A low-pass filter is a filter that passes frequencies from 0Hz to critical frequency, fc and significantly attenuates all other frequencies. The critical frequency of a low-pass RC filter occurs when Xc = R and can be calculated using the formula: fc=1/2πRC
A band-pass filter passes all signals lying within a band between a lower-frequency limit and upper-frequency limit and essentially rejects all other frequencies that are outside this specified band
A high-pass filter is a filter that significantly attenuates or rejects all frequencies below fc and passes all frequencies above fc. The critical frequency of a high-pass RC filter occurs when Xc = R and can be calculated using the formula: fc=1/2πRC
The bandwidth (BW) is defined as the difference between the upper critical frequency (fc2) and the lower critical frequency (fc1). BW=Fc2-Fc1
The frequency about which the pass band is centered is called the center frequency , f o and defined as the geometric mean of the critical frequencies. f0= √Fc1fc2
The quality factor (Q) of a band-pass filter is the ratio of the center frequency to the bandwidth. Q = f0/BW
Band-stop filter is a filter which its operation is opposite to that of the band-pass filter because the frequencies within the bandwidth are rejected, and the frequencies above f c1 and f c2 are passed.