Comparison of different techniques for the treatment of lossy dielectric/magnetic bodies within the method of moments formulation

The present paper aims at describing and comparing different approaches to model lossy dielectric and magnetic materials within the framework of the M ethod of Moments (MoM). Classical techniques such as the surface equivalenc e principle (SEP) and the volume equivalence principle (VEP) are briefly re viewed, but the main focus is on faster techniques, which also require less memory. For high frequency applications, Physical Optics (PO) approximatio ns for the equivalent surface current densities are presented, and special Green's functions (GF) are introduced to deal with certain canonical geomet ries. The hybridisation of MoM with other techniques is discussed as well, as are efficient solutions for dielectrically coated wires and geometricall y thin dielectric sheets (TDS). Several examples are considered, and the va rious techniques are compared with respect to accuracy and computational co st.