Mutual Interaction of the Measuring Antenna and the Field Source

Hazardous exposure to EMF requires field measurements in the neighborhood of primary and secondary field sources as well as fields disturbed by the presence of materials and the transmission media. Our attention must be focused on the near-field (Fresnel region). The near-field conditions cause further degradation of the near-field EMF measurement´s accuracy as compared to those in the far-field. These difficulties raise doubts about the measuring equipment and its users, and bring frustration to its designers. This paper is devoted to the specific problems of EMF measurements in the near-field and to the analysis of the one of the main factors limiting the measurement accuracy, especially in the near-field. It is focused upon the Mutual interaction of the measuring antenna and the field source, especially dependence of the accuracy of E-field measurement from the structure of the source