本論文第一部分提出一透地雷達研究，將6個寬頻的韋瓦第天線組成陣列，在近場範圍內進行目標物的偵測及成像。利用單元天線的頻率掃描反射訊號轉成時域訊號後，藉由時間軸平移的方式，將個別天線的回波訊號在近場範圍重組，可達到聚焦效果，獲得較明顯的目標物反射。透過網格資料庫和成像演算法，可在不同位置及環境介質裡進行目標物的成像。
第二部分提出以洛德曼陣列天線實現的訊號源定向系統。定向源演算法藉由洛德曼透鏡同時接收到的多個波束埠訊號，以振幅比較法來估測訊號源方向。本研究採用13個波束埠對6個天線埠的平面式洛德曼透鏡可實作於印刷電路板上，並放置於無反射實驗室進行輻射場型的驗證。此外亦放置於戶外空間進行訊號源定向量測實驗，以實測的訊號數據驗證定向演算法的效能。實驗結果顯示定向源系統具有精確的定向功能，其估測訊號源的角度誤差可達1度以內。

In the first part of this thesis, the proposed ground penetrating radar, which is consist of six broadband Vivaldi antennas, provides detection of target and the target's image in the near-field range. Reflection coefficient spectrum of each element antenna are used to derive the time domain reflection profile. The proposed beam focusing algorithm, which is based on a time-shift method, can enhance the target's reflection. By combining focused results at different locations, the radar system can produce the image that reveals the target location.
In the second part, an implementation of direction-of-arrival estimation algorithm using Rotman lens array antenna is proposed. The algorithm is based on a magnitude comparison method. The Rotman lens array provides multiple beam toward different directions simultaneously. The planar Rotman lens designed consists of 6 antenna ports and 13 beam ports. The prototype was fabricated with a printed circuit board. Array patterns is verified in a spherical near-field chamber, while the DoA algorithm was implemented offline using data taken from an open site. According to the experiment result, the estimation error of developed DoA system is less than 1 degree.

[1] D. M. Pozar, Microwave Engineering, 3rd ed, Wiley, New York, 2005.
[2] M. I. Skolnik, Introduction to Radar Systems, 3rd ed, McGraw-Hill, New York, 2001.
[3] J. J. Lee, S. Livingston, and R. Koenig, “A low-profile wideband (5:1) dual-pol array,” IEEE Antennas Wireless Propag. Letters, vol. 2, pp. 46–49, 2003.
[4] M. Uthansakul and M. Bialkowski, “Fully spatial wide-band beamforming using a rectangular array of planar monopoles,” IEEE Trans. Antennas Propag., vol. 54, no. 2, pp. 527–533, Feb. 2006.
[5] F. Soldovieri and R. Solimene, “Through-wall imaging via a linear inverse scattering algorithm,” IEEE Geosci. Remote Sens. Lett., vol. 4, no. 4, pp. 513–517, Oct. 2007.
[6] P. C. Chang, R. J. Burkholder, and J. L. Volakis, “Adaptive CLEAN with target refocusing for through-wall image improvement,” IEEE Trans. Antennas Propag., vol. 58, no. 1, pp. 155–162, Jan. 2010.
[7] R.J. Burkholder, and K.E. Browne, “Coherence Factor Enhancement of Through-Wall Radar Images, ” IEEE Antennas Wireless Propag. Letters, vol. 9, pp. 842-845, 2010.
[8] F. Sakai, A. Suzuki, O. Kazuo, M. Makimoto, and K. Sawaya, “A UWB through-wall radar using beam scanning array antenna, ” in Microwave Symposium Digest (MTT), 2011 IEEE MTT-S International, pp. 1-4, Jun. 2011.
[9] P. Protiva, J. Mrkvica, and J. Machac, “Estimation of wall parameters from time-delay-only through-wall radar measurements, ” IEEE Trans. Antennas Propag., vol. 59, no. 11, pp. 4268-4278, Nov. 2011.
[10] C.C. Chiu and W.T. Chen, “Electromagnetic imaging for an imperfectly conducting cylinder by the genetic algorithm [medical application], ” IEEE Trans. Microw. Theory Tech., vol. 48, no. 11, pp. 1901-1905, Nov. 2000.
[11] C.H. Chen, W.C. Hsiao, and C.C. Chiu, “Image reconstruction for the partially immersed conductor by dynamic differential evolution,” Communication Software and Networks (ICCSN), 2011 IEEE 3rd International Conference, pp. 433-436, 27-29 May. 2011.
[12] T. Hariyadi, A. Munir, A.B. Suksmono, K. Adi, and A.D. Setiawan, “Unidirec- tional broadband microstrip antenna for through walls radar application,” in Electrical Engineering and Informatics (ICEEI), 2011 International Conference, pp. 1-4, Jul. 2011.
[13] Y.J. Ren, C.P. Lai, P.H. Chen, and R.M. Narayanan, “Compact ultrawideband UHF array antenna for through-wall radar applications,” IEEE Antennas Wireless Propag. Letters, vol. 8, pp. 1302-1305, 2009.
[14] Y. Yang, Y. Wang, and A. E. Fathy, “Design of compact Vivaldi antenna arrays for UWB see through wall applications,” Progress In Electromagnetics Research, PIER 82, pp. 401–418, 2008.
[15] N.V. Venkatarayalu and Y.B. Gan, “Design of a tapered slot array antenna for UWB through-wall radar,” Antennas and Propagation Society International Symposium (APSURSI), 2010 IEEE, pp. 1-4, Jul. 2010.
[16] 涂雲從, 陣列天線波束寬度及傳播效能優化與平面線性掃描之毫米波天線量測場開發, 國立台灣科技大學電機工程研究所, 碩士論文, 民國102年.
[17] 廖文照,林志民, 先進電子偵測辨識及定位技術研究成果報告(完整版), 國科會專題研究報告(NSC96-2623-7-155-066-D), 國立臺灣科技大學, 2008.
[18] O. Kilic and R. Dahlstrom, “Rotman lens beam formers for Army multifunction RF antenna applications,” 2005 IEEE Symposium on Antennas and Propagation, vol. 2B, pp. 43-46, 2005.
[19] A. Lambrecht, S. Beer, and T. Zwick, “True-time-delay beamforming with a Rotman-lens for ultrawideband antenna systems,” IEEE Trans. Antennas Propag., vol. 58, no. 10, pp. 3189-3195, 2010.
[20] R. C. Hansen, “Design trades for Rotman lenses,” IEEE Trans. Antennas Propag., vol. 39, no. 4, pp. 464-472, 1991.
[21] D. H. Archer and M. J. Maybell, “Rotman lens development history at Raytheon Electronic Warfare Systems 1967-1995,” 2005 IEEE Symposium on Antennas and Propagation, vol. 2B, pp. 31-34, 2005.
[22] K. W. Cheung, H. C. So, W. K. Ma, and Y. T. Chan, “Least squares algorithms for time-of-arrival-based mobile location, ” IEEE Trans. Signal Process., vol. 52, pp. 1121-1130, 2004.
[23] N. Hao, R. Guangliang, and C. Yilin, “A TDOA location scheme in OFDM based WMANs, ” IEEE Trans. Consum. Electron., vol. 54, pp. 1017-1021, 2008.
[24] A. J. Weiss, “On the accuracy of a cellular location system based on RSS measurements, ” IEEE Trans. Veh. Technol., vol. 52, pp. 1508-1518, 2003.
[25] C. D. Wann and H. C. Chin, “Hybrid TOA/RSSI Wireless Location with Unconstrained Nonlinear Optimization for Indoor UWB Channels, ” in Wireless Communications and Networking Conference, 2007.WCNC 2007. IEEE, 2007, pp. 3940-3945.
[26] C. Li and Z. Weihua, “Hybrid TDOA/AOA mobile user location for wideband CDMA cellular systems,” IEEE Trans.Wireless Commun., vol. 1, pp. 439-447, 2002.
[27] R. T. Juang, D. B. Lin, and H. P. Lin, “Hybrid SADOA/TDOA mobile positioning for cellular networks,” Communications, IET, vol. 1, pp. 282-287, 2007.
[28] V. Y. Vu, A. J. Braga, B. Huyart, and X. Begaud, “Joint TOA/DOA measurements for spatio-temporal characteristics of 2.4 GHz indoor propagation channel,” in Wireless Technology, 2005. The European Conference on, pp. 47-50, 2005.
[29] J. D. Kraus and R. J. Marhefka, Antennas for All Applications, 3rd ed, New York, 2003.
[30] W. Rotman, R. Turner, “Wide-angle microwave lens for line source applications, ” IEEE Trans. Antennas Propag., vol. 11, no. 6, pp. 623-632, Nov. 1963.