High-Performance Hybrid-FDTD Investigation for Characterizing the Electromagnetic Transmission Attributes of Media With Arbitrary Shapes

Accurately and effectively analyzing the electromagnetic properties of media with arbitrary shapes has always been a difficult and challenging problem in the field of electromagnetic simulation. Traditional methods often encounter issues such as low computational efficiency and insufficient accuracy. To address above problems, this article proposes the hybrid finite-difference time-domain (H-FDTD) method based on the Drude two critical points (Drude2CPs) model. The H-FDTD algorithm introduced encompasses the alternating direction implicit finite difference time domain (ADI-FDTD) method and the dispersive contour path finite difference time domain method based on Drude2CP (DCP-FDTD-D2CP). The ADI-FDTD for non-dispersive case leads to an elevation in computational efficiency. The DCP-FDTD-D2CP algorithm is specifically applicable to the dispersion scenario occurring at the interface between metal and dielectric. In this context, the frequency-dependent formulae employ the trapezoidal recursive convolution (TRC) technique. In addition, the rigorous analysis shows that the proposed H-FDTD algorithm is theoretically stable. To validate its efficacy, a series of numerical examples was carried out, specifically involving metal circular waveguides and slotted coaxial lines. The obtained results indicate that the relative error of this method is maintained below 1%, and the computational efficiency is enhanced by 60% in comparison with the traditional finite-difference time-domain (FDTD) algorithm. Consequently, this method exhibits the characteristics of stability, high precision, and high efficiency. Moreover, it is convenient for simulating and analyzing complex structures.