TY - JOUR

T1 - SAR calculations in an anatomically realistic model of the head for mobile communication transceivers at 900 MHz and 1.8 GHz

AU - Dimbylow, P. J.

AU - Mann, S. M.

PY - 1994

Y1 - 1994

N2 - A new mathematical model of the head has been constructed from a set of serial MRI slices from one subject. Finite-difference time-domain (FDTD) calculations of the specific energy absorption rate (SAR) have been performed on this model with a 2 mm resolution for a generic mobile communication transceiver represented by a quarter-wavelength monopole on a metal box. The antenna was mounted either at the centre or corner of the top face of the box. The frequencies considered were 900 MHz and 1.8 GHz. Three irradiation geometries were considered, a vertical handset in front of the eye and vertical and horizontal orientations at the side of the ear. The effect of a hand grasping the handset was considered. The head model was scaled to represent the head of an infant and a subset of calculations was performed to verify that the SAR deposited in the infant head did not exceed that in the adult. Results are also presented for a half-wavelength dipole. The maximum SAR values produced by the generic transceiver for the horizontal orientation at the side of the head which is the most typical position, averaged over 10 g of tissue at 900 MHz and 1.8 GHz, are 2.1 and 3.0 W kg-1 per W of radiated power. The corresponding values over 1 g of tissue are 2.3 and 4.8 W kg-1 per W at 900 MHz and 1.8 GHz. However, if one were to consider all possible operational conditions, the placement of the transceiver in front of the eye will give 3.1 and 4.6 W kg-1 per W averaged over 10 g of tissue and 4.7 and 7.7 W kg-1 per W over 1 g of tissue at 900 MHz and 1.8 GHz, respectively.

AB - A new mathematical model of the head has been constructed from a set of serial MRI slices from one subject. Finite-difference time-domain (FDTD) calculations of the specific energy absorption rate (SAR) have been performed on this model with a 2 mm resolution for a generic mobile communication transceiver represented by a quarter-wavelength monopole on a metal box. The antenna was mounted either at the centre or corner of the top face of the box. The frequencies considered were 900 MHz and 1.8 GHz. Three irradiation geometries were considered, a vertical handset in front of the eye and vertical and horizontal orientations at the side of the ear. The effect of a hand grasping the handset was considered. The head model was scaled to represent the head of an infant and a subset of calculations was performed to verify that the SAR deposited in the infant head did not exceed that in the adult. Results are also presented for a half-wavelength dipole. The maximum SAR values produced by the generic transceiver for the horizontal orientation at the side of the head which is the most typical position, averaged over 10 g of tissue at 900 MHz and 1.8 GHz, are 2.1 and 3.0 W kg-1 per W of radiated power. The corresponding values over 1 g of tissue are 2.3 and 4.8 W kg-1 per W at 900 MHz and 1.8 GHz. However, if one were to consider all possible operational conditions, the placement of the transceiver in front of the eye will give 3.1 and 4.6 W kg-1 per W averaged over 10 g of tissue and 4.7 and 7.7 W kg-1 per W over 1 g of tissue at 900 MHz and 1.8 GHz, respectively.

UR - http://www.scopus.com/inward/record.url?scp=0028049572&partnerID=8YFLogxK

U2 - 10.1088/0031-9155/39/10/003

DO - 10.1088/0031-9155/39/10/003

M3 - Article

C2 - 15551530

AN - SCOPUS:0028049572

VL - 39

SP - 1537

EP - 1553

JO - Physics in Medicine and Biology

JF - Physics in Medicine and Biology

SN - 0031-9155

IS - 10

M1 - 003

ER -