A Tunable Spoof surface plasmon polaritons Waveguide with Switchable Passbands

In this paper, spoof surface plasmon polaritons (SSPPs) which are supported by periodic unit cells formed by metallic stubs loaded with PIN diodes are proposed. Dispersion properties of SSPPs with a diode in both on and off states are analyzed. The SSPP waveguide constructed by the proposed unit cells is designed and simulated. The switching between single pass band and double pass band can be realized by using the two different states of the PIN diodes. The simulated passband with a return loss higher than 10 dB ranges from 2.91 to 10.24 GHz, while the stopband with a rejection level better than -20 dB is from 3.95 to 5.51 GHz. It is shown that the feasibility of the proposed strategy to design a tunable SSPP waveguide based on PIN diodes, constitutes an important step toward the realization of reconfigurable spoof plasmonic metamaterials.