針對多對差動訊號線之寬頻共模抑制濾波器設計

Wideband Common-mode Suppression Filter Design for Multi Differential Signal Pairs

鍾國俊(Guo-Jun Zhong)

指導教授 ： 林丁丙

國立臺北科技大學/機電學院/電腦與通訊研究所/碩士(2014年)

摘要

本論文主要目的為設計一應用於多對差動訊號線之寬頻共模抑制濾波器，此結構藉由在差動訊號線下方建立開四分之一波長開槽式接地結構來達到抑制共模訊號，且透過在開槽式接地結構中之四分之一波長共振器彼此間的耦合關係設計出較寬頻的共模抑制頻帶特性。並實現於印刷電路基板上所以具有價格低廉和製作簡易，且此設計架構應用於多對差動訊號線下仍保有寬頻共模抑制之等優點。在頻域分析中，在一對差動訊號線下其差模插入損耗從低頻到高頻皆能維持在-3 dB以上，而共模插入損耗，以-15 dB定義之下具有4.2 GHz的共模抑制頻寬。為了快速預測我們所提出的寬頻共模抑制濾波器架構之電器特性，因此建立出此開槽式接地結構於共模濾波之等效電路模型。然後根據模擬與實驗之結果可證明本文所提出開槽式接地結構共模濾波器，在多對的差動訊號線下能有效降低其共模雜訊的成分，同時還能維持良好的差模訊號完整性。最後，藉由量測眼圖和時域/頻域的共模雜訊的結果驗證本論文設計的寬頻共模抑制濾波器設計與分析。

關鍵字

共模濾波器 ； 開槽式接地結構 ； 四分之一波長共振器 ； 訊號完整性

並列摘要

In this thesis, we proposed a wideband common-mode suppression filter for multi differential signal pairs. The method of the proposed design is utilized by using defected ground structure (DGS) of quarter-wavelength resonators with the mutual coupling effect between the quarter-wavelength resonators to achieve the wideband common-mode suppression. The proposed structure is fabricated on printed circuit board (PCB) with low coast and simple manufacture. In multi differential signal pairs, we still have an advantage of a wideband common-mode suppression. For observing one pair differential signal lines in the frequency domain analysis, the differential-mode insertion loss are all above -3 dB from DC to 10 GHz. For the common-mode insertion loss, a wide common-mode suppression bandwidth is 4.2 GHz by using -15 dB definition. The equivalent circuit model of the proposed DGS resonators has also been constructed to predict the phenomenon of the common mode suppression. Then, the result shows a good agreement between simulation and measurement. The results indicate that the proposed common-mode filter has broadband operation on common-mode suppression and multi differential signal pairs. In addition, it can maintaining the good signal integrity of differential signal pairs. Finally, by measuring eye diagrams and frequency domain results validate Wideband Common-mode Suppression Filter Design for Multi Differential Signal Pairs.

並列關鍵字

common-mode filter ； defected ground structure(DGS) ； a quarter wavelength resonator ； signal integrity

參考文獻

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