Challenges in modelling near field antenna-body interactions

At the end of the nineties, the FDTD simulation of a basic coaxial-MSL transition typically took about an hour; real-life problems were practically impossible to solve without supercomputing resources. Thanks to the tremendous performance boost in hardware and the advent of more efficient simulation technologies, computational power no longer limits to accurately simulate the most complex electromagnetic (EM) problems. As for near field antenna-body interactions, computations of detailed CAD-based radiating sources in the proximity of anatomical human models can be effectively carried out even with inexpensive commercial PCs. For cost and productivity reasons, replacing complex RF measurements by simulations is surely attractive. Then, what is the barrier to the 100%-numerical stage? Without pretending to deliver a comprehensive response to this question, this paper explains why defining an accurate model of a complex wireless device remains a major difficulty. Changing from the viewpoint of radiation performances evaluation to exposure assessment, the authors introduce a novel concept based on the combination of near-field vector measurement and simulation techniques which may offer an alternative to the 100%-numerical, with the advantage to get around source modelling difficulties under certain conditions.