JP2006180193A - Antenna device and mobile wireless communication apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an antenna device capable of reducing electromagnetic wave radiation to a head of a human body without losing transmission quality and causing a greater detriment to miniaturization of the antenna device and miniaturization of a mobile telephone terminal apparatus mounted with the antenna device and to provide a mobile wireless communication apparatus mounted with the antenna device. <P>SOLUTION: The mobile telephone terminal apparatus 100 includes: the antenna device 101 and a transmission/reception section 102. The antenna device 101 includes: first and second antennas 103, 104; a selection means 105 for selecting an antenna used for wireless transmission/reception from the first and second antennas 103, 104; a control means 106 for controlling an antenna selection operation of the selection means 105; and a voice speech identification means 107 for detecting whether or not the antenna device 101 is close to the head of the human body and transmitting an identification signal to the control means 106. The control means 106 transmits a control signal to the selection means 105 for the selection of an antenna the electric energy of which absorbed by the head of the human body is smaller than a prescribed reference electric energy. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an antenna device that can be mounted on a portable wireless communication device, and a portable wireless communication device such as a portable wireless telephone terminal device on which the antenna device is mounted and wirelessly transmits and receives signals using the antenna device. The present invention relates to a technique for reducing the electromagnetic wave emission level to a user's head when electromagnetic waves are emitted from an apparatus (that is, radio wave emission).

  In recent years, the development of portable wireless communication devices has been remarkable. Among them, portable wireless telephone terminal devices (for example, so-called portable telephones) have become more and more multifunctional. Such a packet communication function, a videophone function for transmitting and receiving voice and images at the same time, a data communication function used by connecting to a personal computer, and the like have come to be configured.

  However, as a usage form of the mobile radio telephone terminal device, a voice call or the like in which the mobile radio telephone terminal device is brought into close contact with the human head will be mainly used. Therefore, the antenna device built in the portable radio telephone terminal device needs to keep good electromagnetic waves (that is, radio waves) emitted from the antenna device toward the human head (in other words, absorbed by the human head). It is necessary to reduce the amount of electromagnetic wave power to a safe amount).

  In addition, information such as image data and audio data obtained by an imaging device such as a digital camera, a digital video camera, or the like is stored in a built-in memory such as a personal computer or wired using a portable wireless communication device provided in the imaging device. Similarly, when the imaging device is used close to the human head when wirelessly transmitting to an external memory or data server that is not used, it is necessary to keep the amount of electromagnetic waves absorbed by the human head low.

  There is SAR (Specific Absorption Rate) as an index indicating the amount of electromagnetic wave power absorbed by the human head. Recently, SAR has been legalized in various countries, and interest is increasing. However, there is a high demand for miniaturization of portable wireless communication devices and a request to incorporate all antennas in the portable wireless communication device. Therefore, the design difficulty for obtaining good SAR characteristics increases, and the development man-hours of the portable wireless communication device are increased. Has become enormous.

  As a conventional method for maintaining good SAR characteristics of an antenna device built in a portable wireless communication device, the transmission antenna gain of the antenna device is lowered, or the distance between the antenna of the antenna device and the human head is A method of reducing the amount of electromagnetic wave radiated to the human head by arranging the antenna of the antenna device at a large position is generally known.

  However, lowering the transmission antenna gain of the antenna device built in the portable wireless communication device also lowers the reception antenna gain of the antenna device, and lowers the reception power of the radio signal. In this case, there is a very high possibility that the transmission quality originally required for the portable radio communication apparatus) will deteriorate.

  Further, in the method of disposing the antenna of the antenna device at a position where the distance between the antenna of the antenna device and the human head becomes large, a major factor that hinders downsizing of the antenna device (in other words, a portable wireless communication device). Become.

  In addition, an upper limit (that is, a threshold value) of a wireless transmission power level that can provide good SAR characteristics in all usage modes of the portable wireless communication device is stored in a memory in the portable wireless communication device, and the current wireless transmission power level is stored. There is also known an antenna device that maintains the SAR characteristics by switching the antenna to be used (see, for example, Patent Document 1).

  In the antenna device disclosed in Patent Document 1, since antenna switching is performed every time the actual wireless transmission power level crosses the threshold, baseband processing such as transmission power control is hindered. As a result, the antenna device ( In other words, there is a high possibility that the transmission quality originally required for the portable radio communication apparatus) will be deteriorated.

JP 2003-283393 A

  The present invention has been made in view of the above-described conventional circumstances, and does not greatly hinder downsizing of an antenna device and downsizing of a portable wireless communication device equipped with the antenna device, and can improve transmission quality. An object of the present invention is to provide an antenna device that can reduce electromagnetic radiation to the human head without damaging the device and a portable wireless communication device equipped with the antenna device.

The antenna device of the present invention is
An antenna device that can be mounted on a portable wireless communication device,
An antenna group consisting of a plurality of antennas;
Selecting means for selecting an antenna to be used for wireless transmission / reception from the antenna group;
Control means for controlling the antenna selection operation of the selection means;
Identifying means for identifying whether the antenna device is close to a human head;
With
The control means sends a control signal to the selection means so that the selection means selects the antenna to be used based on the identification result by the identification means.
According to this configuration, the antenna device (or the portable wireless communication device on which the antenna device is mounted) is close to the human head and the antenna device (or the portable wireless communication device on which the antenna device is mounted). The use form of the antenna device (or the portable wireless communication device on which the antenna device is mounted) at that time is determined based on the identification result by the identification means that the proximity means is not close to the human head. The most effective antenna can be selected. Therefore, for example, if an antenna group is composed of an antenna that can obtain a good SAR characteristic even at the maximum transmission power and an antenna that does not have a good SAR characteristic but has a high transmission antenna gain, the antenna device (or the antenna device is mounted). When the portable radio communication device is close to the human head, the antenna is switched to an antenna that can obtain good SAR characteristics even at the maximum transmission power, and the antenna device (or the portable radio communication device equipped with the antenna device) Is not close to the human head, the SAR characteristics are not good, but it is only necessary to switch to an antenna having a high transmission antenna gain, and the antenna device is located at a position where the distance between the antenna of the antenna device and the human head becomes large. Because there is no need to arrange the antenna, the antenna device is downsized and the antenna device is installed. Portable radio without a big obstacle to the miniaturization of the communication device, and without impairing the transmission quality, it can reduce the electromagnetic radiation into the human head.

Further, the antenna device of the present invention includes at least one antenna whose antenna group has a power amount of electromagnetic waves absorbed by the human head smaller than a predetermined reference power amount,
When the control unit is identified by the identification unit that the antenna device is close to the human head, the amount of electromagnetic wave absorbed by the human head is smaller than a predetermined reference power amount It is preferable to send a control signal to the selection means so as to select an antenna.
According to this configuration, when the antenna device (or the portable wireless communication device on which the antenna device is mounted) is not close to the human head, the best transmission quality can be obtained by selecting the optimum antenna from all the antennas. In addition, when the antenna device (or the portable wireless communication device on which the antenna device is mounted) is close to the human head, the amount of electromagnetic wave power absorbed by the human head is not affected by the wireless transmission power level. Since an antenna smaller than the predetermined reference power is selected, there is no need to lower the transmission antenna gain, and there is little influence on baseband processing due to frequent antenna switching, so that it is absorbed by the human head without impairing transmission quality. It is possible to satisfy the reference electric energy of the electromagnetic wave to be generated.

The antenna device of the present invention is
Measuring means for measuring the received power level of the signal by the antenna selected by the selecting means;
Storage means for storing a measurement result of the received power level by the measurement means;
Further comprising
The control means is configured such that, when the identification means identifies that the antenna device is close to the human head, the power of electromagnetic waves absorbed by the human head is smaller than a predetermined reference power It is preferable to send a control signal to the selection means so as to select the antenna having the highest received power level among the antennas among the measurement results stored in the storage means.
According to this configuration, when the antenna device (or the portable wireless communication device in which the antenna device is mounted) is not close to the human head, the antenna having the highest received power level is selected from all the antennas, and the antenna When the device (or the portable wireless communication device on which the antenna device is mounted) is close to the human head, the most received of the antennas whose electromagnetic energy absorbed by the human head is smaller than a predetermined reference power An antenna with a high power level can be selected, and the reference power amount of electromagnetic waves absorbed by the human head can be satisfied without impairing transmission quality.

The portable wireless communication device of the present invention is
The antenna device of the present invention described above;
A transmission / reception unit that is electrically connected to the antenna to be used and performs wireless transmission / reception of signals via the antenna;
Is provided.
According to this configuration, when the antenna device of the portable wireless communication device is not close to the human head, good transmission quality can be maintained by selecting an optimum antenna from all the antennas, and the portable wireless communication device When the antenna device is close to the human head, an antenna whose electromagnetic energy absorbed by the human head is smaller than a predetermined reference electric energy is selected regardless of the wireless transmission power level. There is no need for lowering and there is little influence on baseband processing due to frequent antenna switching, so that the reference power amount of electromagnetic waves absorbed by the human head can be satisfied without impairing transmission quality.

In the antenna device of the present invention,
The identification means is configured such that the transmitting / receiving unit of the portable wireless communication device that is electrically connected to the antenna to be used and wirelessly transmits / receives a signal through the antenna is in a voice call state, and the antenna device Detecting the proximity of the head and sending an identification signal to the control means, and the control means determines that the electric energy of the electromagnetic wave absorbed by the human head according to the identification signal is a predetermined reference electric energy It is preferable to send a control signal to the selection means so as to select a smaller antenna.
According to this configuration, it is possible to effectively reduce electromagnetic radiation to the human head at the time of a voice call in which the antenna device (or the portable wireless communication device on which the antenna device is mounted) is close to or in close contact with the human head. .

Similarly, in the portable wireless communication device of the present invention,
The identification means detects that the transmission / reception unit is in a voice call state as the portable wireless communication device is close to the human head, and sends an identification signal to the control means, and the control Preferably, the means sends a control signal to the selection means so as to select an antenna in which the amount of electromagnetic wave absorbed by the human head according to the identification signal is smaller than a predetermined reference power amount.
According to this configuration, it is possible to effectively reduce electromagnetic radiation to the human head at the time of a voice call in which the antenna device (or the portable wireless communication device on which the antenna device is mounted) is close to or in close contact with the human head. .

  Moreover, it is preferable that the portable radio communication apparatus of the present invention is a portable radio telephone terminal apparatus that has become very popular in recent years. Also in this case, as described above, a portable radio telephone terminal device that can reduce electromagnetic radiation to the human head without greatly hindering the miniaturization of the portable radio telephone terminal device and without impairing the transmission quality is provided. It goes without saying that you can do it.

  According to the present invention, it is possible to reduce the size of an antenna device and to reduce the size of a portable wireless communication device equipped with the antenna device, and to prevent electromagnetic radiation from being emitted to the human head without impairing transmission quality. It is possible to provide an antenna device that can be reduced and a portable wireless communication device equipped with the antenna device.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described in detail with reference to the drawings. Here, the present invention is an example of a portable wireless communication device equipped with an antenna device, and the present invention is applied to a portable wireless telephone terminal device (for example, a so-called mobile phone) that has become very popular in recent years. An antenna device and an embodiment of a portable wireless communication device equipped with the antenna device will be described.

  FIG. 1 is a block diagram showing a system configuration of a first embodiment of a portable radio communication apparatus (ie, portable radio telephone terminal apparatus 100) according to the present invention, and FIG. 2 shows a second embodiment of the portable radio communication apparatus according to the present invention. FIG. 3 is a block diagram showing the system configuration of the mobile radio telephone terminal apparatus 200, and FIG. 3 is a front view of the mobile radio telephone terminal apparatus according to the present invention.

[First Embodiment]
As shown in FIG. 1, the mobile radio telephone terminal device 100 includes an antenna device 101 and a transmission / reception unit 102. The antenna device 101 includes a first antenna 103, a second antenna 104, a selection unit 105, a control unit 106, and a voice call identification unit 107.

  The transmission / reception unit 102 performs radio transmission / reception of signals via the antenna selected by the selection unit 105 from the first antenna 103 and the second antenna 104.

  The selection unit 105 selects one of the first antenna 103 and the second antenna 104 as an antenna to be used for wireless transmission / reception according to the electric control by the control unit 106 and electrically connects the selected antenna and the transmission / reception unit 102. Connect (that is, switch the antenna used for wireless transmission / reception to one of the first antenna 103 and the second antenna 104). As a result, the received signal input to the selected antenna is transmitted to the transmitting / receiving unit 102, and the transmission signal from the transmitting / receiving unit 102 is transmitted to the selected antenna and wirelessly transmitted via the antenna. The selection means 105 includes a high-frequency switch such as a well-known semiconductor switch.

  The voice call identification unit 107 identifies the voice call state and the non-voice call state of the transmission / reception unit 102 while constantly monitoring the transmission / reception unit 102 and sends an identification signal indicating the identification result to the control unit 106. The voice call identification unit 107 detects the voice call state of the transmission / reception unit 102 as the portable radio telephone terminal device 100 (antenna device 101) is close to the human head.

  The first antenna 103 is designed so as to obtain a good SAR characteristic even at the maximum transmission power. The second antenna 104 is an antenna having a higher antenna gain, although the SAR characteristics are not as good as those of the first antenna 103.

  The control means 106 receives the identification signal from the voice call identification means 107 and, based on this identification signal, selects to switch the antenna used for wireless transmission / reception to one of the first antenna 103 and the second antenna 104 A control signal is sent to the means 105. The control means 106 outputs a control signal so that the second antenna 104 having a high antenna gain is selected by the selection means 105 when the transmission / reception unit 102 is in a non-voice call state. As a result, good reception quality is maintained even in a bad environment with a low reception power level. On the other hand, when the transmission / reception unit 102 enters a voice call state, the control unit 106 outputs a control signal that causes the selection unit 105 to select the first antenna 103.

  In the above embodiment, the SAR value during a call can be maintained at a good value without reducing the antenna gain of the antenna itself. Further, since it is not necessary to keep the distance between the portable radio telephone terminal device 100 (antenna device 101) and the human head large, the size of the portable radio telephone terminal device 100 (antenna device 101) increases as the number of antennas increases. There is a big merit for. Further, since the antenna is switched only at the start of the voice call state, the baseband processing such as transmission power control is hardly adversely affected, and the SAR during the voice call is ensured while ensuring good communication quality. It is possible to keep the value good.

  In the present embodiment, the case where the number of antennas is two has been described. However, the present invention can be implemented even when the number of antennas is three or more. In addition, even if the number of antennas is one, the method of controlling the SAR characteristics by directivity control or the like can be implemented by changing the antenna performance instead of changing the antenna. Further, in this embodiment, the voice call identification unit 107 monitors the transmission / reception unit 102 to identify the voice call state and the non-voice call state of the transmission / reception unit 102. It goes without saying that a voice call state and a non-voice call state of the transmission / reception unit 102 may be identified by monitoring a baseband unit (not shown).

[Second Embodiment]
Next, a second embodiment (mobile radio telephone terminal device 200) will be described with reference to FIG. 2 having the same functions as those in the first embodiment shown in FIG. 1 are denoted by the same reference numerals, and description thereof is simplified or omitted.

  As shown in FIG. 2, the portable radio telephone terminal device 200 includes an antenna device 201 and a transmission / reception unit 102. The antenna device 201 includes a first antenna 103, a second antenna 104, a third antenna 108 that is designed to obtain good SAR characteristics even at the maximum transmission power, as with the first antenna 103, and selection means. 105, control means 106, voice call identification means 107, measurement means 109 for measuring the reception power level of the signal selected by the antenna selected by the selection means 105 from the transmission / reception unit 102, and measurement of the reception power level by the measurement means 109 Storage means 110 for storing the results.

  For example, the measuring unit 109 measures the actual received power level when the transmission / reception unit 102 receives a radio signal via any one of the first antenna 103, the second antenna 104, and the third antenna 108, And the measurement result is memorize | stored in the memory | storage means 110 (Namely, the measurement result of the received power level of the applicable antenna memorize | stored in the memory | storage means 110 is updated).

  Except for the third antenna 108, the measuring means 109, and the storage means 110, the components of the portable radio telephone terminal apparatus 200 are the same as those of the portable radio telephone terminal apparatus 100, and their contents can be easily inferred. Therefore, the description thereof is omitted.

  In the portable radio telephone terminal device 200, the antenna having the highest received power level is selected from the first antenna 103, the second antenna 104, and the third antenna 108 during non-voice call. For this reason, it is possible to maintain good transmission quality. Moreover, in the mobile radio telephone terminal device 200, during a voice call, the reception power level is high among the measurement results stored in the storage means 110 from among the first antenna 103 and the third antenna 108 having good SAR characteristics. Select an antenna. For this reason, it is possible to maintain good SAR characteristics without impairing transmission quality even during a voice call. Further, since it is not necessary to lower the antenna gain in order to reduce the SAR, the transmission quality is not impaired, and since it is not necessary for all the antennas to satisfy the SAR characteristics, the portable radio telephone terminal device 200 can be downsized. is there.

  In the portable radio telephone terminal device 200, the number of antennas is three, and two of them have good SAR characteristics. However, the present invention is not limited to this. Even if there is only one antenna, if the antenna has a plurality of characteristics by control, it can be similarly implemented by switching the antenna characteristics instead of switching the antennas. Further, the present invention can be similarly implemented even in a configuration including a plurality of antennas having one or more characteristics.

  The measurement means 109 has been described as detecting the reception power level of each antenna from the transmission / reception unit 102, but the present invention is not limited to this, and the RSSI (Received Signal Strength Indicator), RSCP of each antenna is not limited thereto. This can also be realized by measuring parameters indicating transmission quality such as (Received Signal Code Power), SIR (Signal-to-Interference Ratio), BER (Bit Error Rate), and BLER (Block Error Rate).

  The first embodiment (that is, the portable radio telephone terminal device 100) and the second embodiment (that is, the portable radio telephone terminal device 200) of the portable radio communication device according to the present invention have been described above. A mobile radiotelephone terminal device (hereinafter referred to as a “mobile phone”) 10 is shown as an example of the external appearance.

  The mobile phone 10 has an operation unit (key operation unit) 11 that is operated when inputting characters including numbers and symbols or selecting various functions on the main body, and by operating the operation unit 11. A display device 12 such as a liquid crystal display device for displaying the generated character data, a speaker 13 for emitting sound, an external antenna 14 that can be expanded and contracted, a sound collecting microphone 15, an internal antenna (not shown) ) And. The circuits and the like shown by the functional blocks shown in FIGS. 1 and 2 are accommodated in the main body of the mobile phone 10. For example, according to the second embodiment shown in FIG. 2, the mobile phone 10 forms a first antenna 103, a second antenna 104, and a third antenna 108 as an antenna group together with a plurality of internal antennas (not shown). However, it goes without saying that the antenna group may be formed by only a plurality of internal antennas (not shown).

  In the description of the first embodiment (that is, the portable wireless telephone terminal device 100) and the second embodiment (that is, the portable wireless telephone terminal device 200) of the portable wireless communication device according to the present invention, the absorption to the human head is performed. As an example of the reference electric energy of the electromagnetic wave to be used, the SAR characteristic which is the reference applied to the portable radio telephone terminal device is used, and the voice call state is given as an example to indicate the state of being close to the human head. The present invention is not limited to a portable radio telephone terminal device, and is not limited to a voice call state, and may be provided with a portable radio communication device and used close to a human head. The present invention can be applied to all the obtained electronic devices. For example, the present invention can be effectively applied to an imaging apparatus such as a digital camera or a digital video camera described as the prior art that includes a portable wireless communication apparatus.

  The antenna device of the present invention and the portable wireless communication device equipped with the antenna device are capable of improving transmission quality without greatly hindering downsizing of the antenna device and downsizing of the portable wireless communication device equipped with the antenna device. Since electromagnetic wave radiation to the human head can be reduced without loss, it is useful for all electronic devices that have a wireless communication function and can be considered to be used close to the human head.

The block diagram which shows the system configuration | structure in 1st Embodiment of the portable radio | wireless communication apparatus which concerns on this invention. The block diagram which shows the system configuration | structure in 2nd Embodiment of the portable radio | wireless communication apparatus which concerns on this invention. 1 is a front view of a portable wireless telephone terminal device which is an example of a portable wireless communication device according to the present invention.

Explanation of symbols

100 portable wireless telephone terminal device (mobile wireless communication device)
200 Mobile wireless telephone terminal device (mobile wireless communication device)
DESCRIPTION OF SYMBOLS 101 Antenna apparatus 201 Antenna apparatus 102 Transmission / reception part 103 1st antenna 104 2nd antenna 105 Selection means 106 Control means 107 Voice call identification means (identification means)
108 Third antenna 109 Measuring means 110 Storage means

Claims (7)

An antenna device that can be mounted on a portable wireless communication device,
An antenna group consisting of a plurality of antennas;
Selecting means for selecting an antenna to be used for wireless transmission / reception from the antenna group;
Control means for controlling the antenna selection operation of the selection means;
Identifying means for identifying whether the antenna device is close to a human head;
With
An antenna apparatus in which the control unit sends a control signal to the selection unit so that the selection unit selects the antenna to be used based on the identification result by the identification unit. The antenna device according to claim 1,
The antenna group includes at least one antenna in which the amount of electromagnetic waves absorbed by the human head is smaller than a predetermined reference power amount,
The control means is configured such that, when the identification means identifies that the antenna device is close to the human head, the power of electromagnetic waves absorbed by the human head is smaller than a predetermined reference power An antenna device for transmitting a control signal to the selection means so as to select an antenna. The antenna device according to claim 2,
Measuring means for measuring the received power level of the signal by the antenna selected by the selecting means;
Storage means for storing a measurement result of the received power level by the measurement means;
Further comprising
The control means is configured such that, when the identification means identifies that the antenna device is close to the human head, the power of electromagnetic waves absorbed by the human head is smaller than a predetermined reference power An antenna device for transmitting a control signal to the selection means so as to select an antenna having the highest received power level in the measurement result stored in the storage means from among the antennas. The antenna device according to claim 2 or 3, wherein
The identification means is configured such that the transmitting / receiving unit of the portable wireless communication device that is electrically connected to the antenna to be used and wirelessly transmits / receives a signal through the antenna is in a voice call state, and the antenna device Detecting the proximity of the head and sending an identification signal to the control means, and the control means determines that the electric energy of the electromagnetic wave absorbed by the human head according to the identification signal is a predetermined reference electric energy An antenna device for sending a control signal to the selection means so as to select a smaller antenna. The antenna device according to claim 2 or 3,
A transmission / reception unit that is electrically connected to the antenna to be used and performs wireless transmission / reception of signals via the antenna;
A portable wireless communication device. The portable wireless communication device according to claim 5,
The identification means detects that the transmission / reception unit is in a voice call state as the portable wireless communication device is close to the human head, and sends an identification signal to the control means, and the control A portable wireless communication apparatus, wherein the means transmits a control signal to the selection means so as to select an antenna in which the electric energy of the electromagnetic wave absorbed by the human head is smaller than a predetermined reference electric energy according to the identification signal.   A portable radio telephone terminal device which is the portable radio communication device according to claim 5 or 6.

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