60 GHZ SOURCES USING OPTICALLY DRIVEN HETEROJUNCTION BIPOLAR-TRANSISTORS

Millimeter wave sources at 60 GHz have been demonstrated using optically driven heterojunction bipolar transistors configured as photodetectors. Two techniques were used to optically generate the millimeter waves; the mixing of two cw lasers and the mode locking of a semiconductor laser. The millimeter wave power generated from these two configurations was radiated into free space using integrated planar twin-dipole antennas and heterodyne detected with signal-to-noise ratios >40 dB. As part of these experiments, the dc optical gains and quantum efficiencies of the heterojunction bipolar transistor photodetectors were determined.