開口式共振腔之特性與研究

Abstract

論文的主要內容圍繞著開口式共振腔，開口式共振腔可以有效率地取出電子束所產生的電磁場，因此常常被應用於磁旋震盪管和磁旋調速管中。在電子束通過其開口端的期間，開口式共振腔將可獲得來自電子所產生的電磁場。由於開口式共振腔和閉口式共振腔的不同在於其無明顯的邊界，因此大部分的情況沒有解析解。我們僅能用程式模擬出數據並且分析，來深入了解其物理性質及意義。 本文中將會由頻域及時域基本模型結構出發，並介紹其理論與數學。在時域模型中將探討其各種變因對共振頻率以及品質因子的影響。而在頻域模型中將介紹3種量測方法。並且探討品質因子在時域以及頻域之下的差別。 此外我們也將在開口式共振腔後端加入不匹配附載來觀察其對品質因子與共振頻率之影響 最後我將模擬新的結構，對其數值模擬作分析並給出合理的物理解釋。

The main content of this thesis around open cavity, open cavity can effectively extract out the EM field which is caused by electron beam. Open cavity is commonly used in gyromonotron oscillator and gyroklystron amplifier. Open cavity gain energy during the electron beam pass the cavity. Because the open cavity doesn’t have obvious bound, we don’t have analytical solution most of the time. We can only use program to have data and analysis it to understand its physical meaning. In this thesis we will introduce the model and theory of time-domain and spectral-domain. In time-domain, I discuss how variables affect the Quality factor and resonant frequency. In spectral-domain, I introduce 3 methods to measure the Quality factor. And I compare the difference between Quality factor in time-domain and spectral-domain. Besides, we also add a mismatch load to observe how it affect Quality factor and resonant frequency. Finally, I will simulate a new structure of open cavity. And give it a reasonable explanation.