1Radiation Efciency of Nanoradius Dipole Antennas in the Microwave and Far-Infrared Regime

AbstractAt microwave and far-infrared frequencies, the radiation efciency of a wire antenna with radius values smaller than a few hundred nanometers is very low, due to large wire impedances and associated high ohmic losses. However, with the continued miniaturization of electronic devices, nanoradius interconnects and antennas are desirable. In this work, the relationship between wire radius, conductivity, frequency, and ohmic loss is examined for dipole antennas. Simple formulas are derived for the distributed resistance, effective conductivity, and radius required to achieve a desired radiation efciency, and particular emphasis is given to half-wavelength antennas. Several methods to improve antenna efciency at sub-100 nm radius values are discussed, including the use of superconducting nanowires and multi-wall carbon nanotubes. Index Termsnanoantenna, nanotechnology, carbon nanotube I