Evaluation of SAR reduction for mobile communication handsets

We propose SAR evaluation and reduction methods based on power conservation. After defining SRF (SAR reduction factor) for a more quantitative discussion of effective SAR reduction methods, many kinds of simulation have been performed. From many parametric studies, it has been shown that even though the use of ferrite material not only reduces the SAR in the head but also the radiated power, it reduces the SAR in head more considerably than the radiated power. Thus the ferrite material may be used in this sense as one of the SAR reduction methods. We have also shown that in a typical position of handsets over a human head, the SAR when using a folder type is about 30% smaller than that when using a flip type.