JP2001352387A - Mobile phone - Google Patents

Abstract

(57) [Problem] To provide a mobile phone capable of reducing electromagnetic energy radiated from the inside of a mobile phone using a plurality of radio signals to the human head. SOLUTION: A mobile phone 102 ₁ includes a printed circuit board on which a receiving circuit and a transmitting circuit are mounted, a shield case 4A for suppressing interference between the printed circuit board and the antenna 1, and a human head on the surface of the shield case 4A during a call. There are radio wave absorbers 31 ₁ and 32 ₁ which are in close contact with the region 49 located on the side of the unit. The transmission circuit selectively generates a radio signal of the first or second frequency. Wave absorber 31 _1, the magnetic loss in the first frequency comprises a material which is the maximum, the surface current of the shield case 4A at the time of transmission of the first frequency of the radio signals is disposed in the region of maximum. Radio wave absorber 31
Reference numeral ₂ includes a material having the largest magnetic loss at the second frequency, and is arranged in a region where the surface current of the shield case 4A is maximized when transmitting a wireless signal of the second frequency.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a portable telephone.

[0002]

2. Description of the Related Art FIG. 1 is a schematic configuration diagram showing a portable telephone. This mobile phone 100 is a mobile phone 100
Is in contact with the head (human head) 91 of the user 90.
The mobile phone 100 includes an antenna 1, a feeder unit 2,
Printed circuit board 3, shield case 4, components 5A, 5
B, a transmitter 6, a keypad 7, a liquid crystal display 8,
It has a receiver 9 and an insulating casing 10.

The transmitting / receiving antenna 1 protrudes from the upper end of the housing 10, and transmits radio waves to the base station during transmission, and receives radio waves from the base station during reception. The antenna 1 is a retractable antenna that can expand and contract in the longitudinal direction of the housing 10.

On one surface of the printed circuit board 3, for example,
Semiconductor integrated circuit (IC), transistor, capacitor,
A component 5A such as a resistor is mounted. Printed circuit board 3
On the other side, a component 5B such as an IC, a transistor, a capacitor, and a resistor is mounted. The printed circuit board 5 is formed by the printed circuit board 3 and the components 5A and 5B.
Is configured. The printed circuit board 5 includes a switching circuit, a control circuit, a transmission circuit, and a reception circuit. The transmission circuit and the reception circuit are connected to the antenna 1 via a switching circuit and a feeder unit 2.

[0005] The housing 10 is provided with a hole 6H for the transmitter 6, a hole 9H for the receiver 9, a window 8W for the liquid crystal display 8, and the like. The hole 6H is a mouthpiece, and the hole 9H is a earpiece. The housing 10 houses the printed circuit board 5, the shield case 4, the transmitter 6 and the receiver 9. The user 90 can see the display on the liquid crystal display 8 through the window 8W.
The user 90 can hear the output sound of the receiver 9 through the hole 9H. The sound uttered by the user 90 is supplied to the transmitter 6 through the hole 6H. The transmitter 6, to which a sound such as the uttered sound of the user 90 is input, generates a first audio signal corresponding to the sound.

[0006] The printed circuit board 5 converts the first audio signal into a first radio signal, and the first radio signal is transmitted from the antenna 1 to the base station. This base station transmits a second wireless signal to mobile phone 100. The printed circuit board 5 converts the second wireless signal input to the antenna 1 into a second audio signal and supplies the second audio signal to the receiver 9. The receiver 9 outputs a sound corresponding to the second audio signal and supplies the sound to the user's 90 ear. In addition, the printed circuit board 5,
The circuits such as the transmitter 6, the receiver 9, and the liquid crystal display 8 are supplied with driving power from a driving power supply (not shown) (for example, a battery or a battery) in the mobile phone 100.

[0007] The keypad 7 has dial buttons or numeric keys. Information such as a telephone number is input by the user 90 to the keypad 7. The liquid crystal display 8 displays various information. For example, the telephone number entered on the keypad 7 is displayed.

[0008] The shield case 4 is connected to the ground layer of the printed circuit board 5, and the printed circuit board 5 is designed to suppress electromagnetic interference between the printed circuit board 5 and the antenna 1.
Is surrounded. The surface of the shield case 4 has conductivity.

In recent years, local absorption guidelines for mobile phones have been established in Japan. As an evaluation amount of local absorption, there is SAR (Specific Absorption Rate) indicating the power of electromagnetic energy absorbed per unit mass. For example,
Japanese local absorption guidelines stipulate that the peak value of the 10-gram tissue average SAR does not exceed 2 W / kg.

[0010] "Reduction of local SAR and control of communication characteristics by controlling the surface current of a mobile phone" (Journal of the Japan Society of Applied Magnetics, Vol.23, No.10, pp.2005-2008 (1999)) It is described that a local SAR is reduced by attaching a ferrite sheet to a metal housing of a mobile phone.

[0011]

The SAR tends to increase as the transmission output of the mobile phone increases, and to increase as the distance between the radio wave radiation source of the mobile phone and the human body decreases.
In a mobile phone, the position where the SAR (local SAR) becomes highest may be a portion other than the antenna, for example, near the shield case. This is due to the fact that the shield case functions as a part of the antenna and that the shield case is closer to the human head than the antenna during a call.

FIG. 2 is a schematic explanatory view showing a mobile phone 101 in which a radio wave absorber is attached to the mobile phone 100 of FIG. In the mobile phone 101 of FIG. 2, the same components as those of the mobile phone 100 of FIG. 1 are denoted by the same reference numerals, and the description of the same components will be omitted as appropriate.
In this mobile phone 101, the sheet-like radio wave absorber 11
Are attached to the human head 91 side of the shield case 4 via an insulating adhesive 12. Insulating adhesive 12
Is an adhesive made of, for example, only synthetic resin.

There is a type of portable telephone that performs wireless communication using a plurality of wireless signals. The plurality of wireless signals,
For example, a radio signal of a first frequency (for example, about 900 MHz) and a second signal (for example, about 1.8 GHz)
z) is a wireless signal. In this case, if a radio wave absorber that mainly absorbs a radio wave of one of the first and second frequencies is used as the radio wave absorber 11, the absorption of the radio wave of the other frequency is reduced, and the SAR reduction is reduced. Is not preferred.

An object of the present invention is to provide a portable telephone capable of reducing electromagnetic energy radiated from the inside of the portable telephone using a plurality of frequency radio signals toward the human head.

[0015]

A portable telephone according to the present invention comprises an antenna, a transmitter for generating a first audio signal corresponding to an input sound, and a first transmitter from the transmitter. A transmission circuit that modulates an audio signal to generate a first wireless signal, and transmits the first wireless signal via the antenna;
A receiving circuit that demodulates a second wireless signal that is a second wireless signal that is input to the antenna and that modulates a second audio signal to generate the second audio signal; A receiver for outputting a sound corresponding to the second audio signal, a printed circuit board on which the receiving circuit and the transmitting circuit are mounted, and the printed circuit board so as to suppress electromagnetic interference between the printed circuit board and the antenna. A portable having a shield case surrounding a circuit board, and an insulative housing for storing the printed circuit board, the first radio wave absorber, the second radio wave absorber, the shield case, the transmitter and the receiver. A telephone, wherein the first wireless signal includes a first frequency wireless signal and a second frequency wireless signal;
The transmission circuit selectively generates a radio signal of the first or second frequency, and the first and second radio wave absorbers are provided between the shield case and the housing, and are used for communication. Sometimes placed in a region located on the head side of the human body, the first radio wave absorber has a magnetic loss or an imaginary part of complex magnetic permeability at or near the first frequency that is the largest or substantially the largest. And a first magnetic loss material is disposed between the first maximum area of the shield case where the surface current is maximum or substantially maximum when transmitting the wireless signal of the first frequency and the housing. Wherein the second radio wave absorber contains a second magnetic loss material in which the magnetic loss or the imaginary part of the complex magnetic permeability is maximum or substantially maximum at or near the second frequency, Transmitting the radio signal of the second frequency The surface current of the shield case is disposed between the second maximum area and the casing having a maximum or substantially maximum.

In the portable telephone according to the present invention, preferably,
The surface of the shield case has conductivity, and the first radio wave absorber is attached to the first maximum region and the peripheral region thereof on the surface of the shield case, The radio wave absorber is attached to the second maximum area and its peripheral area on the surface of the shield case.

In the portable telephone according to the present invention, more preferably, the first radio wave absorber is in close contact with the surface of the shield case, and the thickness of a portion in close contact with the first maximum region Is larger than the thickness of the portion that is in close contact with the peripheral region of the first maximum region.

In the mobile phone according to the present invention, more preferably, the second radio wave absorber is in close contact with the surface of the shield case, and the thickness of a portion in close contact with the second maximum region Is larger than the thickness of the portion that is in close contact with the peripheral area of the second maximum area.

In the portable telephone according to the present invention, preferably,
The first radio wave absorber is a molded product obtained by mixing a powder of the first magnetic loss material and a synthetic resin, and the second radio wave absorber is a molded product of the second magnetic loss material. It is a molded product formed by mixing powder and a synthetic resin.

In the portable telephone according to the present invention, for example, one of the first and second frequencies is approximately 800 MHz.
Hz or about 900 MHz, the first and second
Of about 1.8 GHz or about 2 GHz
Hz.

The portable telephone according to the present invention further includes, for example, a switching circuit interposed between the transmitting circuit and the receiving circuit and the antenna, wherein the switching circuit is mounted on the printed circuit board, The first wireless signal from the transmitting circuit may be supplied to the antenna, and the second wireless signal from the antenna may be supplied to the receiving circuit.

In the portable telephone according to the present invention, for example, the shield case includes a case made of an insulating material;
A conductive layer formed on a surface of the case; and the conductive layer is connected to a ground layer of the printed circuit board.

In the portable telephone according to the present invention, for example, the shield case may be made of a conductive material and connected to a ground layer of the printed circuit board.

Electromagnetic energy is absorbed by the radio wave absorber by disposing the first and second radio wave absorbers in the region between the shield case and the housing and located on the side of the human head during a call. SAR can be reduced.
The first electromagnetic wave absorber includes a first magnetic loss material having a magnetic loss or an imaginary part of a complex magnetic permeability at or near a first frequency at a maximum or substantially maximum. By arranging the first radio wave absorber between the housing and the first maximum area of the shield case where the surface current is maximum or substantially maximum when transmitting the wireless signal of the first frequency, the SAR Can be increased.

Further, the second radio wave absorber has a second magnetic loss material in which the magnetic loss or the imaginary part of the complex magnetic permeability is the maximum or substantially the maximum at or near the second frequency. By arranging the second radio wave absorber between the second maximum area of the shield case where the surface current is maximum or substantially maximum and the housing when transmitting the wireless signal of the second frequency, It is possible to increase the amount of SAR reduction.

[0026]

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

FIG. 3 is a schematic configuration diagram showing an embodiment of a portable telephone according to the present invention. This mobile phone 10
Numeral 2 is in contact with the head (human head) 91 of the user 90 of the mobile phone 102.

The mobile phone 102 includes an antenna 1, a feeder unit 2, a printed circuit board 3, and a shield case 4A.
, Parts 5A and 5B, a transmitter 6, a keypad 7,
It has a liquid crystal display 8, a receiver 9, a radio wave absorber 30, and an insulating casing 10. The length of the housing 10 in the longitudinal direction is, for example, about 12 cm.

The transmitting / receiving antenna 1 transmits radio waves to the base station during transmission, and receives radio waves from the base station during reception. The antenna 1 is a retractable antenna that can expand and contract from one end of the housing 10 in the longitudinal direction of the housing 10.

On one surface of the printed circuit board 3, for example,
Semiconductor integrated circuit (IC), transistor, capacitor,
A component 5A such as a resistor is mounted. Printed circuit board 3
On the other side, a component 5B such as an IC, a transistor, a capacitor, and a resistor is mounted. The printed circuit board 5 is formed by the printed circuit board 3 and the components 5A and 5B.
Is configured. The printed circuit board 5 includes a switching circuit (SW), a control circuit (CNT), a transmission circuit (TRS)
And a receiving circuit (RCV). The transmission circuit and the reception circuit are connected to the antenna 1 via a switching circuit and a feeder unit 2.

The housing 10 includes a printed circuit board 5, a shield case 4A, a radio wave absorber 30, a transmitter 6, and a receiver 9.
Is stored. The receiver 9 is arranged near one end of the housing 10. The transmitter 6 is arranged near the other end of the housing 10. The housing 10 has a transmitter 6
6H, a hole 9H for the receiver 9, a window 8W for the liquid crystal display 8, and the like. The hole 6H is a mouthpiece, and the hole 9H is a earpiece.

The user 90 can see the display on the liquid crystal display 8 through the window 8W. The user 90 can hear the output sound of the receiver 9 through the hole 9H. User 9
The sound uttered by 0 is supplied to the transmitter 6 through the hole 6H. The transmitter 6, to which a sound such as the uttered sound of the user 90 is input, generates a first audio signal corresponding to the sound.

[0033] The printed circuit board 5 converts the first audio signal into a first radio signal, and the first radio signal is transmitted from the antenna 1 to the base station. The first wireless signal is a first wireless signal.
The transmission circuit in the printed circuit board 5 selectively generates a radio signal of the first or second frequency f1 or f2, and a radio signal of the frequency f1 and a radio signal of the second frequency f2. . The mobile phone 102 is so-called dual-band compatible. For example, one of the first and second frequencies is about 800 MHz or about 900 MHz, and the other of the first and second frequencies is about 1.8
GHz or about 2 GHz.

The base station transmits a second
To transmit the wireless signal. The printed circuit board 5 converts the second wireless signal input to the antenna 1 into a second audio signal and supplies the second audio signal to the receiver 9. The receiver 9 outputs a sound corresponding to the second audio signal and supplies the sound to the user's 90 ear. The frequency of the second wireless signal is, for example, about 800 M
Hz or about 900 MHz, and about 1.8 GH
z or about 2 GHz. Circuits such as the printed circuit board 5, the transmitter 6, the receiver 9, the liquid crystal display 8, etc.
Driving power is supplied from a driving power supply (not shown) (for example, a battery or a battery) in the mobile phone 102.

The keypad 7 has dial buttons or numeric keys. Information such as a telephone number is input by the user 90 to the keypad 7. The liquid crystal display 8 displays various information. For example, the telephone number entered on the keypad 7 is displayed.

The shield case 4A is a printed circuit board 5
, And surrounds the printed circuit board 5 so as to suppress electromagnetic interference between the printed circuit board 5 and the antenna 1. The surface of the shield case 4A has conductivity.

The radio wave absorber 30 is arranged in a region between the shield case 4A and the housing 10 and on the side of the human head 91 during a call. The radio wave absorber 30 is adhered to the head side region 49 on the surface of the shield case 4A by the adhesive 21 and is in close contact therewith. The bonding surface of the radio wave absorber 30 is processed according to the surface of the shield case 4 </ b> A, and can adhere to the head side region 49.

For example, the shield case 4A is configured to have a case made of an insulating material and a conductive layer formed on the surface of the case, and the conductive layer is connected to the ground layer of the printed circuit board 5. It may be configured. As an example, a shield case 4A having a conductive layer formed by metal plating may be formed by plating a metal such as nickel on a plastic case. The shield case 4A may be made of a conductive material, and may be, for example, a metal case.

The radio wave absorber 30 has first and second magnetic loss materials. The magnetic loss material is made of, for example, ferrite, permalloy, sendust, stainless steel (stainless alloy), silicon steel, iron-based amorphous alloy, magnetic material, magnetic alloy, or the like. The radio wave absorber 30 is, for example,
Polyamide-based synthetic polymer, chlorinated polyethylene,
A molding obtained by mixing an insulating polymer compound such as a silicone resin, a phenol resin, or an epoxy resin with a powder of a magnetic loss material and curing the mixture into a desired shape may be used. The insulating polymer compound may be used as a binder material.

As an example, the electromagnetic wave absorber 30 may be a molded product obtained by adding a magnetic loss material powder to a synthetic resin and kneading the mixture, or adding a synthetic resin to the magnetic loss material powder and kneading the mixture. The powder may have a flat shape. Further, as the electromagnetic wave absorber 30, for example, a sintered body obtained by press-molding a powder of a magnetic loss material may be used.

In the mobile phone 102, the longitudinal dimension of the housing 10 is smaller than the wavelength of a radio signal used for radio communication, and the shield case 4A also functions as a part of the antenna. That is, the electric power supplied to the antenna 1 causes a current to flow on the surface of the shield case 4A, and the surface is excited.

FIG. 4 is a schematic block diagram of the portable telephone 102 of FIG. In the mobile phone 102 of FIG. 4, the switching circuit (SW) 2A and the control circuit (CNT) 5
0, a transmission circuit (TRS) 56, and a reception circuit (RC
V) 59 is composed of the components 5A and 5B in FIG. 3 and the printed circuit board 3, and the printed circuit board 5 in FIG.
It is installed in.

The utterance sound of the user 90 is input to the transmitter (MIC) 6, and the input sound is subjected to electroacoustic conversion to generate a first audio signal S1 corresponding to the input sound.
The transmission circuit 56 modulates the first audio signal S1 to convert it into a first wireless signal S11, and outputs the first wireless signal S11 to the switching circuit 2A. The first wireless signal S11 has a wireless signal S11 (f1) having a first frequency f1 and a wireless signal S11 (f2) having a second frequency f2. The transmission circuit 56 transmits the radio signals S11 (f1) and S11 (f2)
Is selectively generated.

The switching circuit 2A receives the first signal from the transmission circuit 56.
Of the antenna 1 via the feeder 2
To supply. The antenna 1 converts the first wireless signal S11 from an electric signal to a radio wave and sends the radio wave to a base station.

The antenna 1 receives the second radio signal S12 obtained by modulating the second audio signal S2, and supplies the second radio signal S12 to the switching circuit 2A via the feeder unit 2. The switching circuit 2A supplies the second radio signal S12 from the antenna 1 to the receiving circuit 59.

The receiving circuit 59 demodulates the second radio signal S12 to generate a second audio signal S2, and outputs the second audio signal S2 to the receiver 9. The receiver 9 outputs a sound corresponding to the second audio signal S2 by performing electroacoustic conversion on the second audio signal S2, and supplies the output sound to the user 90's ear.

The control circuit 50 is a controller for controlling the entire portable telephone 102, and controls the transmission circuit 56, the reception circuit 59, the switching circuit 2A, and the liquid crystal display 8. The control circuit 50 controls a transmission / reception sequence operation, a transmission / reception protocol, and the like, and is configured by, for example, a microcomputer.

The keypad 7 supplies input information input to the keypad 7 to the control circuit 50. Control circuit 50
Performs various signal processing based on input information of the keypad 7. The control circuit 50 controls the display of the liquid crystal display 8, and displays, for example, input information of the keypad 7 on the display screen of the liquid crystal display 8.

FIG. 5 is a characteristic diagram of the first and second magnetic loss materials. The vertical axis in the figure indicates the magnitude of the imaginary part μ ″ of the complex magnetic permeability μ (= μ′−jμ ″) of the magnetic loss material. This imaginary part μ ″ corresponds to the electromagnetic energy absorbed by the magnetic loss material.

The characteristic curve M1 shows the characteristic of the first magnetic loss material, which is maximum or substantially maximum near the first frequency f1. Here, the first frequency f1 is about 800 MHz or about 900 MHz. The first magnetic loss material is, for example, ferrite. This ferrite is, for example, nickel Ni, zinc Zn, and / or
Or, it contains copper Cu.

The characteristic curve M2 shows the characteristic of the second magnetic loss material, which is maximum or substantially maximum near the second frequency f2. Here, the second frequency f2 is set to about 1.8 GHz or about 2 GHz. The second magnetic loss material is, for example, permalloy, sendust, a stainless steel alloy, silicon steel, an iron-based amorphous alloy, or the like.

Since the radio wave absorber 30 has the first and second magnetic loss materials, the first and second frequencies f1,
The absorption of electromagnetic energy at f2 can be increased, and the amount of SAR reduction can be increased.

FIGS. 6 and 7 are schematic distribution diagrams illustrating the magnitude of radio waves radiated from the surface of the shield case 4A. The magnitude of the radio wave on the surface of the shield case 4A corresponds to the magnitude of the surface current. FIG.
In the mobile phone obtained by removing the radio wave absorber 30 from the mobile phone 102, the wireless signal S11 of the first frequency f1
The energy distribution at the time of transmission of (f1) is shown. Here, the first frequency f1 is about 900 MHz. FIG.
In a mobile phone obtained by removing the radio wave absorber 30 from the mobile phone 102, a radio signal S1 having a second frequency f2
1 shows an energy distribution at the time of transmission of 1 (f2). Here, the second frequency f2 is about 1.8 GHz.

The symbols a to k in the figure indicate the size of the SAR. The symbol a indicates that the SAR is 3.78 × 10 ⁻² mW.
/ G or more and less than 4.20 × 10 ⁻² mW / g. The code b indicates that SAR is 3.36 × 10 ⁻² mW
/ G or more and less than 3.78 × 10 ^-2 mW / g.

The code c indicates that SAR is 2.94 × 10 ^-2 m
The range is not less than W / g and less than 3.36 × 10 ⁻² mW / g. The code d indicates that the SAR is 2.52 × 10 ⁻² m
The range is not less than W / g and less than 2.94 × 10 ⁻² mW / g. The symbol e indicates that the SAR is 2.10 × 10 ⁻² m
The range is not less than W / g and less than 2.52 × 10 ⁻² mW / g.

The code f indicates that SAR is 1.68 × 10 ^-2 m
The range is not less than W / g and less than 2.10 × 10 ⁻² mW / g. The code g indicates that the SAR is 1.26 × 10 ⁻² m
The range is not less than W / g and less than 1.68 × 10 ⁻² mW / g.

The code h indicates that the SAR is 8.40 × 10 ⁻³ m
The range is not less than W / g and less than 1.26 × 10 ⁻² mW / g. The code i indicates that the SAR is 4.20 × 10 ⁻³ m
The range is not less than W / g and less than 8.40 × 10 ⁻³ mW / g. The code k is SAR of 4.20 × 10 ⁻³ m
The range below W / g is shown.

In the distribution diagram of FIG. 6, the surface current at the center of the upper half of the shield case 4A is large. The symbol a in FIG. 6 also indicates the maximum region where the surface current becomes maximum when transmitting the wireless signal of the first frequency f1. 7, the surface current on the upper right side of the shield case 4A is large. Note that reference symbol a in FIG.
Also shows the maximum area where the surface current is maximum when transmitting the wireless signal of the second frequency.

FIG. 6 and FIG. 7 have different energy distributions. Therefore, based on the surface current of the shield case 4A corresponding to the radio signals of the first and second frequencies f1 and f2, the first and second radio wave absorbers corresponding to the first and second frequencies f1 and f2 are changed. By arranging, it is possible to increase the amount of SAR reduction.

FIGS. 8 and 9 show the portable telephone 10 of FIG.
FIG. 2 is an explanatory view exemplifying a state in which a radio wave absorber 30 is attached to a human head side region 49 on the surface of a shield case 4A. 8 and 9, the housing 10 is omitted. FIG. 8A shows a mobile phone 102 ₁ which is the first embodiment of the mobile phone 102. Substantially upper half side of the surface of the shield case 4A in FIG. 8 (A), the Yes electric wave absorber 30 ₁ is a first embodiment of the radio wave absorber 30 is attached, in close contact.

[0061] In the radio wave absorber 30 ₁ has a rectangular or first wave absorber 31 ₁ substantially rectangular, and a rectangular or substantially rectangular second wave absorbers 32 _1, the first and Second
Radio wave absorbers 31 ₁ and 32 ₁ are arranged side by side.
The wave absorber 30 ₁ has a rectangular or substantially rectangular shape. The first radio wave absorber 31 ₁ contains a first magnetic loss material. The second electromagnetic wave absorber 32 ₁ contains a second magnetic loss material.

[0062] The first wave absorber 31 _1, of the approximately upper half side of the shield case 4A, is disposed in a central portion and left side portion. In this way, the first maximum area of the shield case 4A where the surface current is maximum or substantially maximum when transmitting the wireless signal of the first frequency f1,
Can be placed, the first wave absorber 31 ₁ between.

[0063] The second wave absorbers 32 _1, of the approximately upper half side of the shield case 4A, is disposed on the right portion. In this way, the second radio wave absorption is provided between the casing 10 and the second maximum area of the shield case 4A where the surface current is maximum or substantially maximum when transmitting the radio signal of the second frequency f2. it can be arranged body 32 _1.

In the portable telephone 102 _{1 of} FIG. 8A, the radio wave absorbers 31 ₁ and 32 ₁ can effectively absorb the electromagnetic energy of the radio signals of the first and second frequencies f 1 and f 2, It is possible to increase the amount of SAR reduction.

FIG. 8B shows a mobile phone 102 ₂ which is a _second embodiment of the mobile phone 102. The second half of the radio wave absorber 30 is provided at the center and the right side of the upper half of the surface of the shield case 4A of FIG.
Is attached wave absorber 30 ₂ a of the embodiment is in close contact.

[0066] In the radio wave absorber 30 _2, it has a rectangular or substantially rectangular first wave absorber 31 _2, and a rectangular or substantially rectangular second wave absorber 32 _2, first and Second
Of radio wave absorbers 31 ₂ and 32 ₂ are arranged side by side.
The wave absorber 30 ₂ has a rectangular or substantially rectangular shape. The first wave absorber 31 ₂ contains a first magnetic loss material. The second wave absorber 32 ₂ contains a second magnetic loss material.

[0067] The first wave absorber 31 _2, of the approximately upper half side of the shield case 4A, is arranged in the center portion. In this way, the first radio wave absorption is provided between the housing 10 and the first maximum area of the shield case 4A where the surface current is maximum or substantially maximum when transmitting the wireless signal of the first frequency f1. it is possible to arrange the body 31 _2. Also,
The first wave absorber 31 _2, the thickness of the portion 31A in close contact with the first maximum area is greater than the thickness of the portion 31B in close contact with the peripheral region of the first maximum area.

[0068] The second wave absorber 32 _2, of the approximately upper half side of the shield case 4A, is disposed on the right portion. In this way, the second radio wave absorption is provided between the casing 10 and the second maximum area of the shield case 4A where the surface current is maximum or substantially maximum when transmitting the radio signal of the second frequency f2. it is possible to arrange the body 32 _2. Also,
The second wave absorber 32 _2, the thickness of the portion 32A in close contact with the second largest area is greater than the thickness of the portion 32B in close contact with the peripheral region of the second maximum area.

In the portable telephone 102 _{2 of} FIG. 8B, the electromagnetic energy of the radio signals of the first and second frequencies f 1 and f 2 can be effectively absorbed by the radio wave absorbers 31 ₂ and 32 ₂ . It is possible to increase the amount of SAR reduction. In particular, by increasing the thickness of the portions 31A and 32A, the SAR reduction amount can be further increased.

FIG. 9A shows a mobile phone 102 ₃ which is a _third embodiment of the mobile phone 102. Substantially upper half side of the surface of the shield case 4A in FIG. 9 (A), the Yes and wave absorber 30 ₃ is a third embodiment of the radio wave absorber 30 is attached, in close contact.

The radio wave absorber 30 ₃ has a trapezoidal or substantially trapezoidal first radio wave absorber 31 ₃ and a triangular or substantially triangular second radio wave absorber 32 _3. the second wave absorber 31 _3, 32 ₃ are arranged side by side. The wave absorber 30 ₃ has a rectangular or substantially rectangular shape. The first radio wave absorber 31 ₃ contains a first magnetic loss material. The second wave absorber 32 ₃ contains a second magnetic loss material.

[0072] The first wave absorber 31 _3, of the approximately upper half side of the shield case 4A, is disposed in the center portion and the left portion is greater the lower than the upper in the figure. In this way, the first radio wave absorption is provided between the housing 10 and the first maximum area of the shield case 4A where the surface current is maximum or substantially maximum when transmitting the wireless signal of the first frequency f1. it can be arranged body 31 _3.

[0073] The second wave absorbers 32 _1, of the approximately upper half side of the shield case 4A, is disposed on the upper right side portion. In this manner, between the case 10 and the second maximum area of the shield case 4A where the surface current is maximum or substantially maximum when transmitting the wireless signal of the second frequency f2.
It can be arranged a second wave absorber 32 _3.

[0074] In the portable telephone 102 ₃ in FIG. 9 (A), it is possible to absorb electromagnetic energy to effectively wave absorber 31 _3, 32 ₃ for radio signals of the first and second frequencies f1, f2, It is possible to increase the amount of SAR reduction.

FIG. 9B shows a mobile phone 102 ₄ which is a _fourth embodiment of the mobile phone 102. A fourth part of the radio wave absorber 30 is provided at a center part and a right part of a substantially upper half side of the surface of the shield case 4A in FIG.
Yes electric wave absorber 30 ₄ in the form of embodiment of the mounting, in close contact.

[0076] In the radio wave absorber 30 _4, has a first wave absorber 31 ₄ of triangular or shape substantially triangular, and a second radio wave absorber 32 ₄ of triangular or shape substantially triangular, the first and the second wave absorber 31 _4, 32 ₄ are arranged side by side. The wave absorber 30 ₄ has a trapezoidal or substantially trapezoidal. The first wave absorber 31 ₄ contains a first magnetic loss material. The second wave absorber 32 ₄ contains a second magnetic loss material.

[0077] The first wave absorber 31 _4, of the approximately upper half side of the shield case 4A, is arranged in the center portion. In this way, the first radio wave absorption is provided between the housing 10 and the first maximum area of the shield case 4A where the surface current is maximum or substantially maximum when transmitting the wireless signal of the first frequency f1. it can be arranged body 31 _4. Also,
In the first electromagnetic wave absorber 31 ₄ , the thickness of the portion 31A that is in close contact with the first maximum region is larger than the thickness of the portion 31C that is in close contact with the peripheral region of the first maximum region.

[0078] The second wave absorber 32 _4, of the approximately upper half side of the shield case 4A, is disposed on the upper right side portion. In this manner, between the case 10 and the second maximum area of the shield case 4A where the surface current is maximum or substantially maximum when transmitting the wireless signal of the second frequency f2.
Second radio wave absorber 32 ₄ are disposed. Also, the second
Wave absorber 32 _4, the thickness of the portion 32A in close contact with the second largest area is greater than the thickness of the portion 32C in close contact with the peripheral region of the second maximum area.

[0079] In the portable telephone 102 ₄ in FIG. 9 (B), the can be absorbed electromagnetic energy effectively wave absorber 31 _4, 32 ₄ for radio signals of the first and second frequencies f1, f2, It is possible to increase the amount of SAR reduction. In particular, by increasing the thickness of the portions 31A and 32A, the SAR reduction amount can be further increased.

The radio wave absorbers 30, 30 ₁ to 30
₄ is, for example, a rectangular parallelepiped or a substantially rectangular parallelepiped. As an example, the vertical and horizontal dimensions of the rectangular parallelepiped may be about 1 cm to about 4 cm (or about 2 cm to about 3 cm), and the thickness is about 1 mm to
It may be about 4 mm (or about 2 mm to about 3 mm).

The above embodiment is an exemplification of the present invention, and the present invention is not limited to the above embodiment. For example,
In the mobile phone 102 of FIG. 3, the radio wave absorber 30 may be attached to the surface of the shield case 4A with an insulating fixture or a screw.

[0082]

As described above, in the portable telephone according to the present invention, the first and second radio wave absorbers are based on the surface current of the shield case corresponding to the radio signals of the first and second frequencies. , It is possible to increase the amount of SAR reduction for the radio signals of the first and second frequencies. As described above, according to the present invention, it is possible to provide a mobile phone capable of reducing electromagnetic energy radiated from the inside of the mobile phone using a plurality of frequencies of radio signals to the side of the human head.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram illustrating a mobile phone.

FIG. 2 is a schematic explanatory view showing a mobile phone in which a radio wave absorber is attached to the mobile phone of FIG.

FIG. 3 is a schematic configuration diagram showing an embodiment of a mobile phone according to the present invention.

FIG. 4 is a schematic block diagram of the mobile phone shown in FIG. 3;

FIG. 5 is a characteristic diagram of the first and second magnetic loss materials.

FIG. 6 is a schematic distribution diagram illustrating the magnitude of a radio wave radiated from the surface of the shield case, wherein the frequency of a transmitted radio signal is about 900 MHz.

FIG. 7 is a schematic distribution diagram illustrating the magnitude of radio waves radiated from the surface of the shield case, wherein the frequency of a transmitted radio signal is about 1.8 GHz.

8 is a first explanatory diagram illustrating a state where a radio wave absorber is attached to a shield case in the mobile phone of FIG. 3;

9 is a second explanatory view illustrating a state where a radio wave absorber is attached to a shield case in the mobile phone of FIG. 3;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Antenna, 2 ... Feeder part, 2A ... Switching circuit (S
W) 3, ... printed circuit board, 4, 4A ... shield case,
5 Printed circuit board, 5A, 5B parts, 6 transmitter (MIC), 6H hole (transmitter), 7 keypad (P
AD), 8: liquid crystal display (LCD), 8W: window, 9: receiver, 9H: hole (earpiece), 10: housing, 11, 30,
30 ₁ to 30 ₄ ... radio wave absorber, 12, 21 ... adhesive, 3
1,31 _{1 to} 31 ₄ ... first radio wave absorber, 32,32 ₁
~ 32 ₄ ... second radio wave absorber, 49 ... head side area, 50
... Control circuit (CNT), 56 ... Transmission circuit (TRS), 5
9 receiving circuit (RCV), 90 user, 91 head (human head), 100 to 102 mobile phone, M1 characteristic curve of first magnetic loss material, M2 second magnetic loss material , S1: first audio signal, S2: second audio signal, S11: first wireless signal, S12: second wireless signal.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) // H05K 9/00 H05K 9/00 C 5K067 H04B 7/26 V (72) Inventor Bun Iwashita Shinagawa, Tokyo 4-11-1, Kita-Shinagawa-ku, Tokyo Career Development International Co., Ltd. (72) Yoshiki Kanayama Inventor Yoshitaka Kanayama 6-7-35 Kita-Shinagawa, Shinagawa-ku, Tokyo Inside Sony Corporation (72) Inventor Hiroki Ito 6-35 Kita-Shinagawa, Shinagawa-ku, Tokyo F-term (reference) within Sony Corporation LL06 QQ00 QQ05 RR01 5K067 AA35 BB04 EE02 EE32 KK01 KK17

Claims (9)

[Claims] An antenna, a transmitter for generating a first audio signal corresponding to an input sound, and a first radio signal modulated by modulating the first audio signal from the transmitter. A transmission circuit that generates and transmits the first wireless signal via the antenna; and a second wireless signal that is a second wireless signal input to the antenna, wherein a second audio signal is modulated. A receiving circuit that demodulates the signal to generate the second audio signal; a receiver that outputs a sound corresponding to the second audio signal from the receiving circuit; and a printed circuit on which the receiving circuit and the transmitting circuit are mounted. A board, a shield case surrounding the printed circuit board so as to suppress electromagnetic interference between the printed circuit board and the antenna, the printed circuit board, a first radio wave absorber, a second radio wave absorber, and the shield. Case, the transmitter and A mobile phone having an insulative housing for storing the handset and the receiver, wherein the first wireless signal has a first frequency wireless signal and a second frequency wireless signal, A transmission circuit for selectively generating a radio signal of the first or second frequency, wherein the first and second radio wave absorbers are between the shield case and the housing, and are used during a call. The first radio wave absorber is disposed in a region located on the side of the head of the human body, and the first radio wave absorber has a maximum or substantially maximum imaginary part of magnetic loss or complex magnetic permeability at or near the first frequency. The shield case includes a magnetic loss material, and is disposed between the first maximum region where the surface current is maximum or substantially maximum in the shield case when transmitting the wireless signal of the first frequency and the housing. And the second radio wave absorber is the second radio wave absorber. A magnetic loss or an imaginary part of a complex magnetic permeability at or near the frequency contains a second magnetic loss material having a maximum or substantially the maximum, and a surface of the shield case when transmitting a radio signal of the second frequency. A mobile phone disposed between the housing and a second maximum area where a current is maximum or substantially maximum. 2. The surface of the shield case has conductivity, and the first radio wave absorber is attached to the first maximum area and its peripheral area of the surface of the shield case. The mobile phone according to claim 1, wherein the second radio wave absorber is attached to the second maximum area and a peripheral area thereof on the surface of the shield case. 3. The first radio wave absorber is in close contact with the surface of the shield case, and the thickness of a portion in close contact with the first maximum region is a peripheral region of the first maximum region. 3. The mobile phone according to claim 2, wherein the thickness of the mobile phone is larger than a thickness of a portion closely contacting the mobile phone. 4. The second radio wave absorber is in close contact with the surface of the shield case, and the thickness of a portion in close contact with the second maximum region is a peripheral region of the second maximum region. 3. The mobile phone according to claim 2, wherein the thickness of the mobile phone is larger than a thickness of a portion closely contacting the mobile phone. 5. The first radio wave absorber is a molded product obtained by mixing a powder of the first magnetic loss material with a synthetic resin, and the second radio wave absorber is a second radio wave absorber. The mobile phone according to claim 1, wherein the mobile phone is a molded product obtained by mixing a powder of the magnetic loss material and a synthetic resin. 6. One of the first and second frequencies is about 800 MHz or about 900 MHz, and the other of the first and second frequencies is about 1.8 MHz.
The mobile phone of claim 1, wherein the frequency is at or about 2 GHz. 7. A switching circuit interposed between the transmitting circuit and the receiving circuit and the antenna, wherein the switching circuit is mounted on the printed circuit board, and the first circuit from the transmitting circuit is provided. The mobile phone according to claim 1, wherein the wireless signal is supplied to the antenna, and the second wireless signal from the antenna is supplied to the receiving circuit. 8. The shield case includes a case made of an insulating material, and a conductive layer formed on a surface of the case. The conductive layer is connected to a ground layer of the printed circuit board. The mobile phone according to claim 1. 9. The mobile phone according to claim 1, wherein said shield case is made of a conductive material and is connected to a ground layer of said printed circuit board.