臺灣博碩士論文加值系統

本論文以車體本身金屬透過數位廣播(Digital audio broadcasting, DAB)的電源線，和DAB接地面連結，形成一個特殊型態的偶極天線結構，因為將整體視為一個天線，所以就不需要額外的外裝天線。利用L型網路當作此天線的匹配電路，再加上二極體開關，使此匹配電路可切換電感和電容值，在不同頻帶達到阻抗匹配。最後完成一包含4個電感、3個的電容及7個二極體開關的匹配電路。量測結果在DAB頻帶，都可使天線的S_11降至-10 dB以下，DAB天線的極化為垂直極化，觀察了X-Y平面的垂直極化，發現此架構輻射場型並非一般車用天線具有全向性。

In this thesis, a metallic car body is connected to the DAB ground plane with a power line to form a special dipole antenna. Regarding car metal as an antenna, so don’t need additional antenna structure. By using L-matching network to match the antenna, the inductance and capacitance can be switched to different values by diode switches, achieving impedance match at different frequencies. Finally, a matching network consists of 4 inductors, 3 capacitors and 7 diodes were designed and fabricated. The measured results show that the S_11 are all lower than -10 dB in DAB frequency range. The polarization of DAB antenna is vertical polarization. According to the vertical polarization on X-Y plane, radiation pattern is not omnidirectional as the general car antenna.

摘要 i
Abstract ii
致謝 iii
目錄 iv
圖目錄 vi
表目錄 x
第一章 緒論 1
1.1 前言 1
1.2 研究動機與背景 2
1.3 研究目標 3
1.4 章節概要 3
第二章 架構設計 5
2.1 概論 5
2.2 設計流程 6
2.3 整體架構設計 7
2.3.1 L-matching匹配 9
2.4 二極體參數萃取 13
2.5 匹配電路設計 17
2.5.1 理想開關 18
2.5.2 二極體開關 19
2.5.2.1二極體探討 20
2.5.3 加入直流隔離器和射頻扼流器 25
2.6 HFSS模擬 29
2.6.1 元件參數萃取 31
2.6.2 模擬結果 38
第三章 實際量測 55
第四章 結論 67
4.1 結論 67
4.2 未來展望及檢討 68
參考文獻 69

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