Baseband is a
signal that has a very narrow frequency range, i.e. a spectral magnitude that is nonzero only for frequencies in the vicinity of the origin (termed
f = 0) and negligible elsewhere. In
telecommunications and
signal processing, baseband signals are transmitted without modulation, that is, without any shift in the range of frequencies of the signal, and are low frequency - contained within the band of
frequencies from close to 0
hertz up to a higher
cut-off frequency or maximum bandwidth. Baseband can be synonymous with
lowpass or
non-modulated, and is differentiated from
passband,
bandpass,
carrier-modulated,
intermediate frequency, or
radio frequency (RF).