housing;
A circuit board having a ground pattern provided in the second housing;
A first hinge part and a second hinge part made of conductive metal provided on the hinge part;
A connecting part that electrically connects the first hinge part and the second hinge part and rotatably supports the first hinge part;
A first power feeding portion provided in the second hinge portion;
A second antenna element provided in the vicinity of the hinge portion of the second housing;
A second feeder provided at an end of the second antenna element;
An antenna switching circuit that selects one of the first antenna element and the second antenna element and connects to the radio circuit;
The first hinge part is provided in the first housing and is electrically connected to an end of the first antenna element on the hinge part side;
The second hinge portion is provided in the second casing, and is arranged with a predetermined interval from a ground pattern on the circuit board,
The conductor element and the second antenna element are:
When the first housing and the second housing are in an open state, they are close to each other at a predetermined interval,
A portable wireless device arranged so that the interval is larger than the predetermined interval when the first casing and the second casing are closed. The conductor element is
When the first housing and the second housing are in an open state, the second antenna element resonates in the transmission frequency band,
The portable radio apparatus according to claim 1 or 2, wherein the second antenna element is arranged to resonate in a transmission frequency band and a reception frequency band when the first casing and the second casing are closed.

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