Broadside-coupled triangular split-ring-resonators for terahertz sensing

In this study, broadside-coupled triangular split-ring-resonators are designed and simulated as THz sensors. Their double-side sensing capability provides sensitivity enhancement compared with singlesided sensors. The material to be detected is modeled as an over-layer on the structure. The ensuing change of the transmission resonances is investigated as a function in the thickness and permittivity of the substrate and of the one- or two-sided over-layer. The propagation direction of the incident wave also allows to select the excited mode (via the polarization of the radiation) which provides additional flexibility to the proposed sensor device by the possibility to operate it over a larger frequency range. Overall, the polarization dependency of the structure, the double-side sensing and the high sensitivity make such structures attractive as THz sensors.