WO2004049583A1

WO2004049583A1 - Radio communication apparatus

Info

Publication number: WO2004049583A1
Application number: PCT/JP2003/014628
Authority: WO
Inventors: Tomoaki Nishikido; Yutaka Saito; Hiroshi Haruki; Kiyoshi Egawa
Original assignee: Matsushita Electric Industrial Co., Ltd.
Priority date: 2002-11-27
Filing date: 2003-11-18
Publication date: 2004-06-10
Also published as: AU2003280839A1; JP2004179995A

Abstract

Antennas (5,11) are provided in end portions of upper and lower housings (3,4), respectively, and high frequency switches (14,15) are also provided on two high frequency coaxial cables (19,20), respectively, for supplying and distributing powers. It is arranged that one of the high frequency switches (14,15) be turned off in association with a result of detecting a hand of the user approaching the antennas. In this way, a high antenna radiation efficiency can be ensured without affecting communication even in a case of a radio communication apparatus of CDMA system that performs a continuous transmission operation and a transmission power control or a radio communication apparatus of folding type, and further even when any portion of the present apparatus (1) is held by the user's hand.

Description

Wireless communication device

Technical field

The present invention relates to a wireless communication device such as a mobile phone. Light

Background art

Conventionally, wireless communication devices such as mobile phones that adopt the time division multiple access (TDMA) method such as the PDC (Personal Digital Cellular) method and the PHS (Personal Handy-Phone System) method Some systems perform a diversity operation that selectively switches between two antennas according to the state to improve communication quality in a multipath fading environment.

Also, for example, when using a mobile phone, that is, when making a call or performing an e-mail operation, the user naturally has the device body, but at that time, the user is conscious of the arrangement of the antenna. It is rare to do so, and there is a possibility that the location of the antenna is grasped by hand. If the area where the antenna is placed is covered by hand, the radiation efficiency of the antenna is generally greatly reduced to 110 to 15 dB, and the communication quality is significantly deteriorated.

Assuming that antennas are placed at each of a plurality of parts relatively distant from the part that the user normally holds, even if one antenna is covered by the user's hand and the performance deteriorates, the remaining antennas The communication quality can be ensured by switching the antenna so that the performance of the antenna can be ensured. In this case, at the moment when the antenna is switched during communication, the antenna is temporarily disconnected, that is, the antenna is opened. In addition, the antenna gain fluctuates significantly before and after switching.In particular, in the TDMA method, antenna switching diversity operation is performed during guard times other than the time slots required for communication, so the antenna instantaneous Open or gain fluctuation does not matter.

On the other hand, in a code division multiple access (CDMA) system, which has recently started service, since the continuous transmission operation and transmission power control are generally performed on the wireless communication device side, the above antenna switching diver is used. It is difficult to carry out the Sichi operation.

Therefore, a code division multiple access system is disclosed in Japanese Patent Application Laid-Open No. 2001-292017 (page 3, FIG. 2) in which the directivity control antenna is arranged near the microphone. In this configuration, an antenna element and an antenna reflector are arranged near the microphone, and the directivity is continuously changed by controlling the impedance of the antenna reflector according to the reception intensity.

A configuration using a four-part feed antenna is disclosed in JP-A-2002-77006 (page 2, FIG. 1). In this configuration, four small antennas are provided on a mobile phone, and each small antenna is distributed and fed constantly. Further, a configuration in which two dipole antennas are provided and the supply potential phase of each dipole antenna is controlled is disclosed in Japanese Patent Application Laid-Open No. 2002-521515 (page 2, page 3, FIG. 2). .

However, the conventional wireless communication device has the following problems.

(1) In the configuration in which the directivity control antenna is placed near the microphone, the vicinity of the microphone is likely to be covered by the user's hand during a call or e-mail operation, and the antenna performance is likely to deteriorate in actual use.

(2) In the configuration using the four-distribution power feeding antenna, the effect of improving the SAR (Specific Absorption Rate) by the distributed power feeding is shown, but it is covered with hands in the foldable mobile phone, which has been spreading in recent years. However, it is not considered that the antenna should be properly positioned to prevent antenna performance degradation.

(3) In the configuration using two dipole antennas, the directivity changes due to phase control are shown. Not considered. Disclosure of the invention

It is an object of the present invention to minimize the antenna performance degradation when a user holds the device body, and to achieve high antenna radiation efficiency, even in a wireless communication device of the CDMA system and a foldable wireless communication device. An object of the present invention is to provide a wireless communication device that can be secured.

The present invention provides an antenna for each of the-and other parts of a housing composed of two parts that can be folded around a hinge, and distributes and feeds them at the same time. The object is achieved by ensuring high antenna radiation efficiency regardless of what part of the device body is held by hand. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a basic configuration diagram showing a wireless communication device according to Embodiment 1 of the present invention, FIG. 2 is a cross-sectional view of the wireless communication device of FIG.

FIG. 3 is a diagram showing a call use state of the wireless communication device according to the first embodiment of the present invention, FIG. 4 is a diagram showing an email operation state of the wireless communication device according to the first embodiment of the present invention,

FIG.5A is a diagram showing a position of a hand of a user holding the wireless communication device according to Embodiment 1 of the present invention,

FIG.5B is a diagram showing the position of the hand of the user holding the wireless communication device according to Embodiment 1 of the present invention,

FIG.5C is a diagram showing the position of the hand of the user holding the wireless communication device according to Embodiment 1 of the present invention,

FIG. 6 is a basic configuration diagram showing a wireless communication device according to Embodiment 2 of the present invention, FIG. 7 is a basic configuration diagram showing a wireless communication device according to Embodiment 3 of the present invention, and FIG. FIG. 14 is a basic configuration diagram showing a wireless communication device according to Embodiment 4 of the present invention. BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Embodiment 1)

FIG. 1 is a front view of a wireless communication device according to Embodiment 1 of the present invention as viewed from the front. FIG. 2 is a cross-sectional view of the wireless communication device of FIG. 1 taken along line AA ′.

As shown in FIG. 1, a wireless communication device 1 according to the present embodiment includes two portions that can be folded around hinge 2, that is, an upper housing 3 and a lower housing 4. Both the upper casing 3 and the lower casing 4 are made of a resin such as plastic.

Hereinafter, the wireless communication device 1 according to the present embodiment will be described with reference to FIG. 1 and FIG. The operating frequency of the device 1 is set in the 2 GHz band. The upper housing 3 includes an antenna 5, a matching circuit 6 for matching the impedance of the antenna 5 to 50 Ω, and a detector 7 for detecting the approach of the body (mainly a hand) of the user of the device. Is provided.

The antenna 5 is arranged at the tip of the upper housing 3 with its length direction facing the width of the upper housing 3. As the antenna 5, for example, a λZ4 monopole antenna formed by an L-shaped copper wire having an electric length of a quarter wavelength (about 37.5 mm) is used. The matching circuit 6 is disposed on the circuit board 8 of the upper housing 3 內. The detector 7 is arranged on a surface of the upper housing 3 facing the surface on which the liquid crystal display 9 is provided, and at a position separated from the antenna 5 by about 5 mm, as shown in FIG. The detector 7 is an object proximity sensor using static electricity, detects the approach of the body (mainly a hand) of the user of the present device, and notifies the control unit 10 (see FIG. 1) described later. On the other hand, the lower housing 4 includes an antenna 11, a matching circuit 12 for matching the impedance of the antenna 11 to 50 Ω, and a detector 13 for detecting the approach of the user's hand. , High frequency switches 14 and 15, a power distribution combiner 16, and a transmission / reception circuit 17.

The antenna 11 is located at the tip of the lower housing 4 and the length direction is the width of the lower housing 4. It is arranged facing the direction. As the antenna 11, a / 4 monopole antenna is used in the same manner as the antenna 5 described above.

The matching circuit 12, the high-frequency switches 14 and 15, the power distribution combiner 16, and the transmission / reception circuit 17 are arranged on a circuit board 18 in the lower housing 4.

The high-frequency switch 14 and the matching circuit 6 of the upper housing 3 are connected by a high-frequency coaxial cable 19 as a feed line. Further, the high-frequency switch 15 and the matching circuit 12 are connected by a high-frequency coaxial cape 20 as a feed line.

The power distribution combiner 16 is connected to each of the high-frequency switches 14 and 15 and to the transmission / reception circuit 17. The power splitter / synthesizer 16 is an in-phase splitter such as a Wilkinson Divider, for example.

As shown in FIG. 2, the detector 13 is disposed on a surface of the lower housing 4 facing the arrangement surface of the key operation unit 21 and at a position separated from the antenna 11 by about 5 mm. Returning to FIG. 1, the detector 13 is an object proximity sensor using static electricity or the like, similar to the detector 7 described above, and detects the proximity of the hand of the user of this device and notifies the control unit 10. You.

Next, an operation of the wireless communication apparatus 1 according to the present embodiment will be described with reference to use state diagrams shown in FIGS.

FIG. 3 shows a state in which the user 100 holds a telephone call while holding the device 1 (hereinafter, a call state), and FIG. 4 shows a state in which an e-mail operation is performed (hereinafter, a call state). Operating state).

FIG. 5 is a diagram schematically showing a difference in hand position when the user 100 holds the main unit 1 by hand in the above-mentioned call state or e-mail operation state. That is, FIG. 5A shows a case where the lower housing 4 of the device 1 is held at a lower position (lower holding state), and FIG. 5B shows a case where the vicinity of the hinge portion 2 in the center of the device 1 is held. FIG. 5C shows a case where the upper housing 3 of the device 1 is held (upper holding state).

First, as shown in Fig. 5B, the antenna 5 and The hand of the user 100 is not near the antenna and the antenna 11. In such a state, a signal indicating that there is nothing close to the detection unit 7 and the detection unit 13 is sent to the control unit 10. The control section 10 receives this signal and sets the high frequency switches 14 and 15 to ON. When the high frequency switches 14 and 15 are both on and the device 1 is in the receiving state, the received signals received by the antenna 5 and the antenna 11 are transmitted by the power distribution combiner 16. The signals are combined with the same amplitude ratio, and the combined signal is taken into the transmission / reception circuit 17.

On the other hand, when the device 1 is in the transmission state, the transmission signal output from the transmission / reception circuit 17 is distributed with the same amplitude by the power distribution combiner 16 and supplied to the antenna 5 and the antenna 11 . At this time, the difference between the signal phase of antenna 5 and the signal phase of antenna 11 is determined by the difference in electrical length between high-frequency coaxial cable 19 and high-frequency coaxial cable 20. In the central holding state and the talking state, the antenna radiation efficiency in the state where the power is distributed and supplied to both the antenna 5 and the antenna 11 as described above is about 15 dB, and it is possible to secure good communication performance. it can.

Next, as shown in FIG. 5A, in a state where the lower part of the apparatus main body is held, the antenna 11 is covered by hand, but the antenna 5 is not covered. At this time, the antenna performance of the antenna 11 is significantly degraded due to the electromagnetic interaction with the hand in proximity. Here, assuming that the antenna 5 and the power distribution combiner 16 are absent and power is supplied only to the antenna 11, the antenna radiation efficiency in a call state is degraded to 114 dB.

Next, the operation of the device 1 when switching by the high frequency switch 14 and the high frequency switch 15 will be described.

In the lower holding state, the detector 13 detects the approaching hand, sends a signal indicating the detection to the control unit 10, and sends a signal indicating that the detector 7 does not approach the control unit 10. Send to In response to this signal, the control unit 10 sets the high-frequency switch 14 to ON, and sets the high-frequency switch 15 to OFF. In this case, the antenna radiation efficiency of the lower holding state and the talking state is 16 dB, and the above antenna 1 1 1 8 dB better than when only power is supplied to

The reason why the antenna efficiency is improved is that the antenna 11 whose performance has been significantly degraded is separated from the power supply system. Note that the loss at this time is only the increase in the input loss on the antenna 5 side due to the open side of the power distribution mixer 16 (antenna 11 side). Therefore, in the lower holding state, the antenna 11 is disconnected from the feed system, and only the antenna 5 is used.

Next, consider a state in which the upper part shown in FIG. In this case, the detector 7 detects the proximity of the hand, and the detector 13 sends a signal indicating that there is no proximity of the hand to the control unit 10. In response to this signal, the control unit 10 turns off the high-frequency switch 14 and turns on the high-frequency switch 15. In this case, the antenna radiation efficiency of the upper holding state and the talking state is 16 dB, and a good antenna radiation efficiency is obtained.

Next, in the e-mail operation state shown in FIG. 4, since the lower part is often held in the state shown in FIG. 5A, the high frequency switch 14 is set to ON and the high frequency switch 15 is set in this state. Is set to off. In this case, a high antenna radiation efficiency of 15 dB can be obtained.

In the wireless communication device 1 having such a configuration, when the position of the user's hand changes to the lower part, the center part, or the upper part in various use states, the change in the antenna radiation efficiency is within about 2 dB, and The fluctuation range is relatively small. Also, even at the moment when the high-frequency switches 14 and 15 are switched, one of the antennas is always connected, so that the antenna does not open. Therefore, even if the device 1 adopts a code division multiple access (CDMA) system for performing a continuous transmission operation and transmission power control, it does not hinder communication.

As described above, according to the wireless communication device 1 according to the present embodiment, the antennas 5 and 11 are disposed at the distal end of the upper housing 3 and the distal end of the lower housing 4, respectively, so that two power sources for distributed power supply are provided. High-frequency switches 14 and 15 are provided on the feed lines 19 and 20, respectively. The CDMA that performs continuous transmission operation and transmission power control by turning off one of the high-frequency switches 14 and 15 in conjunction with the result of detecting that the user's hand is approaching the antenna A high antenna radiation efficiency can be ensured regardless of what part of the device 1 is held by the user's hand without disturbing the communication of the system.

The effect of improving the antenna radiation efficiency is almost constant irrespective of the relative difference between the signal phases of the two antennas. Even if there is an error in the relative accuracy of the electrical length of the feed line, the effect can be obtained.

In the present embodiment, two antennas 5 and 11 and two detectors 7 and 13 are used. However, the number is not limited to two, and for example, three or more. If the third antenna and the detector are arranged in the hinge part, a higher improvement effect can be obtained.

Further, in the present embodiment, a / 4 monopole antenna is used for the antennas 5 and 11, but is not limited to this type of antenna. For example, a one-wavelength dipole antenna, a half-wavelength pole antenna, an inverted F antenna, a helical antenna , Inverted L antenna, meander line antenna, patch antenna, whip antenna, λ / 2 monopole antenna, etc. can be used. For example, by using a one-wavelength dipole antenna or a half-wavelength pole antenna as the antenna built in the upper housing 3, the effective gain in the horizontal (Χ Υ) plane direction in the lower holding state or the center holding state during a call can be increased. can do.

Further, in the present embodiment, a Wilkinson type divider is used as power divider / synthesizer 16, but the present invention is not limited to this, and any power divider having bidirectionality can be used. It does not matter.

Further, in the present embodiment, high-frequency coaxial cables 19 and 20 are used as power supply lines used in the power supply system. However, the present invention is not limited to high-frequency coaxial cables, and is formed on a circuit board such as a microstrip line. A transmission line may be used. Further, in the present embodiment, the detectors 7 and 13 for detecting the proximity of the hand are of an electrostatic type, but for example, a photosensor or a camera is used to detect the luminous intensity when covered with the hand. May be detected.

(Embodiment 2)

FIG. 6 is a basic configuration diagram of a wireless communication device according to Embodiment 2 of the present invention. The wireless communication device 30 according to the present embodiment is obtained by removing the high-frequency switches 14 and 15, the detectors 7 and 13, and the control unit 10 in the wireless communication device 1 shown in FIG. 1 described above. The components denoted by the same reference numerals as those in FIG. 1 indicate the same components.

In FIG. 6, radio communication apparatus 30 according to the present embodiment employs a configuration in which antenna 5 and antenna 11 are always distributed and fed by power distribution combiner 16. Therefore, this configuration is equivalent to a state in which high-frequency switch 14 and high-frequency switch 15 are always on in wireless communication device 1 shown in FIG.

In such a configuration, the antenna radiation efficiency is about 15 dB in a state where the center is held as shown in FIG. 5B and in a call state. In addition, as shown in Fig. 5A, in the lower holding state, even though the performance of the antenna 11 is significantly degraded, the performance of the antenna 5 to which power is distributed and fed at the same time is sufficiently high. Antenna radiation efficiency is obtained. By distributing and supplying power to both the antenna 5 and the antenna 11, a certain effect of improving the antenna radiation efficiency can be obtained without performing the switching operation by the high frequency switch 14 and the high frequency switch 15. As described above, the wireless communication device 30 according to the present embodiment is arranged such that antennas are arranged at the distal end portion of the upper housing 3 and the distal end portion of the lower housing 4, respectively, so that they are simultaneously distributed and fed. Therefore, high antenna radiation efficiency can be ensured regardless of what part of the device 30 is held by the user's hand.

(Embodiment 3)

FIG. 7 is a basic configuration diagram of wireless communication apparatus 40 according to Embodiment 3 of the present invention. The wireless communication device 40 according to the present embodiment is the same as the wireless communication device shown in FIG. The detectors 7 and 13 of the device 1 are replaced with minute antennas 41 and 43 and detection circuits 42 and 44, respectively. In this drawing, components denoted by the same reference numerals as those in FIG. 1 indicate the same components, and a detailed description thereof will be omitted.

In FIG. 7, the minute antenna 41 is disposed near the antenna 5 (for example, at a distance of 5 mm), and the minute antenna 43 is disposed near the antenna 11 (for example, at a distance of 5 mm). The minute antennas 41 and 43 are constituted by minute loop antennas having a loop length of, for example, about 1/10 wavelength (15 mm).

The small antenna 41 is connected to the detection circuit 42. The detection circuit 42 includes a high-frequency signal amplification circuit and a level detection circuit (not shown). The small antenna 43 is connected to the detection circuit 44. The detection circuit 44 includes a high-frequency signal width circuit and a level detection circuit. A part of the transmission signal transmitted from the antenna 5 is detected by the minute antenna 41, the detected high-frequency signal is detected by the detection circuit 42, and the result is input to the control unit 10. In addition, a part of the transmission signal transmitted from the antenna 11 is detected by the minute antenna 43, the detected high-frequency signal is detected by the detection circuit 44, and the result is input to the control unit 10 .

Here, as shown in FIG. 5A, in the lower holding state, the antenna 11 and the small antenna 43 are covered with hands, and the performance of both antennas is significantly deteriorated. In this case, the detection output level of the detection circuit 44 becomes low. In addition, as shown in FIG. 5C, in the upper holding state, the antenna 5 and the small antenna 41 are covered by hands, so that the performance of both antennas is significantly deteriorated, and the detection output level of the detection circuit 42 becomes lower. Lower.

By notifying the control unit 10 of the change in the detection level as described above, the control unit 10 is configured to perform the switching control of the high-frequency switch 14 and the high-frequency switch 15, so that the user can manually control the switch. High antenna radiation efficiency can be ensured no matter what part of the device 40 is held.

As described above, the radio communication device 40 according to the present embodiment has the small antenna 41 and the detection circuit 42 arranged near the antenna 5 arranged at the tip of the upper housing 3. A small antenna 43 and a detection circuit 44 are placed near the antenna 11 placed at the tip of the lower housing 4 to detect the approach of the hand to each of the upper housing 3 and the lower housing 4 The antenna 5 'and the antenna 11 are switched, so that a high antenna radiation efficiency can be secured regardless of what part of the device 40 is held by the user's hand. It becomes.

(Embodiment 4)

FIG. 8 is a basic configuration diagram of a wireless communication device according to Embodiment 4 of the present invention. Radio communication apparatus 50 according to the present embodiment is obtained by replacing antenna 5 of radio communication apparatus 30 shown in FIG. 6 with a one-wavelength dipole. In this figure, components denoted by the same reference numerals as those in FIG. 6 indicate the same components, and detailed description thereof will be omitted.

In FIG. 8, each of the dipole elements 51 and 52 is an L-shaped copper wire having an electric length of about a half wavelength (about 75 mm). The dipole elements 51 and 52 are connected to the balanced-unbalanced conversion element 53, and these constitute a one-wavelength dipole antenna. With such a configuration, the vertical polarization component can be increased in the radiation characteristics in the horizontal plane (XY plane) in the call state shown in FIG. As a result, the effective gain in the propagation environment of land mobile communication can be improved.

Thus, according to the wireless communication device 50 of the present embodiment, the state where the lower portion of the device main body is held as shown by A in FIG. 5 and the center of the device main body as shown in FIG. 5B are held In either the state or the state in which the upper part of the apparatus main body is held as shown in FIG. 5C, a high effective gain in a talking state can be secured. In the above embodiment, the dipole / ray elements 51 and 52 provided in the upper housing 3 are not limited to one-wavelength dipoles. For example, half-wavelength elements are arranged in the width direction of the device main body. With such a configuration, a similar effect can be obtained as long as the configuration can provide high vertical polarization component radiation in a call state.

As described above, according to the present invention, continuous transmission operation and transmission power control are performed. In both the CDMA wireless communication device and the foldable wireless communication device, deterioration of antenna performance when the user holds the device body can be minimized, and high antenna radiation efficiency can be secured.

The present specification is based on Japanese Patent Application No. 2002-344143 filed on Jan. 27, 2002. This content is included here. Industrial applicability

The present invention is suitable for use in a wireless communication device such as a mobile phone.

Claims

The scope of the claims

1. A first antenna provided in one part of a housing composed of two parts that can be folded around a hinge part,

A second antenna provided on the other part of the housing,

A power distribution combiner that distributes a transmission signal to the first antenna and the second antenna, and combines reception signals received by the first antenna and the second antenna;

A first feed line provided between the first antenna and the power distribution / synthesizer and having a predetermined electrical length;

A second feed line provided between the second antenna and the power distribution / synthesizer and having a predetermined electrical length;

A wireless communication device comprising:

2. A first antenna provided in one part of a housing composed of two parts that can be folded around a hinge part,

A second antenna provided on the other part of the housing,

A third antenna provided at a position separated from each of the first antenna and the second antenna;

Power distribution combining for distributing a transmission signal to the first antenna, the second antenna, and the third antenna, and for combining the reception signals received by the first antenna, the second antenna, and the third antenna; Container,

A third feed line provided between the third antenna and the power distribution / synthesizer and having a predetermined electrical length;

A wireless communication device comprising:

3. A first antenna provided in one part of a housing composed of two parts that can be folded around a hinge part,

A second antenna provided on the other part of the housing,

A second water supply path provided between the second antenna and the power distribution / combination unit and having a predetermined electrical length;

A first high-frequency switch which is provided on a part of the first feeder line and is normally closed,

A second high-frequency switch, which is provided on a part of the second power supply line and is normally closed,

A first detector for detecting contact of a human body with one part of the housing,

A second detector for detecting contact of the human body with the other part of the housing,

The first high frequency switch is opened when the first detector detects a human body contact, and the second high frequency switch is opened when the second detector detects a human body contact. A control circuit for setting a state;

A wireless communication device comprising:

4. The wireless communication device according to claim 3, wherein the first detector and the second detector include any one of a touch sensor using a change in capacitance, a photo sensor that detects luminous intensity, and a camera. .

5. The first detector and the second detector detect an antenna and a modulated wave signal transmitted from the first antenna or the second antenna captured by the antenna and output a detected signal. And a detector, wherein the first detector is arranged near the first antenna, and the second detector is 5. The wireless communication device according to claim 4, wherein the wireless communication device is arranged near the tenor.

6. The wireless communication device according to claim 1, wherein the first antenna or the second antenna is formed to have a length of a quarter wavelength.

7. The wireless communication device according to claim 3, wherein the third antenna is formed to have a length of a quarter wavelength.

8. The wireless communication device according to claim 1, wherein the first antenna or the second antenna is a one-wavelength dipole antenna or a half-wavelength dipole antenna.