Lower Frequency Limit of Carbon Nanotube Antenna

Carbon nanotubes are characterized by slow wave propagation and high characteristic impedance due to the additional kinetic inductive effect. This slow wave property can be used to introduce resonant dipole antennas with dimensions much smaller than traditional half-wavelength dipole in Terahertz band. However, this property has less effect at lower frequency bands. This paper introduces the physical interpretation of this property based on the relation between the resonance frequency and the surface wave propagation constant on a carbon nanotube. This surface wave propagation is found to be characterized by high attenuation coefficient at low frequency bands which limits using carbon nanotube as an antenna structure at these frequencies.