本論文將針對不同應用之射頻辨識讀取器天線、被動式金屬標籤天線以及波束合成饋入網路進行研究及設計。首先，為了提升讀取器陣列天線於遠場應用之增益或效率，乃利用較高寬長比之微帶天線或設計串聯饋入式網路來達成目標。其次，在近場讀取辨識方面，則運用矩形空腔來有效聚集微帶天線於近場之電場分佈，並且設計一個特定相位輸出之饋入網路來輔助電場集中效果，藉以提高近場通訊之電子標籤辨識率。
在被動式金屬標籤天線設計方面，本論文乃以槽孔天線的形式來加以實現，其無需額外之匹配電路即可達到與IC阻抗共軛匹配。另外，由於槽孔天線的電場主要分佈於槽縫中，因此將可大幅降低標籤附著物之金屬表面對於標籤天線輻射體的影響。
另ㄧ方面，關於智慧型天線所需之波束合成網路，本論文亦應用4×4巴特矩陣架構來設計之，並配合一般/新型式非對稱的人工傳輸線以及本論文所提出的交叉跨線來微型化電路尺寸。本文設計了兩款4×4巴特矩陣電路，其尺寸跟傳統4×4巴特矩陣相較之下，分別僅為5.7%以及4.8%。

In this thesis, some useful reader antennas, passive metal tag antennas and beam forming feed networks for various radio frequency identification (RFID) applications are carefully investigated and designed. Firstly, to flexibly enhances the gain or efficiency of the reader antenna, a much wider microstrip antenna or a series feed network is employed to help of an array antenna design for far-field operation. On the other hand, in order to gather the RF energy for near-field application, a rectangular cavity and a particular phase feed network also have been used to enhance electric field distribution for reader antenna design. Thus a better performance of tag identification can be achieved for near-field communications.
Moreover, a passive metal tag antenna to be mounted on a metallic object is also presented in this study. The tag antenna without additional matching circuit utilizes slot configuration to obtain a good conjugate match between the tag IC and antenna. Also, effects from metallic surface to the antenna may be reduced well due to electric field mainly concentrated within the slot.
This thesis also studies a smart antenna using 4 by 4 bulter matrix to achieve beam forming function, where the ordinary/newly asymmetric artificial transmission lines and proposed crossover are all employed to miniaturize circuit size. Compared with traditional 4 by 4 bulter matrix structure, the occupied dimensions of proposed two circuits are about only 5.7% and 4.8%, respectively.

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