Transmission manipulation of spoof surface plasmon polariton waveguide via GST resonators

We present a transmission-controllable spoof surface plasmon polariton (SSPP) waveguide by integrating resonators composed of the phase-change material Ge2Sb2Te5 (GST). Due to the field enhancement, the SSPP waveguide is sensitive to the local metallic structure, and the controllable transmission property is achieved by using the SSPP waveguide to excite the resonance of the spoof localized surface plasmon (SLSP) unit composed of GST. The transmission characteristics of the SSPP can be dynamically manipulated by the switchable resonance in the SLSP, owing to the electric conductivity change during the phase-change process of GST. We have simulated the transmission properties of the SSPP waveguide when the GST undergoes an amorphous-to-crystalline phase change. The simulation results show that the SSPP waveguide has a notch frequency of 7.45 GHz with a transmission dip of up to -23 dB. The proposed transmission-controllable SSPP structure has important potential in designing and developing over-temperature protection circuits and systems.