An Efficient Unconditionally Stable FDTD Method for Analyzing Composite Right/Left-Handed Transmission Line

For analyzing the composite right/left-handed (CRLH) transmission line (TL) problems, an efficient unconditionally stable (US) finite-difference time-domain method is proposed in the letter. First, based on Kirchhoff's voltage law and Kirchhoff's current law, the CRLH TL equations are derived and rewritten in matrix form. Then, by adopting the Crank-Nicolson time split technique, and carrying out some transformations to achieve an equivalent formulation, the US scheme for the implementation of the CRLH TL equations can be obtained. Two numerical examples are used to validate the efficiency and accuracy of the proposed method in analyzing a CRLH TL and pure left-handed TL.