近年來濾波器設計技術不斷推陳出新，雙頻帶與多頻帶之要求更為現今濾波器之重點。一般雙頻濾波器在設計時，會先設計出適合之雙頻諧振器，再針對兩頻帶所需之耦合量設計出適合的雙頻倒轉器。本論文以傳統濾波器合成理論為出發點，以兩種不同的濾波器合成方法，分別設計出等頻寬與不等頻寬之雙頻濾波器，並將電路以分佈形式實現。

首先利用頻率轉移函數，設計出具有等頻寬響應之雙頻集總元件濾波器，接著利用理想倒轉器將電路轉換，再使用四分之一波長開路殘段取代諧振器，將原本集總電路改成分佈形式，最後配合適當的雙頻倒轉器，將濾波器以微帶線實現出來。而在不等頻寬之雙頻濾波器電路設計方面，是利用複合諧振器之雙頻特性，但由於電路實現困難，因此本論文提出其對應之等效電路，據此將電路實現於分佈形式。最後論文針對此兩種濾波器電路進行設計模擬與實作量測，證明了方法之正確性。

In recent years, dual-band and multi-band filters design techniques keep emerging. Dual-band resonators and dual-band inverters are key blocks in these designs. In this thesis, two different synthesis methods are studied. One is for equal fractional bandwidth, and the other is for unequal fractional bandwidth.

Procedures for the first synthesis method include component parameters calculation by frequency transformation. Then the circuit configurations are modified by using ideal inverters. Finally the distributed circuit is implemented using microstrip lines, with the help of dual-band inverters. For unequal fractional bandwidth design, the second synthesis method uses composite resonators. Their equivalent circuits are derived to solve the realization problem. Then the filter is synthesized as a distributed circuit. To validate these methods, two dual-band filters have been designed, fabricated, and tested.

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