A nanotube antenna is a device consisting of a carbon nanotube (a long, cylindrical carbon structure consisting of hexagonal graphite molecules attached at the edges) configured to transmit or receive electromagnetic fields (EM field s) at extremely short wavelength s. Nanotube antenna s measure approximately 50 nanometer s (nm) in diameter and 200 to 1000 nm in length. A nanometer is a unit of linear measure equivalent to 0.000000001 meter (m) or 10 ^-9 m. Nanotubes have been suggested as building blocks for the construction of nanoscale (extremely small) resistors, capacitors, inductors, diodes, transistors, and memory chips. Because of their inherent inductance and capacitance at extremely high frequencies, nanotubes may also serve as antennas at infrared (IR) and visible light wavelengths. Suggested applications of nanotube antennas, which are expected to become available around the year 2008, include photovoltaics (the conversion of sunlight to electrical energy), fiber optic communications, and high-speed optical computer s