This study compared the pre- and post-total ionizing dose (TID) characteristics of GaAs-based inductor, ELC capacitor, resistor, and pHEMT under 25, 100, and 300 krad irradiation. The inductor exhibited the highest stability with an inductance variation within 2 %. The ELC capacitor exhibited the greatest sensitivity, with the effective capacitance increasing by more than 50 %, while the ESR remained small, indicating that the TID mainly caused matching-frequency shifts driven by capacitance changes. Both the resistor types exhibited a variation of >3 %. The pHEMT exhibited a 1~10% drain-current variation depending on the bias, and at 300 krad, a non-monotonic behavior was observed, where ID increased under specific bias conditions. These results indicated that the limited variation observed in the small-area pHEMT (4×50 μm) reflected its device size; larger power amplifier devices are expected to experience more pronounced TID-induced current degradation.
Kim et al. (Sun,) studied this question.