An Iterative FDTD/MoM Technique for Assessing Coupling Effects in Front of Base-Station Antennas

In this study, we used an iterative numerical technique, which combines the finite-difference time-domain (FDTD) method with the method of moments (MoM), to investigate the coupling effect between a base-station antenna operating at 900 MHz and a worker in front of it. The numerical model of the antenna was a realistic representation of a commercially available array of dipoles, whereas for the worker a numerical phantom at 5 mm resolution, created from medical imaging of an adult male, was used. Rao-Wilton-Glisson (RWG) triangular elements were employed in the implementation of the MoM used to solve for the surface currents on the antenna structure. The total-field scattered-field formulation of FDTD was used in the computational domain, which contained the numerical phantom of the worker. An intermediate Huygens surface was introduced to establish an iterative procedure, which allowed us to calculate the influence of the human body on the radiating dipoles. It was found that using this iterative approach the whole body absorption near the antenna varied from the case when no coupling was considered.