應用於超寬頻無線通訊與脈衝雷達系統之寬頻天線的設計與分析

本論文中提出兩種應用於高寬頻通訊與脈衝雷達系統應用之線性極化與圓極化寬頻天線。首先提出一新型超寬頻天線由漸變環形天線與左右手共平面波導轉共面帶線轉接電路組成及研究此寬頻天線在時域與頻域上的特性。此天線的阻抗頻寬涵蓋3.1~10.6 GHz，且在操作頻率範圍下輻射場型近似全向性，具有3.3~7 dBi的天線增益。另外在漸變環形天線電路上外加對稱短路槽線設計達到5~6 GHz頻段的帶拒特性。在時域分析上，以天線的轉移函數與脈衝波形相似度計算出發射與接收天線在多重路徑傳播通道中的時域脈衝響應，此研究的天線電路具有寬頻及低脈衝失真的優點，對於超寬頻通訊的更具有適用性。論文第二的部份提出應用於雷達目標物位置與形狀偵測之新型脈衝雷達天線系統。此雷達帶測物的脈衝響應量測中，脈衝信號源以具有頻率波數掃描的輻射場型的寬頻右手圓極化微帶天線作激發，帶測物回波以寬頻左手圓極化螺旋天線為接收，由金屬帶測物表面產生的散射特性以雷達解析技術得到帶測物體位置與形狀的辨識結果。論文提出的辨識方式，由脈衝響應量測結果經由反卷積與幾何數學計算後，估測的金屬物體的位置與尺寸與實際物體可達到最少86%的相似度。相較於傳統雷達偵測系統，此新型脈衝雷達天線系統降低傳統雷達天線系統的電路複雜度且改善掃描費時等缺點，更提升雷達偵測以及雷達影像等應用效益。

關鍵字

寬頻天線；脈衝雷達；物體探測；寬頻圓極化天線；轉移函數；散射量測

並列摘要

In this dissertation, two pairs of novel planar wideband antennas with opposite polarization are presented for ultra-wideband communication and impulse radar system applications. A novel ultra-wideband (UWB) antenna which consists of a tapered loop radiator and a coplanar waveguide-to-coplanar stripline (CPW-to-CPS) transition is investigated in both frequency- and time-domain firstly. The antenna possesses a wide impedance bandwidth and shows similar radiation patterns and 3.3 to 7dBi peak gain from 3.1 to 10.6 GHz. Two additional short-circuited slots are symmetrically located on the tapered loop radiator to achieve the 5-6 GHz band-notched behaviors. The time-domain characteristic of the transmitting/receiving antenna system in multipath propagation channel is also described by antenna transfer function and examined by pulse fidelity. The proposed antennas with broad bandwidth and low pulse distortion are good candidate for UWB applications. Secondly, a novel impulse radar antenna system for the shape and position of single- and multi-object detections is investigated. In the radar object pulse response measurements, a broadband series-fed circularly polarized microstrip antenna (SFCPA) with frequency beam-scanning is excited an impulse waveform and which is received by a wideband micrstrip-fed circularly polarized spiral antenna. The object position and shape could be recognized from radar resolution technology and channel impulse response due to scattering field from object surface. After deconvolution and numerical calculation of the measured results, the estimated dimensions and positions of the metallic objects are exhibited the least 86% similarity with reality. The proposed radar antenna system improves the complexity of the conventional radar system and increases the efficiency of target detection in radar imaging applications.

並列關鍵字

Ultra wideband antenna ； impulse radar ； target detection ； broadband circularly polarized antenna ； transfer function ； scattering measurement

參考文獻

[1]J. H. Reed ed., An Introduction to Ultra Wideband Communication Systems, NJ : Prentice Hall PTR, 2005.

[2]H. Engler and Jr. F., “Advanced technologies for ultra wideband system design,” IEEE International Symposium, vol. 2, pp. 250 – 253, Aug. 1993.

[4]Aiello G.R and Rogerson G.D., “Ultra-wideband wireless systems,” IEEE Microwave Mag., vol. 4, pp.36-47, June 2003.

[5]J. Dederer, B. Schleicher, F. De Andrade Tabarani Santos, A. Trasser, and H. Schumacher, “FCC compliant 3.1-10.6 GHz UWB pulse radar system using correlation detection,” IEEE MTT-S, Int. Microwave Symp., pp. 1471-1474, June 2007.

[7]J. S. Tyo, E. G. Farr, and D. I. Lawry, “Effect of defocus on the prompt response of a reflector IRA,” IEEE Trans. Antennas Propag., vol. 53, pp. 3247-3254, Oct. 2005.

國際替代計量

應用於超寬頻無線通訊與脈衝雷達系統之寬頻天線的設計與分析

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