JP2006270534A - Radio communications equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain proper radiation characteristics, according to the use state of radio communications equipment such as call standby, voice communication, etc. <P>SOLUTION: The radio communications equipment includes a first antenna and a second antenna for receiving radio waves mutually independently at standby in the radio communications equipment, and at the time of communication, a phase circuit for delaying the phase of the radio wave received by the second antenna, so as to connect to the first antenna. At standby, the first antenna and the second antenna are operated as a diversity antenna having no directivity, while at communication, the first antenna is combined with the second antenna, so as to operate as an array antenna having directivity. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a wireless communication apparatus, and more particularly to a mobile phone having a plurality of antennas.

  A general mobile phone is shown in FIG. The foldable mobile phone 100 includes an upper housing 101 and a lower housing 102, and is connected to be opened and closed by a hinge. The upper casing 101 is provided with a display 104 for displaying various display information, and a speaker 105 for outputting the voice and ringing sound of the other party, in addition to the antenna 103 for transmitting and receiving with the base station. The lower housing 102 is provided with a plurality of operation keys 106 for inputting telephone numbers and operation signals, and a microphone 107 for collecting user's voice during a call.

  FIG. 9 shows a usage state of a conventional mobile phone. FIG. 9A shows a standby state, in which the upper housing is folded with respect to the lower housing, that is, a closed state. At this time, since the use state of the mobile phone is not specified for the mobile phone, the mounted antenna 103 is required to be non-directional.

  On the other hand, FIG. 9B shows a voice call state, and shows a state where the upper housing is opened at a predetermined angle with respect to the lower housing, that is, an open state. At this time, the mobile phone 100 specifies the use state of the mobile phone to some extent such that the microphone 107 is placed near the mouth and the speaker 105 is placed near the ear. It should be noted that the positional relationship is such that the human head is close to the mobile phone during a voice call.

  As described above, since the omnidirectional antenna is used in the mobile phone, it is possible to receive radio waves arriving from all directions during standby. However, when a voice call is made, radiation is caused by the proximity of the human head. Is absorbed by the head, leading to a decrease in radiation efficiency and an increase in human body specific absorption rate (SAR).

  The radiation pattern at this time is shown in FIG. As shown in FIG. 10, during a voice call, a radiation pattern is formed around the mobile phone, and a part of the radiation pattern on the human head side (shown by hatching) is absorbed by the human head, Radiation occurs.

Patent document 1 exists as a mobile phone that solves the above problem.
Japanese Patent Laid-Open No. 2004-128847 This Patent Document 1 includes four or more antenna elements, estimates the arrival direction of a received signal during a voice call, and sets the directivity pattern of the antenna array based on the estimated arrival direction The communication performance during a call can be improved.

  However, in the above-described conventional mobile phone, the number of antennas is limited in order to provide antennas while maintaining a small casing, so the beam direction is limited. In other words, it is difficult to form an effective directivity pattern during standby when the usage state of the mobile phone is not specified. Further, since the array controller and the beam algorithm are complicated, the circuit portion becomes complicated.

  An object of the present invention is to obtain good radiation characteristics in accordance with the use state of a wireless communication device such as in standby and during voice calls.

The wireless communication apparatus according to the present invention delays the phase of the first and second antennas that receive radio waves independently from each other during standby, and the radio waves received by the second antenna during a call. A phase circuit connected to the first antenna, and when the Matsui family, the first antenna and the second antenna are operated as non-directional diversity antennas. The second antenna is combined to operate as a directional array antenna.

In addition, the wireless communication device according to the present invention is characterized in that a microphone or a speaker is disposed on the second antenna side surface of the housing.
The wireless communication apparatus according to the present invention is characterized in that the first antenna and the second antenna are separated from each other by a quarter wavelength of a use frequency.

  The wireless communication apparatus of the present invention has the circuit configuration of FIG. 2A and the radiation pattern of FIG. That is, the omnidirectional first antenna 2 is connected to the transmission source, while the similarly non-thought-like second antenna 3 is connected to the transmission source via the phase circuit 10. In this phase circuit, the received radio wave is delayed in phase by 90 ° and synthesized with the radio wave received by the first antenna 2 to function as an array antenna.

At this time, the maximum radiation walk is on the first antenna side in the direction connecting the two antennas, and the maximum gain is obtained by directivity synthesis when the gain of the original omnidirectional antenna is 1.
G _max = | 1 + j | ² = 2 (1)
Therefore, it is possible to have a gain of 2 times. The radiation pattern at this time is shown in FIG. The cardioid characteristic has a null point on the second antenna 3 side and a maximum radiation direction on the first antenna 2 side. In the figure, the broken line shows the original radiation pattern of each antenna before antenna combination, and the solid line shows the radiation pattern after synthesis.

  According to the wireless communication device of the present invention, while realizing a reduction in the size of the housing, the diversity operation is performed with the omnidirectional antenna during standby, and the directivity is controlled by the array antenna operation during a call. Good radiation characteristics according to the state of use can be obtained, and radio waves radiated to the human body can be reduced.

  Furthermore, the speaker is arranged on the side surface of the housing on the second antenna side (null point side), which contributes to downsizing of the device.

  Furthermore, the microphone and the speaker are arranged on the second antenna side (null point side) side surface of the housing, which contributes to shortening of the apparatus in the longitudinal direction.

  In the following embodiments, a folding mobile phone will be described as an example of a wireless communication device. The present invention is not limited to a foldable mobile phone, but can be applied to any mobile phone type such as a straight type, a slide type, a turn type, and a biaxial hinge type.

  Furthermore, even in the case of a mobile type personal computer, PDA (Personal Digital Assistant), etc., two omni-directional antennas are provided, and wireless communication is performed such that the device is brought close to the human body without using a headset. Any communication device can be applied.

  FIG. 1 is a perspective view of a mobile phone according to the present invention.

  FIG. 3 is an external view of a mobile phone according to the present invention.

  FIG. 4 is a diagram showing a circuit configuration of the antenna unit of the mobile phone according to the present invention.

  FIGS. 5A and 5B are diagrams showing a use state of the mobile phone according to the present invention when the mobile phone is in standby, FIG. 5A is an external view, and FIG. 5B shows a circuit configuration.

  6A and 6B are diagrams showing a usage state of the cellular phone according to the present invention during a voice call. FIG. 6A is an external view, and FIG. 6B shows a circuit configuration.

  FIG. 7 is a diagram showing a radiation pattern of the mobile phone according to the present invention.

  In addition, what attached | subjected the same code | symbol through FIG. 1 thru | or FIG. 7 each shows the same target object.

  As shown in FIGS. 1 and 3, the mobile phone 1 of the present invention is composed of an upper housing 1a and a lower housing 1b, and can be folded via a hinge. The upper casing 1a is provided with a display 4 on the folded inner surface side.

  The display 4 displays icons such as a battery remaining amount display, a reception level, and a manner mode in the upper area and the lower area, and displays a standby screen, an incoming screen, a browser, and the like.

  In addition, a first antenna 2 and a second antenna 3 are provided in parallel to the lateral direction of the upper housing 1a. The first and second antennas 2 and 3 are both omnidirectional antennas and protrude from the tip of the upper casing 1a that is not on the hinge side. The first antenna 2 and the second antenna 3 are separated by a distance of about ¼ wavelength of the used frequency, for example, a distance of about 37 mm if the used frequency is in the 2 GHz band.

  The speaker 5 is provided on the second antenna side surface 1a-1 of the upper housing 1a, in other words, on the null point side surface, and when talking with a mobile phone in hand, it is just near the ear of the person who operates it. The speaker 5 is positioned. The speaker 5 outputs the voice of the other party during a voice call or a ringing sound accompanying an incoming call.

  In the lower housing 1b, a plurality of operation keys 6 are arranged in an aligned manner on the folded inner surface side. By operating from this operation key 6, a telephone number and characters are input and menu items are executed. The operation keys 6 include a numeric key 6a, a power on / end key 6b, a voice call start key 6c, a clear key 6d, a multi-cursor key 6e, a menu key 6f, and the like.

  An external connection terminal 8 is provided at the tip of the lower housing 1b that is not on the hinge side, and an AC adapter or the like is connected thereto. A rear cover 9 is attached to the back surface of the lower housing 1b, that is, the surface opposite to the surface on which the operation keys 6 are provided. When the rear cover 9 is removed, a battery pack and a USIM card (not shown) are set.

  A microphone 7 that collects the voice of the operator during a call is provided on the second antenna side surface 1b-1 of the lower housing 1b, in other words, on the null point side surface. When making a call, the microphone 7 is positioned near the mouth of the person who operates.

  As shown in FIG. 4, the antenna unit circuit configuration of the mobile phone according to the present invention is such that the first antenna 2 is connected to ANT 1 of the antenna switch 13, and the second antenna 3 is connected to the antenna switch 13 via SW 1 11. Connected to ANT2. Further, the first antenna 2 and the second antenna 3 are connected to each other via the SW2 12 and the phase circuit 10.

  The phase circuit 10 is for delaying the phase of the radio wave received from the second antenna 3 by 90 °, and the antenna switch 13 is connected to a radio unit (not shown).

Next, the operation of the mobile phone according to the present invention will be described for each use state.
(A) During standby Since the use state of the mobile phone is not specified during standby, radio waves coming from all directions must be received. Furthermore, in order to ensure a stable radio wave environment even when carried around, multipath fading due to reflection and diffraction of incoming radio waves on buildings and the earth must be reduced.

  In order to realize the former, there is a method of making the mounted antenna non-directional, and in order to realize the latter, there is a method of diversity reception using two antennas.

  FIG. 5A shows the usage state of the mobile phone of the present invention when it is on standby.

  The two antennas (first antenna 2 and second antenna 3) are originally omnidirectional antennas. In addition, since each of them is traversed in a spatially separated place, it is possible to perform a diversity operation by sending received radio waves individually to the antenna switch 13.

  The circuit configuration of the antenna portion at this time is shown in FIG.

  By turning on SW1 11 between the second antenna 3 and the antenna switch 13, the second antenna 3 is connected to ANT2 of the antenna switch 13, and SW2 12 between the first antenna 2 and the second antenna 3 is connected. Is turned off to electrically disconnect the first antenna 2 and the second antenna 3.

Therefore, it is possible to reduce fading by sending radio waves received by two spatially separated antennas 2 and 3 to the antenna switch 13 individually and independently and receiving diversity (DIV reception). Therefore, it is possible to secure a stable radio wave environment during standby.
(B) At the time of voice call The usage state at the time of voice call is specified to some extent such as placing the microphone near the mouth and the speaker near the ear, so the mounted antenna is omnidirectional There is no need. Further, the human head is brought close to the mobile phone, and part of the radiation is absorbed by the head, leading to a decrease in radiation efficiency and increasing the human body specific absorption rate (SAR).

  The biggest problem in voice calls is the latter decrease in radiation efficiency and increase in SAR.

  Only during voice calls, the mounted antenna does not need to be omnidirectional as in the former. To solve the latter, the directivity of the mounted antenna is controlled to Radio wave emissions must be reduced.

  FIG. 6A shows the usage state of the mobile phone of the present invention during a voice call.

  Hold the front surface of the mobile phone 1, that is, the surface on which the operation keys are provided and the back surface of the mobile phone 1, and the speaker 5 provided on the side surface 1 a-1 of the upper housing 1 a near the ear and the side surface of the lower housing 1 b By placing the microphone 7 provided in 1b-1 in the vicinity of the mouth, the surface connecting the two antennas 2 and 3 is in a state perpendicular to the human head.

  The circuit configuration of the antenna portion at this time is shown in FIG.

  By turning off SW11 between the second antenna 3 and the antenna switch 13, the second antenna 3 and the antenna switch 13 are electrically disconnected. The first antenna 2 and the second antenna 3 are electrically connected by turning on SW2 12 between the first antenna 2 and the second antenna 3, and the second circuit 3 is connected via the phase circuit 10. The phase of the antenna 3 is delayed by 90 ° from that of the first antenna 2.

  Furthermore, since the distance between the two antennas is about 1/4 wavelength of the frequency used, for example, 37 mm away when the frequency used is 2 GHz, the two antennas 2 and 3 can be combined to operate as an array antenna. become.

  At this time, as shown by the radiation pattern in FIG. 7, the directivity has a null point in the direction of the human body and a high gain in the direction opposite to the human body (about twice as much as in the case of one antenna). Has cardioid properties.

  Here, some examples of ON / OFF automatic control of SW1 11 and SW2 12 are conceivable. In the first example, the opening / closing operation of the casing is detected and the diversity reception of the omnidirectional antenna and the directional array antenna are switched.

  That is, since the default setting of SW1 11 and SW2 12 is standby, SW1 11 is turned on and SW2 12 is turned off. When the incoming signal from the base station is received and it is detected that the casing has been operated from the closed state to the open state, SW1 11 is automatically turned off and SW2 12 is automatically turned on. Just keep it.

  Folding-type mobile phones usually have a built-in electromagnetic open / close switch to control the power on / off of the display. Therefore, it is necessary to provide special detection means by using the signal from the open / close switch. Absent.

  If this open / close switch is a slide type, a slide open / close detection switch may be used, and if it is a turn type, a turn open / close detection switch may be used.

  In the second example, when the voice call start key 6c is pressed, the diversity reception of the omnidirectional antenna and the directional array antenna are switched. Since the default setting of SW1 11 and SW2 12 is standby, SW1 11 is turned on and SW2 12 is turned off.

  When receiving an incoming signal from the base station and detecting that the operator has pressed the voice call start key 6c, the SW1 11 is automatically turned off and the SW2 12 is turned on automatically. Just keep it.

  In this example, the diversity reception and the directional array antenna can be switched to the omnidirectional antenna even when the mobile phone is in the open state, so that there is an effect that the mobile phone is not affected by the open / closed state of the mobile phone.

  Furthermore, regardless of the type of mobile phone, for example, straight type, folding type, slide type, turn type, etc., diversity reception and directional array antennas can be switched to omnidirectional antennas. There is also an effect that it can be applied to a telephone.

  As a modified example of the second example, if the any key answer function is set to be effective even if the cellular phone is not the voice call start key 6c, the key pressed at the time of the any key answer is detected. It is also possible to control so that SW1 11 is automatically switched from ON to OFF and SW2 12 is automatically switched from OFF to ON.

  Furthermore, another effect can be obtained by arranging the speaker on the side surface as in the present invention. That is, since the speaker is exposed even when the cellular phone is folded, it is not necessary to provide a standby speaker such as a rear speaker, and the cellular phone can be downsized.

  Furthermore, according to the present invention, the configuration of the antenna unit can be simplified.

The perspective view of the mobile telephone by this invention Diagram showing the composition of two antennas External view of mobile phone according to the present invention According to the present invention, the antenna unit circuit configuration of the mobile phone State of use of the mobile phone according to the present invention during standby Usage state of a cellular phone according to the present invention during a voice call Radiation pattern of a mobile phone according to the present invention The figure which shows the conventional portable telephone Usage status of conventional mobile phones Radiation pattern of conventional mobile phone

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Mobile telephone 1a ... Upper housing | casing 1b ... Lower housing | casing 2 ... 1st antenna 3 ... 2nd antenna 4 ... Display device 5 ... Speaker 6 ... Operation key 7 ... Microphone 10 ... Phase circuit 11 ... SW1
12 ... SW2
13 ... Antenna switch

Claims (3)

In a wireless communication device,
A first antenna that receives radio waves independently of each other when waiting, a second antenna,
A phase circuit that delays the phase of the radio wave received by the second antenna during a call and connects the first antenna to the first antenna;
During the standby, the first antenna and the second antenna are operated as non-directional diversity antennas,
A wireless communication apparatus, wherein during the call, the first antenna and the second antenna are combined to operate as a directional array antenna. The wireless communication apparatus according to claim 1, wherein a microphone or a speaker is disposed on a side surface on the second antenna side of the housing. The wireless communication apparatus according to claim 1, wherein the first antenna and the second antenna are separated from each other by a quarter wavelength of a use frequency.

Images