Design, Performance, and Behavior of Pulsed and CW Silicon Double-Drift Impatts

Double-drift silicon IMPATTs for high power pulsed and CW applications have been optimized by the proper design of the width and impurity concentration in both the N and P-layers. Peak pulse powers greater than 18 watts at a 25% duty cycle were obtained at 10 GHz with the junction temperature rise limited to 200°C. For similar temperature rises CW powers of 3.4 watts at 11.5 GHz and 4.2 watts at 8.5 GHz were achieved. Conversion efficiencies were between 10.5 and 13.7%. Some detailed measurements of the large-signal conductance and FM noise of the CW devices are presented.