Comparison and Evaluation of SAR Induced in Four Human Head models for Two Types of Antennas Used in Mobile Telephones

In this paper, a comparative study of two types of antennas typically used in portable telephones is presented and discussed. These include a half-wavelength dipole and a quarter -wavelength monopole mounted on top of a metal box designed for operating in GSM900, DCS1800 and PCS1900 frequency bands. In this research work, the specific absorption rate (SAR) levels of the dipole antenna is evaluated and compared with that of the monopole antenna. Four different human head models have been implemented: homogenous spherical head, spherical seven layer model, Specific Anthropomorphic Mannequin (SAM) phantom and HUGO human head model. All the simulations are done for three different distances between the antenna and the head model (5 mm, 10 mm and 20 mm). The SAR levels for the head tissues are calculated for and in accordance to the two currently accepted standards: Federal Communications Commission (FCC) and International Commission on Non-Ionizing Radiation Protection (ICNIRP). All numerical simulations are performed using the Ansoft HFSS Software and CST Microwave Studio.