二維週期結構之波導特性研究-微擾分析法

Abstract

本論文使用介質間之微擾觀念 (Perturbation) 來作為分析二維週期結構波導特性之基本方法。經由簡易但精確的微擾分析法，我們分析並比較了三種形式的二維週期結構(two-dimensionally dielectric periodic structures) : 分別是(1) 特殊三角陣列形式結構（2）矩形陣列形式結構 (3) 三角陣列形式結構。經由改變週期結構之參數，掃描頻率，以及不同的入射角度，我們獲得了其對應之衰減常數(attenuation constant)，幅射波束 (radiation beam) 的角度(elevation and azimuthal angle) 和相關的物理現象。此研究可廣泛用於並改善光耦合器 (optical coupler) 以及漏波天線 (leaky- wave antenna) 之設計方法與議題。

In this thesis, we present an improved perturbation analysis to analyze the characteristics of general 2D periodic structures. In particular, three types of 2-D dielectric periodic structures: Special case of triangular array pattern, Rectangular array pattern, and Triangular array pattern are presented here. The effect of various grating parameters on the attenuation constants are interpreted in terms of the Brillouin diagram. We also investigate the other phenomena by changing the frequency and angle of incident surface wave. For simplicity, we restrict the incident condition to the case of TE polarization. The case of TM incidence and some potential applications, such as leaky-wave antenna design or optical couplers, will be analyzed in the further research.