交錯型複合式左右手傳輸線之圓極化漏波天線設計與分析

Abstract

此論文將分析交錯式的左右手傳輸線設計及分析圓極化天線應用，利用此傳輸線架構有以下優點：1.相較於傳統傳輸線，交錯型的架構會使我們有較大頻寬的輸入阻抗。 2.傳輸線為對稱且平衡之架構。 3.並可簡單及容易的方式調整到快波區間達到輻射效果。利用以上特性將能設計出寬頻圓極化漏波天線。 單一元件中會藉由輻射電場的強度及相位分析圓極化的特性，因此串接單一元件能迅速得設計出圓極化的漏波天線。為了使結構有較佳的對稱性，我們將針對側邊饋入及中間饋入設計立體balun的架構以接上不平衡之sma接頭，並探討影響S參數、增益以及軸比等設計參數。以上內容包含文獻探討、設計架構、輻射機制、模擬及量測的S參數和輻射場型。

This thesis presents a cross type (X-type) composite right/left-handed (CRLH) transmission line designed and analyzed for circularly polarized antenna applications. The X-type CRLH structures have several advantages, including the broadband input impedance, the symmetric and balanced structures, and the easy and simple implementation in the fast wave region for the leaky-wave antenna operations. By analyzing the unit cell of the antenna, a circular polarization (CP) property was achieved by designing the magnitude and phase of the two component of radiated E-fields. A CP leaky-wave antenna could be formed by integrating multiple segments of the unit cell. In order to feed the symmetric antenna structures, a folded balun feed is employed to convert the unbalanced SMA connectors to the balanced antenna ports, for both the center-fed and the edge-fed antenna. The thesis comprehensively covers the literature survey, the design of antenna geometry, the radiation mechanism, and the simulated and measured results of S-parameters and radiation patterns.