Wide-Angle Elimination of TF/SF-Generated Spurious Waves in the Nonstandard FDTD Technique

In the radar-cross section (RCS) analysis of electrically large objects via the nonstandard finite-difference time-domain method, spurious reflection or scattering waves arise from the total-field/scattered-field (TF/SF) separation surface. To suppress such waves, a novel TF/SF separation scheme with a multilayered structure for the suitable assumed-known incident-field calculations, is proposed. The scheme, which uses two adjustable parameters, is numerically verified and found to attain a drastic reduction of the spurious scattered field over a wide-angle regime, unlike previous TF/SF approaches, which is necessary for accurate RCS studies.