利用耦合/去耦合元件增加天線增益與隔離度之研究

Abstract

本論文中首先會介紹緊密放置的雙頻天線陣列中可使用之雙頻去耦合與匹配網絡的設計。依照[1]與[2]中所提出之概念，我們延伸設計了雙頻去耦合與匹配網絡。對較低頻段而言需要較長的傳輸線來完成去耦合電路。但這會佔用到較大的設計面積，所以在本論文中我們以慢波結構代替較長的傳輸線，並且可以有效降低使用面積。此外，我們利用截線負載諧振器去除較低頻中之虛部，達成去耦合目的。之後在網路端點接上雙頻匹配網路，讓輸入阻抗匹配。第二部分中介紹了用寄生元件增強微帶線天線之增益的方式。最後以模擬與實際量測方式驗證本論文中提出之方式。

In the first part of this thesis, a dual-band decoupling and matching network for a closely-spaced dual-band antenna array is presented. Using the concept of decoupling techniques in [1] and [2], we extend the network to dual-band decoupling structure. However, for the lower band, it is needed to use longer transmission lines, which is not possible to be built in a small area. Therefore, we also introduce the slow wave structure to act as a conventional transmission line, and effectively reduce the occupied area. Moreover, a stub-loaded resonator is employed in our design to decouple the lower band without any effect on the upper band. Then, a dual-band matching circuit is presented. In the second part of this thesis, use of parasitic elements on a microstrip patch antenna to enhance its radiation is investigated. The proposed techniques are verified with full-wave analysis and measurements.