Multiple mode analysis of waveguides using compact FDTD

A traditionally three-dimensional task of dispersion analysis of guided wave structures has been solved by a novel two-dimensional technique called the Compact FDTD (finite-difference time-domain). It not only possesses the versatility of any time domain method but also offers the speed and accuracy of most other analytical techniques. Since a two-dimensional lattice is used as the computational space, the required CPU time and RAM space can be kept affordable even for a personal computer. Two examples of its application are presented. The first is the problem of the hollow rectangular waveguide, for which the analytical solution is readily available. The second is the solution of a more complex case, a boxed microstrip line on sapphire which can be considered as an inhomogeneous anisotropic guided wave structure.<>