Rohde & Schwarz 1145.1010.04/05/06, Operating Manual

Page: 230 / 813

Trace Menu R&S
®
ZVA/ZVB/ZVT
1145.1084.12 4.68 E-6
•
Keep Frequency Gap and Number of Points means that the number of sweep points and their
relative spacing is maintained. The entire set of sweep points is shifted towards lower
frequencies so that the stop frequency is decreased.
•
Keep Stop Frequency and Approximate Frequency Gap means that the stop frequency is
maintained and the and the number of sweep points is increased until the range between f
min
and the stop frequency is filled. The frequency gap is approximately maintained.
The figures above are schematic and do not comply with the conditions placed on the number of
sweep points and interpolated/extrapolated values.
The harmonic grids can not be calculated for any set of sweep points. If the minimum number of
sweep points is smaller than 5, then the interpolation/extrapolation algorithm for additional
sweep points will not work. The same is true if the number of sweep points or stop frequency
exceeds the upper limit. Besides, the ratio between the sweep range and the interpolation range
between f = 0 and f = f
min
must be large enough to ensure accurate results.
If the sweep range for the harmonic grid exceeds the frequency range of the current system
error correction, a warning is displayed.
Finding the appropriate algorithm
The three types of harmonic grids have different advantages and drawbacks. The following table helps
you to find the appropriate grid.