Edge Coupled Trace Inductance

Calculate the Inductance of Two Edge Coupled Traces

Introduction

Coplanar traces are common in printed circuit boards. Coplanar traces where one trace is the signal and the other trace is the return path apply to this inductance calcualtor.

Wire Loop Inductance Description

The inductance of the coplanar trace calculation requires 4 variables:

• W – Trace Width
• S – Trace Seperation
• L – Trace Length
• ur – relative Permiablity

This structure requires that these spacings be uniform down the entire length of the trace.

Coplanar Trace Inductance Model.

The inductance of the coplanar trace is:

L_{coplanar}\approx \frac{\mu _{o}\mu _{r}}{\pi}\cosh^{-1}\left ( \frac{s}{w} \right )

Where

\left ( d>>w, w>t \right )