Ionizing-radiation-induced oxide-trapped charges and interface states cause the current and 1/fnoise degradation in bipolar junction transistors. In order to better understand these two degradation mechanisms and develop hardening approaches for a specific process technology, it is necessary to measure the effect of each mechanism separately. In recent years, several techniques have been developed, but no charge-separation approach based on 1/fnoise for NPN bipolar junction transistors is available. In this...