Controllable filtering structure using magnetic coupling between spoof plasmonic waveguide and solid dielectric resonators

Abstract

The structure and electrical characteristics of a dielectric resonator (abbreviated as DR hereafter) loaded plasmonic waveguide with controllable bandwidth are investigated in the present research. By loading the high permittivity dielectric medium on a spoof surface plasmonic waveguide, the working bandwidth of the filtering structure can be regulated flexibly due to the resonant effect of the loaded cylindrical DR. The DR is home-made and possesses the permittivity of 25.66, tan δ of 5.3 × 10-5 and stable temperature coefficient of -6.3 ppm/°C in microwave region. After the DR is loaded, the filtering structure can form the transmission zero on the edge of the pass band, regulating the bandwidth as well as increasing the out-of-band rejection. By controlling the height between the loaded DR and the substrate, or adjusting the inter-distance between the DRs, the relative bandwidth of the filtering structure can be effectively tailored.