Calculate the radius of the first Fresnel zone for wireless links.
Link Parameters
Fresnel Results
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About this calculator
Quick Reference
rRadius (m)
d1, d2Distances to point (km)
fFrequency (GHz)
DTotal Distance (km)
Overview
The Fresnel zone is an elliptical volume around the direct line-of-sight path between a transmitter and receiver. For reliable wireless communication, at least 60% of the first Fresnel zone must be clear of obstacles.
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Pro Tips
The zone is widest at the midpoint between antennas.
Higher frequencies have narrower Fresnel zones.
Obstacles in the Fresnel zone can cause signal cancellation due to out-of-phase reflections.
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Fun Facts
"Augustin-Jean Fresnel originally developed these concepts for optics, but they are now vital for radio engineers."
"Trees, buildings, and the ground itself are common Fresnel zone obstructions."
"The first Fresnel zone contains the bulk of the signal power in a line-of-sight system."
