臺灣博碩士論文加值系統

近年來，無人飛行載具在多媒體、偵查、數據收集以及地形探勘等各領域廣泛應用，而應用於無人飛行載具之天線皆具有小型化與多頻等特性。一般無人機天線大都使用單一饋入的單頻帶天線，但在無人機體有限空間中放置多個天線會增加配置難度，於是本研究針對無人飛行載具需求之三個頻段UHF(915MHz) 、GPS頻段(1.575GHz)以及Wi-Fi頻段(2.45GHz)設計一多頻段多端口整合型天線，將三個頻段三個端口整合，讓三個頻段能在一個天線結構下同時運作。
本文所設計之天線採用同軸饋入，基板使用介電係數ε_γ為4.4的FR4板，天線設計採用三個弧形天線透過調整寬度、弧度達到目標頻段。其中，UHF頻段利用中心圓形貼片天線連接最外圍弧形天線，在小型化天線中獲得較長的電流路徑，而GPS/WiFi頻段之弧形天線透過加上凹槽在緊湊的天線裡將匹配頻段往低頻調整並提升阻抗匹配，在接地面上挖槽孔來提高天線間的隔離度以降低不必要的功率損耗。
本研究所提出之天線在Ansys HFSS模擬中得到以下結果:UHF頻段S11最佳值為-26.3dB，在-6dB處頻率範圍為910~933MHz；在GPS頻段最佳S22值則為-10.86dB，-6dB頻帶為1.558~1.602GHz；在Wi-Fi頻段的S33值最低可達-23.29dB，-6dB頻率範圍則是2.4~2.495GHz。在量測部分，在UHF頻段S11最佳值為-13.4dB，在-6dB處頻率範圍為908MHz-928MHz；在GPS頻段最佳S22值則為-12.6dB，-10dB頻帶為1.568GHz-1.59GHz；在Wi-Fi頻段的S33值最低可達-22.3dB，-6dB頻率範圍則是2.4GHz到2.485GHz。所提出之天線整體尺寸僅有50x50x0.8mm3，且多端口的結構極為適合放置在小型無人機上，支援無人機所需頻段與地面站進行通訊。

In recent years, unmanned aerial vehicles (UAVs) are widely used in various fields such as multimedia, reconnaissance, data acquisition, and terrain exploration. The antennas used in UAVs feature miniaturization and multi-frequency. Most UAV antennas use a single-feed single-band antenna, but placing multiple antennas in the limited space of a UAV can make the configuration more difficult. In this paper, a multi-band, multi-port antenna is designed for the UHF (915 MHz), GPS (1.575 GHz), and Wi-Fi (2.45 GHz) frequency bands used by unmanned aerial vehicles by integrating the three frequency bands and three ports into a single antenna structure to allow the three bands to operate simultaneously.
In this paper, the antenna is designed with coaxial feed and FR4 board with dielectric coefficient ε_r of 4.4. The antenna design features three curved antennas which can be adjusted in width and curvature for the target frequency band. For the UHF band, the center circular patch antenna is connected to the outermost curved antenna to obtain a longer current path in the miniaturized antenna. By adding a slot in the compact antenna, the matching frequency band of the GPS/WiFi antenna is adjusted to lower frequency, and impedance matching is also improved. Slotted holes are dug on the grounding surface to further isolate the antennas to reduce unnecessary power loss.
The proposed antenna was simulated in Ansys HFSS with the following results: the best value of S11 in the UHF band was -26.3dB, and the frequency range was 910~933MHz at -6dB; the best value of S22 in the GPS band was -10.86dB, and the frequency band was 1.558~1.602GHz at -6dB; the lowest value of S33 in the Wi-Fi band was -23.29dB, and the frequency range was 2.4~2.495GHz at -6dB. In the measurement part, the best value of S11 in the UHF band was -13.4dB, and the frequency range was 908MHz~928MHz at -6dB; the best value of S22 in the GPS band was -12.6dB, and the frequency band was 1.568GHz~1.59GHz at -6dB; the lowest value of S33 in the Wi-Fi band was -22.3dB, and the frequency range was 2.4GHz~2.485GHz at -6dB.The overall size of the proposed antenna is only 50x50x0.8mm3 and the multi-port structure is extremely suitable to be placed on small UAVs to provide the required frequency band for communication with ground stations.

摘要......i
Abstract......iii
誌謝......v
目錄......vi
表目錄......viii
圖目錄......ix
第一章 緒論......1
1.1 前言......1
1.2 研究動機與目的......2
1.3 內容提要......3
第二章 文獻回顧......4
第三章 無人機天線介紹與天線原理......10
3.1 無人機天線需求......10
3.1.1 數據傳輸天線......10
3.1.2 衛星定位天線......11
3.1.3 飛行控制天線......12
3.2 反射係數與S參數......13
3.3 天線隔離度(Antenna to antenna isolation)......15
3.4 天線輻射場型與增益......16
第四章 整合型天線設計......18
4.1 天線設計......18
4.1.1 UHF天線設計......20
4.1.2 GPS天線設計......21
4.1.3 Wi-Fi天線設計......23
4.1.4 天線尺寸......24
4.2 天線參數掃描分析......26
4.2.1 接地面槽孔寬度之頻率掃描分析......26
4.2.2 UHF天線之頻率掃描分析......28
4.2.3 GPS天線之頻率掃描分析......30
4.2.4 Wi-Fi天線之頻率掃描分析......32
4.3 天線模擬分析......35
4.3.1 天線模擬S參數分析......35
4.3.2 天線模擬場型分析......38
4.4 量測結果......45
第五章 結論......55
5.1 結論......55
參考文獻......57
Extended Abstract......60

[1] W. H. Weedon, W. J. Payne and G. M. Rebeiz, "MEMS-switched reconfigurable antennas," IEEE Antennas and Propagation Society International Symposium. 2001 Digest. Held in conjunction with: USNC/URSI National Radio Science Meeting (Cat. No.01CH37229), 2001, pp. 654-657 vol.3, doi: 10.1109/APS.2001.960181.
[2] M. Nosrati, A. Jafargholi, R. Pazoki and N. Tavassolian, "BroadBand Slotted Blade Dipole Antenna for Airborne UAV Applications," in IEEE Transactions on Antennas and Propagation, vol. 66, no. 8, pp. 3857-3864, Aug. 2018, doi: 10.1109/TAP.2018.2835524.
[3] J. Chen, K. Tong and J. Wang, "A triple band arc-shaped slot patch antenna for UAV GPS/Wi-Fi applications," 2013 Proceedings of the International Symposium on Antennas & Propagation, 2013, pp. 367-370.
[4] A. Sharma, I. J. G. Zuazola and A. Perallos, "Multipurpose Near- and Far-Field Switched Multiband Coil Antenna for 915-MHz/2.45/5.8-GHz RFIDs," in IEEE Antennas and Wireless Propagation Letters, vol. 16, pp. 2562-2565, 2017, doi: 10.1109/LAWP.2017.2733160.
[5] J. Chen, J. Wang, K. Tong and A. Al-Armaghany, "A dual band dual polarization slot patch antenna," 2017 IEEE International Conference on Computational Electromagnetics (ICCEM), 2017, pp. 34-35, doi: 10.1109/COMPEM.2017.7912803.
[6] Zebiri, C.; Sayad, D.; Elfergani, I.; Iqbal, A.; Mshwat, W.F.A.; Kosha, J.; Rodriguez, J.; Abd-Alhameed, R., " A Compact Semi-Circular and Arc-Shaped Slot Antenna for Heterogeneous RF Front-Ends, " Electronics 2019, 8, 1123.
[7] K. Wang, L. Li and T. F. Eibert, "Compact three-port printed diversity array with combined antenna types," 2014 IEEE Antennas and Propagation Society International Symposium (APSURSI), 2014, pp. 488-489, doi: 10.1109/APS.2014.6904575.
[8] L. Zhao, A. Chen, J. Zhang, S. Zheng and Y. Yin, "A single radiator with four decoupled ports for four by four MIMO antennas and systems," 2017 IEEE International Symposium on Antennas and Propagation & USNC/URSI National Radio Science Meeting, 2017, pp. 1659-1660, doi: 10.1109/APUSNCURSINRSM.2017.8072872.
[9] P. Cheong, K. Chang, W. Choi and K. Tam, "A Highly Integrated Antenna-Triplexer With Simultaneous Three-Port Isolations Based on Multi-Mode Excitation," in IEEE Transactions on Antennas and Propagation, vol. 63, no. 1, pp. 363-368, Jan. 2015, doi:10.1109/TAP.2014.2364299.
[10] D. Seo, J. Kim, M. M. Tentzeris and W. Lee, "A Quadruple-Polarization Reconfigurable Feeding Network for UAV RF Sensing Antenna," in IEEE Microwave and Wireless Components Letters, vol. 29, no. 3, pp. 183-185, March 2019, doi: 10.1109/LMWC.2019.2897479.
[11] H. Liu, M. Shi, S. Fang and Z. Wang, "Design of Low-Profile Dual-Band Printed Quadrifilar Helix Antenna With Wide Beamwidth for UAV GPS Applications," in IEEE Access, vol. 8, pp. 157541-157548, 2020, doi: 10.1109/ACCESS.2020.3018906.
[12] N. Neveu et al., "Miniature Hexaferrite Axial-Mode Helical Antenna for Unmanned Aerial Vehicle Applications," in IEEE Transactions on Magnetics, vol. 49, no. 7, pp. 4265-4268, July 2013, doi: 10.1109/TMAG.2013.2242870.
[13] K. Kurokawa, "Power Waves and the Scattering Matrix," in IEEE Transactions on Microwave Theory and Techniques, vol. 13, no. 2, pp. 194-202, March 1965, doi: 10.1109/TMTT.1965.1125964.
[14] "IEEE Standard for Information technology--Telecommunications and information exchange between systems Local and metropolitan area networks--Specific requirements Part 11: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) Specifications," in IEEE Std 802.11-2012 (Revision of IEEE Std 802.11-2007) , vol., no., pp.1-2793, 29 March 2012, doi: 10.1109/IEEESTD.2012.6178212.