the width of a frequency band such that beyond its lower and upper limits any spectral line or any power spectral density of the spectrum of a signal is at least x dB lower than a reference level specified for the type of signal considered Found on http://www.electropedia.org/iev/iev.nsf/display?openform&ievref=702-01-05
the width of a frequency band such that beyond its lower and upper limits any spectral line or any power spectral density of the spectrum of a signal is at least x dB lower than a reference level specified for the type of signal considered