臺灣博碩士論文加值系統

本論文所設計之應用於無線區域網路(Wireless Local Area Network；WLAN)多輸入輸出之單極天線，其阻抗頻寬符合IEEE 802.11 a/b/g/n/ac之相關規範。
目前常有WLAN天線共用的同頻干擾問題，在業界基本規格要求裡我們隔離度(Isolation)要小於 -40 dB；反射損耗(Return loss)要小於 -6dB才能保證天線之間正常工作，但本篇論文以學術標準來製作，隔離度(Isolation)要小於 -20 dB；反射損耗(Return loss)要小於 -10 dB。本論文特別設計於兩天線在同距離的情況之下，使用二種不同的方式實現隔離度的改善與天線阻抗匹配，方法一使用獨立的隔離器(Isolator)接於天線端，改善阻抗匹配與隔離度目的，方法二則對天線接地面做挖槽式(Slot)結構改變，也達成改善阻抗匹配與隔離度。方法一較方法二減少約三分之一的空間需求，但方法二的阻抗匹配與隔離度較方法一來的好，二種方法特性之間各有優缺點，我們會將各實驗結果以表格呈現出來，同時也將目前天線朝向小型化設計的需求。最後本論文會將模擬與無反射室所量測到的實測數據相互比較並分析。

關鍵詞：無線區域網路、多輸入多輸出、單極天線、隔離器、挖槽

This thesis focuses on the issues of isolation and return loss between emitter/radiator in a multi-input, multi-out (MIMO) antenna unit. The antennas were designed for Wireless Local Area Network (WLAN) operation in accordance to part of IEEE 802.11 a/b/g/n/ac low frequency band (2.4 GHz ~ 2.5 GHz) and high frequency band (5.2 GHz ~ 5.8 GHz). The area of the antenna is 13 x 17.5 mm2 printed on FR4 substrate of area 100 x 80 mm2. In this work, isolators of different structures were studied to investigate their isolation capability between two meander monopole antennas. Two different methodologies for implementing the isolator will be considered. The first of which is to insert an independent isolator between the two antennas to achieve impedance matching and isolation and the second mean is to introduce different slotted ground attain the aim. In general, both methods have their own merits but the latter seems to present better performance in term of isolation capability and impedance matching. Our work also took into account of the current demand for miniaturization of the MIMO unit. Throughout the work, simulation analysis and actual measurements in an anechoic chamber will be compared.

Keyword：WLAN、MIMO、Monopole、Isolator、Slot

摘要
ABSTRACT
致謝
目次
圖次
表次
第一章 序論
1.1 研究背景
1.2 研究動機與方向
1.3 研究內容
第二章 天線理論與文獻探討
2.1 傳輸線結構
2.2 偶極天線(Dipole Antenna)
2.3 單極天線(Monopole Antenna)
2.4 文獻回顧
第三章 具有諧振器之改善隔離度與阻抗匹配之雙頻單極天線設計 14
3.1 設計概述
3.2 天線與諧振器設計
3.2.1 垂直彎繞諧振器設計
3.2.2 雙邊垂直彎繞諧振器設計
3.2.3 水平彎繞諧振器設計
3.3 模擬與實驗結果分析
3.4 心得與討論
第四章 天線接地挖槽之改善隔離度與阻抗匹配之雙頻單極天線設計 57
4.1 設計概述
4.2 天線與接地面設計
4.2.1 T字型挖槽接地面設計
4.2.2 曲折型單邊挖槽接地面設計
4.2.3 曲折型雙邊挖槽接地面設計
4.3 模擬與實驗結果分析
4.4 心得與討論
第五章 結論與未來展望
參考文獻

[1] J. W. Wallace, M. A. Jensen, A. L. Swindlehurst, and B. D. Jeffs,“Experimental character - ization of the MIMO wireless channel：Data acquisition and analysis,”IEEE Trans. Wireless Commun.,vol. 2, no. 2, pp. 335-343, Mar. 2003.
[2] C. T. Lee and K. L. Wong,“Uniplanar printed coupled-fed PIFA with a band-notching slit for WLAN/WiMAX operation in the laptop computer,”IEEE Trans. Antenna Propagat., vol. 57, no. 2, pp. 1252-1258, Apr. 2009.
[3] W. Wang S. S. Zhong and S. B. Chang,“A novel wideband coplanar-fed monopole antenna,”Microwave Opt. Tech. Lett., vol.43, pp. 50-52, 2004.
[4] C. I. Lin and K. L. Wong, “Printed monopole slot antenna for internal multiband mobile phone antenna,”IEEE Trans. Antenna Propagat., vol. 55, pp. 3690-3697,Dec. 2007.
[5] X. C. Lin and C. C. Yu, “A dual-band CPW-fed inductive slot-monopole hybrid antenna,”IEEE Trans. Antenna Propagat.,vol. 56, pp. 282-285, Jan. 2008.
[6] K. L. Wong and L. C. Lee, “Multiband printed monopole slot antenna for WWAN operation in the laptop computer,”IEEE Trans. Antennas Propagat., vol. 57, pp. 324-330, Feb. 2009.
[7] W. S. Chen and K. Y. Ku,“Band-rejected design of the printed open slot antenna forWLAN/WiMAX operation,”IEEE Trans. Antennas Propagat. , vol. 56, pp. 1163-1169, Apr 2008.
[8] J. Y. Sze, C. I. Hsu and S. C. Hsu,“Design of a compact dual-band annular-ring slot antenna,”IEEE Antennas Wireless Propagat. Lett., vol. 6, pp. 423-426, 2007.
[9] C. J. Wang and S. W. Chang,“A technique of bandwidth enhancement for the slot antenna,”IEEE Trans. Antennas Propagat. , vol. 56, pp. 3321-3324, Oct. 2008.
[10] K. V. Caekenberghe, N. Behdad, K. M. Brakora and K. Sarabandi,“A 2.45-GHz electrically small slot antenna,” IEEE Antennas Wireless Propagat. Lett. , vol. 7, pp. 346-348, 2008.
[11] L. Liu, S. Zhu and R. Langley,“Dual-band triangular patch antenna with modified ground plane,”Electron. Lett., vol. 43, pp. 140-141, Feb. 2007.
[12] Y. Zhang, W. Hong, C. Yu, Z. Q. Kuai, Y. D. Don and J. Y. Zhou,“Planar ultrawideband antennas with multiple notched bands based on etched slots on the patch and/or split ring resonators on the feed line,”IEEE Trans. Antennas Propagat. , vol. 56, pp. 3063-3068, Sep. 2008.
[13] C. F. Jou, J. W. Wu and C. J. Wang,“Novel broadband monopole antennas with dual-band circular polarization,”IEEE Trans. Antennas Propagat. , vol. 57, pp. 1027-1034, Apr. 2009.
[14] C. Y. Chiu, K. M. Shum and C. H. Chan,“A tunable via-patch loaded PIFA with size reduction,”IEEE Trans. Antennas Propagat. , vol. 55, pp. 65-71, Jan. 2007.
[15] S. H. Wong, K. L. Lau and K. M. Luk,“Wideband folded shorted patch antenna with double L-slots,”2007 IEEE Ap Int. Symp. Dig. , pp. 889-892, June. 2007.
[16] R. A. Bhatti and S. O. Park,“Hepta-band internal antenna for personal communication handsets,”IEEE Trans. Antennas Propagat. , vol. 55, pp. 3398-3403, Dec. 2007.
[17] P. W. Chan, H. Wong and E.K. N. Yung,“Wideband planar inverted-F antenna with meandering shorting strip,”Electron. Lett. , vol. 44, pp. 395-396, Mar. 2008.
[18] C. T. Lee and K. L. Wong,“Uniplanar printed coupled-fed PIFA with a band-notching slit for WLAN/WiMAX operation in the laptop computer,”IEEE Trans. Antennas Propagat. , vol. 57, pp. 1252-1258, Apr. 2009.
[19] Y. C. Yu and J. H. Tarng, “A novel modified multiband planar Inverted-F Antenna,”IEEE Antennas Wireless Propagat. Lett. , vol. 8, pp. 189-192, 2009.
[20] C. S. Hong,“Small annular slot antenna with capacitor loading,”Electron. Lett. , vol. 36, pp. 110-111, Jan. 2000.
[21] H. Iizuka, K. Sakakibara and N. Kikuma,“Stub-and capacitor-loaded folded dipole antenna for digital terrestrial TV reception,”IEEE Trans. Antennas Propagat. , vol. 56, pp. 215-222, Jan. 2008.
[22] T. H. Chand and J. F. Kiang,“Dualband split dielectric resonator antenna,”IEEE Trans. Antennas Propagat. , vol. 55, pp. 3155-3162, Nov. 2007.
[23] S. Mei and Z. Y. Ping,“A chip antenna in LTCC for UWB radies,”IEEE Trans. Antennas Propagat. , vol. 56, pp. 1177-1180, Apr. 2008.
[24] Y. C. Huang, W. F. Su and J. F. Kiang,“Wideband dielectric resonator antenna with a tunnel,”IEEE Antennas Wireless Propagat. Lett. , vol. 7, pp. 275-278, 2008.
[25] H. M. Chen, Y. K. Wang, Y. F. Lin, S. C. Lin and S. C. Pan,“A Compact dual-band dielectric resonator antenna using a parasitic slot,”IEEE Antennas Wireless Propagat. Lett. , vol. 8, pp. 173-176, 2009.
[26] Y. Murakami, W. Chujo, I. Chiba and M. Fujise,“Dual slot-coupled microstrip antenna for dual frequency operation,”Electron. Lett. , vol. 29, pp. 1906-1907, Oct. 1993.
[27] M. Deepukumar, J. George, C. K. Aanandan, P. Mohanan and K. G. Nair,“Broadband dual frequency microstrip antenna,”Electron. Lett. , vol. 32, pp. 1531-1532, Aug. 1996.
[28] J. S. Chen and K. L. Wong,“A single-layer dual-frequency rectangular microstrip patch antenna using a single probe feed,”Microwave Opt. Technol. Lett. , vol. 11, pp. 83-84, 1996.
[29] A. A. Serra, P. Nepa, G. Manara, G. Tribellini and S. Cioci,“A wide-band dual-polarized stacked patch antenna,”IEEE Antennas Wireless Propagat. Lett. , vol. 6, pp. 141-143, 2007.
[30] K. L. Lau, K. C. Kong and K. M. Luk,“Dual-band stacked folded shorted patch antenna,”Electron. Lett. , vol. 43, pp. 789-790, Jul. 2007.
[31] M. A. Matin, B. S. Sharif and C. C. Tsimenidis,“Probe fed stacked patch antenna for wideband application,”IEEE Trans. Antennas Propagat. , vol. 55, pp. 2385-2388, Aug. 2007.
[32] Z. Wang, S. Fang, S. Fu and S. Lu,“Dual-band probe-fed stacked patch antenna for GNSS application,”IEEE Antennas Wireless Propagat. Lett. ,vol. 8, pp. 100-103, 2009.
[33] S. H. Wi, Y. S. Lee and J. G. Wook,“Wideband microstrip patch antenna with U-S-shaped parasitic,”IEEE Trans. Antennas Propagat. ,vol. 55, pp. 1196-1199, Apr 2007.
[34] R. Janaswamy and D. H. Schaubrt,“Characteristic Impedance of a Wide Slotline on Low Permittivity Substrates,”IEEE Trans. , vol. 34, no. 8, pp. 900-902, Aug. 1986.
[35] H. J. Jiang, Y. C. Kao, K. L. Wong,“High-Isolation WLAN MIMO Laptop Computer Antenna Array,”Proceedings of APMC, vol. 6, pp.4-7, Dec. 2012.
[36] 游仲達，應用於筆電中WLAN之高隔離度天線設計，碩士論文，國立台北科技大學，台北，2012。