Electronically switchable and tunable bandpass filters based on spoof localized surface plasmons

Abstract

Through directly manipulating spoof plasmonic particles, electronically switchable and tunable bandpass filters have been proposed and experimentally demonstrated in the microwave frequency. The propagation of spoof localized surface plasmons (LSPs) can be controlled by use of double slits in a corrugated ring. The passbands of the filter can be switched on and off by mounting Schottky barrier diodes across the slits. The frequency spectrum of the passbands can be electronically tunable by adjusting the applied bias voltage across the varactor diode. Both simulated and measured results demonstrate dynamic transmission of spoof LSPs in bandpass filters in microwave frequencies. Such electronically controlled devices could find many applications in plasmonic integrated functional circuits.