Design of coplanar terahertz spoof surface plasmonic waveguide and its application in low pass filter

In this work, a coplanar terahertz plasmonic waveguide (CTPW) based on spoof surface plasmons (SSP) with grooved ground and signal strip is proposed. The confinement and the propagation of terahertz (THz) signal can easily be controlled by tuning the geometrical parameters of the grooved T-shaped SSP cells. The asymptotic frequency of the grooved T-shaped SSP unit cell basically restrict the THz signal propagation beyond this point and hence, it might act as a high cutoff frequency point for the designed waveguide, which can be used for low pass filter applications. The proposed idea of coplanar plasmonic waveguide is experimentally validated in microwave frequency region by scaling up the geometries of the proposed corrugated CTPW line, which are in good agreement with its simulated counterpart.