Perfectly matched layers backed with the first order impedance boundary condition for the time-domain finite/element solution of waveguide problems

The first order impedance boundary condition (the first order ABC) is combined with the perfectly matched layer (PML) for the time-domain finite-element (TDFE) simulation of waveguide problems. The formulation is validated by the numerical simulations of waveguide problems. Numerical results clearly show that the PML backed with the first order impedance boundary condition performs better than the PML backed with the perfect electrically conducting (PEC) wall when used to absorb the propagating wave. In the same situation, PML terminated with the first order impedance boundary condition can reduce about 10 dB of the reflection errors compared with that obtained front the PML terminated by PEC wall. Therefore, the proposed boundary conduction can reduce the number of the unknowns and provide an effective mesh truncation for the TDFEM solution of waveguide problems. (C) 2008 Wiley Periodicals, Inc.