本論文致力於面型微加工之微型可變電容之設計與模擬以獲得最佳化的元件幾何參數；另一方面，並進一步建立其等效電路模型以及進行相關之機電分析，例如：電場分佈、電荷分佈、共振頻率及pull-in電壓等分析。元件的基本結構是由一個上懸浮電極，以及兩個固定於基板上之底電極（分別為訊號電極與偏壓電極）所組成。元件是採用靜電力驅動方式，使上電極與偏壓底電極之間距產生變化進而調變訊號電極與上電極之電容值。為了增加電容調變率，本論文更進一步採用兩個不同電極間距之凹型結構設計。
高頻分析、等效電路分析與機電動態分析分別是利用Ansoft HFSS、Agilent ADS及IntelliSuite軟體進行模擬與分析，藉由這些模擬軟體可以在設計階段模擬出最佳化的元件參數。本研究所模擬的Q值與Pull-in電壓均與實際量測結果大致相符，證明本文所採用之模擬分析方法與所建立之等效模型是正確的。

This paper aims to design and simulate the surface-micromachining micro tunable capacitor for parameters optimization. This work also creates an equivalent circuit model of micro tunable capacitor and proceeds relative electromechanical analysis, including the distribution of field and charge, resonant frequency and pull-in voltage analysis. This micro tunable capacitor is constructed by one suspended top metal plate and two stationary bottom metal plates (one is signal electrode and the other one is bias electrode). By driving electrostatic force, the gap between top and bottom electrodes will be changed and results in a variation of capacitance. To increase the tuning range, the micro tunable capacitor with two different gap space will be presented in this research.
High frequency analysis, equivalent circuit analysis and electromechanical dynamic analysis are using Ansoft HFSS, Agilent ADS and the IntelliSuite software respectively. Through these simulation and analysis, it is possible to obtain the optimized specification of micro tunable capacitor. The quality factor (Q) and the pull-in voltage extracted by simulation software well match to the measured results; thus, the function of the analysis method and equivalent model adopted in this thesis can be demonstrated.

摘要 I
Abstract II
誌謝 III
目錄 IV
圖目錄 VII
表目錄 X
第一章 緒論 1
1-1 前言 1
1-2 文獻回顧 3
1-3 研究動機及目的 7
第二章 微型可變電容器之理論介紹 8
2-1 微型可變電容器操作原理 8
2-1-1 電容器之功用 8
2-1-2 傳統平行板電容器之原理 9
2-1-3 微型可變電容器之操作原理 10
2-2 微型可變電容器調變原理 13
第三章 微型可變電容器之設計、模擬與分析 17
3-1 建立模型之重要性 17
3-2 設計流程及方式 18
3-2-1 設計流程 18
3-2-2 設計平台 19
3-3 結構設計 21
3-4 等效電路模型分析 21
3-5 三維實體模型建立 25
3-6 模擬結果分析 28
3-6-1 共振頻率分析 28
3-6-2 高頻分析 34
3-6-3 電場分佈 39
3-6-4 電荷分佈 41
3-6-5 吸附的影響 43
3-6-6 應力的影響 46
3-7 光罩設計 47
第四章 結果與討論 50
4-1 微型可變電容器特性量測分析 50
4-1-1 電容效應 50
4-1-2 電感效應 55
第五章 結論與建議 57
5-1 結論 57
5-2 建議 58
參考文獻 59

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