A Partially Implicit FDTD Method for the Wideband Analysis of Spoof Localized Surface Plasmons

A partially implicit finite-difference time- domain (FDTD) method with relaxed stability condition is formulated on the basis of combining the implicit Newmark-Beta and the explicit leapfrog time integrations. Its stability is investigated by the Fourier method. The 2-D open and closed structures supporting spoof localized surface plasmons are analyzed with the presented method. The computational time is reduced in comparison with the traditional explicit FDTD while maintaining the same level of accuracy.