Unconditionally Stable CNAD- and BT-Based CFS-PML Implementation for Truncating Anisotropic Magnetic Plasma

In this letter, an unconditionally stable and efficient implementation of the complex frequency-shifted perfectly matched layer (CFS-PML) based on the Crank-Nicolson-approximate-decoupling (CNAD) finite-difference time-domain method (FDTD) scheme and the bilinear transform method is developed for terminating anisotropic magnetic plasma. The dispersive and anisotropic magnetic plasma can be simulated by the auxiliary differential equation method. The proposed CFS-PML implementation can not only attenuate evanescent waves but also reduce late-time reflections. Furthermore, the proposed algorithm not only has the advantage of the conventional FDTD method in terms of absorbing electromagnetic waves but also takes advantage of the unconditional stability of the origin CN-FDTD scheme in terms of reducing the computational time. A numerical example is provided in the 2-D computational domain to indicate the effectiveness of the proposed CFS-PML scheme. The results show that the proposed CFS-PML is unconditionally stable for the time step, which surpasses the Courant limit, and it is suitable for truncating the anisotropic magnetic plasma.