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.

Left Degrees (°)

Required number input.

Right Degrees (°)

Required number input.

Angular separation of the two −3 dB pattern crossings around one antenna main lobe. 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 Degrees (°)

The resulting beamwidth degrees 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 Approx

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

• Beamwidth From Diameter

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

• Antenna Sidelobe Level

  Sidelobe level relative to the main-lobe peak from linear same-reference power measurements.