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標題: 高溫超導微波元件設計
Design of high-temperature-superconductor microwave devices
作者: 施冠州
Shih, Kuan Chou
關鍵字: high-temperature superconductor
fault current limiter
switching time
protecting module
出版社: 物理學系
摘要: 摘要 本研究是利用高溫超導材料(YBCO)薄膜設計微波元件:(1)故障電流限流器( fault current limiters),設計的原理,是利用突然受到一超過臨界電流Jc ( critical current)的大電流(錯誤電流fault current)通過與電路串聯的 YBCO,使得YBCO瞬間會由零電阻的超導(SC)態轉換成高阻抗的正常(NM)態,藉此限制通過的電流。當錯誤電流消失,材料恢復超導(SC)態,系統恢復正常運作。保護的電路範圍除一般電源系統外,我們更推廣到高頻系統,如通訊用天線及雷達天線。(2)溝槽線圓共振器( slotline ring resonator),設計原理是利用一封閉圓形溝槽線,建立任一個奇數倍或偶數倍的駐波波長形成共振,我們設計了一個10GHz的圓形溝槽線共振器,利用共平面波導(coplanar waveguide)將訊號耦合進入共振器,當輸入訊號頻率是10GHz或是10GHz的正整數倍時,會在圓形溝槽線形成共振。
Abstract In this thesis, we use high temperature superconducting (HTSC) materials to design microwave devices, including (1) fault current limiters and (2) slotline ring resonator. (1) Fault current limiters can survive under very fast high-current pulses. This device, due to its potential high-speed characteristics, can not only be used in ordinary power systems, but also incorporated in antenna or radar systems. While a huge current (larger than the critical current Jc) pulse is forced to run through a superconducting (SC) material, the material will suddenly undergo a phase transition from a SC state to a normal metallic (NM) state, and the resistance will rise rapidly. Thus the fault current will be limited. A shunt path with a resistance lower than that of the NM state can further provide a bypass for the fault current to increase the current handling capability. Once the fault condition disappears, the material switches back to the SC state, and the system recovers to the normal operation condition. (2) We have designed a slotline ring resonator with a resonance frequency at 10GHz. The CPW coupling is formed by a small coupling gap between the external CPW feed lines and the slotline ring.
Appears in Collections:物理學系所



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