The effects of ground characteristics on near-field modeling of HF transmission sites for EMC compliance testing

The aim of this work is to seek a modeling and measurement methodology to assess compliance of BBC World Service HF transmitter sites with ICNIRP safety guidelines. It relates to near-field incident field levels and the SAR and current densities they induce in the body, and aims to determine the most restrictive quantities. Compliance testing HF transmission sites near-field to predict the possibility human exposure exceeding the ICNIRP guidelines. This paper compares the near-field field strength distributions for a HF transmitter positioned above a perfect electrical ground and above a real homogenous ground. The Skelton C BBC HF curtain array has been modelled using both by MoM and FEM methods. The results presented assist in mapping field distributions in the vicinity of high power HF transmission sites and can be used to assess both occupational and public exposure levels.