Agilent Technologies 8719ES User Manual page 62

Making Measurements
Measuring Electrical Length and Phase Distortion
Figure 1-38 Group Delay Example Measurement with Smoothing
5. To increase the effective group delay aperture, by increasing the number of
measurement points over which the analyzer calculates the group delay, press:
SMOOTHING APERTURE
As the aperture is increased the "smoothness" of the trace improves markedly, but at
the expense of measurement detail.
Figure 1-39 Group Delay Example Measurement with Smoothing Aperture
Increased
Group delay is calculated by dividing the phase difference between points by the frequency
spacing. Thus, if n equals the number of points, the number of phase difference values (or
frequency segments) will be n−1. The first data point is repeated so that the total number
of points remains n.
1-48
5 x1