本論文提出可應用於LTE金屬機殼手機之小尺寸倒F形邊框天線。第一個天線為一IFA結構，利用短側邊框為53 mm(約900 MHz之0.16λ)作為輻射部，再藉由饋入電路以增加模態的頻寬，以涵蓋低頻824~960 MHz以及高頻1710~2690 MHz之雙寬頻操作。第二個天線為延續第一個天線設計的架構並加以簡化，同樣激發金屬邊框作為輻射部的倒F形天線的基頻及兩個倍頻模態，並搭配饋入電路增加模態的頻寬，以涵蓋低頻及中頻的操作頻寬，同時透過由金屬邊框形成的短路單極天線模態結合倒F形天線的倍頻模態於高頻頻帶達成寬頻操作，並在天線金屬淨空區僅為2 mm下，涵蓋低頻824~960 MHz、中頻1710~2690 MHz以及高頻3400~3800 MHz三寬頻操作，最後也藉由在短路端加入一電感可做切換使模態降頻，使低頻完整涵蓋704~960 MHz。另外也將第二個天線應用於2 × 2 MIMO系統，探討藉由適當的雙天線擺放方式得到降低的封包相關係數(ECC)，增加通道容量，提高傳輸速率。

Two small-size frame antennas for the LTE metal-casing smartphone are presented. Both antennas are based on the inverted-F antenna (IFA) structure. The first antenna uses a frame section of 53 mm (about 0.16 wavelength at 900 MHz) along the short edge of the metal casing as the IFA’s radiating strip. By adding the matching circuit to the IFA structure, the antenna can provide a dual-wideband LTE operation to cover the low band of 824~960 MHz and high band of 1710~2690 MHz. The second antenna follows the design rule of the first antenna and achieves a simplified structure. A fundamental mode and two higher-order modes of the IFA’s radiating strip can be generated for the second antenna. By adding the wideband matching circuit in the feeding strip of the antenna, additional resonances in the low and middle bands are created to widen the bandwidths thereof. At the same time, a resonant mode in the high band can be generated by a parasitic shorted monopole, which is also formed by a small frame section along the short edge of the metal casing. With three resonant modes generated and a metal clearance of 2 mm only, the antenna can provide a triple-wideband LTE operation to cover the 824~960/1710~2690/3400~3800 MHz bands. Moreover, by selecting different inductances of the inductor at the shorting strip of the IFA, the resonant mode of the antenna’s low band can be shifted, so that the low band of 704~960 MHz can be covered. For the MIMO study, two second antennas are applied for the 2 × 2 MIMO operation. Good envelope correlation coefficients (ECCs) of the two antennas can be obtained, and much higher channel capacities can be achieved.

論文審定書 i
致謝 ii
中文摘要 iii
英文摘要 iv
目錄 v
圖次 vi
第一章 序論 (Introduction)
1.1 研究動機 1
1.2 文獻導覽 2
1.3 論文各章節提要 2
第二章 LTE金屬機殼手機之雙寬頻倒F形邊框天線 (Dual-Wideband IFA Frame Antenna for the LTE Metal-Casing Smartphone)
2.1 天線結構介紹及技術原理說明 6
2.2 實驗結果與分析 14
2.3 心得與討論 18
第三章 LTE金屬機殼手機之三寬頻倒F形邊框天線 (Triple-Wideband IFA Frame Antenna for the LTE Metal-Casing Smartphone)
3.1天線結構及技術原理說明 20
3.2模擬及實驗結果分析 27
3.3倒F形LTE手機天線之MIMO效能分析 31
3.4延伸設計與討論 39
3.5心得與討論 42
第四章 結論 (Conclusions) 44
參考文獻 (References) 47
著作表 (Publication List) 50

[1] P. Bevelacqua, “Dynamically adjustable antenna supporting multiple antenna modes,” U.S. Patent No. 8982002 B2, Mar. 17, 2015.
[2] R. J. Hill, R. W. Schlub, and R. caballero, “Antennas for handheld electronic devices with conducting bevels,” U.S. Patent No. 7924231 B2, 2011.
[3] H. Chen and A. Zhao, “LTE antenna design for mobile phone with metal frame,” IEEE Antennas Wireless Propag Lett 15 (2016) (to appear)
[4] K. L. Wong and C. Y. Tsai, “IFA-based metal-frame antenna without ground clearance for the LTE/WWAN operation in the metal-casing tablet computer,” IEEE Trans. Antennas Propag., Vol. 64, pp. 53-60, Jan. 2016.
[5] Y. L. Ban, Y. F. Qiang, Z. Chen, K. Kang, and J. H. Guo, “A dual-loop antenna design for hepta-band WWAN/LTE metal-rimmed smartphone applications,” IEEE Trans. Antennas Propagat., vol. 63, pp. 48-58, 2015.
[6] C. K. Hsu and S. J. Chung, “Compact antenna with U-shaped open-end slot structure for multi-band handset applications,” IEEE Trans. Antennas Propagat., vol. 62, pp. 929-932, 2014.
[7] J. Zhong, R. M. Edwards, L. Ma, and X. Sun, “Multiband slot antennas for metal back cover mobile handsets,” Progress In Electromagnetics Research Lett., vol. 39, pp. 115-126, 2013.
[8] K. L. Wong and Y. J. Li, “Low-profile open-slot antenna with three branch slots for triple-wideband LTE operation in the metal-framed smartphone,” Microwave Opt. Technol. Lett., Vol. 57, pp. 2231-2238, Oct. 2015.
[9] K. L. Wong and P. R. Wu, “Dual-wideband linear open slot antenna with two open ends for the LTE/WWAN smartphone,” Microwave Opt. Technol. Lett., Vol. 57, pp. 1269-1274, Jun. 2015.
[10] LTE Frequency Bands & Spectrum Allocations-a summary and tables of the LTE frequency band spectrum allocations for 3G & 4G LTE - TDD and FDD, http://www.radio-electronics.com/
[11] P. W. Lin and K. L. Wong, “Dual-feed small-size LTE/WWAN strip monopole antenna for tablet computer applications,” Microwave Opt. Technol. Lett., Vol. 55, pp. 2571-2576, Nov. 2013.
[12] K. L. Wong and L. Y. Chen, “Small-size LTE/WWAN tablet device antenna with two hybrid feeds,” IEEE Trans. Antennas Propagat., Vol. 62, pp. 2926-2934, Jun. 2014.
[13] K. L. Wong and T. W. Weng, “Coupled-fed shorted strip antenna with an inductively coupled branch strip for low-profile, small-size LTE/WWAN tablet computer antenna,” Microwave Opt. Technol. Lett., Vol. 56, 2014 .
[14] K. L. Wong and S. N. Hsu, “Small-size two-branch monopole antenna with integrated wideband matching network for LTE tablet computer,” Microwave Opt. Technol. Lett., Vol. 57, pp. 507-513, Feb. 2015.
[15] K. L. Wong and Z. G. Liao, “Small-size dual-wideband monopole antenna with inductive and capacitive feeding branches for LTE tablet computer application,” Microwave Opt. Technol. Lett., Vol. 57, pp. 853-860, Apr. 2015.
[16] K. L. Wong, T. W. Kang, and M. F. Tu, “Internal mobile phone antenna array for LTE/WWAN and LTE MIMO operations,” Microwave Opt. Technol. Lett., vol. 53, pp. 1569-1573, 2011.
[17] H. Bae, F. J. Harackiewicz, M. Park, T. Kim, N. Kim, D. Kim, and B. Lee, “Compact mobile handset MIMO antenna for LTE700 applications,” Microwave Opt. Technol. Lett., vol. 52, pp. 2419-2422, 2010.
[18] Y. L. Ban, Z. X. Chen, Z. Chen, K. Kang, and J. Li, “Decoupled Closely Spaced Heptaband Antenna Array for WWAN/LTE Smartphone Applications,” IEEE Antennas and Wireless Propagation Letters, vol. 13, pp. 31-34, 2014.
[19] K. L. Wong and Y. J. Li, “Low-Profile Open-Slot Antenna with Three Branch Slots for Triple-Wideband LTE Operation in the Metal-Framed Smartphone,” Microwave Opt. Technol. Lett., vol. 57, Nov. 2015.
[20] K. L. Wong, Y. C. Wu, C. C. Wan, and W. Y. Li, “GPS/WLAN open-slot antennas with a sticker-like feed substrate for the metal-casing smartphone,” Microwave Opt. Technol. Lett., Vol. 58, May. 2016.
[21] http://www.ansys.com/Products/Electronics/ANSYS-HFSS
[22] K. L. Wong and M. T. Chen, “Small-size LTE/WWAN printed loop antenna with an inductively coupled branch strip for bandwidth enhancement in the tablet computer,” IEEE Trans. Antennas Propagat., Vol. 61, pp. 6144-6151, Dec. 2013.
[23] D. F. Darnell, W. J. Noellert, and M. P. Pascolini, “Antenna having flexible feed structure with components,” U.S. Patent Application Publication No.: 2015/0035706 A1, Feb. 5, 2015.
[24] M. S. Sharawi, “Printed multi-band MIMO antenna systems and their performance metrics,” IEEE Antennas and Propag. Mag., vol. 55, pp. 218-232, 2013.
[25] K. L. Wong, and Y. T. Hsieh, “Communication device and antenna element therein,” U.S. Patent Application Publication No.: 2014/0184466 A1, Jul. 3, 2014.
[26] K. L. Wong, Y. C. Chen, and W. Y. Li, “Four LTE low-band smartphone antennas and their 4 x 4 MIMO performance with user’s hand presence,” Microwave Opt. Technol. Lett., Vol. 58, Oct. 2016.
[27] K. L. Wong, J. Y. Lu, L. Y. Chen, W. Y. Li, and Y. L. Ban, “8-antenna and 16-antenna arrays using the quad-antenna linear array as a building block for the 3.5-GHz LTE MIMO operation in the smartphone,” Microwave Opt. Technol. Lett., Vol. 57, pp. 174-181, Jan. 2016.
[28] D. F. Darnell et al., “Tunable antenna system with multiple feeds,” U.S. Patent 8 798 554 B2, Aug. 5, 2014.