在本篇論文中，我們介紹一具有負介電常數及負導磁係數之左手材料，並且利用其可聚集電磁波特性，達到可增加天線增益之效果。
一開始將分析左手材料之不同於右手材料的電磁特性，尤其是其負折射係數；其中會有具有單一負介電常數或導磁係數之結構之分析。再來，我們所設計的左手材料的確可以減少對天線反射係數的的影響，即使在天線結合了左手材料天線罩之後也是一樣的；而左手材料之單一晶胞則是利用基本單負結構結合，達到在3.5 GHz其折射率為負且趨於零之單一晶胞；我們更進一步合左手材料與天線，經過模擬分析以及實作量測，皆可發現我們設計的結構是相當有效的，天線的反射係數再結合左手材料幾乎沒有發生頻飄，且天線束徑寬明顯變窄，而在增益增加量更可達到3dB或者更高。
最後，我們成功的將左手材料縮小化，縮小的幅度可達到50% 以上，並且佐以模擬分析以及實作量測，可發現仍然保有原本之特性；此外，使用一偶極天線來驗證，並且天線增益也有增加以及天線反射係數並無太大改變。

In this thesis, we introduce a LHM (Left-Handed Material) with both negative permittivity and permeability. Improvement of gain antenna is achieved by utilizing the characteristics of the LHM which can focus the EM wave.
We start with an analysis of electromagnetic characteristic of LHM, especially its negative index of refraction. Structures with only negative permittivity or negative permeability are also analyzed. Then, we design the structure of LHM that can reduce the sensitivity of S11 of an antenna. So that the antenna operating frequency is not changed even in the presence of the LHM. The LHM unit cell structure comes from the idea by combination of two basic SNG (Single Negative) structure. We design a unit cell whose index of refraction is negative and close to zero. Further, we combine LHM and antenna. Simulation and measurement results show that the LHM is effective. The reflection coefficient of antenna does not change much by the combination of proposed LHM. The half power beam－width of antenna become narrower. The antenna gain improvement can be about 3 dB or higher.
Finally, the LHM has been miniaturized successfully, resulting in reduction in size by about 50%. Comparing simulation and measurement, we find the LHM is still effective. A dipole antenna is used to verify out design. The antenna gain has been enhanced and the reflection coefficient does not change much.

目錄
致謝................................................................I
中文摘要..........................................................III
英文摘要..........................................................IV
目錄...............................................................V
圖表目錄..........................................................VII
表格.............................................................IX

第一章 序論................................................1
1-1研究背景及動機.....................................1
1-2 研究方法..............................................2

第二章 基本原理..................................................3
2-1 左手材料由來.........................................3
2-2 負介電常數之人工結構.................................7
2-3 負導磁係數之人工結構.................................9
2-4 具有負介電常及負導磁係數之雙負人工材料..............11
2-5 集中波束原理........................................12

第三章 雙負左手材料單位晶胞分析.................................14
3-1 具負導磁係數之結構..................................15
3-2 具負介電係數之結構..................................18
3-3 同時具有雙負之左手材料..............................21


第四章 對天線之返回損失有低敏感度且具指向性提升之左手材料.......24
4-1 左手材料之排列架構分析..............................24
4-1-1實際應用架構..................................24
4-1-2 LHM不同排列方式.............................25
4-2 左手材料結合微帶天線................................25
4-2-1 簡介.........................................25
4-2-2 不同排列方式對天線增益之關係.................25
4-2-3 左手材料與天線結合...........................28
4-3 左手材料結合微帶天線量測結果........................31
4-3-1實做成品......................................31
4-3-2量測結果比較模擬結果…........................32
4-4 小結................................................35

第五章 縮小化之左手材料且具有低敏感度特性.......................37
5-1 縮小化之源由........................................37
5-2 電容性對等效參數之影響..............................37
5-3 縮小化之單位晶胞分析................................40
5-4 縮小化之左手材料結合微帶天線........................43
5-5 縮小化之左手材料結合微帶天線量測結果................47
5-5-1 實做成品.....................................47
5-5-2 量測結果比較模擬結果.........................48

第六章 左手材料延伸應用.........................................53

第七章 總結.....................................................56

參考文獻...........................................................57

參考文獻

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