Dipole-Moment Source Modeling Using Near-Field Scanning With a Finite-Impulse-Response Filter

This article demonstrates that if 2-D divergence operations are used, the electric and magnetic fields in the planar near-field are, respectively, determined using the underlying equivalent electric dipole moments and magnetic dipole moments. A finite impulse response (FIR) filter is used to rapidly determine a feasible dipole moment model using the 2-D divergence of near-field scanning fields. To increase the accuracy of the solution, an iterative process that uses a FIR filter with a least-squares method is proposed. The regularization technique for stabilizing the least-squares solution is studied and a criterion for the selection of regularization coefficient is derived. The proposed method is validated using several examples and is compared with the conventional method, capable of obtaining a more accurate solution in significantly less computation time.