Stability of wireless power transfer using gamma-ray irradiated GaN power HEMTs

In this work, we have demonstrated the wireless power transfer (WPT) system based on the pristine and irradiated E-mode GaN devices. The GaN device has been irradiated up to the 100 kGy dose under the γ-ray irradiation, showing the improved electrical characteristic, such as the drain current increase (~8.34%) and gate current decrease (~−7.79%). An off-state drain induced instability measurement shows the robust performance in pristine and irradiated GaN device. Noted that the irradiated device exhibits less ΔV_TH, suggesting the device instability has been improved. Moreover, the wireless power transfer efficiency was evaluated by utilizing different load (20 Ω ~ 120 Ω) at V_DS = 50 V and V_GS = 4 V. The results indicate that the transfer efficiency of WPT by implementing the pristine and irradiated GaN device are similar. Furthermore, the output power of WPT using the irradiated GaN device becomes higher, which is mainly due to the improved drain current in irradiated GaN power devices.