由於電信產業中傳輸速率需求越來越高，差分線被廣泛應用在PCB 上進行訊號傳輸。為了保持好的訊號完整性，必須縮小相鄰差分線之間的串間干擾，以避免訊號失真。根據乙太技術路線2020，傳輸速率在未來十年內預計達到1.6TbE/800GbE，因此在有限的電路板面積下，設計差分傳輸線的尺寸大小變得非常重要。
為了克服這些挑戰，本研究提出一種以tab 形狀利用spoof surface plasmon
polariton 的特性建立差分傳輸線的方法。這種方法不需要增加額外的電路板面積，卻可以減少差分訊號傳輸線之間的串間干擾。
研究結果顯示，在頻率大於67.5 GHz 後，採用tab_2 差分對結構的遠端串擾低於傳統差分對結構，在目標80 G Hz 改善了1 dB，達到 12 dB，而在71 和93 GHz 相較於傳統差分線，都降低了16.5 dB 的遠端串擾，但距離在高頻傳輸線的遠端串擾目標 20 dB 還需要改善3.5 dB 左右。但從研究模擬解果意味著在頻率範圍67.5 至100 GHz 的高頻傳輸中，tab_2 週期性差分對結構確實符合研究的設想，相較於傳統差分對結構，在相同的間距下具有較低的遠端干擾。這有助於提高訊號傳輸的完整性並有效降低高頻傳輸下的串間干擾。
因此，本研究的主要貢獻在於提出了一種新的差分傳輸線結構，並通過模擬和比較分析證明了其在高頻範圍內具有較低的遠端串擾。這對於高頻電路和通訊系統的設計和性能優化具有重要意義。

As the demand for higher transmission speeds in the telecommunications industry continues to grow, differential lines are widely used on printed circuit boards (PCBs) for signal transmission. In order to maintain good signal integrity, it is important to minimize crosstalk between adjacent differential transmission lines to avoid signal distortion. According to the Ethernet technology roadmap for 2020 [1], transmission speeds are expected to reach 1.6 TbE/ 800GbE in the next decade, making it crucial to design differential transmission lines with appropriate dimensions within limited PCB space.

To overcome these challenges, this study proposes a method of establishing differential transmission lines using tab shapes and exploiting the characteristics of spoof surface plasmon polaritons (spoof SPPs). This approach does not require additional circuit board area but can reduce the crosstalk between the differential signal transmission lines.

The research results show that, after a frequency of 67.5 GHz, the tab_2 differential pair structure exhibits lower far-end crosstalk than the traditional differential pair structure. At the target frequency of 80 GHz, the far-end crosstalk is improved by 1 dB, reaching -12 dB. Additionally, at 71 and 93 GHz, the far-end crosstalk is reduced by 16.5 dB compared to the traditional differential lines. However, achieving the target far-end crosstalk of -20 dB at high-frequency transmission lines requires an improvement of approximately 3.5 dB.

Nevertheless, the simulation results suggest that the tab_2 periodic differential pair structure indeed fulfills the envisioned objectives in the frequency range of 67.5 to 100 GHz, as it demonstrates lower far-end interference than the traditional differential pair structure at the same spacing. This contributes to enhancing the integrity of signal transmission and effectively reducing crosstalk at high-frequency transmission.

Therefore, the primary contribution of this study lies in proposing a novel differential transmission line structure and demonstrating, through simulation and comparative analysis, its lower far-end crosstalk in the high-frequency range. This holds significant implications for the design and performance optimization of high-frequency circuits and communication systems.

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