Figure 4

(a) Simulated amplitude (top panel) and phase (lower panel) for the electric field distributions at 23.3 GHz within the substrates and above the air/dielectric boundaries (interfaces defined by dotted white lines) for the nonradiating 2-L PPW (above) and the 2L-PPW LWA (below). Both simulated structures were excited by a nondirective SWL at the center and with a coplanar waveguide feeding line; (b) TM LW normalized phase and attenuation constants (upper and lower plot, respectively) defining the 2L-LWA (perturbed 2L-PPW) obtained using the MoM dispersion analysis on the linearized unit cell. Parameters: period p = 5 mm, slot width w = 1.4 mm, \({\varepsilon }_{{{\rm{r}}}_{1}\mathrm{[2]}}=\mathrm{10.2[3]}\), and h₁ = 1.27 mm. A parametric analysis has been performed for different values of the superstrate thicknesses h₂.