Experimental assessment of electric field levels emitted by UHF TV broadcasters

Abstract

Operation of high power broadcast transmitters in populated areas is accompanied with concerns regarding human exposure to emitted electromagnetic fields and related safety issues. In this paper we present the results of in situ measurements of electric field levels emitted by TV broadcasters operating in UHF frequency band. Measurements are conducted in far field zone, with calibrated spectrum analyzer NARDA SRM 3006, capable of capturing separately contribution of each transmitter/channel. Measurement locations are selected to include urban (mostly) and rural environments, indoor and outdoor spots, LOS and NLOS positions, and also different heights from the ground level. Software post processing of measured TV transmitter electric field samples in typical environments, reveal that highest averaged value of electric field is 102.73dB $\mu \mathrm {V} /\mathrm {m}$, captured in outdoor environment - LOS position. This corresponds to channel 31 transmitter, with Effective Radiated Power 15 kW, broadcasting in frequency 551.250 MHz. Most of measured electric field values for outdoor environments are in the range 7080dB $\mu \mathrm {V} /\mathrm {m}$, while for indoor environments they range in 7075dB $\mu \mathrm {V} /\text{m}$. All measured samples of electric fields emitted by TV broadcasters are below the reference levels given by ICNIRP. The results of our measurement campaign are compared with results of similar studies conducted in different countries and results of comparative analysis are given in paper.