隨著無線通訊技術的快速發展，人們對於天線的需求是越來越大。有時當我們需要對特定方向集中能量或著是需要較遠的傳輸距離，指向性天線對我們就能有很大的幫助。指向性天線是一種能夠集中能量對準特定方向的天線，由於指向性天線的集中能量，使它擁有較高的增益，也使天線傳輸的距離增加許多。想要達到輻射場型指向性的效果，除了八木天線外，現今的主流多使用陣列天線來達到此目標。所謂陣列天線是由許多相同的單個天線按照一定的規律排列組成的天線系統。每個天線依照天線饋入電流，間距等不同參數產生天線間輻射的破壞性干涉和建設性干涉，天線間輻射的建設性干涉產生筆形波束(pencil beam)，而因為筆形波束的產生，造就了天線有高增益、高指向性的特點。而在生活中，由於每個天線的極化方向都不一定相同，因此容易造成發射天線與接收天線之間的極化損失。本論文提出兩種圓極化可切換陣列天線，此兩種方式皆是以最基本的貼片陣列天線(patch array antenna)為基礎。        第一種設計為平面極化可切換2×2陣列天線，此天線藉由控制天線上PIN diode的狀態進行線性極化與圓極化之間的切換。第二種設計是以不改變傳統矩形陣列天線結構及傳輸線的情況下，加上寄生元件以達到極化切換的效果，此點為本論文與其他文獻相比的一大優勢。此兩種設計也都非常適合應用在現代的通信系統當中。

With the rapid development of wireless communication technology, people's demand for antennas is increasing. Sometimes when we need to concentrate energy in a specific direction or need a longer transmission distance, directional antennas can be of great help to us. A directional antenna is an antenna that can concentrate energy in a specific direction. Due to the concentrated energy of a directional antenna, it has a higher gain and also increases the transmission distance of the antenna. In order to achieve the effect of a directional radiation pattern, in addition to the Yagi antenna, the mainstream nowadays mostly uses an array antenna to achieve this goal. The so-called array antenna is an antenna system composed of many identical single antennas arranged according to a certain rule. Each antenna produces destructive interference and constructive interference of radiation between antennas according to different parameters such as the current fed to the antenna and the spacing. The constructive interference of radiation between antennas produces a pencil beam, and because of the generation of the pencil beam, The antenna has the characteristics of high gain and high directivity. In the practical situation, since the polarization direction of each antenna is not necessarily the same, it is possible to cause polarization loss between the transmitting antenna and the receiving antenna.
 In this thesis, two circular polarization switchable array antennas are proposed. Both of these methods are based on the most basic patch array antenna. The first design is a planar polarization switchable 2×2 antenna array, whose polarization can be switched between linear polarization and circular polarization by configuring a short-circuit pin on the patch antenna. The second design can change its polarization by just adding a parasitic layer without modifing the main structure of the patch array and the transmission line. Which is a major advantage of the proposed design compared with other references. Both of these two designs are very suitable for morden communication systems.

目錄
中文摘要 ...................................................................................................... I
英文摘要 .................................................................................................... III
目錄 .............................................................................................................. V
圖目錄 ...................................................................................................... VII
表目錄 ...................................................................................................... XII
第一章、緒論 .............................................................................................. 1
1.1 研究動機與背景 ............................................................................ 1
1.2 文獻探討 ......................................................................................... 2
1.3 章節介紹 .......................................................................................... 4
第二章、極化可切換微帶陣列天線概述 ................................................ 5
2.1 陣列天線介紹 ................................................................................ 5
2.2 極化介紹 ......................................................................................... 9
2.3 極化切換技術 .............................................................................. 13
第三章、平面式圓極化可切換微帶陣列天線 ...................................... 17
3.1 平面式圓極化可切換微帶陣列天線之單元設計 .................... 17
3.2 平面式2×2 陣列天線結構設計 ................................................ 31
3.3 模擬結果 ...................................................................................... 37
第四章、疊構式圓極化可切換微帶陣列天線 ...................................... 41
4.1 疊構式圓極化可切換微帶陣列天線之單元設計 ........................ 41
4.2 疊構式2×2 陣列天線結構設計與模擬結果 ................................... 53
第五章結論 ................................................................................................ 59
參考文獻 .................................................................................................... 61


圖目錄
圖2.1 微帶陣列天線[12] .................................. 7
圖2.2 微帶天線[13] ...................................... 7
圖2.3 陣列天線場型圖[12] ................................ 8
圖2.4 垂直極化電場示意圖[14] ............................ 9
圖2.5 水平極化電場示意圖[14] ............................ 9
圖2.6 垂直極化向量圖 ................................... 10
圖2.7 水平極化向量圖 ................................... 10
圖2.8 橢圓極化示意圖[15] ............................... 11
圖2.9 圓極化示意圖[16] ................................. 12
圖2.10 (a)文獻天線結構圖 (b)pin diode 開關結果圖 [1] .... 14
圖2.11 (a)文獻天線結構圖 (b)pin diode 開關結果圖 [2] .... 15
圖2.12 文獻天線結構圖[3] ............................... 15
圖2.13 文獻天線結構圖[4] ............................... 16
圖3.1 平面式陣列天線單元結構圖 (a)正面(b)背面 ............ 18
圖3.2 平面式陣列天線單元四分之一波長阻抗轉換器 ......... 20
圖3.3 50 歐姆邊緣饋入史密斯圖 .......................... 20
圖3.4 具四分之一波長阻抗轉換器饋入反射係數圖 ........... 21
圖3.5 圓形天線結構圖 ................................... 22
圖3.6 圓形天線接地金屬位置參數變化反射係數圖 ........... 22
圖3.7 圓形天線接地金屬位置參數變化軸比圖 ............... 23
圖3.8 圓形天線圓極化電流圖 (a)phase=0 deg (b)phase=90 deg
(c)phase=180 deg (d)phase=270 deg ...................... 24
圖3.9 圓形天線圓極化輻射場型圖 (a)XZ 平面 (b)YZ 平面 ..... 24
圖3.10 圓形天線垂直極化反射係數圖 ...................... 25
圖3.11 圓形天線裁切示意圖 .............................. 26
圖3.12 L1 反射係數圖參數分析 ........................... 26
圖3.13 圓形天線裁切後新接地金屬位置 .................... 27
圖3.14 平面式陣列天線單元PIN-Diode 開關環形槽孔 ............ 28
圖3.15 平面式陣列天線單元加上環形槽孔反射係數圖 ........ 29
圖3.16 平面式陣列天線單元加上環形槽孔軸比圖 ............ 29
圖3.17 平面式陣列天線單元加上環形槽孔圓極化輻射場型圖
(a)XZ 平面 (b)YZ 平面 ..................................... 30
圖3.18 平面式陣列天線單元加上環形孔槽垂直極化輻射場型圖
(a)XZ 平面 (b)YZ 平面 .................................. 30
圖3.19 兩平面式陣列天線單元排列 (a)X 方向E-plane 排列
(b)Y 方向H-plane 排列 ................................... 31
圖3.20 兩平面式陣列天線單元X 方向E-plane 排列S12圖 ..... 32
圖3.21 兩平面式陣列天線單元Y 方向H-plane 排列S12圖 ..... 33
圖3.22 平面式陣列天線單元130 歐姆傳輸線饋入 ............ 33
圖3.23 平面式陣列天線單元130 歐姆傳輸線饋入垂直極化與圓極
化反射係數圖 ........................................... 34
圖3.24 平面式陣列天線單元130 歐姆傳輸線饋入圓極化軸比圖
....................................................... 34
圖3.25 平面式2×2 陣列天線傳輸線結構圖 ................. 35
圖3.26 平面式2×2 陣列天線傳輸線相位延遲圖 ............. 36
圖3.27 平面式2×2 陣列天線結構圖 ...................... 37
圖3.28 平面式2×2 陣列天線垂直極化反射係數圖 ............ 38
圖3.29 平面式2×2 陣列天線圓極化反射係數圖 ............. 38
圖3.30 平面式2×2 陣列天線圓極化軸比圖 ................. 39
圖3.31 平面式2×2 陣列天線圓極化電流變化圖 ............. 39
圖3.32 平面式2×2 陣列天線圓極化輻射場型圖 (a) XZ 平面
(b) YZ 平面 ............................................ 40
圖3.33 平面式2×2 陣列天線垂直極化輻射場型圖 (a) XZ 平面
(b) YZ 平面 ............................................ 40
圖4.1 疊構式陣列天線單元結構圖(a)第一層設計結構 (b)第二層
設計結構(c)結構俯視圖 .................................. 42
圖4.2 傳統矩形線性極化天線阻抗匹配後反射係數圖 ......... 44
圖4.3 初時寄生金屬結構圖 ............................... 45
圖4.4 寄生金屬PIN-Diode 不同角度反射係數圖 ............. 46
圖4.5 寄生金屬PIN-Diode 為169 度軸比圖 ................. 46
圖4.6 寄生金屬具兩個PIN-Diode 結構圖 ................... 47
圖4.7 寄生金屬第二個PIN-Diode 不同角度反射係數圖 ....... 48
圖4.8 寄生金屬第二個PIN-Diode 角度為16 度軸比圖 ........ 48
圖4.9 初時寄生金屬結構垂直極化反射係數圖 ............... 49
圖4.10 寄生金屬挖槽結構圖 .............................. 50
圖4.11 L4 參數變化反射係數圖 ........................... 50
圖4.12 寄生金屬挖槽後圓極化反射係數圖 .................. 51
圖4.13 寄生金屬挖槽後圓極化軸比圖 ...................... 51
圖4.14 寄生金屬挖槽後垂直極化輻射場型圖 (a)XZ 平面 (b)YZ
平面 ................................................... 52
圖4.15 寄生金屬挖槽後圓極化輻射場型圖 (a)XZ 平面 (b)YZ 平
面 ..................................................... 52
圖4.16 寄生金屬挖槽後圓極化電流變化圖 (a)phase=0deg
(b)phase=90deg (c)phase=180deg (d)phase=270deg ......... 53
圖4.17 疊構式2×2 陣列天線結構圖 (a)第一層結構 (b)第二層結
構(c)結構俯視圖 ........................................ 55
圖4.18 疊構式2×2 陣列天線垂直極化反射係數圖 ............ 56
圖4.19 疊構式2×2 陣列天線垂直極化場型圖 (a)XZ 平面 (b)YZ
平面 ................................................... 56
圖4.20 疊構式2×2 陣列天線圓極化軸比圖 ................. 57
圖4.21 疊構式2×2 陣列天線圓極化反射係數圖 ............. 58
圖4.22 疊構式2×2 陣列天線圓極化輻射場型圖 (a)XZ 平面 (b)YZ
平面 ................................................... 58

表目錄
表2.1 不同個數微帶陣列天線結果表[12] .................... 8
表3.1 平面式陣列天線單元參數表 ......................... 19
表4.1 疊構式陣列天線單參數表 ........................... 43

參考文獻
[1]	R. K. Saraswat and M. Kumar, "A Reconfigurable Patch Antenna Using Switchable Slotted Structure for Polarization Diversity," 2015 Fifth International Conference on Communication Systems and Network Technologies, Gwalior, 2015, pp. 11-14
[2]	M. Tewari, A. Yadav and R. P. Yadav, "Polarization reconfigurable circular patch antenna: Parasitic stub," 2017 International Conference on Wireless Communications, Signal Processing and Networking (WiSPNET), Chennai, 2017, pp. 1083-1086
[3]	S. W. Lee and Y. J. Sung, "Reconfigurable Rhombus-Shaped Patch Antenna With Y-Shaped Feed for Polarization Diversity," in IEEE Antennas and Wireless Propagation Letters, vol. 14, pp. 163-166, 2015,
[4]	K. X. Wang and H. Wong, "A Reconfigurable CP/LP Antenna With Cross-Probe Feed," in IEEE Antennas and Wireless Propagation Letters, vol. 16, pp. 669-672, 2017
[5]	M. Saravanan and A. Priya, "A Compact Frequency and Polarization Reconfigurable Square Patch Antenna for Wireless Communication," 2018 IEEE MTT-S International Microwave and RF Conference (IMaRC), Kolkata, India, 2018, pp. 1-4
[6]	Y. Lu and S. Chen, "A modified U-slot patch antenna with full polarization agility," 2016 IEEE 5th Asia-Pacific Conference on Antennas and Propagation (APCAP), Kaohsiung, 2016, pp. 9-10
[7]	W. Lin and H. Wong, “A polariztion reconfigurable aperture-fed patch antenna array,” 2016 IEEE International Conference on Computational Electromagnetics (ICCEM), 2016. 
[8]	Joshua M. Kovitz, Harish Rajagopalan, Yahya Rahmat-Samii, "Design and Implementation of Broadband MEMS RHCP/LHCP Reconfigurable Arrays Using Rotated E-Shaped Patch Elements" in IEEE Transactions on Antennas and Propagation, vol. 63, no. 6, June 2015.
[9]	Qiang Liu, Zhi Ning Chen, Yuanan Liu, Fuhai Li,Yu Chen, and Zhiguang Mo, "A Circular Polarization and Mode Reconfigurable Wideband Orbital Angular Momentum Patch Array Antenna "in IEEE Transactions on Antennas and Propagation, vol. 66, no. 4, April 2018.
[10]	K. Li, Y. Shi, H. Shen, and L. Li, “A Characteristic-Mode-Based Polarization-Reconfigurable Antenna and its Array,” IEEE Access, vol. 6, pp. 64587–64595, 2018. 
[11]	B. Feng, L. Li, Q. Zeng, and C.-Y.-D. Sim, “A Low-Profile Metamaterial Loaded Antenna Array With Anti-Interference and Polarization Reconfigurable Characteristics,” IEEE Access, vol. 6, pp. 35578–35589, 2018. 
[12]	G. B. Hoang, G. N. Van, L. T. Phuong, T. A. Vu and D. B. Gia, "Research, design and fabrication of 2.45 GHz microstrip patch antenna arrays for close-range wireless power transmission systems," 2016 International Conference on Advanced Technologies for Communications (ATC), Hanoi, 2016, pp. 259-263,
[13]	“Design and Optimization of Rectangular Patch Antenna Based on FR4, Teflon and Ceramic Substrates.” Recent Advances in Electrical & Electronic Engineering (Formerly Recent Patents on Electrical & Electronic Engineering) 12, no. 4 (2019): 368–73.
[14]	“應用於5G之28GHz相位陣列模組.” 工研院資訊與通訊研究所, April 16, 2019.https://ictjournal.itri.org.tw/content/Messagess/contents.aspx?PView=1.
[15]	glw168 and glw168, “天線（通信中的重要部件）的基礎知識,” MY Notes BLOG, 03-Dec-2012. [Online]. Available: https://glw168.wordpress.com/2012/11/19/天線（通信中的重要部件）的基礎知識/.
[16]	Yow-Shyan  Lin. “Circularly Polarized Slotted Conductor- Backed Coplanar Waveguide Antenna Arrays with Sequential Rotation Feeding Methods.” Lnstitutional Reposioiry of NCTU , 2008. https://ir.nctu.edu.tw/bitstream/11536/42029/1/359101.pdf.