利用六邊形週期性金屬貼片陣列合成倫柏格透鏡之天線設計

Abstract

現今，超材料這個主題已經被廣泛研究，其在諸多領域例如，光學，光子學，天線，感測，影像和光譜學等方面均具有很高的潛力。而由二維的週期性金屬貼片構成的超穎介面透鏡已曾被提出。超穎介面除了可以合成出多種於自然界中較難取得的材質特之外，相較於傳統的透鏡，此種實現的方法可以達到降低成本，節省空間效益與輕量化的目的。本文將倫柏格透鏡應用於表面波天線。 然而，在基礎理論的分析當中，大部分的問現都沒有提及關於波的傳遞方向之於週期性結構的色散關係市的探討。因此本文將提出另一種週期性的排列方式以合成倫伯格透鏡。首先，將波傳遞的方向考量帶進色散關係式加以分析。接著，透過比較兩種週期性排列的透進來驗證前面所提出的理論。除此之外，利用孔徑天線的特性定義出此天線的孔徑，並且將其表現透過各種效率的計算以達到特徵與量化的目的。除此之外，於文末將會提出一種新的合成方式改良作為表面波天線的表現。

Nowadays, research on metasurfaces has been widespread since the potential in several areas such as optics, photonics, antennas, sensing, imaging, and spectroscopy. The metasurface lens composes of 2D periodic metallic patch possesses several advantages such as light, low-profile, compact and also cheaper than the traditional lens array which practical implementation has been proposed. However, most of them didn’t mention the flaw of the wave propagating direction of dispersion characteristic when applying on metasurface lens’ synthesis. In this thesis, a Luneburg lens applies on surface wave antenna is proposed, further, two different types of unit cell will be compared, one varies significantly with the wave propagating direction, another does not, and analyze based on the dispersion characteristic. It will be verified by the performance of surface wave antenna composed of both unit cells. Several sub efficiencies of an aperture antenna used for characterization. Also, a novel synthesis will be presented to improve the performance of the lens’ surface wave antenna application.