A Tunable Bandpass Frequency-Selective Surface with High Selectivity

A tunable bandpass frequency-selective surface (FSS) with high selectivity is presented in this article. The FSS structure is composed of four stacked metallic layers and loaded with eight varactors. The metal structures in each layer are connected by metal vias to provide bias for the varactors. This configuration realizes the fusion of bias network and FSS structure. Simulation results show that by changing the varactor capacitance from 0.1 to 0.6 pF, the center frequency of the passband is moved from 6.27 to 12.27 GHz. In the frequency tuning range, the rectangle coefficient (RC) value of the FSS structure is less than 0.27.