Improvement of Numerical Accuracy in FDTD Modelling of Left-Handed Metamaterials

This paper presents a finite-difference time-domain (FDTD) modelling of left-handed material (LHM). Both the auxiliary differential equation (ADE) method with a field averaging technique and an alternative differential equation method with the arithmetic mean of permittivity of different materials are used to take into account the material frequency dispersion as well as accurately model the interfaces of the LHM slab. The transmission coefficients calculated from analytical formulations are used to validate the FDTD simulations. The numerical results show that the sub-wavelength imaging property is not sensitive to the transverse dimension of the LHM slabs.