This calculator estimates the radius of the Fresnel zone for a given distance and frequency. It helps determine how much clearance is needed around the line of sight between two antennas to minimize signal loss caused by obstacles.
Formulas
Radius (m) = 17.31 * √( Dkm / (4 * fGHz) )
Radius (ft) = 72.05 * √( Dmiles / (4 * fGHz) )
Formula Explanation
- D is the distance between antennas (in km or miles).
- f is the operating frequency in GHz.
- The constant values ensure unit consistency and simplify calculation.
Example
Input: D = 5 km, f = 2.4 GHz
Result: Fresnel Zone Radius ≈ 19.8 m
Who uses it
Useful for wireless network planners and RF engineers ensuring clear signal paths for microwave, Wi-Fi, and point-to-point links.