Rigorous ADI-FDTD analysis of left-handed metamaterials in optimally-designed EMC applications

摘要

Purpose - The paper seeks to investigate the precise time-domain modelling and broadband performance optimisation of 3D EMC structures formed by composite left-handed metamaterials. Design/methodology/approach - A frequency-dependent alternating-direction implicit finite-difference time-domain method is introduced. Developing a class of multi-directional curvilinear schemes for double-negative media, the unconditionally stable algorithm forms robust lattice tessellations and provides advanced models complicated media interfaces. Moreover, the erroneous refractions at the metamaterial boundaries are systematically analysed through dynamic stencil configurations and powerful perfectly matched layer absorbers. Findings - The paper finds that the proposed technique leads to convergent discretisations that resolve all propagation bandwidths and enhances the design of promising periodical devices loaded by substrates of thin wires and split-ring resonators. Furthermore, its versatile character subdues dispersion deficiencies far beyond the usual stability criteria. Numerical validation, addressing various up-to-date EMC devices like coupled antennas, waveguides, high-pass filters and absorber linings in test facilities, confirms the merits of the algorithm. Originality/value - The novel methodology offers an advanced nodal control process which drastically suppresses the serious dispersion errors of existing approaches as time-step exceeds the Courant limit. The resulting grids can support coarse resolutions, while the general curvilinear framework, along with the ADI rationale, allows the accurate approximation of demanding permittivity and permeability constitutive profiles. Hence, high accuracy and confined computational overhead are achieved without the need of laborious assumptions.