現今電力電子元件多由矽作為主要的材料，在過去半世紀的研究中發現，矽材料已經逐漸達到物理限制瓶頸，替代矽之新材料也逐漸被發現，包含兩種或更多元素所構成之化合物，這種具有高潛力的半導體稱為「化合物半導體」，尤其以氮化鎵(GaN)電晶體發展最為成熟。與傳統矽功率元件相比，氮化鎵(GaN)具備高電子遷移率、寬能隙、高崩潰電場、低導通電阻及高飽和電子速度等優越條件。
本論文使用GaN FET實現一台操作在300kHz，輸入電壓為85~264Vac，輸出400V的500W升壓型功率因數修正器，效率最高可達97%。

Silicon is the major material of modern power electronics.In the past half century, the study found that the silicon material has gradually reached the physical limit bottleneck. New material compounded of two of more elements has gradually been found to replace silicon.This semiconductor referred to as "compound semiconductor" has a high potential, In particular, gallium nitride (GaN) transistors has the maturest development. Compared with traditional silicon power (GaN) has the adcantages such as high electron mobility, wide bandgap, high breakdown electric field, low on-resistance and high saturated electron speed.
Therefore, this thesis adopts the GaN FET to develop a 300kHz 500W boost power factor corrector with 85~264Vac input and 400V output.The measured efficiency can be up to 97%.

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