Analysis of SAR on human head modeling in metallic enclosures

Abstract

This Paper proposes a pragmatic approach to determine and analyze the effects of radio frequency on human exposure in metallic enclosures. A scenario in which a mobile phone is used inside partially closed elevator and fully closed elevator are considered. Elevators are metallic enclosures but still known to have resonance and reflection effects, thereby increasing electric field strength and resulting of human exposure to electromagnetic absorptions. So this paper examines and compares the levels of absorption in terms of SAR values under various conditions. In this paper homogeneous human phantom with dielectric properties is designed and its interaction is studied with IFA antennas under three conditions free space, elevators in partially closed and full closed conditions. The results show that SAR values are increased in partially closed elevator and greatly increased in fully closed elevators as compared to free space for 900MHz band. The method of computation uses MOM and this is enabled by FEKO software.

An analysis method of effect of linear polarized electromagnetic exposure from mobile phone to human head with various incident angles

“…Human head is modelled as a homogeneous spheroid like paper [19] and is subdivided as the procedure of MoM. The human head is modelled as a spheroid to simplify many complex details and arbitrary surface in human head, spheroid has the most same geometry with human head among other three dimensional geometry.…”

“…Based on these works we need to pay more attention on the danger of electromagnetic exposure. These works [7][8][9][10][11][12][13][14][15][16][17][18][19][20][21] have investigated several parameters which can affect SAR, they are mobile phone's transmit power, antenna, antenna radiation pattern, frequency, polarization, the gap bet ween mobile phone and the human head, and the human head geometry. Each of these parameters has been computed with various method, including vertical and horizontal polarization.…”

“…There are various numerical methods to solve the electromagnetic problem, namely FEM, MoM, FDTD, FVTD, DWP, DWT, TLM, Monte Carlo etc. In several previous works [7][8][9][10][11][12][13][14][15][16][17][18][19][20][21], MoM and FDTD are two methods mostly used in counting electric field in the human body and head. MoM is a frequency based method and it has a better accuracy than FDTD [18].…”

“…Several works have investigated the effect of electromag netic exposure to the human head [7][8][9][10][11][12][13][14][15][16][17][18][19][20][21], mostly the results show that the value of SAR is less than safety standard, but in some cases it is found that SAR is higher, namely the electromagnetic exposure of an omnidirectional antenna [9], a circumstance where the human is about one meter radius from base station [18], and human uses mobile phone in a closed elevator [19]. Based on these works we need to pay more attention on the danger of electromagnetic exposure.…”