三種創新設計的微帶線濾波器

Abstract

在本篇論文中，作者將針對現今微波帶通濾波器中，最主要的三種應用功能加以進一步的研究。此三方面包括:在平面電路板上分別實現寬頻、寬截止頻帶、微小型且具多傳輸零點的高效能濾波器。首先在寬頻濾波器方面，我們利用平行耦合三線結構與傳統的濾波器合成理論，推導出其等效的電路模型，並進而提出一套完整的設計流程。在寬截止頻帶濾波器設計方面，我們利用步階阻抗共振腔的共振頻可改變之特性，再配上擇定饋入法所產生的可調式傳輸零點，有效地將第一高階諧波控制至八倍的通帶中心頻處。最後我們提出堆疊式步階阻抗共振腔的濾波器架構，其特點為面積非常小且具多個可調傳輸零點。本篇論文將由各種的電氣特性及電路模型詳盡地討論各項濾波器特性，同時，還會提出多組的電路量測結果，以佐證理論的分析。

In this thesis, we aim at the improvement of three major applications of the modern microwave bandpass filters. Planar filters will be designed to have the wideband or wide stopband or compact size. First, the parallel-coupled three-line structure and the conventional filter synthesis theory will be employed to realize the wideband bandpass filter. Moreover, an equivalent circuit model will be also proposed to establish the complete design flow. For the design of the wide stopband filter, the stepped impedance resonators will be used to control the position of each spurious harmonic, and then, by using the tapped feeding, the higher-order harmonic will be pushed to above 8fo. Third, a very compact filter is realized by using the stacked-SIR. And the high selectivity will be also achieved by using several tunable transmission zeros. In this thesis, each electrical characteristic and the corresponding circuit model for each kind of the filter, will be detailedly discussed. Measurement results will be also provided to demonstrate the original idea.