本論文提出應用於平板通訊裝置的環圈天線頻寬增加技術，能夠在小尺寸且低姿勢的天線下涵蓋LTE/WWAN (698~960/1710~2690 MHz) 的操作，所提出之技術可以在不影響環圈天線高頻的寬頻表現下，有效增加低頻的頻寬，第一個天線設計由電感性耦合支路與環圈天線組成，兩者產生之模態可以讓天線設計於10 ∗ 34.5 mm2的面積下涵蓋雙寬頻操作。第二個天線設計利用一組高通匹配電路在低頻增加一個額外模態，可以在10 ∗ 30 ∗ 3 mm3的尺寸下達成LTE/WWAN的頻寬需求。為進一步降低天線設計的高度，第三個天線設計利用了耦合式饋入的環圈天線型式，再加入高通匹配電路形成額外共振零點改善了低頻頻寬，於高度更低的8 ∗ 40 ∗ 3 mm3之天線尺寸下同樣可滿足698~960 MHz與1710~2690 MHz的寬頻操作。三個天線設計皆可因結構與匹配電路特性來獨立改善在低頻的表現，而不影響到高頻頻寬，也因小尺寸與低姿勢的天線尺寸，相當適合配置於現今窄邊框設計的平板通訊裝置中。論文也說明了其中高通匹配電路的設計方式及操作機制，提供了未來一種在不增加天線設計面積下的增加操作頻寬方式。

The techniques for bandwidth enhancement of loop antennas in the tablet communication devices are proposed. For LTE/WWAN operation and the demand of small-size and low-profile antennas, the proposed techniques widen the bandwidth of the lower band with very slight or almost no effects on the wide bandwidth of the higher band. The first proposed antenna is formed by integrating an inductive coupled branch strip to a loop antenna. The integration of the two structures makes the proposed antenna cover two wide operating bands with an occupied area of 10 ∗ 34.5 mm2. In the second proposed antenna, based on using a high-pass matching circuit to cause an additional mode generated in the lower band, the proposed antenna can meet the bandwidth requirement of LTE/WWAN operations with a size of 10 ∗ 30 ∗ 3 mm3. In order to achieve a lower profile of the antenna, a couple-fed loop antenna is applied in the third proposed design. By adding a high-pass matching circuit, an additional resonance can be created to widen the bandwidth of the lower band. The proposed antenna can cover 698~960 MHz and 1710~2690 MHz bands for a lower-profile antenna with a size of 8 ∗ 40 ∗ 3 mm3. Owing to loop antenna structure and the used matching circuits, the three proposed antennas can in general independently widen the bandwidth of the lower band without affecting the high-band bandwidth. Because of the small size and low profile, the proposed antennas are very suitable for narrow-frame communication devices. Details of the matching circuit techniques and their operating principle are analyzed. The proposed techniques provide a method of bandwidth enhancement without increasing the antenna volume occupied for achieving the LTE/WWAN operation in the 698~960/1710~2690 MHz bands.

目錄+i
圖次+iii
第一章 序論 (Introduction)
1.1 研究動機+1
1.2 文獻導覽+2
1.3 論文提要+3
第二章 應用電感性耦合支路改善操作頻寬之LTE/WWAN環圈天線 (Using Inductively Coupled Branch Strip for Bandwidth Enhancement of the LTE/WWAN Loop Antenna)
2.1利用環圈天線與支路耦合改善匹配之原理+4
2.2 電感性耦合支路參數分析+12
2.3 心得與討論+16
第三章 以匹配電路改善操作頻寬之LTE/WWAN環圈天線 (Using Matching Circuit for Bandwidth Enhancement of the LTE/WWAN Loop Antenna)
3.1天線操作原理及匹配電路分析+17
3.2高通匹配電路晶片元件選擇分析+26
3.3心得與討論+29
第四章 耦合式環圈天線結構搭配匹配電路於LTE/WWAN之操作 (Coupled-Fed Loop Antenna with Matching Circuit for the LTE/WWAN Operation)
4.1天線結構與匹配電路技術分析+31
4.2參數分析+38
4.3心得與討論+40
第五章 結論 (Conclusions)+41
參考文獻 (References)+43
論文著作表 (Publication List)+46

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