A new concept for high-efficiency operation of high-low-type GaAs IMPATT diodes

A new operation mode, the "surfing mode," is proposed as an explanation for the high-efficiency operation of high-low-type GaAs IMPATT diodes. This mode is characterized by the concept that the avalanche charge pulse drifts synchronously with the movement of the front edge of the depletion layer at a velocity higher than the saturation velocity. The design chart of high-low-type GaAs IMPATT diodes is determined on the basis of the concept of the "surfing mode." The high-low-type GaAs IMPATT diodes designed using this chart exhibited output powers of 15.3 W (\Delta T_{j}= 210°C) at 6.1 GHz with 25-percent efficiency.