差模傳輸對已有逐漸取代單一訊號線在高速數位電路中傳遞高頻訊號的趨勢。本篇論文主要是研究差模傳輸對在高速電路板上其訊號線間距大小以及邊緣效應對電磁輻射的影響。我們同時以量測與模擬比對結果來說明量測方法的準確。結果顯示，間距愈小對差模傳輸對愈有抑制EMI的效果。而邊緣效應會影響差模對抑制EMI的能力。
基於量測準確性的考量，我們在開始探討差模對對EMI的影響前，使用一仔細嚴謹的量測方法，找出實際量測與理想模擬之間的不理想效應，以期望對真實量測環境的掌握。
此外，我們提出一種簡單、快速探討差模對邊緣效應輻射機制的方法。以此方法來計算差模對輻射，可使我們對輻射機制有更多了解。

Differential pairs may gradually replace single trace as the media transmitting high-speed signal on high-speed digital circuit. This dissertation investigates the impact on electromagnetic radiation from high-speed circuit board by the distance between differential traces and edge effect .At the same time, we use the result of measurement and simulation to make sure the measurement method correct .The result shows that,the shorter the distance is,the lower the EMI of differential pairs have .The edge effect will has the ability of destroying the suppression of EMI.
Based on the consideration of measuring correctly, we use a solid kind of measurement method to search some non-ideal effects before studying EMI from differential pairs .These effect may exist on real measurement or ideal simulation. We hope to understand the environment of measurement as clearly as possible.
In addition, we address one simple and fast method to investigate radiation mechanism that resulted from edge effect of differential pairs.By this method to calculate radiation, we will understand more and more the radiation mechanism.

誌謝 i
論文提要 ii
目錄 iv
圖表目錄 vi
第一章 緒論 1
1.1 簡介與研究動機 1
1.2 論文大綱 1
第二章 FDTD演算法 3
2.1 從馬克斯威爾方程式到FDTD演算法 3
2.1.1 三維方程式 3
2.1.2 中央差分與Yee演算法 3
2.2 數值穩定 7
2.3 介質處理 7
2.4 波源條件 7
2.5 吸收邊界條件 8
2.5.1 完美匹配層吸收邊界 8
2.5.2 非分離場完美匹配層 12
2.6 近場與遠場轉換 14
2.7 集總元件 18
2.7.1 FDTD演算法延伸至電路元件 18
2.7.2 電阻 19
2.7.3 阻抗性電壓源 19
2.8 電腦演算法與FDTD方法 20
2.8.1 前置過程 20
2.8.2 進行時間步階 20
2.8.3 紀錄場值 20
第三章 方位量測法 22
3.1 研究背景 22
3.2 方位量測法 22
3.3 量測方法 23
3.3.1 實體量測設備架設與校正 23
3.3.2 方位量測 24
3.4 模擬方法 26
3.5 模擬與量測結果 27
3.6 結論 33
第四章 差模對在PCB中對電磁輻射的效應 34
4.1 研究背景 34
4.2 差模傳輸原理 34
4.3 輻射型輻射 36
4.4 差模對設計結構 37
4.5 模擬與量測方法 38
4.5.1模擬方法 38
4.5.2量測環境及方法 39
4.6差動對對電磁輻射的影響 42
4.7 結論 51
第五章 差模對在PCB上的邊緣效應 52
5.1 研究背景 52
5.2 邊緣效應 52
5.3 設計結構 54
5.4 量測與模擬方式 55
5.4.1 模擬方式 55
5.4.2 量測方式 55
5.5 探討邊緣效應對差動對的影響 56
5.5.1驗證模擬與量測 56
5.5.2探討在不同邊緣位置之差模對的輻射影響 56
5.5.3探討在相同邊緣位置之差模對的輻射影響 57
5.5.4以場型來探討邊緣對差模對的輻射影響 57
5.6結論 66
第六章 以一維方程探討邊緣效應機制 67
6.1 研究背景 67
6.2 共模電感 68
6.3 等效模擬化估測遠場輻射 70
6.4 邊緣效應探討 73
6.5 結論 82
第七章 結論 83

參考文獻 84

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