以耦合共振腔實現小型化枝幹耦合器之設計

Abstract

本篇論文的主題是一種由耦合共振腔組成的枝幹耦合器。四分之一波長傳輸線可以等效成共振腔之間的耦合。因此，傳統的枝幹耦合器可以轉變成一個耦合共振腔網路。使用這種方法合成的耦合器會具有帶通的特性。此外，耦合器的面積會隨著共振腔的縮小而減少，相較於傳統的枝幹耦合器，利用微小化共振腔設計的耦合器可以省下百分之五十的面積。 另外，這種方法也可以應用於設計雙頻的耦合器。配合步階式阻抗共振腔，可以得到一個具有帶通響應的雙頻枝幹耦合器。

This thesis presents compact branch-line couplers composed of coupled resonators. The quarter-wavelength transmission lines are equivalent to the couplings between resonators. Therefore, the conventional branch-line coupler can be transformed into a coupled-resonator network. The resultant coupler provides bandpass characteristics. In addition, the size of coupler reduces as the size of resonator shrinks. With miniaturized resonators, the coupler saves 50% of area compared with conventional branch-line coupler. Moreover, this technique can be applied to design dual-band couplers. With stepped-impedance resonators, a dual-band branch-line coupler with bandpass response is achieved.