This document describes the ruggedness improvement of RF DMOS devices, as well as the impedance mismatch issue between the output and load of RF power transistors. A theoretical model simulating the failure mode mechanism is proposed, and relevant corrective actions are undertaken.
RF amplifiers often face impedance mismatch between the output and the load, generating reflected waves that can damage RF power transistors. While FF transistors withstand these conditions well, standard DMOS devices historically lacked the necessary ruggedness, a weakness believed to be intrinsic to their structure. This document investigates the failure mechanism under severe RF load mismatch conditions.
The device may exceed a maximum allowed junction temperature of 200 °C during certain operations.
The UIS Failure current is 10 A when there is no deep body dose.