High-Frequency PCB Design: Trace Width Considerations

High-frequency PCB designs require special attention to trace width for optimal signal integrity. This guide explains key considerations when using our PCB Trace Width Calculator for RF applications.

Impedance Control Fundamentals

At high frequencies (>100MHz), trace width becomes critical for impedance matching:

Microstrip traces: Width-to-height ratio determines impedance
Stripline designs: Requires precise width control

Example: 50Ω Microstrip

For FR4 substrate (εr=4.5) with 1.6mm thickness:

// Using our Impedance Calculator
Trace Width: 2.8mm
Thickness: 1oz (0.035mm)
Result: 50.2Ω impedance

Skin Effect Considerations

Above 10MHz, current flows primarily at trace surface:

1GHz Signal

Skin depth: ~2.1μm in copper

Effective resistance increases

Design Solution

Wider traces reduce overall resistance

Our calculator includes skin effect

EMI Reduction Techniques

Controlled Return Paths

Maintain continuous ground plane under signal traces

Differential Pairs

Match trace widths precisely for balanced signals

Design Recommendation

Use our High-Frequency Calculator Mode for designs above 100MHz.

Material Selection Guide

Material	Dk (εr)	Typical Use
FR4	4.3-4.8	Up to 2GHz
Rogers 4350B	3.48	2-10GHz
PTFE	2.1	>10GHz

For complex RF designs, consult our Advanced Calculator with material database.

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