因應雷達技術平價化與新興應用擴展的趨勢，本論文針對可改變雷達目標物反射特性的結構進行研究。考量在安全防護應用中，如車用防撞雷達，對反射能力較弱的目標，如行人和道路障礙物，設計增強RCS的結構，以提升偵測距離與系統反應時間。而RCS增強結構設計，基本設想是採取平面化構型，以方便附加於目標物上。除了提升在車用雷達頻段的RCS增強效能，也要增加其有效的入射角度範圍。
本論文第一部份採用信號回授天線作設計，利用范艾達陣列天線能自動將入射的電磁波發射至來波方向特性，實現在目標頻段的RCS增強效能。第二部分提出一種改進式的單站雷達反射截面積量測方法，可在遠場無反射實驗室內進行，配合向量網路分析儀及相應的訊號處理方式，可計算出目標物之RCS值，並利用此方法量測一款於本研究中提出之RCS增強結構，探討其散射特性，經與模擬結果比較，驗證了該量測方法的準確性。本論文最後則是針對24 GHz車用雷達頻段進行RCS增強結構開發，提出兩款結合垂射與端射方向場型的貼片陣列天線，設計的兩款增強結構能對各角度的入射能提供強回波，達成寬角度的單站RCS增強效能。

The reduced cost and development of innovative radar application motivate the research works presented in this thesis. The goal is to design broad angle radar cross section enhancing structures, which are applicable to the automotive anti-collision avoidance radar and help improve safety of low retro-directive targets such as the pedestrians and bicycles. By elevating the radar cross section levels of those targets, detection distances can be increased to save some time for the automobile control system. In order to install the radar cross section enhancing structure on targets conveniently, planar designs are preferred. Also, the reflection boosting feature is desired for a broad angular region to avoid potential blind spots.
The first part of this thesis employs retro-directive antennas to achieve this goal. Owing to the distinctive property of Van Atta array, incident waves can be re-transmitted to the incoming direction without the uses of active components. Such a design is realized in the X-band.
The second part presents a measurement technique that improves the sensitivity of RCS measurement, which is performed in a far-field antenna measurement range. The range setup as well as the instrument settings are optimized to assess low RCS levels.
The last part designs a RCS enhancing structure in the 24 GHz band, which is applicable to automotive radar uses. Two types of patch antenna array are integrated to yield a broad angle RCS enhancing feature that meets the design goal of this work.

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