Fig. 2

Maps of (a, c) \(\vert \rho _{yy}\vert\) and (b,d) \(\vert \rho _{xx}\vert\) in (f,S)-plane, for a single array of U-shaped subwavelength resonators placed on the substrate being 3 mm thick, with permittivity \(\varepsilon _s=5\) at \(\theta =0^{\circ }\). The lattice period is \(p=15~\text{ mm }\) (a, b) and \(p=22~\text{ mm }\) (c, d).