Title :
Effects of ferrite sheet attachment to portable telephone in reducing electromagnetic absorption in human head
Author :
Wang, Jianqing ; Fujiwara, Osamu ; Takagi, Tasuku
Author_Institution :
Dept. of Electr. & Comput. Eng., Nagoya Inst. of Technol., Japan
Abstract :
In order to reduce the spatial peak specific absorption rate (SAR) in a human head due to a portable telephone, we have proposed attaching a ferrite sheet to the portable telephone. In this paper, the mechanism of SAR reduction is reviewed and then the effects of the attachment location and size, and the material properties of ferrite sheet on the SAR reduction are investigated by using the finite-difference time-domain (FDTD) method in conjunction with a detailed human head model. Their effects on the antenna radiation efficiency are also given. The results lead to a guide to choosing and designing a ferrite sheet with the maximum SAR reducing effect for portable telephones
Keywords :
antenna radiation patterns; biological effects of fields; electromagnetic wave absorption; ferrites; finite difference time-domain analysis; health hazards; mobile antennas; monopole antennas; safety; telephone sets; FDTD method; SAR reduction; antenna performance; antenna radiation efficiency; electromagnetic absorption reduction; ferrite sheet attachment; finite-difference time-domain method; health hazards; human head; human head model; material properties; monopole antenna; portable telephone; safety guidelines; spatial peak specific absorption rate; Directive antennas; Electromagnetic wave absorption; FCC; Ferrites; Finite difference methods; Humans; Joining processes; Material properties; Telephony; Time domain analysis;
Conference_Titel :
Electromagnetic Compatibility, 1999 IEEE International Symposium on
Conference_Location :
Seattle, WA
Print_ISBN :
0-7803-5057-X
DOI :
10.1109/ISEMC.1999.810126
