Definition of neper in English:


Pronunciation /ˈnēpər/ /ˈnipər/


  • A unit used in comparing voltages, currents, and power levels, especially in communications circuits. The difference between two values in nepers is equal to the natural logarithm of their ratio for voltages and currents or to half of this for power differences.

    ‘The dielectric loss in each case is rated in nepers of attenuation at some arbitrary frequency, 0.’
    • ‘The neper is the natural logarithm of the power ratio.’
    • ‘The frequency range covered by the GBT extends from low frequencies where the opacity is relatively low (~ 0.008 nepers) to high frequencies where opacity is very high.’


Early 20th century from Neperus, Latinized form of Napier (see Napier, John).