Alumina, broadband, carbon nanotubes, coaxial discontinuities, complex permittivity measurements, mode matching technique, nano-particles, radio frequency
Electrical and Computer Engineering | Engineering
This work presents a comprehensive characterization of the frequency dependence of the effective complex permittivity of bundled carbon nanotubes considering different densities over a broadband of frequencies from 10 MHz to 50 GHz using only one measurement setup. The extraction technique is based on rigorous modeling of coaxial and circular discontinuities using mode matching technique in conjunction with inverse optimization method to map the simulated scattering parameters to those measured by vector network analyzer. The dramatic values of complex permittivity obtained at low frequencies are physically explained by the percolation theory. The effective permittivity of a mixture of nano-particles of alumina and carbon nanotubes versus frequency and packing density is studied to verify the previously obtained phenomenon.
E. Decrossas, M. A. El Sabbagh, V. F. Hanna, and S. M. El-Ghazaly, "Rigorous Characterization of Carbon Nanotube Complex Permittivity Over a Broadband of RF Frequencies," Ieee Transactions on Electromagnetic Compatibility, vol. 54, pp. 81-87, Feb 2012.