A novel dual-band frequency selective surface (FSS)

A single-layer frequency selective surface (FSS) is developed with electrically small elements and two tunable passbands for WLAN application. Each FSS unit consists of a loop wire in the top metal layer and its complementary etched in the bottom metal layer, which can provide two transmission poles separated by a transmission zero. The structure is optimized so as to meet the specification of miniaturization and required passbands. An equivalent circuit model is also presented for predicting the frequency selective characteristics of the designed FSS, which is validated by the simulated and measured S-parameters with good agreement obtained between them.