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

Abstract

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.

Keywords

References

  1. FCC, OET Bulletin v.65 Evaluating compliance with FCC guidelines for human exposure to radiofrequency electromagnetic fields(Edition 97-01)
  2. 1998 Asia-Pacific Microwave Conference Proceedings v.2 Electromagnetic energy absorption in a human head for a cellular phone at 835 MHz A. K. Lee;Jin-suk Kim;Hyung-do Choi;Kwang-yun Cho
  3. The Finite Difference Time Domain Method for Electromagnetics Karl S. Kunz;Raymond J. Luebbers
  4. Guidelines for limiting exposure to time-varying electric, magnetic, and electromagnetic fields(up to 300GHz) ICNIRP
  5. Human Exposure to Electromagnetic Fields High Frequency(10kHz to 300GHz)
  6. Mobile Antennas Systems Handbook K. Fujimoto;J. R. James
  7. IEEE Standard for safety levels with respect to human exposure to radio frequency electromagnetic fields, 3kHz to 300GHz IEEE
  8. 한국전자파학회 논문지 v.9 no.6 셀룰라 휴대폰에 의한 인체 두부의 SAR 해석 이애경;최형도;김진석
  9. Radio-Radiation Protection Guidelines for Human Exposure to Electromagnetic Fields Telecommunication Technology Council
  10. 휴대폰 안테나의 배치구조 김금모