共面波導非對稱饋入槽孔天線

Abstract

近年來，有相當多使用共面波導饋入天線的探討及應用，使用此種方式饋入的天線擁有相當多好處，例如：方便製造、成本便宜、方便與主動元件整合等…，在現今提出的結構中大部分都是對稱式的結構，較少採用非對稱式共面波導來饋入。本文提出一種非對稱饋入天線，利用共面波導的兩個槽孔，只要適當地調整其長度與阻抗使其滿足天線所需的共振條件，可使兩個槽孔天線獨立設計。 本文中，使用上述概念提出一種共面波導饋入的非對稱式寬頻槽孔天線，並對其結構做探討，經過適當的調整長度與阻抗匹配，可以得到相當寬頻的天線。由於結構主要是槽孔偶極天線構成，其輻射場型在某一平面相當均勻分散於空間，非常適合於行動通訊使用。同時，我們對原寬頻槽孔天線結構加入一寄生槽孔，得到一個可以滿足現今常用的行動通訊頻段的多頻天線。 上述所有提出的理論、應用、天線的實作及天線的實驗驗證，都會在本論文 一一地探討。

A slot antenna asymmetrically fed by a coplanar waveguide is proposed. The antenna is formed by using the two slotlines of the coplanar waveguide and modifying the slotline lengths and characteristic impedances appropriately to satisfy the resonant conditions of the slots. The two slots reformed can be controlled and designed separately and individually. Base on the above concept, a wideband asymmetric slot antenna fed by a coplanar waveguide is designed. The wideband nature is obtained by carefully choosing the slot lengths and impedances. Since the antenna structure is composed of simply the slot dipoles, the radiation pattern of the antenna is therefore omni-directional, which is very suitable for wireless communication applications. Another multi-band antenna design is achieved by adding a arasitic slot to the original design so that most of the commonly used wireless communication bands are covered. The antenna design methodology, simulations, and experiments are presented and discussed.