在本篇論文中，我們討論了多層印刷電路板可能會遇到的問題，因此我們設計了一個四層印刷電路板當作參考板來當作研究基準，並且藉由所設計的導通孔籠結構且適當的應用電容來解決這些問題。
訊號在傳統四層印刷電路板傳遞時，訊號線相應的電源層與地層是不相連的，所以會讓電流的回流路徑受阻，影響到訊號的穿透量，此外當訊號經過導通孔時，會產生一個相應的磁場，當這磁場波散出去時會影響到附近電路，也會在空間中反射，造成嚴重的干擾問題。
為了解決訊號在多層印刷電路板傳遞時所衍生出的問題，我們先是設計了導通孔籠結構，並且變換隔離環的分佈位置使其分成三種不同的結構，我們可以發現從約4.7 GHz開始，這三種結構都可以改善近端串擾與遠端串擾，從約-20 dB降至-35 dB左右，而在訊號的反射跟穿透則是不影響，證明此改善結構不會影響到訊號的傳遞，而在輻射的損耗三者結構的輻射量最大值都是低於參考板的，其中三者最大值約為54%，而眼圖的結果也都顯示三者結構對於訊號的品質沒有什麼負面的影響。
為了更進一步改善前面所設計的導通孔籠結構，我們應用去耦合電容來達成目的，在維持原有的訊號完整性的同時，更進一步的改善近端串擾與遠端串擾，從實驗結果可以知道，電容應用於成對隔離環交替分佈在電源層以及地層結構的表現最佳，此方法增加了低頻頻帶的抑制效果，近端串擾與遠端串擾從0 GHz到10 GHz都有著明顯的改善，對比參考板從-20 dB降至-40 dB以下，而在訊號的反射與穿透方面，抑制了導通孔所散發出的雜訊干擾之後，獲得了更好的反射量與穿透量，原本共振的情況也得到改善，在輻射量的表現也改善了許多，在2 GHz之前幾乎沒有輻射量，輻射量整體最大值約為40%，從眼圖也可以發現此方法讓訊號的品質得到提升，眼高、眼寬跟抖動都有良好的表現。

In this thesis, in order to understand the problems that may be encountered in multi-layer printed circuit boards, a reference four-layer printed circuit board is designed as a research benchmark. By utilizing the via-cage structure with the decoupling capacitors, these problems can be effectively solved.
When the signal is transmitting on the traditional four-layer printed circuit board, the corresponding return current on the power plane is disconnected to the return current on the ground plane since the power plane and the ground plane are disconnected. As a result, the reflection of the signal will be increased and the transmission of the signal will be decreased, degrading the signal integrity of the signal. Besides, when the signal penetrates through the via, a corresponding magnetic field will be generated and scattered, affecting the nearby circuits. Furthermore, the scattered magnetic field will be reflected back and forth between the power plane and the ground plane, causing serious interference problems.
In order to solve the problems caused by the signal transmission in the multi-layer printed circuit boards, three via-cage structures, whose anti-pads are designed wholly on the power plane, evenly on the power plane and the ground plane, and alternately on the power plane and the ground plane, are proposed. The three structures can reduece the near-end crosstalk and the far-end crosstalk from -20 dB to -35 dB above 4.7 GHz, while the reflection and transmission coefficients of the signal are maintained. Besides, the maximum radiation loss of the three structures is about 54%, which is lower than that of the reference board. Furthermore, the three structures will not degrade the eye diagram, ensuring the signal integrity of the structure.
In order to enhacne the performance of the via-cage structure, the decoupling capacitor is adopted. The signal integrity is further improved while the near-end crosstalk and far-end crosstalk are further reduced. From the experiment results, the via-cage structure, which applies the capacitors on the pair of alternately anti-pads distributed on the power plane and the ground plane has the best performance. The structure can suppress the near-end and far-end crosstalk noises in low frequency range. In contrast to the reference board, the near-end and far-end crosstalk noises are significantly reduced from -20 dB to -40 dB from 0 GHz to 10 GHz. As for the reflection and transmission of the signal, since the emission from the via is reduced, the reflection and transmission coefficients are improved. Besides, the performance of radiation loss has also been improved obviouly. Before 2 GHz, there is almost no radiation loss, and the maximum radiation is about 40% from 0 GHz to 10 GHz. It can also be found that the performance of eye height, eye width, and jitter are better as compared with those of the reference board, showing that the signal integrity is upgraded.

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Structure ” master’s degree thesis.