Comparative characterization of the electromagnetic near field radiated by mobile phones in GSM and UMTS communication technologies

The experimental work focuses on the analysis of the time variation of the radiated power in the immediate vicinity of mobile phones transmitting in the GSM (900MHz) -2^nd generation and in UMTS (1900MHz) -3^rd generation of communication standards during the first 20 seconds of a call. The user usually places the handset near the head while initiating the call. During this period the human exposure level tends to be significant while adaptive power control acts. The static value of the specific absorption rate (SAR) of energy deposition in the head is considered the only standardized quantity to be connected to human protection regulations. However a complete characterization of the power-frequency-time dynamics which depends on a lot of factors in real exposure conditions, needs to also be taken into account for a comprehensive understanding of possible radiation hazards. Therefore a non-standardized, complementary approach is treated in this paper, based on near-field level measurements with a real-time spectrum analyzer.