利用四分之一波長、準四分之一波長以及摺疊式四分之一波長諧振腔之微型化微帶線交錯耦合濾波器

Abstract

本論文提出利用四分之一波長、準四分之一波長以及摺疊式四分之一波長諧振腔之微型化微帶線交錯耦合濾波器。在論文的第一部分，我們提出將四分之一波長與準四分之一波長諧振腔適當的組合可以使濾波器的主耦合與交錯耦合產生不同的相位差，此方法可用來實現各種的交錯耦合濾波器，其中包括Cascade Quadruplet 濾波器與 Cascade Trisection濾波器。在論文的第二部分，本論文利用摺疊式四分之波長諧振腔來設計尺寸更小的交錯耦合濾波器，經由選擇不同的交錯耦合結構,達到實現不同濾波器響應的目的。本論文中也針對交錯耦合濾波器的響應提出新的解釋方法,我們分析濾波器主耦合路徑與交錯耦合路徑的相位關係，成功的預測交錯耦合濾波器的響應。本論文中所提出的濾波器皆經由實作驗證,量測結果與理論分析相當吻合。

This thesis presents the miniaturized microstrip filter using quarter-wave or quasi-quarter-wave or folded quarter-wave resonators. In the first part, we demonstrate that the combination of quarter-wave and quasi-quarter-wave resonators facilitates the cross coupling with a proper coupling phase. This enables various responses of the cross-coupled filter including Cascade-Quadruplet (CQ) or Cascade Trisection (CT) filters to be realized. In the second part, the cross-coupled filters using folded quarter-wave resonators are proposed. The filters are more compact and are able to realize different cross-coupled filter by proper selection of the cross coupling mechanisms including the electrical and the magnetic coupling. A new explanation of filter response that analyzes the coupling phase between the main coupling and cross coupling is proposed. Measurement results correlate well with theoretical predictions.