電容、電感元件甚至是一段導線工作在高頻率時(>1GHz)，其電氣特性就與低頻時有所不同，因此用低頻集總元件設計的濾波器，在這射頻頻率之下，已經無法作精確的濾波設計。本篇論文詳細說明了，如何利用介入損耗方法來作射頻濾波器的原型設計，設計一微帶線帶通濾波器。接著利用平行耦合傳輸線的原理，並使用奇偶模解析解設計平行耦合帶通濾波器以實現原型之設計；並利用Ansoft公司之Serenade模擬軟體，模擬其頻率響應，並與實作結果比對。因為平行耦合帶通濾波器之尺寸太大，所以本論另外提出使用奇偶模分析之步階阻抗帶通濾波器來實現原型之設計，並作Serenade模擬與實作量測之比對。結果顯示本論文提出之射頻濾波器設計方法十分精確，所得之濾波器尺寸適用於無線通訊系統中。

When operating at high frequency ( >1GHz )，the electric characteristics of lumped capacitor and inductor components or even a conducting wire are totally different from the behavior at low frequency. Therefore, in the range of radio-frequency, using lumped elements to implement the filter designs will be very inaccurate. In this thesis, a RF band-pass filter prototype is designed by the method of insertion loss. Then, using the even and odd modes to analyze the coupled transmission lines, three coupled-line BPFs are proposed to implement the prototype design. The frequency responses of these coupled-line BPFs are simulated by Serenade and are measured by the vector network analyzer. Because the size of coupled-line BPF is too large for applying in the wireless communication systems, the stepped-impedance BPF is designed by the method of even and odd modes to implement the prototype design. The frequency responses of the stepped-impedance BPF are also simulated by Serenade and are measured by the vector network analyzer. The results show that the method of even and odd modes analysis to design RF filters proposed by this thesis is very accurate, and the size of implemented stepped-impedance BPF is small enough for applying in the wireless communication systems.

第一章 前言
1.1 背景介紹 ……………………………………………… 1
1.2 研究動機與目的 ……………………………………… 2
1.3 論文架構 ……………………………………………… 3
第二章 原理與分析
2.1 濾波器基本理論 ……………………………………… 4
2.2 微帶傳輸線 …………………………………………… 5
2.3 介入損耗法 ……………………………………………12
2.3.1 功率損耗比 …………………………………12
2.3.2 等漣波 ………………………………………13
2.3.3 等漣波低通濾波器原型電路 ………………13
2.3.4 低通濾波器轉帶通濾波器 …………………17
2.4 平行耦合線分析 ………………………………………19
2.4.1 奇偶模分析 …………………………………19
2.4.2 JK inverter ………………………………21
2.4.3 LC帶通電路轉換成平行耦合電路 …………23
2.4.4 耦合線之尺寸計算 …………………………29
2.5 步階阻抗濾波器原理 ………………………………33
2.5.1 傳輸線之Y函數特性 ……………………………34
2.5.2 步階阻抗濾波器Y矩陣推導 ……………………35
第三章 電路模擬
3.1 軟體介紹 …………………………………………43
3.2 平行耦合微帶線濾波器之設計模擬 ……………45
3.3步階阻抗微帶線濾波器 …………………………54
第四章 實作與量測
4.1 設計流程 ……………………………………………59
4.2 帶通濾波器之設計 …………………………………61
4.2.1 平行耦合微帶線之濾波器設計 ……………61
4.2.2 步階阻抗微帶線之濾波器設計 ……………64
4.3 實作與量測 …………………………………………66
4.3.1 平行耦合微帶線之濾波器實作與量測 ……66
4.3.2 步階阻抗微帶線濾波器之實作與量測 ……70
第五章 結論 ……………………………………………………72

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