Transient analysis of the TRAPATT mode

A computer study of a TRAPATT device-circuit interaction has been performed in the time domain under various conditions of pulse rise time and current density. For a 4.3-ns rise-time pulse at 12,000 A/cm², a movie will be shown which shows the voltage on the coaxial circuit together with the carrier concentrations and electric field in the diode during the starting transient and for one TRAPATT cycle. These results are not adequately explained by existing theory which indicates that a pulse reflected from the circuit triggers the subsequent cycle. Transient and TRAPATT operation of the p⁺nn⁺and n⁺pp⁺devices will be discussed and compared.