Millimeter wave (220 GHz–330 GHz) characterizations of carbon nanotube films

A carbon nanotube (CNT) film on a substrate is characterized at millimeter waves (220 GHz−330 GHz) by metal rectangular waveguide scattering parameters (S-parameters) measurements. The anisotropy of the CNT film is investigated for different orientations of the on-substrate CNT film. The standard Nicolson–Ross–Weir (NRW) approach has been adopted to extract the complex permittivity (er=e′-je″) and permeability (μr=μ′-jμ″) of the on-substrate CNT film from the measured S-parameters. The effective medium theory is then applied to remove the impact of the substrate and characterize the intrinsic CNT film. The observed frequency independent and anisotropic behaviors of the CNT film are very promising indicators that this material could be invaluable for a range of millimeter-wave applications.