A number of people, specially students gets confused about the difference between passband and bandpass term. These two terms are interrelated and here we explain the difference between these two terms.

Passband refers to band or range of frequencies over which the user is interested in. In other words it is context dependent. Meaning, for example, if we speak about filters then passband refers to the range of frequencies of the particular filter. All filters-low pass filter, high pass filter, bandpass filter  have passband frequencies. Only bandstop filter does not have passband or passband frequencies.

A low pass filter(LPF) has passband from 0Hz to say fc Hz(cut-off frequency) and attenuates all other frequency signal. A high pass filter has passband from fc to higher frequencies and attenuates all other. Similarly, a bandpass filter has passband from fl to fh and attenuates all other frequencies.

What is difference between Passband and Bandpass?

Bandpass refers to the band of frequencies where are allowed to pass through. A bandpass filter has frequency range fl to fh and any signal with frequency within this range are allowed to pass through the filter. Besides, the passband of the bandpass filter is the same frequency range fl to fh.

Thus, while passband term is a general term used for any range of frequencies, the term bandpass is usually associated with bandpass filter.


Post a Comment