Rigorous Analysis of the Parallel-Plate Waveguide by the Hybrid Mode Formulation: From the TEM mode to the Surface Plasmon Polariton - Leal-Sevillano C; Ruiz-Cruz J; Montejo-Garai J; Rebollar J (2011 30th Ursi General Assembly And Scientific Symposium, Ursigass 2011, 2011)