A High Power 50GHz DDR IMPATT Oscillator with Low Side Band Noise

Low-frequency instabilities in millimeter-wave Double-Drift-Region (DDR) IMPATT diodes are investigated and the oscillator circuit which suppresses low-frequency instabilities is developed. DDR IMPATT mounted in this circuit exhibited output powers 1.6W at 55.5 GHz with 11.5 percent efficiencies.