氮化鎵高電子遷移率電晶體在近幾年中逐漸發展成熟，除了穩定性提高外，更有適用於不同需求的規格可供選擇，在許多方面都比現有的矽功率開關還要有更佳的特性，得以使電路操作在更高的頻率上。
因此本文將氮化鎵電晶體使用在零電壓切換的串聯諧振電路中，以期提高切換頻，並且降低切換損。二次側方面使用同步整流開關，也可減小輸出大電流時的導通損耗。最後就是平板變壓器取代了一般使用繞線架繞製的變壓器。本論文最終實現一台操作在1MHz輸入電壓380V轉12V輸出的500W半橋串聯諧振轉換器，實驗結果經驗證後效率最高可達93%。

Gallium-nitride high-electron-mobility transistors (GaN HEMT) are gradually developed prosperously these years. Besides the more steady behavior, they are available in different specifications for various applications. GaN HEMTs outperform Si-transistors in many ways, and allow the circuit to be operated at higher switching frequency.
This thesis applies GaN HEMT transistors on a soft-switched series resonant converter in order to reduce its switching loss at higher switching frequency. Synchronous rectifier is utilized on the secondary side to minimize the conduction loss resulted from the high output current. In addition, a planar transformer takes the place of the usually applied winding transformer. A half-bridge series resonant converter operated at 1 MHz is implemented to perform the conversion of 380 V to 12V with rated power of 500 W. The experimental results show that the power efficiency can be as high as 93%.

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