弱耦合差模微帶線以45度角跨越其它差模信號線之共模雜訊抑制

Common-Mode Noise Reduction for Differential Lines Crossing Other Differential Lines at 45 Degree in a Weakly Coupled Microstrip Lines

洪學良(Syue-Liang Hong)

指導教授 ： 薛光華

中原大學/電機資訊學院/電子工程研究所/碩士(2015年)

https://doi.org/10.6840/CYCU.2015.00417

摘要

本論文提出與研究新的抑制方案，針對弱耦合差模微帶線以45度角跨越弱耦合差模埋入式微帶線結構。針對所提出的結構，使用3D全波模擬軟體HFSS與CST進行頻域與時域分析，藉由差模轉共模的模態和時域反射波型研究該結構的共模雜訊與反射雜訊。所提出的最新的抑制方案為相互跨越的區域為兩兩垂直並由弱耦合改為強耦合結構，最新的抑制方案降低典型的弱耦合差模微帶線以45度角跨越弱耦合差模埋入式微帶線結構的共模雜訊之峰對峰值約76%~97%，於頻域範圍約0.3GHz~16GHz的差模轉共模模態也有顯著地抑制典型的弱耦合差模微帶線以45度角跨越弱耦合差模埋入式微帶線結構，而相互跨越的差模傳輸線的差模阻抗仍然保持阻抗匹配。此外，使用所提出的改善方案於時域反射波型中有顯著地改善反射雜訊。最後，模擬結果與量測結果相互驗證本輪文所提出的改善方案能有效地抑制典型結構的共模雜訊與反射雜訊。

關鍵字

差分微帶線 ； 差分埋入式微帶線 ； 共模雜訊 ； 差模轉共模模態之轉換 ； 時域反射波形

並列摘要

This work proposes and investigates new noise reduction schemes for reducing CMN and reflection noise in a weakly coupled differential microstrip lines (WCDMLs) that crosses a weakly coupled differential embedded microstrip lines (WCDEMLs) at 45 degrees (also called a “conventional traces crossing structure”). Time- and frequency-domain analyses of the proposed schemes are performed to investigate and reduce the CMN and reflection noise by studying the differential-to-common mode conversion and the time-domain reflection (TDR) waveform using the 3-D full-wave simulator CST and HFSS. The proposed solutions reduce the peak-to-peak amplitude of the CMN in the conventional traces-crossing structure of weakly coupled differential lines, by approximately 76%~97% , while the differential impedances of the two crossing differential lines remain matched. The range of frequencies over which the magnitude of the differential-to-common mode conversions (Sc2d1, Sc4d3, Sc3d1, Sc1d3) are significantly reduced is very wide – about 0.3–16 GHz. Furthermore, the voltage drop (reflection noise) in the TDR waveform is greatly reduced using the proposed designs. Finally, a favorable comparison between the simulated results and measurements verifies the excellent CMN and reflection noise reduction performance of the proposed schemes.

並列關鍵字

Differential microstrip lines ； Differential embedded microstrip lines ； common-mode noise ； differential-to common mode conversion ； time-domain reflection waveform

參考文獻

[1]J. Fan, X. Ye, J. Kim, B. Archambeault, and A. Orlandi, “Signal integrity design for high-speed digital circuits: progress and directions,” IEEE Trans. Electromagn. Compat., vol. 52, no. 2, pp. 392-400, May 2010.

[3]C. R. Paul, Introduction to Electromagnetic Compatibility, 2nd. New York: Wiley, 2006.

[4]C. R. Paul, Analysis of Multiconductor Transmission Lines. NewYork,NY, USA: Wiley-Interscience, 1994.

[5]C. R. Paul, “Solution of the transmission-line equations under the weakcoupling assumption,” IEEE Trans. Electromagn. Compat., vol. 44,no. 3, pp. 413–423, Aug. 2002.

[6]W. Liu and Y. Kami, “Analysis of coupling between transmission lines in arbitrary directions,” Proc. 1998 IEEE EMC Symposium, pp.952-957, Denver, Aug. 1998.