SAR in a Human Head Depending on the Arrangement of Antenna of Mobile Phone

이동통신단말기 안테나 배치에 따른 두부의 전자파 흡수율

  • 이애경 ;
  • 김진석 ;
  • 이광천 ;
  • 조광윤
  • Published : 1999.12.01


Presently, the retractable phone with a whip antenna composed of a helix and a monopole is most widely used for cellular mobile communications. However, since the length of the monopole is usually about λ/4, the strong radiated electric fields are produced in the region where the auricle of a head is contacted directly. This field distribution results in high specific absorption rates(SAR's) in the head. In this paper, SAR distributions and local SAR values for the inversely shaped phone(ISP) whose antenna arrangement is opposite to the original retractable phone(ORP) are compared with those for the ORP. This phone is accomplished by mounting the $\lambda$/4-whip antenna on the bottom, not on the top of the handset. The time-averaged field distribution in a computational space including a human model and a phone model is computed using the finite-difference time-domain(FDTD) method. SAR distributions and local SAR values for these phones are calculated with the field distributions. An anatomical head model and an approximate hand model were used to consider a real situation. From the analyzed data, it is shown that this arrangement of the antenna considerably reduces the spatial peak SAR in a human head.



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