8.3.3.2.3.1 Linear Phase Response

Linear phase filters exhibit constant delay time versus input frequency (that is, constant group delay). Linear phase filters have the property that the time delay is constant from any instant of the input signal to the same instant of the output data, and is independent of the signal frequency. This filter behavior results in essentially zero phase error when analyzing multi-tone signals. However, the group delay is longer than the minimum phase filter, as shown in Figure 49.

Figure 49. FIR Step Response