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.

Wavelength (m)

Required number input.

Dish diameter (m)

Required number input.

Approximate the parabolic dish half-power beamwidth in degrees as 70 x lambda / D; wavelength and dish diameter must be positive. 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]

Beamwidth (°)

The resulting beamwidth returned as a number.

• 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.

• Beamwidth From Diameter

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

• 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.

• Effective Aperture

  Compute the antenna effective aperture in square meters as Ae = lambda^2 x G / (4 x pi); wavelength and linear gain must be positive.