Yee於西元1966年所提出的Finite Difference Time Domain Method(有限時域差分法)是近年來相當熱門的數值方法。FDTD是從Maxwell`s Equations 所推導得出，可應用於不同問題，例如天線模擬、微波電路設計及電磁相容等問題，且擁有強大計算能力的全波分析法。本論文主要是利用FDTD來模擬共面波導(Coplanar Waveguide)電路—應用於MMIC傳輸線的電路。分析CPW電路時，由於CPW複雜的邊界條件，因而加深了分析的困難度，然而FDTD是透過簡單的Maxwell`s Equations描述其介質特性，因此可輕易分析CPW電路。即便如此，在分析的過程中，還是易因CPW色散的特性及鬆散的電場分布提升分析的困難度。因此，本論文便使用不同激發方式及吸收邊界探究如何方可有效地分析CPW電路，最後再直接模擬CPW天線與轉接電路以驗證其結果；至於天線場型的計算方面，則使用遠場轉換計算天線場型，其優點在於遠場轉換不受天線形狀限制，任一天線皆可由FDTD計算得出，且遠場轉換不只可應用於天線設計，也可使用於EMC的量測與分析。

In this paper,we used Finite-Difference Time-Domain Method to Analyze CPW and Antenna.In CPW
,we had to process excitiation source and ABC.Or we couldn`t get correct result.In antenna analysis,we used KSIR to calculate antenna pattern.

目錄 I
圖表目錄 III
第一章 序論 1
1.1 研究背景 1
1.2 研究目的 1
1.3 論文大綱 2
第二章 時域有限差分法的原理 3
2.1 FDTD的演算法 3
2.1.1 Yee的FDTD演算法 3
2.1.2穩定準則的處理 6
2.2激發源的處理 9
2.3吸收邊界(Absorbing Boundary Condition)的處理 11
2.3.1 Mur一階吸收邊界 12
2.3.2 Mur二階吸收邊界 12
2.3.3 DBC(Dispersion Boundary Condition)吸收邊界 13
2.4 Berenger’s PML完美吸收層 16
2.4.1自由空間的3-D PML 16
2.4.2非均勻介質的3-D PML 20
第三章 運用FDTD分析共面波導結構 24
3.1序論 24
3.2共面波導激發源的處理方式 24
3.3吸收邊界之比較 27
3.4 CPW-Fed Folded-Slot Antenna的分析 30
3.4.1 Folded Slot Antenna的結構 30
3.4.2模擬結構及參數計算方法 31
3.4.3三種不同吸收邊界分析Folded Slot Antenna 32
3.4.4數據結果分析 35
3.5使用PML分析CPW to Slotline Transition 36
3.5.1 CPW to Slotline Transition的結構 36
3.5.2以FDTD分析CPW to Slotline Transition 37
3.5.3計算數據結果 39
第四章 近場-遠場轉換 42
4.1序論 42
4.2表面等效定理 42
4.2.1等效定理原理 42
4.2.2遠場電磁場計算 43
4.3以克希荷夫表面積分公式(KSIR)作遠場轉換 45
4.3.1克希荷夫表面積分公式 45
4.3.2 KSIR的遠場轉換離散化 46
4.3.3 KSIR積分面的修正 49
4.4計算基本電偶極的E-plane pattern 51
4.4.1模擬結構簡介 51
4.4.2數據結果 52
4.5 Patch Antenna的場型計算 53
4.5.1以Cavity Model計算場型 53
4.5.2數據結果比較 55
4.6 CPW-Fed Folded Slot Antenna之場型計算 57
4.6.1模擬結構簡介 57
4.6.2 計算數據結果 57
第五章 結論 59
附錄A 克希荷夫表面積分公式推導 60
附錄B 克希荷夫表面積分公式離散化推導 63
參考文獻 64

參考文獻

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