A New Design of Cell Phone Body for the SAR Reduction in the Human Head
Keywords:
Antenna, FDTD method, human hand model, mobile body, SARAbstract
In this paper, a new design of cell phone body is presented to reduce the specific absorption rate (SAR) in the human head. The SAR in the human head and total absorbed power by the cell phone user are calculated along with antenna performances in terms of radiation efficiency and directivity to validate the effects of cell phone body. It is found that the SAR in the head is reduced significantly for both the lower and upper global systems for mobile (GSM) frequency band. The new mobile body provides 63.8% reduction in the SAR at 900 MHz and 69.2% reduction at 1800 MHz in comparison of without mobile cover configuration. Moreover, the mobile casing improves the radiation efficiency 6% and 7% in the lower and the upper GSM frequency band respectively.
Downloads
References
I. Guideline, “Guidelines for limiting exposure to time-varying electric, magnetic, and electromagnetic fields (up to 300 GHz),” Health Phys., vol. 74, pp. 494-522, 1998.
M. I. Hossain, M. R. I. Faruque, M. T. Islam, and N. H. M. Hanafi, “Application of auxiliary antenna elements for SAR reduction in the human head,” Advanced Materials Research, vol. 974, pp. 288- 292, 2014.
M. R. I. Faruque, N. A. Husni, M. I. Hossain, M. T. Islam, and N. Misran, “Effects of mobile phone radiation onto human head with variation of holding cheek and tilt positions,” Journal of Applied Research and Technology, vol. 12, no. 5, pp. 871-876, 2014.
Federal Communications Commission, Evaluating Compliance with FCC Guidelines for Human Exposure to Radiofrequency Electromagnetic Field, 2001.
IEEE Standard for Safety Levels with Respect to Human Exposure to Radio Frequency Electromagnetic Fields, 3 kHz to 300 GHz - Amendment 1: Specifies ceiling limits for induced and contact current, clarifies distinctions between localized exposure and spatial peak power density, IEEE Std. C95.1a-2010 (Amendment to IEEE Std. C95.1- 2005), pp. C1-9, 2010.
O. Kivekas, J. Ollikainen, T. Lehtiniemi, and P. Vainikainen, “Bandwidth, SAR, and efficiency of internal mobile phone antennas,” Electromagnetic Compatibility, IEEE Transactions on, vol. 46, pp. 71-86, 2004.
K. Yanase and A. Hirata, “Effective resistance of grounded humans for whole-body averaged SAR estimation at resonance frequencies,” Progress In Electromagnetics Research B, vol. 35, 2011.
H. Y. Chen and W. Y. Chiou, “Material studies on cellular phones for reducing SAR in a human head model,” in Antennas and Propagation Society International Symposium, 2002. IEEE, pp. 448- 451, 2002.
K. Chan, K. Chow, L. Fung, and S. Leung, “Effects of using conductive materials for SAR reduction in mobile phones,” Microwave and Optical Technology Letters, vol. 44, pp. 140-144, 2005.
J. Pretorius, “Design and manufacture of a ferrimagnetic wave absorber for cellular phone radiations,” in Electron. Devices for Microwave and Optoelectronic Applications, 2004 EDMO 2004, 12th International Symposium on, pp. 119- 123, 2004.
M. I. Kitra, C. J. Panagamuwa, P. McEvoy, J. Vardaxoglou, and J. R. James, “Low SAR ferrite handset antenna design,” Antennas and Propagation, IEEE Transactions on, vol. 55, pp. 1155-1164, 2007.
M. T. Islam, M. R. I. Faruque, and N. Misran, “Design analysis of ferrite sheet attachment for SAR reduction in human head,” Progress In Electromagnetics Research, vol. 98, pp. 191-205, 2009.
S. il Kwak, D. U. Sim, J. H. Kwon, and H. Do Choi, “Comparison of the SAR in the human head using the EBG structures applied to a mobile handset,” in Microwave Conference, 2007, European, pp. 937- 940, 2007.
R. Ikeuchi, K. H. Chan, and A. Hirata, “SAR and radiation characteristics of a dipole antenna above different finite EBG substrates in the presence of a realistic head model in the 3.5 GHz band,” Progress In Electromagnetics Research B, vol. 44, pp. 53-70, 2012.
M. I. Hossain, M. R. I. Faruque, M. T. Islam, and M. H. Ullah, “A new wide-band double-negative metamaterial for C- and S-band applications,” Materials, vol. 8, no. 1, pp. 57-71, 2014.
M. R. I. Faruque, M. Islam, and M. Ali, “A new design of metamaterials for SAR reduction,” Measurement Science Review, vol. 13, pp. 70-74, 2013.
G. F. Pedersen and J. B. Andersen, “Integrated antennas for hand-held telephones with low absorption,” in Vehicular Technology Conference, 1994 IEEE 44th, pp. 1537-1541, 1994.
J.-N. Hwang and F.-C. Chen, “Reduction of the peak SAR in the human head with metamaterials,” Antennas and Propagation, IEEE Transactions on, vol. 54, pp. 3763-3770, 2006.
C. H. Li, E. Ofli, N. Chavannes, and N. Kuster, “Effects of hand phantom on mobile phone antenna performance,” Antennas and Propagation, IEEE Transactions on, vol. 57, pp. 2763-2770, 2009.
CST Microwave Studio, 3D EM Simulation Software [Online], available: https://www.cst. com/Products/CSTMWS.[Accessed:01-Nov2014].
