Estimation of a partial transmitter contribution to the total electromagnetic field exposure, in a multi-transmitter environment

摘要

The equipment used for radiation hazard evaluation usually is based in measuring the total electric field strength over a frequency bandwidth of interest. However, because of the fact that the defined Reference Levels (RL) according to the ICNIRP Guidelines or other specific legislation are frequency dependent, the compliance of a particular RF or microwave transmitter and its contribution to the total received electromagnetic energy at a given measurement location is not easily identifiable. On the other hand, narrowband measurements can be used to determine the incident electric field from every single transmitter. However, in such a case, a large number of measurements are required in order to estimate its contribution to the total electric field strength and consequently to check for compliance with the legislation limits, due to the fact that directional antennas should be used. In this work a method is presented for determining: the total electric field from a particular direction to a specific point of a measurement location (e.g. in the vicinity of a mobile base station), the angle of maximum incident electric field and the total exposure quotient from the sources laying at that particular location in a frequency band of interest.