The paper presents an original methodology to characterize electromagnetic disturbances radiated from power electronic devices. The approach is based on the substitution of an equivalent set of elemental dipoles for the real system; this set radiates the same near-field. The dipoles are determined from a near-field cartography of the fields obtained with a measurement bench. The parameters of the dipoles are determined by solving an inverse problem. The efficiency of the approach is demonstrated for a 3-D case and for a practical dc-dc converter.