Differential stripline impedance calculate
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This document discusses calculating the impedance of differential striplines using three simulation tools and comparing the results. Saturn PCB Toolkit produced an impedance of 77.51 ohms, Polar Si9000 produced 81.32 ohms. Polar was likely more accurate as it uses an EM field solver approach. The document then explores using ADS to calculate impedances of single-ended and differential microstrips, and analyzes a differential line case using the ADS EM model and TDR analysis.
Differential stripline impedance calculate
- 1. Differential Stripline Impedance Calculate Using 3 Simulation Toolkit 1 Jay Chang
- 2. 按照板廠提供的數據, L4 ref L3/L5算出來的impedance = 77.5 Ω http://www.multek.se/engelska/engineering/pcb-structures- 2/differential-stripline-impedance-calculator-2 2
- 3. Use one of the most popular simulation tool Saturn_PCB_Toolkit_V7.02 按照板廠提供的數據, L4 ref L3/L5算出來的impedance = 77.51 Ω 3
- 4. Use one of the most popular simulation tool Polar Si9000 按照板廠提供的數據, L4 ref L3/L5算出來的impedance = 81.32 Ω 4
- 5. 既然都用Polar惹, 那就算一下 freq dependent behavior Z0 vs freq 5
- 6. 和total loss vs freq 6
- 7. Why Polar Si9000跟前兩個算出來的很接近但不太一樣 因為Polar 是EM field solver (field solver condition代對 就是準!!) field solver分兩大類 1. Differential Maxwell equations 電磁場所在的整個域的離散化(網格化) 解稀疏線性 matrix 代表的有FD(有限差分), FEM(有限元素 HFSS為代表)… 2. integral equation methods 對電磁場的源(通常是電荷密度)進行離散化 解Green function 代表的有BEM(邊界元素 Polar為代表)… 結論: a. QTI算的impedance應該有問題, lossless又是freq independent阻抗應該沒那麼大, initial value不知道有沒有代對 也不知道用甚麼算的(猜是SIWAVE or ADS ?) b. 那time skew FAIL應該就是differential line不等長的關係 先降~ To be continued… 7
- 8. Single-ended Microstrip Impedance Calculate Using ADS 8 • ADS用優化的辦法來求出阻抗 • 先用一個簡單的Microstrip來驗證ADS and Polar的結果是否吻合, 再回到我們與QTI的simulation
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- 17. 17 Our Qlink Case Impedance Calculate Using ADS Optimization
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- 22. 22 Our Qlink Case Impedance Calculate Using ADS EM Model
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- 26. 26 v1: excited voltage與反射電壓的疊加 v2: output端電壓 v3: near end crosstalk (NEXT) v4: far end crosstalk (FEXT)
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- 28. 28 Diff mode excitation Comm mode excitation
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- 30. 30 TDR Analysis Using ADS
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