共面波導饋入槽孔型天線負載C環形結構之微型化與雙頻帶設計

Abstract

本論文針對負載C環形結構之槽孔型天線的特性做分析及探討，並以共面波導饋入分別實現微型化與雙頻帶之天線設計。首先，提出槽孔型天線在負載C環形結構下的等效電路模型，並與全波模擬的結果相互比較及驗證。此電路模型可解釋槽孔型天線在負載C環形結構下的共振機制，並歸納出降頻的主要要素。再者，就等效電路模型所得之結論，提出兩種槽孔型天線的微型化設計。最後，結合正向與反向兩種C環形結構達到槽孔型天線的雙頻帶設計，其特色是除了對低頻具有縮小效果外，亦可在不改變整體槽孔尺寸下，調整高低頻比，並可對單一頻率微調，且在兩頻帶內具有一致的輻射場型與低交叉極化。

In this thesis, the characteristic of the slot antenna loaded with C-shaped rings is analyzed and investigated. Two designs of miniaturization and dual-band operation are proposed for CPW-fed slot antennas . Firstly, the equivalent circuit model of the slot antenna loaded with C-shaped rings is presented. The computed resonant frequencies from equivalent circuit model are compared with full-wave simulation for verification. The verified circuit model is then utilized to explain the mechanism of the structure, with key factors of miniaturization discussed. Secondly, two different configurations of miniaturized slot antennas are presented. Finally, the dual-ring loaded slot antenna combining the original C-shaped ring and inverted C-shaped ring for dual-band operation is presented. In addition to size reduction, adjustable frequency ratio under the fixed antenna size are also achieved. The radiation patterns of both bands are almost the same, with low cross-polarization.