Frequency-Independent RC Circuit Model for One-Dimensional Carbon Nanostructures

We demonstrate that a frequency-independent parallel RC circuit is the simplest model that accurately describes high-frequency electrical conduction in 1-D nanostructures. The resistance is determined from dc measurement, and the capacitance is extracted directly from the measured S-parameters for a ground–signal–ground test structure, without using any fitting parameter. The methodology is applied to carbon nanofibers, and the RC model yields results that are within ±0.5 dB and ±5◦ of the measured S-parameters up to 50 GHz. The model is further justified by examining the relationship between Sand Y -parameters of the test network.