IEVref: 802-01-20 ID: Language: en Status: Standard Term: beamwidth, Synonym1: Synonym2: Synonym3: Symbol: w Definition: greatest distance between two points on a specified axis perpendicular to the beam axis, where the pulse-pressure-squared integral falls below its maximum on the specified axis by a specified amount Note 1 to entry: Commonly used beamwidths are specified at −6 dB (w6), −10 dB (w10) and −20 dB (w20) levels below the maximum. The decibel calculation implies taking 10 times the logarithm (to the base 10) of the ratios of the integrals. Note 2 to entry: The term "beamwidth" has different meanings in optical fibre communication (see IEV 731-01-35) and in relation to antennae (see IEV 712-02-33). Publication date: 2021-04 Source: Replaces: 802-01-20:2011-01 Internal notes: CO remarks: TC/SC remarks: VT remarks: Domain1: Domain2: Domain3: Domain4: Domain5: