Hybrid PML-ABC truncation techniques for finite-volume time-domain simulations

Computational domain truncations using pure and hybrid techniques in the framework of the finite-volume time-domain (FVTD) method are presented. Accurate truncation of the split-field perfectly matched layer (PML) using the first-order Silver-Mueller absorbing boundary condition (SM-ABC) provides a substitute for standard perfect electric conductor (PEC) based truncation without extra computational effort. Strategies to adapt SM-ABC for truncating PML and the broadband performance analysis of the FVTD- PML models are explored with supporting numerical results. Numerical reflection coefficients in the range of -75 dB were achieved at normal incidence for a broadband source excitation. A similar analysis at 45 degree incidence angle results in numerical reflection coefficient below -45 dB.