Symmetric Stripline Impedance Calculator

PCB stripline refers to a type of trace/transmission line that is routed in the inner layers of the PCB. Due to this, it is enclosed by a single material, usually the PCB substrate material. This is most commonly noticed on multilayer PCB designs, where the signal trace is equipped with ground planes both above and below it. Due to this arrangement, the high-frequency signal remains inside the PCB leading to fewer emissions and also provides shielding against incoming signals.

The impedance of the stripline is measured in Ohms and can be determined using this calculator by entering Relative Permittivity of the Dielectric, Height of the trace, trace thickness, width of the trace. Additionally, you can also obtain information such as capacitance, propagation delay, and inductance associated with the stripline using this calculator.

PCB Stripline impedence

Substrate Dielectric
Height of Trace
mm
Trace Thickness
mm
Width of the Trace
mm

Formula

\[z = \frac{60}{\sqrt{e}} ln \left(\frac{1.92 * (2h + t)}{0.8w + t}\right) \]
\[c = \frac{5.55 * 10^{-11} * e}{ln (\frac {3.81h}{0.8w + t})} \]
\[ p = 3.34 * 10^{-9} \sqrt{e} \]
\[ l = c * z * z \]

where :

  • e = Relative permittivity of the dielectric
  • m = Height of dielectric
  • h = Height of trace
  • z = Characteristic impedance
  • w = Width of the trace
  • t = Trace thickness
  • c = Capacitance per unit length
  • p = Effective propagation delay
  • l = Inductance per unit length

Any questions? Drop them here!