GaN-based NDR Devices for THz Generation

GaN-based Negative Differential Resistance (NDR) diode oscillators have been studied by employing Gunn design criteria applicable to this material system. Numerical simulations were used to carry out large-signal analysis of the GaN NDR diode oscillators in order to evaluate their potential for THz signal generation. It was found that, due to the higher electron velocity and reduced time constants involved in the diode operation, GaN NDR diodes offer significantly higher frequency and power capability than conventional GaAs Gunn diodes. Based on the performed analysis, THz signal generation using GaN-based NDR diodes was predicted. GaN NDR layer structures were grown by MOCVD. The fabrication technology and characterization techniques used for GaN NDR diode oscillators are presented.