DELTALINK / RF
Fresnel Zone Calculator
Estimate the first Fresnel radius at an obstacle position and an illustrative clearance target.
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Illustrative link profile
Chart data and units
Engineering notes, formulas & examples
Formula and units
r₁ = √(λ d₁ d₂ / (d₁ + d₂)); clearance = r₁ × percentage / 100
d₁ and d₂ are distances from the selected point to TX and RX, converted to metres. Radius is measured perpendicular to the direct path.
Worked example
At 5.8 GHz over 10 km, midpoint radius is approximately 11.37 m; a 60% target is 6.82 m.
Assumptions and limitations
60% is an illustrative planning guideline, not a universal guarantee. The schematic does not include terrain, obstruction heights, antenna heights, refraction or Earth curvature and cannot prove path clearance.