边缘耦合差分对称带状线传输线是一种常见的差分走线布线技术。有四种不同类型的阻抗用于表征差分走线阻抗。这个计算器可以找到奇数和偶数传输线阻抗。建模近似可用于了解边缘耦合差分带状线传输线的阻抗。

The edge couple differential symmetric stripline transmission line is a common technique for routing differential traces. There are four different types of impedance used in characterizing differential trace impedances. This calculator finds both odd and even transmission line impedance. Modeling approximation can be used to understand the impedance of the edge couple differential stripline transmission line.

边缘耦合差分对称带状线传输线由两条迹线构成，两条迹线参考迹线上方和下方的相同参考平面。它们之间有介电材料。线路之间也存在一些耦合。这种耦合是差分走线的特征之一。通常，匹配差分走线长度并保持走线之间的距离一致是一种很好的做法。还要避免在这些走线之间放置过孔和其他结构。

An edge couple differential symmetric stripline transmission line is constructed with two traces referenced to the same reference planes above and below the traces. There is a dielectric material between them. There is also some coupling between the lines. This coupling is one of the features of differential traces. Usually it is good practice to match differential trace length and to keep the distances between the traces consistent. Also avoid placing vias and other structures between these traces.

差分阻抗定义 Differential Impedance Definitions

差分阻抗 当两条线用相反极性的信号驱动时测量的阻抗。Zdiff 等于 Zodd 值的两倍

奇阻抗 仅测试一条以接地层为参考的差分走线时测量的阻抗。差分信号需要用相反极性的信号驱动。Zodd 等于 Zdiff 值的一半

Common Impedance 用相同信号驱动两条线路时测量的阻抗。Zcommon 是 Zeven 价值的一半

偶阻抗 仅测试一条以接地层为参考的差分走线时测得的阻抗。差分信号需要用相同的相同信号驱动。Zeven 是 Zcommon 价值的两倍

Differential Impedance The impedance measured between the two lines when they are driven with opposite polarity signals. Zdiff is equal to twice the value of Zodd

Odd Impedance The impedance measured when testing only one of the differential traces referenced to the ground plane. The differential signals need to be driven with opposite polarity signals. Zodd is equal to half of the value of Zdiff

Common Impedance The impedance measured between the two lines when they are driven with the same signal. Zcommon is half the value of Zeven

Even Impedance The impedance measured when testing only one of the differential traces referenced to the ground plane. The differential signals need to be driven with the same identical signal. Zeven is twice the value of Zcommon

微带传输线模型 Microstrip Transmission Line Models

已创建模型来近似微带传输线的特性。Models have been created to approximate the characteristics of the microstrip transmission line.

  for (s/t) >= 5

  for (s/t) < 5

Impedance calculation

Edge coupled microstrip impedances (Z_0,odd, Z_0,even, Z_0,diff and Z_0,common) shall be calculated as specified in previous paragraph.

Example 1

Inputs
T = 1.2 mil
H = 63 mil
W = 10 mil
S = 63 mil
ε_r = 4

Output
Z_odd = 78.4 Ω
Z_even = 78.3 Ω
Z_diff = 157 Ω
Z_common = 39.2 Ω

Example 2

Inputs
T = 1.5 mil
H = 70 mil
W = 15 mil
S = 65 mil
ε_r = 4.3

Output
Z_odd = 68.1 Ω
Z_even = 68.0 Ω
Z_diff = 136 Ω
Z_common = 34.0 Ω

Reference

[1] IPC-2141A “Design Guide for High-Speed Controlled Impedance Circuit Boards”