GB2513091A - Radiation shield - Google Patents

Abstract

The present invention comprises a radiation shield for use with an electronic device, such as a mobile telephone, to reduce the level of undesirable radiation transferred from the device to the surroundings. The radiation shield comprises a housing which can be fitted to an electrical device, said housing comprises a radiation disruption means and a means of connecting the radiation disruption means to the electrical device. In preferred embodiments, the shield is formed from iron powder in a polyethylene matrix and can take the form of a sheet which can be adhered to the device via a self-adhesive film.

Description

Radiation Shield The present invention relates to a radiation shield and more particularly to a radiation shield for use in an electronic device, such as a mobile telephone, to reduce S the level of undesirable radiation transferred from the device to the surroundings.

All mobile telephones emit electromagnetic radiation, using radio frequency (RF) waves to make and receive calls. Electromagnetic iadiation emitted by mobile telephones can cause a heating effect. This heating effect is not typically considered harmful since it is normally insufficient to cause any type of long-term damage to tissue.

However, given the close proximity of the mobile telephone to a user's head and the duration of time that can be spent on. th.e telephone, recent publicity has 0') focused on whether such electromagnetic radiation is can cause a degree of harm.

As such, there is a public demand for a device that can reduce the level of 0 15 undesirable radiation transferred from an electronic device to the surroundings. Also, given the popularity and variety of hand-held electronic devices, such as mobile telephones, that are available, there is also a need for the device to be discreet and user-friendly.

The present invention has been anived at with the aforementioned issues in mind.

Thus, according to a first aspect of the present invention, there is provided a radiation shield for use with an electrical device comprising a housing containing a radiation emitting element, the radiation shield comprising a radiation disruption means and a means of connecting the radiation disruption means to the electrical device.

The electrical device is typically a mobile telephone, hut may also take the foirn of a cordless landline telephone, portable computer such as a laptop or tablet, MP3 player, and the like. Similarly, the radiation shield may also be used in any household appliance containing a radiation emitting element. Hereinafter, the electrical device is reFerred to as a mobile telephone for convenience and illustrative purposes only.

The radiation shield of the present invention provides a means of limiting the extent of electromagnetic radiation emission from a mobile telephone.

The radiation shield may take the form of a plate. The plate may have dimensions that enable it to be located within a mobile telephone housing.

The plate may be retro-fitted within existing mobile telephones.

In some embodiments, the plate substantially corresponds to the size of thc 0') battery present in the mobile telephone. Since the size and shape of mobile telephones vary depending on the manufacturer and model, the radiation shield of the 0 15 present invention may also vary in size accordingly. In alternative embodiments, the radiation shield may be smaller or larger than the battery of the mobile telephone. In further alternative embodiments, the radiation shield may correspond to the size of the mobile telephone.

Preferably, the radiation shield is smaller than the battery of the mobilc telephone. The devicc can be discreetly fitted to any mobile telephone. This is beneficial given the vast array of different sizes and shapes of mobile telephone, together with the varying ease designs and the like.

The means of connecting the radiation disruption means to the mobile telephone enables the radiation disruption means to be secured within or on the mobile telephone. Any suitable means of connecting the radiation disruption means to the mobile telephone are envisaged.

-Typically, the connecting means comprises an adhesive.

Suitable adhesives would be known to a person skilled in the art. The S adhesive may comprise glue or a self-adhesive film. Preferably, the adhesive comprises an adhesive film. The adhesive film may have a non-sticky surface which is partially or completely covered by the radiation disruption means and an opposing sticky surface. The sticky surface may be partially or completely covered by a removable sheet. The removable sheet may be a paper material. Thus, in use, the removable sheet can be peeled off, allowing the radiation shield to be attached to a surface of the mobile telephone. The radiation disruption means may alternatively or additionally be located on the sticky surface.

0') The radiation disruption means may partially or completely cover the surface of the connecting means.

0 15 In some embodiments, the radiation. disruption means is in the form of a layer affixed to a layer of adhesive. In alternative embodiments, the radiation disruption means may be mixed with the adhesive.

The radiation disruption means is suitable for absorbing, blocking and/or reflecting electromagnetic radiation emitted by a mobile telephone, such. as RF radiation.

The radiation disruption means may comprise iron.

Preferably, the radiation disruption means comprises an iron powder.

In some embodiments, the iron powder may be sprayed onto the connecting means. Alternatively, the iron powder may be roiled onto the connecting means.

The radiation shield may comprise a layered structure. The radiation shield may comprisc a support layer sandwiched between the connecting means and the radiation disruption means. The support layer may therefore comprise first and second surfaces, wherein the means of connecting the radiation disruption means to the mobile telephone is located on a first surface and the radiation disruption means is located on a second surFace. Beneficially, the support layer provides increased structural integrity to the device.

The radiation disruption means may partially or completely cover the sw-face of the support layer.

The radiation disruption means may be sprayed onto a surface of the adhesive film ancb'or support layer. Alternatively, the radiation disruption means may eomprse a solid film that can be adhered onto a surface of the adhesive film and/or support 0') layer.

The support layer may comprise any material on which the adhesive and 0 15 radiation disruption means may be connected. In some embodiments, the support layer may comprise a plastics material, a resin, a rubber or a fabric. Preferably, the support layer comprises a polyethylene material.

The radiation shield may comprise a protecting layer that partially or completely covers the radiation disruption means. The protecting layer may comprise the same material as tile support layer.

The radiation shield may be located on, adjacent to or in close proximity to, the radiation emitting element of the electrical device.

According to a second aspect of the present invention, there is provided tile use of a radiation shield as described herein for disrupting radiation emitted from an electronic device.

The invention will now be described further by way of example with reference the following drawings which are intended to be illustradve only and in no way limiting upon the scope of the invention: Figure 1: a diagrammatic representation of a radiation shield according to the present invention; Figure 2: a diagrammatic representation of another embodiment of a radiation shield according to the present invention; Figure 3: a representation of a radiation shield according to the present invention incorporated in a mobile telephone.

Referring to Figure 1, there is shown a radiation shield 1 conhpnsing a CT) radiation disruption means 2 combined with an adhesive 3.

CO The adhesive 3 is in the form of a film comprising a non-sticky surface 4 0 15 covered by the radiation disruption means 2 and a sticky surfaceS. The sticky surface is covered with a removable paper protection layer 6.

When the radiation shield I is to he fitted to a radiation emitting electrical device, the protection layer 6 is simply peeled off to reveal the sticky surface of the adhesive film 3. The sticky surface of the adhesive film 3 is then stuck to a surface in or of the electrical device, such as a mobile telephone to which the radiation shield 1 is to be fitted.

Referring to Figure 2, there is shown an alternative embodiment of the radiation shield I compnsing a polyethylene support layer 7.

The radiation shield I can be attached to any device comprising a housing containing a radiation emitting element, such as for example, an antenna.

Referring to Figure 3, there is shown a radiation shield 1 located within a mohilc telephone 8, comprising a housing 9 (of -which the back cover section is not shown) and an antenna 1 0. As can be seen, the radiation shield I is located across a part of the battery 11 and an internAl body portion 12 of the mobile telephone 8, in close proximity to the antenna 10.

In use, the radiation disruption means 2 limits the extent of electromagnetic radiation emission from a mobile telephone 8. As shown in Figure 3, the radiation shield I can be adhered to a section of the mobile telephone casing 12 or the battery 11.

The results of testing of the radiation shield 1 are shown in Table I with details of the test method included in the pages below. The test was conducted in the GSM 900MHz frequency band, at a temperature of from 21 to 23.8°C and at a 0') humidity of from 54 to 60%. The results of the test are shown in Table 1: 0 _____ ___ _____ Phantom Device Test Radiation Channel Results of Specific O Configurations Positions Shield 1 Absorption Rate (SAR) (W/Kg) log Ig Right Side of i-lead Cheek/Touch -38 0.920 1.321 Right Side of Head Cheek/Touch Yes 38 0.026 0.039 SAR value with Radiation Shield I deviation from the 97.17% 97.04% reference value (i.e. the SAR value tested without the radiation shield 1) Table 1: Test Results It can be concluded from the test results that in GSM 900MHz frequency band, the Specific Absoprtion Rate (SAR) can reduce by 97.17% after using the radiation shield 1 of the present invention in the lOg test and by 97.04% after using the radiation shield I of the present invention in the ig test.

It is of course to be understood that the present invention is noIL intended to be restricled to the foregoing examples which are described by way of example only. a) aD a

DIRECTORY

1. TESTING LABORATORY 4 1.1. Identification of the Responsible Testing Laboratory 4 1.2. Identification of the Responsible Testing Location 4 1.3. Accreditation Certificate 4 1.4. List of Test Equipments 4 2. TECHNICAL INFORMATION 5 2.1. Identification of Applicant 5 2.2. Identification of Manufacturer 5 2.3. Equipment Under Test (EUT) 5 2.3.1. Photographs of the EUT 5 2.4. Applied Reference Documents 5 2.5. Test Environment/Collditions 6 3. SPECIFiC ABSORPTION RATE (SAR) 7

" 3.1. Introduction 7

Cl) 3.2. SAR Definition 7 4. SALR MEASUREMENT SETUP 8 Co O 4 The Measurement System 8 4.2. Probe 8 4.3. Phantom 10 4.4. Device Holder 10 5. TISSUE SIMULATING LIQUIDS 11 6. UNCERTAINTY ASSESSMENT 12 6.1. UNCERTAINTY EVALUATION FOR HANDSET SAR TEST 12 6.2. UNCERTAINTY FOR SYSTEM PERFORMANCE CHECK 13 7. SAR MEASUREMENT EVALUATION 15 7.1. System Setup 15 7.2. Validation Results 15 S. OPERATIONAL CONDITIONS DUPING TEST 16 8.1. Informations on the testing 16 8.2. Measurement procedure 16 8.3. Description of interpolation/extrapolation scheme 17 9. TEST RESULTS LIST.18 ANNEX A PHOTOGRAPHS OF THE EUT 19 ANNEX B GRAPH TEST RESULTS 21 Change History Issue Date Reason for change 1.0 Nov.12, 2012 First edition a) aD 1.

Q) 1.4. ListofTestEquipments 0,..-. .:.;,. .CiJ' . No' Iñstñiment i1'ype. aj Date tqal Due Dell (Pentium IV 2.4GHz, 1 Pc SN:X10-23533) (na) (n.a) Network Rohde&Schwarz (cMTJ200, 2., 2012-9-26 lyear Rmulator SN: 105894) _____________ _________ 3 Voltmeter Keithley (2000, SN:1000572) 2012-9-24 lyear Rohde&Schwarz (SMTJ 03, 4 Synthetizer SN:101868) -2012-9-24 lyear Amplifier Nucludes(ALB2I6, SN:10800) 2012-9-24 lyear 6 Power Meter Rohde&Schwarz (NRVD, SN:101066) 20 12-9-24 lyear 7 Probe Satimo (SN:SN$708_EPSO) 2012-9-24 1.year 8 Phantom Satimo (SN:SN_36J)8_SAM62) 20 12-9.24 lyear 9 Liquid Satimo (Last calibration:201 1-12-13) NA NA 835MHz Satimo (SN 36/08 DIPC 99) 2012-10-05 lyear 2. Technical information Note; the following data is based on the information by the applicant.

2.3.1. Photographs of the EUT Please see for photographs of the BUT. a)

2.4. Applied Reference Documents Co * O reference,,*,.,,. . No IdentIty _______ Dootmient Title _____________±_________________________ 1 EN 50360: 2001 Product standard for the measurement of Specific Absorption Rate related to human exposure to electromagnetic fields from __________________ OSM Mobile phones. - 2 EN 62209-1:2006 Human exposure to radio frequency fields from hand-held and body-mounted wireless communication devices -Human models, instrumentation, and procedures -Part 1: Procedure to determine the specific absorption rate (SAR) for hand-held devices used in close proximity to the ear (frequency range of 300 MHz to 3 _____ ______ 0Hz) ________ ____________ 3 EN 62311:2008 Assessment of electronic and electrical equipment related to human exposure restrictions for electromagnetic fields (0 Hz - 300 0Hz) ________________________ ________________ 2.5. Test Environment/Conditions Normal Temperature (NT): 20... 25 °C Relative Humidity: 30... 75 % Air Pressure: 980... 1020 hPa Test frequency: GSM 900MHz Operation mode: Call established Power Level: OSM 900 MHz Maximum output power(level 5) During SAR test, EUT is in Traffic Mode (Channel Allocated) at Normal Voltage Condition. A communication link is set up with a System Simulator (SS) by air link, and a call is established.

The Absolute Radio Frequency Channel Number (ARFCN) is allocated to 975, 38 and 124 respectively in the case of CTLSM 900 Mhz. The EUT is commanded to operate at maximum transmitting power.

The EUT shall use its internal trainsmitier, The antenna(s), battery and accessories shall be those specified by the manufacturer. The HIT battery must he fully charged and checked periodically during the test to ascertain uniform power output. if a wireless link is used, the antenna connected to the output of the base station simulator shall be placed at least 50 cm away from the handset.

The signal transmitted by the simulator to the antenna feeding point shall be lower than the output power level of the handset by at least 35 dB. a) aD

3. Specific Absorption Rate (SAR)

3.1. Introduction

SAR is related to the rate at which energy is absorbed per unit mass in an object exposed to a radio field. The SAR distribution in a biological body is complicated and is usually carried out by experimental techniques or numerical modeling. The standard recommends limits for two tiers of groups, occupational/controlled and general popuiation/uiiconfrolled, based on a person's awareness and ability to exercise control over his or her exposure. In general, occupational/controlled exposure limits are higher than the limits for general populationluncontrolled.

3.2. SAIR Definition The SAR definition is the time derivative (rate) of the incremental energy (dW) absorbed by (dissipated in) an incremental mass (dm) contained in a volume element (dv) of a given density.

p). The equation description is as below:

SM= if::) 1fr1 SAR is expressed in units of Wafts per kilogram (W/kg) SAR measurement can be either related to the temperature elevation in tissue by aD 0 or SAJ..t C of where C is the specific head capacity, 5 T is the temperature rise and 8 t the exposure duration, or related to the electrical field in the tissue by if I SAR= ri p * where a is the conductivity of the tissue, is the mass density of the tissue and B is the rms

electrical field strength.

However for evniuating SAR of low power transmitter, electrical field measurement is typically applied.

4. SAR Measurement Setup 4.1. The Measurement System Comosar is a system that is able to determine the SAR distribution inside a phantom of human being according to different standards. The Comosar system consists of the following items: -Main computer to control all the system -6 axis robot -Data acquisition system

-Miniature B-field probe

-Phone holder -Head simulating tissue a) aD The BUT under test operating at the maximum power level is placed in the phone holder, under the phantom, which is filled with head simulating liquid. The B-Field probe measures the electric field inside the phantom. The OpenSAR software computes the results to give a SAR value in a Ig or log mass.

4.2. Probe For the measurements the Specific Dosimetric B-Field Probe SN 37/08 EP8O with following

specifications is used

-Dynamic range: 0.01-100 W/lcg -Tip Diameter: 6.5 mm -Distance between probe tip and sensor center: 2,5mm -Distance bctween sensor center and the inner phantom surface: 4 mm (repeatability better than +1-imm) -Probe linearity: <0.25 dB -Axial Isotropy: <0.25 cIB -Spherical Isotropy: <0.25 dB -Calibration range: 835to 2500MHz for head & body simulating liquid.

Angle beiweeri probe axis (evaluation axis) and sui'ace normal linc:lcss than 300 Probe calibration is realized, in compliance with CENELEC EN 62209 and IEEE 1528 std, with CAL1SAR, Antennessa proprietary calibration system. The calibration is performed with the EN 622091 amicxc technique using reference guide at the five frequencies. a) aD

BAR = 4 (.E,.-.a r2 c Where Pfw = Forward Power Pbw = Backward Power a and b = Waveguide dimensions 1 = Skin depth Keith icy configuration: Rate = Medium; Filter 0N; RDGS1 0; FILTER TYPE MOVING AVERAGE; RANGE AUTO After each calibration, a SAR measurement is performed on a validation dipole and compared with a NPL calibrated probe, to verify it.

The calibration factors, CF(N), for the 3 sensors corresponding to dipole 1, dipole 2 and dipole 3 are: CF(N)SAR(N)/Vlin(N) N=1,2,3) The linearised output voltage Vlin(N) is obtained from the displayed output voltage V(N) using Vlin(N)\IN)t@+V(N)IDCP(N)) (N=1,2.3) where DCP is the diode compression point in mV.

4.3. Phantom For the measurements the Specific Anthropomorphic Mannequin (SAM) defined by the IEEE SCC-34/SC2 group is used. The phantom is a polyurethane shell integrated in a wooden table. The thickness of die phantom amounts Ic 2mm +1-0.2mm. It enables the dosimetric evaluation of left and right phone usage and includes an additional flat phantom part for the simplified performance check.

The phantom set-up includes a cover, which prevents the evaporation of the liquid.

4.4. Device Holder The positioning system allows obtaining cheek arid tilting position with a very good accuracy. In 0') compliance with CENELEC, the tilt angle uncertainty is lower than 10. aD

Device holder SystemMatenal Penrntbvtty Loss Tangent Delrin 3.7 0.005 ________ 5. Tissue Simulating Liquids Simulating liquid used for testing at frequencies of 835MHz and 1800MHz, which are mainly made of sugat; salt and water. Approximately 2olitres are needed for an upright head compared lo about 25 liter for a horizontal bath phantom. The liquid height from the ear reference point (ERP) of the phantom to the liquid top surface is (hea.d SAR)or from the flat phantom to the liquid top surface (body SAR) is 15cm.

Following are the recipes for one liter of head tissue simulating liquid for frequency band 835 MHz arid 1800MHz. ________________ ________________ Ingredients Frequency Band (% by weight) 835MHz Tissue Type Head _____ Water _____ 41.45 Salt(NaCl) 1.45 * Sugar 36.0 HEC 1.0 Bactericide ______ 0.1 Triton 0.0 * DOBE 0.0 0') Acticide SPX 0.0 ° Dielectric Constant 42.45 CO Conductivity (S/ni) 0.91 O Recipes for Tissue Simulating Liquid The dielectric parameters of the liquids were verified prior to the SAR evaluation using an Agilent 85033E Dielectric Probe Kit and an Agilent Network Analyzer.

Table 1: Dielectric Performance of Head Tissue Simulating Liquid Teniperature:_23.O-23.8°C, humidity: 54--6O%. _______________ / Frequency Permittivity a Conductivity 6 (SIm) Targetvalue 835MHZ 41.5 0.90 Validation value 835 MHZ 41.675999 0.894409 (N ov.5) _________________ ___________________ _______ 6. Uncertainty Assessment The following table includes the uncertainty table of the IEEE 1528. The values are determined by Antennessa.

6.1. UNCERTAiNTY EVALUATION FOR HANDSET SAR TEST a b c d f(d,k) f g h 1k ctf'e c*gle Uncertainty Component Sec. Tel Prob. Div. Ci (Ig) Ci ig UI lOg IJi V (4--% Dist. (log) (+.%) (+-%) ____________ ___) ___ ____ ___ __ __ Measurement System _____ ______ ______ ______ ________ _______ _______ Probe calibration Eli 7.0 N 1 1 1 7.00 7.00 Axial Isotropy E.2.2 2.5 R 0.7 0.7 1.01 1.01 Hemispherical Isotropy E,2.2 4.0 R -J 0.7 0.7 162 1.62 Boundary effect E.2.3 1.0 R 1 1 0.58 0.58 Linearit' E.2.4 5.0 R I 1 2.89 2.89 .... System detection limits E.2.5 1.0 R 1 1 0.58 0.58 Readout Electronics E.2.6 0.02 N 1 1 1 0.02 0.02 O Reponse Time E.2.7 3.0 R..5 1 1 1.73 1.73 JntegrationTinie E.2.8 2.0 R I 1 1.15 1.15 O RF ambient Conditions E.6.l 3.0 R J3' 1 1 1.73 1.73 Probe positioner Mechanical E.6.2 2.0 R J 1 1 1.1 5 1.15 Tolerance _____________ _________ ________ ______ ___________ _____ __________ Probepositieningwithrespect E,6.3 0.05 R 1 1 0.03 0.03 to Phantom Shell _____ _______ _______ Extrapolation, interpolation E.5.2 5.0 R 1 1 2.89 2.89 and integration Algoritms for Max. SAR Evaluation _______ ______ ______ ________ _______ _______ _______ _______ - Test sample Related _________ _______ _______ ___________ _________ _________ _________ _________ -Test samplepositioning E.4.2.1 0.03 N I I 1 0.03 0.03 N Device Molder Uncertainty E.4.1.l 5.00 N 1 1 1 5.00 5.00 OutputpowerPowerdrift-6.6.2 2.74 It.11 1 1 1.58 1.58 SAR drift measurement ____ ________ ____ ________ Phantom and Tissue Parameters _________ _______ ________ _______ _______ -Phantom Uncertainty (Shape E.3.1 0.05 R 1 1 0.03 0.03 and thickness tolerances) _____ _______ ______ __________ _______ _________ ________ ________ Liquid conductivity -deviation E,3.2 4.57 R 0,64 0.43 1.69 1,13 &om target value ______ ______J______ -_____ _______________ _______ -____ -Liquid conductivity -E.3.3 5.00 N 1 0.64 0.43 3.20 2.15 M measurement uncertainty _______ _______ ______ Liquid permittivity -deviation E.3.2 3.69 R 0.6 0.49 1.28 1.04 from target value Liquid pennittivity -E.3.3 10.00 N 1 0,6 0.49 6.01) 4.90 M measurement uncertainty ________ ______ _______ ______ ________ ________ ________ Combined Standard RSS 12.52 11.71 Uncertainty ______ _____ _______ ______ ______ ______ ______ Expanded Uncertainty Ic 25.05 23,42 (95% Confidence interval) ________ ______ _______ _________ ________ _____ ________ 6.2. UNCERTAINTY FOR SYSTEM PERFORMANCE CHECK a b cd ef(dc)f 8 bi _______ ____ ______ c*V/e c*g/e j Uncertainty Component Sec. Tol Prob. Div. Ci (ig) Ci 1g Ui lOg UI V (± % Dist. (log) (f-%) (÷-%) ______________________________________________________ _______________) ____________ _____________ _______________ _________ _____________ _______________ Measurerncnt System ______ _____ ____ _______ ____ ______ ______ ________ Probe calibration E.2.1 7.0 N 1 1 1 7.00 7.00 Axial Isotropy E.2.2 2.5 R 0.7 0.7 1.0! 1.01 O Hemispherical Isotropy E.2,2 4.0 R 0.7 0.7 1.62 1.62 Boundary effect E.2.3 1.0 R 1 1 0.58 0.58 O Linearity E.2.4 5.0 R Vi 1 1 2.89 2.89 System detection limits E.2.5 1.0 R Vi 1 1 0.58 0.58 Readout Electronics E.2.6 0.02 N 1 1 1 0.02 0.02 ReponseTime. E.2,7 3.0 R Ji 1 1 1.73 1.73 !ntegrationTimc E2.8 2.0 R Ji 1 1 1.15 1.15 RF ambient Conditions E,6.l 3.0 R Vi 1 1 1.73 1.73 Probe positioner Mechanical E,6.2 2.0 R Vi 1 1 1.15 1.1 5 Tolerance ______ _______ _______ __________ _________ _________ Probe positioning with respect E.6.3 0.05 R Vi 1 1 0.03 0.03 to Phantom Shell _______ ______ _______ _________ _____ ________ ________ Extrapolation, interpolation E.5.2 5.0 R Vi 1 1 2.89 2.89 and integration Algoritms for Max. SAR Evaluation ___-_____ _____ Dipole ________ ______ _____ _________ ________ ________ ________ Dipole axis to liquid Distance 8,E.4.2 1.00 N Vi 1 1 0.58 0.58 N !nputpowerandSARdrift 8,6.6,2 2.74 K Vi 1 1 1.58 1.58 measurement ________ _______ ______ _________ j _______ ________ _______ ________ Phantom and Tissue Parameters Phantom Uncertainty (Shape E.3.1 005 R I I 003 0.03 and thickness tolerances) Liquid conductivity -deviation E.3.2 4.57 P. Ji 0.64 0.43 L69 1.13 from target value Liquid conductivity -E.3.3 5.00 N 1 0.64 0.43 3.20 2.15 M measurement uncertainty Liquid permittivily -deviation E.3.2 3.69 R 0.6 0.49 1.28 1.04 from target value Liquid perinittivity -E.3.3 10.00 N 1 0,6 0.49 6,00 4.90 M measurement uncertainty Combined Standard RSS 11,50 10.61 Uncertainty ______ _____ _____....-...-.--________ ______ Expanded Uncertainty Ic 23.00 21.21 (95% Confidence interval) ______ ______ _________ ________________ _______ ________ a) aD 7. SAR Measurement Evaluation 7.1. System Setup Tn the simplified setup for system evaluation, the DUT is replaced by a calibrated dipole and the power source is replaced by a continuous wave which comes from a signal generator at frequency 835 MHz and 1900 MHz. The calibrated dipole must be placed beneath the fiat phantom section of the SAM twin phantom with the correct distance holder. The distance holder should touch the phantom surface with a light pressure at the reference marking and be oriented parallel to the long side of the phantom.

Equipments

-name Type and specification

Signal generator E4433B Directional coupler 45OMHz-3GHz Amplifier 3W 502(10-2500MHZ) ___ Reference dipole 835MHz:SN 36/08 RL!? 7.2. Validation Results O Comparing to the original SAR value provided by SATIMO, the validation data should be within its specification of I 0 %. _____________________________ O Frequency ______ 835MHz Target value (lOg) 6.2 MT/Kg 250 mWinputpower ______ 1.615 W/Kg L Test value (lOg) ____ 6.460 W/Kg Note: System checks the specific test data please sec page 26-27.

8. Operational Conditions During Test 8.1. Inlormations on the testing I'he mobile phone antenna and battery are those specified by the manufacturer. The battery is fiaHy charged before each measurement. The output power and frequency are controlled using a base station simulator. The mobile phone is set to transmit at its highest output peak power level.

The mobile phone is test in the "cheek" and "tilted" positions on the left and right sides of the phantom-The mobile phone is placed with the vertical centre line of the body of the mobile phone and the horizontal line crossing the centre of the earpiece in a plane parallel to the sagittal plane ofi the phantom. a) aD

Description of the "cheek" position:

The mobile phone is well placed in the reference plane and the earpiece is in contact with the ear.

Then the mobile phonc is moved until any point on the front side get in contact with the cheek of the phantom or until contact with the ear is lost.

Description of the "tilted" position:

The mobile phone is well placed in the "cheek" position as described above. Then the mobile phone is moved outward away from the month by an angle of 15 degrees or until contact with the ear lost.

Remark: Please refer to Appendix B for the test setup photos.

8.2. Measurement procedure The following steps are used for each test position -Establish a call with the maximum output power with a base station simulator. The connection between the mobile and the base station simulator is established via air interface -Measurement of die local E-field va]ue at a fixed location. This value serves as a reference value for calculating a possible power drift.

-Measurement of the SAR distribution with a grid of 8 to 1 6mm * 8 to 16 mm and a constant distance to the inner surface of the phantom. Since the sensors can not directly measure at the inner phantom surface, the values between the sensors and the inner phantom smface are extrapolated. With these values the area of the maximum SAR is calculated by an interpolation scheme.

-Around this point, a cube of 30 * 30 * 30 mm or 32 * 32 * 32mm is assessed by measuring 5 or 8 * 5 or 3*4 or 5 mm. With these data, the peak spatial-average SAR value can be calculated.

8.3. Description of interpolation/extrapolation scheme The local SAR inside the phantom is measured using small dipole sensing elements inside a probe body. The probe lip must not be in contact with the phantom surface in order to minimize measurements errors, but the highest local SAR will occur at the surface of the phantom.

An extrapolation is using to determinate this highest local SA.R values. The extrapolation is based on a fourth-order least-square polynomial fit of measured data. The local SAP. value is then extrapolated from the liquid surface with a 1mm step. a,

0 The measurements have to be performed over a limited time (due to the duration of the battery) so the step of measurement is high. It could vary between 5 and 3 mm. To obtain an accurate assessment o of the maximum SAR averaged over 10 grams and I gram requires a very fine resolution in the three dimensional scanned data array.

9. Test Resttt List (GSM 900viEiz I3Lmd) __________________ _____________ {Thnvperature21.028°C;]awtidi.ty:546O% Phantom Device1st Ridiation Channel SAR(W/K.g) Configurations Positions Prothotor _______ _________ _____ tOg Eg Rigi't Side Cheek/Thuch N/A 38 O92O I.321 Of Head _________ _____________ Right Side Cheek7otich Yes 38 0.026 0.039 SAR value with. Radiation Protector deviation from the 9.7. I 7% 97.04% reterc.nce value _______ Note: The reference VLtILTC in cans tile SAR value tested without Radialion Protector a) aD Annex A Photographs of the MiT I EUT Left Head Touch/Cheek Position a) 2 Test sample 3 Test sample paste on the celiplione a, O Liquid Lev& Photo aD Annex B Graph Test Results

BAND ___________ PARAMETERS

Measurement 1: Left Head with Cheek device position on Middle Channel in GSM mode (celiphone alone) Measurement 2: Left Head with Cheek device position on Middle Channel in C-SM mode (Radiation Protector pasted on celiphone) a) aD MEASUREMENT 1.

Type: Phone measurement (Complete) Area scan resolution: dr=8mrn,dy=8mm Zoom scan resolution: dx=8mm, dy=8mm, dz5mrn Date of measurement: 07/11/2012 Measurement duration: 7 minutes 31 seconds A. Experimental conditions.

Phantom File zinf3.txt Phantom Left head Device Position Cheek Band GSM900 Channels _____ Middle Signal GSM B. SJAR Measurement Results Middle Band SAR (Channel 38): ________________ ____ o Frequency (MIHz) 897.599976 Relative permittivity (real part) _______ 40.330002 Relative perrnittivity 19.2 19999 ° Conductivity (S/rn) --0.95843 7 Power drift (%) -0.990000 Ambient Temperature: 22.4°C Liquid Temperature: 22.8°C ConvF: 28.479, 25.214, 27.196 Crest factor: 1:8 Maximum location: X-31.OO, Y=-11.OO SAil lOg (WIKg) 0.920329 SXR1g (W/Kg) 1.321395 ZAxis Scan a) aD MEASUREMENT 2 Type: Phone measurement (Complete) Area scan resolution: dx=8mm,dy8mm Zoom scan resolution: dx8mm, dy8mm, dz=5rrnn Date of measurement: 07/11/2012 Measurement duration: 7 minutes 53 seconds A. Experimental conditions.

Phantom File sam_direct droit2 surf8mm.txt Phantom Left head Device Position Cheek Band GSM900 Channels Middle Signal GSM ____________ B. SAlt Measurement Results Middle Band SAP. (Channel 38): _____________________________ o Frequency (MHz) 897.599976 Relative permittivity (real part) 40.330002 Relative permittivity ______ 19.219999 ° Conductivity (S/rn) 0.95 8437 Power drift (%) -2.200000 Ambient Temperature: 22.4°C Liquid Temperatnre: 22.8°C ConvF: 28.479, 25.214, 27.196 Crest factor: 1:8 Maxhti urn location: X-31.OO Y=44A)O [1II1 __ iTI 721 III 11III1I1±JiTT1 11 11 ZAxis Scan a) aD System Performance Check Data(835MHz) Type: Phone measurement (Complete) Area scan resolution: dx=Snmi,dy=Smm Zoom scan resolution: dx8rnm, dy8rnm, dz5rnm Date of measurement: 07/11/2012 Measurement duration: 13 minutes 27 seconds A. Experimental conditions.

Phantom File surf sam. plan.txt Phantom Validation plane Device_Position _______________________________________ Band 835MHz ChanneJs _________________________________ Signal CW B. SAB Measurement Results r Band SAlt _____________________ Frequency (MHz) 835.000000 o Relative permittivity (real part) 40.490002 Relative permittivity 15.070000 Conductivity (S/m) 0.9839 18 0 Power drift (%) -0.050000 Ambient Temperature: 22.4°C Liquid Temperature: 2 1.5°C _____ ConvF: 28.47925.214,27.196 Crest factor: 1:1 Maximum location: X=5.O0, Y1.00 [ SAR lOg (WJKg) 1.614732 I SAIR1g (W/Kg) 2.478462 Z Axis Scan a). aD

Claims (20)

1. CLAIMS: 1. A radiation shield for use with an electrical device comprising a housing containing a radiation emitting element, the radiation shield comprising a radiation disruption means and a means of connecting the radiation disruption means to the electrical device.
2. 2. A radiation shield as claimed in claim 1, wherein the radiation disruption means comprises iron.
3. 3. A radiation shidd as claimed in claim 2, wherein the iron is in the form of a powder.
4. 4. A radiation shield as claimed in any preceding claim, wherein the electrical device is a mobile telephone, a cordless landline telephone, a portable computer, an MP3 player or a household appliance containing a radiation emitting dement.
5. 5. A radiation shield as claimed in any preceding claim, wherein the radiation shidd is in the form of a p'ate.
6. 6. A radiation shield as claimed in claim 3, wherein the plate has dimensions that enable it to be located within a mobile telephone housing.
7. 7. A radiation shield as claimed in claim 6, wherein the radiation shield is smaller than the battery of the mobile telephone.
8. 8. A radiation shield as claimed in any preceding claim, wherein the means of connecting the radiation disruption means to the electrical device comprises an adhesive.
9. 9. A radiation shield as claimed in claim 8, wherein the adhesive is a glue or a self-adhesive film.
10. 10. A radiation shield as daimed in claim 9. wherein the adhesive film has a non-sticky surface which is partially or completely covered by the radiation disruption means and an opposing sticky surface.
11. II. A radiation shield as claimed in claim 10, wherein the sticky surface is partially or completely covered by a removable sheet.
12. 12. A radiation shield as claimed in claim 11, wherein the removable sheet comprises a paper material.
13. 13. A radiation shield as claimed in any of claims 9 to 12, wherein the radiation disruption means is located on the sticky surface.
14. 14. A radiation shield as claimed in any preceding claim, wherein the radiation disruption means is operable to absorb electromagnetic radiation emitted by a mobile telephone.
15. 15. A radiation shield as claimed in any preceding claim, comprising a layered structure, wherein the radiation shield comprises a support layer sandwiched between the radiation disruption means and the means for connecting the radiation disruption means to the electrical device.
16. 16. A radiation shield as claimed in claim 15, wherein the support layer comprises first and second surfaces, wherein the means of connecting the radiation disruption means to the electrical device is located on a first surface and the radiation disruption means is located on a second surface.
17. 17. A radiation shield as claimed in claim 16, wherein the radiation disruption means partially or completely covers the surface of the support layer.
18. 18. A radiation shield as claimed in any one of claims 15 to 17, wherein the support layer comprises a plastics material, a resin, a rubber or a fabric.
19. 19. A radiation shield as dainied in claim 18. wherein the plastic material comprises a polyethylene material.
20. 20. Use of a radiation shield as claimed in any one of claims 1 to 19 for disrupting radiation emitted from an electronic device.