2.6.4
Phase Response
Phase characteristics of the Model 3945 are shown in Figure 2.2. It provides output phase relative to the
input with the filter operating in the low-pass mode with Butterworth and Bessel response.
2.6.5
Group Delay
Group delay, shown in Figure 2.3, is defined as the derivative of radian phase with respect to radian fre-
quency, which is the slop of the phase curve. A flat group delay is considered a linear phase response
which corresponds to a constant slope of the phase curve. With linear phase response the distortion of
complex data signals will be minimized because their various frequency components, due to a constant
time delay, will not shift relative phase.
Section 2 - Operation
2-7
Figure 2.2 Phase Response
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