Angular insensitive frequency selective surfaces based on meander lines

We propose a design of angular insensitive frequency selective surfaces (FSSs) based on meander lines. The FSS element is a closed metal slot winding around over the unit cell along a self-similar pattern with a four-fold rotational symmetry. A winding index is given to characterize the total length of the meander line. The transmission peak wavelength of the FSS is approximately one-half of the total length of meander slot, which linearly scales with the winding index. For a sufficiently large winding index, where the FSS unit cell is considered a miniaturized element with the size much smaller than the resonance wavelength, the transmission peak wavelength tends to be insensitive to the angle of incidence. For the two-layered FSS embedded in the dielectrics, the transmission linewidth is also angular insensitive and much broadened for both TE and TM polarizations.