Study Of Carbon Nanotube Antenna Effect

Carbon nanotube as antennas have expansive prospect of application, because of the small size, light weight and good electronic properties. For example, it can be used in the fields of optic fiber communication, wireless inter-connection to nanosystems, THz and infrared detectors, solar energy conversion and so on.In this paper, based on the computer simulation and theoretic study, the capabilities of carbon nanotube antennas in the wave band of THz and visible light have been investigated. A model of carbon nanotube antenna has been simulated by CST Microwave Studio. The simulation results agree with the experimental results.Using CST Microwaves Studio, the THz carbon nanotube antenna has been proposed and simulated for the single and array antenna, the structure of carbon nanotube, included the diameter, length, and inter-tube distance would affect its capabilities. To increase the gain should increase density of the nanotubes arrays, and an appropriate inter-tube distance, mean while control the length of carbon nanotube array. The diameter of each array elements has little effect to the gain of carbon nanotube antenna arrays.In the visible light wave band, a carbon nanaotube antenna has be regarded as a center fed antenna which was been formed by two transmission line with terminal open circuit. Based on the classic transmission line theory, the function of current distribution and re-radiation pattern of carbon nanotube with different incidence angleΦhave been obtained by theoretic study. The re-radiation pattern with different incidence angleΦhas been simulated by CST Microwave Studio. The theory and simulation results agree with the experimental results which have been proved by others. When the length of carbon nanotube antenna is as several times as wavelength of incidence wave, the main lobe direction of re-radiation pattern should be varied with the incidence angleΦ, and the strongest radiation should be at the angle of reflection(180°-Φ). The lobe density of re-radiation pattern should be increased with the increase of carbon nanotubes'length, and the lobe density of re-radiation should be decreased with the increase of carbon nanotube antenna arrays'inter-tube distance.