The effects of support structures on near-field exposure levels for HF antennas

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, with consideration of the supporting towers. This work aims 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. 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.