Phase-Locked Millimeter Wave Gunn Oscillators with Large Mechanical Tuning Range

A new design for millimeter-wave Gunn oscillators has been developed, yielding a mechanical tuning range of about 15 GHz (70-85 GHz) and an output power up to 16 mW. The GaAs Gunn oscillator is tuned at the fundamental frequency (Q-band) in a crossed-waveguide resonator. In addition the output frequency of the Gunn oscillator is phase-locked by an active servo loop to an atomic clock.