Exploiting Port Responses for Wideband Analysis of Multimode Lossless Devices

This article presents a novel method for the wideband analysis of lossless arbitrary multimode waveguide junctions. The analysis is based on a compact model obtained by the frequency response at the ports only. The model makes use of the generalized scattering matrix (GSM) and its frequency derivative and is capable to deal with a large number of modes (also below cutoff) with a small number of frequency samples.