Simple evaluation method of estimating local average SAR

Generally, the E-field probe method and the thermographic method are used for the measurement of the specific absorption rate (SAR). However, the thermographic method is not efficient to measure the local average SAR. Therefore, in this paper, the simple evaluation method of estimating local average SAR using the SAR distribution on specific planes and axes has been proposed. First, the limit of simplification has been investigated when four types of antennas, which are a half-wave dipole antenna, monopole antenna mounted on a metal box, planar inverted F antenna, and a half-wave dipole antenna with a planar reflector, are close to the COST244 cubical and spherical head model. Next, the effect of the distance and the frequency on the average SAR using the proposed method has been evaluated. Finally, the local average SAR in the realistic head model using the distribution of the specific plane and axes has been investigated. From these investigations, the agreement between the local 10-g average SAR calculated by the data in the optimum plane or axes and that in the three dimensions is within /spl plusmn/10% in almost all cases.