X-band characterization of multi-walled carbon nanotube films

A vertically aligned multi-walled carbon nanotube (VACNT) film has been characterized by rectangular waveguide measurements. The complex scattering parameters (S-parameters) are measured by a vector network analyzer at X-band frequencies. The effective complex permittivity and permeability of the VACNT film have been extracted using the Nicolson-Ross-Weir (NWR) approach. The extracted parameters are verified by full wave simulations (CST - Microwave Studio) and very good agreement has been obtained. The performance of VACNT films as an absorber is examined, and comparison with the conventional carbon loaded materials shows that a 90% size reduction is possible whilst maintaining the same absorption level.