Variable Operating Frequencies Spoof SPP Filter Based on Double-Layers Structure

A novel variable operating frequencies spoof surface plasmon polariton (SPP) filter is proposed in this letter. This proposed spoof SPP filter is adopted double-layers structure, the bandwidths of this proposed filter can be freely designed by loading corresponded upper layer. Dielectric layer and I-shape structure layer are utilized to design the upper layer of the proposed filter, then, wide-range continuous variable operating frequencies spoof SPP filter is achieved. The cut-off frequency of this filter can continuously shift from 2.40GHz to 11.35GHz when corresponding I-shape structure layers are designed. Both simulation and experiment results verify our design. This wide-range continuous variable operating frequencies spoof SPP filter presents the improvement and convenience in practice applications.