PROJECT TITLE :

DGTD Analysis of Electromagnetic Scattering From Penetrable Conductive Objects With IBC

ABSTRACT:

To avoid simple volumetric discretization, a discontinuous Galerkin time-domain (DGTD) method integrated with the impedance boundary condition (IBC) is presented during this paper to analyze the scattering from objects with finite conductivity. Two situations are considered. 1) The skin depth is smaller than the thickness of the conductive volume. two) The skin depth is larger than the thickness of a skinny conductive sheet. For the primary scenario, a surface impedance boundary condition (SIBC) is employed, whereby the surface impedance typically exhibits a complicated relation with the frequency. To include the SIBC into DGTD, the surface impedance is 1st approximated by rational functions within the Laplace domain using the fast relaxation vector-fitting (FRVF) technique. Via inverse Laplace transform, the time-domain DGTD matrix equations can be obtained conveniently in integral form with respect to time t. For the second situation, a transmission IBC (TIBC) is used to include the clear effects of the fields. Within the TIBC, the tangential magnetic field jump is connected with the tangential electric field via the surface conductivity. In this work, a specifically designed DGTD algorithm with TIBC is developed to model the graphene up to the terahertz (THz) band. In order to incorporate the TIBC into DGTD while not involving the time-domain convolution, an auxiliary surface polarization current ruled by a 1st-order differential equation is introduced over the graphene. For open-region scattering issues, the DGTD algorithm is further hybridized with the time-domain boundary integral (TDBI) method to carefully truncate the computational domain. To demonstrate the accuracy and applicability of the proposed algorithm, many representative examples are provided.