Thin Absorber With Dispersive Medium Simulated by Conformal Hybrid Explicit Implicit FDTD Method

In order to accurately analyze the thin absorber with a dispersive medium, an improved hybrid implicit-explicit (HIE) finite-difference time-domain (FDTD) method is investigated. The Dey-Mittra's conformal technique has been introduced into the dispersive medium based on the HIE-FDTD algorithm and the stability of the proposed algorithm is also analyzed. The accuracy and validity of the proposed algorithm are verified by using a newly designed thin-layer absorber with a frequency-selective surface structure, which can achieve more than 90% absorption from 6.2 GHz to 16.9 GHz frequency band. Simulation results validate the accuracy of the proposed algorithm. Meanwhile, the actual experiment demonstrates that the proposed improved algorithm matches the measurement results.