Optimal modeling of real radio base station antennas for human exposure assessment using spherical-mode decomposition

This article presents an innovative way to derive a radio station antenna model that can match very closely real antennas described by their measurements. The derived model can then be used for the assessment of human exposure to the electromagnetic field in the vicinity of the antennas, including the near field and the interactions with the environment. The technique is based on the principle of decomposing a whole antenna into subantennas enhanced by spherical-harmonic fields decomposition. A singular values decomposition (SVD) is used to find the model parameters. The proposed technique is applied on a real antenna used in mobile networks.