- 學位論文
接地防護線之電氣特性與降低串音雜訊設計
Electrical Characteristics of Guard Traces and Design Schemes of Crosstalk Noise Reduction
摘要
在高速且高密度的數位電路中，研究串音效應的抑制方法，已成為最主要的信號完整度主題之一。其中，接地防護線越來越常被用來減緩由於電路佈線密集，所引發的串音雜訊干擾。 在本論文中，首先利用去耦合的模態進行微帶線上的防護線效應分析。防護線上的接地連通柱彼此之間會互相耦合引發共振現象，在鄰近線段上感應出振鈴雜訊，此現象經由去耦合的模態分析可以得到振鈴雜訊的量化分析。接下來，分別針對不同的介電常數與基板厚度，分析電容與電感耦合量的變化趨勢，並且與相對應的近端和遠端串音模擬波形比較，進行耦合傳輸線在雙層介質的環境中振鈴雜訊抑制的研究。並利用實驗量測數據，以驗證模擬分析結果。 最後將防護線設計，應用在差模傳輸線的串音效應抑制，延伸到改善差模蛇形延遲線的TDR與TDT波形的信號完整度及延遲時間偏差的問題。然而，防護線置入耦合傳輸線間會造成阻抗不匹配，因此提出縮小傳輸線寬的改善方法，避免阻抗不匹配帶來得反射損耗。並且經由比較置入防護線以及縮小線寬後，對於眼圖的改善程度，根據分析的結果提出適當的設計準則。
並列摘要
In the high-speed and high-density digital circuits, the problem of crosstalk-noise reduction becomes one of the major signal integrity concerns. Among them, the guard traces are increasingly used to alleviate this problem as the dense interconnect layouts emerge. In this thesis, the effect of a guard trace for the signaling transmission in a microstrip line is first analyzed from a multi-modal point of view. A multi-modal analysis allows a simple interpretation of the phenomena involved the ringing noise due to the resonance of shorting pin on a guard trace. Subsequently, the ringing-noise reduction for coupled-interconnect structures in a double-layered structure of varying dielectric constant and substrate thickness is investigated by calculating the capacitive and inductive couplings and analyzing the simulated near-end and far-end crosstalk waveforms. Additionally, the experimental results are presented to compare with and demonstrate the time-domain simulations of crosstalk reduction designs as proposed. Furthermore, using the guard traces to avoid the coupling between the differential pairs and to improve the signal integrity of TDR and TDT responses and timing skew of differential-serpentine delay-lines is performed in this thesis. However, the characteristic impedance of differential pair is decreased after guard trace is inserted between coupled transmission line sections. The impedance compensation can be achieved by shrinking the signal trace to avoid the reflection loss owing to impedance mismatch. According to the result of eye-pattern analysis, the proper design method is proposed in this thesis.