Complementary perfectly matched layers to reduce reflection errors

A new approach is proposed to reduce the reflection error of a perfectly matched layer (PML) in the frequency-domain finite-element solution of electromagnetics problems. The approach is based on the complementary nature of a PML backed by a perfect electric conductor (PEC) and one backed by a perfect magnetic conductor (PMC). By averaging the solutions obtained by PEC- and PMC-backed PML, the error is reduced by 20 log|R| dB, where R is the reflection coefficient of the PEC- or PMC-backed PML. Numerical results are presented to demonstrate the accuracy of the complementary PMLs.