Effect of Shape, Size and Electrical Properties on Specific Absorption Rate (SAR)

  • M. A. A. Karunarathna Department of Electronics, Faculty of Applied Science, Wayamba University of Sri Lanka, Kuliyapitiya, Sri Lanka
  • C. A. N. Fernando Department of Electronics, Faculty of Applied Science, Wayamba University of Sri Lanka, Kuliyapitiya, Sri Lanka
  • P. Samarasekara Department of Physics, Faculty of Science, University of Peradeniya, Sri Lanka

Abstract

This paper presents the dependency of SAR distribution in the human brain and eye on the shape, size, and electrical properties for different frequencies. Calculations were carried out using the Finite Difference Time Domain (FDTD) Method. The results indicate that the SAR distribution does not much depend on the shape and size but it depends mainly on the electrical properties of the tissues. There is a drop in the magnitude of the SAR in the brain when moving from a cubical model to the spherical model. There is a magnitude drop in the eye, when going from a spherical model to the cubical model. For both brain and eye, when the size is decreased, the volume is reduced and therefore the electromagnetic energy absorption goes up. The human eye at 2500 MHz was considered to observe how the electrical properties of the tissues affect the electromagnetic energy absorption in an organ. When relative permittivity is perturbed in small percentages with conductivity remaining unchanged; the value of the maximum SAR also changes by small values. However, both these cases, when the electrical properties are changed, the location of maximum SAR remains unchanged. It is exactly at the center of the eye.

Downloads

Download data is not yet available.

References

[1] MAA Karunarathna, CAN Fernando and P Samarasekara, ” RF Radiation Distribution & Corresponding Exposure Levels Due to Mobile Base Stations in Sri Lanka ”, International Journal of Advanced in Science, Engineering and Technology (IJARSET), Vol.6, Issue 1, January 2019, pp. 7909 - 7916.

[2] M. A. A. Karunarathna and I. J. Dayawansa, Energy absorption by the human body from RF and microwave emissions in Sri Lanka, Sri Lankan Journal of Physics, 7, (March 2006) 35-47.

[3] MAA Karunarathna, CAN Fernando and P Samarasekara, ” Experimental Observations & Comparison on RF Emissions Due to Mobile Base Station Antennas in Sri Lanka”, International Journal of Advanced in Science, Engineering and Technology (IJARSET), Vol.5, Issue 4, 18th April 2018, pp. 5526 - 5533.

[4] MAA Karunarathna, CAN Fernando and P Samarasekara,” Assessment of RF Exposure Levels Occur Due to Mobile Base Station Antennas in Sri Lanka”, International Journal of Advanced Scientific Research and Management (IJASRM), Vol.2 number 12, 20th December 2017, pp. 11 - 17.

[5] Hsing-Yi Chen, Hou-Hwa Wang, Current and SAR Induced in a Human Head Model by the Electromagnetic Fields Irradiated from a Cellular Phone, IEEE Trans.on Microwave Theory Tech.,42, (1994) 12.

[6] Allen Taflove, Morris E. Brodwin, Computation of the Electromagnetic Fields and Induced Temperatures Within a Model of the Microwave –Irradiated Human Eye, IEEE Trans.on Microwave Theory Tech., 23, (1975) 888.

[7] Matthew N.O. Sadiku, Numerical Techniques in Electromagnetics, Florida: CRC Press, p.179-204, 1992.

[8] Dennis M. Sullivan, David T. Borup and OM P. Gandhi, Use of Finite-Difference Time-Domain Method in Calculating EM Absorption in Human Tissues, IEEE Trans. on Biomedical Engineering, 34, (1987)2.

[9] Spiegel, R.J., A review of numerical models for predicting the energy deposition and resultant thermal response of humans exposed electromagnetic fields, IEEE Trans. Microwave Theory Tech., 23, (1975), p.623-660.

[10] C. Gabriel, Computation of the dielectric properties of body tissues at RF and microwave frequencies, Tech. Rep. AL/OE-TR (Brooks Air Force, Brooks AFB, TX, 1996).
Published
2019-06-25
How to Cite
KARUNARATHNA, M. A. A.; FERNANDO, C. A. N.; SAMARASEKARA, P.. Effect of Shape, Size and Electrical Properties on Specific Absorption Rate (SAR). International Journal of Research and Engineering, [S.l.], v. 6, n. 3, p. 607-611, june 2019. ISSN 2348-7860. Available at: <https://digital.ijre.org/index.php/int_j_res_eng/article/view/380>. Date accessed: 16 july 2019. doi: https://doi.org/10.21276/ijre.2019.6.3.1.