Abstract :
Current and voltage waveforms of the Si IMPATT diode were observed directly by means of the oscillating circuit using microstrip line. The results indicate that the conventional small-signal theory cannot be applied to the observed type of oscillation. The oscillation starts at the bias voltage just above the breakdon voltage of the diode; then along with its buildup, the bias voltage is lowered owing to the auto-bias effect, to reach a steady value considerably below the breakdown voltage. Large amplitude oscillation of high efficiency is expected over a wide frequency range.
