Kjell Hansson Mild

Electrical appliances,mobile phones and

cordless phones

Kjell Hansson Mild

Dept. of Radiation SciencesRadiation Physics

Umeå University Umeå, Sweden

kjell.hansson.mild@radfys.umu.se

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B (μ

T)

0 10 20 30 40 50-10-20-30-40-50Avstånd från mitten (m)

Magnetic flux density Phase current 500 A, 1,8 m above ground

4,61

m

12 m

RS

TR S

4,61

m

12 m

5,5

m

7,6 m

7 m 7 m

12 m

Kjell Hansson Mild

Horisontals2

I x 0,35 d2

B(μT)

Triangulars2

I x 0,25 d2

B(μT)

s3

I x 0,35 d2

B(μT)Splitphases

I phase currentd phase distances distance to middle of line

Magnetic field from power lines

Kjell Hansson Mild

Where can we find

magnetic fields?

Cable I

I

Electric equipment

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Kjell Hansson Mild

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0.9

1.0

0 1 2 3 4 5 6

Avstånd (m)

Fa

kto

r

Enkelledare

Punktkälla

Distans dependence

Kjell Hansson Mild

Transients

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Kjell Hansson Mild

450 MHz

900 or 1800 MHz

GSM

Output power depends on distanceto base station (0,0004- 0,25 W)

Today

NMT

DTX

Power about 1 W

Tomorrow:

UMTS

1900 MHz

Power < 0,02- 0,25 W

Power regulation 1500/s

Liknande DTX

GSM = Global system for MobileCommunication

UMTS = Universal Mobile Telecommunication System, also called 3G.

Kjell Hansson Mild

GSM 900890-914 MHz uplink, 935-959 MHz downlink

Pulsed output power max 2W, 217 Hz/2 Hz

Down regulation in steps to 3 mW

Duty cycle 1/8 gives max mean power 0.25 W

and low mean 0.4 mW

DCS 18001710-1785 MHz uplink, 1805-1880 MHz downlink

Peak pulse power max 1 W, low 2 mW

Max mean power 0.125 W, low mean 0.25 mW

With DTX system further reduction

Kjell Hansson Mild

DECT1880-1900 MHz up- and downlink

peak power 250 mW, 100 Hz rep. rate

Duty cycle 1/24, mean power about 10 mW

UMTS1920-1980 MHz uplink, 2120-2170 MHz downlink

CW, Max power 0.25 W, power regulation

1500 times/s, DTX

Kjell Hansson Mild

TETRA frequency

• 380 MHz to 400MHz

– 10 MHz duplex spacing

• 5 MHz block of spectrum in uplink and

downlink directions.

Kjell Hansson Mild

Modulation

TETRA

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TETRA 4 timeslots

14mS

56mS i.e 17 bursts per second

HANDSETS

BASE STATION

Continuous tone

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M2

M3

M4

1.2

1.0

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M1

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Kjell Hansson Mild

Gert Anger, Sthm: SAR and transmitted

power for 21 mobile phonesThe Bioelectromagnetics Society 25th Annual Meeting

Wailea, Maui, Hawaii, June 22-27, 2003

Highest SAR values: from 0.49 to 1.7 W/kg.

Emitted power (TCP) 900: from 0.19 to 0.49 W

1800 MHz: 0.056 to 0.26 W

Ratio SAR/TCP for

900 MHz phones 0.24 - 2.9 W/kg/W

1800 MHz: 0.76 - 5.4 W/kg/W

Kjell Hansson Mild

SAR-and TCP-värden;From TCO

Kjell Hansson Mild

Output Power Distribution of 3G WCDMA Mobile Phonesbased on Network Measurements

T Persson, C Törnevik, LE Larsson, BEMS 2006

In the WCDMA system the output power of connected phones ranges

from 250 mW down to below 0.01 μW (24 dBm to below –50 dBm) and is

adjusted 1500 times per second.

Kjell Hansson Mild

GSM mobile phone output power distribution by network

analysis of all calls in some urban, rural and in-office

networks, complemented by test phone measurements

T. Persson, C. Törnevik, L-E. Larsson, J Lovén, BEMS 2002

Kjell Hansson Mild

BluetoothBluetooth uses the ISM (Industrial Scientific

Medical) 2.4 GHz

Output power from 100 mW to 1 mW.

For use with mobile phone it is 1 mW and about

10 m reach.

Kjell Hansson Mild

IP telephony

Connection through phone or Internet; Cable or

wireless: 2.4 GHz,

Output power from base or phone:

100, 50, 20, 5, or 1 mW, has to be set,

not automatic

Cisco 7920 (usual one) SAR 0.75 W/kg at100 mW!

Cable: Need external power, can give very high

E-field ner the phone, hundreds V/m band 1,

tens of V/m band 2.

Törnevik (2000) Radiofreqency exposure from mobile communication

devices. Report T/F-00:033 Ericsson Research, Stockholm.

MP

Wireless

phones

Modem

Multimedia

terminal

PC card

Type System Freq. Band Max Max. Exp.

MHz Mean output power 10 g SAR W/kg

Kjell Hansson Mild

2120MHz

210MHz

50MHz

W/Kg

Results: surface SAR distribution

120 MHz 210 MHz 500 MHz 1 GHz