High-Efficiency AA-FLOD-FDTD Method with Wideband Low Numerical Dispersion Error

A novel one-dimensional finite-difference time-domain method, denoted as AA-FLOD-FDTD method, is proposed to efficiently minimize numerical dispersion error (NDE) across a wide bandwidth, while maintaining high computational efficiency. Though the conventional FLOD-FDTD method excels in computational speed, it still has a limitation in accuracy. To address this issue, we integrated the optimized artificial anisotropy parameters into the FLOD-FDTD method, enabling it to dramatically reduce the NDE (to less than 15%) under large time steps and coarse grid conditions. The proposed method is first proven to be unconditionally stable. Then, comprehensive simulations validated the AA-FLOD-FDTD method's excellent performance in efficiency and accuracy, as well as the capability to maintain low dispersion error across a wide bandwidth.