Chapter 6 PCB Calculators
© National Instruments Corporation 6-3 NI Ultiboard User Manual
Microstrip Equations
The equations used to perform the microstrip calculations are:
Z0 = 87/(sqrt(Er + 1.41)) * ln(5.98*H/(0.8*W+T))
Tpd = 58.35247*sqrt(Er+1.41)
C0 = Tpd/Z0
L0 = C0*Z0*Z0
Embedded Microstrip Trace CalculationsComplete the following steps to perform embedded microstrip trace
calculations:
1. Select Tools»PCB Transmission Line Calculator.
2. Select Embedded Microstrip in the Type drop -down list.
3. In the Input Data area, edit the following fields as desired.
•Input Length Unit—Select mils or millimeters.
•Dielectric Height (H1)—Refer to the figure below.
•Dielectric Thickness (H)—Refer to the figure below.
•Trace Thickness (T)—Refer to the figure below.
•Trace Width (W)—Refer to the figure below.
•Relative Permittivity (epsilon r)—Refer to the figure below.
4. Click Calculate. Results of the calculation appear in the Calculation
Results area. They also appear in the Results tab of the Spreadsheet
View.
5. Click Close to close the PCB Transmission Line Calculator.