Measurement and simulation of the sensitivity of terahertz frequency range passive flter elements to overlaid dielectrics

Resonant terahertz filters in microstrip lines have been proposed as devices suitable for the detection of the properties of overlaid dielectric materials, with potential applications including the on-chip assay of DNA and other biological molecules. Here, we provide a direct comparison of numerical simulations to calibrated experimental data obtained on our resonant structures. We employ two different codes (HFSS and Sonnet) to cross-check the results of our numerical simulations, and conclude that stub-based THz band-stop filters offer an improvement in sensitivity (of order 100x) per unit active area compared with alternative designs. This is a result of the enhanced THz electric field concentration in the overlaid dielectric which this particular geometry produces.