高功率低通濾波器與寬頻巴倫之設計與合成

Abstract

本論文前半部為設計一個以集總式元件來實現的低通濾波器，因其具有高功率規格的限制條件，故本文特別著重於材料與元件的選取，並且提出一些相關的設計技巧和判斷條件，作為實作此高功率低通濾波器的重要依據，詳細的製作流程和測試報告亦會在本文中討論。 本論文後半部為設計一個以高介電係數的雙面印刷電路板製程，並且使用微帶線、槽線、共平面帶線等多種混合式的傳輸線架構來實現一個寬頻的五階巴倫電路，此外，本文提出一個藉由理查轉換的直接精確合成方法，推導出巴倫在理查頻域的等效電路，並且利用柴比雪夫多項式來定義完整的數學方程式，求出其合理與可實現的聯立解，根據這個方法，我們可以任意設計所想要達成的巴倫特性與響應參數。

This thesis includes two parts. In the first part, we propose a high-power low-pass filter using all lumped components. According to the specifications of the product, suitable choice of materials and components is the most important issue for high-power consideration. Many useful tips will be introduced to estimate the filter performance and the detailed manufacturing process of this product will also be mentioned. In the second part, based on the exact synthesis method by Richard’s transformation, we present a new novel broadband balun structure, which can extend the conventional fourth-order Marchand balun to the fifth or higher order. For practical fabrication, some types of transmission-line structures can be used to implement the network such as microstrip line (MS), slotline (SL) and coplanar stripline (CPS). Most importantly, we can arbitrarily design the parameters of balun such as impedance transformation ratio, bandwidth and return loss by solving these established mathematical equations.