A GENERALIZED COMPACT 2-D FDTD MODEL FOR THE ANALYSIS OF GUIDED MODESOF ANISOTROPIC WAVE-GUIDES WITH ARBITRARY TENSOR PERMITTIVITY

In this paper a generalized 2-D FDTD model based on the D, E, and H fi elds for the analysis of guided modes of anisotropic waveguides with a rbitrary tensor permittivity is proposed. With the help of the propose d model, the relationship between the compact complex and real variabl e 2-D FDTD methods is investigated It is found that for certain anisot ropic cases, the complex 2-D FDTD method cannot be reduced to (or repl aced by) the real variable 2-D FDTD method. On the other hand, excitat ion techniques for both the complex and real variable methods are also discussed Numerical results show that using the impulse with complex amplitudes in the excitation is not an essential condition, even for a purely complex 2-D FDTD case. The accuracy and flexibility of the pro posed model are validated and confirmed by comparing numerical results with other techniques. (C) 1998 John Wiley & Sons, Inc.