Time domain integral equation based analysis for thin scatterers using impedance boundary conditions

Impedance boundary conditions (IBC) relate electric and magnetic fields tangential to smooth material surfaces of highly conductive objects. The usage of IBC models in electromagnetic field simulators eliminates the need to model a scatterer´s internal fields, thereby leaving only exterior scattering problems to be solved. In this paper, the time domain integral equation (TDIE) solver for analyzing scattering from non-transparent IBC objects is extended to analyze scattering from electrically thin, and potentially penetrable IBC surfaces. Two coupled TDIE that are very similar to those in Chen et al. (2004) are established and solved by marching-on-in-time (MOT). The proposed scheme is verified by means of several numerical examples.