Fresnel Zone Calculator

A radio path occupies an ellipsoidal region called a Fresnel zone, not just the optical line between antennas. Objects inside the Fresnel zone can cause diffraction loss and multipath fading.

Fresnel radius is calculated from r = √( λ d₁d₂ / (d₁ + d₂) ), where λ is wavelength, d₁ is distance from Antenna #1, and d₂ is distance from Antenna #2.

The plot uses a chord between the two antenna-site ground points. Earth curvature is drawn above that chord. Antennas and obstruction are drawn upward from the curved Earth surface. The Fresnel boundaries are the LOS path plus and minus the selected Fresnel-zone radius.

Disclaimer: These calculations are believed to be accurate, but you must validate all results for critical applications. RF Cafe's calculators are entirely unique code - not "borrowed" from somebody else's work.