transmission line

Microstrip Impedance

Uses the Wadell / Hammerstad-Jensen closed-form approximation for microstrip impedance. Accurate to within ~1 % for W/H ratios between 0.1 and 10. Commonly used for RF, high-speed digital signals, and USB/HDMI routing.

Inputs

Trace Width (W)(mm)

Dielectric Height (H)(mm)

Trace Thickness (T)(mm)

Dielectric Constant (εr)

FR4 ≈ 4.4, Rogers RO4003C ≈ 3.55

Results

Impedance (Z₀)64.26Ω

Effective εr3.1981Effective dielectric constant accounting for fringing fields

Propagation Delay59.61ps/cm