中心帶線寬度具週期變化之共面波導結構

Abstract

本篇論文主要是利用簡單、快速且可靠的有效界電常數方法來分析兩種類型之週期變化共面波導結構：分別是中心帶線與基板介質具週期變化的結構。我們首先計算無窮週期結構之色散特徵解，並以熟知之布理林圖來呈現，以掌握其通禁帶之分布行為。另一方面，我們亦考慮有限長度週期結構之波導波模散射問題，藉由數值模擬與實驗量測其傳輸參數來與色散關係圖做交叉相互驗證，並獲得相當一致的結果。在本篇論文中我們利用簡單的圖解法配合波模耦合理論解釋色散關係中通禁帶之物理現象，除了建立波於該週期結構中傳播之物理圖像之外，更能夠提供工程設計法則以作為電路設計之參考依據。

In this thesis, a simple, efficient yet accurate method based on the Effective Dielectric Constant (EDC) was developed to analyze the coplanar waveguide with periodic variation. The structures considered here contain two types: one is the periodic variation in strip width and the other is that of in the substrate. The dispersion characteristics including the phase and attenuation constants both are displayed in the form of the Brillouin diagram. In addition, the distributions of stopband are verified by measured data. Thus, the method in this thesis provides not only a clear physical picture for understanding the wave phenomena involved but also a simple and accurate design criterion for practical considerations.