臺灣博碩士論文加值系統

本論文利用T型微帶天線的設計理念應用至圓柱狀微帶結構來設計具尺寸縮小化與雙頻操作的圓T型微帶天線，而主要的理念是利用結構延伸之技術形成兩段不同之共振徑長來決定高低頻模態，並且增加圓形天線結構邊界上不同的磁流分量進而輻射之可調性變大，因此單一模態可用之限制得以改善。
對於圓T型天線之特性，數據顯示結構延伸的技術使電場扭曲的現象不但增加的側邊輻射磁流的多樣性，單波束輻射的兩模態可形成，結構邊界的改變使內部電場偏移的情形也證實了這種結構延伸之設計概念的合理性。而依據比較結果，此天線也具縮小天線尺寸之功能。而對於結構參數改變之探討，內徑以及延伸結構的夾角可分別用來大幅度調整或者微調兩模態共振頻率之間距，並且本論文也提出適當的調整範圍有助於此類天線之應用。又當圓T理念應用於圓柱天線結構的切割時，可具雙頻操作的圓凹型之微帶天線更顯示此理念具高設計之彈性。
分析方式而言，本論文先探討基本圓柱微帶結構之特性的處理方式不但使圓T型天線的分析更容易掌握了許多，空腔模式的理論以及兩區劃分搭配Moment Method之技術也有效的掌握了此天線的基本特性以及證實此天線的設計概念。而且模擬以及實驗的輔助驗證了理論所得結果之正確性以及此天線確實具雙頻之功能。
圓T型與圓凹型天線之延伸與切割技術可使天線具高設計自由度，因此若天線能藉多重之延伸與切割技術增加結構之可調性，則設計具更多頻之天線是可期的。除此之外，若此設計理念若能用來設計出具圓極化之功能的天線，則圓T理念的應用價值將更高。

This thesis uses the concept of T-shape microstrip antenna to cylindrical microstrip structure to design a circular T-shape microstrip antenna with size reduction and dual-band operation. The main design concept is to extend structure, and the low and high modes are decided by two different resonance path length. The component of magnetic current on structure boundary increases, then freedom of radiation can be improved, the limitation of single mode is also improved.
For the characteristics of circular T-shape microstrip antenna, results show that technique of extended structure can not only change distribution of electric field to increase the freedom of radiation magnetic currents on sides of antenna, two modes with single-beam radiation can be achieved. The offset distribution of electric field also verifies the validity of design concept. According to the comparison, results show that this design also can reduce antenna size. According to the research result on structure parameters, inner radius and angle of extended structure can widely or slightly adjust the separation of two resonant frequencies respectively, and this thesis also provides suitable tunable range, so it is useful for future applications. When the concept of circular-T is applied to cutting cylindrical microstrip structure, circular-notch microstrip antenna can also operate with dual-band, this result show the high flexibility of design concept.
For analysis method, this thesis the investigates basic circular microstrip antenna first, since the analysis of circular-T antenna is easier to understand. Besides, the theoretic cavity model and region division with moment method technique can investigate basic characteristics of the circular-T antenna and prove design concept. Simulation and experiment verify the validity of theoretical data, and the dual-band operation of antenna.
The design technique of circular-T and circular-notch microstrip antennas can increase design flexibility, therefore, if structure freedom can be increased by extension or cutting, design of multi-band can be expected. Moreover, if the design concept can be used to design antenna with circularly polarization, the application value of circular-T concept will be much more higher.

摘要i
英文摘要ii
致謝iii
目錄iv
圖目錄v
表目錄ix
第一章 緒論1
1-1 歷史背景與研究動機1
1-2 設計方式與分析方式2
1-3 論文架構3
第二章 基本圓形微帶式天線4
2-1 圓形微帶天線理論分析的建立4
2-2 共振頻率與電場分佈之探討9
2-3 磁流分析與輻射場型之探討10
2-4 結論11
第三章 具雙頻操作的單層圓T型微帶天線26
3-1 圓T型微帶天線相關參數之推導26
3-2 圓T型微帶天線輻射場之推導33
3-3 圓T型微帶天線之特性探討35
3-4 結論38
第四章 圓T型微帶天線特性之探討及其延伸之應用56
4-1 徑長改變之影響56
4-2 凸出之環形結構尺寸改變之影響57
4-3 延伸之應用58
4-4 結論58
第五章 總結與討論75
參考文獻77
圖目錄
圖2.1 單層圓形微帶天線之示意圖13
圖2.2 對於圖2.1圓形微帶天線之共振腔示意圖14
圖2.3 對於圖2.1圓形微帶天線，理論所得的各TM模態之共振頻率示意圖15
圖2.4 對於圖2.1圓形微帶天線，在遠場處所觀察到之磁流示意圖16
圖2.5 對於圖2.1圓形微帶天線的最低模態TM110，由理論與模擬所得之電場分佈圖18
圖2.6 對於圖2.1圓形微帶天線的最低模態TM110，在橫剖面上，由理論所得之整體的電場分佈圖19
圖2.7 對於圖2.1圓形微帶天線的第三模態TM010，由理論與模擬所得之電場分佈圖20
圖2.8 對於圖2.1圓形微帶天線的第三模態TM010，在橫剖面上，由理論所得整體的電場分佈圖21
圖2.9 對於圖2.1的圓形微帶天線，TM110模態之磁流分佈示意圖22
圖2.10 對於圖2.1圓形微帶天線之TM110模態，由理論與模擬所得之輻射場型23
圖2.11 對於圖2.1的圓形微帶天線，TM010模態之磁流分佈示意圖24
圖2.12 對於圖2.1圓形微帶天線之TM010模態，由理論與模擬所得之E平面輻射場型25
圖3.1 為單層圓T型微帶天線之結構圖39
圖3.2 為圖3.1之圓T型微帶天線之共振腔示意圖40
圖3.3 為圖3.1之圓T型微帶天線共振腔分區示意圖41
圖3.4 為圖3.1之圓T型微帶天線的磁流分佈的示意圖42
圖3.5 對於圖3.1之圓T型微帶天線，理論、實驗與模擬之Return loss數據43
圖3.6 對於圖3.1之圓T型微帶天線，基底數對共振頻率所造成之影響45
圖3.7 對於圖3.1之圓T型微帶天線，諧波數與基底數比值對共振頻率變化所造成之影響46
圖3.8 對於圖3.1之圓T型微帶天線，基底係數 與各個基底數的關係圖47
圖3.9 對於圖3.1之圓T型微帶天線，位於圓心偏右 的橫剖面上，理論所得低頻模態的電場分佈圖48
圖3.10 對於圖3.1之圓T型微帶天線，位於圓心偏右 的橫剖面上，理論所得高頻模態的電場分佈圖49
圖3.11 對於圖3.3之圓T型微帶天線，在第Ⅰ區內，沿 方向上，由理論與模擬所得之電場分佈圖50
圖3.12 對於圖3.1之圓T型微帶天線，在位於圓心偏右 的橫剖面上，由理論與模擬所得電場分佈圖51
圖3.13 對於圖3.1之圓T型微帶天線，由理論所得圓心偏右 與偏左 之整體的橫剖面電場分佈圖52
圖3.14 對於圖3.1之圓T型微帶天線，由理論與模擬所得的TM110模態輻射場型53
圖3.15 對於圖3.1之圓T型微帶天線，由理論與模擬所得的TM120模態輻射場型54
圖4.1 對於圖3.1的圓T型微帶天線的兩模態，由理論與模擬所得的共振頻率與a/(a+b)之關係圖60
圖4.2 對於圖3.1的圓T型微帶天線，由模擬所得的TM110模態之輻射場型61
圖4.3 對於圖3.1的圓T型微帶天線，由模擬所得的TM120模態之輻射場型62
圖4.4 對於圖3.1的圓T型微帶天線的TM110模態，由模擬所得之Co-pol.和Cross-pol.峰值之差距與內徑長a的關係圖63
圖4.5 對於圖3.1的圓T型微帶天線的TM120模態，由模擬所得之E平面輻射場Co-pol.峰值凹陷程度與內徑長a的關係圖64
圖4.6 對於圖3.1的圓T型微帶天線的TM120模態，由模擬所得之H平面輻射場Co-pol.以及Cross-pol.峰值與內徑長a的關係圖65
圖4.7 對於圖3.1的圓T型微帶天線兩模態，由理論與模擬所得的共振頻率與環形夾角 之關係圖66
圖4.8 對於圖3.1的圓T型微帶天線的最低兩模態，由模擬所得的阻抗與環形夾角 之關係圖67
圖4.9 對於圖3.1的圓T型微帶天線的TM110模態，由模擬所得之輻射場型68
圖4.10 對於圖3.1的圓T型微帶天線的TM120模態，由模擬所得之輻射場型69
圖4.11 對於圖3.1的圓T型微帶天線的輻射場，由模擬所得之Co-pol.和Cross-pol.峰值之差距與 值的關係圖70
圖4.12 雙圓凹型的微帶天線之示意圖71
圖4.13 對於圖4.12之圓凹型微帶天線，由模擬所得之S11數據72
圖4.14 對於圖4.12的圓凹型微帶天線的TM1模態，由模擬所得之輻射場型73
圖4.15 對於圖4.12的圓凹型微帶天線的TM3模態，由模擬所得之輻射場型74
表目錄
表2.1 對於圖2.1圓形微帶天線，由模擬與理論所得不同模態之共振頻率17
表3.1 對圖3.1之圓T型微帶天線，在不同尺寸下，模擬與理論之兩模態共振頻率與相對應之誤差值百分比44
表3.2 相同面積下(29.66cm2)，模擬所得之圓T型與T型微帶天線之共振頻率表55
表3.3 相同面積下(29.66cm2)，理論所得之圓T型與雙支幹圓形天線之共振頻率表55

中文部份
[1]戴崇倫, 具雙頻操作的單層T型微帶天線, 碩士論文, 義守大學電子工程研究所, 台灣, 高雄, 2011.
英文部份
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