Use this electronics calculation for a first-pass component, converter, signal, motor, or sensor estimate when the stated operating conditions and units match the device data.

Diameter (m)

Largest aperture dimension.

Wavelength (m)

Operating wavelength.

Compute the Fraunhofer far-field distance boundaryMeters = 2 * diameterMeters^2 / wavelengthMeters. The tool evaluates the supplied inputs together and returns the named outputs below; it does not infer omitted operating conditions or change the units shown.^[1]

Far-Field Boundary (m)

Far-field boundary distance from the aperture.

• Antenna formulas assume stated frequency, impedance match, polarization, efficiency, aperture, and propagation geometry. Nearby objects, ground, feed loss, multipath, regulatory averaging, near-field conditions, and pattern variation can make free-space or ideal-aperture results inaccurate.
• Use finite inputs in the displayed units and preserve more precision than the final presentation requires. Independently verify safety-critical, financial, compliance, or production decisions.

Check the result against the current datasheet and worst-case operating corners, then verify the circuit or measurement with simulation and bench testing where failure matters.

• Far Field Boundary

  Compute the far-field boundary of an aperture as Rf = 2 x D^2 / lambda; aperture size and wavelength must be positive.

• Near Field Distance

  Compute the outer boundary of an aperture antenna's reactive near field as Rn = 0.62 x sqrt(D^3 / lambda); dish diameter and wavelength must be positive.

• Beamwidth From Diameter

  Approximate parabolic dish half-power beamwidth in degrees as bwDegrees = 70 * wavelengthMeters / dishDiameterMeters.