Indirect optically injection-locked oscillator for millimeter-wave communication system

A millimeter-wave optically injection-locked oscillator has been designed and fabricated. It represents the first millimeter-wave hybrid transistor oscillator locked to a long-wavelength optical signal. The oscillator could be used as a photoreceiver in remote base stations in future picocellular communication systems employing fiber-optic backbones; its high "gain" (output relative to input locking signal) and relative flatness in output power may make it attractive compared to simple millimeter-wave amplifier configurations. Measurement results show the output signal exhibits little variation (less than 0.7 dB) with input optical power changes of 6 dB. A locking bandwidth of 2.6 MHz has also been achieved.