Agilent Technologies 8719ES User Manual page 402

Operating Concepts
Analyzer Display Formats
The default group delay aperture is the frequency span divided by the number of points
across the display. To set the aperture to a different value, turn on smoothing in the
average menu, and vary the smoothing aperture. The aperture can be varied up to 20% of
the span swept.
Group delay measurements can be made on linear frequency, log frequency, or list
frequency sweep types (not in CW or power sweep). Group delay aperture varies depending
on the frequency spacing and point density, therefore the aperture is not constant in log
and list frequency sweep modes. In list frequency mode, extra frequency points can be
defined to ensure the desired aperture.
To obtain a readout of aperture values at different points on the trace, turn on a marker.
Then press . Smoothing aperture becomes the active
SMOOTHING APERTURE
Avg
function, and as the aperture is varied its value in Hz is displayed beneath the active entry
area.
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