A multimodal calibration technique for waveguide devices

In this paper we demonstrate a general multimodal calibration technique allowing the experimental characterization of overmoded waveguides and waveguide devices. The proposed technique produces a measured Generalized Scattering Matrix, and proves to be robust and accurate, as demonstrated by the excellent agreement between measured and analytical data for a set of empty waveguides. As a byproduct, the technique allows the measurement of the propagation constant of waveguides having arbitrary cross-sections.