Agilent Technologies 86038A User Manual page 50

Measurement Concepts
50
Figure 7 Ripple Error Due to Sideband Separation
The graph shown in Figure 8
modulation frequency for measurement of fine group delay ripple. To use
the chart, follow these steps:
8 Enter the x-axis at the estimated period of group delay ripple to be measured.
9 Draw a vertical line to the curve representing the desired number of
measurement samples per period of the group delay ripple.
10 Draw a horizontal line to the left and right hand axes. Read the wavelength step
and the modulation frequency from the left and right vertical axes, respectively.
To balance the limiting effects of both parameters, the chart in
assumes that the double-sided spectral width of the RF modulation
spectrum is identical to the wavelength increment. Of course, in some
measurement situations it may be appropriate to take smaller wavelength
steps than the chart would suggest. For example, to over-sample, then
post-smooth the data to reduce trace noise. The 86038A provides built-in
smoothing functions for this purpose.
is an aid to selecting the wavelength step and
Agilent 86038A Optical Dispersion Analyzer, Third Edition
Description of the 86038A
Figure 8