平板電腦、智慧型手機與無線USB- Dongle等行動裝置平台上，一般需整合多種行動通訊協定，用以提供各式通訊應用。本篇論文中，提出三種適用於不同應用情境行動平台的內藏式天線設計。其設計目標除需滿足平台上的應用規格外，並希望能系統化的分析其設計原理。
新近之消費性電子產品，基於使用便利性與設計美學上等考量，多需要內藏式的天線設計。本論文第一款天線為內藏於平板電腦裝置並可支援LTE/WWAN頻帶的寬頻天線設計，該天線使用曲折型單極天線結構當做主輻射體，並輔以多分支架構、可貼附式的集總電路元件負载與加在主輻射體旁的寄生元件等技術，以達成所需的寬頻帶操作。利用上述設計，我們進ㄧ步設計出適用於具金屬保護框之大尺寸智慧型手機上的LTE 天線。該設計利用嵌入一個空氣間隙於天線的金屬保護框架上，達到減輕金屬遮蔽物在天線近場區域對天線阻抗匹配的影響，使該天線能支援WWAN與LTE頻段操作。
第二款為可應用於行動手持裝置內的新型可雙頻操作圓極化晶片天線設計，該天線可支援現有各式全球衛星定位系統的L1 與L2 頻帶應用。天線採用單極架構，需一足夠大的淨空區以確保其天線匹配，輻射效率與往天頂方向的右圓極化輻射場型。此外，我們亦改變晶片天線架構為平面式倒F型，可設計出一款不需任何淨空區，於L1頻帶操作的右圓極化天線。
第三款為一建置在USB Dongle平台上，可支援WLAN的雙頻帶解耦合雙天線系統。由於天線間距小而具有強耦合，因此，本論文開發出ㄧ個建置在天線結構上的解耦合機制。該機制包含一成對的微帶殘枝、一短槽線與一貼附於該槽線間的集總電容負載。並提出天線相關度與天線分集增益的評估方法。

Devices such as tablet PCs, smart phones, and wireless USB-dongle devices, play indispensable roles in mobile computing. Portable platforms, which integrate several wireless communication protocols, are required to provide broadband wireless connections to support various emerging applications. In this dissertation, three antenna designs applicable to portable platforms are presented. The goals are not limited to provide required performance, but also to devise a systematic way in designing compact antennas with tight spatial constraints.
Internal antennas have been widely adopted in consumer electronic products. An LTE/WWAN antenna design applicable to tablets is developed using parasitic elements, meandered structures, branched structures and a lump component. Above antenna geometry is also implemented on a smart phone with a metal frame. An air gap is embedded in the frame to mitigate performance deterioration.
Two novel compact circular polarization chip antenna designs are proposed. They can be installed on handsets. One is a monopole that covers both L1 and L2 bands of the global navigation satellite systems. The other, which requires no clearance region, is based on the PIFA structure and operates in the L1 band.
The third design provides a co-band two-antenna implementation in a compact USB-dongle platform. Novel decoupling techniques are proposed to enhance isolation among closely spaced antennas. They include a pair of stub on the antenna structure and a capacitive loading across a shorted slit on the ground plane. Operation in both WLAN bands is achieved. The envelope correlation coefficient and effective diversity gain observed are exceptional.

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