A Wideband ADI-FDTD Algorithm for the Design of Double Negative Metamaterial-Based Waveguides and Antenna Substrates

An enhanced 3-D alternating-direction implicit finite-difference time-domain method for the systematic analysis of double negative metamaterial-based waveguide and antenna devices is presented in this paper. Being fully frequency-dependent, the new scheme introduces a set of generalized multidirectional operators which incorporate the suitable Lorentz-Drude model and subdue inherent lattice deficiencies for broad spectra. So dispersion errors, as time-steps exceed the Courant limit, are drastically minimized yielding fast and accurate solutions for propagating and evanescent waves. The technique is applied in the design of microwave structures, realized via the prior model or networks of thin wires and split-ring resonators. Numerical results certify its merits, without requiring elongated simulations and excessive overheads