Fig. 3.

Relation between folding angle $\theta$ and dipole distances $D_w$, $D_{\ell }$, and $\mathrm{\Delta }h$ for the mirror stack and inline stack of the Miura-FSS. (A) For the mirror stacking of identical layers, the shades represent the range of the curves for panel angles $\alpha$ between $\mathrm{45}°$ and $\mathrm{70}°$. The green, blue, and orange shades represent how $\mathrm{\Delta }h$, $D_{\ell }$, and $D_w$, respectively, vary with respect to $\alpha$. (B) For the inline stacking, the green shade represents the variation of $\mathrm{\Delta }h$ for panel angles ${\alpha }_t$ (subscript $t$ refers to the top layer) between $\mathrm{52}°$ and $\mathrm{70}°$. The blue and orange dashed lines represent the distances $D_{\ell }$ and $D_w$ between the dipoles of the top and bottom layers. In both A and B, the yellow circles represent the configurations in which percentage bandwidth is $\le 15\%$ (comparable to single-layer Miura-FSS) while black circles represent configurations which can realize broader bandwidth ($>15\%$), and brown circles represent configurations with multiband and multiresonant frequency.