自我雙工之圓極化槽孔天線

Self-Diplexing Aperture for Dual-Sense Circular Polarization Operations

賴昱翰(Yu-Han Lai)

指導教授 ： 林怡成

國立臺灣大學/電機資訊學院/電信工程學研究所/碩士(2013年)

https://doi.org/10.6342/NTU.2013.11193

摘要

本論文探討具有自我雙工功能之圓極化天線設計，分別提出了兩個槽孔型之設計，一為單槽孔型，另一為雙槽孔型。除了實作與量測之外，文中也針對天線參數做模擬分析，以了解其輻射機制。本論文兩種設計皆是利用微帶線饋入之指數型槽孔的平面化設計；由饋入點激發出的電流會沿著槽孔邊緣行進，同時以漏波形式達到圓極化的輻射。與共振型圓極化天線相比，本文所採用的行波型指數曲線槽孔天線設計擁有更寬頻的圓極化特性與輸入阻抗。而相較於一般的雙頻天線，本論文之自我雙工天線因不需額外使用雙工器 (diplexer)，故有降低損耗且節省成本的優點。本論文兩種設計中，其相鄰饋入的雙埠皆擁有良好的隔離度。本文中的單槽孔型自我雙工圓極化天線，其高低頻雙埠的極化方向互為相反 (一為左圓極化，另一為右圓極化)；而進一步改進的雙槽孔型自我雙工圓極化天線，則可任意調整高低頻雙埠之極化方向，並不須限定同向或相反圓極化。在實際應用的考量上，本文最後將單槽孔與雙槽孔之自我雙工圓極化天線設計在無線區域網路 (WLAN, wireless local area network) 頻段之應用，其低頻頻段為2.4 ~ 2.5 GHz，而高頻頻段為5.15 ~ 5.9 GHz，經原型製作與量測結果顯示，其設計模擬與量測結果相當吻合，驗證本論文所提出設計方法之可行性。

關鍵字

槽孔天線 ； 圓極化 ； 雙頻 ； 雙極化 ； 自我雙工 ； 行波天線

並列摘要

This thesis presents two designs of self-diplexing aperture antenna for dual-sense circular polarization operations. One is the single-aperture type and the other is the dual-slot type, both with the same planar microstrip-fed design. We performed parametric studies and simulated the current distribution in order to understand the CP radiation mechanism. In general, an exponentially curved aperture antenna of traveling-wave type has a wider CP bandwidth compared to a resonant type antenna. With the diplexer embedded design, the proposed antennas can directly provide two ports of high-band and low-band operation with decent isolation. Hence, the diplexer may be effectively removed, leading to the reduction of cost, area, and loss. In this thesis, the single-aperture type self-diplexing CP antenna operates with an opposite senses of circular polarization in two bands. However, for the dual-slot type self-diplexing CP antenna, the dual senses at the two ports can be arbitrarily configured. Finally, we verified the design concept through the developed prototypes for WLAN applications, which operates 2.4 ~ 2.5 GHz for the low band and 5.15 ~ 5.9 GHz for the high band, respectively.

並列關鍵字

aperture antenna ； circular polarization ； dual-frequency ； dual-sense ； self-diplexing antenna ； traveling-wave antenna

參考文獻

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