為了探討彎曲差動傳輸線的差動彎角特性，我們採用一個集總等效電路來表示差動彎角。集總等效電路的元件值可以使用第二章所提的方法萃取。為了驗證集總等效電路，我們製作與量測一個九十度彎角的彎曲差動傳輸線。量測的結果顯示集總等效電路可以有效地表示這個彎曲差動傳輸線的九十度彎角。
為了消除差動彎角所產生的模轉換，我們在差動彎角的等效電路上加上補償電容以補償差動彎角的電容。此外，我們運用印刷電路板的製作技術，使用平行板電容實現這個補償電容。模擬與實驗的結果顯示使用補償電容的彎曲差動傳輸線可以大大地降低模轉換與接收端的共模雜訊，但是會增加發射端的差模雜訊。然而，使用平行板電容的彎曲差動傳輸線只能稍稍降低模轉換與接收端的共模雜訊，並且增加發射端的差模雜訊。由此可知，在差動彎角之內側增加平行板電容並無法有效的降低共模雜訊。此外，由於增加平行板電容將稍微減小眼圖的大小，因此訊號完整度會稍微降低。
為了有效的抑制差動彎角的模轉換，我們提出補償電感的方法以補償彎曲差動傳輸線的差動彎角。運用印刷電路板的製作技術，這個補償電感可以使用無截角及截角之尾端短路耦合線實現。模擬與量測的結果顯示使用補償電感與無截角及截角之尾端短路耦合線的彎曲差動傳輸線，可以大量地降低模轉換與接收端的共模雜訊，但是會增加發射端的差模雜訊。此外，使用無截角及截角之尾端短路耦合線的彎曲差動傳輸線可以維持甚至改進訊號的完整度。
最後，我們進ㄧ步提出平衡式模型以降低接收端的共模雜訊與發射端的差模雜訊。這個平衡式模型可以再一次使用無截角及截角之尾端短路耦合線來實現實際佈局。模擬與量測的結果顯示使用截角之尾端短路耦合線的彎曲差動傳輸線，除了可以進一步降低模轉換與接收端的共模雜訊，並且可以降低發射端的差模雜訊。同時，使用截角之尾端短路耦合線的彎曲差動傳輸線可以維持訊號的完整度。

In order to investigate the differential bend of the bended differential transmission line, a lumped equivalent circuit is adopted. The parameters of the lumped equivalent circuit can be extracted through the de-embedding procedures using ABCD matrix described in Chapter 2. In order to verify the lumped equivalent circuit, a bended differential transmission line using the right-angle bend is fabricated and measured. The measurement result shows that the lumped equivalent circuit could well represent the right-angle bend of the bended differential transmission line.
In order to reduce the mode conversion induced by the differential bend, a bended differential transmission line using a compensation capacitance is adopted by applying the lumped equivalent circuit described in Chapter 2. The compensation capacitance can then be implemented by a parallel plate capacitor in order to take advantage of the PCB process. It has been verified that the bended differential transmission line using the compensation capacitance can greatly reduce the mode conversion and TDT common-mode noise at the receiving end while increasing the TDR differential-mode noise at the sending end. However, the bended differential transmission line using the parallel plate capacitor can slightly reduce the mode conversion and TDT common-mode noise at the receiving end while increasing the TDR differential-mode noise at the sending end. Also, when the bended differential transmission line using the parallel plate capacitor is used, the signal integrity of this circuit will slightly decrease from that of the bended differential transmission line using the right-angle bend.
Besides, in order to efficiently suppress the mode conversion of the differential bend, a bended differential transmission line using a compensated inductance is proposed. The compensated inductance is then implemented by un-chamfered and chamfered coupled lines with short-circuited end in order to take advantage of the PCB process. It has been shown that both the bended transmission lines using the compensated inductance and those using un-chamfered and chamfered coupled lines with short-circuited end can greatly reduce the mode conversion and TDT common-mode noise at the receiving end while increasing the TDR differential-mode noise at the sending end. Also, the bended differential transmission lines using the un-chamfered and chamfered coupled lines with short-circuited end can maintain or even improve the signal integrity of the bended transmission line using the right-angle bend.
Finally, in order to further reduce the TDT common-mode noise and the TDR differential-mode noise, a bended transmission line using a balanced model is proposed. The balanced model can then be implemented by the un-chamfered and chamfered coupled line with short-circuited end. It has been shown that the bended differential transmission line using the chamfered coupled line with short-circuited end can further reduce the mode conversion and the TDT common-mode noise at the receiving end while reducing the TDR differential-mode noise as compared with the bended differential transmission line using the compensated inductance. Also, as compared with the signal integrity of the bended differential transmission line using the right-angle bend, the signal integrity of the bended differential transmission line using chamfered coupled line with short-circuited end is maintained.

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