Effects of electromagnetic absorption toward a human head due to variation of its dielectric properties at 900 and 1900 MHz with different antenna substrates

Abstract

The aim of this paper is to analyze the effects of electromagnetic (EM) energy absorption at 900 and 1900 MHz when the human head ' s dielectric properties are varied. This radiation is measured in terms of specific absorption rate (SAR). The characteristics of the helical antenna and its substrates with variation of the human head dielectric properties were simulated via the finite-difference time domain (FDTD) method using the CST Microwave studio. The human head dielectric properties are manipulated by increasing and decreasing 10 % and 20 % of each dielectric property. In this study, SAR values increase with increase of the human head ' s conductivity, while increase of permittivity and densities decreases it. A helical antenna with a substrate of FR4 resulted in higher SAR values in all frequencies. The head SAR values are higher in the upper frequency exposures. The helical antenna with a substrate of Rogers RO3006 (loss free) was found to be the best-tested substrate, which contributed toward much lower SAR values in all GSM frequency bands.

Printed microstrip- fed circular patch antenna for wireless communication

“…In designing antennas for wireless communication, it is very important to analysis SAR values of the proposed antenna. Several investigation has been performed about SAR reduction [10][11][12][13]. In this paper, SAR analysis has been performed, where the reference power of the wireless device is set to 500mW.…”

Assessment of specific absorption rate reduction in human head using metamaterial

“…The most used method to solve the electromagnetic problem in this area is the finite-difference time-domain (FDTD) method [8][9][10][11][12]. Although, in principle, the solution for general geometries does not require any additional effort with respect to the standard method, the technique requires the definition of a discretised space by assigning to each cell its own electromagnetic properties, which is not an easy process [13][14][15][16].…”