Microstrip Zo

Microstrip Zo Calculator

microstrip Zo impedance diagram


Trace Thickness
Substrate Height
Trace Width
Substrate Dielectric

Output ⊕

Impedance (Zo): 
138 Ω
Capacitance (C): 
0.402 pF/cm
Propagation delay (Tpd): 
55.4 ps/cm
Inductance (L): 
7.62 nH/cm
DC Resistance (R): 
24.2 mOhm/cm

View Notes

Calculation Notes

A microstrip is a type of electrical transmission line consisting of a conducting strip separated from a ground plane by a dielectric layer called the substrate. The suface microstrip also has free space (air) as the dielectric above it.

Factors that influence the impedance calculation include:-

  • Trace thickness (t)
  • Substrate height (h)
  • Trace width (w)
  • Substrate dielectric (εr)

Z_{o}\approx \frac{87}{\sqrt{\varepsilon_{r}+1.41}}\times\ln\left(\frac{5.98h}{(0.8w+t)}\right)

  • RF Design Guide Systems, Circuits and Equations (ISBN 0-89006-754-6)
  • High-Speed Digital Design (ISBN 0-13-395724-1)
  • Signal Integrity Issues and Printed Circuit Board Design (ISBN 0-13-335947-6)
  • IPC-2141 Controlled Impedance Circuit Boards and High Speed Logic Design

Disclaimer: The information and this tool are provided with no liability of any kind whatsoever, use at your own risk.

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