Noun
English Wikipedia has an article on:stopbandWikipedia
stopband (plural stopbands)
A band of frequencies in which an electronic filter will not let signals pass through.
A band-stop filter has one stopband, specified by two non-zero and non-infinite corner frequencies. Source: Internet
As is clear from the image, the elliptic filter is sharper than the others, but at the expense of ripples in both its passband and stopband. Source: Internet
Alternatively, a stopband corner frequency may be specified as a point where a transition band and a stopband meet: a frequency for which the attenuation is larger than the required stopband attenuation, which for example may be 30 dB or 100 dB. Source: Internet
Depending on application, the required attenuation within the stopband may typically be a value between 20 and 120 dB higher than the nominal passband attenuation, which often is 0 dB. Source: Internet
In the stopband (s), the required attenuation in dB is above a certain level, for example >100 dB. Source: Internet
The Butterworth filter has the poorest transition but has a more even response, avoiding ripples in either the passband or stopband. Source: Internet