序列饋入圓極化背接金屬共平面波導槽孔天線陣列之孔徑效率與正交極化改良

Abstract

背接金屬共平面波導槽孔天線具有高增益的特性，屬於線性極化天線。根據序列轉動饋入法，一個具有圓極化效果的陣列，可以由線性極化的天線來構成。因此背接金屬共平面波導槽孔天線適用於此理論，可以構成圓極化陣列。在本論文中，吾人利用此理論去達成圓極化效果，並且增加線性極化天線的個數以達成效能之改良。直播衛星收發天線運用在12 GHz的頻段，要求高增益與高效率。本論文研究遂將此圓極化天線的操作頻率設計在該頻段上，最後可得26.12 dBiC的輻射增益以及1GHz的圓極化軸比3 dB頻寬。

The slotted conductor-backed coplanar waveguide antenna features high gain, and belongs to linearly polarized antenna. According to the sequential rotation feeding method, a circularly polarized array can be composed of linearly polarized elements. Therefore, the slotted conductor-backed coplanar waveguide antenna is applicable to this theory, and can compose a circularly polarized array. In this thesis, we use the technique to produce circular polarization, and improve the performance with more linearly polarized elements. The antenna for direct broadcast from satellites (DBS) is operated at 12 GHz and asked for high gain and efficiency. We design our antenna to operate at this frequency. Finally, we have the measured radiation pattern with 26.12 dBiC and the measured axial ratio 3 dB bandwidth with 1 GHz.