RF / PCB Couplers

Quarter-Wave Edge-Coupled Microstrip Calculator

Estimate quarter-wave directional coupler length from frequency, PCB dielectric, substrate height, and trace width.

PCB material Frequency GHz Substrate height mm Trace width mm Copper thickness um Custom dk (εr) Custom df (tan δ)

Quarter-wave length -- mm Quarter-wave length -- mil Effective dielectric -- Guided wavelength -- mm

Material	dk (εr)	df (tan δ)	Default height	Use range