EMC compliance testing of BBC World Service HF transmitter sites

The aim of this work is to seek a modelling and measurement methodology to assess compliance of BBC World Service HF transmitter sites with ICNIRP safety guidelines relating to near zone incident field levels and the SAR and current densities they induce in the body, and to determine the most restrictive quantities. A typical HF curtain array is modelled over a Sommerfeld ground, and near zone cross-polar vertical fields are shown to be as significant as their horizontal co-polar counterparts, even without confounding support structures being considered. Results for `virtual family' phantom models exposed to plane wave fields are described and compared with HPA data. A hybrid computational technique to illuminate phantoms with realistic near zone antenna fields is discussed, together with a corroborative field measurement strategy, focussing towards development of a general evaluation paradigm for all HF installations.