W-Band GaN IMPATT Diodes for High Power Millimeter-Wave Generation

The DC and large signal characteristics of a GaN IMPATT diode designed for operation at W-band are investigated using Sentaurus TCAD simulations. The impact ionization model for GaN is calibrated using measured impact ionization coefficients of both electrons and holes, and both field- and carrier-concentration dependent velocity-field relationships are considered for accurate simulation. Large signal simulation results show that the IMPATT diode design evaluated is capable of generating an output RF power larger than 1 MW/cm² from 80 GHz to 120 GHz with an efficiency larger than 18%.