Figure 2

(a) Dispersion diagrams for different kinds of waveguides. Here, p = 3 mm, a = 1.5 mm, d = 2.5 mm, h = 5 mm and t = 0.07 mm. The substrate is Rogers RT5880 with the thickness of 1.575 mm, relative permittivity εr = 2.2 and loss tangent 0.0009. The coordinate in the inset is applied throughout this paper. (b) Simulated dispersion diagrams of spoof SPP waveguides with different groove depths d.