Morán-López, A., J. Córcoles, J. A. Ruiz-Cruz, J. R. Montejo-Garai, and J. M. Rebollar,  "Generalized Scattering Matrix of the discontinuity between an equilateral triangular waveguide and a rectangular, circular or elliptical waveguide",  Microwave Conference (APMC), 2016 Asia-Pacific: IEEE, pp. 1?4, 2016.