Modelling of the Effective Dielectric Constant of Corrugated Planar Goubau Lines for Terahertz Band

We present the modelling of effective dielectric constant of Corrugated Planar Goubau Lines (CPGL), which can support spoof Surface Plasmon Polaritons (sSPP) at terahertz band. The model proposes an empirical formulation of the effective dielectric constant as a function of CPGL dimensions, namely corrugation depth, aperture, and periodicity, in combination with the dielectric constant and thickness of the substrate. We then verified the model over a wide range of CPGL corrugation depths using finite element simulations, and we achieved an effective dielectric constant error better than 5% and 7% at 250 and 275 GHz, respectively.