Efficient Implementations of SC-PML for Arbitrary Media Using DSP Techniques

Through the digital signal processing (DSP) techniques, two simple implementations of the stretched coordinate perfectly matched layer (SC-PML) are proposed in this letter. Specially, they are based on the bilinear
Z
-transform and matched
Z
-transform methods, respectively. In addition, incorporating the concept of generalized material independent PML into these formulations enable them to be completely independent of material properties. Thus, these new implementations can be used to terminate the finite-difference time-domain lattices composed of arbitrary media. As for resource utilization, the proposals can guarantee that only one auxiliary variable is needed for each field component in the whole PML regions. A brief comparison of the number of floating-point operations and constant coefficients successfully shows that they can achieve a bit higher efficiency compared with other published efficient SC-PML implementations. Finally, two numerical examples of electromagnetic waves radiating in vacuum and soil half-space are provided to validate these DSP-based algorithms.