Cutoff frequency of substrate integrated waveguide with single-walled carbon nanotube bundle vias

Carbon nanotubes have many unique properties, which are very suitable for the small-scale and high-frequency applications. The terahertz substrate integrated waveguide (SIW) built with single-walled carbon nanotube (SWCNT) bundle vias is analyzed here. The input impedance of a single SWCNT via in array can be effectively calculated using our proposed circuit model, which is further applied to find the cutoff frequency of SIW. Good agreement is achieved between the results of our model and full-wave simulations. The impacts of tube diameter and volume filling factor on the cutoff frequency are studied. The results are also compared with that of the SIW with Cu vias.