Multifunctional Spoof Plasmonic Transmission Line with Dynamically Switchable Modes

A multifunctional transmission line (TL) based on spoof surface plasmon polaritons (SSPPs) is proposed for dynamical switching features among bandpass, band-stop, and dual-band phase shifting functionalities. Different operating modes can be controlled in real-time by changing the states of the Positive Intrinsic Negative (PIN) diodes synchronously. The dispersion properties of the spoof plasmonic unit cell and transmission characteristics of the tunable PIN-diodes-loaded spoof plasmonic TL are investigated to highlight the basic theory and method. A prototype of the proposed TL composed of five cascaded unit cells is fabricated and tested for proof-of-concept validation. In the ON state of the PIN diodes, the measured -3 dB transmission frequency bandwidth ranges from 3 to 8.1 GHz for the bandpass characteristic. In the OFF state, the measured -10 dB rejection band spans from 3.7 to 5.6 GHz for the bandstop characteristic. When the diodes are switched between ON and OFF states, the measured dual-band phase shifts vary from 192 degrees to 203 degrees and 248 degrees to 292 degrees in the 3.1-3.4 GHz and 6.1-9.4 GHz frequency bands, respectively. The validated switchable features of the TL pave the way for applications of tunable SSPPs in large-scale integrated circuits and smart wireless communication systems. A multifunctional transmission line (TL) based on spoof surface plasmon polaritons (SSPPs) is proposed for dynamical switching features among bandpass, band-stop, and dual-band phase shifting functionalities. The validated switchable features of the proposed plasmonic TL pave the way for applications of tunable SSPPs in large-scale integrated circuits and smart wireless communication systems.image