Absorption efficiency in impedance matched infrared dipole antenna-coupled microbolometers

Optical antenna collection efficiency is limited by material loss, particularly dissipation in optical metals. We investigate the radiation resistance and Ohmic resistance in transmitting infrared (IR) dipole antennas by considering the concepts of input impedance, radiation efficiency and dispersion of metals in the antenna. Then by applying antenna reciprocity, the receiving properties of IR antennas are explored. We analyze the power absorbed by a nickel (Ni) microbolometer load connected with a half-wave dipole antenna and a full-wave dipole antenna. By tuning the load impedance we are able to impedance match to IR dipoles in order to show enhanced absorption efficiency when radiation resistance dominates over Ohmic loss.