Total field/scattered field formulation

Abstract

This paper discussed about another technique that introduces far-zone sources (plane wave) into the FDTD computational domain is the Total Field/Scattered Field (TF/SF) method presented by Umashankar and Taflove. In the scattered field (SF) method, discussed before, the scattered fields are defined in the entire computational domain and the incident fields are imposed on the entire computational domain. Unlike the SF method, in the TF/SF method the computational domain is divided into two regions: a total fields region, in which all objects are placed, and a scattered fields region that surrounds the total fields region. Then, the incident plane wave is imposed on the boundary between these two regions to compensate for the discontinuity that arises due to the difference in the field values on the two sides of the boundary. The concept will be illustrated for the one-dimensional case first, and then the discussion will be extended to the three-dimensional case.