Advanced Modeling of Rectangular Waveguide Devices With Smooth Profiles by Hierarchical Model Reduction

We present a new method for the analysis of smoothly varying tapers, transitions, and filters in rectangular waveguides. With this aim, we apply a hierarchical model (HiMod) reduction to the vector Helmholtz equation. We exploit a suitable coordinate transformation and, successively, we use the waveguide modes as a basis for the HiMod expansion. This allows us to model the electromagnetic field efficiently and compactly without incurring on relevant simplifications. We show that accurate results can be obtained with an impressive speed-up factor when compared with standard commercial software based on a 3-D finite element discretization.