縮小型雙頻帶通濾波器之設計與實現

Design and Implementation of Compact Dual-Passband Filters

鄧智宇(Chih-Yu Teng)

指導教授 ： 毛紹綱

國立臺北科技大學/電資學院/電腦與通訊研究所/碩士(2007年)

https://doi.org/10.6841/NTUT.2007.00196

摘要

本論文提出新的雙頻帶通濾波器的設計方法，首先，分別利用低頻通帶與高頻通帶的頻率規格得到原始的雙頻共振器等效電路，再轉換成另一形式之等效電路，之後，利用阻抗匹配條件及相位與阻抗補償法以改善原始的λg/4導納反轉器，而達到任意兩通帶頻率比的雙頻濾波器設計。此設計方法之優點為不會產生直流通帶，且對於兩通帶之間的止帶亦可產生極低的拒斥響應。本研究以此設計原理，實際製作一雙頻帶通濾波器，並以分接線取代前後反轉器，使其寄生通帶受到抑制，在18 GHz之前寄生通帶之抑制可達到S21低於-25 dB，且將並聯殘段替換，使其縮小82.2 %。

關鍵字

雙頻帶通濾波器 ； 寄生通帶抑制 ； 尺寸縮小

並列摘要

In this thesis, a novel methodology of dual-passband filter design is presented. First, the conventional equivalent circuit of the dual-passband resonator is obtained by its frequency limits of lower and upper bands and then transformed into the equivalent one. Thereafter, the impedance matching condition and phase and impedance compensation are employed to improve λg/4 admittance inverters in order to acquire arbitrary frequency ratio design. The advantages of the design methodology are the elimination of DC passband and the deep rejection between two passbands. Based on the design methodology, a dual-passband filter is demonstrated. Its spurious passband is suppressed by replacing first and last inverters with tapped-lines. Consequently, over 25 dB spurious passband suppression is achieved. Furthermore, a 82.2 % size reduction is accomplished by substituting shunt stubs.

並列關鍵字

dual-passband filter ； spurious passband suppress ； compact size

參考文獻

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