An Enhanced FDTD Algorithm for Analyzing Inhomogeneous Multilayer Waveguides and Filters

In this paper, a new formulation of the finite difference time domain technique (FDTD) was applied for an efficient hybrid-mode analysis of inhomogeneous planar waveguides and filters. An enhanced analytical formula for the cut-off frequency was also proposed for a three-layer waveguide while the shielding effect was investigated on bandpass filter performance. The computed S-parameters are in good agreement with simulated ones obtained with CST electromagnetic tool.