An ultra‐thin frequency‐selective surface with inductive loading for X‐band shielding applications

Summary

A novel band‐stop frequency‐selective surface (FSS) for X‐band electromagnetic shielding is reported in this study. The single‐layer, single‐sided FSS has frequency‐dependent conductive patterns developed on a polyimide substrate that provides strong rejection to the entire X‐band frequencies. The unit cell FSS has an octagonal loop configuration. Each side of the octagonal loop is alternatively loaded with thick conductive patches and stub lines to reject 8 − 12 GHz with |S₂₁| ≤ −15 dB. The size of the unit cell FSS is 0.167λ_o × 0.1673λ_o where λ_o is the free space wavelength calculated at the center frequency. Owing to the rotational symmetry, the FSS unit cell exhibits mode‐independent characteristics. The bending characteristics of the FSS are analyzed, and the inferences show that the FSS properties remain unchanged under flat and bent cases. The ultra‐thin FSS offers stable frequency response for normal and oblique incidences up to 80°. The designed FSS is fabricated and tested under laboratory conditions to validate the simulation results.