User`s guide

7-35
Operating Concepts
Noise Reduction Techniques
sufficiently high number of display points to avoid misleading results. Do not use
smoothing for measurements of high resonance devices or other devices with wide trace
variations, as it will introduce errors into the measurement.
Smoothing is used with Cartesian and polar display formats. It is also the primary way to
control the group delay aperture, given a fixed frequency span. Refer to “Group Delay
Principles” on page 7-30. In polar display format, large phase shifts over the smoothing
aperture will cause shifts in amplitude, since a vector average is being computed. The
effect of smoothing on a log magnitude format trace is illustrated in Figure 7-19.
Figure 7-19 Effect of Smoothing on a Trace