Provide values for three of the four parameters H, T, W, Zo and the relative permittivity of the dielectric. Click the button corresponding to the unknown parameter to calculate its value. ( 0.1< W/H < 3.0; 1 < εr < 15 )

Select the dimension unit of the microstrip: mm mils
  

(Dielectric thickness) :	mm mils
(Trace thickness) :	mm mils
(Trace width) :	mm mils
er (Relative permittivity) :
(Characteristic impedance):	ohms
Co    (Capacitance):	pF/cm pF/inch
Tpd  (Propagation delay time):	psec/cm psec/inch

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Notes:

• The formulas used here are taken from the Design Guide for Electronic Packaging Utilizing High-Speed Techniques (4th Working Draft, IPC-2251, February 2001).

• Range of valid parameters specified in the Design Guide: 0.1< W/H < 3.0; 1 < εr < 15;
• Accuracy: For typical PCB parameters (εr = 4, H = 30 mil and T = 1.37 mil), the deviation of the calculated results from results obtained using XFX, a 2D numerical field solver from Innoveda, is listed below:

Zo:
0.1 < W/H < 0.2	within 5%
0.2 < W/H < 1.5	within 2%
1.5 < W/H < 2.0	within 5%
2.0 < W/H < 2.7	within 10%
2.7 < W/H < 3.0	within 15%
Co:
0.1 < W/H < 0.2	within 10%
0.2 < W/H < 1.2	within 5%
1.2 < W/H < 2.0	within 10%
2.0 < W/H < 3.0	within 5%