本論文所提出的雙 U 型缺陷接地結構共模濾波器，主要是在非對稱差動訊號對正下方的金屬層面上蝕刻製作而成。利用相關 3D 模擬軟體，針對雙 U 型缺陷接地結構共模濾波器各物理尺寸參數來進行分析及模擬；利用改變雙 U 型蝕刻開口處的距離，進而影響其耦合關係，以改變非對稱差動訊號對的差模、共模饋入損耗值。
針對非對稱差動訊號對使用本論文所提出的雙 U 型缺陷接地結構共模濾波器，其優點之一是可降低共模雜訊，且不會影響其差動訊號對的差模訊號品質。同時也藉由差模、共模的饋入損耗及眼圖、訊號雜訊比的差異來分析使用雙 U 型缺陷接地結構的非對稱差動訊號對之相關電氣特性，並從中萃取出相關的 RLGC 矩陣及電氣特性參數，並將其電氣特性參數代入相關文獻公式內加以驗證。其優點之二是此雙 U 型缺陷接地結構共模濾波器製作容易、設計成本可有效降低，也可達到衰減共模電流及抑制共模雜訊之效果。 The asymmetric differential signals arrive at different times at the end, It will result in the generation of common mode noise. The common mode noise might result which might then cause timing margins and electromagnetic interference (EMI) problems.
The defected ground structures (DGS) might be utilized in all kinds of filter design. A new double U - shaped common-mode filter on defected ground structures can degrade common mode current and attenuation common mode insertion loss (SC2C1), but will not influence the differential mode insertion loss (SD2D1). The simulated results indicate that
the differential mode insertion loss is less than -3 dB and the common mode insertion loss is less than -3.3 dB (form 0 to 10 GHz). Show in the relevant literature, the insertion loss close to 0 dB, meaning that the entire signals is transmitted the insertion loss the smaller.
This is the double U - shaped common-mode filter advantage. It cans attenuation common mode noise, but will not influence the asymmetric differential signals is transmitted and lower costs.
